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Spatio-temporal Ecology, Habitat Use And Population Size Of Brown Bears (ursus Arctos) In Yusufeli, TurkeyAmbarli, Huseyin 01 September 2012 (has links) (PDF)
Brown bear is the largest mammal in Turkey and its main distribution lies in the Black Sea and Eastern Anatolia Regions. Its basic ecology is almost unknown in Turkey, except for a limited number of studies. This study aims to determine the spatio-temporal ecology and habitat use of brown bears in the Kaç / kar Mountains, and to estimate their population size in the Ö / zgü / ven Valley and Yusufeli, both firsts for Turkey. The study area is primarily covered with conifer and oak stands, but sparse mixed shrubland occurs in the Mediterranean climate influenced lower parts. GPS-GSM telemetry on seven captured bears (5 males and 2 females) was the main field technique used in this study. Other methods include monitoring via camera trapping, visual direct observations, and counting cubs of the year. Bears were fitted with GPS-GSM collars and tracked for 3 to 603 days. Mean home range size (HRS) was calculated by 95% kernel and MCP estimators for three different samples sizes.95% MCP for all positions produced a home range size of 19.91 ± / 8.89 sq. km. for females, and 130.68 ± / 102.95 sq.km. for males. On average, males and females move at rates of 199 m/h and 129 m/h, respectively. Males hibernate around 140 days whereas females around 150 days and at lower elevations than males. According to camera trapping results, bears are generally active at twilight whereas activity data loggers produced disparate results for tracked bears. Resting patterns showed that bears may also rest at midnight. Estimated population density per 100 km2. is 24.50 ± / 1.74 individual using the Fcub method and 23.85 ± / 2.51 using the mark&ndash / resight method. Captured bears indicated nonrandom distribution on habitat use and selected productive croplands and shrublands than other types of vegetation. Brown bear HRS in the Kaç / kars is smaller than reported from most countries. The large female-male HRS difference is probably due to polygamous mating system, sexual dimorphism, hard mast availability, high population density, and female&rsquo / s habitat exclusivity as a result of high tolerance by the local people in contrast with most northern countries. Although primary productivity is used to explain high population density and small HRS in other countries, the low productivity in the study area cannot explain the observed density and HRS difference. These findings will construct a scientific basis for brown bear management and conservation in Turkey.
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Molecular Electronics : A Theoretical Study of Electronic Structure of Bulk and InterfacesUnge, Mikael January 2006 (has links)
This thesis deals with theoretical studies of the electronic structure of molecules used in the context of molecular electronics. Both studies with model Hamiltonians and first principle calculations have been performed. The materials studied include molecular crystals of pentacene and DNA, which are used as active material in field-effect transistors and as tentative molecular wires, respectively. The molecular magnet compound TCNE and surface modification by means of chemisorption of TDAE on gold are also studied. Molecular crystals of pentacene are reported to have the highest field-effect mobility values for organic thin film field-effect transistors. The conduction process in field-effect transistors applications occurs in a single layer of the molecular crystal. Hence, in studies of transport properties molecular crystals of pentacene can be considered as a two dimensional system. An open question of these system is if the charge transport is bandlike or if as a result of disorder is a hopping process. We address this question in two of the included papers, paper I and paper II. The conducting properties of DNA are of interest for a broad scientific community. Biologist for understanding of oxidatively damaged DNA and physicist and the electronics community for use as a molecular wire. Some reports on the subject classifies DNA as a conductor while other report insulating behavior. The outcome of the investigations are heavily dependent on the type of DNA being studied, clearly there is a big difference between the natural and more or less random sequence in, e.g., λ-DNA and the highly ordered syntethic poly(G)-poly(C) DNA. It has been suggested that long-range correlation would yield delocalized states, i.e., bandlike transport, in natural DNA, especially in the human chromosome 22. In paper III we show that this is not the case. In general our results show that DNA containing an approximately equal amount of the four basis is an insulator in a static picture. An emerging research field is spintronics. In spintronic devices the spin of the charge carrier is as important as the charge. One can envision a device where spin alone is the carrier of information. In realizing spintronic devices, materials that are both magnetic and semiconducting are needed. Systems that exhibit both these properties are organic-based magnets. In paper IV the electronic structure of the molecular magnet compound TCNE is studied, both experimentally and theoretically. The injection of carriers from metal contacts to organic semiconductors is central to the performance of organic based devices. The interface between the metal contact and the organic material has been pointed out to be one of the device parameters that most significantly influences the device performance. This relates to the process of injection of charge carriers in to the organic material. In some contact and organic material combinations the energy barrier for charge injection can be very high. The barrier can be reduced by modify the interface dipole, this is achieved by a monolayer of adsorbed molecules at the interface. The molecule TDAE chemisorbed on gold is studied in paper V.
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Magneto-sensitive rubber in the audible frequency rangeBlom, Peter January 2006 (has links)
The dynamic behaviour in the audible frequency range of magneto-sensitive (MS) rubber is the focus of this thesis consisting of five papers A-E. Paper A presents results drawn from experiments on samples subjected to different constant shear strains over varying frequencies and magnetic fields. Main features observed are the existence of an amplitude dependence of the shear modulus referred to as the Fletcher-Gent effect for even small displacements, and the appearance of large MS effects. These results are subsequently used in Paper B and C to model two magneto-sensitive rubber isolators, serving to demonstrate how, effectively, by means of MS rubber, these can be readily improved. The first model calculates the transfer stiffness of a torsionally excited isolator, and the second one, the energy flow into the foundation for a bushing inserted between a vibrating mass and an infinite plate. In both examples, notable improvements in isolation are obtainable. Paper D presents a non-linear constitutive model of MS rubber in the audible frequency range. Characteristics inherent to magneto-sensitive rubber within this dynamic regime are defined: magnetic sensitivity, amplitude dependence, elasticity and viscoelasticity. A very good agreement with experimental values is obtained. In Paper E, the magneto-sensitive rubber bushing stiffness for varying degrees of magnetization is predicted by incorporating the non-linear magneto-sensitive audio frequency rubber model developed in Paper D, into an effective engineering formula for the torsional stiffness of a rubber bushing. The results predict, and clearly display, the possibility of controlling over a large range through the application of a magnetic field, the magneto-sensitive rubber bushing stiffness. / QC 20100816
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High Dynamic Range Video for Photometric Measurement of IlluminationUnger, Jonas, Gustavson, Stefan, Ynnerman, Anders January 2007 (has links)
We describe the design and implementation of a high dynamic range (HDR) imaging system capable of capturing RGB color images with a dynamic range of 10,000,000 : 1 at 25 frames per second. We use a highly programmable camera unit with high throughput A/D conversion, data processing and data output. HDR acquisition is performed by multiple exposures in a continuous rolling shutter progression over the sensor. All the different exposures for one particular row of pixels are acquired head to tail within the frame time, which means that the time disparity between exposures is minimal, the entire frame time can be used for light integration and the longest expo- sure is almost the entire frame time. The system is highly configurable, and trade-offs are possible between dynamic range, precision, number of exposures, image resolution and frame rate.
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A methodology for using bluetooth to measure real-time work zone travel timeZinner, Stephanie 13 November 2012 (has links)
This thesis seeks to provide guidance on the deployment of Bluetooth sensors for travel time measurement in work zone corridors. The investigation focuses on the detection characteristics of Class 1 and Class 2 Bluetooth devices, and how cultivating an understanding of these characteristics together with the effect of the sensor inquiry cycle length can suggest a more precise method of travel time measurement. This thesis also explores the range of detection location around a Bluetooth sensor in order to recommend a minimum corridor separation of Bluetooth sensors, and to ascertain the best method of Bluetooth travel time derivation. Finally, this thesis investigates these principles further through multiple side-fire deployments on the I-285 corridor in Atlanta, Georgia; as well as two deployments capturing several hours of active work zone travel time.
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An Analysis of Infant Bouncing at Different Spring FrequenciesHabib Perez, Olinda D 19 April 2011 (has links)
Infants explore environments through repetitive movements which are constrained or facilitated by the environmental context. The current studies analyzed how typically developing infants bounced in four environments that differed by system natural frequency. Four pre-walking infants (age 9.7 months ±1.8) were placed in four spring conditions with natural spring frequencies of 0.9, 1.15, 1.27 and 1.56 Hz. All infants bounced above the natural spring frequency in all conditions suggesting that they do not solely behave like a mass-spring system. Two patterns of bouncing adaptations were identified. Three infants regulated bounce frequency, while one infant regulated the percentage of time on the ground. When infants matched their bounce frequency to the natural frequency, trunk vertical displacement and joint ranges of motion decreased across conditions and demonstrated a shift from non-spring like to circular spring-like phase planes. Moderate to high correlations were found for inter- and intra-limb coordination. Conversely, when an infant regulated time on the ground, trunk vertical displacement and joint ranges of motion remained the same across conditions and inter- and intra-limb correlations were low to moderate. Phase planes remained circular spring-like for this infant. Asymmetrical loading patterns and decreasing vertical ground reaction forces were found in all infants suggesting that a timing component is always regulated. The difference in bouncing pattern may be indicative of different bouncing skill level.
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Potentiating the Oncolytic Efficacy of PoxvirusesKomar, Monica 26 July 2012 (has links)
Several wild-type poxviruses have emerged as potential oncolytic viruses (OVs), including orf virus (OrfV), and vaccinia virus (VV). Oncolytic VVs have been modified to include attenuating mutations that enhance their tumour selective nature, but these mutations also reduce overall viral fitness in cancer cells. Previous studies have shown that a VV (Western Reserve) with its E3L gene replaced with the E3L homologue from, OrfV (designated VV-E3LOrfV), maintained its ability to infect cells in vitro, but was attenuated compared to its parental VV in vivo. Our goal was to determine the safety and oncolytic potential VV-E3LOrfV, compared to wild type VV and other attenuated recombinants. VV-E3LOrfV, was unable to replicate to the same titers and was sensitive to IFN compared to its parental virus and other attenuated VVs in normal human fibroblast cells. The virus was also less pathogenic when administered in vivo. Viral replication, spread and cell killing, as measures of oncolytic potential in vitro, along with in vivo efficacy, were also observed..
The Parapoxvirus, OrfV has been shown to have a unique immune-stimulation profile, inducing a number of pro-inflammatory cytokines, as well as potently recruiting and activating a number of immune cells. Despite this unique profile, OrfV is limited in its ability to replicate and spread in human cancer cells. Various strategies were employed to enhance the oncolytic efficacy of wild-type OrfV. A transient transfection/infection screen was created to determine if any of the VV host-range genes (C7L, K1L, E3L or K3L) would augment OrfV oncolysis. Combination therapy, including the use of microtubule targeting agents, Viral Sensitizer (VSe) compounds and the addition of soluble VV B18R gene product were employed to see if they also enhance OrfV efficacy. Unfortunately, none of the strategies mentioned were able to enhance OrfV.
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Can Landscape Composition Predict Movement Patterns and Site Occupancy by Blanding's Turtles?: A Multiple Scale Study in Québec, CanadaFortin, Gabrielle 07 December 2012 (has links)
As habitat loss and fragmentation are major causes of decline in animal species, studying habitat requirements in these species is a key component of their recovery. I investigated the relationship between landscape composition and habitat use of Blanding’s turtles, Emydoidea blandingii, a freshwater turtle threatened by habitat loss and road mortality on most of its Canadian range. In 2010, I conducted a radio-telemetry survey of 44 Blanding’s turtles in southern Québec, Canada, and modelled their home range size from land cover proportions measured at many spatial scales. I also used data from a visual survey conducted in 2008 and 2009 to model wetland occupancy of the species at the landscape scale. Home range size of the Blanding’s turtle was significantly correlated to landscape composition, and the proportions of agriculture, open water and anthropogenic lands had the strongest relationships with home range size. However, those relationships were weak and the models were unable to predict home range size accurately. At the landscape scale, land cover and road density poorly predicted probability of occurrence, and Blanding’s turtles occupied wetlands in both disturbed and natural sites. Management of the species should focus on protecting sites of occurrence with high wetland density, low road density, and sufficient suitable habitat to cover their seasonal movement patterns.
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Ecological Responses to Threats in an Evolutionary Context: Bacterial Responses to Antibiotics and Butterfly Species’ Responses to Climate ChangeFitzsimmons, James 20 February 2013 (has links)
Humans are generally having a strong, widespread, and negative impact on nature. Given the many ways we are impacting nature and the many ways nature is responding, it is useful to study responses in an integrative context. My thesis is focused largely (two out of the three data chapters) on butterfly species’ range shifts consistent with modern climate change in Canada. I employed a macroecological approach to my research, drawing on methods and findings from evolutionary biology, phylogenetics, conservation biology, and natural history. I answered three main research questions. First, is there a trade-off between population growth rate (rmax) and carrying capacity (K) at the mutation scale (Chapter 2)? I found rmax and K to not trade off, but in fact to positively co-vary at the mutation scale. This suggests trade-offs between these traits only emerge after selection removes mutants with low resource acquisition rates (i.e., unhealthy genotypes), revealing trade-offs between remaining genotypes with varied resource allocation strategies. Second, did butterfly species shift their northern range boundaries northward over the 1900s, consistent with climate warming (Chapter 3)? Leading a team of collaborators, we found that most butterfly species’ northern range boundaries did indeed shift northward over the 1900s. But range shift rates were slower than those documented in the literature for more recent time periods, likely reflecting the weaker warming experienced in the time period of my study. Third, were species’ rates of range shift related to their phylogeny (Chapter 3) or traits (Chapter 4)? I found no compelling relationships between rates of range shift and phylogeny or traits. If certain traits make some species more successful at northern boundary range expansion than others, their effect was not strong enough to emerge from the background noise inherent in the broad scale data set I used.
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Evolution of Local Adaptation During Plant Invasion: Purple Loosestrife (Lythrum salicaria – Lythraceae) in Eastern North AmericaColautti, Robert I. 06 August 2010 (has links)
Biological invasions provide opportunities to study evolutionary processes occurring during contemporary time scales. Here, I combine a literature review of common garden studies of invasive plant species, with field and glasshouse experiments on populations of the outcrossing, perennial, wetland invader Lythrum salicaria (purple loosestrife - Lythraceae), to investigate the evolutionary genetics of local adaptation in reproductive and life-history traits.
A review of 32 common garden studies of 28 introduced species identified previously unrecognized latitudinal clines in phenotypic traits in both native and introduced populations. To obtain direct evidence for clinal variation and local adaptation, I investigated populations of L. salicaria sampled along a latitudinal gradient of growing season length in eastern North America. Controlled pollinations of plants from 12 populations provided no evidence for the breakdown of self-incompatibility to self-compatibility towards the northern range limit. However, a quantitative genetic experiment involving 20 populations revealed latitudinal clines in population mean, variance and skew for days to flower and vegetative size. Broad-sense estimates of genetic variance were significant for most traits; however, strong inter-correlations among traits suggested that fitness trade-offs have constrained population divergence. The observed clines supported a model of selection for early flowering in northern populations constrained by a trade-off between age and size at flowering.
A comparison of variance-covariance matrices of family and population means (G and D, respectively) of life-history traits demonstrated that populations have evolved in response to selection under genetic constraints, rather than through neutral processes. A reciprocal transplant experiment involving six populations and three common gardens spanning the latitudinal range provided direct evidence for local adaptation in flowering phenology. Populations maintained the same rank-order for time to flowering and vegetative size at each site, and southern populations had the highest fecundity at the southern site but the lowest at the northern site. Finally, a phenotypic selection analysis in each common garden involving 61 F2 families of crosses between a northern × southern populations confirmed that selection favours earlier flowering in northern populations. These results demonstrate that natural selection on reproductive phenology has accompanied the invasive spread of L. salicaria in eastern N. America.
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