Extreme Cold Ebook
Assistive technology (AT) is anything scientifically or technically manufactured that serves to assist or improve normal function. It can include manufactured items that serve humans, ranging from clothing that enhances functioning in cold weather to airplanes that speed movement from one place to another. The term is not restricted to its use by people with disabilities (PWDs) for technological devices or programs that are useful to them. However, the field of rehabilitation of people with physical or sensory disabilities has co-opted the term to some extent to refer to utilization by PWDs without actually defining the nature or the extent of the disability. Thus the term, as used in rehabilitation, includes all types of devices and programs, regardless of
The threat posed by lice is not only associated to the louse infestation considered as a disease in itself known as pediculosis. Indeed, the human body lice, Pediculus humanus humanus, or P. h. corporis (Fig. 3), are recognized as vectors of three human infections that are reemerging epidemic typhus, relapsing fever (caused by Borrelia recurrentis) and trench fever (caused by Bartonella quintana). Only the human body lice can transmit human pathogens. They live in clothes and multiply when conditions such as cold weather, lack of hygiene, or war are present. Its prevalence reflects the socioeconomic level of the society (52). Currently, the infestation by the human body louse is reemerging, and it is increasingly described in the poorest populations of developed and industrialized countries (26-29).
The potential for confounding in time-series regression is very high - many variables either simply increase or decrease over time, and so will be correlated over time.9 In addition many epidemiological variables are seasonal, and this variation would be present even if the factors were not causally related. It is important that seasonality and trends are properly accounted for. Simply because the outcome variable is seasonal, it is impossible to ascribe causality because of seasonality of the predictor variable. For example, sudden infant deaths are higher in winter than in summer, but this does not imply that temperature is a causal factor there are many other factors that might affect the result such as reduced daylight, or presence of viruses. However, if an unexpectedly cold winter is associated with an increase in sudden infant deaths, or very cold days are consistently followed after a short time by rises in the daily sudden infant death rate, then causality may possibly be...
A heart attack occurs when the blood vessels supplying the heart muscle become blocked, starving it of oxygen, leading to the heart muscle's failure or death. Heart attack has the same risk factors as CVD in general. Cold weather, exercise, or strong emotion can precipitate a heart attack.
Exposure of animals to extreme cold for several weeks can cause their thyroid glands to increase in size 20 to 40 per cent. However, human beings seldom allow themselves to be exposed to the same degree of cold as that to which animals are often subjected. Therefore, we still do not know, quantitatively, how important the thyroid mechanism of adaptation to cold is in the human being.
The General Adaptation Syndrome (GAS) is a cluster of bodily responses to severe, prolonged stressors that was described by Hans Selye. Selye observed that rats exposed to a wide variety of noxious agents exhibited a nonspecific syndrome consisting of enlargement of the adrenal cortex shrinkage of the thymus, spleen, and lymph glands and the appearance of ulcers in the stomach and small intestine. This response was seen in animals exposed to extreme cold and heat, intense sound or light, forced exercise, injections of various organ extracts or formalin, or a variety of other intense biological challenges to normal homeostatic function. Selye suggested that the GAS consisted of three phases of response to a stressor. The initial stage consisted of an alarm reaction during which the adrenal cortex enlarged and released large amounts of the adrenoglucocorticoid hormone cortisol into the bloodstream, the lymphatic tissues shrunk, the number of white blood cells declined, the...
Insensible water loss through the respiratory tract averages about 300 to 400 ml day. As air enters the respiratory tract, it becomes saturated with moisture, to a vapor pressure of about 47 mm Hg, before it is expelled. Because the vapor pressure of the inspired air is usually less than 47 mm Hg, water is continuously lost through the lungs with respiration. In cold weather, the atmospheric vapor pressure decreases to nearly 0, causing an even greater loss of water from the lungs as the temperature decreases. This explains the dry feeling in the respiratory passages in cold weather.
Croup syndromes occur worldwide, most caused by common croup viruses parainfluenzas 1 and 2 and influenza viruses. Outbreaks occur during cold-weather months, and in the tropics during rainy seasons. The highest attack rate occurs in children 7-36 months old few cases occur after the sixth birthday. During their second year, about 5 percent of children experience an episode of croup. Croup is more common in boys than in girls and also tends to be more severe in boys. A parainfluenza infection in an adult is manifested by a cold older persons suffering trivial illnesses may be the source of severe croup in young children.
The etiology of Achilles tendon overuse injuries is multifactorial.24,27 These studies are mainly retrospective, and report statistical association between the condition and several factors. A direct cause-effect relationship has been demonstrated by very few studies. Training errors like running too long, at too high an intensity, increasing the training distance too greatly or the intensity too rapidly, and performing too much uphill or downhill work4,20,27 have been reported in two-thirds of the running injuries.21,28 Monotonous, asymmetric, and specialized training, such as running only (i.e., without cross-training), as well as poor technique and fatigue are further risk factors for Achilles tendon overuse injuries.27 Poor environmental conditions such as cold weather, hard ground surface, and slippery icy surface have also been suggested to promote Achilles tendon problems.28-30
GAS may be brought about by any stressful situation, including chronic physical stress (e.g., from exposure to extreme cold or in times of real physical danger), but it also may occur as a result of continual psychological stress. As originally described by Selye, the physical correlates of GAS include enlarged adrenal glands, with a marked increased in size of the adrenal cortex as its cells respond to the actions of ACTH and attempt to produce ever larger quantities of the glucocorticoids, as well as a shrunken thymus, weight loss, and gastric ulcers. Gastric ulcers are caused by chronic decrease in blood flow to the gut. Substantial rates of blood flow are necessary for maintenance of the mucosal lining that protects the stomach from the digestive acids. As a consequence of chronic activation of the body's stress response, the gut's blood flow is so decreased that its mucosal lining deteriorates, and the stomach's hydrochloric acid produces ulcers.
The maintenance of a unialgal population of Arthrospira in outdoor ponds requires a good understanding of the physiology and ecology of the algae. Optimization of the productivity and quality of the culture requires the appropriate climatic environment, pond design, chemistry, and routine monitoring to fit the physiological and ecological requirements of the algae. Even though the medium used for growing Spirulina prevents contamination by other algae owing to its high pH and alkalinity, suboptimal operation of the culture control process can lead to contamination by other algae. This is particularly true during the scale-up process when the biomass concentration of Arthrospira is low. However, this problem is surmounted through careful manipulation of the nutrient content and through an ecosystem approach. Culture can be scaled up either from laboratory culture or from culture overwintered in green house or open ponds. The latter makes the expansion process a lot faster. However, not...
This disorder usually begins in childhood, and patients often have difficulty in keeping up with their peers in physical activities. They have poor relaxation of muscles, initially in the limbs but later in the face and trunk as well. This pseudomyotonia is made worse by exercise and cold weather, and myoglobinuria occurs in some. On examination, these patients are found to have eyelid and grip but not percussion myotonia. There may be mild muscle atrophy and weakness in the final stages of the disease.
Myopathy can be a feature of hypothyroidism and manifests with proximal muscle weakness. Regardless of the cause of the hypothyroidism, weakness is observed in about one third of these patients.y Increased muscle size and firmness, which is most obvious in the limb musculature, as well as slowed muscle contraction are important features to identify. Exertional pain, stiffness, and cramps may be noted, and myoedema may be observed. Myoedema, a mounding of the muscle in response to direct percussion, is painless and electrically silent, and occurs in one third of hypothyroid patients. y Difficulty relaxing the hand grip and exacerbation by cold weather may suggest myotonia. However, unlike myotonia, hypothyroid myopathy involves a slowness of muscle relaxation and contraction, and resolves with correction of the hypothyroid state. y Although sleep apnea is usually of the obstructive type, other possibilities include a central abnormality, chest muscle weakness, and blunted responses to...
Planting is carried out in autumn (October-November) or early spring (end of February-March). Autumn planting is more preferable, since a better plant establishment is promoted, except in areas with very cold winters. The choice of the most appropriate plant spacing strongly depends on local conditions (soil fertility, climatic conditions, weeds) and varies from 50 to 60x25 to 40 cm. Denser crops (35x15 cm) have also been successful (Putievski et al., 1986a). On the other hand, wider spacings have been reported (100 cm-apart rows) for seed propagating crops (Macchia et al., 1988). Denser stands reduce the numbers of primary and secondary stems as well as plant dry matter production (ibid.).
Cool deserts are characterized by cold winters with much snow and rain falling during the winter and occasionally over the summer. In the United States they are found along the western edge of the Great Plains. Cool deserts have short, moist, moderately warm summers with fairly long, cold winters. The mean temperature in winter is between -2 C (28 F) and 4 C (39 F) in summer, between 21 C (70 F) and 26 C (79 F). The mean annual precipitation ranges from 15 cm to 26 cm (6-10 inches). The heaviest rainfall of the spring is usually in April or May. Rainfall is also heavy in autumn in some areas.
Dry irritated skin occurs frequently in occupational settings, where different types of irritants - physical, chemical and mechanical - separately, con-comitantly or sequentially disturb the epidermal barrier. Further, humidity is an independent risk factor for irritant hand dermatitis 15 the importance of several meteorological factors (day means of temperature, relative and absolute humidity) was assessed in 742 hairdressing apprentices. An increased prevalence of irritant skin changes was noted during particularly cold winter months with low temperature and low absolute humidity. In winter dry skin degradation of corneodesmosomes has been found to be abnormal compared to normal controls 6 the amounts of corneodesmosin, desmoglein 1 and plakoglobin detected were significantly higher in winter dry skin compared with normal skin extracts. Furthermore, during the cold winter months, risk factors for the development of occupational irritant hand dermatitis are increased 15 . Further,...
In 1925, Cannon described his findings as instances of the maintenance of steady states in open systems. In 1926 he named this steady condition homeostasis and offered a set of postulates regarding its nature. In 1929, he discussed the homeostatic regulatory mechanisms identified up to that point. The body, he asserted, was able through home-ostatic reactions to maintain stability in the fluid matrix surrounding the body cells, thus controlling body temperature, blood pressure, and other aspects of the internal environment necessary for life. Regulated by the nervous system and endocrine glands, bodily reactions at all levels of complexity were involved in homeostasis, from the speed with which cell metabolism proceeded and produced heat in cold weather, to increases and decreases in the complex processes giving rise to hunger and thirst, with impact on behaviors affecting energy and water intake.