The responses of 15 rice cultivars to low temperature during germination were studied in order to develop appropriate techniques to identify rice genotypes suitable for direct-wet seeding in the cooler <I>Boro</I> season. Most rice cultivars showed more than 90% final germination over a range of temperatures. When tested at 13.7°C, cultivars differed in their final germination and rate of germination. The rates of germination at higher temperatures were significantly related to the rates of germination at lower temperatures. Thermal times to 50% final germination also differed significantly. Artificial ageing for 48 hours clearly separated the cultivars which had different K_i<I> </I>(initial seed viability). Such measures of physiological age and their relationship with final germination suggested that low quality seed exhibited reduced low temperature germination. Differences in rates and final germination at lower temperature of unaged seed suggested genotypic differences between cultivars. Inconsistency in rates of seed deterioration was seen contrary to conventional theory. Storage of seeds up to 9 weeks in simulated Bangladeshi conditions showed reductions in final germination tested at 11°C but not at 20°C. The rates of chitting and germination were increased by pregermination hydration treatments. Emergence of rice cultivars from soil was greater in constant than in alternating temperatures. Higher final emergence was associated with faster emergence. Thermal time to 50% and 80% emergence differed between cultivars. Many of the seedling growth parameters were higher in constant temperatures where the rate of germination was faster. The outcome of these experiments is to highlight the potential for comparing rates of germination of large numbers of genotypes relatively rapidly at higher temperatures as a measure to predict germination at lower temperatures.

<p> Energy balance components were measured over a coastal subarctic wetland in northwestern James Bay during the growing season. The Penman-Monteith combination model was used to determine surface and atmospheric controls on evaporation. The Priestley-Taylor combination model was used to calculate an evaporability parameter, a. Combining these two models resulted in determining the sensitivity of a to surface and atmospheric controls. </p> <p> Canopy, aerodynamic, and climatological resistances were influenced by onshore or offshore wind directions. Canopy resistance was dominant and showed a strong seasonal trend a averaged 0.78 and was influenced by wind direction a is most sensitive to canopy resistance, followed by vapour pressure deficit, net available energy, and aerodynamic resistance. </p> / Thesis / Bachelor of Arts (BA)

This dissertation research contained three studies. The first two studies were conducted to investigate the ability of ewes to rebreed while lactating during seasonal anestrus. Breeds studied included the Virginia Tech Out-of-season (OOS) Line, which is a wool line genetically selected to lamb in the fall, and the St. Croix, a hair breed of tropical origin thought to be lowly seasonal. When January-lambing ewes were exposed to rams while lactating in April, significantly more OOS than St. Croix ewes were marked by rams in the first 21 d and total 39 d of ram exposure (58.3 vs. 8.7%, P = 0.0003 and 95.8 vs. 43.5%, P < 0.0001). Percentages of ewes diagnosed pregnant (53.2%) and percentages of ewes lambing (41.3%) were not different between breeds. When March-lambing OOS ewes were exposed to rams while lactating in May, 52.9% of ewes were marked though only 20% of ewes exposed to rams gave birth to viable lambs. Both OOS and St. Croix ewes appear to be well suited to accelerated production systems involving 7 to 8 mo lambing intervals. However, reduction of lambing intervals to 6 to 7 mo appeared to have detrimental effects on fetal survival in OOS ewes. In a third study, alterations in endocrine profiles associated with differing degrees of hypothalamic sensitivity to estradiol-negative feedback and changing daylength in OOS, St. Croix, and Suffolk ewes in the absence of rams were investigated for 1 yr. The results show for the first time that based on progesterone profiles from intact ewes, St. Croix ewes do not have shorter anestrous periods than ewes of wool breeds, as previously thought. Based on luteinizing hormone profiles from ovariectomized ewes treated with estradiol implants, the duration of luteinizing hormone inhibition was shorter in OOS than Suffolk ewes (68 vs. 170.2 d, P = 0.02), but was not different from that found in St. Croix ewes (124.8 d). Specific roles for thyroxine and prolactin in timing the breeding season could not be assigned. This study was the first known use of the ovariectomized, estradiol-implanted ewe model to compare degree of reproductive seasonality in different breeds. / Ph. D.

No description available.

In Experiment 1, 12 cyclic mares were assigned randomly to one of two groups (n = 6/group): 1) Control, saline; and 2) GnRH, 100 mu g/h. Between 3 and 6 d after ovulation (Day 0), Alzet osmotic minipumps (Model 2ML1) containing saline or GnRH were placed subcutaneous and connected to a jugular infusion catheter. Five-min samples were collected from the intercavernous sinus (ICS) of 10/12 mares (5/group) during 8 h on Day 4, followed by an additional 6-h intensive sampling period 36 h after induced luteal regression (Day 6). Treatment with GnRH markedly increased (P < 0.01) secretion of LH during both luteal and follicular phases. During the luteal phase, treatment with GnRH eliminated the very large, intermittent secretory episodes of LH characteristic of controls and produced frequent episodes of LH release of short duration. In Experiment 2, 12 anovulatory mares and 3 mares with some residual follicular activity (n = 15) were used during the fall (December 5 to 20) and winter (February 15 to 29) seasons. Mares were assigned randomly to: 1) Control, 2) GnRH-20; continuous infusion of GnRH at 20 mu g/h, or 3) GnRH-100; continuous infusion of GnRH at 100 mu g/h. Treatments were administered subcutaneously for 14 d using Alzet minipumps. Both the 20- and 100-mu g/h treatments increased (P less than 0.01) mean circulating concentrations of LH compared to controls before the winter solstice, but mares did not respond to the GnRH- 20 dose after the winter solstice. GnRH-100 caused a seasonally-independent increase (P less than 0.0001) in follicle size and ovulation frequency compared to controls The equine gonadotrope responded to continuous administration of high-dose GnRH during both ovulatory and anovulatory seasons, but was less responsive late compared to early in the anovulatory season.

The southeast United States is prone to severe weather throughout the year. Despite technological advances, some severe weather events occasionally remain unwarned in this part of the country. Past studies examined the relationship between cloud-to-ground (CG) lightning and warm season severe weather episodes. The present study examined the relationship between cool season tornadoes and CG lightning, with a focus over the southeastern United States, where most cool season tornadoes occur. Data from the Storm Prediction Center and National Lightning Detection Network (NLDN) were used to investigate CG lightning properties within 50 km and one hour before tornado touchdown. This was completed over a period of 13 cool seasons from October 1989 through March 2002. Of 3325 tornado events, 2358 contained at least one NLDN-detectable flash. CG lightning attributes of peak current, multiplicity, and flash density compared well with those of prior warm season lightning research. Overall event frequency appeared to be lower than in the warm season. Almost all Central Plains events were accompanied by at least one NLDN-detectable flash. Up to 70% of tornado events near the Gulf of Mexico and Atlantic coasts contained no NLDN-detectable lightning. Although it is not known why this trend was observed, it is speculated that NLDN detection efficiency and/or storm structure differences may play a role in these observations. Warm season studies have correlated tornadoes with predominantly positive (>50% positive CG lightning), or PPCG storms. Gridded maps showed the greatest percentage and highest frequency of cool season PPCG storms across Kansas and Nebraska, with up to 70% of events associated with PPCG lightning. A secondary, albeit lower, frequency maximum extended 1° to 2° inland across Louisiana into North Carolina. This study also subjectively defined a storm with “enhanced” positive cloud-to-ground (EPCG) lightning as one containing >25% positive cloud-to-ground lightning, which corresponds to approximately the 75th percentile of all cool season tornadoes. This has lead to speculation that EPCG criterion may be a better indicator of the possibility of severe weather than the traditional PPCG criterion.

Apibendrinant literatūros apžvalgoje minėtus faktus yra aišku, jog mokslas įsiterpia į tiriamą problemą. Straipsnių, susijusių su reprodukcijos sutrikimų tyrimais, skaičius nuolat didėja. Galbūt dėl to, kad ES skiria daug dėmesio žemės ūkio plėtrai, galbūt konkurencingumas verčia ūkininkus nemažai lėšų skirti tyrimams, susietiems su reprodukcijos problemos išaiškinimu ir jos panaikinimu. Tyrimai atliekami visame pasaulyje, o atskirus rezultatus bandoma susisteminti, keliant įvairias hipotezes. Su ūkiu susijusios problemos sprendžiamos pasitelkiant architektus ūkio planavimui, oro ventiliavimo ir kondicionavimo, apšvietinimo bei kitus specialistus. Tačiau kaip stengiamasi išvengti problemų jų nuolat atsiranda. Iš išskirtų faktorių, įtakojančių paršavedės reprodukcinį pajėgumą, sezoniškumas yra bene svarbiausias elementas, o su juo susiję sutrikimai kelia nemažai diskusijų. Pagal gautus tyrimo rezultatus galime teigti, kad vasarą, esant aukštoms temperatūroms bei ilgam šviesos režimui, būtina keisti ūkinio pastato konstrukcijas, kad neužtrūktų kiaulaičių brendimo laikas. Sėkmingai reprodukcijos eigai keliami dideli reikalavimai: reikalingas kompetetingas personalas, aplinkos veiksnių kontrolė, dokumentavimas bei protokolavimias, atsakingumas ir kruopštumas. Apžvelgiant tyrimų rezultatus pagrindiniai paršavedės reprodukcinių savybių rodikliai žiemos sezono metu buvo geresni nei vasaros (vislumas 4,36 proc., pieningumas 7,7 proc., nujunkomo lizdo masė 8,57 proc. didesni)... [toliau žr. visą tekstą] / Summarizing the facts mentioned in the literature review it is obvious that science intervenes to the researched problem. The number of articles where the disorders of reproduction are researched is increasing. The reasons can be the big attention from EU to the development of agriculture, the fact that competitiveness makes the farmers to spend quite a lot of money on researches where the problems of reproduction are being explained and the ways to eliminate it are proposed. The researches are done all over the world and separate results are systemized, various hypotheses are being formed. Farm related problems are being solved with the help of architects to plan the farm, as well as the specialists of air ventilation and conditioning, illumination and other fields. But even if we try to avoid problems they occur. Among the highlighted factors influencing the reproduction capacities of sow, factor of seasons is almost the most important element, and the disorders related with it raise a lot of discussions. The light regime virtually doesn’t affect the reproduction capacities under the high temperature, so the heat stays the main reason of summer time infertility. Talking about the influence of seasons to the interval of weaning until the rutting it can be stated that in the optimal combination of air temperature and photoperiod, the reproduction capacities can be stimulated; however each factor separately can inhibit the reproduction. The results of this research shows that... [to full text]

Class of 2012 Abstract / Specific Aims: To assess the accuracy of the presenting signs and symptoms, diagnostic procedures, and treatments presented in the last twelve episodes of season five of the popular medical drama, House, MD. Methods: A descriptive retrospective evaluation of the accuracy and inaccuracies of episodes 13 to 24 in season five of the television series House, MD. The accuracy of the presenting signs and symptoms, diagnostic procedures, and treatment in each episode was rated on a scale of one to four. A rating of one described a correct and usual representation. A rating of two described a correct but somewhat unusual representation. A rating of three described a correct but extremely unusual representation. A rating of four described an incorrect representation. Each researcher independently rated the episodes, and then a collaborative rating was agreed upon by both researchers. Main Results: Results of the ANOVA test demonstrated a statistically significant difference between the three dependent variables (p=0.002). The Tukey HSD post-hoc test confirmed a significant difference between the accuracy of treatment when compared with signs and symptoms (p=0.012), and with diagnostic procedures (p=0.002). The average rating for the treatment variable was 1.58 (0.9), whereas the average ratings for the signs and symptoms and diagnosis variables were 2.75 ( 0.754), and 3 (1.128), respectively. Conclusions: The treatments presented in the last twelve episode of season five of House, MD were more accurate than both the presenting signs and symptoms and the diagnosis.

Class of 2014 Abstract / Specific Aims: To assess the accuracy of the presentation (signs and symptoms), the diagnostic procedures used to arrive at the final diagnosis, and the ultimate treatment performed in each of the last ten episodes of the first season of the television medical drama, House MD. Methods: A descriptive retrospective analysis of the accuracies and inaccuracies of episodes 13 to 22 in season one of the television series House, MD. The accuracy of each episode in regards to the presenting signs and symptoms, diagnostic procedures, and treatment was rated on a scale of one to four: 1) Correct and usual representation; 2) Correct but somewhat unusual representation; 3) Correct but extremely unusual representation; 4) Incorrect representation. Both researchers evaluated each episode on the above criteria independently, and a cooperative and final rating was chosen upon. Main Results: Results of the ANOVA test did not demonstrate a statistically significant difference between the three variables (p=0.581). A Tukey HSD post-hoc test was unable to confirm if there was a significant difference between the the three variables. The average rating for the presenting signs and symptoms was 2.50 (±0.707), and 2.30 (±1.160) and 2.10 (±0.568) for diagnostic procedures and treatment, respectively. Conclusion: There was no difference in accuracies between the presenting signs and symptoms, diagnostic procedures, or treatments in the last ten episodes of the first season of House,MD.

Class of 2014 Abstract / Specific Aims: The aim of this study was to evaluate the level of accuracy of medical information presented in the sixth season of the popular prime time medical drama, House M.D. Methods: The study was a descriptive, retrospective assessment of twelve episodes in the sixth season of the medical television show, House M.D. Three parameters were compared to reliable medical sources: signs and symptoms, diagnostic procedures, and medical treatment for the one primary medical problem portrayed in each episode. Three researchers reviewed each episode independently and rated the accuracy of each parameter. The accuracy of each dependent variable was rated on a scale of one to four (most to least accurate, respectively). After discussion, a consensus rating was determined for all three variables for all twelve episodes. Main Results: The average accuracy scores for the signs and symptoms, diagnostic procedures, and medical treatments were 2.08, 2.58 (ie.,least accurate), and 1.5 (ie., most accurate), respectively. The average accuracy score across the three parameters was 2.06 (correct but somewhat unusual). The one-way ANOVA analysis on the variables revealed a statistically significant difference among the groups, with a p value of 0.003. The Tukey HSD test confirmed the statistically significant difference between diagnostic procedures and treatment (p = 0.002). Conclusion: The treatments portrayed in twelve episodes of season six were judged more accurate than signs and symptoms and diagnostic procedures. The average accuracy score of the three groups determined that the medical information presented in the episodes seemed to be correct but somewhat unusual.