Physiological reactions to cold of Bushmen, Bantu, and Caucasian males

1964 ◽  
Vol 19 (5) ◽  
pp. 868-876 ◽  
Author(s):  
C. H. Wyndham ◽  
J. F. Morrison ◽  
J. S. Ward ◽  
G. A. G. Bredell ◽  
M. J. E. Von Rahden ◽  
...  
Keyword(s):  
Heat Flow ◽  
Subcutaneous Tissue ◽  
Natural Habitat ◽  
Metabolic Rates ◽  
The Difference ◽  
Tissue Insulation ◽  
Physiological Reactions ◽  
Average Skin ◽  
Skin Temperatures ◽  
Made In

Two separate studies of the reactions to cold of one sample of 8 and one sample of 15 Kalahari Bushmen were made in their natural habitat and the results compared with the Bantu and, to a smaller extent, with the Caucasians. With a decrease in temperature from 27 to 5 C the metabolisms of all three groups rose. Metabolic rates per square meter of Bantu and Bushmen were similar, although higher than those of the Caucasians, but the percentage increases were closely similar for all groups. Rectal temperatures of Bushmen and Bantu were similar and decreased as the temperature dropped, while that of the Caucasians rose. Toe and finger temperatures of the Bushmen were higher over the whole temperature range than those of the Bantu and Caucasians, while the average skin temperatures were closely similar. Metabolic rates and rectal temperatures, therefore, indicate that subcutaneous tissue insulation against heat flow is greater for the Caucasians than for the Bantu or the Bushmen. Measurements of average skinfold thicknesses confirm this finding. Bushmen and Bantu reactions are quantitatively similar, but are qualitatively slightly different. From these findings we conclude that the difference between Bushmen, Bantu, and Caucasians is essentially morphological. desert and "river" Bushmen in the heat; effect of morphology on reaction to heat; heat reactions of Bantu and Bushmen; state of acclimatization to heat of Bushmen and Bantu; sweat rates of Bantu and Bushmen in standard heat conditions Submitted on October 21, 1963

Physiological reactions of Caucasian and Bantu males in acute exposure to cold

1964 ◽  
Vol 19 (4) ◽  
pp. 583-592 ◽  
Author(s):  
C. H. Wyndham ◽  
J. S. Ward ◽  
N. B. Strydom ◽  
J. F. Morrison ◽  
C. G. Williams ◽  
...  
Keyword(s):  
Body Temperature ◽  
Ethnic Differences ◽  
Metabolic Response ◽  
Climatic Chamber ◽  
Air Temperatures ◽  
Metabolic Reactions ◽  
The Difference ◽  
Physiological Reactions ◽  
Average Skin ◽  
Skin Temperatures

Eleven men per sample of Caucasian and Bantu males were exposed for 2 hr in a climatic chamber at various air temperatures ranging from 5 to 27 C, and a wind velocity of 80–100 ft/min. When expressed per square meter surface area the metabolism of the Bantu was greater in the range above 18 C and below 6 C. Average skin temperatures were similar for both groups, but between 27 and 17 C the toe and finger temperatures of the Caucasians were significantly higher than that of the Bantu—the difference at 27 C being 5 C for the fingers and 3.6 C for the toes. Rectal temperatures of both groups were similar between 27 and 17 C. With the rectal temperatures at 27 C air temperature as the criterion, it was found that as the air temperatures decreased below the 27–17 C range the rectal temperatures of the Bantu fell linearly, while the rectal temperatures of the Caucasians rose steadily. There is no doubt that in certain ranges of air temperatures there are significant differences between the cold reactions of Caucasians and the Bantu. cold adaptation; ethnic differences in response to cold; metabolic and body temperature reactions to cold; metabolic response to body temperature; metabolic reactions of ethnic groups Submitted on July 15, 1963

Physiological reactions to cold of men in the Antarctic

1964 ◽  
Vol 19 (4) ◽  
pp. 593-597 ◽  
Author(s):  
C. H. Wyndham ◽  
R. Plotkin ◽  
A. Munro
Keyword(s):  
South African ◽  
Cold Adaptation ◽  
Physiological Responses ◽  
Control Group ◽  
Climatic Chamber ◽  
Thermoneutral Zone ◽  
The Antarctic ◽  
Physiological Reactions ◽  
Average Skin ◽  
Skin Temperatures

The physiological reactions to cold of five members of the 1961–1962 South African expedition to the Antarctic were studied in a climatic chamber in Johannesburg, and again after 6 months and after 12 months in the Antarctic. Their results were compared with the results of a control group in Johannesburg. The predeparture results were within the 95% significance intervals of the control group. After 12 months in the Antarctic their results fell outside the 95% significance intervals of the control group when at 5 C air temperature, metabolism, average skin temperatures, rectal temperatures, and finger temperatures were all significantly lower. Toe temperatures, however, were higher. There appeared to be a gradual “adaptation” and general “toughening” to the cold, because the subjects shed their clothing progressively until they could run about naked in the snow. The values at the thermoneutral zone of 27 C did not change over the 12 months, however. It is therefore concluded that it is unlikely that the changes in physiological responses were of endocrine origin. cold adaptation in Antarctic; metabolic and body temperature reactions to cold Submitted on August 16, 1963

Movement of nutrients in fungi. I. The Mycelium

1968 ◽  
Vol 16 (1) ◽  
pp. 71 ◽  
Author(s):  
LB Thrower ◽  
SL Thrower
Keyword(s):  
Nutrient Medium ◽  
Natural Habitat ◽  
Taxonomic Position ◽  
Deficient Medium ◽  
The Difference ◽  
Hyphal Apex

Thirty-one species of fungi (representing 13 orders) were examined for their ability to grow from a nutrient medium onto a non-nutrient medium; 17 were capable of colonizing the deficient medium, 10 were not, and 4 were indeterminate. The ability to grow onto deficient medium appeared to be related to the natural habitat of the fungus rather than to taxonomic position. Experiments with isotopically labelled nutrients showed that both colonizing fungi and non-colonizing fungi were capable of some transport of nutrients, the difference between the two groups being one of degree. In transporting fungi, labelled nutrients were moved more rapidly when the fungus colonized a deficient medium than when it colonized a nutrient medium; this suggested that movement of nutrients is adaptive to some extent. The importance of the growing hyphal apex as a sink for nutrients was demonstrated.

scholarly journals XIX. On the difference of meridians of the Royal Observatories of Greenwich and Paris

1827 ◽  
Vol 117 ◽  
pp. 286-296 ◽  
Keyword(s):  
The Other ◽  
Detailed Account ◽  
Sidereal Time ◽  
Methods Of Calculation ◽  
Royal Observatory ◽  
The Difference ◽  
Made In

In the Philosophical Transactions for 1826, Part II. Mr. Herschel has given a detailed account of observations, which were made in the month of July, 1825, for the purpose of ascertaining the difference of the meridians of the Royal Observatories of Greenwich and Paris, with a computation of these observations, from which the most probable value of the difference of longitude appears to be 9 m 21 s. 6. But I have perceived that in the copy of the observations delivered to him from the Royal Observatory of Greenwich, an error of one second has been committed; as the true sidereal time of the observation made there on 21st July, ought to be 17 h 38 m 57·12 in place of 17 h 38 m 56 s. 10, set down in the Table p. 104, which he informs me was computed at the Observatory, and officially communicated to him from the Astronomer Royal. This error seems to have had its origin in the little Table at the bottom of page 103; for, on subtracting the error of the clock, 47 s. 37, from the time 18 h 8 m 30 s. 40, the true sidereal time is 18 h 7 m 43 s. 03, instead of 18 h 7 m 42 s. 03, there given. The error in the result of that day’s observations, arising from this cause, has been partly compensated by a mistake of three tenths of a second, which has occurred in calculating the combined observations of the same day, the gain of mean on sidereal time being stated to be — 4 s. 54 (pp. 120 and 122), in place of — 4 s. 24. On checking the other observations, a few trifling alterations appear to be necessary upon the Greenwich Table of sidereal time, from the data given along with it. These seem to be occasioned by different methods of calculation, and indeed are hardly worthy of notice. The French astronomers not having given the data on which the calculations of the sidereal times at Paris are founded, they are assumed to be correct.

Neural network processing of radar scanning data array

2021 ◽  
Author(s):  
V.E. Dmitriyev ◽  
D.V. Popov ◽  
V.A. Shakhnov
Keyword(s):  
Spatial Perception ◽  
Digital Processing ◽  
Radar Data ◽  
Information Value ◽  
Data Array ◽  
Additional Information ◽  
Distribution Of Values ◽  
The Difference ◽  
Radar Data Processing ◽  
Made In

This article deals with the digital processing of a matrix radar image. The information received from the radar scanner needs to be transformed to enable visual perception. The article describes the main methods of digital processing of matrix data, presents the images transformed by them. The aim of the article was the development of a radar data processing algorithm that identifies the contours and edges of examined objects. The authors propose an algorithm for isolating the geometric structure of the scanned area. The difference between the processing method and the known analogues is based on the nature of the change in the values of the array being processed and consists in the double operation of extracting the gradient of the distribution of values. The software implementation of the algorithm is made in C++ using methods from an open library of computer vision. The efficiency of the algorithm was estimated based on comparison with the algorithms for determining edges based on linear filtering and neural networks. The results of the work can be used to create software for mobile short-range radar devices. Imaging from object boundaries and their edges provides spatial perception of the image by the operator, and free areas are available for rendering additional information. This solution allows you to combine scanning devices and thereby increase the information value of the result.

Localizing cross-linguistic variation in Tense systems: On telicity and stativity in Swedish and English

2012 ◽  
Vol 35 (1) ◽  
pp. 27-70
Author(s):  
Björn Lundquist
Keyword(s):  
Romance Languages ◽  
Linguistic Variation ◽  
Verb Morphology ◽  
Reference Time ◽  
Lexical Aspect ◽  
Temporal Interpretation ◽  
Viewpoint Aspect ◽  
The Difference ◽  
Made In

It is well known that the aktionsart/lexical aspect of a predicate influences the temporal interpretation and the aspectual marking of a sentence, and also that languages differ with respect to which aktionsart properties feed into the tense-aspect system (see e.g. Bohnemeyer & Swift 2004). In this paper, I try to pin down the exact locus of variation between languages where the stative–dynamic distinction is mainly grammaticized (e.g. English, Saamáka) and languages where the telic–atelic distinction is mainly grammaticized (e.g. Swedish, Chinese and Russian). The focus will be on the differences between English and Swedish, and I will argue that these two languages crucially differ in the nature of Assertion Time (or Topic/Reference Time, Klein 1994, Demirdache & Uribe-Etxebarria 2000): whereas the assertion time in English is always punctual in imperfective contexts, assertion time in Swedish can extend to include minimal stages of events. The Assertion Time is introduced by a (viewpoint) aspect head that is present in both languages, but not phonologically realized. The difference can thus not be ascribed to the presence or absence of overt tense, aspect or verb morphology, or to a special tense value, as argued in one way or other by, for example, Giorgi & Pianesi (1997), Demirdache & Uribe-Etxebarria (2000) and Ramchand (2012). Once this factor (i.e. the nature of Assertion Time) has been isolated, it becomes evident that all verbs in English and Swedish, regardless of telicity or dynamicity, can be assigned either a perfective or an imperfective value. Moreover, I will argue that the English progressive–non-progressive (or ‘simple’) distinction is independent of viewpoint aspect (i.e. the perfective– imperfective distinction) made in, for example, the Romance languages.

Microangiopathy in Severe Chronic Venous Insufficiency Evaluated by Fluorescence Video-Microscopy

1986 ◽  
Vol 1 (3) ◽  
pp. 159-169 ◽  
Author(s):  
P. Haselbach ◽  
U. Vollenweider ◽  
G. Moneta ◽  
A. Bollinger
Keyword(s):  
Intravenous Injection ◽  
Chronic Venous Insufficiency ◽  
Venous Insufficiency ◽  
Subcutaneous Tissue ◽  
Flow Distribution ◽  
Skin Surface ◽  
Video Microscopy ◽  
Healthy Controls ◽  
Microvascular Flow ◽  
Made In

Fluorescence video microscopy after intravenous injection of Na-fluorescein was used to study capillary morphology, pericapillary halo diameters, microvascular flow distribution and transcapillary diffusion of the dye in 15 healthy controls and 15 patients with severe chronic venous insufficiency (CVI). The recordings were made in the medial ankle region. Transcapillary diffusion was monitored within a densitometer window encompassing 3.2 mm2 of skin surface. Microangiopathy known from previous studies was documented in the patients with severe CVI. The number of skin capillaries within the field of observation was not reduced. In some cases inhomogeneous microvascular flow distribution and probable microthrombosis were detected. Mean halo size averaged 81 — 15 μm in the controls and 146 ± 47 μm in the patients (P < 0.001). Unexpectedly, transcapillary diffusion of Na-fluorescein was not significantly increased in the field of measurement. Possible explanations include asynchronous inflow of the dye, the presence of thrombosed and therefore not perfused capillaries, a pericapillary fibrin layer limiting diffusion and redistribution of flow in favour of the subcutaneous tissue.

scholarly journals XXXIV. Observations on the transit of Ve­nus, June the 6th, 1761, made in Spital-Square; the longitude of which is 4' 11" west of the Royal Observatory at Green­wich, and the latitude 51° 31' 15" north

1761 ◽  
Vol 52 ◽  
pp. 182-183
Keyword(s):  
The Sun ◽  
Royal Observatory ◽  
The Mean ◽  
The Difference ◽  
Made In

Having measured the diameter of Venus, on the sun, three times, with the object-glass micrometer, the mean was found to be 58 seconds; and but 6/10 of a second, the difference of the extremes.

Effect of altitude on dietary-induced thermogenesis at rest and during light exercise in man

1978 ◽  
Vol 45 (3) ◽  
pp. 345-349 ◽  
Author(s):  
M. J. Stock ◽  
N. G. Norgan ◽  
A. Ferro-Luzzi ◽  
E. Evans
Keyword(s):  
Metabolic Rate ◽  
Specific Dynamic Action ◽  
Metabolic Rates ◽  
Postprandial Metabolism ◽  
Interindividual Differences ◽  
Liquid Meal ◽  
The Mean ◽  
Monte Rosa ◽  
Hypoxic Exercise ◽  
Made In

Measurements of metabolic rate and the thermic response (specific dynamic action) of a 400-kcal liquid meal were made in six subjects at rest and during light exercise. The tests were conducted before (LA1) and after (LA2) a 3-wk sojourn (HA1, HA2, HA3) at 3,650 m on the Monte Rosa. Fasting metabolic rate at rest increased inittally and then fell, as did fasting and fed exercising metabolic rates. The fall in metabolic rates, but not the initial increases, can be ascribed to the change in body weight. Resting thermic responses at altitude were only slightly lower than normal, although peak values were significantly depressed at HA2 (P less than 0.05). The mean exercising thermic response was also significantly lower at HA2 (P less than 0.05) but recovered in HA3 and LA2. In the time taken for thermic responses to decrease and recover there were interindividual differences that were best explained by the previous altitude experience of the subjects. The possibility of a cardiovascular shift during hypoxic exercise causing depression of postprandial metabolism is discussed.

scholarly journals The Pseudoscorpions of Illinois

1949 ◽  
Vol 24 (1-4) ◽  
pp. 413-500 ◽  
Author(s):  
C. Clayton Hoff
Keyword(s):  
United States ◽  
Natural Habitat ◽  
Habitat Preferences ◽  
The United States ◽  
Accurate Information ◽  
North Central ◽  
Taxonomic Importance ◽  
Central United States ◽  
Identification Of Species ◽  
Made In

Pseudoscorpions are minute animals only a few millimeters long, with the general appearance of diminutive scorpions except that they have no tails. They belong to the large phylum of joint-legged animals, the Arthropoda, and to the class Arachnida. which, in addition to the pseudoscorpions, embraces the spiders, mites, ticks, scorpions, and other related groups. Pseudoscorpions are seclusive in habit, occurring in soil cover and rotten logs, under bark, and in similar places out of doors: one species is found in houses. In their natural habitat, these little brown animals arc difficult to see. especially when they draw in their legs and "play possum." In this position they look like little specks of dirt. Probably because pseudoscorpions are inconspicuous, few collections of the group have been made in the past, and the fauna, at least of North America, and especially of the central and north-central United States, has remained scantily known. The object of this report is twofold, first to present illustrated keys and descriptions for the identification of species in this region, and, secondly, to summarize information regarding the distribution, biology, and habitat preferences of the species. As an aid in use of the keys, a section has been included on morphology, in which the structures now considered of major taxonomic importance are explained. Summarizing the distribution has been especially difficult because many identifications made prior to Chamberlin's work are probably incorrect and should be rechecked before they are cited. Because of this situation there is little accurate information to serve as a guide in foretelling what additional described species may be collected in Illinois. In order to make this report of wide application, the keys have been made to include all the genera known from the central and northeastern portions of the United States and adjacent portions of Canada.

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