Дисертації з теми "Seasonal physiology"
Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Seasonal physiology.
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Seasonal physiology".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
Spacht, Drew Evan. "Seasonal, habitat, and stress-related responses of insects in cold environments." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1588946793797684.
2
Shangguan, Bumin. "A seasonal study of male reproduction and sperm physiology of three coldwater flatfish." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0020/NQ54852.pdf.
3
Ingvarsdottir, A. "Seasonal changes in physiology and chemical composition of Calanus finmarchicus late copepodite stages." Thesis, University of Aberdeen, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287608.
Анотація:
Late copepodite and adult stages of the copepod Calanus finmarchicus were collected north of Shetland, in the Faroe-Shetland Channel and West of Ireland on seven occasions from October 1993 to March 1996. In winter the population was found in highest concentrations at depths greater than 500 meters around the 0°C isotherm and consisted mainly of copepodite stage CV in a state of diapause. The project investigated seasonal fluctuations in dry weight, carbon, nitrogen, protein and RNA content and respiration rates. The study indicate that moulting, ovary development and ascent from overwintering depth to the surface waters in the spring is largely dependent on reserves stored from the previous summer. Oxygen consumption rates were very low at in situ temperatures in winter (7 - 30 μmol O2 gC-1 h-1 for stage CV, 29 - 148 μmol O2 gC-1 h-1 for stage CV, 332 μmol O2 gC-1 h-1 for females). Overwintering animals showed significant response to changes in temperature. The animals regulated their oxygen consumption with declining partial pressure of oxygen but oxygen consumption decreased when oxygen tension dropped below 80 Torr for stage CV and 100 Torr for females. Oxygen consumption tended to decrease with increasing body weight but he correlation was poor, possibly owing to the variable amount of stored fat. In March respiration rates of fed stage CV were consistently higher than for non-feeding specimens at all temperatures. Temperature constituted a major factor in the change in respiration rates while feeding increased the oxygen consumption only slightly. A model was constructed to estimate survival of overwintering animals with carbon content equivalent to that expected of animals in October. In order to survive during winter and have enough energy for moulting and ascent these animals have to live at temperatures close to 0°C and be in a diapause state.
4
McStay, Elsbeth. "Photoperiod regulation of molecular clocks and seasonal physiology in the Atlantic salmon (Salmo salar)." Thesis, University of Stirling, 2012. http://hdl.handle.net/1893/11012.
Анотація:
Recent years have seen considerable advances in the study of biological rhythms and the underlying molecular mechanisms that drive the daily and seasonal physiology of vertebrates. Amongst teleosts the majority of work in this field has focused on the model species the zebrafish to characterise clock genes and the molecular feedback loop that underpins circadian rhythms and physiology. Daily profiles of clock gene expression in a wide variety of tissues and cell types are now relatively well described. However the zebrafish is a tropical species that does not display distinct seasonality and therefore may not be the species of choice to investigate the entrainment of circannual physiology. In contrast, Atlantic salmon is a highly seasonal teleost that displays considerable temporal organisation of most physiological processes. In salmonids photoperiod is widely known to synchronise physiology to the environmental conditions and as such photoperiod manipulation is routinely used by the salmon industry throughout the production cycle to control and manipulate spawning, smoltification and puberty. Previous studies in salmonid species have already identified a set of clock genes that are linked to these seasonal physiological processes. However, to date, the molecular mechanisms regulating daily and seasonal physiology are largely unknown despite the strong commercial relevance in the Atlantic salmon. In the Atlantic salmon, Davie et al (2009) was the first to report the photoperiod dependent circadian expression of clock genes (Clock, Bmal and Per2 and Cry2) in the brain of the Atlantic salmon. In the same investigation the expression of clock genes was reported in a wide variety of peripheral tissues, however 24h profiles of expression in peripheral tissues were not characterised. In order to examine further the role of seasonal photoperiod on the circadian expression of clock genes, the present work first aimed to characterise diel profiles of Clock, Per1 and Per 2 expression in the brain together with plasma melatonin levels in II Atlantic salmon acclimated to either long day (LD), short day (SD), 12L:12D (referred to as experiment 1 throughout) and SNP (referred to as experiment 2 throughout). Photoperiod dependent clocks were also investigated in peripheral tissues, namely in the fin and liver. Results showed circadian profiles of melatonin under all photoperiods. In experiment 1 both Clock and Per2 displayed significant circadian expression in fish exposed to LD. This is in contrast to previous results where rhythmic clock gene expression was observed under SD. In addition, clock gene expression differed in response to experimental photoperiod in the liver, and diel rhythm differed to that of the brain. No rhythmic expression was observed in the fin. Levels of plasma melatonin exhibited a circadian rhythm peaking during the nocturnal phase as expected. However the amplitude of nocturnal melatonin was significantly elevated under LD (experiment 1) and the SNP long day photoperiod and 2010 autumnal equinox samples (experiment 2). Overall results from these experiments suggested that the control of clock gene expression would be photoperiod dependent in the brain and the liver however photoperiod history is also likely to influence clock gene expression. Interestingly, the gradual seasonal changes in photoperiod under SNP did not elicit similar profiles of clock gene expression as compared to experimental seasonal photoperiods and clock gene expression differed between experimental photoperiod and SNP treatments. In experiment 2 significant seasonal differences were also observed in the amplitude of individual clock gene expression. The mechanisms underlying this and potential impact on seasonal physiology are unknown. Developmental changes such as the smoltification process or abiotic factors such as temperature or salinity should be further investigated. In mammals previous work has focused on the molecular switch for photoperiod response and regulation of thyroid hormone bioactivity via deiodinase mediated conversion of T4 to the biologically active form T3. In mammals and birds expression of key seasonal molecular markers i.e. Tsh, Eya3 and Dio2, are up-regulated hours after exposure to the first LD and III persist under chronic LD conditions. In order to confirm the involvement of these genes in the seasonal photoperiodic response in salmon, a microarray study was first carried out. Results displayed transcriptome level differences in the seasonal expression of a wide variety of target genes including Eya3 and Dio1-3 in relation to LD and SD photoperiod suggesting that these genes may have a conserved role in salmon. qPCR validations of selected genes of interest were then performed (Dio1, Dio2 and Dio3, Eya3 and Tshover diel cycles in fish exposed to LD and SD photoperiod (autumn acclimated fish). In addition an unrelated qPCR study was undertaken in salmon parr acclimated to LD, 12L12D and SD photoperiod (spring acclimated fish)(Dio2, Eya3 and Tsh. Consistent with findings obtained in other vertebrate species, circadian expression of Dio2 was observed under LD. However expression of Eya3 and Tsh appeared to be dependent on photoperiod history prior to acclimation to the experimental photoperiods as already suggested for clock gene expression in this thesis. This is potentially a consequence of direct regulation by clock genes. To our knowledge, this is the first report on the expression of key molecular components that drive vertebrate seasonal rhythms in a salmonid species. The thesis then focused on another key component of the photoneuroendocrine axis in fish, the pineal organ. In the Atlantic salmon, as in other teleosts the photoreceptive pineal organ is considered by many to be essential to the generation, synchronisation and maintenance of circadian and seasonal rhythms. This would be primarily achieved via the action of melatonin although direct evidence is still lacking in fish. In salmonids the production of pineal melatonin is regulated directly by light and levels are continually elevated under constant darkness. In non salmonid teleosts the rhythmic high at night/ low during day melatonin levels persists endogenously under constant conditions and is hypothesised to be governed by light and intra- pineal clocks. The aims of the present in vitro and in vivo trials were to determine if circadian clocks and Aanat2 expression, the rate limiting enzyme for melatonin IV production, are present in salmon, test the ability of the pineal to independently re-entrain itself to a different photoperiod and establish whether the candidate clock genes and Aanat2 expression can be sustained under un-entrained conditions. Expression of clock genes was first studied in vitro with pineal organs exposed to either 12L:12D photoperiod, reversed 12D:12L photoperiod and 24D. Clock gene expression was also determined in vivo, in fish exposed to 12L:12D. Results were then contrasted with an in vitro (12L:12D) investigation in the European seabass, a species displaying endogenous melatonin synthesis. Results revealed no rhythmic clock gene (Clock, per1 and per2) expression in isolated salmon pineals in culture under any of the culture conditions. In the seabass, Clock and Per1 did not also display circadian expression in vitro. However rhythmic expression of Cry2 and Per1 was observed in vivo in the salmon pineal. This suggested some degree of extra-pineal regulation of clocks in the Atlantic salmon. In terms of Aanat2 no rhythmic expression was observed in the Atlantic salmon under any experimental conditions while rhythmic expression of Aanat2 mRNA was observed in seabass pineals. This is consistent with the hypothesis that in salmonids AANAT2 is regulated directly at the protein level by light while in other teleosts, such as seabass, AANAT2 is also regulated by clocks at a transcriptional level.
5
Wilson, Byron Sanders. "Latitudinal variation in the ecology of a lizard : seasonal differences in mortality and physiology /." Thesis, Connect to this title online; UW restricted, 1990. http://hdl.handle.net/1773/5213.
6
Brockington, Simon. "The seasonal ecology and physiology of Sterechinus neumayeri (Echinodermata: Echinoidea) at Adelaide Island, Antarctica." Thesis, Open University, 2001. http://oro.open.ac.uk/58168/.
Анотація:
This study used an energy budget approach to record changes in the biology of the Antarctic sea urchin Sterechinus neumayeri in relation to environmental seasonality (i. e changes in chlorophyll standing stock and seawater temperature) over an unbroken two year period. Chlorophyll standing stock showed a brief but intense bloom each austral summer which contrasted with prolonged winter minima. Benthic chlorophyll standing stock, as recorded from sediment cores showed a similar cycle. Seawater temperature varied between -1.8°C and +1.2°C. Feeding activity was highly seasonal and closely correlated to chlorophyll standing stock. Feeding ceased during the austral winter of 1997 and 1998 for 6 and 4 months respectively. Metabolism, as measured by oxygen consumption and also ammonia excretion showed strong seasonality, with relatively brief 3 to 4 month periods of elevated activity in the austral summer contrasting with prolonged winter dormancy. Laboratory studies indicated that only 10-15% of the 3 fold seasonal rise in metabolism was caused directly by temperature (Q10=2.5) and that 80- 85% was related to increased physiological activity associated with feeding. Growth rate was measured over one year and was very slow. Comparison with other studies indicated that echinoid growth rate is strongly dependent on food availability, but that maximal growth rate is limited by seawater temperature, or by a co-varying factor. S. neumayeri is an annual spawner and histology was used to describe both the vitellogenic cycle and also to calculate reproductive output. Comparison with other published studies worldwide indicated that reproductive output is highly dependent on food availability, and that maximal reproductive output is not limited by temperature. Although the overall P: B ratio was low, the ratio of reproductive production to total production was higher than expected. These results indicated that due to the low metabolic rate only 12-16% of total body energy levels were used to endure the prolonged non-feeding polar winter. The overall annual growth efficiency was greater than for warmer water species, due to the larger relative contribution to reproductive output.
7
Zysling, Devin A. "The role of energetic trade-offs associated with seasonal variation in immune function." [Bloomington, Ind.] : Indiana University, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3344617.
Анотація:
Thesis (Ph.D.)--Indiana University, Dept. of Biology, 2008.Title from PDF t.p. (viewed on Oct. 8, 2009). Source: Dissertation Abstracts International, Volume: 70-02, Section: B, page: 0774. Adviser: Gregory E. Demas.
8
Welman, Shaun. "Seasonal changes in the heat production of an African small mammal, Rhabdomys pumilio." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/21417.
Анотація:
Endothermy refers to the ability of an individual to produce heat from internal sources, and allows animals to maintain a body temperature that is higher than their external environment. Although much is known about the benefits of endothermy, its origin is highly debated. Nonetheless, due to environmental variation, endotherms have to regulate their heat production (thermogenesis) in order to remain normothermic. An endotherms regulatory response seems to be body size dependent. Keeping warm during cold periods is energetically expensive, and for small mammals this is exacerbated by their high rate of heat loss due to high surface area to volume ratios. To compensate for the heat lost, small non-hibernating mammals must increase their level of thermogenesis. Much of our current understanding of thermogenic responses of small mammals is derived from laboratory acclimated animals, and studies on naturally acclimatized animals are uncommon. In addition, most studies on thermogenesis tend to focus on one level of animal organisation, such as subcellular, tissue or in-vivo, but seldom integrate these data. The aim of this study was to measure year-round variation in thermogenesis across all levels of organisation, using naturally acclimatized Rhabdomys pumilio individuals from the Nelson Mandela Metropolitan University, Port Elizabeth. It was predicted that the level of thermogenesis would be significantly higher during winter relative to other seasons in order to cope with the low ambient temperatures (Tas) experienced during this season. Open flow respirometry was used to measure the animal's oxygen consumption, as a proxy for metabolism; the by product of which is heat production. The animal's basal metabolic rate (BMR), nonshivering thermogenesis (NST) capacity and summit metabolic rate (MSUM) were measured. A Western blot analysis was used to determine the expression of uncoupling protein 1 (UCP 1) in the animals' brown adipose tissue (BAT), as well as determine its relative concentration. The cytochrome c oxidase (COX) activity of the animals' visceral organs and BAT was measured, as an indicator of the tissues' metabolic activity. COX activity was determined as the difference in the tissues' oxygen consumption before and after the addition of horse cytochrome c.
9
Durand, Mireille Françoise. "Total and Timothy grass pollen specific salivary immunoglobulin A in physiology and seasonal alergic rhinitis." Thesis, University of Wolverhampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405053.
10
Polites, Harry Gregory. "The Respiratory Response of Busycon canaliculatum (L) to Seasonal Variation of Water Temperature, Salinity, and Oxygen." W&M ScholarWorks, 1987. https://scholarworks.wm.edu/etd/1539625387.
11
Pattinson, Nicholas Bruce. "Seasonal physiological and behavioural responses of a small bird in a hot, arid habitat." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/19728.
Анотація:
The role that climate plays in the ecology of organisms is perhaps the most pronounced where the earth’s environments are most extreme. In arid-zones, organisms have to deal with large seasonal shifts and/or extremes in temperature and/or moisture levels. As a result, arid-zone species are sensitive to climatic changes. I assessed the physiological and behavioural adjustments of an arid-zone endemic passerine, the rufous-eared warbler (Malcorus pectoralis), to seasonal changes in the Karoo semi-desert of South Africa. Respirometry measurements in the field showed that the warblers’ basal metabolic rate was lower and set point body temperature (Tb) was higher in summer compared to winter. At high air temperatures (Ta) evaporative water loss (EWL) rate was significantly lower in summer compared to winter, while Tb showed a clear pattern of heterothermy that was similar in both seasons. Compared to winter, the warblers in summer were able to remain calm, and tolerate higher Ta’s, before their Tb’s increased to potentially detrimental levels. Behavioural observations showed that free-living warblers exhibited significant temperature-dependence in their behaviour; they increased panting behaviour, and reduced activity levels, time spent preening, and foraging effort at high Ta’s in summer. The warblers also displayed a considerable decrease in foraging success, and a shift in microsite use, at high Ta’s in summer. I hypothesise that the flexible responses the rufous-eared warblers show are aimed at increasing their heat tolerance in summer, and help them balance their energy and water demands in an arid environment that exhibits wide seasonality in Ta, in addition to high summer Ta. My findings emphasise the importance of identifying, as well as understanding, the associated costs of physiological and behavioural responses to environmental variables. This information is valuable in terms of predicting biologically meaningful responses (and hence, vulnerability) of arid-zone avian communities to climactic shifts.
12
Greives, Timothy J. "The role of kisspeptin in the regulation of seasonal reproduction in Siberian hamsters (Phodopus sungorus)." [Bloomington, Ind.] : Indiana University, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3378351.
Анотація:
Thesis (Ph.D.)--Indiana University, Dept. of Biology, 2009.Title from PDF t.p. (viewed on Jul 8, 2010). Source: Dissertation Abstracts International, Volume: 70-10, Section: B, page: 5920. Adviser: Gregory E. Demas.
13
Collingsworth, Michael Geoffrey Roy. "Endocrine changes associated with the onset of puberty and seasonal changes in the reproductive status of pony stallions." Thesis, Liverpool John Moores University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327660.
14
Weissenfluh, Shawn Edward. "Quantifying Seasonal Variation in Physiological Condition of Adult Franklin's Gull (Luecophaeus Pipixcan) during Nesting." Thesis, North Dakota State University, 2011. https://hdl.handle.net/10365/28844.
Анотація:
Understanding seasonal variation in adult physiological condition is important for developing hypotheses on how nest initiation, adult condition, chick development and recruitment are related in Franklin's gull and other migratory species of the northern plains. The purpose of this study was to profile physiological condition during the breeding season in nesting Franklin's gull (Luecophaeus pipixcan) adults. Physiological condition was quantified in nesting adults through four metrics: body measurements recorded from live-trapped birds, the corticosterone stress response measured from blood samples collected serially from live-trapped birds, and two measures of immune function (antimicrobial capacity of plasma from blood samples and heterophil/lymphocyte ratios based on blood smears, both taken from live-trapped birds). Physiological condition declined across the breeding season, as shown by a decline in body condition, stress tolerance and immune performance. Specifically, residual body mass decreased and exposure of the sternum keel increased with the progression of the breeding season. Additionally, birds nesting later in the season showed greater maximum corticosterone concentrations in the stress profile along with lower antimicrobial capacity. These results suggest two hypotheses: 1) that timing of nesting has a significant impact on the physiological condition of Franklin's gull and 2) that birds in poorer condition initiate breeding later in the season. Seasonal variation in condition may be related to time constraints observed in temperate latitudes and whether these birds are capital (i.e., acquiring resources outside the breeding area) or income (i.e., acquiring resources locally) breeders. Thus, determining physiological condition during the breeding season is an important step in elucidating how nest initiation, adult condition, chick development and recruitment are related in Franklin's gull.North Dakota Game and Fish Department
15
Jeanniard, Du Dot Tiphaine. "Diet quality and season affect physiology and energetic priorities of captive Steller sea lions during and after periods of nutritional stress." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/404.
Анотація:
The ability of animals to contend with unpredictable seasonal shifts in quality and quantity of prey has implications for the conservation of wildlife. Steller sea lions(Eumetopias jubatus) were subjected to different quantities and qualities of food to determine what physiological and endocrine responses would occur and whether they differed between season (summer and winter) or diet (high-lipid Pacific herring Clupeapallasi vs. low-lipid Walleye Pollock Theragra chalcogramma). Eight females were divided among two groups. One (Group H) were fed herring for 28 days (baseline), then received a reduced caloric intake for a subsequent 28 days (restriction) to induce a 15%loss of body mass. The second (Group P) were also fed herring during the baseline followed by a reduced isocaloric diet of pollock during the restriction. Both groups subsequently returned to their baseline intake of herring for a 28-day controlled re-feeding. The two groups of sea lions lost identical mass during restrictions independent of species eaten, but did differ in the type of internal energy reserve (protein vs. lipids) they predominantly used. Group H lost significantly more lipids and less lean mass than Group P in both seasons. In summer, Group H also increased activity levels and decreased thermoregulation capacity to optimize energy allocation. No such changes were observed for Group P whose capacity to adjust to the reduced caloric intake seemed to have been blocked by the pollock diet. During winter, the sea lions spared energy allocated to activity (especially Group H) and preserved thermoregulation capacity. Changes in body mass was negatively related to free cortisol and positively related to IGF-1 in winter, but only IGF-1 was related to changes in mass in summer when lean mass regulation seemed more important. Levels of IGF-1 were associated with changes in protein metabolism in both seasons for both groups, but changes in body condition were never explained by the measured metabolites or hormones. The capacity to compensate for mass loss was seasonally dependent with sea lions displaying compensatory growth (by restoring lipid stores) in winter but not in summer. Summer appears to be a more difficult season for sea lions to recover from mild nutritional stress. These physiological findings can be used to refine bioenergetic models needed for the conservation of Steller sea lion populations.
16
Duckworth, Janine Alma. "Studies of seasonality in red deer (Cervus elaphus) : with special emphasis on the reproductive physiology of red deer hinds." Lincoln University, 1992. http://hdl.handle.net/10182/2267.
Анотація:
Four trials were conducted to investigate factors controlling the seasonal onset of reproductive activity in red deer hinds. Firstly (Chapter 4), the role of photorefractoriness to long daily photoperiods in the initiation of the seasonal reproductive activity in breeding red deer hinds was examined. Red deer hinds (n=10) were prematurely exposed to a long daily photoperiod of 15.3 h from 22 July to 8 November 1986 i.e. winter-spring (EPW), or maintained under natural photoperiods (NP). Six hinds experienced the natural changes in daily photoperiod until mid-summer but were exposed to a 15.5 h of light each day from 30 January to 30 April 1987, i.e. summer-autumn (EPS), whilst hinds in the other groups experienced naturally decreasing daily photoperiods. On 5 occasions (July 1986, January, February, March and April 1987), blood samples were collected from 4 NP and 4 EPW hinds every 20 minutes for 4 h to monitor secretion of luteinising hormone and half hourly for another 4 h following an i.v. injection of 2 µg GnRH to measure pituitary responsiveness. In January, March and April 1987 EPS hinds were also intensively sampled for 4 h. Plasma progesterone concentrations and mean date of calving indicated that the onset of breeding activity was not affected by light treatment in the EPW hinds but was delayed by 3 weeks in the EPS hinds. In contrast, supplementary lighting caused a premature elevation of plasma prolactin concentrations and advanced pelage moulting in EPW hinds only. Plasma LH secretion patterns indicated that LH pulse frequency and mean LH concentrations were greater during the breeding season than during pregnancy or, seasonal or postpartum, anoestrus. The reduction in LH secretion was partially explained by a diminished pituitary responsiveness to GnRH. Daily plasma melatonin secretion patterns indicated that the duration of the nocturnal increase in melatonin concentrations was responsive to changes in photoperiod and provided a suitable endocrine signal for measuring day length. The results suggest that, unlike the sheep and prepubertal red deer hind, the onset of seasonal breeding activity in breeding red deer hinds is not affected by long daily photoperiods in spring but is delayed if the autumnal decrease in daily photoperiod is delayed. Therefore neither the development of photorefractoriness nor the spring increase in daily photoperiods initiated the transition from seasonal anoestrus to reproductive activity in the breeding hind. However, long daily photoperiods may have entrained the annual cycle of pelage shedding and prolactin secretion. It is possible that the neuroendocrine pathway by which photoperiodic signals entrain the seasonal cycle of reproduction is separate from those which regulate other seasonal events in the breeding red deer hind. Secondly (Chapter 5), in a study of seasonality of reproduction, 4 pubertal hinds were monitored for live weight and plasma LH and progesterone concentrations from December 1987 to October 1988 (i.e. 12-22 months of age). In addition the pattern of LH secretion was also studied in 4 ovariectomised pubertal hinds implanted s.c. with controlled release implants containing 12 mg oestradiol-17β between 4 March and 25 May and between 15 June and 19 September, 1988. On several occasions (15 December, 29 February, 15 March, 24 April, 14 June, 29 June, 18 September (all hinds) and 3 October (ovariectomised hinds only) blood samples were collected every 20 minutes for 4 h to monitor secretion of luteinising hormone and following an i.v. injection of 2 µg GnRH to measure pituitary responsiveness. Plasma progesterone profiles indicated that 4-6 ovarian cycles, lasting about 19 d each, occurred in each intact hind. Regular ovarian cycles commenced in late April (26 April ± 3.4 d, mean ± s.e.m.) and ceased 3 months later in July (21 July ± 7.2 d). The number of LH pulses in the intact hinds was higher in June (1-2 pulses/4 h) than in the non-breeding season (< 1 pulse/4 h) probably due to a seasonal increase in GnRH secretion. It appears that the seasonal increase in LH pulsatility and onset of reproductive activity in the entire hinds were temporally related to a reduction in the sensitivity of LH secretion to the negative feedback effects of oestradiol in ovariectomised pubertal hinds. In the third trial (Chapter 6), 20 male and 20 female red deer calves were immunised at birth against a melatonin conjugate or injected with adjuvant only (controls). Booster injections were given on 5 occasions over the next 2 years. Stags which produced significant melatonin binding activity in response to immunisation, were heavier than the controls between 7 and 11 months of age and at 16, 20, 30 and 34 months of age. A similar but smaller effect on live weight was seen in the immunised hinds. Immunisation against melatonin did not affect the calving date of the hinds or antler development and time of casting of antlers in the stags. These results indicated that disruption of the photoperiodic signal by immunisation against melatonin may have prevented the entrainment of annual rhythms in feed intake and growth but without affecting the seasonal cycles in antler growth and ovarian activity. Finally in a series of 3 trials (Chapter 7), anoestrous red deer hinds were induced to ovulate with the GnRH analogue, buserelin. Hinds were pre-treated with intravaginal devices containing 0.6 g progesterone (CIDR-Type S) for 14 days prior to CIDR withdrawal on 4 March. In Year 1, 15 hinds were treated with 1 CIDR each and 8 hinds were injected i.m. with 4 µg buserelin (a GnRH analogue) at CIDR removal followed by 2nd injection of 10 µg 48 h later. In Year 2, 16 hinds were treated with 2 CIDRs each and 8 hinds were injected Lm. with 4, 3, 2, 2 and 10 µg buserelin at -48, -24, 0, 24 and 48 h respectively from CIDR withdrawal. In Year 3, 15 hinds were treated with 2 CIDRs and 11 hinds (Groups Band BO) injected with buserelin identical to the protocol in Year 2. At CIDR withdrawal 6 of these buserelin treated hinds (Group BO) and 4 other progesterone-primed hinds (Group 0) were injected with 500 µg oestradiol benzoate. In addition, during the breeding season, 4 hinds (Group C) were treated with double CIDRs only for 14 d from 1 April. When oestrous behaviour and the pattern of plasma LH secretion were monitored in Year 3, oestrous behaviour was less noticeable and delayed in Group B hinds and peak LH levels were lower and increased later relative to Group 0, BO and C hinds. Two weeks after CIDR withdrawal, 6 buserelin-treated hinds in both Year 1 and Year 2, and 3/5 B, 2/4 0, 3/6 BO and 4/4 C group hinds in Year 3 had a single corpus luteum present. Plasma progesterone concentrations were elevated for about 12 d in most hinds with a corpus luteum in Year 2 and in most B, BO and C Group hinds in Year 3. However, progesterone secretion was low in several Year 1 and all Group 0 hinds in Year 3 indicating that the induced corpora lutea in these hinds were functionally subnormal. There was no evidence that any of the buserelin-induced ovulations resulted in pregnancy, probably because the induced ovulations were not accompanied by normal hormonal and behavioural patterns. The experiments described in this thesis have contributed to our understanding of the regulation of seasonal breeding in red deer hinds. This knowledge may eventually enable reproductive activity to be effectively manipulated, thereby improving the efficiency of deer production systems.
17
Williams, Jason. "Links Between Desiccation Resistance and Cold-Tolerance in an Overwintering Insect: Seasonal and Geographic Trends." Miami University / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=miami1124223034.
18
Pustina, Andrew A. "Seasonal Perceived Training Load in NCAA DI Men’s Soccer: Is There a Dose-Response Relationship?" Digital Commons @ East Tennessee State University, 2016. https://dc.etsu.edu/etd/3086.
Анотація:
The purpose of this dissertation was to determine if a there was a dose-response relationship across an NCAA Division I men’s soccer season. Specifically, this dissertation serves to: 1.) assess the validity of duration measurements that have previously been used to calculate session RPE during competitive matches, 2.) determine the degree and magnitude of change in intermittent endurance performance across a season and to observe how change in endurance relates with training load, 3.) determine the degree and magnitude of change in strength and explosiveness across a season, and to see how these strength changes relate to training load. 1.) Minutes played were found to be the most accurate duration for calculating session RPE during men’s NCAA Division I soccer matches. 2.) Endurance performance, measured using the Yo-Yo IR1, increased by an average of 14 percent from pre to post season. Furthermore, a large, negative relationship was observed between training load and change endurance performance. These relationships suggest that excessive accumulation of training load can impair endurance performance. The congested NCAA DI match schedule may make it difficult to prevent excessive training loads. 3.) When players were grouped by amount of college soccer experience (upper and underclassmen), upperclassmen jumped significantly higher than underclassmen during the preseason. Moreover, the upperclassmen maintained or increased jump height from pre to post season, while underclassmen experienced a general decrease in jump height from pre to post season. Moderate relationships indicate a positive relationship between training load from resistance training and changes in strength. Likewise, these same relationships strengthened in the players who received more playing time during matches. Taken together, the high numbers of moderate relationships indicate a high level of individual variability. Dose-response relationships with strength variables were not sufficiently established. The overall findings of this dissertation provide evidence that subjectively and objectively monitoring training load and soccer-related performance variables can assist coaches in making decisions that will promote the welfare of their team.
19
Wu, Jin. "How do Amazonian Tropical Forest Systems Photosynthesize under Seasonal Climatic Variability: Insights from Tropical Phenology." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/594653.
Анотація:
Amazonian evergreen forests are of broad interest, attributable to their ecological, economic, aesthetic, and cultural importance. However, their fate under climate change remains uncertain, largely due to unclear mechanisms in regulating tropical photosynthetic metabolism. Understanding mechanistic controls on these dynamics across time scales (e.g. hours to years) is essential and a prerequisite for realistically predicting tropical forest responses to inter-annual and longer-term climate variation and change. Tropical forest photosynthesis can be conceptualized as being driven by two interacting causes: variation due to changes in environmental drivers (e.g. solar radiation, diffuse light fraction, and vapor pressure deficit) interacting with model parameters that govern photosynthetic behavior, and variation in photosynthetic capacity (PC) due to changes in the parameters themselves. In this thesis, I aim to reveal photosynthetic controls by addressing three fundamental but complementary questions: (1) What are the mechanisms by which the subtle tropical phenology exert controls on tropical photosynthetic seasonality? (2) How do the extrinsic and intrinsic controls regulate the photosynthesis processes at hourly to interannual time scales in an Amazonian evergreen forest? (3) Are there sufficiently consistent relations among leaf traits, ages, and spectra that allow a single model predict the leaf aging process of Amazonian evergreen trees? To address question 1, I firstly show that seasonal change in ecosystem-scale photosynthetic capacity (PC), rather than environmental drivers, is the primary driver of seasonality of gross primary productivity (GPP) at four Amazonian evergreen forests spanning gradients in rainfall seasonality, forest composition, and flux seasonality. Using novel near-surface camera-detected leaf phenology to drive a simple leaf-cohort canopy model at two of these sites, I further show that leaf ontogeny and demography explain the changes in ecosystem photosynthetic capacity. The coordination of new leaf growth and old leaf divestment (litterfall) during the dry season shifts canopy composition towards younger leaves with higher photosynthetic capacity, driving large seasonal increases (~27%) in ecosystem photosynthetic capacity. To address question 2, I used the 7-year eddy covariance (EC) measurements in an Amazonian tropical evergreen forest. I used a statistical model to partition the variability of 7-year EC-derived GPP into two main causes: variation due to changes in extrinsic environmental drivers and variation in intrinsic PC. The fitted model well predicts variability in EC-derived GPP at hourly (R²=0.71) to interannaul (R²=0.81) timescales. Attributing model predictions to causal factors at different timescales, I find that ~92% of the variability in modeled hourly GPP could be attributed to environmental driver variability, and ~5% to variability in PC. When aggregating the modeled GPP into the annual time-step, the attribution is reversed (only ~4% to environment and ~91% to PC). These results challenge conventional approaches for modeling evergreen forests, which neglect intrinsic controls on PC and assume that the primary photosynthetic control at both long and short timescales is due to changes in the hourly-to-diurnal environment on the physiological phenotype. This work thus highlights the importance of accounting for differential regulation of different components of GPP at different timescales, and of identifying the underlying feedbacks and adaptive mechanisms which regulate them. To address question 3, I explored the potential for a general spectrally based leaf age model across tropical sites and within the vertical canopy profiles using a phenological dataset of 1831 leaves collected at two lowland Amazonian forests in Peru (12 species) and Brazil (11 species). This work shows that a simple model (parameterized using only Peruvian canopy leaves) successfully predicts ages of canopy leaves from both Peru (R²=0.83) and Brazil (R²=0.77), but ages for Brazilian understory leaves with significantly different growth environment and leaf trait values have lower prediction accuracy (R²=0.48). Prediction accuracy for all Brazilian samples is improved when information on growth environment and leaf traits were added into the model (5% R² increase; R²=0.69), or when leaves from the full range of trait values are used to parameterize the model (15% R² increase; R²=0.79). This work shows that fundamental ecophysiological rules constrain leaf traits and spectra to develop consistently across species and growth environment, providing a basis for a general model associating leaf age with spectra in tropical forests. In sum, in this thesis, I (1) conceptualize photosynthesis as being driven by two interacting dynamics, extrinsic and intrinsic, (2) propose and validate a model for biological mechanisms that mediate seasonal dynamics of tropical forest photosynthesis, (3) assess and quantify the factors controlling tropical forest photosynthesis on timescales from hourly to interannual, and (4) develop a general model for monitoring leaf aging processes of tropical trees across sites and growth environments. The revealed mechanisms (and proposed models) in this thesis greatly improve our mechanistic understanding of the photosynthetic and phenological processes in tropical evergreen forests. Strategic incorporation of these mechanisms will improve ecological, evolutionary and earth system theories describing tropical forests structure and function, allowing more accurate representation of forest dynamics and feedbacks to climate in earth system models.
20
Pyter, Leah M. "Seasonal plasticity of physiological systems, brain, and behavior." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1141319505.
21
Stahl, Michael T. "Reproductive physiology of shovelnose sturgeon from the middle Mississippi River in relation to seasonal variation in plasma sex steroids, vitellogenin, calcium, and oocyte diameters /." Available to subscribers only, 2008. http://proquest.umi.com/pqdweb?did=1594478351&sid=2&Fmt=2&clientId=1509&RQT=309&VName=PQD.
22
Burdick, Timothy E. "Seasonal effects of elevated carbon dioxide, competition, and water stress on gas exchange and growth of loblolly pine and sweetgum grown in open-top chambers." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-11182008-063327/.
23
Rosendale, Andrew J. "Importance of Facilitative Urea Transporters in Anuran Osmoregulation." Miami University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=miami1313089167.
24
Freese, Daniela [Verfasser], Barbara Akademischer Betreuer] Niehoff, and Wilhelm [Akademischer Betreuer] [Hagen. "Life history traits of copepods in a changing Arctic : seasonal patterns in the physiology of Calanus glacialis [[Elektronische Ressource]] / Daniela Freese. Gutachter: Barbara Niehoff ; Wilhelm Hagen. Betreuer: Barbara Niehoff." Bremen : Staats- und Universitätsbibliothek Bremen, 2015. http://d-nb.info/1075609275/34.
25
Parker, Scott Landsborough. "Thermal and reproductive biology of the lizards sceloporus occidentalis and sceloporus graciosus along an environmental and geographical gradient." CSUSB ScholarWorks, 2001. https://scholarworks.lib.csusb.edu/etd-project/2010.
Анотація:
The thermal environment exerts a strong influence on many aspectsof squamate life history. Environmental temperatures constrain daily activity time, fecundity, growth rate, and also influences hatchling phenotype. Cold nest temperatures can slow the development of eggs deposited in the soil, cause developmental abnormalities or result in mortality of embryos.
26
Moser, Jonathan G. "Cold Season Physiology of Arctic Plants." FIU Digital Commons, 2012. http://digitalcommons.fiu.edu/etd/750.
Анотація:
The cold season in the Arctic extends over eight to nine months during which ecosystem gas exchange and water balance of arctic plants have been largely unexplored. The overall objective of this thesis was to examine two critical gaps in our knowledge about tundra cold season processes – ecosystem respiration at very low temperatures and water uptake during the winter-spring transition. I determined the temperature response of ecosystem respiration of tundra monoliths down to temperatures as low as can be expected under snow-covered conditions (-15 °C). Temperature responses fit the Arrhenius function well with Q10 values over the range of -15 to 15 °C varying from 6.1 to 4.8. I used deuterium-enriched water (2H2O) as a tracer to evaluate water uptake of evergreen plants at snowmelt when soils are largely frozen. The results revealed that evergreen plants take up water under snow cover, possibly via roots but undoubtedly by foliar uptake.
27
Caylor, Danielle. "InHabit: Physiology and Architecture in Time." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1367927909.
28
Leclercq, Bastien. "Rôle de la rétine dans les fonctions non-visuelles : traitement des informations relatives à la photopériode et impact de la lumière bleue sur le comportement." Thesis, Strasbourg, 2021. http://www.theses.fr/2021STRAJ099.
Анотація:
Les cellules ganglionnaires intrinsèquement photosensibles (ipRGCs) constituent une interface majeure dans la régulation de la physiologie et des comportements par la lumière. Ces travaux démontrent que la présence de ces cellules dans la rétine est suffisante pour permettre à des souris d’intégrer les variations saisonnières de la photopériode. De plus, nous décrivons des modifications dépendantes de la photopériode au sein des ipRGCs. Ces résultats suggèrent que la rétine pourrait intégrer les variations de la photopériode, afin d’assurer au mieux les fonctions visuelles et non-visuelles à travers les saisons. Par ailleurs, ces travaux ont exploré les effets de la surexposition aux écrans et notamment à un enrichissement en lumière bleue sur le comportement de type anxieux/agressif. Les ipRGCs, sensibles à la lumière bleue (460-480nm), sont connectées avec de nombreuses structures cérébrales impliquées dans la régulation des comportements. Nos résultats montrent qu’une exposition prolongée à un environnement enrichi en lumière bleue peut modifier les comportements de type agressifThe intrinsically photosensitive retinal ganglion cells (ipRGCs) constitute a key interface in the regulation of our physiology and behaviours by light. First, this thesis demonstrates that the ipRGCs are sufficient to ensure a normal photoperiod integration. Mice without rods nor cones still encode photoperiod variation through melatonin secretion and display photoperiod-dependent locomotor activity changes. This is the first time we describe photoperiod-dependent changes of the ipRGCs. These data suggest that the retina itself could integrate the photoperiod locally, and thus constitute an adaptative mechanism to regulate both visual and non-visual functions depending on the seasons. Secondly, this thesis assessed the effects of screen overexposure and notably to blue light enrichment on aggressive/anxious behaviour. ipRGCs are particularly sensitive to blue light (460-480nm) and are connected to various brain structures involved in behaviour regulation. We show that exposure to a blue light-enriched environment can modify behaviour such as aggressiveness
29
Tierney, Lindsey Kathryn Lindsey Kathryn Tierney. "Surface facial electromyography reactions to light-relevant and season-relevant stimuli in seasonal affective disorder /." Download the dissertation in PDF, 2005. http://www.lrc.usuhs.mil/dissertations/pdf/Lindsey2005.pdf.
30
Madakadze, Ignacio Casper. "Physiology, productivity and utilisation of warm season (C4) grasses in a short growing season area." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34661.
Анотація:
Warm season grasses are increasingly being cultivated in North America for summer forage, soil conservation, and biomass production. In more northern environments, temperature and length of growing season have an overriding effect on the productivity of warm season grasses. There is limited information on the adaptability and production potential of warm season grasses in these short season areas. A study was conducted in south-western Quebec from 1993 to 1996 to evaluate the productivity of five species of warm season grasses. Phenological development, canopy leaf area development and architecture, radiation-use efficiency (RUE), yield and chemical composition were determined. In terms of phenology, there was a diversity of developmental patterns and the genotypes of greatest potential were characterised by early spring growth and late onset of dormancy in fall. Most of the genotypes that were early in spring growth were also early maturing and low yielding. Late maturing genotypes were generally late in spring growth, high yielding and generally of southern origin. Differences in developmental patterns were partly explained by differences in base temperatures for germination and growth, and growth rates. Seed osmoconditioning and/or matriconditioning alleviated effects of low temperatures on switchgrass seed germination and potential establishment. Maximum leaf area index ranged from 6.1 to 8 and the vertical leaf area distributions and light interception levels varied among genotypes. Average end of season biomass yields ranged from 8.5 to 14.4 Mg ha-1. Switchgrass rates of DM accumulation ranged from 175 to 191 kg ha-1 day-1 and RUE 0.89 to 1.1 g MJ-1 of incoming solar radiation. Moderate amounts of N fertilisation increased yield and quality of switchgrass, which could be harvested in a 2-cut system. NDF and ADF ranged from 77--88 and 46--57% respectively, and showed a rapid increase to a mid season plateau. Nitrogen concentrations declined curvilinearly wit
31
Madakadze, Ignacio Casper. "Physiology, productivity and utilisation of warm season (C¦4) grasses in a short growing season area." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0017/NQ37002.pdf.
32
Markezich, Allan Louis Riddle Wayne A. "Late season physiological adaptations of two syntopic araneid spiders." Normal, Ill. Illinois State University, 1987. http://wwwlib.umi.com/cr/ilstu/fullcit?p8726505.
Анотація:
Thesis (Ph. D.)--Illinois State University, 1987.Title from title page screen, viewed August 16, 2005. Dissertation Committee: Wayne A. Riddle (chair), D. Reed Jensen, Steven A. Juliano, Charles F. Thompson, James N. Tone. Includes bibliographical references (leaves 103-118) and abstract. Also available in print.
33
Tran, Michaellong. "Senescence of native perennial warm season grasses. senescence associated switchgrass transcriptome." Thesis, South Dakota State University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10109440.
Анотація:
Senescence of perennial crops enable continuous harvests after one sowing event. Perennials senesce at adapted rates of their native environments; however, early senescencing crops do not maximize the growing season as nutrient reallocation takes precedence. Chlorophyll degradation and nitrogen reallocation was observed to occur rapidly between mid to late September. Transcriptome analysis on early and late senescencing switchgrass cultivars reveals upregulation of starch metabolism, light reactions, Calvin-Benson Cycle, and anthocyanin synthesis in late senescencing switchgrass. Morphological variations between the two germplasms prolong the growing season of late senescencing switchgrass, maximizing yield. Expression of mRNA as senescence progresses and between the two genotypes reveals potential targets and genes of interest for crop breeding techniques to maximize the growing season of perennial crops, optimize nutrient reallocation, and enhance yield.
34
Rethwisch, Michael D., Nathan Rovey, Nathan Heeringa, and Aron Quist. "Comparison of Early Season and Mid-Season Applied Plant Growth Regulators on DPL 5415 Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/210758.
Анотація:
Several plant growth regulators were applied to DPL 5415 cotton to evaluate effectiveness on cotton lint yield. Growth regulators applied in small amounts over multiple applications early in the growing season reduced yields compared with the check while a single application applied at full-bloom slightly increased lint yields. High night time temperatures from late July into early September were detrimental for cotton production. Increased squaring of early season applications compared with the check may have resulted in reduced yields due to increased stress from temperatures and/or nutrient availability. Increased stress in the early treated (more fruit) plots may have had greater fruit abscission.
35
Nangle, Edward J. "Ultraviolet light and its effect on germination, growth, physiology and pigment responses of cool season turfgrasses." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1343741203.
36
Silvertooth, J. C., and E. R. Norton. "Evaluation of Late Season Pix™ Applications." College of Agriculture, University of Arizona (Tucson, AZ), 1997. http://hdl.handle.net/10150/210950.
Анотація:
The effects of late-season Pix™ on the growth characteristics and yield of Upland cotton was examined in this study. Three treatments were imposed late season (3447 HUAP), 1, a check plot, receiving no Pix™; 2 receiving 0.75 pt/acre, and 3; receiving 1 pt/acre. The imposed treatments did not have a statistically significant effect on plant growth characteristics or earliness, nor were there any significant overall yield differences detected among treatments.
37
Norton, E. R., and J. C. Silvertooth. "Evaluation of Late Season Pix™ Applications." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/210272.
Анотація:
The effects of late -season Palm on the growth characteristics and yield of Upland cotton was examined in this study. Three treatments were imposed late-season (3447 HUAP), 1, a check plot, receiving no Pix™, 2 receiving 0.75 pt/acre, and 3; receiving 1 pt/acre. The imposed treatments did not have a statistically significant effect on plant growth characteristics or earliness nor were there any significant overall yield differences detected among treatments.
38
Silvertooth, J. C., and A. Galadima. "Late Season Crop Management Effects on Fiber Micronaire." College of Agriculture, University of Arizona (Tucson, AZ), 2003. http://hdl.handle.net/10150/197730.
Анотація:
A field experiment was conducted during the 2002 growing season to evaluate a central Arizona grower’s method of addressing cotton fiber micronaire based on the management and timing of his agronomic inputs. The success of his inseason management, irrigation termination decision combined with his method of defoliation has led to a consistent production of premium fiber micronaire in recent years. Steps to accomplish crop defoliation and the subsequent mixing of seed cotton from the top (younger) and lower (older) bolls achieved at harvest are intended to keep the micronaire at premium levels and further prevent discounts on the crop. A companion study was conducted at the University of Arizona Maricopa Agricultural Center (MAC-1,175 ft. elevation) in an effort to duplicate the grower’s late season crop management operations. This study consisted of two treatments, a control (conventional) which received an application of 10 oz. Ginstar combined with ½ pt. surfactant in 20 gal./acre carrier and a treatment which received the conventional treatment in addition to a pre-defoliation Accelerate and a post-defoliation Gramoxone applications consistent with the grower’s methods. Plant growth and development measurements taken inseason revealed that height to node ratio (HNR) and fruit retention (FR) levels estimates were similar for both sites (grower fields and MAC study). Lint yield estimates indicated no difference between the conventional defoliation and the treatment receiving additional compounds at MAC. Results of the analyses performed on final micronaire data also indicated no significant difference in micronaire values between the two methods of defoliation and late season management at MAC. Fiber micronaire values exceeded the premium level (>5.0) for both treatments at MAC. However, results obtained from the cooperator-grower gin records revealed that average fiber micronaire for all of the fields monitored in this project were at premium level (<5.0).
39
Silvertooth, J. C., and A. Galadima. "Late Season Crop Management Effect on Fiber Micronaire." College of Agriculture, University of Arizona (Tucson, AZ), 2004. http://hdl.handle.net/10150/198124.
Анотація:
A field experiment was conducted during the 2002 and 2003 growing seasons to evaluate a central Arizona grower’s method of addressing high cotton fiber micronaire based on the management and timing of agronomic inputs. In-season management and irrigation termination combined with defoliation methods has led to consistent production of premium fiber micronaire in recent years. Steps to accomplish crop defoliation and the subsequent mixing of seed cotton from the top (younger) and lower (older) bolls achieved at harvest are intended to keep the micronaire at premium levels and further prevent discounts on the crop. A companion study was conducted in 2002 at the University of Arizona Maricopa Agricultural Center (MAC-1,175 ft. elevation) in an effort to duplicate the grower’s late season crop management operations. This study consisted of two treatments, a control (conventional) which received an application of 10 oz. Ginstar combined with 1/2 pt. surfactant in 20 gal./acre carrier and a treatment which received the conventional treatment in addition to a predefoliation of Accelerate and a post-defoliation of Gramoxone, consistent with the grower’s methods. At the grower’s location, data was collected during the 2002 and 2003 seasons. In 2002 and 2003, plant growth and development measurements taken in-season revealed that height to node ratio (HNR) and fruit retention (FR) levels tracked well and were similar for both sites and years (grower’s fields and MAC study). Lint yield estimates indicated no difference between conventional defoliation and the treatment receiving additional compounds at MAC in 2002. Average yield estimates were high for the cooperator-grower fields in both the 2002 and 2003 seasons. Results of the analysis performed on final micronaire data indicated no significant difference in micronaire values between the two methods of defoliation and late season management at MAC. In addition, fiber micronaire values exceeded the premium level (>5.0) for both treatments at MAC. In contrast, the data of 2002 and 2003 obtained from the cooperator-grower gin records revealed consistent results for average fiber micronaire for all of the fields monitored in this project which were at premium levels (<5.0).
40
Hillhouse, M. "Injury surveillance during the 2011 FNB varsity cup rugby season." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86485.
Анотація:
Thesis (MSc)--Stellenbosch University, 2014.ENGLISH ABSTRACT: OBJECTIVES: The primary objective was to establish and compare the injury incidence in forwards and backline players during the 2011 FNB Varsity Cup season. The secondary objective was to establish and compare the injury prevalence in forwards and backline players during the 2011 FNB Varsity Cup season. Lastly, to establish and compare the different training loads, types of injuries and injury rates amongst the various rugby teams during the 2011 FNB Varsity Cup. STUDY DESIGN: A retrospective, descriptive study was done to assess injury prevalence and incidence during the 2011 FNB Varsity Cup rugby (premier division) competition. PARTICIPANTS: Male rugby playing students, from eight teams. The total number of observed rugby players from the seven teams consisted of ±23 – 30 players, all between the ages of 18 and 25 years (23 ± 1.2 years). All players had to qualify according to the rules of the Varsity Cup 23,45. METHODS: The data collection procedure and injury definitions were aligned with the respective consensus statement for rugby injuries12. The injury surveillance included all injuries that were reported on the standardized IRB injury form (Addendum D), by each rugby team’s medical support staff. There were eight rugby teams partaking in the 2011 FNB Varsity cup, premier division tournament. The FNB Varsity cup took place at eight University venues in South Africa. The FNB Varsity Cup round robin began in February 2011 where games were played every Monday evenings over a seven to nine week period, on a home and away basis. The play-offs of the top four teams followed for two more weeks. Injury surveillance statistics were calculated and compared with training loads and the number of hours of exposure. Injury rates are expressed as the number of injuries sustained per 1000 hours a player is at risk. Descriptive statistics were used to report the prevalence and incidence of all injuries during the tournament. A significance level of p<0.05 was accepted. RESULTS: Seven out of the eight teams participating in the 2011 FNB Varsity Cup were able to submit injury and training statistics. Of these seven teams, there were 178 (6.1 injuries per 1000 hours) injuries in total reported throughout the season. 61 pre-season injuries were found (2.1 per 1000 hours) compared to 117 (4.0 per 1000 hours) in-season injuries reported. There were 125 match injuries (89 per 1000 hours) and 52 training injuries (1.58 per 1000 hours) which was statistically significant (p = 0.039). The total number of new injuries were 120 (4.1 per 1000 hours) with only 52 (2.0 per 1000 hours) recurrent. The lower limb was affected by 97.5% of the total injuries. Over-all the most injured sites showed a common trend, namely the ankle and foot with 15.9% and the head 15.3% of the total injuries. The shoulder (11.4%), hamstring (10.2%), knee (10.2%) and quadriceps (9.7%) were all similarly affected. The injury sites varied between forwards and backline players (forwards: 63.4% backline: 36.6%). The forwards most injured anatomical site showed a trend with the shoulder and ankle (0.5 per 1000 hours) being affected the most. The hamstring (0.4 per 1000 hours), ankle, head (0.3 per 1000 hours) and knee (0.2 per 1000 hours) were the most injured site amongst the backline players. The tackle was responsible for the cause of the majority of the injuries (total: 19.1 injuries per 1000 hours) amongst the forwards and backline players (forwards: 20.5 per 1000 hours backs: 13.6 per 1000 hours). The most common types of injuries were sprains (18.2 per 1000 hours) and strains (24.5 per 1000 hours) found amongst the forwards and backline players. The forwards had higher contusion and concussion (0.3 per 1000 hours) trend rates compared to the backline players. The backline had overall higher tendinopathy (0.2 per 1000 hours) trend rates. Amongst the forwards, the locks (15.2%) and props (12.9%) had the highest number of injuries and amongst the backline players were the wings (8.4%) and centres (9%) were the most injured players. The majority of the injuries occurred during the last part of the first half (26.7%) and the last part of the second half (30.7%). CONCLUSION: The prevalence and incidence of match injuries was significantly higher than during training (p = 0.039). Similarly to other injury surveillance studies, the tackle was the most dangerous phase of play. The Forwards who are more engaged in a greater number of physical collisions in a game resulted in more injuries compared to backline players 71. The backline players, due to their style of play had more running and accelerating injuries 5,24. Fatigue and other confounding factors such as a lack of physical conditioning, travel and academics could be a determinant to decreasing the threshold for injury’s occurring during the last part of each half of the game, during matches 22. Furthermore, the site, type and mechanism of injuries vary across individual playing positions as well as from team to team 24,26. This suggests that different training styles for the various positions should be recommended as an addition to an injury prevention protocol at this level of rugby.
AFRIKAANSE OPSOMMING: DOELWITTE: Die primêre doel van hierdie studie was om die beserings in voor- en agterspelers gedurende die 2011 FNB Universiteitsbeker seisoen vas te stel en te vergelyk. Die sekondêre doel was om die beserings in voorspelers en agterspelers gedurende die 2011 FNB Universiteitsbeker seisoen vas te stel en te vergelyk. Laastens, om die verskillende ladingsoefeninge, tipe beserings en hoeveelheid beserings onder die verskillende rugbyspelers gedurende die 2011 FNB Universiteitsbeker vas te stel en vergelyk. STUDIE ONTWERP: 'n Retrospektiewe beskrywende studie is gedoen waarin die geneigdheid tot, en die voorkoms van beserings gedurende die 2011 FNB Universiteitsrugby toernooi bepaal is. DEELNEMERS: Manlike studente rugbyspelers, vanaf agt spanne. Die totale aantal rugbyspelers wat geanaliseer was, was vanaf slegs sewe spanne, bestaande uit ± 23 - 30 spelers in elke span. Hierdie spelers was almal tussen die ouderdomme van 23 ± 1.2 jaar. Al die spelers moes 'n geregistreerde student by een van die agt deelnemende universiteite gewees het gedurende die toernooi regoor Suid-Afrika in 2011. METODE: Die data insamelingsproses en beseringsdefinisies is in lyn met die onderskeie konsensus ooreenkomste vir rugby beserings 12. Die besering opname sluit alle beserings in wat deur elke rugbyspan se mediese personeel op die gestandardiseerde IRB beseringsvorm aangedui is. Daar was agt deelnemende rugbyspanne in die 2011 FNB Universiteitsbeker-toernooi. Die FNB Universiteitsbeker het plaasgevind by agt Universiteit kampusse regoor Suid-Afrika. Die FNB Universiteitsbeker rondomtalie het in Februarie 2011 begin waar wedstryde elke Maandagaand, oor ‘n tydperk van sewe tot nege weke, gespeel is. Die uitspeelwedstryde van die top vier spanne het daarop gevolg vir ‘n verdere twee weke. Beide, die voorkoms van beserings en die frekwensies daarvan is aangeteken en vergelyk volgens die oefenprogramme en die hoeveelheid blootstellingsure van die spelers. Beseringsfrekwensies is gerraporteer as die aantal beserings per 1000 uur waar ‘n speler blootgestel word aan die risiko. Beskrywende statistiek is gebruik om die geneighdheid tot, en die voorkoms van alle beserings aan te meld tydens hierdie toernooi. Betekenisvolheidsvlak was geneem op p <0.05. RESULTATE: Sewe van die agt deelnemenede spanne aan die 2011 FNB Varsity Cup was in staat om besering- en oefenstatistiek in te dien. Van hierdie sewe spanne, was daar 178 (6.1 beserings per 1000 ure) beserings in totaal aangemeld regdeur die seisoen. Een en sestig voor-seisoenale beserings is gerapporteerd (2,1 per 1000 ure) in vergelyking met die 117 (4,0 per 1000 ure) inseisoense beserings wat aangemeld is. Daar was 125 wedstrydbeserings (89 per 1000 ure) en 52 beserings tydens oefeninge (1,58 per uur 1000) wat statisties betekenisvol (p = 0,039) was. Die aantal nuwe beserings was baie hoër as die herhalende voorkoms van ‘n besering. Die totale aantal nuwe beserings was 120 (4,1 per 1000 ure) met slegs 52 (2,0 per 1000 ure) herhalendes. Dit was die onderste ledemaat wat in die meerderheid beseringsgevalle (97.5%) geraak is. Oor die hele spektrum was die enkel en die voet die mees beseerde area (15,9%), met die kop (15,3%), skouer (11,4%), dyspier (10,2%), knie (10,2%) en kwadriseps (9,7%) wat soortgelyk geraak is. Areas vir individuelebesering het gewissel tussen voor-en agterspelers. Die voorspelers se mees beseerde anatomiese area was die skouer en enkel (0,5 per 1000 ure). Die dyspier (0,4), enkel-, kop (0,3) en knie (0,2) was die mees beseerde area onder die agterspelers. Die takel was verantwoordelik vir die meerderheid van die beserings (48.1%) onder die voor- en agterspelers. Die mees algemene vorme van beserings was verstuitings en spierverrekking onder die voor- en agterspelers. Die voorspelers het ‘n hoër voorkoms van kontusie en harsingskudding (0,3) in vergelyking met die agterspelers. Die agterlyn dui ‘n algehele hoër tendinopatie (0,2) aan. Onder die voorspelers het die slotte (15,2%) en die stutte (12,9%) die hoogste aantal beserings aangeteken en onder die agterspelers was die vleuels (8,4%) en die senters (9%) die mees beseerde spelers. Die meerderheid van die beserings het plaasgevind gedurende die laaste deel van die eerste helfte (26,7%) en die laaste deel van die tweede helfte (30,7%). GEVOLGTREKKING: Die prevalensie en insidensie van wedstrydbeserings was aansienlik hoër as tydens oefentye. Soortgelyk aan ander beseringsopname studies, was die takel die mees gevaarlike fase van die spel. Die voorspelers wat meer betrokke is in die fisiese kant van die spel het meer beserings in vergelyking met die agterspelers aangeteken 71. Die agterspelers, as gevolg van hul styl van die spel het meer hardloop en versnel beserings aangeteken5,24. Moegheid en 'n gebrek aan fisiese kondisionering kan 'n faktor wees in die meerderheid van hierdie beserings wat gedurende die laaste deel van elke wedstrydshelfte aangeteken word. Verder, die area, tipe en meganisme van beserings wissel oor individuele spelerposisies 24,26. Dit dui daarop aan dat verskillende oefenstyle vir die verskillende posisies aanbeveel moet word as 'n strategie vir besering voorkoming.
41
Mertes, Melanie. "Fluid losses of Division III track athletes experienced during indoor versus outdoor seasons." Online version, 2009. http://www.uwstout.edu/lib/thesis/2009/2009mertesm.pdf.
42
Clokie, Benjamin Gregory James. "Impact of lighting conditions on the developmental physiology of Atlantic salmon (Salmo salar)." Thesis, University of Stirling, 2017. http://hdl.handle.net/1893/27240.
Анотація:
The Atlantic salmon (Salmo salar) lifecycle is punctuated by distinct ontogenic stages which are routinely manipulated commercially by photoperiod regimes to enable year-round production. As such, light plays a critical role throughout the production cycle, however, it remains poorly characterised and light spectrum and intensity have not been defined optimally yet. This thesis was therefore set out to test the effects of narrow bandwidth light (Blue-λ(max) 444 nm, Green-λ(max) 523 nm, Red-λ(max) 632 nm and White) and intensity in freshwater (FW). Fry-parr development, out-of-season smoltification and ocular and vertebral health were examined as was the long-term effects of FW light regimes on seawater (SW) growth and muscle structure. In addition, the impact of photoperiod regimes on out-of-season smolts following transfer to SW was investigated.
Major findings from the trials conducted show that light spectrum and intensity influence parr development with lower intensities performing better than higher intensities. Both the initiation and duration of smoltification was impacted by spectrum. Importantly, this doctoral work showed that daily changes in light intensity, from low during the scotophase to high during the photophase applied for the duration of a standard out-of-season smoltification regime was capable of providing a sufficient cue for the induction of smoltification. Historic FW light exposure impacted SW performance and post-transfer SW photoperiod had significant impact upon growth and maturation development. Results based on changes to the gonadosomatic index provide important guidance for suitable post-transfer photoperiods for smolt transferred to SW around the winter solstice. Importantly, from the parameters tested, exposure to different spectrum or light intensities did not adversely affect vertebral or ocular health.
This thesis did not only focus on the physiological effects of light but also aimed to characterise better the pathways involved in light perception and integration. To do so, the neural response to both broad spectrum white light, darkness and Red and Blue light was investigated through deep brain insitu-hybridisation and high throughput sequencing (NGS) of the pituitary gland. Results showed substantial spectral and light/dark changes in the both the deep brain and pituitary transcriptome. Overall, this research provides both scientifically interesting and commercially relevant guidance for the optimisation of lighting systems for use in captive salmon aquaculture. Major findings from the trials conducted show that light spectrum and intensity influence parr development with lower intensities performing better than higher intensities. Both the initiation and duration of smoltification was impacted by spectrum. Importantly, this doctoral work showed that daily changes in light intensity, from low during the scotophase to high during the photophase applied for the duration of a standard out-of-season smoltification regime was capable of providing a sufficient cue for the induction of smoltification. Historic FW light exposure impacted SW performance and post-transfer SW photoperiod had significant impact upon growth and maturation development. Results based on changes to the gonadosomatic index provide important guidance for suitable post-transfer photoperiods for smolt transferred to SW around the winter solstice. Importantly, from the parameters tested, exposure to different spectrum or light intensities did not adversely affect vertebral or ocular health. This thesis did not only focus on the physiological effects of light but also aimed to characterise better the pathways involved in light perception and integration. To do so, the neural response to both broad spectrum white light, darkness and Red and Blue light was investigated through deep brain insitu-hybridisation and high throughput sequencing (NGS) of the pituitary gland. Results showed substantial spectral and light/ dark changes in the both the deep brain and pituitary transcriptome. Overall, this research provides both scientifically interesting and commercially relevant guidance for the optimisation of lighting systems for use in captive salmon aquaculture.
43
Brown, P. W., and J. C. Silvertooth. "Boll Maturity Estimates for Mid- and Late-Season Flowering Dates in Arizona." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/209599.
Анотація:
Boll maturity dates and the number of days after flowering for a boll to reach physiological maturity were estimated for six representative flower dates: 15 July, 29 July, 12 August, 26 August, 9 September and 23 September. Estimates were developed for 28 locations using historical heat unit (HU) information using the assumption that 600 HUs are required after flowering for a boll to reach physiological maturity. The results are presented in both tabular and graphical forms.
44
Gentles, Jeremy A., Christine L. Coniglio, Matthew M. Besemer, Joshua M. Morgan, and Michael T. Mahnken. "The Demands of a Women's College Soccer Season." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etsu-works/3974.
45
groezinger, erich yager. "Relationship between pre-season measures of fitness and power to in game measures for a Division 1 collegiate ice hockey team." Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1468855444.
46
Pessarakli, Mohammed, David M. Kopec, and Jeff J. Gilbert. "Growth Responses of Selected Warm-Season Turfgrasses under Salt Stress." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2009. http://hdl.handle.net/10150/216660.
Анотація:
Use of low quality/saline water for turf irrigation, especially in regions experiencing water shortage is increasing. This imposes more salt stress on turfgrasses which are already under stress in these regions. Therefore, there is a great need for salt tolerant turfgrasses to survive under such stressful conditions. This study was conducted in a greenhouse, using hydroponics system, to compare growth responses of three warmseason turfgrasses, bermudagrass (Cynodon dactylon L.), cv. Tifway 419, seashore paspalum (Paspalum vaginatum Swartz), cv. Sea Isle 2000, and saltgrass (Distichlis spicata L), accession A55 in terms of shoot and root lengths and DM, and canopy green color (CGC) under salt stress condition. Whole plants, stolons, and rhizomes were grown in Hoagland solution for 4 months prior to initiation of salt stress. Then, plants were grown for 12 weeks under 4 treatments (control, 7000, 14000, and 21000 mg/L NaCl) with 4 replications in a RCB design trial. During the stress period, shoots were clipped bi-weekly for DM production, shoot and root lengths were measured, and CGC was evaluated weekly. The bi-weekly clippings and the roots at the last harvest were oven dried at 60o C and DM weights were recorded. Shoot and root lengths and shoot DM weights decreased linearly with increased salinity for bermudagrass and paspalum. However, for saltgrass these values increased at all NaCl levels compared with the control. For bermudagrass and paspalum, the highest values were obtained when the whole plants were used, and the lowest ones resulted when the rhizomes were used. The reverse was found for saltgrass. For the control plants, the measured factors were higher and the canopy colors were greener for bermudagrass and paspalum compared with saltgrass. The canopy color changed to lighter green for bermudagrass and paspalum as NaCl salinity increased, but saltgrass maintained the same color regardless of the level of salinity.
47
Pessarakli, Mohammed, and David M. Kopec. "Comparing Growth Responses of Selected Cool-Season Turfgrasses under Salinity and Drought Stresses." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2009. http://hdl.handle.net/10150/216642.
Анотація:
This study was conducted in a greenhouse, using hydroponics system, to compare growth responses of three cool-season turfgrass species, Creeping bentgrass (Agrostis stolonifera), Rough bluegrass (Poa trivialis), and Perennial ryegrass (Lolium sperenne) in terms of shoot and root lengths and dry matter (DM), and percent canopy green cover (%CGC) under salinity and drought stresses. Grasses were grown in Hoagland solution for 90 days prior to initiation of salinity or drought stresses. Then, 24 meq NaCl/L culture solution/day were added for each -0.1 MPa OP of salinity stress, or 75 and 119 g of PEG/L were added for -0.2 and -0.4 MPa OP of drought stress treatments, respectively. The treatments included control, -0.2 and -0.4 MPa OP salinity, -0.2 and -0.4 MPa OP drought stress. Four replications of each treatment were used in a RCB design experiment. During the stress period, grass shoots were clipped weekly for DM production, shoot and root lengths were measured, and %CGC was evaluated. The weekly clippings and the roots at the last harvest were oven dried at 60° C and DM weights were recorded. All 3 grass species were more severely affected by drought than salinity. Bluegrass was the most and bentgrass the least severely affected by either drought or salinity stress.
48
Mahoney, Jessica. "The Applicability of Physiology for Conservation and Management Purposes: A Case-Study Using the Breeding Season of the Red-winged Blackbird (Agelaius Phoeniceus)." Diss., North Dakota State University, 2017. https://hdl.handle.net/10365/26502.
Анотація:
Physiology has the potential to play a unique and important role in conservation and management practices by helping identify the mechanistic responses of populations to environmental changes, and providing physiological tools and knowledge that can be applied to help solve conservation and environmental problems. It has previously been unclear, however, if the increase of physiology in conservation and management literature has translated into the application of physiological tools and knowledge into conservation and management plans. There were two purposes of this disquisition: 1) analyze how physiological tools have been integrated into applied conservation by reviewing USFWS endangered species recovery plans, and provide suggestions to help conservation scientists and physiologists work synergistically to solve conservation and management problems, and; 2) provide an example of how studying the physiology of a species can provide useful information for making management decisions, using the study of stress physiology in the red-winged blackbird (Agelaius phoeniceus) during their breeding season as our case study. Our results suggest that physiology is being underutilized in USFWS endangered species recovery plans. We hypothesize this absence of physiological tools and knowledge in conservation planning is primarily due to a deficit of physiological knowledge passing between physiologists and the cohort of federal agency recovery plan writers. We suggest the need for increased training of federal agency employees, the inclusion of authors with academic affiliations, increased integration of physiology and conservation research, and enhanced communication between all concerned parties. To illustrate how physiology can be useful, we exposed female red-winged blackbirds to predator and nest parasitism effigies, thus causing additional stress, during the breeding season. We were able to examine how females respond behaviorally and physiologically to stress, and how these responses alter their reproductive decisions. We found that females are responding both behaviorally and physiologically to the increased threat of predation and nest parasitism. There is potential to exploit these responses to manage the species, such as causing females to forgo breeding. We also determined that an individual?s stress physiology can be changed when held in captivity. We suggest using caution when trying to extrapolate captive data to wild populations.This disquisition research was financially supported by North Dakota State University, and a cooperative agreement with the United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Service ? National Wildlife Research Center, under the direction of the Study Directors, Dr. Page E. Klug, and Dr. George M. Linz (WS-NWRC QA-2116).
49
Olson, Jordan T. "Changes in bone mineral density of collegiate middle distance and long distance runners across an indoor season." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1469096419.
50
MacDonald, Christopher, Ryan Alexander, Adam Sayers, Howard Gray, Michael Israetel, Aaron Casey, Jeremy A. Gentles, et al. "Changes in Measures of Power in NCAA Division I Female Soccer Athletes Through Competitive Seasons." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etsu-works/3984.