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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.
1

The energetics of lactation in Antarctic fur seals (Artocephalus gazella)

Arnould, John Peter Yves January 1995 (has links)
The use of hydrogen isotope dilution to measure total body water (TBW) and body composition in fur seals was validated by comparison with whole-carcass chemical analysis. Adult females had proportionately lower TBW and higher gross energy contents than pups. Pups had higher TBW to lean body mass ratios than adults indicating they had not yet reached chemical maturity. At all ages, there were significant differences in body composition between pup sexes. Whereas female pups were generally lighter than males, for any given mass they had significantly higher body lipid reserves. The amount of milk energy consumed by pups during the 1-2 day maternal attendance periods ranged from 49 - 68 MJ and increased steadily with age before decreasing significantly in the last 30 - 40 days before weaning. There were no significant differences in milk consumption between male or female pups. The amount consumed during these attendance periods was positively related to the duration of maternal absence such that daily energy consumption (on average 8.3 MJ) was independent of maternal foraging trip duration. Because pups must fast during the long maternal absences, the majority of the resources transferred to the pup are used for maintenance instead of growth. Analysis of the relationship between foraging behaviour and energy expenditure indicated that females undertaking short foraging trips had higher dive rates but lower metabolic rates than females making longer trips. However, females making longer trips gained more mass such that the energetic efficiency with which they gained mass was independent of foraging trip duration or diving behaviour. The total energetic cost of milk production and metabolism during the lactation period are estimated at 940 MJ and 2161 MJ, respectively. The total food energy consumed by individual adult female Antarctic fur seals at South Georgia during the lactation period is estimated at 3710 MJ.
2

Mother-pup recognition behaviour, pup vocal signatures and allosuckling in the New Zealand fur seal, Arctocephalus forsteri

Dowell, Sacha January 2005 (has links)
A recognition system is required between pinniped mothers and pups. For otariids this is especially important since females frequently leave their pups for foraging and must reunite on return. Pups must deal with these fasting periods during maternal absence and consequently may attempt to obtain allomaternal care from unrelated females. This research on the New Zealand fur seal (Arctocephalus forsteri) at Ohau Point, Kaikoura, New Zealand, quantified mother-pup recognition behaviour during reunions, individuality of pup calls used by mothers to recognise their pup, and the occurrence of allosuckling as a possible recognition error by females and as a strategy employed by pups to gain allomaternal care during their mothers' absence. A combination of behavioural observations, morphometry, VHF radio telemetry, acoustics and DNA genotyping were employed to study these topics. Postpartum interaction behaviours between mothers and pups appeared to facilitate development of an efficient mother-pup recognition system, involving mainly vocal and olfactory cues that were utilised during reunions. Greater selective pressure on pups to reunite resulted in an asymmetry of searching behaviour between females and pups during reunions. The vocalisations of pups were stereotypic, especially those features of the fundamental frequency and frequency of the lowest harmonic, which are likely to facilitate recognition of a pup by their mother. Pups attempted to steal milk from unrelated females more often during maternal absence and appeared to modify the intra-individual variation pattern of a feature of their vocal signatures over this period, which may assist attempts at allosuckling under nutritional stress. Fostering was demonstrated to occur despite costs to filial pups and possible costs to female reproductive success and may be attributed to development of erroneous recognition between females and non filial pups, or kin selection. This study provides a valuable contribution to the knowledge of recognition systems between pinniped mothers and pups, of alternative pup strategies under nutritional stress and of the rare occurrence of fostering in otariid pinnipeds.
3

New Zealand fur seals in the Kaikoura region: colony dynamics, maternal investment and health

Boren, Laura Joy January 2005 (has links)
Colony dynamics, maternal investment, and indicators of health were investigated for the New Zealand fur seal (Arctocephalus forsteri) over four austral summers, 2001- 2005. Effort was focused at the Ohau Point seal colony, north of Kaikoura. Two colonies at Banks Peninsula were included for comparisons of colony growth and pup condition. A range of other colonies were also included for making comparisons about colony dynamics and health indices. Colony dynamics were investigated through mark-recapture estimates of pup production and daily census of all individuals at the Ohau Point colony. Maternal attendance patterns were observed through behavioural observations of known females (n = 120), the use of VHF radio transmitters (n = 33), and female mass and body condition estimates (n = 51). Maternal investment was also investigated through longitudinal sampling of pup mass and growth rates. Parameters used to indicate colony health were: body condition, growth, presence of parasites, and the levels and common causes of mortality. The influence of parasites on pup growth was tested using treatment of selected pups with Ivermectin anti-helmentic medication, and mortality in the region was investigated through reports of dead individuals, and post mortems of those found fresh. The Ohau Point colony is in an exponential state of growth, and pup mass and condition was higher and responded to changes in environmental variables differently than at the Banks Peninsula colonies. Lactation lengths were consistently longer at Ohau Point than is typically reported for the species (323-355 days vs. 285 days). Maternal investment strategies were indicative of a close, reliable food source, and showed flexibility between years through extension of foraging trip durations and the increased use of overnight foraging trips. Individual strategies did not significantly influence pup growth. However, increased maternal condition and the ability to respond to inter-annual changes in resource availability resulted in accelerated pup growth even during an El Niño event. The incidence of pups with intestinal parasites was low at Ohau Point, and the average mass of treated and non-treated pups did not differ. Pup mortality in the region was low (3% to 50 days old), however, mortality of older pups was greatly influenced by the proximity of humans, with 2/3 of pup mortality observed between the age of 50 days and weaning being caused by car collisions. The results suggest that population dynamics and maternal investment in the region are greatly influenced by local variables, notably the presence of an accessible food source within close proximity to the colony. Various indicators of health reflect a growing colony in good condition, and the presence of a reliable food source may influence the maximum density and carrying capacity the colony is able to sustain. However, some concerns are raised about the influence of human interactions in the region, and how this may affect mortality and colony dynamics in the future. Extra fencing along the Ohau Point colony is recommended to provide added protection from the road. Continued monitoring of mortality and health indices in the region is also recommended for comparison with other colonies as Ohau Point reaches carrying capacity and density-dependent pressures increase.
4

Prototyping a Well-Driver PUP (Purdue Utility Project) to Install Low-Cost Driven Water Wells

Zackariah J Horn (6632300) 11 June 2019 (has links)
<p>People living in developing countries or undeveloped regions often do not have proper access to quantities of safe, clean water to fulfill their daily needs. Certain members of the families, often women and children, walk miles every day to collect surface waters that are frequently contaminated. To improve water availability and quality, a sustainable mechanical solution to more safely access groundwater has been developed.</p> <p> </p> <p>A well-driving attachment for a PUP (Purdue Utility Project) vehicle provides a low-cost means for installing driven type wells in areas of high to medium water table heights. PUP vehicles have a niche in developing countries, as they offer impressive value and utility in comparison to other powered machines. The vehicles are built and sourced using locally available materials with basic tooling. A hydraulic post driver has been attached to the rear of a PUP frame to serve as an impact mechanism, driving a well point and a series of inter-connecting pipes to serve as a permanent casing for the well. </p> <p> </p> <p>Water wells were tested at four different test sites around central Indiana, with the deepest well reaching 23 feet. This suggests that the Well-Driver PUP can install driven water wells in areas of medium to high water tables and may be suitable for a development setting. Water wells can be installed on a communal basis, thus providing an increased level of hygiene and standards of living. Low-cost driven water wells will provide a drinking water supply that is better protected than a hand-dug well and will reduce the likelihood of disease caused by waterborne pathogens. Development of the Well-Driver PUP prototype and its applications will be discussed.</p>
5

Drug/inflammation nutrient transport interaction in the lactating mother-neonate dyad

Ling, Binbing 05 February 2010
This dissertation research involved investigations into possible drug-nutrient or disease-nutrient transport interactions in the nursing mother-neonate dyad. The overall hypothesis was that cefepime would inhibit L-carnitine transport at the lactating mammary gland and in developing neonates. Additionally, inflammation would alter energy substrate transporter expression in mammary tissue.<p> The first objective was to investigate the potential for drug-nutrient transport interactions at the lactating mammary gland. A continuous cefepime infusion to lactating rats reduced L-carnitine transfer into milk at early but not mid lactation. In conjunction with higher milk L-carnitine and cefepime concentrations and higher expression levels of Octn2, the data suggests cefepime competitively inhibited Octn2-mediated L-carnitine transport into milk.<p> The second objective was to assess the influence of lactation stage on milk-to-serum ratios (M/S) for an actively transported drug, cefepime, and its impact on the calculation of neonatal exposure indices. Higher cefepime M/S on day 4 lactation versus day 10 coupled with lower systemic clearance values for cefepime in postnatal day 4 versus day 10 pups resulted in >7-fold higher exposure index values at postnatal day 4. These data confirm the need to determine M/S at different lactation stages for actively transported drugs to avoid over- or underestimation of neonatal exposure risk.<p> The third objective was to examine a drug-nutrient transporter interaction in neonates. Cefepime administered twice daily according to different dosing schedules (postnatal days 1-4, 1-8, 8-11, 8-20 and 1-20) caused significant alterations in the ontogenesis of several mechanisms involved in the L-carnitine homeostasis. These alterations likely represented adaptive responses to cefepime inhibition of L-carnitine transport. Furthermore, these changes seemed to depend on duration and timing of exposure relative to postnatal maturation.<p> The fourth objective was to examine the effects of inflammatory stimuli on energy substrate transporter expression in mammary tissue. Inflammatory stimuli altered expression of glucose, fatty acid and L-carnitine transporters in mammary tissue <i>in vitro</i> and <i>in vivo</i>.<p> Collectively, this research provided experimental evidence for significant disease- or drug-nutrient transport interactions in the nursing mother-neonate dyad. Further research may identify a need for dietary modification during pharmacological management of disease in the nursing mother-neonate dyad.
6

Mother-pup interaction and the impact of anthropogenic disturbance in wild harbour seals (Phoca vitulina)

Groothedde, Julia January 2011 (has links)
This study investigated the abundance of harbour seals (Phoca vitulina) on inter-tidal sandbanks, mother-pup interactions as well as the impact of anthropogenic disturbance during breeding season. The abundance was a composite picture of harbour seals of different age and sex, and increased gradually towards peaks in June. Although the sandbank water inlet was the longest time emerged, mother-pup pairs and other seals hauled out more abundant on the other sandbanks, probably due to space availability, differences in sandbank structure and distance to human activity. Mothers and their offspring were found to be mostly inactive during haul out. Mothers initiated significantly more frequently interactions i.e. hauling out, entering water and suckling. Seals hauled out at sandbanks close to the dyke were most frequently disturbed by pedestrians. Important regarding the impact on the seals seemed to be the group size of pedestrians and the distance to the seals (on dyke or seaside of it), i.e. pedestrians seaside disturbed more seals. This applies also to the disturbance by marine activity, e.g. distance of seals to the engine boat. Jet fighters were shown to affect the highest mean number of seals per event. After anthropogenic disturbances separations of mother and offspring were not recorded, e.g. due to seals being in the water; however, the steep edges as result of the culvert at water inlet lead to a few separations. The most frequent behavioural response towards anthropogenic disturbance was commotion with a probably lower level of energy costs during the energy consuming lactation period.
7

Drug/inflammation nutrient transport interaction in the lactating mother-neonate dyad

Ling, Binbing 05 February 2010 (has links)
This dissertation research involved investigations into possible drug-nutrient or disease-nutrient transport interactions in the nursing mother-neonate dyad. The overall hypothesis was that cefepime would inhibit L-carnitine transport at the lactating mammary gland and in developing neonates. Additionally, inflammation would alter energy substrate transporter expression in mammary tissue.<p> The first objective was to investigate the potential for drug-nutrient transport interactions at the lactating mammary gland. A continuous cefepime infusion to lactating rats reduced L-carnitine transfer into milk at early but not mid lactation. In conjunction with higher milk L-carnitine and cefepime concentrations and higher expression levels of Octn2, the data suggests cefepime competitively inhibited Octn2-mediated L-carnitine transport into milk.<p> The second objective was to assess the influence of lactation stage on milk-to-serum ratios (M/S) for an actively transported drug, cefepime, and its impact on the calculation of neonatal exposure indices. Higher cefepime M/S on day 4 lactation versus day 10 coupled with lower systemic clearance values for cefepime in postnatal day 4 versus day 10 pups resulted in >7-fold higher exposure index values at postnatal day 4. These data confirm the need to determine M/S at different lactation stages for actively transported drugs to avoid over- or underestimation of neonatal exposure risk.<p> The third objective was to examine a drug-nutrient transporter interaction in neonates. Cefepime administered twice daily according to different dosing schedules (postnatal days 1-4, 1-8, 8-11, 8-20 and 1-20) caused significant alterations in the ontogenesis of several mechanisms involved in the L-carnitine homeostasis. These alterations likely represented adaptive responses to cefepime inhibition of L-carnitine transport. Furthermore, these changes seemed to depend on duration and timing of exposure relative to postnatal maturation.<p> The fourth objective was to examine the effects of inflammatory stimuli on energy substrate transporter expression in mammary tissue. Inflammatory stimuli altered expression of glucose, fatty acid and L-carnitine transporters in mammary tissue <i>in vitro</i> and <i>in vivo</i>.<p> Collectively, this research provided experimental evidence for significant disease- or drug-nutrient transport interactions in the nursing mother-neonate dyad. Further research may identify a need for dietary modification during pharmacological management of disease in the nursing mother-neonate dyad.
8

Early Migratory Behavior of Northern Fur Seal (Callorhinus ursinus) Pups from Bering Island, Russia

Lee, Olivia Astillero 2011 May 1900 (has links)
I examined the population trends of northern fur seals (Callorhinus ursinus) using an age-specific metapopulation model that allowed migration between rookeries. Mortality and birth rates were modified to simulate future population trends. I also examined the early migratory behavior and habitat associations of pups from Bering Island (BI), Russia. I instrumented 35 pups with Mk10-AL satellite tags and stomach temperature telemeters which provided diving, foraging and location data. I hypothesized that some aspects of pup behavior from the stable BI population differed from the behavior of pups from the unstable Pribilof Islands (PI). The population model revealed that emigration did not contribute significantly to the current PI population decline. However, large source populations contributed significantly to population growth in newly colonized rookeries. A stabilization of the PI population was predicted with a 10 to 20 percent reduction in both juvenile and adult female mortality rates. The diving behavior of pups showed a general progression towards longer and deeper dives as pups aged, particularly between 1600 – 0400 (local time), that was similar to PI pup behavior. However, unlike pups from the PI, I found three main diving strategies among BI pups: 1) shallow daytime divers (mean depth = 3.56 m), 2) deep daytime divers (mean depth = 6.36 m) and 3) mixed divers (mean depth = 4.81 m). The foraging behavior of pups showed that most successful ingestion events occurred between 1600 – 0400, with successful ingestion events lasting 25.36 plus/minus 27.37 min. There was no significant difference among the three strategies in the depth of successful foraging dives. I also examined the foraging search strategies in adult females and pups. Both pups and adults conducted Levy walks, although pups foraged in smaller patches (1 km scales). Using a logistic model to determine habitat associations, I found that pup locations were positively correlated with increasing chlorophyll a concentrations, distances from shore, and sea surface temperatures, and were negatively correlated with depth. There was no significant relationship between all pup locations and the regions (peripheries or centers) or types (cyclonic or anti-cyclonic) of eddies, but ingestion event locations were related to mesoscale eddy peripheries.
9

Mother-pup recognition behaviour, pup vocal signatures and allosuckling in the New Zealand fur seal, Arctocephalus forsteri

Dowell, Sacha January 2005 (has links)
A recognition system is required between pinniped mothers and pups. For otariids this is especially important since females frequently leave their pups for foraging and must reunite on return. Pups must deal with these fasting periods during maternal absence and consequently may attempt to obtain allomaternal care from unrelated females. This research on the New Zealand fur seal (Arctocephalus forsteri) at Ohau Point, Kaikoura, New Zealand, quantified mother-pup recognition behaviour during reunions, individuality of pup calls used by mothers to recognise their pup, and the occurrence of allosuckling as a possible recognition error by females and as a strategy employed by pups to gain allomaternal care during their mothers' absence. A combination of behavioural observations, morphometry, VHF radio telemetry, acoustics and DNA genotyping were employed to study these topics. Postpartum interaction behaviours between mothers and pups appeared to facilitate development of an efficient mother-pup recognition system, involving mainly vocal and olfactory cues that were utilised during reunions. Greater selective pressure on pups to reunite resulted in an asymmetry of searching behaviour between females and pups during reunions. The vocalisations of pups were stereotypic, especially those features of the fundamental frequency and frequency of the lowest harmonic, which are likely to facilitate recognition of a pup by their mother. Pups attempted to steal milk from unrelated females more often during maternal absence and appeared to modify the intra-individual variation pattern of a feature of their vocal signatures over this period, which may assist attempts at allosuckling under nutritional stress. Fostering was demonstrated to occur despite costs to filial pups and possible costs to female reproductive success and may be attributed to development of erroneous recognition between females and non filial pups, or kin selection. This study provides a valuable contribution to the knowledge of recognition systems between pinniped mothers and pups, of alternative pup strategies under nutritional stress and of the rare occurrence of fostering in otariid pinnipeds.
10

New Zealand fur seals in the Kaikoura region: colony dynamics, maternal investment and health

Boren, Laura Joy January 2005 (has links)
Colony dynamics, maternal investment, and indicators of health were investigated for the New Zealand fur seal (Arctocephalus forsteri) over four austral summers, 2001- 2005. Effort was focused at the Ohau Point seal colony, north of Kaikoura. Two colonies at Banks Peninsula were included for comparisons of colony growth and pup condition. A range of other colonies were also included for making comparisons about colony dynamics and health indices. Colony dynamics were investigated through mark-recapture estimates of pup production and daily census of all individuals at the Ohau Point colony. Maternal attendance patterns were observed through behavioural observations of known females (n = 120), the use of VHF radio transmitters (n = 33), and female mass and body condition estimates (n = 51). Maternal investment was also investigated through longitudinal sampling of pup mass and growth rates. Parameters used to indicate colony health were: body condition, growth, presence of parasites, and the levels and common causes of mortality. The influence of parasites on pup growth was tested using treatment of selected pups with Ivermectin anti-helmentic medication, and mortality in the region was investigated through reports of dead individuals, and post mortems of those found fresh. The Ohau Point colony is in an exponential state of growth, and pup mass and condition was higher and responded to changes in environmental variables differently than at the Banks Peninsula colonies. Lactation lengths were consistently longer at Ohau Point than is typically reported for the species (323-355 days vs. 285 days). Maternal investment strategies were indicative of a close, reliable food source, and showed flexibility between years through extension of foraging trip durations and the increased use of overnight foraging trips. Individual strategies did not significantly influence pup growth. However, increased maternal condition and the ability to respond to inter-annual changes in resource availability resulted in accelerated pup growth even during an El Niño event. The incidence of pups with intestinal parasites was low at Ohau Point, and the average mass of treated and non-treated pups did not differ. Pup mortality in the region was low (3% to 50 days old), however, mortality of older pups was greatly influenced by the proximity of humans, with 2/3 of pup mortality observed between the age of 50 days and weaning being caused by car collisions. The results suggest that population dynamics and maternal investment in the region are greatly influenced by local variables, notably the presence of an accessible food source within close proximity to the colony. Various indicators of health reflect a growing colony in good condition, and the presence of a reliable food source may influence the maximum density and carrying capacity the colony is able to sustain. However, some concerns are raised about the influence of human interactions in the region, and how this may affect mortality and colony dynamics in the future. Extra fencing along the Ohau Point colony is recommended to provide added protection from the road. Continued monitoring of mortality and health indices in the region is also recommended for comparison with other colonies as Ohau Point reaches carrying capacity and density-dependent pressures increase.

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