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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.
11

Tracking collar and infrastructure for leopard research

Warnich, Dirk J. 12 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: This project targeted the development of a new tracking collar, trap telemetry system and supporting infrastructure, to aid researchers from the Cape Leopard Trust. Previously used collar products had all proven insu cient in some capacity and remote monitoring of trap sites was also required. Tracking collars are used to identify the movement patterns of the leopards and through the resulting research, assist in protecting this threatened species. In the development of the tracking collar and trap telemetry system, a high level system design was rst formulated, identifying major components that would be required. Alternative methods for implementation were then considered and the most optimal chosen. Two di erent modes of communication with the collar were envisioned and designed for. These would be used to transmit logged coordinates obtained from a GPS receiver back to researchers. A VHF terrestrial radio link was investigated, but an Iridium Satellite based solution was ultimately selected. An Iridium Satellite communications system was also used for transfer of trap state data. Ultimately, a working trap telemetry system was delivered for use by researchers. The tracking collar system had progressed to a working prototype, requiring miniaturisation and packaging before deployment. A possible packaging solution was also identi ed. The trap telemetry system, although displaying certain de ciencies, provided a capability previously unavailable to researchers. With further development, there is potential for the tracking collar to provide accurate satellite tracking and communications in a mass and price combination not previously available. / AFRIKAANSE OPSOMMING: Hierdie projek het as doel die ontwikkeling van 'n nuwe opsporingshalsband, 'n lokval telemetriese stelsel en die nodige ondersteunende infrastruktuur daarvoor. As hulpmiddels vir navorsers van Cape Leopard Trust. Geen van die halsband produkte wat tot nou toe gebruik is, het voldoen aan al die nodige behoeftes nie, en dit was ook nodig om die lokvalterreine van 'n afstand te kan monitor. Die opsporingshalsbande word gebruik om die bewegingspatrone van luiperds vas te stel en die navorsing wat daarop volg, help dat 'n bedreigde spesie bewaar word. Die ontwikkeling van die opsporingshalsband en lokval telemetriese stelsel het begin met die formulering van 'n ho evlak stelselontwerp waarin die hoofkomponente wat benodig sou wees ge denti seer is. Alternatiewe metodes van bewerkstelling is daarna oorweeg en die optimale hiervan is gekies. Twee verskillende metodes van kommunikasie met die halsband is voorgestel en ontwerp. Hierdie sou gebruik word om die vasgelegte koordinate wat van 'n GPS ontvanger verkry is, na navorsers terug te versend. 'n Terrestriale radioverbinding is ondersoek, maar 'n Iridium Satelliet-baseerde oplossing is uiteindelik verkies. 'n Iridium Satelliet kommunikasie stelsel is ook gebruik vir die oordrag van data aangaande die lokvaltoestand. Uitendelik is 'n werkende lokval telemetriese stelsel gelewer vir dir gebruik van navorsers. Die opsporingshalsband stelsel was nou 'n werkende prototipe, wat slegs verklein en toepaslik verpak moes word voor dit in gebruik geneem kon word. 'n Moontlike oplossing tot die verpakkingsprobleem is ook identi seer. Die lokval telemetriese stelsel, hoewel dit steeds tekorte toon, voorsien die navorsers van voorheen onbekombare inligting. Met verder ontwikkeling is daar potensiaal vir die opsporingshalsband om akkurate satellietopsporing en kommunikasie te voorsien in 'n kombinasie van laer massa, sowel as prys, soos nog nooit voorheen beskikbaar nie.
12

How elephants utilize a miombo-wetland ecosystem in Ugalla landscape, Western Tanzania

Kalumanga, Elikana January 2015 (has links)
African elephants are ‘keystone’ species with respect to biodiversity conservation in Africa since they maintain habitats that support several animal communities by changing vegetation structure through foraging and by dispersing seeds between landscapes. Elephants are also ‘flagship’ species because, given their impressive size, they can make people sympathetic and stimulate local and international concerns for their protection. Economically, elephants contribute to national revenues as tourists are willing to pay to watch them. Despite all these factors, little is known however about elephant movement and how they utilize resources, especially in miombo-wetland ecosystems. This thesis investigates how elephants utilize resources in a miombo-wetland ecosystem in the Ugalla landscape of Western Tanzania over different protected areas containing different resource users. Using Global Positioning System (GPS) collars fitted to six elephants, it was observed that some elephant families are not confined in one protected area in the Ugalla landscape. Rather, they moved readily between different protected areas. Elephant movements were restricted to areas near the rivers, especially the Ugalla River, during the dry season and were dispersed widely during the wet season. As they move, elephants in the miombo woodlands of Ugalla selected the most abundant woody plants for browsing. Common to many woody plants, the browsed plants were short of mineral nutrients (e.g., sodium, calcium). Elephants obtained additional minerals by eating soils from certain termite mounds. Soils from termite mounds are richer in mineral elements (e.g., sodium, calcium, iron) compared to soils from the surrounding flood plain or compared to the browsed plants. However, the recorded termite mounds from which elephants eat soils were not evenly distributed in the landscape but confined mainly to the flood plains in the Ugalla Game Reserve. The Ugalla River, which is the main source of water for the elephants and other animals and also supports fishing activities by the local people in Ugalla during the dry seasons, is infested by the water hyacinth (Eichhornia crassipes). Such infestation potentially limits access to these precious surface water supplies. In addition at the regional level, the Ugalla River is among the major rivers that flow into the Lake Tanganyika which is shared by the countries of Tanzania, Burundi, Democratic Republic of Congo and Zambia. Thus, the spread of water hyacinth if left unchecked threatens to impact Lake Tanganyika, affecting many countries and ecosystem services. This thesis highlights that sustainable conservation of biodiversity in different protected areas in the Ugalla landscape requires an integrated management approach that will embrace conservation of different interrelated landscape resources required by both wildlife and the rural poor populations for their livelihoods. Regular coordinated wildlife anti-poaching patrols should be initiated across the entire Ugalla landscape because the elephants, among other wildlife, utilize different protected areas in Ugalla. Local communities should also be engaged in conservation initiatives (e.g., controlling the spread of the water hyacinth) as these directly impact local livelihoods. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 2: Manuscript. Paper 3: Manuscript. Paper 4: Manuscript.</p> / INTEGRATED NATURAL RESOURCES MANAGEMENT
13

A utilização de instrumentos derivativos na gestão de riscos associada à contratação de energia elétrica por grandes consumidores

Honorato, Elaine Fridman 16 June 2010 (has links)
Submitted by Cristiane Shirayama (cristiane.shirayama@fgv.br) on 2011-05-24T13:09:28Z No. of bitstreams: 1 61080100065.pdf: 2231348 bytes, checksum: 235b121ee6f62ddc94f7bcdc52256691 (MD5) / Approved for entry into archive by Gisele Isaura Hannickel(gisele.hannickel@fgv.br) on 2011-05-24T13:42:08Z (GMT) No. of bitstreams: 1 61080100065.pdf: 2231348 bytes, checksum: 235b121ee6f62ddc94f7bcdc52256691 (MD5) / Approved for entry into archive by Gisele Isaura Hannickel(gisele.hannickel@fgv.br) on 2011-05-24T13:42:43Z (GMT) No. of bitstreams: 1 61080100065.pdf: 2231348 bytes, checksum: 235b121ee6f62ddc94f7bcdc52256691 (MD5) / Made available in DSpace on 2011-05-24T13:43:07Z (GMT). No. of bitstreams: 1 61080100065.pdf: 2231348 bytes, checksum: 235b121ee6f62ddc94f7bcdc52256691 (MD5) Previous issue date: 2010-06-16 / No Brasil, os contratos firmados entre geradores e grandes consumidores são registrados na Câmara de Comercialização de Energia que é responsável por contabilizar as diferenças entre o consumo contratado e o consumo verificado. Essas diferenças são negociadas ao Preço de Liquidação das Diferenças, o PLD. Este preço apresenta, como uma de suas principais características, o fato de ser volátil, pois está relacionado ao volume de água disponível para a geração de energia elétrica, o que é algo dependente das condições meteorológicas (no Brasil aproximadamente 80% da geração é proveniente de fontes hidráulicas).
14

White collar revisited - millsovská teorie vlivu byrokratizace na sociální a ekonomický vývoj západních společností. / White collar revisited - Millsean theory on impact of bureaucratization on social and economic development of western societies

Hampl, Petr January 2015 (has links)
The first part of this thesis sums up ideas, which the author had published in his essays. These ideas are mostly focused on the relationship between the class structure of current western societies and economic policy preferred by the governments. The next part is dedicated to Charles Wright Mills, his sociological method, his contribution to sociology of 50th as well as his heritage for current sociological thinking. Three idea streams, which can be used for supplementing Mills' point of view, are explained: public choice economy (mainly its version of Gordon Tullock), new class theory and theory of business innovation. New typology of business innovation is developed in this part. The core of this thesis consist in discussion of Mills' propositions about the growth of bureaucratic organizations, birth of white collars as a massive social class and its impact on social structure, economic development and political development of western societies. Mills conclusions are looked on in the light of socioeconomic development during 60 years since the first publishing of White collar. They are also compared with key finding of idea streams mentioned above. Theory of impact of growth of big bureaucracy on economic and political development is formulated that specifies and supplement Mills' theory. The...
15

Une analyse de la connectivité fonctionnelle du paysage : Etude des déplacements et des flux de gènes chez un mustélidé forestier, la Martre des pins (Martes martes) / Analysis of functional landscape connectivity : Study of movements and genes flow of a forest mustelid, the Pine marten (Martes martes)

Bardonnet, Clara 17 December 2015 (has links)
Les modifications du paysage engendrées par les activités humaines sont une des causes majeures du déclin de la biodiversité. En générant une perte de la connectivité fonctionnelle du paysage, elles limitent les déplacements des individus et entraînent la rupture des flux de gènes, processus clés dans le maintien et la persistance des populations. Cependant, le lien entre ces processus et la structure du paysage est encore mal compris. Dans ce contexte, nous avons conduit une étude sur la Martre des pins, une espèce a priori forestière, bien que capable de s’installer durablement dans des paysages fragmentés. A partir de l’analyse de la variabilité génétique de groupes échantillonnées sur 13 sites forestiers à l’échelle de la région Champagne-Ardenne, et du suivi des déplacements d’individus à fine échelle, en milieu continu et fragmenté, nous avons estimé la résistance du paysage aux différents déplacements, c’est-à-dire dans quelle mesure ceux-ci sont freinés ou facilités par les éléments du paysage. Nous avons mis en évidence que les déplacements sont freinés, d’une part par la présence d’une large plaine agricole, et d’autre part, par certaines infrastructures de transport. Nous avons également mis en évidence que les déplacements des martres entre les taches d’habitats sont facilités par la présence de haies et que la hauteur du couvert végétal des habitats non boisés pourrait jouer un rôle dans ces déplacements. Cette étude apporte d’importantes connaissances sur l’écologie des déplacements de la Martre des pins et souligne la nécessité de la prise en compte de la réponse des organismes dans l’établissement des futurs réseaux écologiques. / Landscape changes, generated by anthropogenic activities, are widely recognised as one of the main causes of global biodiversity decline. Leading to a loss of functional landscape connectivity, they disrupt movements and gene flow which play a primordial role for the persistence of populations. However, the relationship between these processes and landscape structure remains unclear. In this context, we studied landscape connectivity in European pine marten, a forest species present in fragmented landscapes. We evaluated landscape resistance, i.e. how landscape features impede or facilitate movements and gene flow, analysing genetic variability of groups sampled in 13 forest sites of the Champagne-Ardenne regional area, and studying individual fine-scale movements in both continuous and fragmented areas. We showed that intensive agricultural plain and certain linear infrastructures could impede movements. In addition, we showed that hedgerows facilitate movements between forest patches and we suggested that vegetation height of open habitats could play a role for these movements. This study provides important insights on movement ecology of the European pine marten and underlines the need to take into account responses of organisms in the establishment of ecological networks.
16

Niche segregation by cheetah (Acinonyx jubatus) as a mechanism for co-existence with lion (Panthera leo) and spotted hyaena (Crocuta crocuta)

Broekhuis, Femke January 2012 (has links)
Intraguild competition and predation have been recognised as important ecological factors influencing the population dynamics of carnivores. The effects of these interactions are often asymmetrical due to a size-related dominancy hierarchy. However, it has been suggested that competitively subordinate carnivores can minimise the costs of predation and competition through spatial and temporal avoidance. Here I investigate the ecological and behavioural mechanisms by which cheetahs (Acinonyx jubatus) coexist with competitively stronger lions (Panthera leo) and spotted hyaenas (Crocuta crocuta). Fieldwork was carried out in the Okavango Delta, northern Botswana, between October 2008 and August 2011. A total of 20 Global Positioning System (GPS) radio-collars were fitted on all known cheetahs (n=6), lion prides (n=5) and spotted hyaena clans (n=6) in the study area (approx. 3 000 km<sup>2</sup>). Pre-programmed radio-collars recorded locations and activity continuously for each individual and these data were complemented with direct behavioural observations. Cheetah data were analysed with respect to the temporal and spatial likelihood of encountering lions and spotted hyaenas. Results suggest that the response to the risks posed by other predators is species-specific, habitat-specific and dependent on the immediacy of the risk. Resource partitioning was not the main mechanism for coexistence as cheetahs overlapped extensively with lions and spotted hyaenas in time, space and habitat use. Instead, cheetahs adjusted their spatial distribution in response to immediate risks or adapted their habitat use depending on their vulnerability (e.g. behaviours such as feeding or with differing levels of moonlight at night). In general, cheetah temporal and spatial distribution is a hierarchal process, firstly driven by resource acquisition and thereafter fine-tuned by predator avoidance. In addition, habitat heterogeneity seemed to be key in facilitating coexistence. Understanding the behavioural mechanisms that interacting apex predators adopt to regulate these negative interactions could be crucial to carnivore conservation, especially as human-related habitat loss is forcing species into ever smaller areas.
17

La série Mad Men : une élégie de la révolution créative dans les années soixante

Traistaru, Felicia 08 1900 (has links)
No description available.

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