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Oxygen-deficient Atmosphere
Inert gas asphyxiation is a form of asphyxiation which results from breathing a physiologically inert gas in the absence of oxygen, or a low amount of oxygen (hypoxia), rather than atmospheric air (which is composed largely of nitrogen and oxygen). Examples of physiologically inert gases, which have caused accidental or deliberate death by this mechanism, are argon, helium and nitrogen. The term "physiologically inert" is used to indicate a gas which has no toxic or anesthetic properties and does not act upon the heart or hemoglobin. Instead, the gas acts as a simple diluent to reduce the oxygen concentration in inspired gas and blood to dangerously low levels, thereby eventually depriving cells in the body of oxygen. According to the U.S. Chemical Safety and Hazard Investigation Board, in humans, "breathing an oxygen deficient atmosphere can have serious and immediate effects, including unconsciousness after only one or two breaths. The exposed person has no warning and cannot s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asphyxiation
Asphyxia or asphyxiation is a condition of deficient supply of oxygen to the body which arises from abnormal breathing. Asphyxia causes generalized hypoxia, which affects all the tissues and organs, some more rapidly than others. There are many circumstances that can induce asphyxia, all of which are characterized by the inability of a person to acquire sufficient oxygen through breathing for an extended period of time. Asphyxia can cause coma or death. In 2015, about 9.8 million cases of unintentional suffocation occurred which resulted in 35,600 deaths. The word asphyxia is from Ancient Greek "without" and , "squeeze" (throb of heart). Causes Situations that can cause asphyxia include but are not limited to: airway obstruction (such as from asthma, laryngospasm, or simple blockage from the presence of foreign materials); from being in environments where oxygen is not readily accessible: such as underwater, in a low oxygen atmosphere, or in a vacuum; environments where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Respiration (physiology)
In physiology, respiration is the transport of oxygen from the outside environment to the Cell (biology), cells within Tissue (biology), tissues, and the removal of carbon dioxide in the opposite direction to the environment by a respiratory system. The physiological definition of respiration differs from the Cellular respiration, biochemical definition, which refers to a metabolic process by which an organism obtains energy (in the form of ATP and NADPH) by oxidizing nutrients and releasing waste products. Although physiologic respiration is necessary to sustain cellular respiration and thus life in animals, the processes are distinct: cellular respiration takes place in individual cells of the organism, while physiologic respiration concerns the Diffusion#Diffusion vs. bulk flow diffusion, diffusion and transport of metabolites between the organism and the external environment. Exchange of gases in the lung occurs by ventilation and perfusion. Ventilation refers to the in-and-ou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STS-1
STS-1 (Space Transportation System-1) was the first orbital spaceflight of NASA's Space Shuttle program. The first orbiter, ''Columbia'', launched on April 12, 1981, and returned on April 14, 1981, 54.5 hours later, having orbited the Earth 37 times. ''Columbia'' carried a crew of two—commander John W. Young and pilot Robert L. Crippen. It was the first American crewed space flight since the Apollo–Soyuz Test Project (ASTP) in 1975. STS-1 was also the maiden test flight of a new American spacecraft to carry a crew, though it was preceded by atmospheric testing (ALT) of the orbiter and ground testing of the Space Shuttle system. The launch occurred on the 20th anniversary of Vostok 1, the first human spaceflight, performed by Yuri Gagarin for the USSR. This was a coincidence rather than a celebration of the anniversary; a technical problem had prevented STS-1 from launching two days earlier, as was planned. Crew Commander John Young and pilot Robert Crippen were sel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Euthanasia
Animal euthanasia (euthanasia from ; "good death") is the act of killing an animal humanely, most commonly with injectable drugs. Reasons for euthanasia include incurable (and especially painful) conditions or diseases, lack of resources to continue supporting the animal, or laboratory test procedures. Euthanasia methods are designed to cause minimal pain and distress. Euthanasia is distinct from animal slaughter and pest control. In domesticated animals, the discussion of animal euthanasia may be substituted with euphemisms, such as "put down" or "put to sleep" to make the wording less harsh. Methods The methods of euthanasia can be divided into pharmacological and physical methods. Acceptable pharmacological methods include injected drugs and gases that first depress the central nervous system and then cardiovascular activity. Acceptable physical methods must first cause rapid loss of consciousness by disrupting the central nervous system. The most common methods are discus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asphyxiant Gas
An asphyxiant gas, also known as a simple asphyxiant, is a nontoxic or minimally toxic gas which reduces or displaces the normal oxygen concentration in breathing air. Breathing of oxygen-depleted air can lead to death by asphyxiation (suffocation). Because asphyxiant gases are relatively inert and odorless, their presence in high concentration may not be noticed, except in the case of carbon dioxide ( hypercapnia). Toxic gases, by contrast, cause death by other mechanisms, such as competing with oxygen on the cellular level (e.g. carbon monoxide) or directly damaging the respiratory system (e.g. phosgene). Far smaller quantities of these are deadly. Notable examples of asphyxiant gases are methane, nitrogen, argon, helium, butane and propane. Along with trace gases such as carbon dioxide and ozone, these compose 79% of Earth's atmosphere. Asphyxia hazard Asphyxiant gases in the breathing air are normally not hazardous. Only where elevated concentrations of asphyxiant g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cane Toads In Australia
The cane toad in Australia is regarded as an exemplary case of an invasive species. Australia's relative isolation prior to History of Australia (1788–1850), European colonisation and the Industrial Revolution, both of which dramatically increased traffic and import of novel species, allowed development of a complex, interdepending system of ecology, but one which provided no natural predators for many of the species subsequently introduced. The sudden inundation of foreign species has led to severe breakdowns in Australian ecology, after overwhelming proliferation of a number of introduced species, for which the continent has no efficient natural predators or parasites, and which displace native species; in some cases, these species are physically destructive to habitat, as well. Cane toads have been very successful as an invasive species, having become established in more than 15 countries within the past 150 years. In the Environment Protection and Biodiversity Conservati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poultry
Poultry () are domesticated birds kept by humans for the purpose of harvesting animal products such as meat, Eggs as food, eggs or feathers. The practice of animal husbandry, raising poultry is known as poultry farming. These birds are most typically members of the superorder Galloanserae (fowl), especially the order Galliformes (which includes chickens, quails, and domestic turkey, turkeys). The term also includes waterfowls of the family Anatidae (ducks and geese) but does not include wild birds hunted for food known as game (hunting), game or wild meat, quarry. Recent genomic studies involving the four extant junglefowl species reveals that the domestication of chicken, the most populous poultry species, occurred around 8,000 years ago in Southeast Asia. This was previously believed to have occurred around 5,400 years ago, also in Southeast Asia. The process may have originally occurred as a result of people hatching and rearing young birds from eggs collected from the wild, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swine
Suina (also known as Suiformes) is a suborder of omnivorous, non-ruminant artiodactyl mammals that includes the domestic pig and peccaries. A member of this clade is known as a suine. Suina includes the family Suidae, termed suids, known in English as pigs or swine, as well as the family Tayassuidae, termed tayassuids or peccaries. Suines are largely native to Africa, South America, and Southeast Asia, with the exception of the wild boar, which is additionally native to Europe and Asia and introduced to North America and Australasia, including widespread use in farming of the domestic pig subspecies. Suines range in size from the 55 cm (22 in) long pygmy hog to the 210 cm (83 in) long giant forest hog, and are primarily found in forest, shrubland, and grassland biomes, though some can be found in deserts, wetlands, or coastal regions. Most species do not have population estimates, though approximately two billion domestic pigs are used in farming, while ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stunning
Stunning is the process of rendering animals immobile or unconscious, with or without killing the animal, when or immediately prior to slaughtering them for food. Rationale Within the European Union, most animals slaughtered for human consumption are killed by cutting major blood vessels in the neck or thorax so that rapid blood loss occurs. After a certain degree of blood loss has occurred, the animal will become unconscious, and after a greater blood loss death will ensue. From the moment of cutting until the loss of consciousness, the animal experiences pain, stress, and fear. Without stunning, the time between cutting through the major blood vessels and insensibility, as deduced from behavioural and brain response, is up to 20 seconds in sheep, up to 25 seconds in pigs, up to 2 minutes in cattle, up to 2.5 or more minutes in poultry, and sometimes 15 minutes or more in fish. If one seeks to minimise animal suffering in slaughter, stunning is necessary. The best stunning me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAF Institute Of Aviation Medicine
The Royal Air Force Institute of Aviation Medicine was a Royal Air Force aviation medicine research unit active between 1945 and 1994. Early days The RAF Institute of Aviation Medicine (IAM) was opened on 30 April 1945 by the Princess Royal. It was located on land to the south side of the Farnborough Airfield in Hampshire, and was successor to the wartime RAF Physiological Laboratory. Initially having separate sections for acceleration, altitude, biochemistry, biophysics, personal equipment and teaching, its mandate was to conduct both pure and applied research in support of flying personnel. Initially run by Dr Bryan Matthews, Group Captain Bill Stewart was appointed head in 1946. A former pupil of the Hamilton Academy school, Stewart was to be promoted to Air Vice-Marshal, and awarded CB and CBE. The Stewart Lecture at the Royal Aeronautical Society was established in his memory in 1969. The IAM obtained a decompression chamber (moved from the Physiological Laborator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanosis
Cyanosis is the change of Tissue (biology), tissue color to a bluish-purple hue, as a result of decrease in the amount of oxygen bound to the hemoglobin in the red blood cells of the capillary bed. Cyanosis is apparent usually in the Tissue (biology), body tissues covered with thin skin, including the mucous membranes, lips, nail beds, and ear lobes. Some medications may cause discoloration such as medications containing amiodarone or silver. Furthermore, mongolian spots, large birthmarks, and the consumption of food products with blue or purple dyes can also result in the bluish skin tissue discoloration and may be mistaken for cyanosis. Appropriate physical examination and history taking is a crucial part to diagnose cyanosis. Management of cyanosis involves treating the main cause, as cyanosis is not a disease, but rather a symptom. Cyanosis is further classified into central cyanosis and peripheral cyanosis. Pathophysiology The mechanism behind cyanosis is different dep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rebreather
A rebreather is a breathing apparatus that absorbs the carbon dioxide of a user's exhaled breath to permit the rebreathing (recycling) of the substantial unused oxygen content, and unused inert content when present, of each breath. Oxygen is added to replenish the amount metabolised by the user. This differs from open-circuit breathing apparatus, where the exhaled gas is discharged directly into the environment. The purpose is to extend the breathing endurance of a limited gas supply, while also eliminating the bubbles otherwise produced by an open circuit system. The latter advantage over other systems is useful for covert military operations by frogmen, as well as for undisturbed observation of underwater wildlife. A rebreather is generally understood to be a portable apparatus carried by the user. The same technology on a vehicle or non-mobile installation is more likely to be referred to as a life-support system. Rebreather technology may be used where breathing gas supp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
