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Water stress and remobilization of dry matter and nitrogen in wheat and barley genotypesSarvestani, Zeinolabedin Tahmasebi. January 1996 (has links) (PDF)
Bibliography: leaves 223-247. Effects of water availability during grain filling is examined in wheat (Triticum aestivum L.) and barley (Hordum vulgare L.) genotypes. The study tests the accumulation of dry matter (DM) and nitrogen (N) in the grain and also their remobilization from the shoot to the grain. Water stress during grain filling was found to reduce DM and N accumulation and also to increase N concentration in both wheat and barley grain.
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Stress induced differential gene expression in the brain of juvenile steelhead trout, (Oncorhynchus Mykiss)Schwindt, Adam R. 03 December 2002 (has links)
Gene expression profiles of tissues and cell-lines can be powerful tools for
documenting the genetic response to a particular treatment, such as stressors.
However, there is a paucity of information on the genetic stress response in the
brain. Therefore, we attempted to profile gene expression in the brain of juvenile
steelhead trout (Oncorhynchus mykiss) in response to stressors commonly
encountered in aquaculture settings and similar to those encountered in hydropower
dam mitigation efforts.
We subjected fish to a combined out-of-water and low-water stressor
totaling three hours. Plasma stress response factors indicate that fish were
undergoing a physiological stress response after 3 hours of continuous stressor. We
utilized suppression subtractive hybridization to identify cDNA fragments up- or
down-regulated in the brain upon completion of the stressor. Forward and reverse
subtractions, and sub-cloning of the purified PCR products yielded 59 clones all of
which were sequenced. Sequenced cDNA fragments were subjected to BLASTn
and BLASTx searches over the course of one year. Fragments fell into the
following functional categories: those associated with ATP generation, signal
transduction, ion transport, translational machinery, DNA packaging and
mobilization, cell structure, and cDNA fragments with cryptic function. Of the 59,
12 were selected for further analysis, and 5 were confirmed to be differentially
expressed by northern hybridization. The differentially expressed genes included
cytochrome b, NADH dehydrogenase subunit 2, ATPsynthase subunit 6, a cDNA
fragment with unknown function, and neuron specific gene 1.
Our results present a first attempt to profile gene expression in the brain of
fish and demonstrate the power of molecular tools at capturing large amounts of
biological information without having to target any one particular gene. A gene
expression profile of the brain consequent to stress provides a catalog of responses
at a given time point. This catalog can then be used to isolate full-length cDNAs,
localize mRNAs in the brain or other tissue, as probes to determine expression
patterns and time courses of gene expression in other tissues, and for the
quantification of cDNA molecules with real time PCR. / Graduation date: 2003
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Immediate effects of acute stress on innate immunity in rainbow trout (Oncorhynchus mykiss)Demers, Nora Egan 11 June 1996 (has links)
This thesis tests the hypothesis that innate immunity may be enhanced
immediately following a stressful event. The experiments characterize the acute
effects of the fight or flight response on some immunological and endocrine
parameters in rainbow trout (Oncorhynchus mykiss). Plasma cortisol and
catecholamines were elevated within seconds of the initiation of an acute
handling stressor consisting of 30 seconds in the air and five, 10 or 20 minutes in
a shallow bucket of water. Plasma lysozyme activity increased after stress,
however, the increases were not statistically significant unless variation was
reduced by serial bleeding of the same individual trout before and after stress. A
more "resting" fish was achieved by use of the anesthetic 2-phenoxy-ethanol
which was surreptitiously introduced into the tanks before the initial bleed.
Individual fish were then revived in freshwater and stressed as before.
Enhancement of lysozyme activity was evident although levels of plasma stress
hormones in fish that were anesthetized, revived and stressed were less than
when fish were similarly stressed without anesthetic. Levels of cortisol and
catecholamines increased within seconds of capture and aerial exposure,
returned to near pre-stress levels after the fish had been placed in a shallow
bucket of water for 30 seconds, then increased again. Evaluation of the influence
of acute stress on survival following challenge with the pathogen Vibrio
anguillarum yielded equivocal data. Results presented here suggest that
enhancement of innate defenses as part of the fight or flight response merits
further evaluation. / Graduation date: 1997
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Water stress and remobilization of dry matter and nitrogen in wheat and barley genotypes / by Zeinolabedin Tahmasebi Sarvestani.Sarvestani, Zeinolabedin Tahmasebi January 1995 (has links)
Bibliography: leaves 223-247. / xiii, 247 p. : ill, maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Effects of water availability during grain filling is examined in wheat (Triticum aestivum L.) and barley (Hordum vulgare L.) genotypes. The study tests the accumulation of dry matter (DM) and nitrogen (N) in the grain and also their remobilization from the shoot to the grain. Water stress during grain filling was found to reduce DM and N accumulation and also to increase N concentration in both wheat and barley grain. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1996
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Die ontwerp en toepassing van 'n sielkundige inligtingsprogram vir die beroerte-pasiënt se eggenoot/eggenoteJoubert, Wickus G. 28 August 2012 (has links)
M.A. / The purpose of this research was to compile a psychological information program on stroke, and to provide this psychological information to the spouse of the stroke patient.The emotional status of the spouse of the stroke patient was evaluated during the intervention.The final goal of this research was to give a phenomenological description of the experiences of the spouse of the stroke patient. The method for collecting data was 1) to evaluate the emotional status of the spouse of the stroke patient with the POMS (Profile Of Mood State) inventory before he was exposed to the content of the psychological information program on stroke.2) The spouse of the stroke patient was then introduced to the psychological information program, and any questions which arose were answered. 3) A follow up appointment was arranged for ten days later. During this appointment the POMS inventory was administered again to assess the spouse's emotional status after exposure to the psychological informationprogram on stroke.Any further questions were answered.Within a framework of identified themes a phenomenological description of the experiences of the spouse of the stroke patient was given.The most important experiences were identified as confusion, anxiety, tension, rage, frustration, tiredness, and feelings of not being motivated and depression.The phenomenological themes were "Om-te-wees (Dasein)", "Die wereld", "In-die-wereld-wees", "Om-ingegooi-tewees- in-die-wereld", "Angs as basiese ingesteldheid tot die wereld" and "Liggaamlikheid". The current research was motivated after a thorough study of the literature on stroke.The literature survey revealed a deficiency in terms of availability of information on stroke to the spouse of the stroke patient after the stroke has occured.The literature survey disclosed that the focus of research has been on the stroke patient.Research identified the spouse of the stroke patient as the primary caretaker.Therefore it is important that the spouse of the stroke patient will have access to psychological information on stroke to assist them during their tasks of caretaking. Certain variables influenced theresults of the present research project.These variables were 1) the time when the psychological information was provided to the subjects, 2) the emotional status after the stroke had occurred, and 3) the extent of information the subjects received from other resources. During the current research project the subjects confirmed the value of the availability of psychological information on stroke.The psychological information on stroke is important in assisting the spouse of the stroke patient during their tasks of caret•king.The psychological information on stroke provides the spouse of the stroke patient with 1) a better understanding of the stroke patient, 2) knowledge of what to expect after a stroke had occured, and 3) realistic goals for the future.
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Physiological response of tigerfish and smallmouth yellowfish to angling: impact of angling duration, fish size, fish age, sexual maturity, body condition and temperatureGerber, Ruan Jan-Izak Lodewyk 16 May 2011 (has links)
M.Sc. / The practice of catch-and-release (C&R) fishing has been widely promoted as a conservation strategy and fisheries management tool and is currently considered an ecologically sustainable practice. Factors negatively affecting fish as well as mortality have, however been shown to occur. The overall aims of this study were to determine the effect of C&R angling on tigerfish Hydrocynus vittatus and Vaal-Orange smallmouth yellowfish Labeobarbus aeneus by studying the physiological stress response as well as age, growth and reproductive characteristics. To determine the physiological response of tigerfish (n=63) and smallmouth yellowfish (n=96) data were collected during August/September 2008 (Okavango Delta) and from June 2008 through to December 2008 (Vaal River) for the respective species. Fish were collected using standard angling and fly-fishing techniques, anaesthetised in clove oil and blood drawn from the caudal veins; thereafter fish were weighed and measured, revived and released. To serve as controls, randomly selected fish (from each species) were kept for 72 h in pools filled with river water. Blood plasma was analysed for concentrations of glucose, cortisol and lactate to determine the effects of angling duration, fish size, and water temperature. In both species larger fish were shown to be angled for a longer duration compared to smaller fish. Levels of glucose, at times, were affected by water temperature (influenced by time of year). Plasma glucose concentrations in H. vittatus showed a slight increase whereas levels in L. aeneus decreased with greater angling durations. Few individuals from each species, (n=13 for H. vittatus and n=12 L. aeneus) showed significantly increased plasma cortisol concentrations. Lactate concentrations were found to increase significantly above control values in H. vittatus angled for < 1 min and L. aeneus angled for > 1 min. Increased handling durations of captured H. vittatus that had been angled for < 1 min showed a significant increase in plasma lactate concentrations. Results from the control fish indicated that baseline levels of lactate in H. vittatus and cortisol and lactate in L. aeneus were restored within 72 h of capture. The relative age of the selected species were determined with the aid of scales, lapillus otoliths (H. vittatus) and asteriscus otoliths (L. aeneus) The most appropriate methods found for ageing the two species were sectioned lapillus otoliths for H vittatus and whole asteriscus otoliths for L. aeneus. Males and females from both species were found throughout the age classes. Male and female H. vittatus had a longevity of 20 years and 16 years respectively, similarly, male and female L. aeneus had longevities of 19 years and 15 years respectively (relative age for both species). Summary 11 Hydrocynus vittatus males matured at a total length (TL) of 451mm and females matured at 522mm TL, corresponding to an approximate relative age of 4 years for both sexes. Labeobarbus aeneus males matured at a fork length (FL) of 289mm and females matured at 367mm FL, corresponding to relative ages of 4 and 6 years respectively. This is the first study of its type reporting on the physiological response of African freshwater game fish species as well as the first report of age determination of H vittatus in the Okavango Delta and the first for this species using otoliths. While the age of various L. aeneus populations have been studied this is the first time that otoliths are used in the Vaal River population. This study confirms that the physiological response, and potential negative effects of C&R are species specific, and that studies should be done on all targeted freshwater game fish species to ascertain the physiological stress imposed by C&R angling.
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Recovery from stress during exposure to videotaped outdoor environments.Parsons, Russ John. January 1991 (has links)
There is a long history of visual preferences for natural environments over urban environments, as well as beliefs in the restorative value of time spent in natural environments. Diverse theoretical perspectives, such as information overload, learning and evolutionary theories, can be used to help explain these preferences and beliefs, and early empirical research has found tentative support for them. The present study capitalizes on a recovery-from-stress experimental paradigm developed by Ulrich. Subjects are presented with a brief videotaped stressor followed by a brief videotaped outdoor environment while psychological and physiological indicators of arousal and emotion are monitored. In this study, two stressors and four environments were manipulated between subjects. The environments differed along two dimensions that were derived from visual preference research and theoretical predictions: whether they were natural or urban in character, and the presence or absence of a river. Physiological indicators of arousal included heart rate, skin conductance, respiration rate and salivary cortisol levels. Facial electromyographic (EMG) placements were used to assess the emotional valence of subjects' responding. The Zuckerman Inventory of Personal Responses (ZIPERS) was used to assess psychological responding. Analyses yielded a limited and occasionally inconsistent pattern of results. Many of the inconsistent responses to the environments were found across stressors, suggesting that either arousal level or the particular nature of the arousal generated by the two stressors may have interacted with the recovery environments. Despite these inconsistencies, the tentative conclusions that could be reached were generally consistent with past research and theoretical predictions. Evidence from the arousal variables suggested that the Nature and Water environments elicited less arousal during the recovery phase than did the Urban and Non-Water environments; and, there was corraboration or partial corraboration for each of these findings from the self-report data. Similarly, data from the EMG placements favored the Nature environments over the Urban environments, and in particular suggested that the Non-Water Natural (meadow) environment was less likely to produce negative emotions than the other environments. Again, this finding received some support from the self-report data. Possible explanations for the limited and occasionally inconsistent nature of the findings are offered in the discussion section, with the most likely candidate being the relatively attractive Urban environments used in this study compared to those used in past research.
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Phytate and plant stress responsesLe Fevre, Ruth Elizabeth January 2014 (has links)
No description available.
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Mitogen activated protein kinase cascades mediate the regulation of antioxidant enzymes under abiotic stresses in arabidopsisXing, Yu 01 January 2007 (has links)
No description available.
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Environmental stress and calcium nutrition during the seed-filling stage of soybeanSorooshzadeh, Ali. January 1997 (has links)
No description available.
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