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MANCHESTER, England -- There is a story about Margaret Thatcher, which is probably apocryphal, but speaks volumes about the strength of Britain's first female prime minister, who died Monday at age 87.
Following her election in 1979, the story goes that Thatcher took her all-male cabinet out to dinner. The waiter asked what she would like. "I'll have the beef," she said. The waiter asked, "What about the vegetables?" "They'll have the same," Thatcher replied.
"Thatcher Saved Britain," read a headline in the Daily Telegraph. No, Thatcher inspired citizens of Great Britain to have less faith in government and more self-reliance, so that they could save themselves. Ronald Reagan tried to do the same for America.
In 1979, Britain and the United States were in a funk. President Jimmy Carter blamed Americans for what he called their "malaise." Thatcher reminded Britain of its glorious past and the inherent strength of the British people. She didn't believe Britons had to accept their lot.
Thatcher began dismantling the welfare state, breaking up state monopolies and confronting powerful unions. Reagan shared her views and the two of them sought to restore their people's faith in individualism, turning them away from the false and failed doctrine of government as savior.
I met Thatcher on several occasions and saw her "live" many times, including during a debate in the House of Commons in the early '80s with Labour's Michael Foot. Thatcher annihilated him on every point to the delight of her Conservative Party colleagues and many in the galleries.
Her longtime director of press and communications, Harvey Thomas, emailed from London. He said he once suggested she might soften her tough image by allowing him to "(make) her a little more 'domestic,' (emphasizing) family and (her) gentler side. She turned to me and said, 'Oh, we can't do that, dear. If the Russians start to think I am too feminine, it could lead to World War III.'"
After Thatcher left office, we shared the stage at an event in Phoenix, which was organized by former presidential candidate Steve Forbes, the publisher of Forbes magazine. After her address she walked into a reception area and sat down at a table by herself. Everyone seemed afraid to approach her. I sat down next to her and we had a nice chat about world events while the hesitant crowd gathered around to listen.
She transcended identity politics. Her ideas, not her gender, were supreme.
British Prime Minister David Cameron called her "a lion-hearted" leader who served the British people "with all she had." And she had a lot.
She also shared Reagan's gift for turning a phrase. Among many reprinted in the British press: "For me, pragmatism is not enough. Nor is that fashionable word 'consensus.' . . . To me consensus seems to be the process of abandoning all beliefs, principles, values and policies in search of something in which no one believes, but to which no one objects..."
In a 1981 speech she said, "My policies are based not on some economics theory, but on things I and millions like me were brought up with: an honest day's work for an honest day's pay; live within your means; put by a nest egg for a rainy day; pay your bills on time; support the police."
True to her principles to the end, she requested that she not be given a state funeral with military flyovers. "It would be a waste of money," she reportedly said. Instead, Thatcher's ceremonial funeral will be conducted at St. Paul's Cathedral with Queen Elizabeth breaking protocol by attending her first funeral for a prime minister since Winston Churchill's nearly 50 years ago.
UK Telegraph columnist Allison Pearson wrote: "Lady Thatcher wasn't normal, but then neither was her achievement. She sacrificed family life and got the job done."
Not a bad epitaph.

subset: commoncrawl


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'De la Luna al Fuego' ('from the Moon to Fire') festival
This event aims to celebrate two festivals: the Corpus Christi and San Juan.
This event takes place within the city walls and recreates the atmosphere of the street markets in the 16th-18th centuries, and is held to coincide with traditional celebrations such as the Corpus Christi and the typical festivity known as the 'mojá de varas' (dipping poles in water) on the night of San Juan. The moon recalls the historic origins of the feast of the Corpus, which since the 16th century has been a highly spectacular event in Zafra, and is today celebrated with carpets of flowers strewn throughout the streets. In contrast, fire is the traditional symbol of the festivities of San Juan (the day of the summer solstice). Since 1935, the town has also been the site of the Fair of San Juan (the oldest fair in the city).
'De la Luna al Fuego' ('from the Moon to Fire') festival
Zafra, Badajoz (Extremadura)
* To be confirmed


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Water SA
On-line version ISSN 1816-7950
Print version ISSN 0378-4738
Water SA vol.40 n.2 Pretoria Apr. 2014
Use of the FAO AquaCrop model in developing sowing guidelines for rainfed maize in Zimbabwe
Teddious MhizhaI; Sam GeertsII; Eline VanuytrechtII; Amos MakarauIII; Dirk RaesII
IDepartment of Physics, University of Zimbabwe, Mount Pleasant Drive, Harare, Zimbabwe
IIDivision of Soil and Water Management, K.U. Leuven University, Celestijnenlaan 200E, 3001 Leuven, Belgium
IIIMeteorological Services Department, P.O. Box BE150, Belvedere, Harare, Zimbabwe
This paper presents a procedure in which the water-driven water productivity model AquaCrop was fine-tuned and validated for maize for the local conditions in Zimbabwe and then applied to develop sowing management options for decision support. Data from experiments of 2 seasons in Harare and from 5 other sites around Zimbabwe were used for the local calibration and validation of AquaCrop. Model parameters such as the reference harvest index (HIo); the canopy growth coefficient (CGC); early canopy decline and normalised biomass water productivity (WPb*) were adjusted during model calibration. Model performance was satisfactory after calibration with a Nash-Sutcliffe model efficiency parameter (EF = 0.81), RMSE = 15% and R2 = 0.86 upon validation. To develop sowing guidelines, historical climate series from 13 meteorological stations around Zimbabwe were used to simulate maize yield for 6 consecutive sowing dates determined according to criteria applicable in Zimbabwe. Three varieties and typical shallow and deep soil types were considered in the simulation scenarios. The simulated yield was analysed by an optimisation procedure to select the optimum sowing time that maximised long-term mean yield. Results showed that highest yields depended on the climate of the site (rainfall availability), variety (length of growing cycle) and soil depth (soil water storage capacity). The late variety gave higher mean yields for all sowing dates in the maize belt. Staggered sowing is recommended as a way of combating the effects of rainfall variability and as an answer to labour constraints.
Keywords: biomass water productivity, AquaCrop, maize sowing dates, crop modelling
The global population is projected to continue on an upward trend (FAO, 1996; Mpande and Tawanda, 1998), more so in sub-Saharan Africa where food deficit is already a significant challenge (Pinstrup-Andersen et al., 1999). Competing demands for both freshwater and land use, such as from industry and municipalities, as well as environmental problems such as pollution, will limit future extension of both freshwater for irrigation and the cultivated land area. With limited room for expansion of both agricultural land and the irrigated portion of the arable land (Rockström and Baron, 2007), additional food production will have to come from intensification of production in rainfed farming systems. Rockström et al. (2003) showed that it is possible to at least double rainfed staple food production by producing more 'crop per drop' of rainwater. It is therefore necessary to explore ways of increasing water use efficiency in rainfed agricultural systems.
Climate variability has been identified as the major constraint to agricultural productivity in southern Africa, and hence reducing the risk associated with climate variability has a high potential for increasing productivity in Zimbabwe (Phillips et al., 1998). Despite commanding a large share of the annual grain output, rainfed production of maize in Zimbabwe is largely unstable (Mhizha, 2010). The fluctuations echo in the availability of food in the country, often with a telling effect on the economy as resources are channelled towards securing food to avert starvation, resources which would have otherwise gone to other economic sectors for development. The instability in rainfed production is largely credited to availability of rainwater, which itself shows wide variability in both total amounts and seasonal quality (Rockström and Barron, 2007). Rainfall variability, especially the less well defined onset of the rainy season has increased in the recent past possibly linked to climate change. The start and end of the rainy season defines the length of the rainy season which strongly determines the success or failure of rainfed crops. In addition, the quality of the growing season, as indicated by the length and severity of within-season dry spells, will also influence the yield gap and can often cause total crop failure (Geerts et al., 2006; Phillips et al., 1998). While agricultural water management has largely succeeded in maximising rainfall infiltration through soil and water conservation, the challenge of how to cope with dry-spells, short periods of water stress during crop growth, remains largely unsolved (Fox and Rockström, 2003). Because false planting dates requiring replanting are increasingly common in Zimbabwe (Raes et al., 2004), there is an increasing demand for sowing strategies that minimise risk of total crop failure, such as staggered planting.
Judicious management decision making, such as planting dates and fertiliser application rates, can contribute to increased yields under rainfed conditions. Management decision support for rainfed farming systems is a challenge for resource-poor communities such as subsistence farmers in Sub-Saharan Africa. Optimum management practices, such as planting date, cultivar selection, fertilisation, or water and pesticide application, can be assessed through validated models for making seasonal or within-season decisions (Boote et al., 1996). Simulation experiments can be of significant use in exploring different management options for decision support in cases where field experiments are scarce. Accurate modelling of crop response to water plays an important role in development of guidelines for improving water use efficiency in agriculture (Geerts et al., 2009a). There are many models that simulate the growth and development of maize, such as CERES-Maize (Jones et al., 1987) and Hybrid-Maize (Yang et al., 2004), but most are often applicable only to the fields for which they are calibrated and require a number of parameters next to impossible to collect in rainfed field conditions. AquaCrop, on the other hand, although based on complex crop physiological processes, uses a relatively small number of explicit and mostly intuitive parameters and attempts to balance simplicity, accuracy and robustness (Steduto et al., 2009; Raes et al., 2009a). AquaCrop can in this regard be considered suitable for application in resource-challenged communities where extensive input data may not be available.
AquaCrop is a crop water productivity model (Steduto et al., 2009; Raes et al., 2009a) broadly tested for simulating maize yield response to water (Hsiao et al., 2009; Heng et al., 2009). The model was validated for a wide range of environmental conditions, namely, extraordinarily high evapotran-spiration and wind speed in Bushland, Texas, rainy weather and sandy soil in Gainesville, Florida, and semiarid conditions in Zaragoza, Spain (Heng et al., 2009). Many papers have reported the application of AquaCrop in simulating various management scenarios for many crops including maize (Hsiao et al., 2009, Heng et al., 2009, Stricevic et al., 2011), quinoa (Geerts et al., 2009a), cotton (Garcia-Vila et al., 2009), sunflower (Todorovic et al., 2009, Stricevic et al., 2011) and sugar beet (Stricevic et al., 2011) with success. Against such background, Aquacrop is expected to be potentially suitable for simulating maize yield response to water availability in the semi-arid conditions of Zimbabwe, although reported studies are lacking. To account for the unpredictability of rainfall in the season, farmers often aim at minimising risk, which often means settling for low inputs and low but stable yields (Phillips et al., 1998). One possible strategy is to sow several varieties of a single crop on several planting dates at the start of the rainy season. The varieties differ in their length of the growing cycle and their potential yield. Depending on the length of the rainy season, the total amount of rainfall received during the season and the frequency, length and period of dry spells, it is expected that at least one variety on one of the planting dates will give good yields. As such the farmer is guaranteed an income each year. However the guidelines for this sowing strategy have not been clearly laid down in literature for Zimbabwe's agro-ecological zones. Also the sowing strategy needs to be evaluated for effectiveness in reducing risk of crop failure.
Raes et al. (2004) evaluated the performance of 3 criteria that can be used to determine first planting dates for maize in Zimbabwe. The study concluded that the 3 criteria had different failure rates of 1 in 2 years, 2 in 5 years and 1 in 4 years, depending on the severity of the criterion. The analysis was limited to the establishment stage (first 30 days after sowing) and the rest of the growing season was not assessed. The aim of this paper is to apply AquaCrop to develop decision support guidelines for sowing maize under rainfed conditions for the semi-arid tropical climate of Zimbabwe. A combination of field trials and model simulation experiments were used in this study to analyse response of maize yield to long-term variation in rainfall at climate stations around Zimbabwe. The results are then applied to guide a sowing strategy that minimises year to year variation in rainfed maize yields of smallholder farmers. Field experiments at a research station in Harare and 5 other locations in areas around Zimbabwe where maize is commonly grown provided data for model evaluation. The first part of the paper presents the local calibration of AquaCrop for maize by adjusting for a lower soil fertility level. The second part presents the application of the validated AquaCrop to simulate maize yield response to a long climate data series in order to develop optimised staggered sowing guidelines for rainfed maize in Zimbabwe.
Study area
The study was conducted in the so-called maize belt of Zimbabwe and its surroundings (Fig. 1). Vincent and Thomas (1960) divided Zimbabwe into 5 main natural regions primarily on the basis of rainfall, but also considering other factors such as soil type, altitude and land use. Rainfall patterns and crop production progressively deteriorate from Region I to V. Annual mean rainfall is highest in Natural Region I which covers approximately 2% of the land area. It is a specialised and diversified farming region with plantation forestry, fruit and intensive livestock production. Natural Region II, covering 15% of the land area, receives lower rainfall than Region I, but is nevertheless suitable for intensive farming based on crop or livestock production. Rainfed maize production has the highest potential in Regions IIa and IIb (Fig. 1) (Eicher, 1995; Burt et al., 2001; Philips et al., 2002) because rainfall in Regions III to V is too low and erratic for the reliable production of rainfed maize. Natural Region II is traditionally referred to as the maize belt of Zimbabwe.
Field trials and observations
The data for calibration and validation of AquaCrop were obtained from field experiments conducted at 6 locations in 5 seasons (Table 1).
Intensive measurements for model calibration data collection were carried out at Thornpark (Table 1) during the 2006 to 2007 and 2007 to 2008 farming seasons, while the other sites were extensively monitored to give datasets for the validation process (Table 2). At Thornpark, land preparation each year was by ploughing and harrowing in October before the first rains. All sowing was wet sowing after rainfall, except in 2006 when supplementary irrigation was applied at sowing to allow for very early sowing before the first rains. All plots measured 10 x 10 m and plants were spaced 90 cm between rows and 30 cm in row. One seed was sown per sowing station giving a target plant density of about 37 000 plants/ha. At sowing, a basal fertiliser of compound D (nitrogen; phosphorus; potassium, (NPK): 7%; 16%; 5%, respectively) was applied at a rate of 300 kg/ha. Basal dressing was applied in the sowing holes and covered together with the seed. Top dressing was applied at 5 weeks using ammonium nitrate (34.5% N) granules at a rate of 300 kg/ha (about 104 kg/ha N). This application rate, although it is recommended for the rainfed conditions in Zimbabwe, is rather low when compared to the optimal rate of 200 kg/ha N recommended by FAO (2010). Spot application without covering with soil was used for the top dressing. Management at the other sites is considered similar to Thornpark although no detailed records are available.
The parameters observed for the trials at Thornpark farm included canopy cover (CC), soil water content (SWC), maximum effective rooting depth (Zr) above ground biomass (B) and grain yield (Y). Weather data, including daily rainfall, were observed on site by means of an automated weather station. Data collected at the other locations consisted of grain yield, daily rainfall and reference evapotranspiration (ETo) estimated from weather data of the weather station nearest the trial site via the FAO Penman-Monteith equation (Allen et al., 1998).
Canopy cover (CC) was estimated using the meter-stick method (Armbrust, 1990), in which the proportion of the ground shaded by the crop canopy under clear skies and within 2 hours of solar noon (Local time = GMT + 2 h) is expressed as CC in percentage. The restriction of time was imposed to reduce bias caused by effects of the solar elevation angle on the size of the shaded area.
Soil water content (SWC) was measured fortnightly at 10 cm depth intervals up to 1 m gravimetrically. Bulk densities were determined by using an undisturbed soil sampling kit consisting an auger and cylindrical cores of known volume (100 cm3), then weighing the soil after oven drying at 105°C for 24 h. Observed root zone water content was calculated by considering measured SWC for the soil depth equal to the effective rooting depth. The estimated maximum effective rooting depth (Zr ) was used for this purpose.
Maximum effective rooting depth (Zr) was estimated by visual inspection of 1.5 m deep pits dug in the plots to expose the roots at physiological maturity. Washing of the profile with water facilitated clarity in identifying the roots and the lowest level where roots of the maize crop could be observed was considered the maximum effective rooting depth. Soil water retention characteristics were derived from a soil baseline study at the Thornpark site and literature (Mhizha, 2010).
Above-ground biomass (B) samples were collected by cutting the maize at a stubble height of 5 cm and oven-drying at 80°C for 48 h. The sampling was at 2-weekly intervals from approximately the end of the establishment phase of the crop (30 days after sowing) to biological maturity.
At harvest, the grain yield (Y) was weighed and its moisture content measured by a crop moisture meter. The fresh weight was standardised by calculating the equivalent mass at standard moisture content of 12.5% using Eq. (1).
mstd is the grain mass (kg) at 12.5% moisture content
m is the measured mass of grain (kg) at M% moisture content wet basis at harvest.
The harvest index was calculated as the ratio of standardised grain yield to the dry above-ground biomass at harvest.
The crop characteristic variables monitored and the sites of their observation are described in Table 2. The data fields for calibration and validation are identified in this table.
For detailed description of AquaCrop parameterisation refer to Raes et al. (2009a), Raes et al. (2009b) and Steduto et al. (2009). The AquaCrop input parameters for maize were reported by Hsiao et al. (2009) and validated by Heng et al. (2009) to be either conservative or cultivar specific. Conservative crop parameters are considered constant for all maize cultivars (Hsiao et al., 2009; Heng et al., 2009) while cultivar-specific parameters, on the other hand, may need fine tuning to be applicable to specific local cultivar characteristics. The conservative crop parameters describe the crop development, transpiration, biomass accumulation and grain yield production for optimal environmental conditions. These processes are modified when water stress exists, in which case the modelled processes are adjusted in proportion with the level of stress through the various water stress coefficients (Raes et al., 2009b).
In AquaCrop the effect of soil fertility needs to be calibrated by means of a set of soil fertility stress coefficients (Raes et al., 2009b). The calibration corrects for the effect of soil fertility stress on: (i) canopy development (CGC), (ii) rate of canopy decline once maximum canopy cover (CCx) is reached (early canopy decline), (iii) biomass water productivity (WPb) and (iv) reference harvest index (HIo). As the fertilisation level was below optimum, some of the conservative crop parameters (Table 3) were adjusted for the local 'near optimal' soil fertility levels of the field trials. The AquaCrop model parameters calibrated for this study are presented in Table 3.
The calibration procedure followed (Mhizha, 2010) involved adjusting model parameters for canopy development (CGC), early canopy decline, biomass accumulation (WPb) and grain yield production (HIo) using measured data on canopy cover (CC), biomass and grain yield respectively. The procedure consisted in using specific observed variables as the reference variables (Table 4) in the calibration and adjusting only those parameters (degrees of freedom) that are known to influence the reference variables the most.
The match between simulated and observed reference variables (Table 4) was assessed using goodness of fit tests comprising: the Nash-Sutcliffe model efficiency coefficient (EF) (Nash and Sutcliffe, 1970; Wglarczyk, 1998; Krause et al., 2005) that was evaluated to assess the predictive power of the model; the root mean square error (RMSE) and the coefficient of determination (R2) (Loague and Green, 1991) that were evaluated to assess the error in the model estimates and the correlation between modelled and observed variables, respectively. RMSE was minimised while EF and R2 were maximised in the termination criteria of the calibration. In the validation process, separate data fields (Table 2) were used as observed reference variables in similar goodness of fit tests without any further changes to the calibrated parameters.
Development of sowing guidelines
This section describes how AquaCrop was applied to simulate the response of maize yield to scenarios of sowing date and variety over a long series of climate data at 13 stations in Zimbabwe. The yield response data were used to develop guidelines for sowing maize under rainfed conditions in the study areas.
Climate data
Historical climate data for the study area (Table 5) were used as the input for the climate environment in AquaCrop. Each climate file comprised of daily rainfall data, daily (or monthly) maximum and minimum air temperatures and daily (or monthly) reference evapotranspiration (ET0) data. The default CO2 file within AquaCrop was used to adjust the normalised biomass water productivity (WPb*) to the CO2 concentration of the simulated year (Raes et al., 2009a).
Crop and soil characteristics
In addition to climate input, 3 varieties differing only in growth cycle length (Table 6), with the rest of the crop parameters as calibrated in the previous section, were considered for each site. The soil type at each site (Table 5) was considered for the respective sites. Typical shallow (0.6 m) and deep (1.2 m) soil depths were considered making 2 soil files for each site. Overall there were 3 crop files and 2 soil files for each climate site.
Simulated sowing scenarios
The first sowing date can be defined as the first rainfall event capable of supporting germination (Keatinge et al., 1995). In this study the first sowing date of the season was defined according to the DEPTH criterion, (Raes et al, 2004). According to the DEPTH criterion, first sowing date in Zimbabwe is defined as the first day after 1 October on which the occurrence of 40 mm of rainfall within a 4-day period is observed (Raes et al., 2004). After the first sowing date, 5 other subsequent sowing dates in the same season were determined using a less severe criterion, AREX (Agricultural Research and Extension) (Raes et al., 2004) which defines a sowing date as the occurrence of 25 mm in 7 days after the initial search date, the first sowing date in this case. The AREX criterion replaced the DEPTH criterion for subsequent sowing date determination for the following reasons. First, the DEPTH criterion is more difficult to meet hence fewer sowing dates, often less than 5 in a season could be determined using it. Second, the rather severe conditions of the DEPTH criterion were explained in Raes et al. (2004) as necessary to bring a dry topsoil at wilting point to field capacity and sustain germination and survival of the seedling until the next rains are received. Since the first sowing date would indicate the start of the growing period in 3 out of 4 years, the soil was no longer expected to be at wilting point and so a less strict AREX criterion (25 mm in 7 days) was considered appropriate.
All simulation runs were started on the first day of October in each season, before the start of the rainfall season and assuming a bare soil. All of the soil's readily available water (RAW) would have been lost by this time, 4 months after the latest normal cessation date of the previous rainfall season, estimated to be the end of May (Mhizha, 2010). Therefore all simulation runs started before sowing with a uniform soil water content of θWP. Overall, for each of the 13 climate stations, 18 treatments (3 varieties and 6 sowing dates) were simulated for each climate year. With an average of 28 climate years per station and with 2 soil depths considered at each station, a total of 13 104 treatment simulations were run for 13 climate stations in and around the maize belt of Zimbabwe.
Optimisation analysis of the simulated yield was applied to obtain the algorithms that allocate the best acreage proportions to the 18 sowing treatments for maximum total yield and maximum yield stability over the 28 years. Microsoft Excel's Solver tool was used for the optimisation analysis. Coefficients or weighting factors for each sowing date and variety treatment were optimised such that 1, 2 or 3 of the 18 sowing options were selected as an optimised sowing strategy. In this way, optimised sowing strategies were selected for zero, 2-stage or 3-stage staggered sowing. The objective of the optimisation procedure was to maximise the average and minimise the standard deviation of the simulated grain yield over the 28 years analysed.
The Microsoft Excel solver is a general-purpose spreadsheet optimisation modelling system in use since 1991 (Fylstra et al., 1998). Solver allows for a choice to be made between the simplex algorithm for linear models and the non-linear generalised reduced gradient (GRG2) code. The non-linear GRG2 model was used in this analysis. Since steepest gradient methods used by Solver are local optimisers, the initial starting points of the search process were changed in order to capture a more global optimal solution of the parameter estimation.
For the purpose of developing the optimisation objective function, a total yield term YT was defined as the weighted summation of the grain yield simulated for each of the 18 sowing options (3 varieties by 6 sowing dates):
Yis is the simulated grain yield of the ith variety sown on the
sth sowing date
ais is the weighting factor assigned to the ith variety sown on the sth sowing date by the optimisation procedure
The weighting factors (ais) given to each yield term in the summation were aimed at giving more weight to more desirable treatments and less (even none) to undesirable treatments that are not likely to add value (increase mean and decrease standard deviation) to the average yield. Therefore these weighting factors formed the changing cells of the optimisation procedure with the target cell being the mean of YT averaged over the 28 years. The target cell was maximised for highest stable yields. In addition, by making the target cell the standard deviation of YT over the same period of 28 years, and then minimising the target cell, optimised sowing options were selected that minimised year-to-year yield variation (maximises yield stability). By means of constraints, the number of options selected in the optimisation could be restricted to 1, 2, or 3. This allowed for optimisation for staggered sowing strategies with 1, 2 or 3 stages of sowing. For instance by applying the constraint (Eq. (3)) and by making another constraint such that the number of changing cells ais with non-zero values is equal to 1, only one ais weighting factor is selected that allocates 100% of the land to 1 of the 18 sowing options resulting in the selection of a non-staggered sowing strategy:
The optimisation procedure was applied to each climate station and soil depth so that sowing strategies could be selected for each station and soil type. Grouping stations from the same region (maize belt, border and outside of the maize belt), modal sowing strategies were selected for generalised application to the whole region.
Field observations
Observed weather data are presented in Table 7. Irrigation was applied to 1 treatment at Thornpark in the 2006/07 season to sustain the crop which was planted on 27 October 2006 before the onset of the rainfall season. Reference evapotranspiration (ETo) was calculated from observed daily temperature, relative humidity, wind speed and solar irradiance data where automated weather stations (AWS) were available using a software package ETo Calculator (FAO, 2009) based on the procedures described by Allen et al. (1998). The weather at the different sites showed considerable variation which is useful in the validation of AquaCrop to ensure the results are widely applicable to the general climate of Zimbabwe. Previous model testing of AquaCrop were also done under varying climatic conditions (Heng et al., 2009; Hsiao et al., 2009).
By considering the soil water retention characteristics influencing the total available water from a soil baseline study of the sites (Mhizha, 2010), 2 major soil types emerged and were considered representative for the study sites as described in Table 8. Sandy clay loam soils were predominant at Th67, Th78, Ar01, Ar23, Ar56, Gr78 and Mt78, while deep uniform sandy soils were observed at Kt78 and Mr78 fields (Table 1).
Maximum effective rooting depth (Z) estimated at Thornpark was 0.8 m, a result which is consistent with the observed depth of the soil at Thornpark reported in the soil baseline study carried out at this site (Mhizha, 2010). Water retention characteristics for the 2 soil types indicate total available soil water content of 90 mm/m and 130 mm/m for the sandy and sandy clay loam soils respectively. These results compare well with reported values of 90 mm/m and 127 mm/m for similar soils in Zimbabwe (Raes et al., 2004).
For the Thornpark trials, statistical analysis of final above-ground biomass and yield data was done by means of analysis of variance (ANOVA) and separation of means carried out on the observed data using Statistical Analysis Software (SAS version 9.3.1). The least significant difference at 5% level (LSD005) was used to separate the means of the main and interaction effects where appropriate.
In Table 9, it is shown that yield for each sowing date was significantly different from the others in the 2006/07 trial, with an observed decrease in yield with delayed sowing. Since the 2006/07 season was a relatively dry season, it can be suggested, that based on these results, the effect of sowing date on maize yield is clearly apparent in dry years although further trials over more seasons need to be studied to confirm this.
There was no significant difference between means of all three varieties in the two rainfed trials of 2006/07 and 2007/08 (Table 10). Also, comparing the overall means with the potential yields of the three varieties in the region as provided by SeedCO (2005) - 4-8 Mg/ha for the early maturing, 5-10 Mg/ha for the medium maturing and 7-13 Mg/ha for the late maturing variety - it can be observed that the rainfed yields were significantly below the potential values. This yield gap was part of the reason for calibration of AquaCrop parameters which reduced simulated yields to levels comparable to observations under rainfed conditions.
Model calibration
The list of parameters adjusted during calibration is presented in Table 3. The combined effect of adjusting CCx and canopy decline from mid-season improved the simulation of CC. The biomass water productivity (WPb*) and reference harvest index (HIo) input parameters of AquaCrop were adjusted from the default values of 33.7 g/m2 and 48% to 29 g/m2 and 36%, respectively, to account for the low soil fertility conditions. The adjusted WPb* led to improved simulation of the final above-ground biomass.
The biomass water productivity parameter was adjusted according to Eq. (4):
Tr is simulated crop transpiration the conservative normalised WPb* = 33.7 g/m2
WPadj. is the normalised WPb* adjusted for the low soil fertility conditions
Bobs is the observed final above-ground biomass.
This approach assumes the model is simulating crop transpiration accurately such that Tr is approximately the actual crop transpiration. Reference harvest index HIo was adjusted by assuming correct simulation of final above-ground biomass and using the relationship between biomass and grain yield. Table 11 presents the statistical parameters for assessing the model performance after local calibration. The coefficients of determination for all variables tested in the calibration were above 0.75, showing a high linear correlation between simulated and observed parameters. The highest RMSE percentage of 16.1% was calculated for biomass accumulation. The relatively large error was attributed to higher random errors in measuring observed biomass. However, the Nash-Sutcliffe model efficiency coefficients were all above 0.75 indicating a good overall model performance.
Scatter plots of simulated against observed final above-ground biomass and grain yield are shown in Fig. 2. The correlation (R2 = 0.86 and 0.96 for grain yield and biomass, respectively) was good while slopes of 0.92 and 0.77 for yield and biomass, respectively, were also quite good for the relatively small datasets used, implying a good fit between calibrated model output and observations. The results of the assessment of model performance after calibration were satisfactory, showing AquaCrop to be capable of simulating maize yield responses to variety and sowing dates.
Model validation
Results of validation of AquaCrop with a different dataset (Table 2) are presented as scatter plots of the simulated against observed final above-ground biomass and grain yield in Fig. 3. With R2 = 0.86 and 0.96 for grain yield and biomass, respectively, as well slopes of 0.79 and 0.71 for grain yield and biomass, respectively, the fit between observed and modelled parameters during validation was good. AquaCrop was able to simulate above-ground final biomass and grain yield for 6 stations around the maize belt of Zimbabwe. The statistical measures of model performance during validation are presented in Table 12. The EF value for biomass (0.64) is lower than that for grain yield (0.81), possibly due to the relative difficulty in measuring observed biomass when compared to grain yield. Zinyengere et al. (2011) and Masanganise et al. (2012) used AquaCrop to simulate maize yields in Zimbabwe without calibrating it, but the order of magnitude and sensitivity of the simulations to variety and sowing dates were reported to be satistfactory. This study provides further evidence that AquaCrop can be used to reliably simulate maize yields for common varieties grown at different locations in Zimbabwe, although further testing of the model under farmers' field conditions can still be valuable.
Model application for developing sowing guidelines
The developed sowing guidelines were summarised into simple charts presented in Table 13 (deep soil) and Table 14 (shallow soil).
Tables 13 and 14 show the 10-day periods in which sowing is recommended in order to obtain maximum yield under rainfed cultivation of maize in the maize belt, at its border and outside regions and for the two soil depths considered. The expected average yield is indicated together with expected yield range, defined by the difference between yields with probabilities of exceedance of 80% and 20%. The range is an indicator of the yield variation due to inter-annual variability in quality of the rainfall season at the concerned location with wider ranges indicating higher risks of yield variability. The depth of grey shading indicates the strength of recommendation. Although the best option for the farmer in each of the three regions is to sow all fields in the recommended dekad, staggered sowing in Zimbabwe is often practiced due to labour constraints. In this case, the degree of shading indicates the order of preference for sowing periods. For late sowing, short maturing varieties should be used.
Storage capacity of the deep soil (Table 13) allows later sowing dates than on the shallow soil (Table 14). This results in higher yields on the deep soil because the uncertainty at the start of the rainy season can be avoided. To avoid insufficient rainfall at the end of the growing season, sowing should be as early as possible on the shallow soil. From the simulated expected mean yield results, it can be concluded that highest yields can be obtained inside the maize belt while maize production can still be considered viable in the border region. Farming maize outside the maize belt is not recommended because of the low average yields and high variation expected. This wide range in expected yields was also reported by Zinyengere et al. (2011), who reported expected maize yields for Masvingo (outside the maize belt) ranging from 0 to 6 t/ha after using an uncalibrated version of AquaCrop and a weather generator. Mhizha et al. (2012) used analysis of relative transpiration to show that the quality and length of the rainfall season is more suited for rainfall in the maize belt than outside it, concluding that deeper soils and shorter varieties are desirable to obtain better yields outside the maize belt. Phillips et al. (2002) reported that maize is the dominant crop in the wetter zones of Zimbabwe, while in the drier zones the more drought-tolerant crops, pearl millet (Pennisetum glaucum L.) and sorghum [Sorghum bicolor (L.) Moench], and livestock herding are the dominant components of the farming system.
The results presents the recommended sowing windows for 3 climate zones of Zimbabwe and 2 typical soils. The sowing windows span from the third 10-day period of November in all areas to the third 10-day period of December in the marginal zone outside the maize belt. The sowing periods were determined by optimising mean yields and therefore were influenced by extreme values. It is recommended that the guidelines be used in conjunction with seasonal climate forecasts to reduce effect of inter-annual variability in rainfall patterns. The main advantage of these sowing recommendations is that they are based not only on rainfall characteristics at the start of the season but also take into account the rest of the growing season's characteristics together with the crop and soil characteristics.
AquaCrop for maize was able to simulate grain yield accurately for the local environmental conditions of Zimbabwe after fine-tuning for soil fertility. The local calibration of AquaCrop considered the local varieties' characteristics and local fertility management levels, which were below optimum levels. Overall, model validation results were satisfactory and it was concluded that AquaCrop could simulate with satisfactory accuracy maize production under rainfed conditions in Zimbabwe.
The validated AquaCrop model was applied together with an optimisation model to select optimum sowing dates and varieties for climate stations in and around Zimbabwe's maize belt. Optimum sowing time was shown to be sensitive to soil depth. Deep soils had a wider sowing window while shallow soils required very early sowing to give better yields in comparison. However, the optimisation procedure used can be improved by including in its formulation other important parameters, such as labour, which influence overall production at farm level.
The developed sowing guidelines were summarised into a simple chart that is easy to use as a general guide applicable to the study area. However, the developed guidelines are still rather general and are in terms of sowing date occurrences not calendar days. Their application at farm level is therefore difficult unless they are simplified further. The major outstanding point is that of determining when the first, second, etc., sowing date occurrence has arrived at a particular farm site. Since sowing date occurrences vary from year to year, it would be useful if the short-term weather forecasts could incorporate sowing date occurrences to help farmers keep track of the progression of the sowing season and hence be able to implement the sowing guidelines.
It must be noted that the results of this study were developed by linking real historical climate data; typical soil characteristics for the locations; current maize cultivar characteristics as well as prevailing management practices like fertilisation rates and planting densities. Should any of these be considered to have changed, e.g., climate due to climate change, the model may need to be re-run to come up with updated and relevant guidelines. Modelling is not a substitute for field experiments but rather is complementary. It is therefore recommended to test the model results by field experiments in the study area in order to validate the practical applicability of the recommendations of this study.
This research was funded by the Flemish Inter-University Council of Belgium (VLIR - IUC) through PhD and Post-Doc fellowships. The authors are grateful to Olivier Crespo for a critical review of the revised manuscript.
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MHIZHA T, GEERTS S, VANUYTRECHT E, MAKARAU A and RAES D (2012) Relative transpiration as a decision tool in crop management: a case for rainfed maize in Zimbabwe. Afr. Crop Sci. J. 20 (1) 47-57. [ Links ]
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PHILLIPS JG, CANE MA and ROSENZWEIG C (1998) ENSO, seasonal rainfall patterns and simulated maize yield variability in Zimbabwe. Agric. For. Meteorol. 90 39-50. [ Links ]
PINSTRUP-ANDERSEN P, PANDYA-LORCH R and ROSEGRANT MW (1999) World food prospects: Critical issues for the early twenty-first century. URL: http://www.ucc.ie/famine/conference/papers/Pandya-Lorch.pdf (Accessed 29 August 2008). [ Links ]
RAES D, SITHOLE A, MAKARAU A and MILFORD, J (2004) Evaluation of first sowing dates recommended by criteria currently used in Zimbabwe. Agric. For. Meteorol. 125 177-185. [ Links ]
RAES D, STEDUTO P, HSIAO TC and FERERES E (2009a) AquaCrop-The FAO crop model for predicting yield response to water: II. Main algorithms and soft ware description. Agron. J. 101 438-447. [ Links ]
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ROCKSTRÖM J, BARRON J and FOX P (2003) Water productivity in rain-fed agriculture: challenges and opportunities for smallholder farmers in drought-prone tropical agroecosystems. In: Kijne JW, Barker R and Molden D (eds.) Water Productivity in Agriculture: Limits and Opportunities for Improvement. International Water Management Institute (IWMI), Colombo. [ Links ]
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STEDUTO P, HSIAO TC, RAES D, FERERES E (2009) AquaCrop-the FAO crop model to simulate yield response to water: I. Concepts and underlying principles. Agron. J. 101 426-437. [ Links ]
STRICEVIC R, COSICA M, N DJUROVICA N, PEJIC B AND MAKSIMOVICC L (2011) Assessment of the FAO AquaCrop model in the simulation of rainfed and supplementally irrigated maize, sugar beet and sunflower. Agric. Water Manage. 98 (10) 1615-1621. [ Links ]
TODOROVIC M, ALBRIZIO R, ZIVOTIC L, ABI SAAB M, STWCKLE C and STEDUTO P (2009) Assessment of AquaCrop, CropSyst and WOFOST models in the simulation of sunflower growth under different water regimes. Agron. J. 101 509-521. [ Links ]
VINCENT V and THOMAS RG (1961) An agricultural survey of Southern Rhodesia: Part I: agro-ecological survey. Government Printer, Salisbury. [ Links ]
WGLARCZYK S (1998) The interdependence and applicability of some statistical quality measures for hydrological models. J. Hydrol. 206 98-103. [ Links ]
YANG HS, DOBERMANN A, LINDQUIST JL, WALTERS DT, ARKE-BAUER TJ and CASSMAN KG (2004) Hybrid-maize-a maize simulation model that combines two crop modeling approaches. Field Crops Res. 87 131-154. [ Links ]
ZINYENGERE N, MHIZHA T, MASHONJOWA E, CHIPINDU B, GEERTS S and RAES D (2011) Using seasonal climate forecasts to improve maize production decision support in Zimbabwe. Agric. For. Meteorol. 151 (12) 1792-1799. [ Links ]
Teddious Mhizha
+263 712 798260; fax: +263 4 307130
e-mail: firstname.lastname@example.com
Received 29 January 2013
Accepted in revised form 3 March 2014


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¶Floating point specials and shader emulation
I decided to work a bit more on my shader compiler and emulator last night, and ran into some unexpectedly ugly problems with floating point specials.
The first problem had to do with the following innocent looking expression:
This returns the magnitude of a vector. The conventional way to compute this is to compute the squared magnitude by taking the dot product of the vector with itself -- the vector analog of squaring a scalar -- and then taking the square root of the result. It turns out that shader hardware doesn't actually support a direct square root. The reciprocal square root, 1/sqrt(x) is easier to compute, and it's also useful in some other cases, most notably normalizing a vector. In this particular case, though, we need the normal square root, and therefore we need to invert it in the assembly:
dp3 r0.x, r_vec, r_vec ;compute dot(vec, vec)
rsq r0.x, r0.x ;compute reciprocal square root of squared magnitude
rcp r0.x, r0.x ;invert reciprocal square root
This little code fragment has a major surprise lurking in it, which may not be apparent until you try optimizing it. Both rsq and rcp are scalar instructions, so in cases where multiple magnitudes are being computed, the temptation is high to replace 1/rsqrt(x) with x*rsqrt(x) instead to take advantage of the much more available mul instruction:
dp3 r0.x, r_vec, r_vec
rsq r0.y, r0.x
mul r0.x, r0.x, r0.y
This works just fine... until you have the misfortune of trying to compute the length of a zero vector. In that case, the reciprocal square root operation returns +Infinity, and then the next thing that happens is the computation 0*+Infinity, which then returns a NaN (invalid result). Suck. Therefore, for the general case, that rcp has to stay there.
The real gotcha comes when you try implementing the rsq and rcp instructions in software. Reciprocal is a very slow instruction on most FPUs, being done with the divide unit and usually taking dozens of nonpipelineable clocks. Reciprocal square root may not even exist in full precision form, and 1/sqrt(x) is a horribly painful way to implement it. If you want to implement this fragment quickly in SSE, you need to take advantage of the rcpps and rsqrtps instructions, which are very fast and work in parallel on four values. They only provide limited precision up to about 2^-12, though. The WPF shader engine just goes ahead and uses the approximation result directly, which works and is accurate enough for half precision (10 bit mantissa), but technically it's not Direct3D compliant as 22 bits of precision are needed.
The usual way to improve the accuracy of the reciprocal and reciprocal square root operations is by iteration through Newton's Method. For the reciprocal, it looks like this:
x = reciprocal_approx(c);
x' = x * (2 - x * c);
...and for the reciprocal square root, it looks like this:
x = rsqrt_approx(c);
x' = 0.5 * x * (3 - x*x*c);
Assuming that you have a good estimate, these will tend to double the number of significant digits per iteration, which means that just one iteration will give us pretty good precision, and quickly, too. And unfortunately wrong, as I discovered when I implemented it. The problem is once again zero. In order for the zero case to work, we need rsq to transform 0 -> Inf and rcp to transform Inf -> 0, but thanks to the x*c expression in both of these iterations, you once again get 0 * Inf = NaN. The way I fixed it was to insert a couple of carefully placed min/max operations in the iteration, although I'm not quite sure they're 100% correct.
The specials struck again when I was trying to optimize the code generated for a gamma correction shader. Gamma correction is primarily a power operation, which expands as follows:
pow(x, y) = exp(y * log(x))
If you actually try gamma correcting an image in this manner, you'll be waiting a long time for the result. For limited precision (8-bit), you can get away with a lookup table, but that doesn't scale well to higher precision or vector computations and definitely not to a shader where floating point is involved. Therefore, in order to get a faster version working, I had to implement the log and exp instructions, which compute the base 2 logarithm and exponential functions. SSE doesn't provide you any help to do this, so you're stuck implementing this from the ground floor. It's a bit like an old BASIC interpreter, except at least you start with add and multiply. This triggered the following conversation with a friend:
"What are you doing?"
"I'm implementing the log() and exp() functions."
"Doesn't the runtime provide those?"
"This is the runtime."
Anyway, I ended up implementing exp2(x) = c*floor(x) + f(x - floor(x)) and log2(x) = c*exponent(x) + g(mantissa(x)). For the most part they're not too hard, as long as you find good polynomial expansions and make sure it's exact at the right values, i.e. you don't want exp(0) = 1.004. In the end, I used a fifth-order polynomial for exp2() and a first-order Padé approximation with a change of variables for log2()... but I digress.
As you have probably already guessed, zero rears its ugly head again here, because 0^y becomes exp2(y * log2(0)), and for this to work you need log2(0) = -Infinity and exp2(-Infinity) = 0. A couple of well-placed min/max operations in the expansions once again fixed the SSE version, but I unexpectedly ran into problems with the x87 version. I hadn't bothered to optimize the x87 version, so it simply called into expf() and scaled the result. Since I compile with /fp:fast /Oi, expf() ended up getting expanded in intrinsic form like this:
fld st(0)
fxch st(1)
fsub st, st(1)
If you look closely, you'll see that this computes (x - round(x)), which in this case is -Inf - (-Inf) = NaN. There are two basic ways to fix this. One is to force the runtime library version of the function, which is faster for SSE2 but unfortunately quite slow for x87. The other way, which is what I did, is to just check for infinity and special-case the result.
Ordinarily I don't think much about floating point specials, and the last place I would have expected to find them is in a pixel shader. I have to say it's been a bit of a humbling (and frustrating) experience.


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Event photos taken by Eileen Miller.
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Related Info
James Beard Foundation events permit guests age 21 and older.


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01 Aug 2013
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text:
Our children Must die!Mohit after Rohit commits suicide in yet another central university!
Muslim,Dalits and Adivasi reamin bonded Vote Bank subjected to continuous persecution in Free India!
Here you are at last!#justice forrohitHOKKOLOROB breaks the spine of Manusmriti!Continue Jai Bhim Comrade!
Now I plan the ambush.Whoever cares for me in the field where I worked for four decades without any break,my foes and friends as well,just visit the nearby campus immedeitely,ambush it with persecution hearing and report so that the rot would be uprooted.RUSH.
Nothing to be diverted!
Divided we stand!
Our children Must die!
Palash Biswas
Here you areat last!
#justice forrohitHOKKOLOROB breaks the spine of Manusmriti!Continue Jai Bhim Comrade!
Of course,it is an obligation to manage the floor consensus most wanted to make leagal everything illegal,immoral and unethical that HRD ministry to meet VCs on ending campus discrimination
The Union HRD Ministry has convened a meeting of 46 vice-chancellors of all the universities on February 18 in what is being viewed as an attempt by the government to preempt Opposition attack on the issue in Parliament.
Nothing to be diverted!
Our children Must die!
Mohit after Rohit commits suicide in yet another central university!
Though,No suicide note has been recovered from his room but and documents recovered from the room are being examined, additional SP Ajmer Rural Vinit Kumar Bansal said.
Mind you it is official version of the age old holocaust still contiuing!
Just note!A PhD scholar allegedly committed suicide by hanging himself in his hostel room in Central University of Rajasthan (CURAJ) in Ajmer.
And read between the lines,the not to be published truth of apartheid so brute to reduce us Nimityamatra vedic status in the Hindi nation ruled by the governance of fascism!
PhD scholar allegedly committed suicide by hanging himself in his hostel room in Central University of Rajasthan (CURAJ) in Ajmer.
"Mohit Chauhan committed suicide in his hostel room on Friday evening. The body was shifted to a local hospital and his parents living in Uttar Pradesh have been informed about the matter," police said.
No suicide note has been recovered from his room but and documents recovered from the room are being examined, additional SP Ajmer Rural Vinit Kumar Bansal said.
"Initial information suggested that he was under depression. There were also allegations that his guide was harassing him," he said.
Investigation is on to ascertain the cause of the suicide.
Mind you ,the nation failed to pay the deserved tribute to those three girls who committed suicide in Chennai medical college.
This morning my friend and eminent journalist Jaideb Hardikar called me and we discussed a little because we could not continue as network failed.We would be talking sooner or later.
I suggested him to ambush the university campus for the most wanted campus persecution replicating campus recruitment.
I would be talking to all my friends in media.Whoever wants to talk to me I am available round the clock and I die to see the holocaust!
As I warned earlier to all the criminals behaving apartheid in the Indian higher education campus that they must spare our children irrespective of identities otherwise I,personally would not leave any stone unturned and they should be all set to face the consequence.
Now I plan the ambush.Whoever cares for me in the field where I worked for four decades without any break,my foes and friends as well,jus visit the nearby campus immediately,ambush it with persecution hearing and report so that the rot would be uprooted.
Identity is enough for them.
It is the master key to hold the nation bonded,slave!
Please sash it with all the strike power of hell and heaven!
They would live and die with their respective identities and would never never dare to encroach their limit within the identities.Caste System is the ultimate truth in social realism for every Indian citizen in the Hindu nation irrespective of language,caste,religion or race.
If this has to be changed,please break all those barriers as soon as possible lest your children must die.
They would kill you with your identity which is the greatest atomic weapon of mass destruction.
#justiceforrohit/HOKKOLROB continues and the persecution also continues!
The ruling hegemony has got the ultimate weapon of mass destruction as we stand divided and partitioned within inflicted with false,blind nationalism!
Our children must die!
Thus,Indian Express reports:
Caste came up in 3 suicide probes at Hyderabad University
The HRD Ministry wants a judicial commission to probe the events that led to the suicide on January 17 of Vemula.
The University of Hyderabad had all the warning it needed before Dalit research scholar Rohith Vemula committed suicide last month. Three red flags, in the form of three suicides by Dalit students within six years. And three probes that arrived at the same conclusion: this was no campus for the marginalised.
The HRD Ministry wants a judicial commission to probe the events that led to the suicide on January 17 of Vemula, who was among five Dalits suspended by the university for allegedly assaulting an ABVP leader. But the findings of the three committees that probed the three suicides on campus between 2008 and 2014 were clear: the Dalit students faced a "sense of alienation" and "institutional discrimination" owing to "caste consideration".
One of those committees, headed by retired Supreme Court judge Justice K Ramaswamy, stated in its report: "Because of the insensitivity towards problems faced by the students belonging to the aforesaid social groups, frequent occurrences of suicides are taking place."
Senthil Kumar committed sucide in 2008 while P Raju and Madari Venkatesh killed themslves in 2013. The three suicides, like that of Rohith Vemula, happened inside the New Research Scholars (NRS) Hostel on campus.
'Was tense about supervisor' 2008: Prof V Pavarala committee report on Senthil Kumar's suicide On February 28, 2008, Kumar, a PhD student in Physics, consumed poison. The report noted, "Senthil Kumar came from a poor Dalit family from Tamil Nadu, probably a first-generation university student.
According to his friends, he was also struggling to send some money home. Many of his friends remember him as a strong and brave person, often jovial in his mannerisms. He was interested in reading Tamil literature and would engage in discussions with friends in the Humanities on such topics as modernity and deconstruction.
" Senthil's friends told the committee that he wished to explore options abroad or move to another university. "
He was also apparently under some tension about the supervisor with whom he would have to eventually work for his PhD.
Students reported that in the last week or so, leading up to his death, Senthil was considerably uneasy and found it difficult to sleep," stated the report.
The report concluded that most students affected by "ambiguous procedures" in the university were SCs and STs.
Among its 12 recommendations were:
* Every school/department must have a grievance redressal mechanism which the students can turn to without fear of reprisals.
* There is a need for all faculty members to internalise greater sensitivity about students belonging to the reserved categories.
* It is important to be pro-active in mentoring and advising students who come from less privileged backgrounds, both in the classroom and outside.
* It is imperative that a top-ranking central institution takes a lead in nurturing and promoting a corps of scientists from among the marginalised sections.
'No grievance redressal system' 2013:
V Krishna committee report on P Raju's suicide. On March 19, 2013, P Raju, a student of the Integrated Master of Arts (IMA) and an officebearer in the Dalit Students Federation (DSF), hanged himself.
After performing well in the first three years, Raju failed in four papers. And according to rules, he would not have been allowed to appear for his eighth semester examinations unless he cleared at least two papers. Raju wrote the exams in January 2013 and was awaiting his results when he committed suicide.
When the results were declared, he had cleared only one paper.
Raju's friends told the committee that he had also developed "a crush" on a classmate who had helped him develop his English language skills but was "demoralised" when he realised that the feelings were not mutual.
"Some students… spoke of a sense of alienation — distinctly accentuated in the case of Dalit students — in coping with the demands of the regular MA programme.
This was also corroborated by some teachers, although the explanation offered for variation in performance was that in the MA segment, the academic competition was more intense," stated the report.
"While Raju's personal setbacks may have left him distressed, his academic burdens seem to have only compounded the problem… neither his peer community at large nor his teachers showed the receptivity that could have addressed the seriousness of (his) plight," it said.
The committee also observed that no grievance redressal mechanism was evident.
"The Committee did not find any evidence of a grievance redressal mechanism in place in The Centre for Applied Linguistics and Translation Studies (CALTS)… Informal consultation with departments/ schools/ centres also revealed the absence of such a mechanism," the report stated. 'Antipathy clearly apparent' 2014:
Justice K Ramaswamy committee report on Madari Venkatesh's suicide. On November 24, 2013, Madari Venkatesh, a postgraduate researcher in chemistry consumed poison.
A committee, under Justice K Ramaswamy, found that Venkatesh was not allotted a supervisor since he joined the School of Chemistry despite several efforts, including a letter to then Vice-Chancellor Prof Ramakrishna Ramaswamy.
"No Doctoral Committee was constituted to supervise his research which is mandatory. Though six faculty members from School of Chemistry were available, none was willing to supervise his research.
Whatever research he had done, it was only by his self effort… He was discriminated on the ground of caste consideration," noted the committee.
Its report stated, "It is the consequence of institutional discrimination and systematic exercise of exclusive and oppressive behaviour of the Institution and the faculty of the School of Chemistry."
It further observed, "The antagonism, antipathy and insensitive mindset of the faculty, in particular of the School of Chemistry… towards the student belonging to marginalized social groups is clearly apparent."
Justice Ramaswamy also noted that the suggestions made by the V Pavarala and V Krishna committees were not implemented in full.
- See more at: http://indianexpress.com/article/india/india-news-india/caste-came-up-in-3-suicide-probes-at-hyderabad-university/#sthash.Cv7pV6rm.dpuf


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Yorkshire Pudding Blank Mini Notecards
by Charlotte Gale
These blank Yorkshire notecards feature a character from my popular 'Too Many Sprouts' range. They are perfect as Christmas thank you cards.
Cards are available individually or in packs of 4 (single design) and come with envelopes.
The size of these cards when folded is 110mm x 110mm. All my cards are standard UK postage.
Photographic Greetings Cards
Designed by Yorkshire photographer Charlotte Gale
Standard UK Postage
All our cards are standard UK postage size and are supplied with envelopes
Printed in the UK
All our cards are professionally printed in the UK on high quality board


text: Dizengoff Nigeria is a well known and trusted brand throughout many of Africa's farming communities. With years of expertise in the field of Drip Irrigation and representing global leaders in the field of irrigation, Dizengoff Nigeria offers tailor-made solution to a wide array of irrigation needs. Reliable water supplies are essential for agriculture. Dizengoff Nigeria enables farmers to irrigate their land more effectively, using technologies that give precise water coverage, even with low volumes of water. We offer water treatment, filtration, pumping equipment and high quality durable pipes to help secure your water supply. Dizengoff Nigeria team can guide and implement all irrigation and water supply projects, whether it is for irrigation, potable water for towns and communities, municipal services, or pumping and control systems, as well as removal and treatment of waste water. Dizengoff Nigeria is a well known and trusted brand throughout many of Africa's farming communities, respected for its vast range of innovative irrigation methods that fit the growing needs of water saving and modern products for agriculture and gardening. We install and maintain drip lines, sprinklers, micro-sprinklers, micro-jets, rain guns and center pivot, and offer irrigation solutions used for various crops such as fruits, vegetables, flowers and trees, combining the advantage of low water volume and precision coverage.


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User talk:126.96.36.199
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Business Card Reader for Pipedrive CRMFree
Business Card Reader for Pipedrive CRM is the easiest and quickest way to save your business cards info into Pipedrive CRM. Snap a photo of business card and Business Card Reader for Pipedrive CRM instantly exports all card data directly into your CRM system. Moreover, this innovative solution allows you to find out more information about your potential client, partner, or colleague. Just two taps and you get a bird's-eye view of the following information*: - personal info: Company name, Job title, Department, Address, Social network profiles, messengers etc. HOW IT WORKS With our app you can save a business card in just 2 clicks and 10 seconds of your time! https://www.youtube.com/watch?v=HS3zBjgEkNQ FAQ page: http://magneticonemobile.com/products/business-card-reader-pipedrive-crm.html#themo_faq_1 We are here to help! Feel free to send us any questions or suggestions you have! E-mail for contact: email@example.com
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When I see a lipstick with moisturizing qualities, the first thing that comes to mind is "Ah, this must not be very pigmented". That's the typical trade-off, isn't it? You get hydration at the cost of pigmentation and lipsticks that are more pigmented are usually very drying.
Armed with years of history in producing high quality luxury makeup, Estée Lauder unveils the NEW Pure Color Envy Shine Sculpting Lipsticks, which keep my lips moisturized without compromising color.
I tried on these Estée Lauder Pure Color Envy Shine Sculpting Lipsticks with a very open mind (you know, bad experience with many others) and was BLOWN AWAY when they not only glided on my lips effortlessly, their pigmentation and longevity were impressive! WOWWW!!
Brilliant Shades Made For Asian Women
Exclusively developed to complement the natural beauty of Asian women, these 16 beautifully feminine shades are broken down into 4 categories – Nudes to Browns, Pinks to Berries, Corals to Red, Mauves to Plums, so you'll definitely find a shade that suits you perfectly.
Left to right: Surreal Sun, Pink Dragon, Charmed, Innocent
Left to right: Surreal Sun, Pink Dragon, Charmed, Innocent
What am I talking about?!?! I doubt anyone can walk away with only one shade after getting to try first-hand just how amazingly comfortable and creamy these are on the lips without compromising color!
Read on for a MEGA GIVEAWAY!! You're gonna go craaaazyyy!!! 😛
Surreal Sun
Beautiful and bright peachy-pink-coral. My favorite shade of the lot because it's all bright and cheery and feminine at the same time. Love how it instantly brightens up my face! When I met up with a friend whom I haven't met in a long while, the first thing she said was "OMG I LOVE YOUR LIP COLOR!!". No 'hello'. Lol.
Estée Lauder Pure Color Envy Shine Sculpting Lipstick Illuminate - Surreal Sun
Pink Dragon
Mauve, leaning pink. I like Pink Dragon a lot too. It's a very wearable shade of pink, not too loud, but enough to make people notice the soft rosy effect it brings to your face.
Estée Lauder Pure Color Envy Shine Sculpting Lipstick Illuminate - Pink Dragon
Warm salmon, almost reddish-brown on me. This would make a very good lip color for a corporate environment. It doesn't look too strong for a professional look, but enough to show that you have something on your lips to look put-together. This is that kind of shade that slowly grows on you. =)
Estée Lauder Pure Color Envy Shine Sculpting Lipstick Illuminate - Charmed
Nude beige with a slight hint of coral. I'm not a fan of nudes and browns due to the strong yellow undertones in my skin which causes any nude and brown lipsticks to make me look pale and sickly. The 'nudeness' of Innocent is still bearable due to the warm orange undertones, but it's not the kind of color I would reach out for. I love BRIGHT! BRIGHT! BRIGHT! =D But I know many people look great with nude lipsticks, especially when they want to play up the eyes more.
Estée Lauder Pure Color Envy Shine Sculpting Lipstick Illuminate - Innocent
Their incredible color payoff is attributed to an Advanced True Vision Technology that uses innovative sculpted pigments to provide color that SCULPT your pout to make it look fuller and more dimensional.
Swatches for you!
Left to right: Surreal Sun, Pink Dragon, Charmed, Innocent
Pure Hydration That Lasts
Most moisturizing lipsticks tend to have poor lasting power, but Estée Lauder's new range of lipsticks are loaded with Hyaluronic Acid that attracts, capture and seal in moisture for long-lasting hydration.
I have a bad habit of pursing and licking my lips very often, but these lipsticks last me a good 4-5 hours, the brighter colors – Surreal Sun and Pink Dragon last longer on my lips.
I'm truly in love with the formula. Lightweight yet pigmented, not sticky or gooey, there was no feathering and I didn't have to use a lipliner or lip brush to apply the lipstick – just straight from the bullet!
Estée Lauder Pure Color Envy Shine Sculpting Lipstick Illuminate - Surreal Sun
It's like a magical formula that hugs my lips but doesn't settle into the lines of my dry lips. If you want lips that look juicy and plump, you gotta get some of these Pure Color Envy Shine Lipsticks! =D
Estée Lauder Pure Color Envy Shine Sculpting Lipstick Illuminate - Pink Dragon
You Deserve To Shine
The Estée Lauder Pure Color Envy Shine Sculpting Lipsticks truly work to illuminate and sculpt your lips and the result is a shine that speaks of sophistication and luxury.
Ultrachic Design
The chic, shiny, navy packaging is also Estée Lauder's first redesign in more than 20 years. These hydrating and sculpting lipsticks are housed in an innovative, magnetic closure that clicks the cap shut.
Also, I bet you'll open and close then open it again just to make it click back. When I'm using the mouse with my right hand, my left hand plays with the magnetic closure - open-close-open-close-open-close. Very therapeutic. HAHAHA.
Oozing sleekness and class in a slim, navy case, it's like carrying a piece of luxury in your purse.
You can find the Estée Lauder Pure Color Envy Shine Sculpting Lipstick Illuminate at all Estée Lauder counters in Singapore. Find out more info at the Estée Lauder official website!
And now,
I have a question for you:
Would you be very happy if you could own some wonderful Estée Lauder products?
I knew you would! 😀
Estée Lauder is giving TEN LUCKY WINNERS $100 worth of Estée Lauder products EACH. OMG I WANT TO JOIN TOO!!!!
How to Win:
- Take a photo of yourself wearing your favorite Estée Lauder Envy Shine Color
- Upload it to Instagram, hashtag #LipstickEnvyShineSG (I'd like to keep updated too, so please follow and tag me in your post @bunbunmakeuptips)
- Winners will be announced on 10 May 2014 on Estée Lauder Facebook Page
- Contest ends 30 April 2014


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Wednesday, 29 June 2011
A House Full of Moxie
Thanks so much to Lisa at A House Full of Moxie for featuring me on her lovely blog today :o)
She also has a lovely & fresh-looking Etsy shop stocking a gorgeous selection of eco-friendly paper pencils and cute rubber stamps, so be sure to check it out!
Sunday, 5 June 2011
How to: Taped Screenprints
Learn how to create bold, geometric prints on fabric which can then be turned into cushion covers, tote bags, or stapled to wooden frames to be displayed as artwork. This simple technique uses everyday sellotape to mask off areas and (despite the title!) doesn't involve a screen at all.
Saturday, 4 June 2011
How to: Make an Upcycled T-Shirt Bag
Learn how to recycled boring old t shirts that you never wear anymore into a funky new bag you won't be able to put down!
Posted by Leanne Garrity at 01:14 225 comments:
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Product Details
Andersen 20510 Double-Hung Full Screen
- Works with 400 Series Tilt Wash windows manufactured from 1992 to Present.
- Available in Standard or TruScene screens.
- The replacement screen has a center support bar.
- This screen measures 23-7/8" wide by 70-27/32" high.
What are TruScene® Screens
- TruScene screens are 50% clearer than standard screens, allowing you to really appreciate your view.
- TruScene screens are made with a nearly invisible micro fine stainless steel screen mesh that keeps out even the smallest insects.
- TruScene screens provide superior ventilation and let more sunlight into your home.


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Did you guys know what you wanted to be when you grew up?
I didn't for a long time. I went through phases: President of the United States (when I was 6), missionary (when I was 10– not even kidding), teacher (when I was 14), nurse (when I was 18), and then in college I just sort of gave up trying to find that thing, because none of those things were really what I wanted.
Do you sense a theme, though?
Yep, I'm definitely a Caregiver. My ArchetypeMe profile quiz says I'm 31% Caregiver, 28% Intellectual, and 21% Creative. (In case you missed my last ArchetypeMe post, ArchetypeMe is a new website that is redefining "personal" search by helping you curate, express, and discover differently, through the filter of archetypes.) So I was on the right track with the missionary/teacher/nurse thing (and maybe even President of the United States, because when I was 6 I just thought you got to, like, give cookies to the whole country if you were President), but I hadn't hit on the thing that made me feel fulfilled in all the different areas of my personality.
I got my English lit degree, mostly because that was the subject I loved most and I was under pressure to pick a major. And then I went into administrative work, where I stayed for many years, sort of branching out from time to time into customer support, or marketing, or accounting. It was fun, but not really fulfilling.
And during all that time when I'd been picking a major and sort of blindly stumbling through my administrative career, I'd been blogging. I was in love with blogging. I'd always loved writing, and I was pursuing a writing career on the side, too, but blogging gave me the instant gratification that I didn't get from writing novels or essays or short stories. Those things fulfilled the intellectual and creative parts of me, and my caregiver side got to jump in with volunteer work in my different writing and creative organizations.
Then, suddenly, at 31 (this past summer), I found myself for the first time in my adult life without gainful employment. All that was left was my blog and my not-quite-off-the-ground writing career.
In a miracle of perfect timing, good luck, and (hey, let's be honest) some skill on my part, the blog took off at just the right time and I found myself, finally, in a place where I felt really happy, challenged, and fulfilled in my career.
I'm still working on getting some more Caregiver in here (and stay tuned for an announcement on that in coming weeks), but for the first time in my life, what I'm doing every day gives me all of the good feels. And I am all about the good feels.
Don't forget to take the quiz yourself at www.ArchetypeMe.com!
To enter for a chance to win a $50 Visa gift card, answer this question in a comment below: Which archetypes are you? (You can find a list of the archetypes on the ArchetypeMe homepage at ArchetypeMe.com.)
No duplicate comments.
You may receive (2) total entries by selecting from the following entry methods:
- Leave a comment in response to the sweepstakes prompt on this post
- Tweet (public message) about this promotion; including exactly the following unique term in your tweet message: "#SweepstakesEntry #whatsyours"; and leave the URL to that tweet in a comment on this post
- Blog about this promotion, including a disclosure that you are receiving a sweepstakes entry in exchange for writing the blog post, and leave the URL to that post in a comment on this post
- For those with no Twitter or blog, read the official rules to learn about an alternate form of entry.
This giveaway is open to US Residents age 18 or older. Winners will be selected via random draw, and will be notified by e-mail. You have 72 hours to get back to me, otherwise a new winner will be selected.
The Official Rules are available here.
This sweepstakes runs from 2/13/13-3/15/13.
Be sure to visit the ArchetypeMe brand page on BlogHer.com where you can read other bloggers' posts and find more chances to win!


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Summer is the time when most of us rejoice, reach for the sunscreen and head outdoors. But an ever-growing number of people reach for tissue instead as pollen leaves eyes watering, noses running and spirits dwindling.
Hay fever is just one of a host of hypersensitivity allergic diseases that cause suffering worldwide and others, such as severe reactions to bee stings or eating peanuts, can be more serious and even fatal.
Now, scientists at the Salk Institute for Biological Studies have uncovered the molecular mechanisms behind such allergies, insight they hope will lead to new therapies, both to stop the summer sneezing and treat more severe allergic responses.
When our bodies encounter an allergen (such as pollen), specialized cells called mast cells undergo "de-granulation", during which they release the chemical histamine. Histamine in turn causes fluid to build up in the surrounding tissue. When this process is working normally it offers protection against the allergen but in people with allergic diseases, de-granulation can occur throughout the body, leading to severe inflammation and in the worst cases, anaphylactic shock and death.
And allergies are a growing problem the world over. "One out of three Japanese people suffer from allergies," says postdoctoral researcher Kotaro Suzuki, Ph.D., who led the current study.
During de-granulation, histamine is bundled into membrane bound sacks called vesicles, which then transport it to the cell surface. When the vesicles reach the surface they fuse with the outer membrane of the cell, spilling their contents into the extra-cellular space in a process known as exocytosis. To prevent this process from going overboard the scientists first had to understand how de-granulation is regulated.
Their hunch was that the allergic response would involve NF-êB, a protein found in the nucleus that regulates gene expression and was already known to be involved in other types of immune response. To investigate this hypothesis they focused on the role of IKK2, a protein kinase, which is essential for NF-êB activation.
To generate mast cells that were free of IKK2, the researchers transplanted mice that had no mast cells of their own with either normal mast cells or mast cells that lacked IKK2. Strikingly, mice with mast cells lacking IKK2 had reduced allergic reactions. The researchers assumed that the lowered response was due to reduced NF-êB, but to their surprise, inactivating NF-êB signaling alone did not have the same effect. "That was one of the first clues that IKK2 had other roles to play," says Verma.
"IKK2 knock out mast cells couldn't release enough histamine," added Suzuki 'but we still didn't know the molecular mechanisms." What they did know already was that de-granulation requires a collection of proteins known as the SNARE complex to assemble at the cell surface.
Suzuki and Verma used biochemical analysis to show that when an allergen is present, IKK2 binds to and activates one particular SNARE component called SNAP-23. Without IKK2, SNAP-23 is missing from the SNARE complex and conversely, when SNAP-23 is permanently activated, removing IKK2 no longer impairs de-granulation. "This is the first major feather on the cap of IKK2 in addition to NF-êB," says Verma.
But IKK2's role in the allergic response does not stop there - it multi-tasks. After the rapid "early phase" de-granulation response, mast cells undergo a "late-phase" reaction during which certain genes are turned on to help fight the allergen. Suzuki and Verma showed that the late-phase response also requires IKK2, but that this time it functions by its more usual route - via NF-êB.
The Salk researchers are now testing inhibitors of IKK2 as acute treatment for allergic reactions. Unlike anti-histamines, which are currently used to combat allergies, IKK2 inhibitors would have the added benefit of reducing both the early and late phase allergic responses.
And the newly discovered role for IKK2's may not be limited to allergic reactions. Many fundamental processes in our bodies involve exocytosis, ranging from secretion of insulin in the pancreas to synaptic transmission, the process by which signals are passed from one nerve cell to another. If IKK2 is involved in these processes it may have a role in other pathologies such as diabetes and nervous system diseases.
Source: Newswise


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Vice President
First Lady
Mrs. Cheney
News & Policies
History & Tours | Kids | Your Government | Appointments | Jobs | Contact | Graphic version
Email Updates | Español | Accessibility | Search | Privacy Policy | Help
Office of National Drug Control Policy, Director John P. Walters
John P. Walters is the Director of National Drug Control Policy (ONDCP)sworn in on December 7, 2001. As the Nations Drug Czar, Director Walters coordinates all aspects of Federal drug control programs and spending.
Under Director Walters leadership, youth drug use has dropped to its lowest levels since the early 1990s. The latest Monitoring the Future Study, released in December, 2006, indicated that 840,000 fewer young people are using drugs today than in 2001a 23 percent reduction. Teen marijuana use has dropped 25 percent, and teen methamphetamine, ecstasy, and LSD use have declined 50 percent or more over the past five years.
Emphasizing the need for a balanced approach to reducing drug use, Director Walters has overseen the creation and implementation of several key prevention and treatment programs:
The National Youth Anti-Drug Media Campaign has been restructured to improve its effectiveness.
More than 1,000 schools across the country now use the preventive power of random student drug testing to help young people resist peer pressure to use drugs and alcohol.
The number of community anti-drug coalitions supported by ONDCP has grown to over 700.
The Access to Recovery treatment initiative is providing vouchers for thousands of Americans struggling with addiction.
The Screening, Brief Intervention, and Referral and Treatment program is engaging the Nations health care system to diagnose and treat drug abuse, with the Medicaid system now offering reimbursement for such services.
Director Walters has also worked with our international partners to make significant progress in reducing the supply of illegal drugs:
The number of domestic methamphetamine labs have dropped 30 percent between 2005 and 2006, and continue downward.
Colombian cultivation of coca and production of cocaine have declined steeply, as has cultivation of opium poppy and production of heroin.
Working with U.S. authorities, Mexico has demonstrated unprecedented resolve to dismantle violent drug cartels.
Working with the United Nations Commission on Narcotic Drugs, Director Walters has focused on securing international cooperation in the control of pseudoephedrine and other precursor chemicals used to produce synthetic drugs.
Prior to returning to ONDCP, Mr. Walters served as president of the Philanthropy Roundtable. Previously he served at ONDCP as Chief of Staff and as Deputy Director for Supply Reduction and worked in the U.S. Department of Education and the National Endowment for the Humanities.
Your Government