Instruct: Given a question, retrieve documents that can help answer the question.
Query: How long can a human go without water?
In general, humans can survive for two to eight weeks without food, depending on stored body fat. Survival without water is usually limited to three or four days. About 36 million humans die every year from causes directly or indirectly related to starvation. Childhood malnutrition is also common and contributes to the global burden of disease. However global food distribution is not even, and obesity among some human populations has increased rapidly, leading to health complications and increased mortality in some developed, and a few developing countries. Worldwide over one billion people are obese, while in the United States 35% of people are obese, leading to this being described as an "obesity epidemic." Obesity is caused by consuming more calories than are expended, so excessive weight gain is usually caused by an energy-dense diet.
Carbohydrates are a common source of energy in living organisms; however, no single carbohydrate is an essential nutrient in humans. Humans are able to obtain all of their energy requirement from protein and fats, though the potential for some negative health effects of extreme carbohydrate restriction remains, as the issue has not been studied extensively yet. However, in the case of dietary fiber – indigestible carbohydrates which are not a source of energy – inadequate intake can lead to significant increases in mortality.
In May 2007, the Caudwell Xtreme Everest undertook a medical study of oxygen levels in human blood at extreme altitude. Over 200 volunteers climbed to Everest Base Camp where various medical tests were performed to examine blood oxygen levels. A small team also performed tests on the way to the summit. Even at base camp, the low partial pressure of oxygen had direct effect on blood oxygen saturation levels. At sea level, blood oxygen saturation is generally 98–99%. At base camp, blood saturation fell to between 85 and 87%. Blood samples taken at the summit indicated very low oxygen levels in the blood. A side effect of low blood oxygen is a greatly increased breathing rate, often 80–90 breaths per minute as opposed to a more typical 20–30. Exhaustion can occur merely attempting to breathe.
The African bush elephant is the largest and heaviest land animal on Earth, being up to tall at the shoulder and in weight (a male shot in 1974, near Mucusso, southern Angola). On average, males are about tall at the shoulder and in weight, while females are much smaller at about tall at the shoulder and in weight. Elephants attain their maximum stature when they complete the fusion of long-bone epiphyses, occurring in males around the age of 40 and females around the age of 25. Their large size means that they must consume around 50 gallons of water every day in order to stay hydrated.
"S. corneum" are sensitive to high pollution levels, particularly organic pollutants which foul the water, preventing the clams from effective feeding. As such, they are a bioindicator species whose presence may demonstrate that the water is relatively unpolluted. They are tolerant of anoxic locations however and can survive up to 400 days at and 9 days at without oxygen. This allows them to burrow down into sand, mud, gravel and other inorganic substrates where oxygen levels are low to avoid predation and to explore other food sources. Their anoxic tolerance also allows them to survive at times where low water levels lead to a quick depletion of oxygen, but as they are sensitive to desiccation, or drying out, they cannot survive for extended periods without water.
Water has been detected in interstellar clouds within our galaxy, the Milky Way. Water probably exists in abundance in other galaxies, too, because its components, hydrogen and oxygen, are among the most abundant elements in the universe. Based on models of the formation and evolution of the Solar System and that of other star systems, most other planetary systems are likely to have similar ingredients.
Unlike kangaroos and eucalyptus-eating possums, koalas are hindgut fermenters, and their digestive retention can last for up to 100 hours in the wild, or up to 200 hours in captivity. This is made possible by the extraordinary length of their caecum— long and in diameter—the largest proportionally of any animal. Koalas can select which food particles to retain for longer fermentation and which to pass through. Large particles typically pass through more quickly, as they would take more time to digest. While the hindgut is proportionally larger in the koala than in other herbivores, only 10% of the animal's energy is obtained from fermentation. Since the koala gains a low amount of energy from its diet, its metabolic rate is half that of a typical mammal, although this can vary between seasons and sexes. The koala conserves water by passing relatively dry faecal pellets high in undigested fibre, and by storing water in the caecum.
Humans evolved to live as simple hunter-gatherers in small tribal bands. Contemporary humans now have a very different environment and way of life. This change makes present humans vulnerable to a number of health problems, termed "diseases of civilization" and "diseases of affluence". Stone-age humans evolved to live off the land, taking advantage of the resources that were readily available to them. Evolution is slow, and the rapid change from stone-age environments and practices to the world of today is problematic because we are still adapted to stone-age circumstances that no longer apply. This misfit has serious implications for our health. "Modern environments may cause many diseases such as deficiency syndromes like scurvy and rickets".)
During the winter and early spring, horses lose about 30% of their body weight. They must regain this weight during summer and fall so as to survive another year. During particularly hard winters ("zuds"), horses may starve to death en masse or die of exposure. Herdsmen can do little to save their herds in such conditions. In the bitter winter of 2009 - 2010, 188,270 Mongol horses perished. Despite their life in semi-feral conditions, most horses live to be 20 – 40 years old.
The length of the small intestine can vary greatly, from as short as to as long as , also depending on the measuring technique used. The typical length in a living person is 3m-5m. The length depends both on how tall the person is and how the length is measured. Taller people generally have a longer small intestine and measurements are generally longer after death and when the bowel is empty.
Human magnetism is a popular name for an alleged ability of some people to attract objects to their skin. People alleged to have such an ability are often called human magnets. Although metal objects are the most popular, some are also alleged to be able to stick other types of materials, such as glass, porcelain, wood or plastic as well as metals with no ferromagnetic properties such as brass and aluminum. In fact none of the recorded claims of human magnetism corresponds with the actual physics of magnetism, indicating that this "ability" is in fact nothing more than a misunderstanding of the physics and meaning of the term and a misapplication of it to what has been shown to be nothing more than unusually sticky skin.According to scientists, if people can stick objects to their body, not only metal but also other materials, it has actually nothing to do with magnetism. Skeptic Benjamin Radford has used a compass to check the magnetic field of a person that claimed to be a human magnet. He claims that person didn't actually produce magnetic fields. It shows that human magnetism uses different kinds of physical effects. Many scientists and proponents of science, including James Randi, claim that this ability is caused by sticky skin.
Some wildlife centers housing captive wolves prohibit handlers from entering wolf enclosures if they happen to have a cold or other vulnerability which the wolves can detect. Captive wolves are generally shy and avoid eye contact with humans other than their owner, as well as not listening to any commands made by any other humans. They usually vacate rooms or hide when a new person enters the establishment. Even seemingly friendly wolves need to be treated with caution, as captive wolves tend to view and treat people as other wolves, and will thus bite or dominate people in the same situation in which they would other wolves. Ordinary pet food is inadequate, as an adult wolf needs 1–2.5 kg (2–5 lbs) of meat daily along with bones, skin and fur to meet its nutritional requirements. Wolves may defend their food against people, and react violently to people trying to remove it. The exercise needs of a wolf exceed the average dog's demand. Because of this, captive wolves typically do not cope well in urban areas. Due to their talent at observational learning, adult captive wolves can quickly work out how to escape confinement, and require constant reinforcement by caretakers or owners, which makes raising wolves difficult for people who raise their pets in an even, rather than subordinate, environment.
Contrasted to other carnivorous mammals known to attack humans for food, the frequency with which wolves have been recorded to kill people is rather low, indicating that, though potentially dangerous, wolves are among the least threatening for their size and predatory potential, except for the dog which poses lethal hazards for reasons other than predation. In the rare cases in which man-eating wolf attacks occur, the majority of victims are children. Habituation is a known factor contributing to some man-eating wolf attacks which results from living close to human habitations, causing wolves to lose their fear of humans and consequently approach too closely, much like urban coyotes. Habituation can also happen when people intentionally encourage wolves to approach them, usually by offering them food, or unintentionally, when people do not sufficiently intimidate them. This is corroborated by accounts demonstrating that wolves in protected areas are more likely to show boldness toward humans than ones in areas where they are actively hunted.Attacks on humans by dingoes are rare, with only two recorded fatalities in Australia. Dingoes are normally shy of humans and avoid encounters with them. The most famous record of a dingo attack was the disappearance of nine-week-old Azaria Chamberlain. Her parents reported that they both saw a dingo taking Azaria out of their tent when she and her family were out on a camping trip to Uluru.
Swimming in the pool at the bottom of the falls is discouraged. This is due both to occasional rockfalls and to the bacterial disease called Leptospirosis, which causes severe flu-like symptoms. Leptospirosis is found in freshwater and is common in tropical climates. In Hawaii, rats and mice often carry the disease and can easily transfer it to humans through their urine.
As of , the oldest known living person is Kane Tanaka of Japan, aged . The oldest known living man is Gustav Gerneth of Germany, aged . Due to differences in life expectancy, the 100 oldest women have lived significantly longer than the 100 oldest men.
Ahmed Gabr (أحمد جبر in Arabic; born 9 November 1972) is an Egyptian scuba diver who holds the Guinness World Records for both The Deepest Scuba Dive (Male) and The Deepest Scuba Dive in Sea Water. Ahmed dived to a depth of .In 2010, Gabr started training to break the world's record for the deepest depth ever reached by a human in scuba diving. The holder of the previous record was Nuno Gomes, with a record of 1,044 feet (318.25 m). Initially, the dive was scheduled to be done in 2012, but due to some political unrest in Egypt the dive was postponed.
Blue wildebeest are mainly found in short-grass plains bordering bush-covered acacia savannas in southern and eastern Africa, thriving in areas that are neither too wet nor too arid. They can be found in habitats that vary from overgrazed areas with dense bush to open woodland floodplains. Trees such as "Brachystegia" and "Combretum" spp. are common in these areas. Blue wildebeest can tolerate arid regions as long as a potable water supply is available, normally within about distance. The southern limit of the blue wildebeest stops at the Orange River, while the western limit is bounded by Lake Victoria and Mount Kenya. The range does not include montane or temperate grasslands. These wildebeest are rarely found at altitudes over . With the exception of a small population of Cookson's wildebeest that occurs in the Luangwa Valley (Zambia), the wildebeest is absent in the wetter parts of the southern savanna country, and particularly is not present in miombo woodlands.
A crash is usually felt within four hours or less of heavy carbohydrate consumption. Symptoms of reactive hypoglycemia include:
Although they are social animals, they are usually solitary or found in pairs due to the inability of seagrass beds to support large populations. Gatherings of hundreds of dugongs sometimes happen, but they last only for a short time. Because they are shy, and do not approach humans, little is known about dugong behaviour. They can go six minutes without breathing (though about two and a half minutes is more typical), and have been known to rest on their tail to breathe with their heads above water. They can dive to a maximum depth of ; they spend most of their lives no deeper than . Communication between individuals is through chirps, whistles, barks, and other sounds that echo underwater. Different sounds have been observed with different amplitudes and frequencies, implying different purposes. Visual communication is limited due to poor eyesight, and is mainly used for activities such as lekking for courtship purposes. Mothers and calves are in almost constant physical contact, and calves have been known to reach out and touch their mothers with their flippers for reassurance.
At the beginning of the 1990s, some Japanese manufacturers started the development of a new, low-ohmic water-based class of electrolytes. Water, with its high permittivity of ε = 81, is a powerful solvent for electrolytes, and possesses high solubility for conductivity-enhancing concentrations of salt ions, resulting in significantly improved conductivity compared to electrolytes with organic solvents like GBL. But water will react quite aggressively and even violently with unprotected aluminum, converting metallic aluminum (Al) into aluminum hydroxide (Al(OH)), via a highly exothermic reaction that gives off heat, causing gas expansion that can lead to an explosion of the capacitor. Therefore, the main problem in the development of water-based electrolytes is achieving long-term stability by hindering the corrosive action of water on aluminum.
There is disagreement among experts as to what would be considered a realistic poverty rate with one considering it "an inaccurately measured and arbitrary cut off". Some contend that a higher poverty line is needed, such as a minimum of $7.40 or even $10 to $15 a day. They argue that these levels would better reflect the cost of basic needs and normal life expectancy. One estimate places the true scale of poverty much higher than the World Bank, with an estimated 4.3 billion people (59% of the world's population) living with less than $5 a day and unable to meet basic needs adequately. It has been argued by some academics that the neoliberal policies promoted by global financial institutions such as the IMF and the World Bank are actually exacerbating both inequality and poverty.
Vulcans are typically depicted as stronger, faster, and longer-lived than humans (although discrepancies have occurred—and although not as long as Vulcans, humans have been shown to live longer in the Star Trek universe than today—presumably as the result of advances in medical science). Vulcans are about three times as strong as an average human because of their home planet's higher gravity, although their durability is equal to humans. There are instances of them living over two hundred and twenty years. Having evolved on a desert world, Vulcans can survive without water for longer periods than humans. Vulcans can also go without sleep for as long as two weeks. Romulans are similar in appearance to Vulcans, with whom they share a common ancestry; they even appear almost identical on Starfleet sensors, with just a minute difference between them ("The Enterprise Incident").
During the event, for 30 hours, participants must abstain from eating food, and instead they typically drink water, fruit juices, or other liquids Games, fund raisers, and other events may also take place to help teach and educate the participants and others about world hunger all over the world. It is also a time for education and awareness of world hunger, and an understanding of how people go without food for long periods of time. This, however, does not exclude those unable to fast.
Human survival on Mars would require living in artificial Mars habitats with complex life-support systems. One key aspect of this would be water processing systems. Being made mainly of water, a human being would die in a matter of days without it. Even a 5–8% decrease in total body water causes fatigue and dizziness and a 10% decrease physical and mental impairment (See Dehydration). A person on Earth uses 70–140 litres of water per day on average. Through experience and training, astronauts on the ISS have shown it is possible to use far less, and that around 70% of what is used can be recycled using the ISS water recovery systems. Similar systems would be needed on Mars, but would need to be much more efficient, since regular robotic deliveries of water to Mars would be prohibitively expensive (the ISS is supplied with water four times per year). Some experts have argued for setting up open-air settlements by using special construction methodologies- like excavating deep into the Martian crust to depths where air pressures may be sufficient to allow humans to survive without pressurized suits.Potential access to in-situ water (frozen or otherwise) via drilling has been investigated by NASA.
Examples are: Some breeds of dog swim recreationally. Umbra, a world record-holding dog, can swim 4 miles (6.4 km) in 73 minutes, placing her in the top 25% in human long-distance swimming competitions. Although most cats hate water, adult cats are good swimmers. The fishing cat is one wild species of cat that has evolved special adaptations for an aquatic or semi-aquatic lifestyle – webbed digits. Tigers and some individual jaguars are the only big cats known to go into water readily, though other big cats, including lions, have been observed swimming. A few domestic cat breeds also like swimming, such as the Turkish Van.