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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.
121

Innovative Approaches for Addressing Concentrated Flow in Agricultural Fields

Pease, Jessica Erin 01 December 2013 (has links)
Riparian buffers are a commonly utilized best management practice (BMP) for mitigating non-point source pollution from agricultural fields. This practice is most effective when runoff enters the buffer as sheet flow. However runoff from becomes concentrated and forms concentrated flow paths (CFPs) breaking through the buffer in critical erosional areas. These critical areas can be determined prior to the implementation of a BMP such as a riparian buffer through incorporation of the Revised Universal Soil Loss Equation (RUSLE) with Geographic Information Systems (GIS). This approach utilizes field characteristics with hydrological processes in order to determine the erosion risk areas from observed field data throughout an entire watershed. In order to re-establish a riparian buffer in critical areas managers need a method that can prevent erosion and the loss of top soil. This study evaluates an innovative method, "Buffer in a Bag", used to restore riparian buffer benefits and to prevent further erosion in CFPs. There were three different treatments initiated for this study the first two treatments the "Buffer in a Bag", and Hand-Planted were implemented prior to the broadcasting of switchgrass seed. The final treatment was the Control, which required no planting within the treatment plot. The "Buffer in a Bag" treatment utilized the placement of giant cane rhizomes within burlap bags along the channel of concentrated flow. The hand planted treatment utilized the placement of giant cane rhizomes planted in the agricultural field adjacent to the path of concentrated flow. The presence of these CFPs breaking through riparian buffers has been noted, but the actual significant soil erosion occurring within the CFP and in the adjacent field has yet to be quantified. Through the use of topographical surveys and geostatistical analysis to produce digital elevation models (DEM) of in-field elevation changes the hydrological processes and volumetric difference for CFPs can be determined. The goal was to define the variability and the spatial pattern from the data as a means of providing comparisons between subsequent survey periods over time and space to estimate the difference and movement of sediment within CFPs. The volumetric differences found when comparing the DEMs between survey periods provide a quantifiable method for evaluating the implementation of a treatment, such as the "Buffer in a Bag". Using geostatistical analysis of volumetric difference between the treatment plots determined that that there was no significant difference between the CFP's over the study period. The mean percentage volumetric difference within the treatment plots between "Buffer in a Bag", Hand-Planted, and Control treatments were -2.49%, -3.72%, and -2.37%, respectively. There was overall net erosion across all treatments with the erosion and accumulation being significantly different across the survey periods for all the treatment CFPs. The mean percentage volume loss across treatments and survey periods varied from positive 10% accumulation to negative 15% erosion for overall loss when looking at each individual survey and CFP. The displayed loss of valuable topsoil and continued expansion of these concentrated flow paths emphasis the need for research in further management applications. There needs to be an effective method developed to address the volumetric difference within CFPs forming in these high risk erosion areas. Using a GIS/RUSLE approach to indicate these high risk erosion areas will hopefully facilitate the prevention of the formation of concentrated flow paths prior to the implementation of a BMP, such as riparian buffers.
122

Časoprostorová analýza lavin a jejich rekonstrukce pomocí letokruhových dat smrku ztepilého (\kur{Picea abies}) v Krkonošském národním parku. / Spatiotemporal analyses of avalanches and their reconstruction by the mean of tree-rings of Norway spruce (\kur{Picea abies}) in the Giant Mountains National Park.

JANDOVÁ, Veronika January 2015 (has links)
Various dendrochronological methods for avalanche reconstructions was applied on tree-ring records of dominant Norway spruce (Picea abies) in the Giant Mountains National Park. The individual growth chronologies from studied avalanche paths (Pramenný důl, Navorská jáma, Pančavská stěna, Velká Studniční jáma and Úpská jáma) proved that climate is the main driving factor of intra-annual variation of tree growth. Traumatic resin ducts are formed with delay up to 5 years. Combination of two and more tree-ring characteristics is suitable for reconstruction of avalanche events. I achieved to reconstruct undocumented avalanches. I conclude that dendrochronology is suitable tool for avalanche reconstruction; however, high pollutant emission highly reduced the potential of gained results.
123

Larguras de escape em ressonâncias gigantes / Widths of giant resonances exhaust

Nilton Teruya 15 October 1993 (has links)
As energias e larguras de escape das Ressonâncias Gigantes, são calculadas utilizando-se técnicas de projeção visando incluir as ressonâncias de partícula-única nos cálculos de RPA (\"Random Phase Approximation\"). As equações de RPA obtidas são complexas, e as larguras de escape são interpretadas como sendo a parte imaginaria das soluções em energia. Os cálculos são feitos para a RGE1( O16 ) e RGE0 ( Zr90 ). Para o Zr90, os espectros das partículas emitidas pela RGE0, prótons e nêutrons, são calculados através do modelo híbrido. Devido à existência de mais do que um tipo de partícula sendo emitida, as analises são feitas dentro da aproximação de independência entre os canais de partículas no formalismo do modelo híbrido. / The energy and the escape of the Giant Resonances are calculated utilizing the projection to include the single-particle resonances in complex RPA (Random Phase Approximation) calculations. The escape widths are interpreted as the imaginary parts of the energy solution of the RPA equations. The Calculations are performed for the RGE1 ( O16 ) and RGE0 ( Zr90 ). For the Zr90 the spectra of the particles ejected by the RGE0, protons and neutrons, are calculated within the hybrid model. The analysis are made through the channels independence in the hybrid model formalism.
124

The Stability of the Giant Clam Holobiont over Time and during Bleaching Stress

Pappas, Melissa 12 1900 (has links)
The stability of marine photosymbiotic holobionts has major implications for the future of coral reef communities. This study aims to describe the stability of the Red Sea giant clam holobiont over the duration of one year and during induced bleaching stress under laboratory thermal manipulations. Tridacnid clams of the species Tridacna maxima were sampled at three reef locations near the central Saudi coast of the Red Sea. Associated Symbiodinium of Red Sea giant clams have previously been described to be part of only Clade A, which suggests a strong specificity in the clam-algal partnership, but specific types and potential shifting of types within this clade have not been examined for giant clams. The results from this study confirm that tridacnid symbiont types shift over time and the change between three A1 types suggests a biological and functional significance of two undescribed A1 Symbiodinium types. Experimental bleaching shows that Red Sea giant clams, although exposed to rather hot temperatures naturally, will bleach at 34°C after two weeks, and severely bleached clams likely will not recover. During bleaching, Symbiodinium types shift as well, and shift more drastically than seasonal shifts during the year. This shifting may be an evolved characteristic of the giant clam to aid in surviving major changes in the environment. However, more research is needed to determine if these holobionts are capable of keeping up with the global forecast of warming in reef environments.
125

Implications of irradiance for the Red Sea Tridacna giant clam holobiont

Rossbach, Susann 01 1900 (has links)
Giant clams (Tridacninae subfamily) are prominent members of Indo-Pacific corals reefs, including the Red Sea, where they play multiple roles and are of distinct ecological significance for these communities. Tridacninae stand out among other bivalves as one of the few molluscan groups that live in a symbiosis with dinoflagellate Symbiodiniaceae. This relationship is comparable to the symbiosis of corals and their associated algae, where the symbionts provide a substantial amount of the respiratory carbon demand of the host through their photosynthetic activity. Their photosymbiosis restricts the distribution of the Tridacninae holobiont (i.e. giant clam host, symbiotic algae and associated bacteria) to the sunlit, shallow waters of the euphotic zone, where organisms receive sufficient incident light to maintain their high rates of primary production and calcification. However, giant clams in these shallow reefs are simultaneously exposed to potentially high and damaging levels of solar (UV) radiation. This thesis includes research on the Red Sea Tridacna spp. holobiont from an ecosystem to microscale level. It assess the abundance and distribution of Red Sea giant clams, including their associated symbiotic microalgae and bacterial microbiome. Further, it describes the strong light-dependency of calcification and primary production of Red Sea Tridacna maxima clams and reports on the effective photo-protective mechanisms that have been evolved by these clams to thrive in shallow reefs, despite levels of high solar irradiance. Tridacninae developed effective behavioral mechanisms for photo-protection, by which the clam is able to flexibly adjust its shell gaping behavior to incident light levels within a narrow time frame. On a microscale, Tridacninae use advanced photonic structures (iridocytes) within their tissues to mitigate the potential negative effects of high solar UV radiation, and to promote the photosynthesis of their symbiotic algae. Understanding the role of the Tridacna spp. holobiont for Red Sea coral reefs, its contributions to overall productivity, and its abundances in the region may serve as a baseline for further studies on this charismatic invertebrate. It may also contribute to the conservation efforts from local to regional scales, and eventually aid the protection of Tridacninae in the Red Sea and elsewhere.
126

Maintenance Management Model under the TPM approach to Reduce Machine Breakdowns in Peruvian Giant Squid Processing SMEs

Gallesi-Torres, A., Velarde-Cabrera, A., León-Chavarri, C., Raymundo-Ibañez, C., Dominguez, F. 06 April 2020 (has links)
In recent years, the giant squid processing industry in Peru exhibited a 59% increase in exports with respect to 2018. According to estimates, this industry generates approximately 30,900 jobs per year. However, some SMEs experience low productivity, such as the PECEPE company, due to plant downtime. This represents 26% of the available time, which translates into the loss of 1760 tons every year. The most constraining external factor the sector faces is uncertainty in resource availability caused by changing weather conditions and informal fishing activities. Although there is a large number of research studies on the fishing industry and resource extraction, literature on processing plant operations is scarce. Within this context, this study seeks to promote a high impact sector in Peru, as well as fostering processing plant competitiveness and productivity. Hence, to address these issues, the authors propose a maintenance management model under the TPM approach. As part of the results from model implementation, a 39% decrease was reported in plant downtime, while maintenance costs also decreased by 16%, which, in turn, increased machine availability and production by 784 tons per year.
127

Acute Bilateral Ischemia of Fingers: An Unusual Complication of Temporal Arteritis

Jithpratuck, Warit, Wason, William M., Elshenawy, Yasmin 01 November 2010 (has links)
We describe the case of a patient with documented temporal arteritis, who presented two years into her course with acute digital ischemia, presumed secondary to small vessel vasculitis. To our knowledge, this complication of temporal arteritis has not been previously reported.
128

Platelet and Red Blood Cell Indices in Harris Platelet Syndrome

Naina, Harris V., Harris, Samar 01 June 2010 (has links)
Inherited thrombocytopenias, including inherited giant platelet disorders (IGPD) or macro thrombocytopenias are relatively rare, but their prevalence is likely underestimated from complexities of diagnosis and a spectrum of subclinical phenotypes. Harris platelet syndrome (HPS) is the most common IGPD reported from the Indian subcontinent. Of note there are an increased number of hemoglobinopathies reported from the geographic location. We analysed red blood cell and platelet indices of blood donors with HPS from the north eastern part of India and compared them with blood indices of blood donors of south India. We found a statistically significant lower platelet count in blood donors with HPS (median, range) 132 (71-267) vs. 252 (160-478) as compared to donors from south India (P < 0.001). Mean platelet volume (MPV) was higher in donors with HPS 13.1, (range 12-21.9 fl) as compared to donors from south India 7.35 (range 6-9.2 fl) (P < 0.001). This study showed that blood donors with HPS had a low median platelet bio-mass 0.17 (0.10-0.38%) vs. 0.19 (0.13-0.28%) in donors from south India. The platelet distribution width (PDW) was 17.4 (14.9-19.6) in donors with HPS vs. 16.38 (15.2-18.5) in south Indian blood donors (P < 0.001). Thirty-three donors with HPS had a normal platelet count with MPV more than 12 fL. Only donors with HPS had giant platelets and thrombocytopenia on peripheral blood smear examination. None of these donors had Dohle body inclusion in their leukocytes. Compared to donors from south India, donors with HPS had a significantly lower hemoglobin 13.8 (12-16.3 gm/dL) vs. 14.8 (12-18) respectively (P < 0.001) while red distribution width (RDW) was higher in HPS 13.6 (11.5-16.7) vs. 12.8 (11.4-15.1). However we did not find any statistically significant difference in MCV, MCH, MCHC between the two groups. Peripheral blood smear did not show any obvious abnormal red blood cell morphology. In the blood donors with HPS we found a statistically higher MPV, RDW and a lower platelet count and platelet biomass. A population-based study will be helpful in determining the existence of any hemoglobinopathies among subjects with HPS.
129

Autologous skin reconstruction by combining epidermis and acellular dermal matrix tissue derived from the skin of giant congenital melanocytic nevi / 母斑組織由来表皮および脱細胞化真皮を用いた皮膚再生

Pham Hieu Liem 24 March 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18178号 / 医博第3898号 / 新制||医||1004(附属図書館) / 31036 / 京都大学大学院医学研究科医学専攻 / (主査)教授 宮地 良樹, 教授 羽賀 博典, 教授 山下 潤 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DGAM
130

The Gastrointestinal Tract Microbiota of the Obligate Bamboo Foragers, the Giant Panda (Ailuropoda Melanoleuca) and the Red Panda (Ailurus Fulgens)

Williams, Candace Lareine 14 August 2015 (has links)
Previously, the exact phylogenetic relationship between the giant panda (Ailuropoda melanoleuca) and the red panda (Ailurus fulgens) has been unclear, but with the advent of molecular sequencing technologies, these two animals are now known to be distantly related. Although taxonomically distinct, these two panda species have several things in common, primarily their almost exclusively bamboo diet, but also their similar physical adaptations to their diet and their sympatry in some locations. What was unknown was if their similarities also extended to their gastrointestinal tract (GIT) microbiota. Using next-generation 16S rRNA parallel sequencing technologies, we uncovered several factors that impact bacterial communities of the pandas and also found that the two panda species harbor distinct microbial communities. In general, the Firmicutes and the Proteobacteria dominate both pandas’ gut microbiomes, with lesser contributions by the Actinobacteria and the Bacteroidetes. However, for the red panda, sex, age, and season significantly alter GIT microbiota. For giant pandas, we found that bacterial communities differed significantly between their normal fecal samples and mucus excretions. Together, these data display the plasticity of their bacterial communities, with several factors shaping GIT microbiota. As both species are highly threatened, understanding the relationship between the panda and their gut microbiome has given insight into the overall health of these uniquely herbivorous carnivores.

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