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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.
1

Spatiotemporal analysis of flooding in Tennessee counties: 1996-2021

Afriyie, Emmanuel, Luffman, Ingrid 25 April 2023 (has links) (PDF)
Tennessee has a long history of floods that have caused property damage and loss of life. In the face of climate change and variability, it is imperative to look at trends to ascertain if there is a significant change in current flood regimes versus past flood events. Trend Analysis and Emerging Hotspot Analysis are useful geospatial tools that can effectively display changes over time and space. This study aims to evaluate the history of flood events in Tennessee to identify spatiotemporal trends and hot spots. A total of 902 flood events from 1996-2021 recorded in the National Oceanic Atmospheric Agency (NOAA) storm events database were analyzed using the number of events per county and the total damages per county at an annual time step. Two 26-year space-time cubes were built in ArcGIS Pro (version 3.0) for flood events and damages using an annual time step, with counties as the spatial unit. GeoGa software (version 1.20.0.22) was used to weight the distance between Tennessee counties to define a statistically significant neighborhood distance at 37km fixed distance. Trend Analysis and Emerging Hotspot Analysis was conducted to assess spatiotemporal trends in flooding events and damages (in dollars). Trend analysis revealed an increasing trend of flood events in eleven counties in middle Tennessee (Davidson, Wilson, Rutherford, Coffee, Marion, Putnam, Overton, Maury, Lawrence and Dickson counties) and Carter county in east Tennessee. Decreasing trends were observed in two counties (Lake and Bradley), all at a 90% or greater confidence level. Increasing trends in flood damages were identified in Cumberland, Putnam, Lawrence, Blount, Sullivan and Green counties, all in east and middle Tennessee. Decreasing trends were identified in Lake, Obion, Dyer, and Tipton, all in west Tennessee. East Tennessee was identified as a sporadic flooding hot spot (Hawkins, Green and Washington counties) with no significant hot spots in middle and west Tennessee. There were no hot spots nor cold spots in flood-related damages across Tennessee. The results indicate that flood events and related damages are decreasing in west Tennessee while parts of middle Tennessee and east Tennessee are experiencing increased flood events. This study is an important step to better understand spatiotemporal trends in flooding and flooding damages and will be useful in hazard mitigation planning in Tennessee at both state and county levels.
2

BAR MANAGEMENT AND CRIME: TOWARD A DYNAMIC THEORY OF PLACE MANAGEMENT AND CRIME HOTSPOTS

MADENSEN, TAMARA D. 05 October 2007 (has links)
No description available.
3

Förstudie till ett stadstäckande och öppet WiFi i Trollhättan

Bennehag, David, Wulcan, Alexander, Claesson, ommy January 2013 (has links)
Förstudien behandlar den tekniska delen av ett teoretiskt stadstäckande öppet WiFi i Trollhättan, Sverige. Trollhättans kommun beställde en förstudie från Högskolan Väst som skulle agera beslutsunderlag till hur de skulle ta ärendet vidare. Studien är begränsad till den tekniska biten, där bland annat val av utrustning, trådlösa tekniker och riskanalys av nätverket ingår. Arbetet varit väldigt teoretiskt inriktat med en metod som till största del består utav att samla information och kunskaper från vetenskapliga rapporter, teknikorienterade hemsidor och andra relaterade arbeten.De trådlösa standarder som jämfördes teoretiskt i förstudien var 802.11g och 802.11n. 802.11n valdes som den standarden som bäst passade just detta nätverk, främst för dess positiva egenskaper när det gäller täckning, hastighet och bakåtkompatibilitet. 802.11n seräven ut att garantera en säker framtid när det gäller implementering i mobila enheter. Föreslaget på utrustning består av två olika accesspunkter, antingen 2602e eller 3602e beroende på den slutgiltiga budgeten. Dessa produkter är från Cisco och klarade olikastresstester med bra resultat samtidigt som de stödde den föreslagna standarden 802.11n. WLAN controllern (Ciscos 5500-serie) som valdes ut stödjer det krav på antal accesspunkter som bestämts, samtidigt som den lämpar sig bra för eventuella framtidakrav. Routern till detta nätverk är en Cisco 891-router. Anledningen till att denna router valdes var för att den har 4 portar som kan ge ström över Ethernet till accesspunkterna. Säkerhetsanalysen gjordes med hjälp utav CORAS-metoden där det diskuteras vilka riskernätverket kan ställas inför och vad dessa risker kan få för konsekvenser. Försök till att hitta lösningar som var direkt applicerbara på det stadstäckande öppna nätverket gjordes även.Förstudien avslutas med en kostnadsberäkning av nätverket, baserad på andras tidigare arbeten och deras kostnader, speciellt från Jönköping, Helsingborg och Mountain View.
4

Mapping and analysing cancer incidence in South Africa / Samuel Jacobus Jansen van Rensburg

Van Rensburg, Samuel Jacobus Jansen January 2014 (has links)
The primary aim of this dissertation was to develop and validate a methodology for identifying spatial clusters (hotspots) of various paediatric cancers within South Africa by using GIS software. The Hotspot Analysis (Getis-Ord Gi*) Tool was used for this purpose. A series of spatial clusters (hotspots) were identified by the tool for each cancer type and these clusters were compared with the exiting literature regarding known environmental and other carcinogens. The quality of the cancer data used in the dissertation was however found to be questionable and significantly underreported. This caused the results of the tool to also be questionable. The dissertation therefore concluded that the tool could be successfully used to identify spatial clusters of cancer in principle. It was however found that the results of the tool needed to be viewed without caution in this dissertation due to the low quality of the cancer data used. / MSc (Geography and Environmental Management), North-West University, Potchefstroom Campus, 2014
5

Rural Housing Market Hotspots and Footloose In-migrants

Andersson, Eva K January 2012 (has links)
This study applies a housing market perspective on hotspots in northern, rural Sweden. It uses the concept ‘hotspot’ defined as places with rising house prices and in-migration of households with higher than average education and income. The focus rests on three places having the ideal characteristics of being a rural hotspot, located in three Swedish northern municipalities. These places are explored through ten interviews with ‘footloose’ households. The aim is to explore factors that shape rural housing market hotspots using stories from hotspot population households. The first reason for this study is that regional planning requests understanding to develop different regions and places for the future. Here the origins of hotspots are explored to understand the spread and sustainability of such developments. Second, housing markets in the countryside are more scantily investigated than in urban areas. In the unbalanced housing market with higher prices and limited supply in the urban areas hotspots in rural areas are not following traditional housing market theories, they are rather anomalies. Interviews with a specific footloose group of recent hotspot in-migrants are used in combination with knowledge about the housing market. Results show that although hotspots are locations with beautiful nature most households moved there because of finding jobs. The three areas have the ‘extra’ nature values and high status required for being a hotspot and a location for commuting to larger labor markets. The ‘footloose’ non-return migrants did find nice, cheaper housing that made them chose the area despite being strangers to the place. I suggest hotspots are the rare combination of footloose migrants and special places which make them difficult to develop elsewhere. / På jakt efter hotspots. Den svenska landsbygdens ojämna urbanisering" Lena Magnusson Turner (principal applicant) and Eva Andersson Formas – for the period 2009–2010
6

Mapping and analysing cancer incidence in South Africa / Samuel Jacobus Jansen van Rensburg

Van Rensburg, Samuel Jacobus Jansen January 2014 (has links)
The primary aim of this dissertation was to develop and validate a methodology for identifying spatial clusters (hotspots) of various paediatric cancers within South Africa by using GIS software. The Hotspot Analysis (Getis-Ord Gi*) Tool was used for this purpose. A series of spatial clusters (hotspots) were identified by the tool for each cancer type and these clusters were compared with the exiting literature regarding known environmental and other carcinogens. The quality of the cancer data used in the dissertation was however found to be questionable and significantly underreported. This caused the results of the tool to also be questionable. The dissertation therefore concluded that the tool could be successfully used to identify spatial clusters of cancer in principle. It was however found that the results of the tool needed to be viewed without caution in this dissertation due to the low quality of the cancer data used. / MSc (Geography and Environmental Management), North-West University, Potchefstroom Campus, 2014
7

Génétique de l'infertilité masculine / Human genetics of male infertility

Elinati, Elias 10 September 2012 (has links)
Le génotypage d’une famille jordanienne consanguine constituée de 5 frères globozoospermiques et de 3 frères fertiles sur puce Affymetrix, a permis d’identifier un nouveau gène responsable de la globozoospermie situé dans un intervalle de 6.4Mb en 12q14.2. Au regard de son expression prédominante dans le testicule et l’implication de son orthologue, chez C. elegans, dans la polarisation cellulaire, le gène DPY19L2 est un gène candidat parfait. Le gène, codant pour une protéine transmembranaire, est flanqué par deux séquences répétées (LCRs) qui partagent 96,5% d’identité. Dans une première étude, une délétion de 200Kb englobant l’ensemble du gène a été mise en évidence chez les 4 frères infertiles de cette famille jordanienne ainsi que chez 3 autres patients non apparentés. Nous avons ensuite recruté une plus grande cohorte de 54 patients. Parmi ces patients, 20 sont homozygotes pour la délétion de DPY19L2 et 7 sont hétérozygotes composites associant la délétion hétérozygote et une mutation ponctuelle. En outre, nous avons identifié, 4 patients avec des mutations ponctuelles homozygotes. Par conséquent, la fréquence d’implication de DPY19L2 s’élève à 66.7%. En tout, 9 points de cassures, regroupés en deux hotspots au sein des LCRs, ont pu être mis en évidence. Ceci confirme que le mécanisme sous-jacent de la délétion est une recombinaison homologue non allélique (NAHR) entre les LCRs. En conclusion, nous confirmons que DPY19L2 est le principal gène de la globozoospermie et nous élargissons le spectre des mutations possible dans ce gène. / Performing a genome wide scan by SNP microarray on a Jordanian consanguineous family where five brothers were diagnosed with complete globozoospermia, we show in a first study that the four out of five analysed infertile brothers carried a homozygous deletion of 200 kb on chromosome 12 encompassing only DPY19L2. The gene encodes for a transmembrane protein and is surrounded by two low copy repeats (LCRs). Very similar deletions were found in three additional unrelated patients. Later, we have pursued our patient screen by recruiting a largest cohort of patients. Out of a total of 54 patients analysed, 36 (66.7%) showed a mutation in DPY19L2. Out of 36 mutated patients, 20 are homozygous deleted, 7 heterozygous composite and 4 showed a homozygous point mutation. We characterized a total of nine breakpoints that clustered in two recombination hotspots, both containing direct repeat elements. These findings confirm that the deletion is due to a nonallelic homologous recombination (NAHR) between the two LCRs. Thus, Globozoospermia can be considered as a new genomic disorder. This study confirms that DPY19L2 is the major gene responsible for globozoospermia and enlarges the spectrum of possible mutations in the gene.
8

La concentration du crime et les caractéristiques de l'aménagement de l'espace urbain à Marseille / Crime density and characteristics of the built environment in Marseille

Fouillade Orsini, Hadrien 23 May 2018 (has links)
Il semble communément admis que l’espace et le crime sont intimement liés. L’origine sociale du délinquant et les caractéristiques sociales des quartiers criminogènes ont souvent été mises en avant comme facteurs explicatifs de la concentration de la délinquance. Pourtant la localisation du crime ne semble pas être due au hasard. L’espace joue un rôle primordial tant dans la manifestation du crime que dans sa persistance. Etudier le crime du point de vue géographique et de l’analyse spatiale nécessite à la fois une définition précise de l’acte ou du comportement illicite, mais également une quantification ainsi qu’une géolocalisation à l’échelle la plus fine possible. En France le niveau départemental voire communal représente le niveau le plus bas disponible en termes de statistiques criminelles. Cependant l’analyse de la relation entre l’aménagement de l’espace urbain et la distribution spatiale du crime nécessite une donnée à l’échelle de la rue. L’agglomération de Marseille a été retenue comme espace d’étude en raison de son profil économique et social particulier. La capitale régionale de Provence-Alpes-Côte d’Azur compte un nombre important de quartiers concernés par la nouvelle géographie prioritaire de la politique de la ville. Elle se caractérise aussi par son titre controversé de ville la plus criminogène de France. Cette idée forgée au cours du 20ème siècle a été alimentée par le rôle de Marseille comme principal port de l’Empire Colonial Français. Les marchandises illicites surent profiter des lignes commerciales régulières pour entrer sur le territoire national via le port. Au lendemain de la seconde guerre mondiale la ville devint la capitale mondiale de la transformation de la morphine-base et de l’exportation de l’héroïne jusqu’à ce qu’en 1969 le président des Etats-Unis d’Amérique : Richard Nixon décide de mener une lutte farouche contre le trafic de stupéfiants à destination de son pays. Entre récession économique et trafic dynamique de la drogue, Marseille est chaque année concernée par près d’une quinzaine d’homicides majoritairement liés à la guerre des voyous pour le contrôle du trafic de stupéfiants. Ces « règlements de compte entre malfaiteurs» d’après la désignation officielle ne représentent qu’une infime partie de la délinquance sévissant dans la commune. Cependant ces meurtres qui sont assez rares pour être systématiquement rapportés par les différents médias sont suffisamment nombreux pour permettre une cartographie de la délinquance suite au référencement de chaque homicide dans un système d’information géographique. Une fois les analyses spatiales de la distribution d’un semis de points effectuées, une analyse d’image par morphologie mathématique a été réalisée pour délimiter scientifiquement les zones de concentration du crime. L’objectif de la recherche consistant à identifier les caractéristiques de la configuration géographique de l’aménagement urbain qui permettent d’expliquer la distribution spatiale du crime. Différentes représentations de l’espace urbain et des réseaux spatiaux convertis en graphes primaux ou duaux ont été utilisées pour discerner les quartiers les plus isolés et à l’inverse les lieux les plus centraux et intégrés. Aux différents indices mathématiques de centralité calculés sur les réseaux spatiaux s’ajoute une représentation des interactions entre les espaces ouverts sous la forme d’un graphe conçu d’après la théorie de la syntaxe spatiale. Les différents indices calculés devant vérifier si les zones de concentration des règlements de compte entre malfaiteurs à Marseille sont systématiquement localisées dans des quartiers facilement accessibles comme le laisserait suggérer la présence d’un trafic de drogue dynamique ou au contraire dans des lieux ségrégés et difficiles d’accès pouvant expliquer la dégradation urbaine et sociale perceptible dans ces espaces. / It seems to be widely agreed that space and crime are closely related. The social origin of the offenders and social characteristics of criminogenic districts have frequently been brought forward as determining factors of crime density. However, crime does not seem to be located randomly. Space takes a primordial role both in the outbreak of crime and his persistence. Study of crime with a geographical approach and space analysis requires both a clear definition of criminal act or behaviour and a quantification as well as georeferencing of the events on a finer scale. In France, the departments nay the municipalities represent the lowest level in terms of crime statistics. Nevertheless, data at the street level are required in order to understand the relation between urban pattern and crime distribution. The city of Marseille has been chosen as the study area due to it’s particular economic and social profile. The capital city of region of Provence-Alpes-Côte d’Azur has a large number of neighbourhoods concerned by the new French urban policy. Marseille counts 35 "priority districts" taking up 35 squares kilometres where about 237 877 inhabitants lived according to the census of 2013, which represents 28% of the global population of the city. The bad reputation of Marseille known as the most criminal city of France was built during the 20th century when Marseille was the main port of the French Colonial Empire. Illicit goods were brought into the national territory through regular trade routes via the harbour. After the Second World War, Marseille became the world capital of heroin production and exportation until the president of the United States of the America, Richard Nixon, decided to put up a fierce battle against drug traffic to his country. Between economic recession and dynamic drugs traffic, Marseille is impacted by about fifteen murders every year, for the most part directly linked with the dealers’ war to control drug market. The settling of scores between criminals represents only a small portion of serious and petty crimes occurring each year within the municipal boundaries. Such assassinations are rare enough to justify a regular media coverage and frequent enough to generate crime mapping. Once the crime mapping of every assassination was done, a point pattern analysis was performed. Then, an image analysis with mathematical morphology was conducted in order to determine the influence area of the phenomenon. This step has allowed to determine the bandwidth of the Kernel density estimation applied to mark out the crime hotspots. The aim of this research is to determine which characteristics of the geographical pattern of the built environment could explain crime density in some locations. Do the spaces where settling of scores take place have identical specificities ? Do the crime hotspots drastically differ from other areas ? To detect segregated districts on one hand and central places on the other hand, different representations of the urban pattern and the road network have been used. Beyond the different mathematical measures of centrality calculated on spatial network, the representation of the interactions between the open spaces into a dual graph have been fulfilled in order to apply space syntax theory. Measures calculated according space syntax methodology should prove if crime hotspots in Marseille are systematically located in easily reachable areas as suggested by the presence of a dynamic drug trade or, on the contrary, in segregated neighbourhoods difficult to access, which could explain the social and urban degradation discernible in such locations.
9

Molecular mechanisms of recombination hotspots in humans

Noor, Nudrat January 2013 (has links)
Meiotic recombination involves the exchange of DNA between two homologous chromosomes, forming cross-overs and gene conversion events. The cross-over process is important for the proper segregation of chromosomes during meiosis, and drives genetic diversity. Human hotspots are enriched for a 13-bp motif, CCNCCNTNNCCNC; a close match to this motif occurs in about 40% of our cross-over hotspots. A DNA binding protein called PRDM9, having histone trimethyltransferase (H3K4me3) activity, binds the motif and is becoming established as a major determinant of recombination hotspots (narrow regions with high cross-over activity). This research aimed to understand the mechanisms involved in promoting PRDM9 binding to its target sites, and subsequently, initiating cross-over hotspot activity. We first explored the relationship between PRDM9 binding and DNA sequence, to directly confirm whether PRDM9 binds to the 13-bp hotspot motif using in-vitro gel-shift assays, and found that it does bind sequence specifically to the canonical 13-mer motif. PRDM9 is able to bind the motif in a highly selective manner, with certain single base pair changes abolishing binding. However, we observe that it is also able to tolerate degeneracy in its binding sites, as demonstrated by strong in-vitro binding to degenerate versions of the 13-bp motif. Hence, these results confirmed that PRDM9 is able to directly bind to the 13-bp hotspot motifs, and given that it can also tolerate degeneracy, this raised the question of why PRDM9 is able to bind only a subset of all such potential binding sites in the genome. To address this, a ChIP-seq analysis was performed to identify genome wide binding sites for PRDM9. This information also helped us to characterise binding sites and investigate if factors such as the local chromatin environment play a role in specifying PRDM9 binding tar- gets and hotspot formation. We were able to identify over 170,000 PRDM9 binding sites in the genome. Surprisingly, these binding sites were also enriched in promoter regions, however, bound sites in these regulatory regions showed low recombination activity. We found that PRDM9 is able to confer the H3K4me3 mark on all bound sites, even those without a pre-existing H3K4me2 mark. We also investigated the role of other chromatin related marks on PRDM9 binding and found that binding occurs in chromatin accessible, but nucleosome rich regions, whereas heterochromatin regions tend to inhibit binding. Further, for hotspot formation, it was seen that less chromatin accessible, nucleosome dense regions away from transcribed sites, are preferred. Hotspots tend to avoid regions marked by transcription activating histone modifications, however, these regions do not appear to inhibit PRDM9 binding itself. These results show how PRDM9 binding in the genome is dependent on both primary DNA sequence and the surrounding epigenetic factors. Together these factors promote binding and, with additional downstream factors, positioning of hotspot locations in the human genome.
10

Characterizing local biological hotspots in the Gulf of Maine using remote sensing data

Ribera, Marta 08 April 2016 (has links)
Researchers increasingly advocate the use of ecosystem-based management (EBM) for managing complex marine ecosystems. This approach requires managers to focus on processes and cross-scale interactions, rather than individual components. However, they often lack appropriate tools and data sources to pursue this change in management approach. One method that has been proposed to understand the ecological complexity inherent in marine ecosystems is the study of biological hotspots. Biological hotspots are locations where organisms from different trophic levels aggregate to feed on abundant supplies, and they are considered a first step toward understanding the processes driving spatial and temporal heterogeneity in marine systems. Biological hotspots are supported by phytoplankton aggregations, which are characterized by high spatial and temporal variability. As a result, methods developed to locate biological hotspots in relatively stable terrestrial systems are not well suited for more dynamic marine ecosystems. The main objective of this thesis is thus to identify and characterize local-scale biological hotspots in the western side of the Gulf of Maine. The first chapter describes a new methodological framework with the steps needed to locate these types of hotspots in marine ecosystems using remote sensing datasets. Then, in the second chapter these hotspots are characterized using a novel metric that uses time series information and spatial statistics to account for both the temporal variability and spatial structure of these marine aggregations. This metric redefines biological hotspots as areas with a high probability of exhibiting positive anomalies of productivity compared to the expected regional seasonal pattern. Finally, the third chapter compares the resulting biological hotspots to fishery-dependent abundance indices of surface and benthic predators to determine the effect of the location and magnitude of phytoplankton aggregations on the rest of the ecosystem. Analyses indicate that the spatial scale and magnitude of biological hotspots in the Gulf of Maine depend on the location and time of the year. Results also show that these hotspots change over time in response to both short-term oceanographic processes and long-term climatic cycles. Finally, the new metric presented here facilitates the spatial comparison between different trophic levels, thus allowing interdisciplinary ecosystem-wide studies.

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