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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Factors Influencing the Ecology of Greater Sage-Grouse Inhabiting the Bear Lake Plateau and Valley, Idaho and Utah

Cardinal, Casey J. 01 May 2015 (has links)
Greater sage-grouse (Centrocercus urophasianus; sage-grouse) are a sagebrush obligate species and as such an indicator of sagebrush (Artemisia spp.) habitat quality and quantity. Sage-grouse populations have declined across western North America. This decline has been attributed to habitat loss and degradation of the sagebrush ecosystem. To determine factors that may cause localized declines in sage-grouse populations, managers may need site-specific information on the ecology and habitat use patterns of meta-populations. This information is currently lacking for sage-grouse populations that inhabit the Bear Lake Plateau and Valley (BLPV), encompassing parts of Idaho, Utah and Wyoming. I captured, radio-marked and monitored 153 sage-grouse in the BLPV from 2010–2012 to assess nest success, brood survival, mortality factors, and habitat use. Reproductive success was lower than range-wide averages, with especially low success in 2011. Nesting and brood rearing both showed higher success rates in 2012. Survival was very similar to estimates found elsewhere. Females had higher survival rates than males, and yearlings had higher survival probability than adults. Sage-grouse mortality was highest in summer and spring, and lowest in fall. Individual sage-grouse completed large scale movements, often using habitats in Idaho, Utah, and Wyoming. Important factors in sage-grouse habitat selection included distance to major road, distance to habitat edge, distance to vertical structure (i.e., communication towers, wind turbines, and transmission lines), and vegetation cover types. Sage-grouse tended to avoid major road and vertical structures (i.e., communication towers, wind turbines, and transmission lines). They also selected habitat further away from habitat edge. Vegetation types preferred by sage-grouse included shrubland habitats, wet meadows, and grassland. MaxEnt models did not place highest importance on sagebrush habitats, which are critical for sage-grouse presence. This could have occurred because the vegetation layers used in the model did not assess habitat quality. Models produced using the ten landscape variables and BLPV sage-grouse locations ranked good to excellent fits. State-defined habitat covered a larger extent than MaxEnt predicted habitat. MaxEnt predicted habitat areas may be used to further refine state identified core areas to assist in prioritization of conservation efforts to protect the BLPV sage-grouse population.
142

Effect of Predator Removal on Greater Sage-Grouse (Centrocercus urophasianus) Ecology in the Bighorn Basin Conservation Area of Wyoming

Orning, Elizabeth Kari 01 December 2013 (has links)
The decline of greater sage-grouse (Centrocercus urophasianus) populations across western North America has intensified conservation, research, and management efforts. Predator-prey interactions have been the focus of widespread scientific study, but little research has been conducted on the effects of predation and predator removal on sage-grouse ecology. This study had three main objectives: 1) identify the types of predators impacting hen survival and nest success, 2) compare the effect of predator removal on vital rates, and 3) evaluate habitat selection and movement. Over two years (2011-2012), an observational study and field experiment were used to test the effects of predation and predator removal on sage-grouse survival, nest success, and spatial ecology in Bighorn Basin, Wyoming. In year one, I quantified the impacts of predators on sage-grouse demographics and developed a basis for monitoring sage-grouse and predator populations. In year two, predator removal was modified to remove the primary nest and hen predator in this system: coyote (Canis latrans). I evaluated the impact of anthropogenic features and management on sage-grouse home range size, seasonal movement, and habitat selection for potential behavioral responses. Resource selection functions (RSFs) were used to determine habitat selection and identify differences at multiple spatial extents (seasonal and annual scales). Hen survival was improved in sites treated with coyote removal over the nesting period (P = 0.05) but no improvement was seen in annual hen survival (P = 0.19). Observed nest success was higher at the site without coyote removal (P < 0.0001). RSF modeling showed sage-grouse to be sensitive to predator removal, avoiding areas close to roads, with high well density, and steep slopes. While this study suggests predator removal does not benefit observed nest success, provides only short-term enhancement to survival, and may disrupt habitat selection, potentially benefits to other life stages could exist and be detected with more time and monitoring. By taking an experimental approach to examining the effects of predation and predator removal, this study advances our knowledge of sage-grouse ecology by identifying changes in demographic vital rates and habitat selection, propagating the best management possible for sage-grouse populations.
143

Greater Sage-Grouse Ecology, Chick Survival, and Population Dynamics, Parker Mountain, Utah

Dahlgren, David K. 01 May 2009 (has links)
We estimated survival of ~ 1-day-old chicks to 42 days based on radio-marked individuals for the Parker Mountain greater sage-grouse (Centrocercus urophasianus) population. Chick survival was relatively high (low estimate of 0.41 and high estimate of 0.50) compared to other studies. Brood-mixing occurred for 21 % of radio-marked chicks, and within 43 % of radio-marked broods. Our study showed that brood-mixing may be an important ecological strategy for sage-grouse, because chicks that brood-mixed experienced higher survival. Additionally, modeling of chick survival suggested that arthropod abundance is important during the early brood-rearing period (1 - 21 days). We also used life-cycle modeling (perturbation analyses and Life Table Response Experiments) to assess the importance of various vital rates within this population. We determined that adult hen survival and production (chick and fledgling survival) had the most influence on growth rate. Moreover, we assessed various methods (walking, spotlight, and pointing dog) for counting sage-grouse broods. Spotlight and pointing dog methods were more effective than walking flush counts, and the latter may underestimate chick survival.
144

Des Caractères de La Bruyère au Gil Blas de Lesage : de la réflexion morale à la mise en oeuvre romanesque.

Saheb-Alouche, Lucie January 1971 (has links)
No description available.
145

Effect of light level on the growth and essential oil production of two herbs :: sage (Salvia officinalis) and thyme (Thymus vulgaris) /

Li, Yan-li 01 January 1996 (has links) (PDF)
No description available.
146

The ecology of translocated greater sage-grouse in Strawberry Valley, Utah

Baxter, Rick Joseph 20 November 2007 (has links) (PDF)
Manuscript No. 1 Translocations of greater sage-grouse (Centrocercus urophasianus) have been attempted in 7 states and one Canadian province with very little success. To recover a small remnant population and test the efficacy of sage-grouse translocations, we captured and transported 137 adult female sage-grouse from 2 source populations to a release site in Strawberry Valley, Utah during March-April 2003-2005. The resident population of sage-grouse in Strawberry Valley was approximately 150 breeding birds prior to the release. We radiomarked each female and documented survival, movements, reproductive effort, flocking with resident grouse, and lek attendance. We used Program MARK to calculate annual survival of translocated females in the first year after release, which averaged 0.60 (95% CI = 0.515-0.681). Movements of translocated females were within current and historic sage-grouse habitat in Strawberry Valley, and we detected no grouse outside of the study area. Nesting propensity for first (newly translocated) and second (surviving) year females was 39% and 73%, respectively. Observed nest success of all translocated females during the study was 67%. By the end of their first year in Strawberry Valley, 100% of the living translocated sage-grouse were in flocks with resident sage-grouse. The translocated grouse attended the same lek as the birds with which they were grouped. In 2006, the peak male count for the only remaining active lek in Strawberry Valley was almost 4 times (135 M) the 6-year pretranslocation (1998 − 2003) average peak attendance of 36 males (range 24 – 50 M). Translocations can be an effective management tool to increase small populations of greater sage-grouse when conducted during the breeding season and before target populations have been extirpated. Manuscript No. 2 Nesting habitat of resident greater sage-grouse in extant populations across the species range has been thoroughly described in the literature, yet very little is known about the use of nesting habitat by translocated sage-grouse. In order to better understand nesting habitat selection by translocated sage-grouse in a new environment, we trapped grouse during the spring on and near leks of source populations. We placed each female in a cardboard box and translocated them overnight to the Strawberry Valley. Each female was fitted with a radio-transmitter and released near the lek where males were actively strutting. We monitored grouse for nesting activity. We documented nesting attempts, nest success, clutch size and embryo viability. We recorded data on habitat variables associated with nest sites and paired-random sites. We used logistic regression and an a priori information theoretic approach for modeling nest versus paired-random sites and successful versus unsuccessful nest sites. Our data suggested that crown area of the nest shrub and percent grass cover were the two variables that discriminated between nest and paired-random sites. Females that nested successfully selected sites with more total shrub canopy cover, intermediate size shrub crown area, a normal distribution of aspects, and with steeper slopes than unsuccessful nests. Translocated females selected suitable nesting habitat after being moved from source populations with differing habitats. Manuscript No. 3 Equivalence testing in the field of wildlife ecology has been underutilized. Mistakenly, many researchers have concluded that two groups are the same based on failure to reject a null hypothesis of no difference. We used equivalence testing to provide preliminary evidence that resident and translocated bird movements were similar. Translocations are becoming more prominent in the field of conservation biology as a wildlife management tool. We translocated greater sage grouse into a fragmented habitat in order to conserve the metapopulation. We placed radio-transmitters on resident and translocated female greater sage grouse and used the distance moved from the release site or lek as a measure of translocation success and/or site fidelity. If translocated birds did not show site fidelity, the translocations would be judged a failure. The distributions of resident and translocated sage grouse movements for both summer and winter seasons were significantly different, primarily due to differences in the proportions of specific habitat fragments used. Equivalence tests showed that site fidelity was statistically equivalent for translocated and resident grouse,when defined as a difference of ≤3 km, both in summer and winter. In particular, translocated females traveled no farther from the release site than resident females. Equivalence testing was the statistical tool used to determine equivalence of resident and translocated sage grouse movements and thus judge preliminary translocation success.
147

Analyses of Greater Sage-Grouse (Centrocercus urophasianus) Translocation Release Methods and Chick Survival in Strawberry Valley, Utah

Hennefer, Jordan P. 19 March 2007 (has links) (PDF)
Manuscript No. 1 Recent research has indicated that low nest success and juvenile survival of Greater Sage-Grouse may be responsible for population declines. Recent technological advances in micro-transmitters have made radio-telemetry studies on Sage-Grouse chicks more common. Radio-telemetry enables monitoring of individual chicks and broods during a critical period of their life history. The exact cause of low chick recruitment in Strawberry Valley has not been well understood. In 2006, a chick mortality study using micro-transmitters was initiated to (1) determine the causes of chick mortality, (2) calculate overall chick survival, (3) compare chick survival in the Strawberry Valley population to published reports, (4) monitor brood movements, and (5) suggest management strategies for mitigation of chick mortality. Survival data on radio-marked chicks were analyzed using a known fate model in program MARK. Chick survival in Strawberry Valley was greater than all reported estimates from other studies. Our study did not identify any unsuspected causes of chick mortality, and the cumulative effect of stressing chicks, hens, and broods was not deemed worth the benefit, especially in a population recovery setting like Strawberry Valley. We do not recommend the use of radio-telemetry on Sage-Grouse chicks in recovering or sensitive populations. Manuscript No. 2 In 2003, we began translocating Greater Sage-Grouse into the Strawberry Valley of central Utah, in an attempt to recover the dwindling population found therein. Prior to 2006 all translocated Sage-Grouse were released within 250 m of the only active lek in Strawberry Valley while males were actively strutting. A prolonged winter in 2006 delayed normal lekking activity in Strawberry Valley. As a result 61 (59%) of the 103 sage-grouse translocated in 2006 were not released near an active lek. We analyzed the influence that release timing, hen age, body mass, and source population had on mortality, flocking, and dispersal distance of translocated hens in 2006. We found that mortality and flocking rates were not influenced by release timing, hen age, body mass, or source population. Dispersal distances for hens released near a lek with actively strutting males were significantly less than distances of hens released near an inactive lek. We believe that releasing translocated Sage-Grouse near a lek with actively strutting males is an essential technique for Greater Sage-Grouse translocations. We recommend that other Sage-Grouse translocation efforts employ this method to increase the likelihood of success.
148

Är zuranolon en säker och effektiv behandling vid förlossningsdepression? : En litteraturstudie / Is Zuranolone a safe and effective treatment of postpartum depression? : A literature review

Olsson, Ellinor January 2024 (has links)
Postpartum depression is a condition that displays symptoms such as insomnia, anxiety, and difficulties with feeling happiness. This affects approximately 10–17 % of pregnant women and new mothers around the world. The hypothalamic-pituitary-adrenal axis (HPA-axis) and the downregulation of gamma-aminobutyric acid (GABA) signaling are believed to be a part of the pathology behind postpartum depression, although it is currently not known in detail what causes the condition to develop. Women with postpartum depression are believed to have a hyperactive HPA-axis due to an increased sensitivity to estrogen and progesterone. If postpartum depression is left untreated, there could be severe consequences. For example, women who have had postpartum depression have a three times higher risk of death than those who have not encountered the condition. There could also be consequences for the newborn since there is for instance a risk of impaired cognitive ability among children whose mother has had postpartum depression. Psychological treatment consists of cognitive behavior therapy and interpersonal therapy among others. Today there is no approved medication in Sweden for the indication postpartum depression but there is two in the US, brexanolone and zuranolone. Brexanolone is administered by intravenous infusion, which limits the patient to hospital treatment. Zuranolone is a synthetic molecule that is designed to imitate the neurosteroid allopregnanolone as an agonist for the GABAa-receptor. It is the first medication for the indication that is administered orally. The mechanism of action is not fully elucidated but zuranolone binds to GABAa-receptors, upregulates the expression of GABA-receptors and increases GABA-signaling.  The purpose of this literature study was to evaluate the safety and efficacy of zuranolone for the treatment of postpartum depression. Five relevant clinical studies were collected from the database PubMed. The results show a statistically significant difference compared to placebo that zuranolone seems to be effective for postpartum depression using several self-assessment scales, e.g. the Hamilton Rating Scale for Depression (HRSD-17), the Hamilton Rating Scale for Anxiety (HRSA) and the Montgomery-Åsberg Depression Rating Scale (MADRS). Zuranolone was also shown to be effective in treatment of insomnia as shown by an increase of objective sleep efficacy. The most common side effect was somnolence and beside that there were not many severe side effects throughout the studies. Since self-assessment scales were used, the results can vary due to how different people proceed their emotions and thoughts. Even though it is currently unknown if zuranolone is safe for breastfeeding women, the medication gives mothers a chance to feel better without having to undergo hospital treatment, which is the case with brexanolone. More studies are needed, for instance to investigate if zuranolone is safe to use for adolescents or breastfeeding women. It is also necessary to do a follow-up on how the treated patients´ mental health displays months, or years, after treatment. / Förlossningsdepression är ett tillstånd som ger symtom som sömnsvårigheter, ångest och att känna sig nedstämd. Detta beräknas drabba ca 10–17% av alla gravida eller nyblivna mammor världen över. Det är inte helt klarlagt vad tillståndet beror på men det tros ha en koppling till bl.a. hypotalamus-hypofysbinjure-axeln (HPA-axeln) och en nedreglering av gamma-amino-smörsyra(GABA)-signalering. HPAaxeln tros vara överaktiv på grund av ökad känslighet för hormonerna östrogen och progesteron hos patienter med förlossningsdepression. Sjukdomen kan ge negativa effekter för både kvinnan och barnet, till exempel ses en tre gånger högre dödsrisk hos mammor som haft förlossningsdepression och en risk för nedsatt kognitiv förmåga hos barnet vars mamma haft förlossningsdepression. Förlossningsdepression kan ibland behandlas psykologiskt med exempelvis kognitiv beteendeterapi (KBT) eller interpersonell terapi (IPT) men ibland också med läkemedel. I Sverige finns ännu inget godkänt läkemedel med indikationen men i USA finns det två, brexanolon samt zuranolon. Brexanolon ges som intravenös infusion vilket begränsar patienten till sjukhusinläggning. Zuranolon är en syntetisk molekyl som efterliknar neurosteroiden allopregnanolon och är det första läkemedlet med indikationen förlossningsdepression som ges peroralt. Dess verkningsmekanism är delvis okänd men zuranolon binder in till GABAa-receptorer och uppreglerar uttrycket av GABA-receptorer samt ökar GABAsignalering.   Syftet med denna litteraturstudie var att undersöka om zuranolon är en säker och effektiv behandling vid förlossningsdepression. Detta gjordes genom en artikelsökning via databasen PubMed där fem relevanta kliniska studier valdes ut. Studierna visade att zuranolon är en effektiv behandling då preparatet visade en statistiskt signifikant skillnad jämfört med placebo på flera självskattningsskalor, som Hamilton Rating Scale for Depression (HRSD-17), Hamilton Rating Scale for Anxiety (HRSA) och MontgomeryÅsberg Depression Rating Scale (MADRS). Zuranolon visade sig också vara effektiv vid behandling av sömnsvårigheter då objektiv sömneffektivitet ökade. Den vanligaste biverkningen var trötthet och det förekom inte många allvarliga biverkningar. Eftersom resultaten främst mättes med självskattningsskalor kan variation uppstå då olika individer tolkar och känner känslor och tankar på olika sätt. Även om det ännu är oklart om zuranolon är säkert för ammande kvinnor och deras nyfödda barn, ger läkemedlet möjligheten för nyblivna mammor att må bättre utan att behöva behandlas på sjukhus, till skillnad från brexanolon. Fler studier behöver utföras för att ta reda på långtidseffekter, studier inkluderande fler olika typer av grupper samt undersökningar om zuranolon passerar över i bröstmjölk och påverkar det nyfödda barnet.
149

Serial Analysis of Gene Expression of Rat Liver Regeneration by Oval Hepatic Stem Cells / Serielle Analyse der Genexpression während der Rattenleberregeneration durch Ovalstammzellen

Cimica, Velasco 05 November 2004 (has links)
No description available.
150

Zirkulierende Nukleinsäuren als molekulare Marker zur Trächtigkeitsbestimmung beim Rind / Circulating nucleic acids as molecular marker for pregnancy detection in cattle

Mayer, Jennifer 26 June 2012 (has links)
No description available.

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