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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.
161

Transgenic Overexpression of Ctrp3 Prevents Alcohol-Induced Hepatic Triglyceride Accumulation

Trogen, Greta, Bacon, Joshua, Li, Ying, Wright, Gary L., Degroat, Ashley, Hagood, Kendra L., Warren, Zachary, Forsman, Allan, Kilaru, Aruna, Clark, W. Andrew, Peterson, Jonathan M. 15 May 2018 (has links)
This study tested the ability of a novel adipose tissue derived cytokine, C1q TNF-related protein-3 (CTRP3), to prevent alcohol-induced hepatic lipid accumulation, or alcoholic fatty liver disease (ALD). Previous work has demonstrated that CTRP3 is effective at preventing high-fat diet-induced fatty liver; however, the potential of CTRP3 to inhibit ALD has not been explored. To test the potential protective effects of CTRP3, transgenic mice overexpressing CTRP3 (Tg) or wild-type littermates (WT) were subjected to one of two different models of ALD. In the first model, known as the NIAAA model, mice were fed control or alcohol-containing liquid diets (5% vol/vol) for 10 days followed by a single gavage of ethanol (5 g/kg). In the second model, the chronic model, mice were fed control or alcohol-containing diets for 6 wk with no gavage. This study found that CTRP3 reduced triglyceride accumulation in the chronic model of alcohol consumption by ~50%, whereas no reduction was observed in the NIAAA model. Further analysis of isolated primary hepatocytes from WT and Tg mice demonstrated that CTRP3 increased oxygen consumption in the presence of fatty acids, indicating that CTRP3 increases hepatic fatty acid utilization. In conclusion, this study indicates that CTRP3 attenuates hepatic triglyceride accumulation in response to long-term chronic, but not short-term, alcohol consumption.
162

Anonymous Mobile Consumer Analysis Platform

Saqib, Ehsan January 2016 (has links)
Advances in mobile communication, computing and positioning technologies allow the real-time acquisition of continuously changing locations of moving objects, e.g., users carrying location-aware mobile devices. The geocontextual analysis of these locations of users can reveal valuable mobile consumer patterns and enable a number of promising Business Intelligence (BI) services and desirable intelligent Location-Based Services (LBSes). However, as some exact user locations can be extremely sensitive while others can be used to link the users to his or her real-world identity, location traces of users must be anonymized.To facilitate these promising BI services and desirable intelligent LBS in a privacy preserving manner, the present paper proposes an Anonymous Mobile Consumer Analysis Platform (AMCAP) that based on the geocontextual analysis of anonymized location traces, in four phases, derives mobile consumer characteristics of its users in terms of Anomymous Mobile Consumer Profiles (AMCPs) and information about the dynamically changing spatio-temporal distribution of the users that is recorded in a spatio- temporal data warehouse of Anonymous Mobile Consumer Types (AMCTs). In the first phase, based on a number of spatio-temporal criteria the platform probabilistically associates a user’s generalized location, that is represented by an anonymization region with activity types that activity centers in the anonymization region can facilitate. In the second phase, based on the activity type inferred in phase one, the platform, in an online and incremental fashion, summarizes an Anonymous Mobile Consumer Profile (AMCP) for each of the users. In the third phase, the platform periodically groups the users based on their AMCPs into a number Anonymous Mobile Consumer Types (AMCTs). Finally, in the fourth phase, in order to capture the dynamically changing spatio-temporal distribution of the consumers and their characteristics, the platform, in an online and incremental fashion, records the frequency and duration of the visits of different AMCTs to different spatio-temporal regions.The AMCAP is empirically evaluated on the simulated movements of a subset of the population of Copenhagen, Denmark. Experiments regarding the accuracy of the AMCP construction reveal that the proposed activity type inference from anomymized regions is effective and can predict the actual activity of the users with an accuracy of 0.75 and a κ- value of 0.73. AMCPs are clustered into 7 AMCTs. The quality of AMCTs is evaluated by comparing it with Actual Consumer Types (ACTs) which are extracted from Actual Consumer Profiles (ACPs). In both the AMCPs and ACPs, the optimal number of clusters is 7. Meaning thereby that although AMCPs are blurred, they do not loose their inherent property of being clustered into the same of number of types as ACPs. The Adjusted Rand Index (ARI) (a measurement for similarity between two grouping of objects) between the AMCTs and ACTs is 0.3 which is significantly higher than the random assignment where ARI value is -0.0000247. Computational performance evaluations show that a relational DBMS-based prototype implementation of the AMCAP on a single machine can process 50,000 anonymization rectangles in 20 seconds. Based on the assumption that during any given 5-minute interval no more than 10% of the users submit an anonymization region, it is extrapolated that the prototype is capable to perform in real-time the geocontextual analysis (i.e., phases 1, 2, and 4) of anonymized location traces of 7 million users. Finally, to illustrate the utility of the information that is derived by the AMCAP a number of derived BI services are discussed.
163

Heatwave Events and Mortality Outcomes in Memphis, Tennessee: Testing Effect Modification by Socioeconomic Status and Urbanicity

Li, Ying, Akkus, Cem, Yu, Xinhua, Joyner, Andrew, Kmet, Jennifer, Sweat, David, Jia, Chunrong 02 November 2019 (has links)
Heatwave studies typically estimate heat-related mortality and morbidity risks at the city level; few have addressed the heterogeneous risks by socioeconomic status (SES) and location within a city. This study aimed to examine the impacts of heatwaves on mortality outcomes in Memphis, Tennessee, a Mid-South metropolitan area top-ranked in morbidity and poverty rates, and to investigate the effects of SES and urbanicity. Mortality data were retrieved from the death records in 2008–2017, and temperature data from the Applied Climate Information System. Heatwave days were defined based on four temperature metrics. Heatwave effects on daily total-cause, cardiovascular, and respiratory mortality were evaluated using Poisson regression, accounting for temporal trends, sociodemographic factors, urbanicity, and air pollution. We found higher cardiovascular mortality risk (cumulative RR (relative risk) = 1.25, 95% CI (confidence interval): 1.01–1.55) in heatwave days defined as those with maximum daily temperature >95th percentile for more than two consecutive days. The effects of heatwaves on mortality did not differ by SES, race, or urbanicity. The findings of this study provided evidence to support future heatwave planning and studies of heatwave and health impacts at a coarser geographic resolution.
164

Seasonal Precipitation Variability and Gully Erosion in Southeastern USA

Luffman, Ingrid, Nandi, Arpita 01 April 2020 (has links)
This study examines the relationship between gully erosion in channels, sidewalls, and interfluves, and precipitation parameters (duration, total accumulation, average intensity, and maximum intensity) annually and seasonally to determine seasonal drivers for precipitation-related erosion. Ordinary Least Square regression models of erosion using precipitation and antecedent precipitation at weekly lags of up to twelve weeks were developed for three erosion variables for each of three geomorphic areas: channels, interfluves, and sidewalls (nine models in total). Erosion was most pronounced in winter months, followed by spring, indicating the influence of high-intensity precipitation from frontal systems and repeated freeze-thaw cycles in winter; erosion in summer was driven by high-intensity precipitation from convectional storms. Annually, duration was the most important driver for erosion, however, during winter and summer months, precipitation intensity was dominant. Seasonal models retained average and maximum precipitation as drivers for erosion in winter months (dominated by frontal systems), and retained maximum precipitation intensity as a driver for erosion in summer months (dominated by convectional storms). In channels, precipitation duration was the dominant driver for erosion due to runoff-related erosion, while in sidewalls and interfluves intensity parameters were equally important as duration, likely related to rain splash erosion. These results show that the character of precipitation, which varies seasonally, is an important driver for gully erosion and that studies of precipitation-driven erosion should consider partitioning data by season to identify these drivers.
165

Evidence for Unusual Size Dimorphism in a Fossil Ailurid

Fulwood, Ethan L., Wallace, Steven C. 24 September 2015 (has links)
A second nearly complete skeleton of the fossil ailurid Pristinailurus bristoli was recently recovered from the Hemphillian (late Miocene) Gray Fossil Site of northeast Tennessee. It appears to be significantly larger than the previously known skeleton of P. bristoli, which was surprising as the living red panda Ailurus fulgens is thought to be generally monomorphic, including between sexes. Here the presence of significant size difference in the geometric means of cranial and postcranial measurements and canine area in the two specimens of P. bristoli is tested relative to the distribution of size differences in intersex and intrasex pairs of A. fulgens. The presence of sexual dimorphism in these dimensions is also assessed in A. fulgens using t-tests. We report the first evidence of sexual dimorphism in both upper and lower canine area in A. fulgens. We also found evidence of significantly greater body size difference in the two specimens of P. bristoli than that present in A. fulgens. This could reflect a variety of causes, including the presence of multiple species or subspecies, a greater range of ecologically driven variability, or the presence of sexual dimorphism. We argue tentatively for sexual dimorphism as the most plausible explanation for the apparent size range of P. bristoli.
166

Land, Lava, and Disaster Create a Social Dilemma After the 2018 Eruption of KīLauea Volcano

Houghton, Bruce F., Cockshell, Wendy A., Gregg, Chris E., Walker, Brett H., Kim, Karl, Tisdale, Caroline M., Yamashita, Eric 01 December 2021 (has links)
No description available.
167

On the Presence of Eunectes Murinus (Squamata, Serpentes) From the Late Pleistocene of Northern Brazil

Hsiou, Annie Schmaltz, Winck, Gisele R., Schubert, Blaine W., Ávilla, Leonardo 01 January 2013 (has links)
Brazilian late Pleistocene snakes have an extensive fossil record and are recognized for southern, northeastern and northern regions of this country. This fossil record is represented by the families Boidae, 'Colubridae', Viperidae and Elapidae. Here is presented the first record for Eunectes Wagler for the late Pleistocene of the Brazilian northern region. The material described is a single incomplete dorsal vertebra, and although it shares several vertebral features with most Boidae taxa, it can be distinguished from all other boids because is a robust and wide vertebra with a slightly depressed neural arch, relatively thick and robust zygosphene with a prominent median turbercle. The taxonomic allocation to E. murinus (Linnaeus) is based on the exceptionally large size of the vertebra. The discovery of E. murinus in the late Pleistocene of Tocantins State indicates the presence of a large body of water in a region that has previously been interpreted as relatively arid during this time.
168

On the Presence of Eunectes Murinus (Squamata, Serpentes) From the Late Pleistocene of Northern Brazil

Hsiou, Annie Schmaltz, Winck, Gisele R., Schubert, Blaine W., Ávilla, Leonardo 01 January 2013 (has links)
Brazilian late Pleistocene snakes have an extensive fossil record and are recognized for southern, northeastern and northern regions of this country. This fossil record is represented by the families Boidae, 'Colubridae', Viperidae and Elapidae. Here is presented the first record for Eunectes Wagler for the late Pleistocene of the Brazilian northern region. The material described is a single incomplete dorsal vertebra, and although it shares several vertebral features with most Boidae taxa, it can be distinguished from all other boids because is a robust and wide vertebra with a slightly depressed neural arch, relatively thick and robust zygosphene with a prominent median turbercle. The taxonomic allocation to E. murinus (Linnaeus) is based on the exceptionally large size of the vertebra. The discovery of E. murinus in the late Pleistocene of Tocantins State indicates the presence of a large body of water in a region that has previously been interpreted as relatively arid during this time.
169

Gully Erosion and Freeze-Thaw Processes in Clay-Rich Soils, Northeast Tennessee, USA

Barnes, Nicolas, Luffman, Ingrid, Nandi, Arpita 01 December 2016 (has links)
This study examines gully erosion in northeast Tennessee hillslopes in the Southern Appalachian Valley and Ridge physiographic province, where a thick sequence of red clay Ultisols (Acrisol, according to the World Reference Base for Soil) overlies dolomite and limestone bedrock. The role of freeze-thaw processes in gully erosion was examined weekly from 6/3/2012 to 9/17/2014 using a network of n = 78 erosion pins in three geomorphic areas: channels, interfluves, and sidewalls. Freeze-thaw days were identified using meteorological data collected on site. When freeze-thaw days occurred, erosion and deposition increased and gully conditions were more dynamic. When daily temperature did not plunge below freezing, more stable gully conditions persisted. Ordinary Least Square regression models of erosion pin length using freeze-thaw events explained significant portions of variability in channels (R² = 0.113, p < 0.01), interfluves (R² = 0.141, p < 0.01), and sidewalls (R² = 0.263, p < 0.01). Repeat analysis on only the winter-spring months minimally improved the sidewall model (R² = 0.272, p < 0.01). Erosion in interfluves exhibited a lagged effect, and was best correlated to freeze-thaw events during the prior period while erosion in channels and sidewalls was related to freeze-thaw events in the current week. Of the three geomorphic areas studied, sidewall erosion was best modeled by freeze-thaw events which contribute to widening of gullies through mobilization of sediment and mass wasting. This research demonstrates that freeze-thaw processes are a significant contributor to erosion in gully channels, interfluves, and especially sidewalls, and therefore temperature variability should be considered in erosion studies in similar climates.
170

Anatomical Study of the Auditory Region of Arctotherium Tarijense (Ursidae, Tremarctinae), an Extinct Short-Faced Bear From the Pleistocene of South America

Arnaudo, Maria Eugenia, Bona, Paula, Soibelzon, Leopoldo Hector, Schubert, Blaine W. 01 December 2016 (has links)
Here we present the most detailed morphological study of the auditory region of a tremarctinae bear, Arctotherium tarijense Ameghino. In addition, we provide new anatomical information of the Tremarctinae inner ear, such as coplanarity and deviation from orthogonality of the semicircular canals, as an approach to infer the head movements which encountered the extinct forms in locomotion. Based on morphological comparisons, A. tarijense exhibits the following particular features: the cavum tympani presents the highest relative volume compared with other ursids; the processus paraoccipitalis has a foramen that is absent in other tremarctines; there is only one (ventral) recess in the anterior region of the cavum tympani; and the recessus epytimpanicus is the smallest for all ursids studied. In relation to the inner ear, A. tarijense shows the lowest values of orthogonality deviation and highest scores of locomotor agility. Based on this, is possible to make a preliminary proposal that this species had a relative high vestibular sensibility and therefore a better ability to explore different kind of habitats. However, this hypothesis might be contrasted among bears taking into account the orientation of each semicircular canal in a phylogenetic framework.

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