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  • 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

Respiratory metabolism in Xantusia vigilis during temperature acclimation

Shaman, Toby Freda, 1928- January 1962 (has links)
No description available.
12

Climatic adaptation and cell sap concentration

Serviss, George H. January 1926 (has links)
No description available.
13

Mechanisms of heat acclimation and exercise performance

Lorenzo, Santiago, January 1900 (has links)
Thesis (Ph. D.)--University of Oregon, 2010. / Includes bibliographical references (leaves 213-245).
14

The Role of Cold Acclimatization on the Biogeography of the Mountain Chickadee (Parus Gambeli) and the Juniper Titmouse (Parus RIdgway)

Cooper, Sheldon J. 01 May 1997 (has links)
Biogeographic patterns of animals are shaped by biotic interactions, such as competition, and by abiotic factors, such as climate. Mountain Chickadees (Parus gambeli) and Juniper Titmice (Parus ridgway) are permanent residents of regions of western North America and are ecologically similar, but have different northern range limits. l measured several physiological variables, including basal metabolic rate (BMR), peak metabolic rate (PMR = maximal thermogenic capacity), metabolic response to varying environmental temperature (MRT), evaporative water loss (EWL), and daily energy expenditure (DEE) for summer-and winter-acclimatized Mountain Chickadees and Juniper Titmice to determine if seasonal and interspecific variation in cold tolerance and thermogenic ability shape the northern range distribution of these two species. In addition, I examined the ecological consequences of nocturnal hypothermia and cavity roosting in seasonally acclimatized Mountain Chickadees and Juniper Titmice. Winter birds tolerated colder test temperatures than summer birds for both species This improved cold tolerance was associated with a significant increase in PMR in winter chickadees (27.1 %) and titmice (114%) compared to summer. BMR was significantly higher in winter birds (16.0%) compared to summer birds for both species. BMR and PMR were significantly higher for chickadees compared to titmice in both summer and winter. Winter chickadees were able to withstand colder test temperatures than winter titmice. The Mountain Chickadee's lower critical temperature is lower than the Juniper Titmouse's in summer and in winter. The Mountain Chickadee's upper critical temperature is also lower than the Juniper Titmouse's and chickadees also had significantly higher evaporative water loss rates compared to titmice. Seasonal acclimatization in Mountain Chickadees involves insulatory as well as metabolic changes. For Juniper Titmice winter acclimatization appears to be primarily a metabolic process. The laboratory metabolism data for activity costs associated with DEE revealed that foraging energy requirements were not significantly higher than alert perching energy requirements. DEE was significantly higher (P<0.05) in winter-acclimatized chickadees and titmice compared to their summer counterparts. The marked increase in calculated DEE in winter birds compared to summer contrasts a pattern of increased DEE in the breeding season for several avian species. The data from this study indicate that the northern range limit of small birds can be limited by energetic and water balance demands.
15

A LATITUDINAL GRADIENT ANALYSIS OF ROCKY SHORE FISHES OF THE EASTERN PACIFIC

Lehner, Charles Edward January 1979 (has links)
No description available.
16

Acclimatization of micropropagated 'Silvan' blackberry

Tisdall, Laurence January 1990 (has links)
Tissue-cultured shoots and plantlets usually have leaves with non-functional, open stomata and little epicuticular and cuticular wax, resulting in excess evapotranspiration after transplantation. Various strategies were evaluated to decrease ex vitro acclimatization difficulties for 'Silvan' blackberry, including transplanting unrooted shoots, increasing the medium agar concentration from 6 to 9 or 12 g/l and diluting the basal medium. Increased medium agar concentrations and medium dilution did not improve survival or growth. Stomatal function resumed sooner in new leaves of plantlets than shoots. High relative humidity ($>$95%) and low light intensity (90 $ mu$mol s$ sp{-1}$ m$ sp{-2}$) negatively affected stomatal closure both on acclimatizing transplants and greenhouse-grown plants. Guard cells developed on leaves in vitro were physiologically active but had apparent anatomical abnormalities that inhibited closure. A rapid clearing and staining method was developed for examination of foliar morphology using intact in vitro blackberry (Rubus sp. 'Silvan') and strawberry (Fragaria x ananassa Duch. 'Totem') plantlets and sections of greenhouse-grown 'Silvan' and 'Totem' leaves. This method involved three steps: (1) removing the chlorophyll by autoclaving in 80% ethanol; (2) dissolution of the protoplasm using 5% NaOH at 80$ sp circ$C; (3) post-alkali treatment with 75% bleach (4.5% NaClO) at room temperature for tissue-cultured plantlets and at 55$ sp circ$C for greenhouse-grown leaves. Aqueous safranin (10 mg/l) was used for staining.
17

The role of plant water deficits on cold tolerance during cold acclimation of a cold tolerant (Poncirus trifoliata) and cold sensitive (Citrus unshiu) species

Dansereau, Kari Ann, January 2007 (has links) (PDF)
Thesis(M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references.
18

Thermal acclimation of photosynthesis and respiration in Pinus radiata and Populus deltoides to changing environmental conditions : a thesis submitted in fulfilment of the requirement for the degree of Doctor of Philosophy in Plant Physiology at the University of Canterbury /

Ow, Lai Fern Genevieve. January 2008 (has links)
Thesis (Ph. D.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (p. 172-194). Also available via the World Wide Web.
19

Transformation adaptation: developing a framework for donor organisation support of climate change adaptation in resource poor communities

Dada, Rehana January 2015 (has links)
Poor communities already face severe challenges in meeting their basic needs, whether because of poor income opportunities, inadequate service delivery, or degraded ecosystems that can no longer support the needs of people. Non profit organisations who provide support for development are also challenged by financial restrictions and social and political structures that prevent or limit project development. Climate change is understood to have the most severe impact on the most vulnerable communities and sectors of communities by reducing the availability and accessibility of basic resources such as water, food and energy, impacting severely on human health and wellbeing, and further reducing the capacity of ecosystems to support livelihoods. This will add a layer of significant new complications to the ability of poor communities to maintain or improve standards of living, and further challenge non profit organisations that support such communitiesAnticipatory adaptation to climate change can reduce some of the impacts of climate change, and also address some key development stresses. This thesis aims to provide a framework that is relevant for supporting adaptation to climate change within the context of resource poor communities in a developing country. Non profit organisations and donor agencies could support success and autonomy in adaptation processes by making provision for locally defined understanding of adaptation, and locally determined processes and programmes. This can be taken further into implementation of programming that addresses local short term development priorities alongside, or as part of long term adaptation work. The research followed a number of steps involving a multitude of techniques including literature review, interviews, a survey, consultation with an expert group, further consultation with stakeholders, and a final electronic review. Its outcome is a strategy that can be used to support climate change adaptation in resource poor communities. A definition for adaptation is proposed as an interpretation of adaptation that is relevant in this context. The intended end goal of adaptation as defined in this research is a better form of development that : supports a harmonious and respectful relationship between humans and their natural resource base; averts further destructive global change or at the very least prevents it from becoming unmanageable; and manages the impacts of past and ongoing destructive change so that there is lowest possible loss of natural, human, or cultural resources. The term transformative adaptation emerged from the research processes to describe adaptation to climate change that concurrently addresses development challenges, is grounded in community development aspirations, integrates programming work across multiple thematic areas and approaches, and addresses the causes of climate change within adaptation interventions. The following broad guidelines are used to inform programming within the framework of transformative adaptation : Human communities are faced with an enormous challenge resulting from global change and sociopolitical injustices; Well planned anticipatory adaptation can limit exposure and vulnerability to at least some of the projected impacts of climate change; Adaptation to climate change incorporates a reduction of vulnerability to underlying development stresses, alongside a reduction of vulnerability to specific climate change stresses; Existing development work forms the foundation for adaptation interventions, acknowledging the interdependence of social, natural and economic systems and the need to maintain their health; Adaptation decision making is community based, and acknowledges that resource poor communities are best placed to establish their own development needs, drive implementation of interventions in own spaces, and identify own limits to adaptation; Adaptation work incorporates mitigation objectives so that the causes of climate change are addressed as part of the strategy for coping with climate change; Adaptation programming acknowledges the strong interlinkages between, and integrates work across, the thematic areas of water security, food sovereignty, energy security, land security, human wellbeing and livelihood diversity; Adaptation uses a broad set of approaches that spans research, knowledge sharing, advocacy, and investment in technology and infrastructure; There is flexibility in project design and implementation to allow room for experimentation with new concepts, and also to change design as knowledge, understanding, and geophysical, biophysical and sociopolitical conditions change.
20

Microclimate mosaic and its influence on behaviour of free-living African forest elephants (Loxodonta africana cyclotis)

Kuwong, Michael Viyof 22 August 2014 (has links)
African elephants are known to survive in habitats with ambient temperatures from below 0°C to about 50°C, implying that they may be exposed to great thermal challenges, especially in hot regions of Africa, where they are common. Thermoregulatory behaviour of the African forest elephant in its natural habitat and the microclimates that it utilizes have not previously been investigated. To understand how such an enormous animal behaves in the hot, humid natural forest environment, I investigated microclimates at forest-savannah interfaces (bais) in Lobeke National Park in Cameroon, observed forest elephants’ likely thermoregulatory behaviour and correlated the behaviours with environmental microclimatic variables. Portable weather stations equipped with data loggers were deployed at five study sites to record microclimatic variables for three days per site. I used the fixed point sampling method to observe and record behaviours of forest elephants, during the hot, dry season. Black globe temperature reached an average of about 33ºC during the day in the bais and decreased to a mean of about 20ºC in the night. The day globe temperature often exceeded the body temperature of the elephants, but the vapour pressure of air was lower than that on the elephant’s skin. Therefore, at 100% humidity and estimated skin temperature of 35ºC, I assume elephants of this study lost heat by evaporation, both under the forest canopy and in the open bais. Wind speed in the bais was higher than that under the forest canopy, possibly facilitating convective heat loss from the elephants, particularly at night. Ear-flapping rate of the elephants correlated linearly and positively with dry-bulb and globe temperatures. Shade-seeking and dust-bathing only showed weak positive associations both with dry-bulb globe and temperatures. Between 06:00-24:00, elephants that were observed spent a mean of 40% of their time walking, 55% foraging, 7% shade-seeking, 45% ear-flapping, 4% dust-bathing and 9% of time performing water-related activities. The higher number of elephants in the bais at night as opposed to the numbers in the bais during the day, as revealed by the findings of this study, suggests that the forest elephant may have a more favourable mode of dumping its excess body heat in the open bais than under the forest canopy at night. All the bais and their vicinity that were investigated in this study were heavily trampled with elephant spoors, because many elephants frequently congregated in the area due the presence of nutritious herbaceous plants, mineral salts and variations in microclimates in the bai-savannah interfaces. The differences in microclimates in the bais and their vicinity may play a major role in influencing the forest elephant’s thermoregulatory behaviour. To the best of my knowledge, my study suggests for the first time that the forest elephant may use microclimates at the bai interface for thermoregulatory needs. However, my study is limited because it was executed for a short duration and over the hot dry season, and factors that may affect elephants such as physiology, the availability and quality of forage and predation risk were not included in this investigation. All these factors may have affected the accuracy of my findings. For these reasons the inferences made in this study on elephant microclimate selection would need further investigation before concrete conclusions are drawn. Expensive research cost, human safety, fear of human presence and hence alteration of elephant behaviour and the obscure nature of the equatorial forest have been recurrent issues hindering the investigation of behaviour of free-living African forest elephants. I suggest that it would be worthwhile investigating the forest elephant’s behaviour further by applying GPS/satellite telemetry, real time bio-logging and camera trap techniques, which offer a practical means to carry out an extensive study in the evergreen hot humid equatorial forest of the Congo Basin.

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