• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 36
  • 18
  • 15
  • 8
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 97
  • 97
  • 97
  • 27
  • 19
  • 19
  • 12
  • 12
  • 12
  • 12
  • 11
  • 11
  • 11
  • 8
  • 8
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Analog computer study of a biological temperature regulator : cutaneous circulation

Moore, Alan Arthur January 2011 (has links)
Digitized by Kansas State University Libraries
12

The design and analysis of two dry ice personal cooling jackets

Chanda, Ashok. January 1979 (has links)
Call number: LD2668 .T4 1979 C52 / Master of Science
13

Endothermy and thermoregulation in solitary bees

Stone, Graham N. January 1990 (has links)
This thesis examines the roles of endothermy and body size in the thermal biology of solitary bees (Hymenoptera: Apoidea) within the species Anthophora plumipes (Anthophoridae) Amegilla sapiens (Anthophoridae) and Creightonellafrontalis (Megachilidae), within the genus Anthophora, and over the Apoidea as a whole. The effects of body size, climate and sexual interactions on the biology of Anthophora plumipes were investigated in Oxford between 1987 and 1989. Both ambient temperature and body size had a significant effect on females' ability to forage, what time they initiated foraging in the morning, and the type and mass of provisions collected. The behaviour of males was also strongly dependent on ambient temperature, which affected not only when they emerged from their nest tunnels, but also how long they spent basking, when and where they fed, and whether they showed courtship behaviour. The activity patterns and behaviour of male and female A. plumipes over time were shown to correlate with a complex array of factors. Activity patterns of females depended on the quality of floral resources available at foraging sites, body mass, ambient temperature, the position of the female in her nest-provisioning cycle, and levels of male interference at foraging sites. Male behaviour not only depended on body size and ambient temperature, but also on which other bees (particularly male and female conspecifics) were encountered while patrolling food sources and at the nest site. Endothermy in bees is much more widespread than previously thought, and warm-up before flight was present to some degree in all the species examined. Levels of thermoregulation achieved, however, varied considerably between species. Warm-up rates in bees, and thoracic temperatures in free and tethered flight, are shown to depend on ambient temperature and body mass within a species (for temperate and tropical examples), across members of the genus Anthophora and across the Apoidea as a whole. The persistence of these relationships over a range of comparative levels suggests that they are of fundamental importance. The form of these relationships differs between families in the Apoidea, and significant patterns only emerge when a comparative technique controlling for phylogeny is applied. Furthermore, body temperatures may also depend, in at least some cases, on sex and there may be differences within a group of related species between provisioning and parasitic forms. The interaction of all these factors is complex, and the predictive value of a variable such as body mass does not always emerge unless sophisticated techniques are used to control for other variables. The errors associated with two common methods in the measurement of insect body temperatures have often been loosely discussed but rarely quantified. This thesis examines (a) the magnitude and possible effects of errors in 'grab-and-stab' measurement of body temperature, and (b) the errors in measurement of body temperature using fixed sensors linked by thermally conducting leads to measuring devices. In neither case do the demonstrated errors preclude use of the technique, but care with interpretation is required. In both cases, measurement of thoracic temperature in small bees involves the largest errors, and this is the most serious obstacle to comparisons of endothermic and thermoregulatory abilities over the full range of body sizes found in the Apoidea.
14

Biologging as a method to remotely detect orientation to solar radiation in black and blue wildebeest

Botha, Arista 17 April 2015 (has links)
A dissertation submitted to the University of the Witwatersrand in fulfilment of the requirements for the degree of Master of Science in Medicine Johannesburg 2014 / Animals can shift their orientation to solar radiation to adjust the amount of body surface area that is exposed to solar radiation, thereby manipulating the amount of radiant heat they absorb from their environment. This behaviour is especially important in animals that need to graze out in the open during the day, such as wild ungulates. All previous studies of orientation to solar radiation in animals have relied on visual observations. The problem with visual observations is that animal behaviour, including animal orientation, can be affected by human presence. Therefore I set out to develop a remote technique to detect and quantify orientation to solar radiation in wildebeest to eliminate the need of a human observer. I hypothesised that if an animal was orientated perpendicular to solar radiation, the side facing the sun would be hotter than the opposite side. In contrast, if the animal was orientated parallel to solar radiation I hypothesised that both sides will have a similar temperature. To test my hypothesis, temperature-sensitive data loggers were implanted subcutaneously into free-ranging black (Connochaetes gnou) and blue wildebeest (Connochaetes taurinus) from Mokala National Park and their orientation to solar radiation was determined visually. I found that when wildebeest were orientated perpendicular to solar radiation, there was a greater difference between the left and right subcutaneous temperature than when wildebeest were orientated parallel to solar radiation (t7=2.5, p=0.04). However, using subcutaneous temperature difference on its own to predict orientation to solar radiation could not account for how the previous orientation to solar radiation of wildebeest affected subcutaneous temperature patterns. Therefore, I designed a prediction model incorporating both subcutaneous temperature difference and rate of change in subcutaneous temperature difference to determine orientation to solar radiation. The prediction model was accurate more often than expected by chance (60 %), but there were many factors other than solar radiation that influenced subcutaneous temperature, which reduced the accuracy of the remote technique. Further research is necessary to improve the remote technique before it can be successfully used to study orientation to solar radiation. However, my study shows, for the first time, the potential of using subcutaneous temperatures to remotely detect orientation to solar radiation in ungulates. A remote technique to study orientation to solar radiation will be a great advantage for future studies on thermoregulatory behaviour. Because behavioural responses are likely to be an animal’s first defence against increased heat loads resulting from climate change, studying behavioural thermoregulation could provide important information for conservation and management decisions.
15

Thermal Effects on the Performance of Schoolchildren

Schiefer, RE January 1991 (has links)
A Thesis submitted to the Faculty of Medicine,University of the Witwatersrand,Johannesburg, for the Degree of Doctor of Philosophy in Medicine / The effects of different thermal conditions on the performance and physiology of schoolchildren were determined. Children performed simulated school tasks in controlled indoor environments. The quality and speed of their performance on the task was recorded,as were weight, height, oral temperature, finger skin temperature and unprepared reaction time. The influence of personal parameters such as socioeconomic status was also investigated / IT2017
16

The relationship between essential fatty acids and fever

Benedict-Kenedi, Eva January 1990 (has links)
A thesis submitted to the Faculty of Medicine, University o-f the Witwatersrand, Johannesburg, ■for the degree o-f Master o-f Science. Johannesburg, 1990. / In this thesis the role of essential fatty acids (EFAs) in thermoregulation and the polyunsaturates (PUFA) in the genesis of fever is investigated. Although recognised, that metabolites of arachidonic acid are involved in the biochemical sequences leading to fever, it is also acknowledged that fever response depends on lipid mobilisation. However, the exact biochemical mechanisms involved in this event remain unknown to date. In order to investigate a relation between serum lipids and fever, rabbits were subjected to dietary manipulation (deficient, or excessive EFA diet) and their hyperthermic responses to intravenous injections of (a) human leucocyte pyrogen (HLP); (b) endotoxin (Salmonella Thyphosa); and (c) cerebroventricular injections of prostaglandin E2» were compared with rabbits fed on a normal diet / IT2018
17

The design and evaluation of a dry-ice jumpsuit

Tang, Jack Wen-Yen January 2011 (has links)
Digitized by Kansas Correctional Industries
18

Coping with the cold: heterothermic mammals provide a new paradigm for surfactant composition and function / Carol Ormond.

Ormond, Carol Jane January 2003 (has links)
"November, 2003" / Includes bibliographical references (leaves 240-264) / xix, 264 : ill. (some col.), plates ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, School of Earth and Environmental Sciences, Discipline of Environmental Biology, 2004
19

Behavioral thermoregulation in the javelina (Tayassu tajacu)

Phelps, John Stanley, 1941- January 1971 (has links)
No description available.
20

The effect of thermal stress and caffeine on water balance and excretion of nitrogen constituents

Taylor, Richard Emery, 1927- January 1964 (has links)
No description available.

Page generated in 0.096 seconds