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Ecological Distribution and Community Analysis of Tardigrada From Choccolocco Creek, AlabamaRomano, Frank A., Barreras-Borrero, Blanca, Nelson, Diane R. 01 January 2001 (has links)
A seasonal survey of tardigrade populations in the riparian zone of the Choccolocco Creek, Alabama, was undertaken from August 1994 through December 1995. Six sites within the riparian zone were sampled in different portions of the creek. At each site, 3 trees with cryptogams were sampled six times during survey period. From a total of 108 samples, 1,588 tardigrades were extracted and individually mounted on slides in Hoyer's medium. The community was dominated (86%) by specimens in the genus Macrobiotus. One species of Echiniscus was new to science and will be described in a separate paper. No significant difference was found between tardigrade occurrence (total number of individuals) and season, moss genera, or three species. However, there was a significant relationship between the number of tardigrades and sites, indicating the need for additional replicate samples. Simpson's and Shannon-Wiener's species diversity indicated indicated that species richness and evenness were low. Jaccard's and Standard's community similarity indices suggested that the communities within the riparian zone were dissimilar along Choccolocco Creek.
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Formation and Development of Tropical Temperate Troughs across Southern Africa as Simulated by a State-of-the-art Coupled ModelErasmus, Magdel January 2019 (has links)
A Tropical Temperate Trough (TTT) is a type of weather system that links the tropics and the extra-tropics across southern Africa. TTT events have been studied statistically in detail, but very little research has been done to study this phenomenon dynamically and especially on a seasonal scale. This study therefore focuses on the predictability of the characteristics of TTTs across southern Africa on a seasonal scale, by using a state-of-the-art seasonal forecasting model, namely the GloSea5 developed by the UK Met Office. Gridded hindcast data for the months of November, December, January and February from 1996/1997 to 2009/2010 are compared to observed data. The different ensemble members of the GloSea5 model (with lead-times of 1 week up to 2 months) are first compared separately to the observed data, after which the model average, with a 0-month, a 1-month and a 2-month lead-time, is calculated and also compared to the observed dataset.
TTT events have distinctive characteristics during the formation and the development phases. Most prominent of these characteristics are the cloud bands associated with these weather systems, which have a north-west to south-east orientation and move from west to east across southern Africa. To identify the TTTs, daily outgoing long-wave radiation values are processed by a Meteorological Robot (MetBot), with a strict criterion to identify the cloud bands that characterise these systems. The MetBot’s algorithm produces the information needed to further investigate the different characteristics of TTTs, such as the frequency, the location and the intensity of these systems. Analysis of the MetBot output includes calculating the Root Mean Square Error, the percentage error and in some cases the percentage deviation of the number of cloud bands, as well as the anchor point, the centroid position, the area, the tilt and the minimum and maximum OLR values of the cloud bands.
This investigation revealed that the characteristics of TTT events can to some extent be predicted on a seasonal scale for the summer rainfall season of southern Africa. The model used in this study fared particularly well with a 1-month lead-time forecast (compared to a 0-month and a 2-month lead-time forecast). The intensity and the location of the cloud bands associated with TTT events are forecast with a smaller percentage error than the frequency of these systems, as the frequency of TTTs tend to be significantly under-predicted by the model. For some predicted quantities, such as the area of the cloud bands, a bias-adjustment is necessary which produces significantly better results with smaller percentage errors. In the conclusions, suggestions are made on possible future studies, and how to develop this study further to create seasonal forecasts with higher skill with special regards to TTT events. / Dissertation (MSc)--University of Pretoria, 2019. / Geography, Geoinformatics and Meteorology / MSc / Unrestricted
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The effect of seasonal cattle grazing on California bighorn sheep habitat useSteinkamp, Melanie J. 01 May 1990 (has links)
The effect of seasonal cattle grazing on a newly reintroduced
population of California bighorn sheep (Ovis canadensis californiana) in
Big Cottonwood Canyon, Idaho, was studied. The hypothesis that bighorn
sheep avoid cattle was tested. The issue of avoidance between bighorn
sheep and livestock is arguable. Some studies have found that bighorn
sheep avoid cattle while others have found no response of bighorn sheep
to cattle.
Evidence was found to document the avoidance of cattle by bighorn
sheep. The size of the bighorn's home range and core area decreased
with the movement of cattle into areas of high bighorn use. As cattle
were moved into bighorn core areas, sheep responded by relocating.
Bighorn sheep decreased their distance to escape terrain as cattle moved
closer. The level and location of human disturbance on the study area
did not have any effect on bighorn sheep movements or how sheep used the
habitat.
The severity of response observed is in marked contrast with the
response of established bighorn populations to cattle. I suggest that
newly reintroduced bighorn sheep are extremely sensitive to disturbance
as a result of relocation trauma. Sensitivity may diminish over time.
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Seasonal Habits and Habitat of the Ruffed Grouse in the Wellsville Mountains, UtahPhillips, Robert L. 01 May 1965 (has links)
The ruffed grouse (Bonasa umbellus incana) inhabits much of the deciduous woodland of northern and central Utah. Its distribution is confined mainly to the Wasatch and Uinta mountain ranges. It has been observed in willows (Salix spp.) at 5, 000 feet elevation and in Douglas-fir (Pseudotsuga menziesii) at 9,000 feet.
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Seasonal trend and clinical presentation of Bacillus cereus bloodstream infection: association with summer and indwelling catheter / Bacillus cereus血流感染症発生の季節性変動と患者の臨床背景に関する研究Kato, Karin 25 July 2016 (has links)
Springer and European Journal of Clinical Microbiology and Infectious Diseases, 33, 2014, 1371-79, Seasonal trend and clinical presentation of Bacillus cereus bloodstream infection: association with summer and indwelling catheter, K. Kato & Y. Matsumura & M. Yamamoto & M. Nagao & Y. Ito & S. Takakura & S. Ichiyama, figure number 2, original copyright notice is given to the publication in which the material was originally published, by adding; with kind permission from Springer Science and Business Media / 京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19922号 / 医博第4142号 / 新制||医||1017(附属図書館) / 33008 / 京都大学大学院医学研究科医学専攻 / (主査)教授 中川 一路, 教授 佐藤 俊哉, 教授 玉木 敬二 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
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Migration of Elk (Cervus canadensis) and Barriers to MovementWatkins, Levi 21 April 2023 (has links) (PDF)
Movement patterns of animals are varied, complex, and can be influenced by environmental and anthropogenic factors. One form of animal movement, migration, is influenced by environmental factors that alter the timing, duration, intensity, and likelihood of migration. Additionally, features of the landscape, both natural and anthropogenic, can alter how animals move through their seasonal and home ranges. Movement patterns can be impeded or prevented by features such as railroads, rivers, and roads. Here we explore characteristics of elk (Cervus canadensis) migration by evaluating the strategies of migration exhibited and the factors that influence migration of elk in central and eastern Utah. In addition we determine landscape features that act as barriers to movement of elk. In the first chapter, we characterize migration of elk, and examine the influence of environmental factors have on the propensity and intensity of migration. In the second chapter, we determine barriers to movement and if the identified barriers could be better used as management area boundaries.
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Epidemiology, Aphid Vectors, Impact and Management of Tobacco Etch Potyvirus in Hot Peppers in JamaicaMcDonald, Sharon Angella 22 March 2001 (has links)
Production of hot peppers, Capsicum spp., in Jamaica is constrained by the aphid-transmitted potyviruses, tobacco etch virus (TEV) and potato virus Y (PVY). The virus epidemiology was not understood and no effective virus management system existed for these viruses. This study sought to identify possible management strategies for aphid-transmitted viruses of hot peppers in Jamaica, using TEV and Capsicum chinense, var. 'Scotch Bonnet' and 'West Indian Red', as models.
Field spread of TEV to pepper was mainly by secondary spread from primary infections. Secondary infections were spatially correlated to primary infections for up to 25 meters. Natural infections of TEV were associated with aphid flight activity. Over 30 species of aphids were collected on pepper farms in St. Catherine parish. These aphids included five known vectors of TEV, Aphis gossypii Glover, A. craccivora Koch, A. spiraecola Patch, Lipaphis erysimi Hille Ris Lambers and M. persicae (Sulzer), and 12 new records for Jamaica, Aphis amaranthi Holman, Brachycaudus helichrysi (Kaltenbach),Capitophorus hippophaes (Walker), Geopemphigus floccosus (Moreira), Hysteroneura setariae (Thomas), Lipaphis erysimi Hille Ris Lambers, Rhopalosiphum padi (Linnaeus), Schizaphis graminum (Rondani), Schizaphis rotundiventris (Signoret), Trichosiphonaphis poligoni (van der Goot), Uroleucon ambrosiae complex (Thomas) and Uroleucon pseudoambrosiae (Olive). A. amaranthi and U. ambrosiae were associated with TEV spread. Weeds on and near farms influenced the abundance and species of aphids captured.
West Indian Red pepper showed tolerance to TEV. Scotch Bonnet pepper yield reduction was greater if plants were infected with TEV during the vegetative stage through flower initiation rather than after the start of fruit set. Stylet oil and reflective mulch used together delayed the incidence of TEV in pepper plots for over two months. TEV management programs should aim to delay the virus from infecting peppers during the first two months after transplanting. A risk analysis is proposed for management of TEV and other aphid-borne viruses. / Ph. D.
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The Epidemiology of SARS-CoV-2 and Seasonal Respiratory Viruses in Ottawa, Ontario During the COVID-19 PandemicHeiskanen, Aliisa 23 November 2023 (has links)
This thesis aims to describe the epidemiology of SARS-CoV-2 and other seasonal respiratory viruses (SRV) in the Ottawa region and determine if there are demographic or occupational risk factors associated with viral infection. This was accomplished in three articles: a rapid review of the literature evaluating SARS-CoV-2 seroprevalence in transit users, an account of SRV activity in Ottawa, Ontario from August, 2018 to January, 2022, and an analysis of coronavirus (CoV) incidence and prevalence in several at risk groups. Results indicated a reduction in SRV incidence during the COVID-19 pandemic correlated with the introduction of non-pharmaceutical public health measures. SARS-CoV-2 seroprevalence indicative of natural infection was not greater in population groups hypothesized to be at greater risk of infection, such as transit users and those exposed to children. Lower socioeconomic status and racial or ethnic minority were consistently associated with higher SARS-CoV-2 seroprevalence. SRVs are expected to resurge and co-circulate with SARS-CoV-2. Results from this thesis suggest those of ethnic minority, low income or immunocompromised individuals may at greater risk.
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Seasonal Movements of the Sandstone Falls Population of Walleye in the Lower New RiverPhillips, Taylor K. 24 September 2014 (has links)
No description available.
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The Taber Well Site (33HO611): A Seasonally Occupied Lithic Reduction Site in Southeastern OhioPeoples, Nicole M. January 2004 (has links)
No description available.
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