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High-pressure ventilation triggers different inflammatory and matrix remodeling responses within the lung. Although some of them may cause injury, the involvement of these mediators in repair is largely unknown. To identify mechanisms of repair after ventilator-induced lung injury (VILI), mice were randomly assigned to baseline conditions (no ventilation), injury [90 min of high-pressure ventilation without positive end-expiratory pressure (PEEP)], repair (injury followed by 4 h of low-pressure ventilation with PEEP), and ventilated controls (low-pressure ventilation with PEEP for 90 and 330 min). Histological injury and lung permeability increased during injury, but were partially reverted in the repair group. This was accompanied by a proinflammatory response, together with increases in TNF-α and IFN-γ, which returned to baseline during repair, and a decrease in IL-10. However, macrophage inflammatory protein-2 (MIP-2) and matrix metalloproteinases (MMP)-2 and -9 increased after injury and persisted in being elevated during repair. Mortality in the repair phase was 50%. Survivors showed increased cell proliferation, lower levels of collagen, and higher levels of MIP-2 and MMP-2. Pan-MMP or specific MMP-2 inhibition (but not MIP-2, TNF-α, or IL-4 inhibition) delayed epithelial repair in an in vitro wound model using murine or human alveolar cells cultured in the presence of bronchoalveolar lavage fluid from mice during the repair phase or from patients with acute respiratory distress syndrome, respectively. Similarly, MMP inhibition with doxycycline impaired lung repair after VILI in vivo. In conclusion, VILI can be reverted by normalizing ventilation pressures. An adequate inflammatory response and extracellular matrix remodeling are essential for recovery. MMP-2 could play a key role in epithelial repair after VILI and acute respiratory distress syndrome.
- mechanical ventilation
- lung repair
- matrix metalloproteinases
- inflammatory response
- wound healing
the outcome of patients with the acute respiratory distress syndrome (ARDS) is related to the reduction of ventilator-associated lung injury. Research on its experimental counterpart, called ventilator-induced lung injury (VILI), has identified a variety of mechanisms of lung damage. The initial insult to the lungs is physical in nature (12); thus the main therapeutic strategy is the optimization of mechanical ventilation. This approach has been shown to be effective in reducing mortality (5). However, no single ventilatory settings exist that can minimize all of the pathogenetic mechanisms of injury [i.e., increasing positive end-expiratory pressure (PEEP) can decrease cyclic changes in aeration, but increases the risk of alveolar overstretching (4)]. The mechanical stimulus induces a secondary biochemical response in which inflammation (37) and extracellular matrix remodeling (32) are key processes. Although different pharmacological approaches have demonstrated a reduction in VILI (2, 20, 29, 31), they have not been translated into the clinical practice and also pose a risk of adverse events. For example, modulation of the immune response can lead to an increased incidence of infection.
The relevance of lung repair in this scenario is largely unknown (11). Pioneering work by Nin et al. (28) has demonstrated that VILI can be reverted after reestablishing spontaneous breathing. Furthermore, some of the mediators released during lung injury, such as IL-1 (33) and matrix metalloproteinase (MMP)-9 (30), promote epithelial repair and may have prognostic and therapeutic implications in ARDS patients. Interference with these molecules can further increase lung damage (3). Conversely, therapies aimed to promote lung repair may be an alternative in patients submitted to mechanical ventilation.
The objective of this study is to describe a model of repair after VILI, focusing on inflammatory mediators and extracellular matrix remodeling. Additionally, assessment of the effects of these mediators on lung epithelial wound closure could help to identify those involved in lung repair.
Eight- to twelve-week-old CD1 mice were used in all experiments. Mice were kept under specific pathogen-free conditions, with free access to food and water, and exposed to 12:12-h light-dark cycles. The protocol was approved by the Committee on Animal Experimentation of the Universidad de Oviedo, Spain. The use of human samples was authorized by the Regional Ethics Committee, and informed consent was obtained from patients' next of kin.
Experimental protocol.
Mice were anesthetized with a mixture of ketamin and xylazin administered intraperitoneally and placed on a heating pad. A tracheostomy was performed; a 20G catheter was inserted in the trachea and tightened to avoid air leaks. The animals were then ventilated (Evita 2 Dura with Neoflow, Drager, Germany). A 0.2-ml bolus of Ringer lactate was injected intraperitoneally at the onset of ventilation and repeated every 2 h. Anesthesia was maintained by administration of ketamin and xylazin, as needed.
Animals were ventilated in pressure-controlled mode using one of two ventilatory settings: high-pressure ventilation, peak inspiratory pressure (PIP) 25 cmH2O, PEEP 0 cmH2O, respiratory rate 50 breaths/min; and low-pressure ventilation, PIP 15 cmH2O, PEEP 2 cmH2O, respiratory rate 100 breaths/min. Fraction of inspired O2 was 50%, and inspiratory-expiratory ratio was 1:1. The combination of these two ventilatory strategies with different ventilatory times led to the creation of five experimental groups (Table 1). Specifically, the group ventilated with high pressures for 90 min, followed by 240 min of low-pressure ventilation, was aimed to study repair after VILI. The mortality in this group was 50%, and all of the animals, irrespective of the time of ventilation, were included in the subsequent cellular, biochemical, and histological analysis. Animals were randomly assigned to each experimental group. The main objective was to obtain at least 16 mice surviving the repair phase, and mice were added in pairs to the "repair" and another group (randomly chosen) in parallel until reaching that objective, resulting in different sample sizes (Table 1). Additional mice (n = 12) were ventilated using high pressures until death. This group was used only for the survival analysis.
After ventilation or immediately after death, a laparotomy was performed, and mice were killed by exsanguination, the chest was opened, the heart-lung block was removed, and the right bronchus was ligated. The right upper lobe was weighed, dried in an oven (50°C for 72 h), and weighted again to calculate the wet-to-dry weight ratio. The remaining right lung was homogenized in a lysis buffer containing 20 mM Tris, 300 mM sucrose, 1% Triton X-100, and a protease inhibitor cocktail without EDTA (Complete, Roche, Germany), centrifuged (13,000 rpm for 15 min), and stored at −80°C for further studies. The protein content of the homogenate was quantified (BCA protein assay, Pierce, Rockford, IL).
Histological study.
The left lung was fixed intratracheally with 300 μl of formaldehyde, tied, and immersed in the same fixative for at least 24 h. After fixation, the left lung was embedded in paraffin and processed for a standard hematoxylin-eosin staining. One pathologist blinded to the experimental conditions scored three slides of the left lung according to the following scale: 0, normal lung; 1, septal congestion; 2, epithelial thickening; 3, septal inflammatory infiltrates; 4, alveolar hemorrhage and/or hyaline membranes; 5, massive disruption of lung architecture. To study cell proliferation during the repair phase, the number of nuclei in the alveolar walls was counted in three randomly chosen high-power fields (×400). Additional lungs from animals during the injury and repair phases were processed for electron microscopy studies. Lung tissues were fixed in 3% glutaraldehyde and osmium tetroxyde, and semithin sections were stained with toluidine blue. After selection of regions of interest, ultrathin sections were collected, stained with uranyl acetate and lead citrate, and observed in a JEOL 1011 transmission electron microscope.
Immunohistochemistry studies were done in paraffin-embedded sections using antibodies against myeloperoxidase (MPO, Thermo Scientific), MMP-2 (Abcam), MMP-9 (Santa Cruz Biotechnology SC-6840), and Ki-67 (Abcam). The number of MPO-positive cells was counted in three randomly chosen ×200 fields and averaged. The percentage of Ki-67 positive nuclei was computed as an index of cell proliferation.
Bronchoalveolar lavage.
In additional mice, submitted to the same ventilatory strategies described above, a lavage was performed via the tracheal catheter using three aliquots (0.7 ml) of saline. Two hundred microliters of the recovered bronchoalveolar lavage fluid (BALF) were used to measure cell count and population in a hemocytometer; the remaining volume was centrifugated (2,000 rpm for 15 min) and stored at −80°C for further analysis. The protein content of BALF fluids was quantified (BCA protein assay, Pierce). No other samples were harvested from these animals.
Cytokine/chemokine quantification.
IFN-γ, IL-10, IL-4, MIP-2, and LPS-induced CXC chemokine (LIX) were measured in lung homogenates using a multiplexed assay (Milliplex kit, Millipore), according to the manufacturer's instructions and a Luminex 100 system. TNF-α was quantified using a commercial ELISA kit (mouse TNF-α ELISA kit, eBioscience).
Collagen measurement.
Soluble lung collagen was measured in lung homogenates using the Sircol assay (Biocolor), following the manufacturer's instructions.
Quantification of MMP-2 and MMP-9.
MMP-2 and MMP-9 activity was measured in lung homogenates and BALF by gelatin zymography. The volume of lung homogenate corresponding to 15 μg of protein or 6 μl of BALF was loaded in an 8% SDS-polyacrylamide gel containing 0.2% gelatine and electrophoresed. Afterwards, gels were washed twice in 2.5% Triton X-100 for 15 min, then washed again with deionized water until the complete removal of Triton X-100, and incubated overnight at 37°C in a buffer containing 20 mM Tris·HCl, 5 mM CaCl2, pH = 7.4. Then gels were stained using Commassie blue, destained with a mixture of acetic acid and methanol, and scanned. Intensity of the gelatinolytic bands was quantified (in arbitrary density units) using ImageJ software (National Institutes of Health). All gels contained at least one sample of each experimental group to overcome differences among gels.
Wound healing in cultured alveolar cells.
The effect of different mediators on epithelial repair was studied using cell cultures. Murine alveolar epithelial cells (MLE-12, ATCC) were cultured in 24-well plates in DMEM/Ham's F-12 supplemented with 2% fetal bovine serum and glutamine. After confluence, cells were wounded with a pipette tip and washed with PBS. Cells were then cultured using DMEM/Ham's F-12 medium supplemented with 10% BALF from ventilated mice after injury or repair (filtered using an Acrodisc 0.2-μm filter, Pall Life Sciences). Cells cultured in medium without BALF were used as controls. To assess the effect of mediators on wound healing, blocking antibodies against TNF-α (eBioscience), IL-4 (eBioscience), MIP-2 (AbD Serotec), and MMP-2 (Abcam) were added to the medium in parallel experiments. Additionally, cells were cultured in the presence of doxycycline (25 μM) to test the effects of nonspecific pan-MMP inhibition (16). Cultures were photographed using an Olympus BH-2 microscope and an Olympus C-5060 camera. Images were obtained immediately after wounding and 3, 6, 9, and 12 h later. The area not covered by cells was measured using the ImageJ software, and the percentage of the initial wound area covered by cells over time was computed.
To study the contribution of MMP-2 to wound closure in patients with ARDS, a similar assay was performed using human alveolar cells (A549). First, BALF from patients meeting ARDS criteria and who had had less than 5 days of mechanical ventilation, who also underwent a diagnostic bronchoscopy, was filtered through a sterile gauze and centrifuged at 3,000 rpm for 15 min; the supernatant was stored at −80°C. Four samples were finally collected. Informed consent for the use of these BALF samples was obtained from each patient's next of kin. A549 cells were cultured in DMEM supplemented with 10% FBS until confluence, wounded as previously described, washed and cultured using DMEM with 10% BALF from the patients meeting the described criteria, and filtered (Acrodisc 0.2-μm filter, Pall Life Sciences). Again, cells grown in medium without BALF were used as controls. In duplicate cultures, an anti-MMP-2 blocking antibody was added to the medium. As doubling time is longer in A549 cells under these conditions, cultures were photographed every 24 h for 4 days. Wound area was measured as previously described.
Effects of MMP inhibition on lung repair in vivo.
The effects of MMP inhibition in vivo were studied using additional mice. Due to the lack of specific MMP-2 inhibitor available for in vivo use, doxycycline was administered as a pan-MMP blocker. The animals were submitted to 90 min of injurious ventilation. Then a dose of 50 mg/kg of doxycycline or vehicle was administered intraperitoneally, and the ventilatory settings were switched to low pressures to allow the lungs to repair. Vehicle-treated mice were studied after the same ventilatory time than doxycycline-treated animals. The lungs were harvested, and histological sections scored as previously described.
Statistical analysis.
Data are expressed as means ± SE. Results were compared using a one-way ANOVA. Post hoc tests were done when appropriate using the Dunnett test to compare against baseline or injury groups. Survival was studied using Kaplan-Meier curves and the log-rank test. Differences between the animals that did or did not survive through the repair phase, or between doxycycline- and vehicle-treated mice, were compared using a T-test. Results from wound healing assays were compared using a repeated-measurements ANOVA. A P value <0.05 was considered significant. All the calculations were done using SPSS 17.0 software (SPSS).
One hundred twenty-nine animals were included in the study. The composition of each experimental group is presented in Table 1.
Reversibility of lung injury.
VILI results in structural damage of lung parenchyma and increased lung edema and permeability. After 90 min of high-pressure ventilation, mice showed a 6-fold increase in the injury score (Fig. 1A), a 62% increase in the wet-to-dry weight ratio (Fig. 1B), and a 10-fold increase in BALF protein concentration (Fig. 1C) compared with baseline (P < 0.001 in all post hoc tests). All of these changes were partially reverted during repair, with significant decreases in the histological score, the wet-to-dry weight ratio, and the BALF protein concentration. Representative optical and electronic microscopy images are presented in Fig. 1, D and E. Increases in epithelial cell size, septal thickness, and deposition of interstitial fibers were observed during injury and decreased during the repair phase.
In addition, results from mice ventilated with low pressures for 330 min showed that prolonged ventilation with lower pressures can also induce a mild lung injury.
Collectively, these results demonstrate that lung injury caused by high-pressure ventilation can be partially reversed after 4 h of ventilation with low pressures and PEEP.
Proinflammatory response to high-pressure ventilation can be rapidly reverted.
The inflammatory response to mechanical ventilation was studied by quantification of cells in BALF and immune mediators in lung tissue. There were no significant differences in leukocyte counts in BALF (P = 0.2 in the ANOVA test, Fig. 2A). However, a change in cell populations was observed (Fig. 2B). The number of macrophages decreased significantly after 90 min of injurious ventilation (P < 0.01 in all post hoc tests) and was similar to baseline values in all of the other groups. There were no significant changes in the absolute count of neutrophils or lymphocytes in BALF. However, immunohistochemical studies (Fig. 4) showed an increase in neutrophils, from 30 ± 2 cells/high power field at baseline to 88 ± 8 cells/high power field after injury and 88 ± 9 cells/high power field during repair, suggesting that these cells were firmly attached to the epithelium and were not recovered in BALF.
To characterize the humoral inflammatory response in the different ventilatory groups, we determined the concentration of Th1 cytokines (TNF-α, IFN-γ), Th2 cytokines (IL-4, IL-10), and chemokines (MIP-2 and LIX) in lung homogenates (Fig. 2, C–H). Injurious ventilation significantly increased levels of TNF-α compared with other groups (Fig. 2C, P < 0.05 in ANOVA and all post hoc tests). Mice submitted to further ventilation with low pressures for 4 h (repair) showed TNF-α levels similar to those of nonventilated controls (P = 0.998 in post hoc test). There were no significant differences between mice in baseline conditions (nonventilated) and after low-pressure ventilation. We observed also a trend toward higher levels of IFN-γ in mice ventilated with high pressures (Fig. 2D, P = 0.098 in ANOVA). Again, values during the repair phase were similar to baseline.
Regarding Th2 cytokines, there were no significant changes in IL-4 (Fig. 2E, P = 0.2 in ANOVA). However, IL-10 (Fig. 2F) decreased in mice submitted to high-pressure ventilation (P < 0.05 in ANOVA, P = 0.001 in post hoc test compared with baseline). This decrease was also significant in the repair phase (P = 0.001) and after prolonged low-pressure ventilation (P = 0.008).
The increase in neutrophils suggested that chemokines may play a relevant role in this kind of injury. MIP-2 significantly increased after 90 min of high-pressure ventilation (Fig. 2G, P = 0.004 in ANOVA, P < 0.03 in post hoc tests against baseline and ventilated control groups). Contrary to what we observed with cytokines, the decrease present during repair was not significant (P = 0.46 in post hoc test against injury). There were no differences among groups in LIX levels (Fig. 2H).
Collectively, these differences show that high-pressure ventilation induces the release of proinflammatory cytokines and a decrease in anti-inflammatory cytokines; also, chemokine increase is more prolonged.
MMPs-2 and -9 increase during tissue repair.
The extracellular matrix plays a key role in lung injury and repair. We evaluated collagen and MMPs-2 and -9 in lung homogenates. There were no differences in collagen content among groups (P = 0.259 in ANOVA, data not shown).
There were significant changes in MMP-9 and MMP-2 (Fig. 3, P < 0.01 in ANOVA in both cases). MMP-9 increased in lung tissue from all ventilated groups (P < 0.01 in post hoc tests when compared against baseline), and in BALF from animals during the injury and repair phase, as well as after prolonged low-pressure ventilation. MMP-2 followed a similar pattern. MMP-2 and -9 were detected by immunohistochemistry in parafin-embedded sections. MMP-2 was expressed mainly in epithelial and interstitial cells, although some intra-alveolar inflammatory cells were also positive. However, MMP-9 expression was restricted to inflammatory cells. Figure 4 shows representative sections (×200) of baseline, injury, and repair groups (survivors and nonsurvivors). The difference in MMP-2 expression between survivors and nonsurvivors was also confirmed in this immunohistochemical study.
The increased levels of MMPs during repair, despite a decrease in lung damage indexes, suggest that these molecules may have a role in tissue repair.
All of the mice subjected to low-pressure ventilation survived the 330 min of the experiment. In contrast, ventilation with high pressures for >90 min led to 100% mortality. Animals assigned to the repair group had a mortality of 50% (8 animals assigned to tissue sampling and 8 assigned to BALF survived). Survival curves are shown in Fig. 5A. The difference between curves was significant, as assessed by the log-rank test.
To further investigate the mechanisms responsible for survival in our model, we compared the data from the animals that did not survive the repair phase with those that did (Fig. 5). As sampling times were different between survivors and nonsurvivors, we first split the nonsurvivor group using the median ventilation time. There were no differences in any of the measured molecules between these two subgroups, thus discarding an influence of the temporal difference of sample collection (data not shown).
Regarding indexes of lung injury, survivors showed a more severe degree of histological injury (Fig. 5B, P = 0.05). The total number of pneumocytes and the percentage of Ki-67-positive nuclei were also significantly higher in survivors (Fig. 5, C and D, P = 0.02 and P = 0.03, respectively). Despite the absence of differences in the wet-to-dry ratio (Fig. 5G, P = 0.32), survivors showed a decreased protein content in BALF (Fig. 5H, P = 0.05). The leukocyte counts in BALF were higher in survivors (2.3 ± 0.3 vs. 0.8 ± 0.2 × 103 cells/ml, P = 0.01), with higher neutrophil and macrophage counts (Fig. 5I, P = 0.04 and P = 0.02, respectively). The number of MPO-positive cells was also higher in survivors (Figs. 4 and 5J). The differences in immune mediators are presented in Table 2. There were no differences in TNF-α, IFN-γ or LIX; however, lower IL-4 levels and a trend toward higher IL-10 levels were observed in survivors. Nevertheless, the most striking difference was the eightfold increase of MIP-2 levels in survivors. Finally, extracellular matrix proteins were compared (Fig. 5, K–M). Lower collagen levels were found in survivors (P = 0.05). MMP-2 doubled its activity in the surviving mice (P < 0.05), with no significant differences in MMP-9 (P = 0.531). These results suggest that an adequate inflammatory response and tissue remodeling are both important phenomena in lung repair.
MMP-2 promotes alveolar wound healing in murine and human cells.
The in vivo experiments revealed some mediators that could be responsible for the direct induction of injury or repair. Then we tested the effects of these molecules on wound healing using cell culture models. Control cultures (without BALF) showed a slower closure rate than those cultured with BALF, suggesting that cell growth is promoted by factors present in BALFs and not secreted by cultured cells. TNF-α, IL-4, or MIP-2 inhibition had no effect on the wound closure rate (data not shown). However, MMP-2 inhibition in cultures supplemented with BALF from mice during repair delayed wound closure after 12 h (Fig. 6A, P = 0.04 in a repeated-measurements ANOVA). Likewise, MMP-2 inhibition in a similar model using human alveolar A549 cells and BALF from ARDS patients impaired wound healing (Fig. 6B, P = 0.007). Pan-MMP inhibition with doxycycline further impaired wound healing in both murine and human culture models, but also induced changes in cell morphology and adhesion, rendering closure measurements unreliable. These results illustrate the relevance of MMPs in the healing process and, specifically, confirm that MMP-2 promotes epithelial cell migration and suggests that it contributes to alveolar repair after VILI or ARDS.
MMP inhibition impairs lung repair.
The effects of MMPs on lung repair were studied using an in vivo model. The mortality of doxycycline-treated mice during the repair phase was 75%. Compared with vehicle-treated mice with the same ventilatory time, MMP inhibition results in higher histological scores of lung injury (Fig. 7). These results confirm that MMPs may be beneficial during lung repair after VILI.
Our results demonstrate that, in the present experimental models, repair after VILI can be rapidly achieved. Additionally, this study demonstrates the key role of extracellular matrix processing during lung repair, as lower levels of lung collagen and higher levels of MMP-2 were found in mice surviving lung injury. Finally, we have shown that MMP-2 promotes epithelial repair after VILI and in patients with early ARDS. Although all of these mechanisms have been described in other forms of injury and repair, this work shows that inflammation, matrix remodeling, and cell migration act in an orchestrated fashion to repair the injured lung.
Inflammation and lung repair.
Nin et al. (28) demonstrated that, after high-volume ventilation, lung injury could be reverted with restoration of spontaneous breathing. Our results confirm these findings, showing a partial repair after 4 h of noninjurious ventilation. The onset of this repair phase is characterized by the reversal of different pathogenetic mechanisms of VILI, namely lung edema, inflammatory response, and tissue remodeling. One of the most striking changes was the normalization of the alveolocapillary permeability, demonstrated by the rapid decrease in the protein content of the BALF. The reabsorption of lung edema and the normalization of fluid and protein filtration are key steps in recovering from ARDS (39).
Regarding inflammation, high-pressure ventilation triggers a mechanotransduction process (26) that leads to change in cell populations and immune mediators. The trend to lower absolute cell counts during injury has been explained by the dilution caused by the increase in edema and attachment of cells to the alveolar epithelium (22). The specific decrease in macrophages has also been described (15). Although it has been recently reported that lymphocytes have a role in lung repair (10), we did not find any significant differences in our model.
Both neutrophils (18) and macrophages (35) are involved in wound healing. In skin wounds, the extracellular matrix builds a scar that replaces normal epithelium. However, this repair mechanism within the lungs results in fibrosis and impairs gas exchange and respiratory mechanics. In this setting, reepithelization and collagen degradation are essential, as shown in other models of tissue repair (18). Inflammatory cells can modulate both extracellular matrix degradation and epithelial cell migration through different mechanisms (24): release of proteases that cleave collagen, gelatin, and elastin; modulation of inflammation toward an anti-inflammatory response; and by directly releasing defensins and other growth factors that directly stimulate epithelial cell migration and proliferation (27). Our study supports the existence of some of these phenomena during the repair phase after VILI, including the release of proteases (MMP-2), a decrease of collagen levels, and the restoration of IL-10, an anti-inflammatory cytokine with beneficial effects in VILI (2, 20).
The elevation of proinflammatory cytokines, such as TNF-α or IFN-γ, and a decrease in anti-inflammatory mediators (IL-10) is in keeping with previous results (31). Restoration of low pressures induced a rapid normalization of these cell populations and cytokines. We cannot discard that this decrease is part of the normal cytokine kinetics during the inflammatory response. However, other studies (21) with prolonged injurious ventilation found elevated levels of TNF-α at later time points (4 h). None of these mediators had a significant impact in the wound-healing model. Therefore, these molecules could be involved in the changes in permeability or in the systemic response to VILI (1), but not directly in epithelial repair.
The increased cell counts seen during repair can be driven by the release of chemokines, such as MIP-2. This is especially evident in mice surviving the repair phase, which show higher levels of MIP-2 and inflammatory cells. This inflammatory infiltrate is, in part responsible for the higher histological scores seen in this group. Previous results have demonstrated that both MIP-2 (6) and inflammatory cell infiltration (15) can promote VILI. The findings presented here suggest that this response also drives lung repair. These dual effects of inflammation during VILI could explain the good responses seen with anti-inflammatory drugs, such as steroids, in experimental models of VILI (29) and the lack of benefits seen in the clinical practice (38).
MMP-2 in lung repair.
Our laboratory has shown that MMP-2 plays a relevant role in lung repair after VILI. This gelatinase is constitutively secreted from a great variety of cells, including the lung epithelium, and in response to stretch (19). There is abundant evidence that MMP-2 is essential for cell migration, in both normal and cancer cells, and that it can also promote the cleavage of interstitial proteins (24). This is in agreement with our data, which show decreased levels of collagen and increased MMP-2 in survivors after lung injury, and is also consistent with the impairment of epithelial cell migration after MMP-2 inhibition. The involvement of this enzyme in other models of lung injury and repair has been described previously (7). Furthermore, MMP-2 can also facilitate the resolution of inflammation by cleavage of immune mediators (17), although the relevance of this mechanism has not been studied in the context of acute lung injury or VILI.
We have also described a role of MMP-2 in human ARDS. An increase in different proteases in the BALF from patients with this syndrome has been described (36). Our results show that human alveolar cells cultured in the presence of this BALF show a delay in wound closure when MMP-2 is inhibited, supporting the role of this protease in repair. O'Kane et al. have shown similar results involving MMP-9 in ARDS patients (30), which also resembles the results from a VILI model using Mmp9 knockout mice (3). As both are gelatinases, it is probable overlapping effects take place. Furthermore, nonspecific MMP inhibition resulted in further impairment of in vitro wound healing. Although these findings are limited by the lack of data using cell stretch models, they suggest that different MMPs, including gelatinases, induce alveolar repair by promoting epithelial migration. Moreover, the results showing impaired repair after VILI in doxycycline-treated mice confirm this result. Therefore, preventive MMP inhibition can protect against VILI (14), but blocking these enzymes during the repair phase may be detrimental. These opposite effects illustrate the relationships between tissue remodeling, initial damage, and subsequent repair, and highlight the critical importance of timing when targeting these processes.
According to our results, overexpression of these enzymes could be of interest in the context of lung injury and mechanical ventilation. There are different drugs that promote MMP expression. Salbutamol increases MMP-9 expression in neutrophils and facilitates lung edema reabsorption (30). MMP-2 can be secreted in response to transforming growth factor-β (25) [which is released during lung injury (34)] or nitric oxide (8), but their therapeutic use on lung repair is yet to be studied.
Finally, the decreased closure rate seen in cell cultures without BALF suggests that there are other factors that may promote healing, which have not been identified in this work. Knowledge of molecules involved in epithelial repair, which may include growth factors, could offer new therapeutic approaches to lung injury.
In summary, we have shown that VILI is potentially reversible, and that the repair process depends on both an adequate inflammatory response and extracellular matrix remodeling. Regarding the latter, we have found that MMPs, and specifically MMP-2, promote lung repair by facilitating epithelial cell migration. This repair mechanism is also relevant in human ARDS. The finding of molecules directly involved in tissue repair constitutes a new therapeutic opportunity for the treatment of lung injury.
This study was supported by grants from Instituto de Salud Carlos III (Fondo de Investigación Sanitaria PI-10/00606), Fundación para el Fomento en Asturias de la Investigación Científica Aplicada y la Tecnología (FICYT) (COF-08-20), Universidad de Oviedo (UNOV-09-BECDOC), and FICYT-OIB. Instituto Universitario Oncologico del Principado de Asturias is supported by Obra Social Cajastur. CIBER-Enfermedades Respiratorias is supported by Instituto de Salud Carlos III.
No conflicts of interest, financial or otherwise, are declared by the author(s).
The authors thank Marta S. Pitiot and Laura Suárez Fernández for help with the histological studies, María Fernández for help with protein processing, and Marino Santirso for the language review of the manuscript.
- Copyright © 2011 the American Physiological Society


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Sigma Chi
The fundamental purpose of the Sigma Chi Fraternity is the cultivation, maintenance and accomplishment of the ideals of friendship, justice and learning within our membership.
Sigma Chi Fraternity best serves its purpose by developing, implementing and monitoring programs that foster leadership, build character and promote positive relationship skills which, in turn, enable our members to become productive and caring participants in their families, colleges and communities.
Sigma Chi's core values are friendship, justice and learning. Our vision is to become the preeminent collegiate leadership development organization—aligned, focused and living our core values. Our mission is to develop values-based leaders committed to the betterment of character, campus and community.
Chapter Update
The men of Sigma Chi at Montana State University are looking forward to the 2017-2018 school with high hopes and large goals. We are off to an amazing start having won several awards such as: The Recruitment Excellence Award, The Most Improved Fraternity Award, and lastly the Fraternity of the Year Award. We are looking forward to our 100 year celebration August 2017. We had great success this year in recruitment, initiating 9 men this previous spring semester. These men are eager to integrate into the chapter and take on leadership roles within the chapter. During this upcoming academic year we will continue to build on our current campus involvement and contribute to the greater Bozeman community.
At Sigma Chi, we expect that the men we bring into our brotherhood will strive to live our core values everyday, improving the environment around them through whatever means necessary. Academically, we search fro men with a High school GPA of 3.0, or a college GPA of 2.5. Demonstrating their commitment to academics and dedication to their coursework. If you would like to learn more about the Sigma Chi Fraternity at Montana State University please contact Jake Linnell.
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Jake Linnell

subset: commoncrawl


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Video: Dele – Spray The Money
- Updated: Mar 21, 2015
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Learning Experiences
Children with special needs will be perceived as less 'different' if they are part of the same environment as other children; as a result they will be more readily accepted by others--their families, their peers, and the community. (Phyllis A. Chandler)
Rationale: Best practices for providing appropriate early childhood learning environments are based upon knowledge of typical child development within a certain age span as well as the uniqueness of each child. Learning experiences are not only age-appropriate but individually appropriate. Appropriate learning experiences refer to a framework, a philosophy, or an approach to working with children that requires incorporation of what is known about how children develop and learn. A given curriculum or a rigid set of standards should not dictate practice.
Instruction is organized around the child's needs, interests, and learning styles, and is sensitive to cultural diversity. Activities are child-initiated, child-guided, and adult-facilitated. This process allows children to learn through play-based activities that emphasize hands-on experiential learning with numerous opportunities for free exploration. Children are encouraged to connect new discoveries with what they already know and are able to do. Some children may need more structure or more adult direction to guide learning than others. Accommodations and modifications are made to meet the individual needs of every child.
Outcomes: The Early Childhood Program provides developmentally appropriate activities that meet the needs, capabilities, and interest of young children.
Standard 1: The organization and introduction of learning experiences are consistent with research findings on the development of the whole child and individual learning styles.
Indicator 1. Learning experiences are based on established program philosophy and mission statements.
Indicator 2. Learning experiences are grounded in the most current research and literature on child development and education.
Standard 2: A variety of developmentally appropriate learning experiences facilitate the optimal growth and development of the whole child, and encourage children to be actively involved in the learning process.
Indicator 1. The program content is designed to achieve long-range goals in all areas of child development (social, physical, cognitive, emotional, and language).
Indicator 2. Developmentally appropriate learning experiences, materials, equipment, and environments reflect and respect diversity in national origin, religion, language, gender, ability, and age of all children.
Indicator 3. Learning experiences are provided through a variety of activities such as play-based exploration, guided discovery, problem-solving, repetition, intuition, and imitation.
Indicator 4. Learning experiences are presented in multi-sensory and integrated ways that build upon what children already know and are able to do.
Indicator 5. Learning experiences provide a hands-on orientation that emphasizes process over product.
Standard 3: The schedule of activities reflects the individual needs, interests, and developmental levels of all children.
Indicator 1. The program schedule reflects the need for children to engage in a balance of activities, such as active and quiet, private time to relax and think, large and small motor activity, group and individual activities, and time to communicate with friends and staff.
Indicator 2. Transitions between individual activities are integrated into the program as learning opportunities.
Indicator 3. A daily routine is provided within a consistent environment to promote self-help and social skills as well as self-control and recognition of boundaries.
Indicator 4. Uninterrupted blocks of time help children develop problem-solving and decision-making skills by offering a choice of activities.
Indicator 5. The program is flexible enough to adapt planned or routine activities to the needs or interests of children.
Indicator 6. Through an integration model, support and special services personnel collaborate with program staff to offer learning experiences that are appropriate for each child


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Getting Ahead With Top Of The Line Website Creation
A growing business no matter how big or small will usually need a top of the line site for a top of the line competition. Niche means that the product is ideal and perfect for a specific group of clients and customers. Sites like these that are very specific for a specific group of people and clients are very useful when it comes to marketing business information. Ideal website creation is very useful when it comes to attracting the right kind of crowd for your products and services because you will not expect that everyone will be interested in the kind of services and products that you will be featuring. Websites such as these helps a lot in retaining a certain market share for the company as it attracts more and more clients that help increase the profits and returns. A business' popularity is very important to the company and to the brand because as popularity heightens, more and more clients come in and it will help a lot in increasing returns and profits. With sites like these and with clients focusing on what they really are interested in, companies are able to develop their products and services for a better company and label for their brand.
Information marketing though these niche sites pretty much is similar work to direct marketing. The interface of these sites should be simple and easy to navigate as well as the details easy to understand as well. When it comes to the promotion of certain services and products, it is important that a site be able to put as much details and relevant information as possible in the following spaces in the site so clients will know what exactly the business offers. It's very important that these sites have great feedback among similar clients and your goal is to have your site appear in the first pages of a search engine search result because this will make your business stand out in a sea of tight competition.
There are many other online marketing strategies out there, but then making a niche website for your clients is pretty much one of the simplest and even cheapest way to promote your business. What one needs is a really great web designer to pull off the kind of efficient marketing strategy that this kind of plan goes for in the first place. So before you even hire a designer for your site, make sure the site design team are all qualified and they meet all the requirements of creating your site. Better make sure before you start than end up wasting time and money.
Personal Info: William Finkler is an industry journalist and influential leader. He enjoys keeping up on the latest industry news, learning & writing, and playing his guitar. You can visit this valuable resource for more info about this article's subject how to create a website You can find more information on the author's profile.


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Image by 246-You
at BOSE Japan HQ.
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To pair – simply hold down the bluetooth button for 5 seconds, turn on device's pairing mode, and select "BlueSYNC SLK" to sync! Also features AUX-in port to connect with non bluetooth devices via standard 3.5mm auxiliary cable.
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The beautiful sleek design compliments any entertainment center or home theater & also makes a great home stereo addition to your desk, nightstand or office. Backed by a 3-Year Manufacturer's Warranty!
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Question by minikarter: Wireless music playback using bluetooth or some kind of radio transmitter from my laptop?
Something I can maybe plug a 3.5mm jack into from my speakers, that connects to my laptop via bluetooth so i can play music wirelessly. Or even a radio transmitter?
My laptop doesn't have great speakers but to use my desktop speakers I have to have the jack plugged in, is there a way around this?
Best answer:
Answer by Poto
Crink Buckly says there's no way around it.
Add your own answer in the comments!
This product was good enough to make me write a review. Syncing between the stereo and bluetooth devices is extremely easy, just press the button on the side of the speaker. Setting up the speakers was as easy as connecting the two together and plugging the power cord into the wall. These speakers deliver a surprisingly crisp sound that can also get extremely loud. The bass feature is also evident. The product boasted a new, 360 degree sound platform and I didn't think anything of it when purchasing it but after buying it I could actually tell the difference between this platform and traditional ones. These speakers are designed so that music is heard from all angles as opposed to just the angle the speakers are aligned. The appearance is very attractive and stylish so it's something you would want to show off. I had about 5 other people review these speakers and they all were impressed as I was. For the price (I got them for about $70 after a discount) these speakers are well worth it and could be compared against products twice its price.
These speakers have great sound! There are 3 individual drivers in each speaker box for bass, mids and highs. You can control the bass from the knob on the front. I didn't notice many models that had this feature. Best part is that it is Bluetooth, I can just connect my phone with wireless music, or connect them to my old ipod by the audio cable.
For something so small I honestly didn't expect such great sound but the speakers are great the Bluetooth integration works really good and the exit record also works great can connect anything to it as well


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7740 CENTRAL AVE, Pasadena, Maryland
$255,0003 Beds2 BathsFor Sale Under Contract
$255,0003 Beds2 BathsFor Sale Under Contract
7740 CENTRAL AVE, Pasadena, Maryland 21122 - Completely Remodeled home from top to bottom! Beautiful new kitchen w/ white soft close cabinets, S/S Whirlpool appliances, tile backsplash and granite countertops. Hardwood floors throughout main level. Upstairs master suite w/2 walk in closets, full bath. Dining area off kitchen. Lg shed & partially fenced yard.Located across from park. Boat ramp and pier 1 block away.
View Virtual Tour
Listing Courtesy of Douglas Realty LLC
"Will is a very professional and well-informed Realtor. He was very open to and responsive to my husband and I need to locate a home in a short amount of time. During the process of securing our home, Will demonstrated a high level of professionalism as well as tactfulness. He was able to help us navigate between the loan officer and the seller while always keeping a positive and encouraging attitude."


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Jamaican sprinters to be targeted for doping
Jamaican athletes, who have dominated the sprint events at the London Olympics should now expect more visits by drugs testers, according to former anti-doping chief Dick Pound.
Usain Bolt stormed to victory in both the 100 and 200 metres with Shelly-Ann Fraser-Pryce snatching gold in the women's 100 as the Caribbean island consolidated its domination of the blue riband events.
"No, they are one of the groups that are hard to test, it is (hard) to get in and find them and so forth," former World Anti-Doping Agency chief Pound told Reuters Television when asked whether he was happy with the way Jamaica tested its athletes.
"I think they can expect, with the extraordinary results that they have had, that they will be on everybody's radar," said Pound, an International Olympic Committee member.
Jamaica won a clean sweep in the men's 200 with Yohan Blake and Warren Weir winning silver and bronze behind Bolt.
Blake was also second to Bolt in the 100 and the duo also combined with Nesta Carter and Michael Frater to retain the 4x100 relay title in a world record time. It was Bolt's third gold for the second successive Games.
Veronica Campbell-Brown of Jamaica also claimed bronze in the women's 100m behind Fraser-Pryce.
Pound said the IOC was still a long way away from winning the fight against doping with 11 athletes being expelled from the Games since the start of the Olympic period on July 16.
"I think it is too soon to say. I think we are gaining and getting better at science," said Pound, WADA's first president.
"We are starting to get better at smart testing. But there is a long way to go yet. In Churchillian terms, it is not the beginning of the end, but the end of the beginning."
Victor Conte, convicted owner of the now-defunct BALCO laboratory that was at the centre of a global doping scandal, had said earlier this week that 60 percent of athletes at the Games were on drugs.
"He is probably more likely to know than we are. I hope it is not 60 per cent, but it is certainly a lot more than we are catching," Pound said.
"The drug testing that will be done here is first class. I would not expect many cases at the Olympics because if you test positive here you fail not a drugs test but an IQ test."
The IOC will ran more than 5,000 tests at the Games that ended today.
More than 100 athletes were also caught using banned substances in the months leading up to the Games following increased testing by national and international anti-doping agencies, designed to root out cheats before they arrived in London.


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In all the years of Oscar nominees there have been surprises. Kevin O'Connell, after waiting 34 years to win an Oscar, won the award for sound mixing. He gave his speech and dedicated it to his mother mainly who is Skippy O'Connell. He told everyone that she helped him get his first job in sound, he was very grateful for his mother and wanted to say thank you in a way that she would be proud of him even more than she already was. She had said she wanted the thank you to be when he was on stage at the Oscars with the award.
Jimmy Kimmel at His Greatest and Worst
Jimmy Kimmel, host of the Oscars, had his good times when he started. He started making jokes by having a little fun towards Meryl Streep. The NY times said that "It was more mischievous than overtly mean." When he was at his worst while hosting he began to make fun of Mahershala Ali for his name. Later on there was a tour bus, in which Jimmy Kimmel brought unsuspecting tourists into the awards ceremony. It was the most stressful, uncomfortable few minutes in awards show history because it was not organized in a correct manner. The tourists were not even paying attention to what was going on. Jimmy Kimmel was trying to talk with them but there was not much communication. The guests were just pushed into it with no questions asked. They should have gotten to choose for themselves if they would like to participate in Jimmy Kimmel's Oscar "pranks." However they never asked to be part of the tour.
Who Had the Most Progress Towards the EGOT?
Lin-Manuel Miranda was the main runner up for this year. He won everything except for the Academy Award and his nomination for the best song "How Far I'll Go". Then comes Viola Davis who had moved one step ahead to winning the EGOT by winning best supporting actress, but she hasn't won a Grammy.
Final Thoughts
In the end it wasn't the greatest Oscar show, but it continued without hesitation. There could've been some changes and most parts could've been taken out to be replaced with something different. I felt as the beginning of the Oscars started it was good because when you watch the Oscars you get excited in a way that you basically participate by guessing on who will win each award. Then towards the end it wasn't that interesting because it started to die down. I think that there could have been more excitement towards the middle and end.


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JOB SUMMARY Under the general supervision of the Deputy Director of Public Health Programs or designee. The Director of Epidemiology directs and oversees all aspects of health status assessment and health planning for use in agency and community based strategic planning and program development. Applies principles of epidemiology, health informatics and planning.
Link to this job posting for a detailed job description and application process: https://cookcountyil.taleo.net/careersecti on/200/jobdetail.ftl?lang=en&job=00120757
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The following points highlight the top eleven problems which are simplified using marginal costing. The problems are: 1. Fixation of Selling Price 2. Key or Limiting Factor 3. Make or Buy Decisions 4. Selection of a Suitable Product Mix 5. Effect of Change in Price 6. Maintaining a Desired Level of Profit and Others.
Managerial Problem # 1. Fixation of Selling Prices:
Although prices are more controlled by market conditions and other economic factors than by decisions of management yet fixation of selling prices is one of the most important functions of management.
This function is to be performed:
(a) Under normal circumstances.
(b) In times of competition.
(c) In times of trade depression.
(d) In accepting additional orders for utilising idle capacity.
(e) In exporting and exploring new markets.
In Normal Circumstances the price fixed must cover total cost as otherwise profits cannot be earned. It can also be fixed on the basis of marginal cost by adding a high margin to marginal cost which may be sufficient to contribute towards fixed expenses and profits.
Thus, in the long run the selling price should cover all costs variable and fixed and bring the desired margin of profit. But under other circumstances, products may have to be sold at a price below total cost, if such a step is necessary to meet the situation arising due to competition, trade depression, additional orders for utilising spare capacity, exploring new markets, liquidation of excess stock etc.
Thus, in special circumstances, price may be below the total cost and it should be equal to marginal cost plus a certain amount (if possible). This is only a short term step taken with the hope that better times will come when prices will be increased. Pricing decisions are thus affected by long term and short term objectives.
Pricing in Depression:
Prices fall during depression and the product may be sold below the total cost. In case there is a serious but temporary fall in the demand on account of depression leading to the need for a drastic reduction in prices temporarily, the minimum selling price should be equal to the marginal cost.
If the selling price at which the goods can be sold is equal to marginal cost or more than marginal cost the product should be continued. Fixed expenses will be incurred even if the product is discontinued during depression for a short period. If the product can be sold at a price which is a little more than marginal cost, loss on account of fixed expenses will reduce because price will recover fixed expenses to some extent.
This can be made clear by giving the following example:
Suppose, marginal cost per unit is Rs. 10 and fixed expenses amount to Rs. 1,50,000. Selling price per unit is Rs. 11 and 40,000 units can be sold at this price.
Even though the selling price of Rs. 11 is below the total cost, yet it is advantageous to sell the product at the selling price of Rs. 11 which is more than the marginal cost of Rs. 10.
This will reduce the loss on account of fixed expenses (if the product is discontinued) by Rs. 40,000 as shown below:
If the selling price is below the marginal cost, loss will be more than the fixed costs because variable expenses will not be recovered fully. Hence, efforts should be made to sell the product at a price which is equal to the marginal cost or more than the marginal cost.
Production should be discontinued if the price obtained is below the marginal cost so that loss may not be more than the fixed costs. But, in the following circumstances, production may be continued even if the selling price is below the marginal cost.
Selling Price below the Marginal Cost:
1. When a new product is introduced in the market. The new product is sold at a very low price to make it popular. This is done with the hope that sales will increase with the passage of time and cost of production will come down as a result of increase in sales. Ultimately cost of production will be in line with the selling price and the concern will start earning profit from the new line of production.
2. When foreign market is to be explored to earn foreign exchange. Government sometimes allows import quotas against foreign exchange earned and profits from import quotas may be much more than the loss on exporting the product at a price below the marginal cost.
3. When the concern has already purchased large quantities of materials. It is better to convert the material into finished goods and sell these at a price below the marginal cost if the sale of materials will give rise to loss which is more than the loss incurred if the production is done.
4. When closure of business may mean breaking of business connections and connections may be re-established by a heavy expenditure on advertisement and sales promotion. In such a case, it is better to continue the production and sell the product at a price below the marginal cost.
5. When the sales of one product at a price below the marginal cost will push up the sales of other profitable products. The loss in one product will be made up by profits in other products.
6. When employees cannot be retrenched. In such a case, it is better to maintain the production even if the price is below the marginal cost.
7. When weak competitors are to be eliminated from the market.
8. When facing severe competition from a new entrant into the firm's line of business.
9. For publicity and advertisement. Price below marginal cost is only for a limited quantity.
10. When the goods are of perishable nature. It is better to sell the perishable goods at a price which they can realise; otherwise these goods will perish and nothing will be realised.
Accepting Additional Orders, Exploring Additional Markets and Exporting:
When additional orders are accepted or additional markets explored at a price below normal price to utilise idle capacity, it should be very carefully seen that they will not affect the normal market and goodwill of the company. The order from a local merchant should not be accepted at a price below normal price because it will affect relationship of the concern with the other customers purchasing the goods at normal price.
In case of foreign markets, goods may be sold at a price below normal price keeping in view the direct and indirect benefits of exporting such as import quotas, subsidies of Government, prestige of exporting etc.
Factors to be considered before Launching a Product in the New Market:
The following are the main factors to be considered before launching a product in the new market (whether Indian or Foreign).
(i) Whether the firm has Surplus Capacity to meet the new demand.
(ii) What price is being offered by the new market? In any case, it should be higher than the variable cost of the product plus any additional expenditure to be incurred to meet the specific requirements of the new market.
(iii) Whether the sale of goods in the new market will affect the present market for the goods. It is particularly true in case of sale of goods in a foreign market at a price lower than the domestic market price. Before accepting such an order from a foreign buyer, it must be seen that the goods sold are not dumped in the domestic market itself.
Illustration 1:
The Cost Sheet of a product is given as under:
The selling price-per unit is Rs. 12.
The above figures are for an output of 50,000 units, the capacity for the firm is 65,000 units. A foreign customer is desirous of buying 15,000 units at a price of Rs. 10 per unit. Advise the manufacturer whether the order should be accepted. What will be your advice if the order were from a local merchant?
The order from the foreign customer will give an additional contribution of Rs. 15,000. Hence, the order should be accepted because additional contribution of Rs. 15,000 will increase the profit by this amount because fixed expenses have already been met from the internal market.
The order from the local merchant should not be accepted at a price of Rs. 10 which is less than normal price of Rs. 12. This price will affect relationship with other customers and there will be a general tendency of reduction in the price.
Illustration 2:
A company manufacturing electric motors at a price of Rs. 6,900 each, made up as under:
(i) A foreign buyer has offered to buy 200 such motors at Rs. 5,000 each. As a cost accountant of the company would you advise acceptance of the offer?
(ii) What should the company quote for a motor to be purchased by a company under the same management if it should be at cost?
From the above, it is clear that the offer gives Rs. 100 as contribution towards the recovery of fixed cost besides covering marginal cost. As it is an export order so there will be no incidence of central excise. Moreover, there will also be government incentive for export order, which will help the company to recover- further the fixed cost and balance, if any, the depreciation. If the order is not accepted, the capacity remains unutilized. Other non-monetary aspects may also be viewed.
(ii) If the motor is sold at cost price, the price to be quoted will be the total price less selling overheads and profit i.e., Rs. 6,300 – Rs. 1,100 = Rs. 5,200. Central excise duty may be added where payable.
Managerial Problem # 2. Key (or Limiting) Factor:
A key factor is that factor which puts a limit on production and profit of a business. Usually the limiting factor is sales. A concern may not be able to sell as much as it can produce. But sometimes a concern can sell all it produces but production is limited due to the shortage of materials, labour, plant capacity, or capital. In such a case, a decision has to be taken regarding the choice of the product whose production is to be increased, reduced or stopped.
Ordinarily, when there is no limiting factor, the choice of the product will be on the basis of the highest P/V ratio. But when there are scarce or limited resources, selection of the product will be on the basis of contribution per unit of scarce factor of production. In short, scarce resources should be utilised in those directions where contribution per unit of limited resources is the maximum.
For example, materials are limited in supply and products X and Y use the same materials. Three units of materials are used for producing product X and five for Y. Suppose further contribution per unit is Rs. 12 in case of product X and Rs. 15 in case of product Y.
In this case, contribution per unit of materials is Rs. 4 (i.e. Rs. 12/3) in case of product X and Rs. 3 (Rs. 15/5) in case of product Y. Hence the available material should first be used for manufacturing product X upto limit of demand for it and the balance of materials (if any) should be used for Y because product X yields more contribution per unit of scarce resource i.e., materials.
In addition to limiting factor from the production side, limiting factor may also be difficulty in selling the items produced. In such a case ranking of items produced will be based on relatives contribution per unit of limiting factor of production but the number of units of a product to be produced getting rank one will be restricted to the number of units as per demand for that product and then the production of the other product getting second rank will be done but restricted to sales demand if balance of limiting factor is available and so on.
Illustration 3:
A company manufactures and markets three products X, Y and Z. All the three products are made from the same set of machines. Production is limited by machine capacity.
From the data given below, indicate priorities for products X, Y and Z with a view to maximising profits:
Illustration 4:
The following particulars are extracted from the records of a company.
Comment on the profitability of each product (both use the same raw material) when:
(i) Total sales potential in units is limited.
(ii) Total sales potential in value is limited.
(iii) Raw Material is in short supply.
(iv) Production capacity (in terms of machine hour) is the limiting factor.
(i) When total sales potential in units is limited, product B will be better as compared to A as its contribution per unit is more by Rs. 17 (i.e. Rs. 87 – Rs. 70).
(ii) When sales potential in value is limited, product B is better as compared to A as its contribution per rupee of sales is more by 9 paise (i.e. 79 paise – 70 paise).
(iii) When raw material is in short supply, product B is better as compared to A as its contribution per kg. of material is more by Rs. 7.75 (i.e. Rs. 21.75 – Rs. 14).
(iv) When production capacity (in terms of machine hours) is the limiting factor, product A is better as compared to B as its contribution per machine hour is more by Rs. 6 (i.e. Rs. 35 – Rs. 29).
Illustration 5:
A company manufactures and market three products A B and C. All the three products are made from the same set of machines. Production is limited by machine capacity.
From data given below indicate priorities for products A, B and C with a view to maximising profits.
In the following year the company faces extreme shortage of raw materials. It is noted that 3 kg., 4 kg. and 5 kg. of raw materials are required to produce one unit of A, B arid C respectively. How would products priorities change?
Managerial Problem # 3. Make or Buy Decision:
A concern can utilise its idle capacity by making component parts instead of buying them from market. In arriving at such a make or buy decision, the price asked by the outside suppliers should be compared with the marginal cost of producing the component parts. If the marginal cost is lower than the price demanded by the outside suppliers, the component parts should be manufactured in the factory itself to utilise unused capacity.
Fixed expenses are not taken in the cost of manufacturing component parts on the assumption that they have been already incurred, the additional cost involved is only variable cost. For example, the total cost of making a component part comes to Rs. 8 consisting of Rs. 6 as variable cost and Rs. 2 as fixed cost. Suppose further an outside supplier is ready to supply the same component part at Rs. 7.
On the basis of total cost method, it appears that it is cheaper to buy the component. But on the basis of marginal cost, the offer of the outside supplier should be rejected because the acceptance will mean that the total cost of the purchased part from the outside supplier will come to Rs. 9 i.e., Rs. 7 (supplier's price) plus Rs. 2 (fixed cost which cannot be saved even if the component is purchased from outside source).
Factors that Influence Make or Buy Decision:
In a make or buy decision the following cost and non-cost factors must be considered specifically:
Cost Factors:
1. Availability of plant facility.
2. Quality and type of item —which affects the production schedule.
3. The space required for the production of item.
4. Any special machinery or equipment required.
5. Any transportation involved due to the location of production i.e. the 'Feeder Point'
6. Cost of acquiring special know how required for the item.
7. As to purchase of raw material the factors like market price, price trend, availability and other must be kept in view.
8. As to labour factors like availability of the required labour.
9. As to overhead expenses, adoption of lease for apportioning them must be taken into consideration including other factors.
10. As to application of the techniques of costing it must be viewed for marginal costing, differential costing or otherwise alike one.
11. In view of above and generally the production of an item will mean an outlay on machines and other facilities including employment of staff which may be permanent and of fixed nature. Thus fixed expenses burden may tend to increase.
So our production is kept at the estimated minimum requirement keeping in view the possible fluctuations in demand and the excess quantity required to be purchased from outside. The effect is that, should demand fall orders from outsiders can be cut down; the cost to be incurred will then be in proportion to the effective demand.
12. Having decided to purchase, it is also to be seen whether the released capacity can be put to more profitable use or not.
Non-Cost Factors:
Among the non-cost factors specifically.
1. In favour of making, the factors like:
(i) Secrecy of company production.
(ii) Idle facility available
(iii) Quality and stability of market supply
(iv) Tax considerations
(v) Desirability of maintaining certain facilities.
2. In favour of buying factors like:
(i) Lack of capital required
(ii) Passing the know how to suppliers or not
(iii) Uneven production of end product
(iv) Wide selection.
3. Generally the following as:
(i) If quality cannot be ensured in our production, the article concerned should be purchased from outside; if outside supplier can not be relied upon in this respect the article should be produced by the firm itself, whatever be the cost.
(ii) In case there are large fluctuations in demand, it is better to purchase from outside, but if the demand is likely to increase substantially, own production may lead to lower costs latter.
(iii) Ensure the capability and reliability of the outside suppliers to supply without any interruption.
In this regard the following factors are to be considered:
(a) The general reputation enjoyed by supplier for reliability
(b) Financial position and reputation
(c) Technical know how and production facilities
(d) His relation with his workmen etc.
(iv) If the business secrecy is to be maintained the manufacturing know how should not be passed on to the supplier, then it is better to produce,
(v) The outside supplier should not be a competitor.
In fact, it is a very crucial decision and both cost and non-cost factors must be weighted well.
Illustration 6:
A manufacturing company finds that while the cost of making a components part is Rs 10, the same is available in the market at Rs. 9 with an assurance of continuous supply. Give your suggestion whether to make or buy this part. Give also your views in case the supplier reduces the price from Rs. 9 to Rs. 8.
The cost information is as follows:
To take a decision on whether to make or buy the component part, fixed expenses being irrelevant cost should not be added to the cost because these will be incurred even if the part is not produced.
Thus, additional cost of the part will be as follows:
The company should produce the part if the part is available in the market at Rs. 9.00 because the production of every part will give to the company a contribution of 50 paise (i.e., Rs. 9.00 – Rs. 8.50).
The company should not manufacture the part if it is available in the market at Rs. 8 because additional cost of producing the part is 50 paise (i.e., Rs. 8.50 – Rs. 8) more than the price at which it is available in the market.
In some cases inspite of lower variable cost of production, there may be an increase in the fixed costs. In such a case increase in fixed cost becomes the relevant cost and should be considered for make or buy decision. It becomes essential to find out the minimum requirement of volume in order to justify the making instead of buying.
This volume can be calculated by the following formula:
Increase in Fixed Costs/Contribution per Unit (i.e. .Purchase Price – Variable Cost of Production)
Illustration 7:
A firm can purchase a separate part from an outside source @ Rs. 11 per unit. There is a proposal that the spare part be produced in the factory itself. For this purpose a machine costing Rs. 1, 00,000 with annual capacity of 20,000 units and a life of 10 years will be required.
A foreman with a monthly salary of Rs. 500 will have to be engaged. Materials required will be Rs. 4.00 per unit and wages Rs. 2.00 per unit. Variable overheads are 150% of direct labour. The firm can easily raise funds @ 10% p.a. Advice the firm whether the proposal should be accepted.
If there is no idle capacity and making of the spare part in the factory involves the loss of other work, the loss of contribution arising from displacement of work should also be considered alongwith variable cost of production.
The loss of contribution is found with reference to key or limiting factor. If the purchase price is higher than the total variable cost of production plus traceable fixed costs plus the loss of contribution of production, it will be more profitable to manufacture.
Illustration 8:
K Ltd. produces a variety of products, each having a number of component parts. B takes 5 hours to process on a machine working to full capacity. B has a selling price of Rs. 50 and a marginal cost of Rs. 30 per unit. 'A-10' component part used for product A, could be made on the same machine in 2 hours for a marginal cost of Rs. 5 per unit.
The supplier's price is Rs. 12.50. Should K Ltd. make or buy 'A-10'? Assume that machine hour is the limiting factor.
Contribution per unit of B = Rs. 50 – Rs. 30 = Rs. 20
Contribution per machine hour = Rs. 20/5 = Rs. 4
If one unit of 'A-10' takes 2 hours, then Rs. 8 (i.e., Rs. 4 x 2) contribution is lost.
... Full cost to make one unit of 'A-10' = Rs. 5 + Rs. 8 = Rs. 13.
This is more than the supplier's price of Rs. 12.50. Hence it would be more profitable to buy 'A- 10' than to make.
Illustration 9:
Ride-well Cogcle Ltd. purchases 20,000 bells per annum from an outside supplier at Rs. 5 each. The management feels that these be manufactured and not purchased. A machine costing Rs. 50,000 will be required to manufacture the item within the factory. The machine has an annual capacity of 30,000 units and life of 5 years.
The following additional information is available:
Material cost per bell will be Rs. 2.00
Labour cost per bell will be Re. 1.00
Variable overheads 100% of labour cost
You are required to advise whether:
(i) the company should continue to purchase the bells from the outside supplier or should make them in the factory ; and
(ii) the company should accept an order to supply 5,000 bells to the market at a selling price of Rs. 4.50 per unit ?
Therefore, the company should manufacture the bells resulting in a saving of Rs. 10,000 annually for 20,000 bells.
(ii) Marginal cost per bell is Rs. 4.00 as shown above. As depreciation of the machine is recovered on 20,000 bells, there will be no additional depreciation on the extra 5,000 bells to be sold in the market. Further the machine has additional capacity too. Therefore, the company is advised to supply 5,000 bells to the market at Rs. 4.50 per unit and make a profit of Re. 0.50 per unit i.e., total profit Rs. 2,500.
Managerial Problem # 4. Selection of a Suitable Product Mix:
When a factory manufactures more than one product, a problem is faced by the management as to which product mix will give the maximum profits. The best product mix is that which yields the maximum contribution. The products which give the maximum contribution are to be retained and their production should be increased.
The products which give comparatively less contribution should be reduced or closed down altogether. The effect of sales mix can also be seen by comparing the P/V ratio and break even point. The new sales mix will be favourable if it increases the P/V ratio and reduces the break even point.
Illustration 10:
Present the following information to show to the management:
(i) The marginal product cost and the contribution per unit.
(ii) The total contribution and profits resulting from each of the following sales mixtures.
(iii) The proposed sales mixes to earn a profit of Rs. 250 and Rs. 300 with total sales of A and B being 300 units.
Sales mixtures :
(a) 100 units of Product A and 200 of B
(b) 150 units of product A and 150 of B
(c) 200 units of product A and 100 of B
Recommend which of the sales mixtures should be adopted.
Illustration 11:
Small Tools Factory has a plant capacity adequate to provide 19,800 hours of machine use. The plant can produce all A type tools or all B type tools or a mixture of the two types.
The following information is relevant:
Market conditions are such that no more than 4,000 A type tools and 3,000 B type tools can be sold in a year. Annual fixed costs are Rs. 9,900.
Compute the product-mix that will maximise the net income to the company and find that maximum net income.
Illustration 12:
A multi product Company has the following costs and output data for the last year.
A comparison of the old situation and proposed change shows that if product Z is replaced by product S it would increase the profit by Rs. 15,000 and break even point will reduce by Rs. 21,760. The change is beneficial and, therefore, product Z may be dropped.
Managerial Problem # 5. Effect of Change in Sales Price:
Management is confronted with the problem of cut in prices of products from time to time on account of competition, expansion programme or government regulations. It is, therefore, necessary to know the effect of a cut in prices of the products. The effect of a cut in selling price per unit will be that contribution per unit will reduce.
Illustration 13:
Hansa Ltd. manufacturing a single product is facing severe competition in selling it at Rs. 50 per unit. The company is operating at 60% level of activity, at which level sales are Rs. 12,00,000. Variable costs are Rs. 30 per unit. Semi-variable costs may be considered as fixed at Rs. 90,000 when output is nil and the variable element is Rs. 250 for each additional 1% level of activity. Fixed costs are Rs. 1,50,000 at the present level of activity, but if a level of activity of 80% or above is reached, these costs are expected to increase by Rs. 50,000.
To cope with the competition, the management of the company is considering a proposal to reduce the selling price by 5%.
You are required to prepare a statement showing the operating profit at levels of activity of 60%, 70%, 80% and assuming that:
(а) the selling price remains at Rs. 50; and
(b) the selling price is reduced by 5%.
Show also the number of units which will be required to be sold to maintain the present profits if the company decided to reduce the selling price of the product by 5%.
Illustration 14:
The revenue account of Goodwill Co. Ltd. has been summarized as shown below:
The licensed capacity of the company is Rs. 80,00,000 but the key factor is sales demand. It is proposed by the management that in order to utilise the existing capacity, the selling price of the product should be reduced by 5%.
You are required to prepare a forecast statement showing the effect of the proposed reduction in selling price after taking into account the following changes in costs:
(i) Sales forecast Rs. 76,00,000 (at reduced prices).
(ii) Direct wages rates and variable overheads are expected to increase by 5%.
(iii) Direct material prices are expected to increase by 2%.
(iv) Fixed overheads will increase by Rs. 80,000.
Managerial Problem # 6. Maintaining a Desired Level of Profits:
Management may be interested in maintaining a desired level of profits. The volume of sales needed to have a desired level of profits can be ascertained by the marginal costing technique as is shown in the following illustration.
Illustration 15:
A company produces and markets industrial containers and packing cases. Due to competition the company purposes to reduce the selling price.
If the present level of profit is to be maintained, indicate the number of units to be sold if the proposed reduction in selling price is:
(a) 5%;
(b) 10%;
(c) 15%.
Managerial Problem # 7. Alternative Methods of Production:
Marginal costing is helpful in comparing the alternative methods of production, i.e., machine work or hand work. The method which gives the greatest contribution (assuming fixed expenses remaining same) is to be adopted keeping, of course, the limiting factor in view. Where, however, fixed expenses change, the decision will be taken on the basis of profit contributed by each.
Illustration 16:
Product X can be produced either by machine A or B. Machine A can produce 100 units of X per hour and machine B 150 units per hour. Total machine hours available during the year are 2,500.
Taking into account the following data determine the profitable method of Manufacture:
Managerial Problem # 8. Cost Indifferent Point:
Sometimes there are two alternatives—one having low variable cost and high fixed cost and the other having high variable cost and low fixed cost. The cost indifferent point has to be determined by linking the incremental fixed overhead by the savings in variable costs.
At indifferent point the total cost of the two alternatives will be the same. In case of selection of machine, this point will be helpful in calculating the levels of sales at which both machines earn equal profits and the range of sales at which one is more profitable than the other.
This will be more clear from the following illustration.
Illustration 17:
(Selection of Machine). X Limited has been offered a choice to buy a machine between 'A' and 'B'. You are required to compute:
(а) Break-even point for each of the machines.
(b) The level of Sales at which both machines earn equal profits.
(c) The range of Sales at which one is more profitable than the other.
The relevant data is as given below:
(b) As the selling price of the products produced A and B are equal, the machines will earn equal profit when total cost of operation of both machines are the same.
If x be the output when total cost of the machines are the same, we have total cost of machine 'A' = 4x + Rs. 30,000
and machine 'B' = 6x + Rs. 16,000
4x + Rs. 3,000 = 6x + Rs.16,000
2x = 14,000
x = 7,000
At a production level of 7,000 units the profits made by the machines 'A' and 'B' are equal.
(c) The breakeven point of 'A' is at 5,000 units compared to that of 4,000 units in case of B and at a production level of 7,000 units they earn equal profit. It is quite clear that the profit earning capacity for machine 'B' is more in the range of 4,000 to 6,999 units as it starts earning profit at lower point. But 'A' will earn more beyond 7,000 units as it has a higher P/V ratio which will enable it to earn more incremental contribution on the increasing sales.
Illustration 18:
S manufactures a component that it sells for Rs. 8 per unit. The company is contemplating an increase in selling price to Rs. 9 per unit. If selling price is increased, the volume of sales is expected to decline.
Company is willing to increase the price if resulting net income is greater than Rs. 30,000, which company earns presently as follows:
Managerial Problem # 9. Diversification of Products:
Sometimes it becomes necessary for a concern to introduce a new product to the existing product or products in order to utilise the idle capacity or to capture a new market or for other purposes. The new product must be profitable.
In order to decide about the profitability of the new product, it is assumed that the manufacture of the new product will not increase fixed costs of the concern and if the price realised from the sale of such product is more than its variable cost of production it is worth trying.
If this data is presented under absorption costing method, the decision will be wrong. But if with the introduction of new product there is an increase in the fixed costs, then such specific increase in fixed costs must be deducted from the contribution for making any decision. General fixed costs will, however, be charged to the old product/products.
Illustration 19:
Evenheel Ltd., manufactures and sells a single product X whose selling price is Rs. 40 per unit and the variable cost is Rs. 16 per unit.
(а) If the fixed costs for this year are Rs. 4,80,000 and the annual sales are at 60% margin of safety, calculate the rate of net return on sale, assuming an income-tax level of 40%.
(b) For the next year, it is proposed to add another product line Y whose selling price would be Rs. 50 per unit and the variable cost Rs. 10 per unit. The total fixed costs are estimated at Rs. 6,66,600. The sales mix of X, Y would be 7 : 3. At what level of sales next year, would Evenheel Ltd., break even? Give separately for both X and Y the break even sales in rupees and quantities.
Managerial Problem # 10. Closing Down or Suspending Activities:
Sometimes it becomes necessary for a firm to temporarily suspend or close the activities of a particular product, department or factory as a whole due to trade recession. The decision to close down or suspend its activities will depend on whether products are making a contribution towards fixed costs or not.
If the products are making a contribution towards fixed costs, it is preferable not to close business or suspend its activities to minimise the losses. If the business is closed down there may be certain fixed costs which could be avoided but there will be certain expenses which will have to be incurred at the time of closing the operation like redundancy payments, necessary maintenance of plant or overhauling of plant on reopening, training of personnel etc. Such costs are associated with closing down of the business and must be taken into consideration before taking any decision.
Fixed costs may be general or specific. General fixed costs may or may not remain constant while specific costs will be directly affected by the closing down of the operation. To conclude, if general fixed costs are likely to come down in the event of closure or suspension of activities, the excess of contribution over specific fixed costs will have to be compared with reduction in general fixed cost. If the former exceeds the latter it is profitable to continue the activities and close down or suspend activities if the latter exceeds the former.
In addition to cost consideration, there may be some non-cost considerations which may weigh in taking the decision to close down or suspend its activities or not.
The following non-cost considerations are relevant in this respect:
(i) Once the business is closed down, competitors may establish their products and our business may be lost. It may be difficult to recapture the lost market again; heavy advertisement charges may have to be incurred to recapture the business again.
(ii) Fear of retrenchment of workers. If workers are discharged it may be difficult to get experienced and skilled workers again at the restart of the business.
(iii) Plant may become obsolete with the closure of the business and heavy capital expenditure may have to be incurred on restart of the business.
(iv) Reputation of the firm may suffer if some activities are closed down or suspended.
(v) Temporary closing down or suspending activities may not be desirable if the relationship with the suppliers is adversely affected.
(vi) Fear of non-collection of dues from customers in case of close of business may not go in favour of closure of business.
Illustration 20:
The annual flexible budget of a company is as follows:
Owing to trade difficulties the company is operating at 50% capacity. Selling prices have had to be lowered to what the directors maintain is an uneconomic level and they are considering whether or not their single factory should be closed down until the trade recession has passed.
A market research consultant has advised that in about twelve months' time there is every indication that sales will increase to about 75% of normal capacity and that the revenue to be produced from sales in the second year will amount to Rs. 90,000. The present revenue from sales at 50% capacity would amount to only Rs. 49,500 for a complete year.
If the directors decide to close down the factory for the year, it is estimated that:
(a) The present fixed costs would be reduced to Rs. 11,000 a year.
(b) Closing down costs (redundancy payments etc.) would amount to Rs. 7,500.
(c) Necessary maintenance of plant would cost Rs. 1,000 p.a.
(d) On reopening the factory the cost of overhauling plant, training and engagement of new personnel would amount to Rs. 4,000.
Prepare a statement for the directors presenting in such a way as to indicate whether or not it is desirable to close the factory.
From the above it is clear that the amount of loss can be reduced by Rs. 13,500 (i.e. Rs. 23,500 — Rs. 10,000) if the factory is continued to operate at 50% capacity. There will be profit of Rs. 10,250 in the second year, so closing down of factory is undesirable.
Managerial Problem # 11. Alternative Course of Action:
When deciding between alternative courses of action, it shall be kept in mind that whatever course of action is adopted, certain fixed expenses will remain unaffected. The criterion, therefore, which weighs is the effect of alternative course of action upon the marginal (i.e., variable) costs in relation to the revenue obtained. The course of action which yields the greatest contribution is the most profitable to be followed by the management.
Illustration 21:
The cost per unit of the three products, A, B and C of a concern is as follows:
Production arrangements are such that if one product is given up, the production of the others can be raised by 50%. The directors propose that C should be given up because the contribution in that case is the lowest. Do you agree?
From the three production arrangements we see that the profit is the maximum when product B is given up. Therefore, we do not agree with the directors that C should be given up and recommend that product B should be given up in order to have the maximum profit.


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Rockfall Protection, Retaining Structures, Soil Reinforcement and Erosion Control for Railways
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Maccaferri manufactures, designs and supplies gabion retaining walls and Reno mattress erosion control systems for rivers and channels. The company also provides erosion protection solutions, as well as a wide range of geogrids for strengthened earthworks, soil reinforcement and slope stabilisation.
Recent additions also include rockfall protection and debris flow mitigation systems, as well as asphalt pavement reinforcement grids, textile and meshes.
Maccaferri offers in-depth technical and design support to provide real-world solutions for projects. The company's specialist support services help clients reduce project risks, costs and time with value-engineered, safe and effective solutions.
Avalanche, debris flows, and rockfall protection systems for railways
Maccaferri offers numerous solutions to mitigate risks from natural hazards.
The company offer a wide range of rockfall protection mesh types, from lighter hexagonal mesh for simple drapery, to Maccaferri's high-tensile strength mesh Steelgrid for demanding pinned drapery and surface stabilisation. These meshes are often used with soil nailing.Maccaferri also offers high-energy absorption (HEA) panels, ultra-strong steel cable panels, and ring nets for rock containment on cliff and rock faces.
The company's rockfall catch fences (rockfall barriers) are used to intercept falling rocks and prevent them from impacting rail users. They are available with energy absorption capacities from 100kJ to 8,500kJ. Maccaferri barriers offer the lowest deflection during impact. They can be installed closer to the track, making installation simpler and more cost-effective.
Debris flow barriers are also available to contain even small landslips and snow slides, which can impact timetables and rail safety.
Soil-nailing is an excellent solution for strengthening unstable slopes and railway embankments, while the company' MacMat R can be used for surface stabilisation. The steel-reinforced 3D geomat spans between nail-heads and limits erosion, and the integral geomat provides an ideal substrate for vegetation re-establishment.
Maccaferri's MacRO Studio Rockfall software allows engineers to design solutions for rockfall mitigation and surface stabilisation problems.
Geogrids for reinforced walls and soil slopes
Maccaferri geogrids are planted in soils to reinforce them, allowing them to stand at steeper angles and accommodate greater loads. The company supplies a wide range of geogrid soil reinforcement types and strengths to suit a variety of soil conditions. This maximises the opportunity to re-use site-won material as structural backfill, and create a more sustainable solution.
Maccaferri offers different facing types for vertical walls and soil slopes, and to suit the appearance required.
The company's Terramesh and Green Terramesh soil reinforcement systems have a gabion fascia and green vegetating fascia respectively. The geogrid is integrated with the fascia, and assembly components are factory fitted, increasing installation speed compared to other systems.
Paragrid, Paralink, Paraweb and MacGrid soil reinforcement geogrids have the best long-term design strength reduction factors on the market, a testament to their quality and 'tried and tested' performance.
These geosynthetic reinforcements are used within our MacRES vertical concrete panel walls system, which produces vertical, concrete-faced, reinforced soil structures ideal for urban areas or rail-flyovers.
Designers can use our MacSTARS software to design reinforced soil slopes and walls.
Flexible and durable gabion retaining walls for rail applications
Maccaferri gabion retaining structures have been used for earth retention purposes on a multitude of railway applications.
The gabions are long-lasting, simple-to-install, and have been certified by numerous authorities worldwide, including Brasil, France, Italy, South Africa and the UK. The structures are flexible and can accommodate differential settlement easily without being damaged; ideal for seismic areas or soft ground.
The company's range of gabion types include Strong Face units and even Cubiroc pre-filled gabions, which are ready to be placed into projects immediately. Cubiroc units are ideal for fast-moving rail projects, such as installing a retaining wall overnight.
Maccaferri gabion walls also have a lower carbon footprint than traditional concrete retaining walls.
Using the company's GawacWIN design software, engineers can quickly design gabion retaining walls.
Hydraulic works, erosion control and vegetation
Maccaferri offers erosion control solutions tailored to the erosion forces involved and the surface to be protected. The company also supplies Reno mattresses filled with stones for heavy hydraulic flows, MacMat R and MacMat non-degradable high-performance geomats (TRMs) for medium erosion forces, and Biomac, coir and natural fibre biodegradable geomats for light erosion control.
Engineers can quickly design hydraulic erosion protection for water courses using Maccaferri's MacRA software.
Basal platforms and reinforcement for rail embankments
The company's Paralink geosynthetic geogrid strengthens basal platforms against forces up to 1350kN/m.
Paralink geogrids absorb, spread, and dissipate applied loads vertically downwards into the ground, or into the piles. Furthermore, by enhancing the soil's ability to 'span' or 'arch', a high-strength geosynthetic can increase pile spacing.
Soil stabilisation for track-bed platforms
MacGrid EG geogrids can be used to stabilise soft ground, provide access over difficult areas, or reduce the thickness of aggregate layers in track-bed construction.
The geogrids interlock with granular layers, reinforcing them and improving the efficiency of track-beds.
Contact Details
Officine Maccaferri SpA - Global Headquarters
Via J.F. Kennedy 10
40069 Zola Predosa – Bologna
+39 051 6436000
Maccaferri Transportation Infrastructure
Available White Papers
Rockfall Protection and Snow Barriers With over 60 years' experience in rockfall protection systems and natural hazard mitigation, Maccaferri offers a wide range of systems to stabilise rock faces, soil slopes and snow masses, reducing risks to people, buildings and infrastructure.
Global Mining Solutions Founded in 1879, Maccaferri is a leader in innovative and sustainable solutions to overcome environmental, geotechnical and hydraulic erosion problems.
Hydraulic Works Maccaferri's specialist knowledge and comprehensive product range, we offer clients a graded, logical range of hydraulic erosion protection techniques from soil bioengineering solutions through to robust high-energy capacity structures.
Soil Stabilisation and Pavements Whether constructing a gravel forestry track over soft soil or resurfacging a multi-lane highway, Maccaferri has the technical knowledge and wide product range to provide solutions for the rigourous demands of today's roads.