• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 355
  • 270
  • 58
  • 46
  • 30
  • 25
  • 16
  • 13
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 5
  • Tagged with
  • 1009
  • 136
  • 106
  • 106
  • 99
  • 70
  • 64
  • 58
  • 55
  • 54
  • 52
  • 51
  • 48
  • 46
  • 46
  • 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.
181

Individual, Social, and Seasonal Behavior of the Thirteen-Lined Ground Squirrel (Spermophilus tridecemlineatus)

Wistrand, Harry E. 01 1900 (has links)
The purpose of this study is to provide a qualitative, detailed description of individual and social behavior in a free-living population of thirteen-lined ground squirrels. Behavioral differences in relation to various periods of the annual cycle are also evaluated.
182

Seasonal Changes of Fecal Coliforms

Scheuerman, Phillip R., Rhodes, C. M., Wheat, T. D., Mullins, J., Payne, Samuel 18 April 1996 (has links)
No description available.
183

Variation of the Symbiodinium Community Composition in Scleractinian Corals along a Cross-shelf and Depth Gradient

Mejia Restrepo, Alejandro 12 1900 (has links)
Corals form a symbiotic relationship with photosynthetic zooxanthellae from the genus Symbiodinium; the breakdown of this symbiosis results in the phenomenon known as coral bleaching. This relationship is especially vulnerable to high temperature stress, although corals may survive if they have resistant types of symbionts, or switch their community composition towards them. To assess the variation of the symbiont community in different environmental conditions, I recorded the temperature and collected samples from six scleractinian coral species and one calcifying hydrozoan, in two inshore, two mid-shelf, and two offshore reefs at 1, 15, and 30m depth, analyzing Symbiodinium diversity using Next Generation Sequencing with the SymPortal profile typing approach. The temperature was very similar for all points in winter, when coral samples were collected, but variation between points increased until a maximum at summer, with the shallower parts of the inshore reefs showing higher temperatures and the points at 30m depth showing the lowest. The Symbiodinium composition was more similar between samples of the same host species than among samples of the same reefs or depths. Coral species from the Pocilloporidae family and Millepora dichotoma showed specific association with different profile types, specifically, intragenomic variants of Symbiodinium type A1, which appears to be dominant in the Red Sea although it has not been reported for these species in other regions. The other species showed specific associations with types previously reported in other regions, mostly from clade C and D, although also having different types and intragenomic variants. For most cases, certain profile types, which can reflect different species or populations, appeared to be dominant in particular environmental conditions, following a distribution related with depth, reef type, or both. In conclusion, this study showed that the Symbiodinium composition depends more on the host species than on the environmental conditions, and within each species the adaptation to environmental gradients can rely on tolerant symbiont species or populations characteristic of the Red Sea, or association with different types and clades that are common also in other regions.
184

Physiological study on the transgenerational timing mechanism in an aphid / アブラムシにおける世代を越える測時機構の生理学的研究

Matsuda, Naoki 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22281号 / 理博第4595号 / 新制||理||1659(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 沼田 英治, 准教授 森 哲, 教授 曽田 貞滋 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
185

Sezónní akumulátor tepla / Rock heat accumulator

Nguyen Khac, Hoang January 2020 (has links)
The aim of the thesis to explain the functionality of seasonal accumulation with an in-depth view on rock bed accumulator. The computational model is based on the project located in Attenkirchen, Germany. After the technical analysis of the model is carried out an economical review can be realized. To conclude the thesis an evaluation is made comparing an accumulation system with a more traditional one.
186

Geodetic constraints on the present-day motions of the Arabian plate and the southern Red Sea region

Viltres, Renier 11 1900 (has links)
The present-day kinematics and deformation of the Arabian plate and the southern Red Sea region involves interaction of tectonic and non-tectonic processes including plate subduction, continental collision, seafloor spreading, intraplate magmatism, continental transform faulting, microplate rotation, hydrological loading cycles, and anthropogenic activity. Therefore, good constraints on the rates and directions of relative plate motion, plate boundary locations, and rheological properties in the area are essential to assess seismic and volcanic hazards in the region. In this thesis, I combine Global Navigation Satellite System (GNSS) measurements from over 200 stations with kinematic block modeling to provide updated estimates of the present-day motions of the Arabian plate and the southern Red Sea region. Using the non-rigid residual motions and changes in GNSS station baselines, I provide quantitative constraints on the internal deformation for the Arabian plate at different spatial scales. In addition, I use the GNSS station response to seasonal water exchange in the Red Sea to make inferences of the lithospheric elastic properties beneath Arabia. The GNSS-derived velocity field indicates coherent motion of both the Danakil block in the southern Red Sea and the Arabian plate at present. Current motions in the southern Red Sea region, however, are inconsistent with previous interpretations and require an additional plate boundary in the area. My updated fault slip rates improved earlier estimates limited by the number and spatial distribution of GNSS stations, particularly for the Arabian-Indian plate pair, for which slower right-lateral strike-slip motions are predicted. Non-rigid residual velocities within the Arabian plate interior indicate that large-scale internal deformations are compensated internally. However, at a smaller scale, I identify several localities accommodating significant strain, mostly related to anthropogenic activity. Ground response to surface mass loading associated with water transport in the Red Sea suggests that the Earth’s elastic structure beneath the Arabian plate is 20% to 30% less stiff than global averaged (i.e., AK135-F planetary model). Still, the lithosphere beneath both the Danakil block and the Arabian plate remains strong despite being affected by significant faulting and magmatism associated with the Nubian-Arabian-Eurasian plate interaction.
187

Essays on testing for stationarity possibly with seasonality and a structural change / 季節性及び構造変化を伴う場合の定常性の検定に関する論文 / キセツセイ オヨビ コウゾウ ヘンカ オ トモナウ バアイ ノ テイジョウセイ ノ ケンテイ ニ カンスル ロンブン

Kurozumi, Eiji, 黒住, 英司 28 March 2000 (has links)
博士(経済学) / 甲第99号 / 155p / Hitotsubashi University
188

Estimating a dynamically adjusted carrying capacity output for Limpopo Province using seasonal forecasts and remote sensing products

Maluleke, Phumzile January 2016 (has links)
Rangelands are extremely important for livestock grazing purposes in South Africa. Grazing should thus be regulated in order to conserve grass, shrubs and trees thereby ensuring sustainability of rangelands. In South Africa, the existing national grazing capacity estimate was developed in 1993 and updated in 2005 using National Oceanic and Atmospheric Administration Advanced Very High Resolution Radiometer (NOAA-AVHRR) satellite data. Largely due to changing land use practices (as well as changing data availability), there exists a clear need to create a new estimate, making use of current available data. For Limpopo, a province shown to be prone to recent land degradation, droughts and climate change, developing such an updated carrying capacity (CC) product (adjusted monthly according to monitoring data and seasonal forecasts) may help support more sustainable agricultural practices. The main objectives of the study are to update current CC products and to create deviation maps from CC for several years with relevant data. For estimation of the CC product, input data have included Satellite Pour l'Observation de la Terre (SPOT) VEGETATION Dry Matter Productivity (DMP), vegetation map of 2009 and downscaled coupled model data (ECHAM4.5–MOM3-DC2). A tree density product of 2003, observed rainfall and secondary ground truth data are also used. Study results show that Remote Sensing (RS) and Geographic Information System (GIS) technology, Earth Observation System (EOS) data and products, climate data and ground truth data are successfully used in a series of steps, processes with modelling to ultimately estimate grazing capacity. It is clear that rainfall is a primary determinant of DMP. The Coupled General Circulation Model (CGCM) shows that the December-January-February (DJF) rainfall season is important as a predictor season for the November through to April (NDJFMA) DMP growing season for the Limpopo Province. This model can discriminate high and low DMP (and GC) seasons. This study shows that the DMP product can, with certain assumptions, be used as a proxy for grass biomass. There is a strong drive towards the application of seasonal forecasts in agriculture. This project demonstrates the development of a tailored forecast, an avenue that should be explored in enhancing relevance of forecasts to agricultural production. / Dissertation (MSc)--University of Pretoria, 2016. / Geography, Geoinformatics and Meteorology / MSc / Unrestricted
189

Sezonní proměnlivost v teritoriální aktivitě bobra evorpského (Castor fiber L.) / Seasonal variation of the territorial behaviour of the European beaver (Castor fiber L.).

Kadlecová, Hana January 2010 (has links)
The presented thesis deals with the temporal and spatial changes in activity of the European beaver (Castor fiber L.) during different seasons. Basic dataset was obtained by continuous telemetric monitoring of selected individuals in years 2008 and 2009 in two different geographical areas, namely in the Bohemian forest and in southern Moravia. The scope of the thesis was to record, evaluate and interpret the behavior of European beaver during the year. I focused myself especially on the beginning and end of activity in relation to incidence of sunrise and sunset, duration of stay in the field, changes in the size of actively-used area and time-duration and length of the movement. In cases where there were more active individuals monitored within the studied area, I also watched for their mutual interaction. In statistical analysis of gained data I also took into account the sex and age of the individuals. Beaver's behavior varies during the year. They are most active in spring and autumn, while in winter their activity decreases significantly. This observation is valid not only for the time duration and length of movement trajectories, but also for the size of actively-used area. The beginning of activity is strongly correlated with the sunset, while the end does not show any correlation with...
190

Doctor YouTube’s Opinion on Seasonal Influenza: A Critical Appraisal of the Information Available to Patients

Kallur, Akhil, Albalbissi, Ahmad, Carillo-Martin, Ismael, Boonpheng, Boonphiphop, Kallur, Lakshmi, Kherallah, Yaman, Mahajan, Akhilesh, Mahapatra, Shayan, Mohan, Kaushik, Mohan, Priyasree, Reddy, Keerti, Sankhyan, Pratyaksha, Lopez-Alvarez, Sonia, Youssef, Dima, El Abbassi, Adel M., Gonzalez-Estrada, Alexei 01 January 2020 (has links)
Background: Seasonal influenza is a respiratory illness caused by the influenza virus. During the 2017–2018 flu season, the Centers for Disease Control and Prevention noted approximately 959,000 hospitalizations and 79,400 deaths from influenza. We sought to evaluate the educational quality of informational videos pertaining to seasonal influenza on the popular social media forum, YouTube. Methods: Using the keywords “seasonal influenza,” all videos from 28 January to 5 February 2017 were included and analyzed for characteristics, source, and content. The source was further classified as healthcare provider, alternative-medicine provider, the patient and/or their parents, company, media, or professional society. Videos about other categories of influenza (e.g. swine or Spanish) or in foreign languages were excluded. A total of 10 blinded reviewers scored each video independently. Results: Overall, 300 videos were analyzed, with a median of 341.50 views, 1.00 likes, 0 dislikes, and 0 comments. Based on the average scores of videos by source, there was statistically significant difference in the average score among videos by video source (p < 0.01). Healthcare provider videos had the highest mean scores whereas alternative medicine provider videos had the lowest. Conclusions: Although the aforementioned video sources scored higher than others, these videos did not fulfill our criteria as far as educating patients thoroughly. Our data also suggest alternative medicine and patient source videos were misleading for patients. Clinical implications: Although videos by healthcare providers were a better source of information, videos on seasonal influenza were shown to be poor sources of valid healthcare information. This study reiterates the need for higher-quality educational videos on seasonal influenza by the medical community.

Page generated in 0.0864 seconds