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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.
51

Conservation Genetics of Black Bears in Arizona and Northern Mexico

Varas-Nelson, Angela Cora January 2010 (has links)
Because American black bears (Ursus americanus) are an important game species in Arizona and are endangered in México, an understanding of the population structure, gene flow, and connectivity are important for effective management. Black bears inhabit coniferous and broadleaf deciduous woodlands in southern Arizona and northern México, usually in sky islands (sky islands are mountains that rise from the desert and are isolated from each other). Because a single sky island is too small to support a viable bear population, black bears move through desert lowlands to reach other sky islands. My objective was to assess genetic structure, connectivity, and conservation implications for sky island black bears in southern Arizona and northern México. I addresses 4 components of bear ecology and genetics: a literature review of genetic information available for black bears in North America; the use of 2 mitochondrial DNA genes (Control Region and ATP synthase protein 8) to study the phylogenetic relationship of black bears from the sky islands of southern Arizona and northern México relative to all North America; the use of 10 microsatellite loci to detect the current genetic structure of black bears in the sky islands in Arizona and northern México; and the use of noninvasive samples collected from the field to determine bear density and population size for black bear in Sierra San Luis, Sonora, México. These studies provide information that can be used by biologists, land managers, and others to assist in the conservation of black bears and their habitat.
52

Applications of learning theory to human-bear conflict: the efficacy of aversive conditioning and conditioned taste aversion

Homstol, Lori Unknown Date
No description available.
53

Applications of learning theory to human-bear conflict: the efficacy of aversive conditioning and conditioned taste aversion

Homstol, Lori 06 1900 (has links)
I tested the efficacy of aversive conditioning (AC) and conditioned taste aversion (CTA) on American black bears (Ursus americanus) in Whistler, British Columbia. Black bears subjected to 3-5 day AC programs responded by increasing their wariness toward humans, while control bears habituated. Bears were located closer to human developments during daylight hours after AC treatments. However, there was no difference in the proportion of utilization distribution that overlapped with developed areas in control or AC-treated bears. CTA may be effective for managing specific attractants that are difficult to secure from bears. Bears appeared to distinguish between baits treated with thiabendazole and baits that were not treated, but by using a protocol that caused severe illness and left the source of illness in doubt, I induced taste aversions to apples in 4 bears. Using both AC and CTA may help wildlife managers mitigate human-wildlife conflicts non-lethally more effectively. / Ecology
54

Diverzita kryptosporidií volně žijících psovitých a medvědovitých šelem

KELLNEROVÁ, Klára January 2018 (has links)
The study was focused on study of diversity of Cryptosporidium spp. in wild canines and bears in the Czech Republic, Slovak Republic, Poland and Romania. A total of 359 faecal samples were collected from 179 red foxes (Vulpes vulpes), 83 grey wolves (Canis lupis), 63 brown bears (Ursus arctos) and 34 jackals (Canis aureus). Faecal samples were screened for Cryptosporidium by microscopy and PCR/sequencing. Phylogenetic analysis of small-subunit rRNA, actin and 60-kDa glycoprotein sequences revealed the presence of C. tyzzeri, C. andersoni in red foxes, C. canis and C. ubiquitum in gray wolves and C. galli in a brown bear and a red fox. Subtyping of C. ubiquitum and C. tyzzeri isolate by sequence analysis of the 60-kDa glycoprotein gene showed that isolates belonged to the XIId and IXa subtype family, respectively. Detection of host-non-specific cryptosporidia, except C. canic and C. ubiquitum, in wild canine and bears shows rather a food preference of screened carnivors than on an active infection.
55

Two New Species of Tardigrada From Moss Cushions (Grimmia sp.) in a Xerothermic Habitat in Northeast Tennessee (USA, North America), With the First Identification of Males in the genus Viridiscus

Nelson, Diane R., Fletcher, Rebecca Adkins, Guidetti, Roberto, Roszkowska, Milena, Grobys, Daria, Kaczmarek, Lukasz 23 November 2020 (has links)
Background. The phylum Tardigrada consists of over 1,300 species that inhabit terrestrial, freshwater and marine environments throughout the world. In terrestrial habitats they live primarily in mosses, lichens, leaf litter and soil, whereas tardigrades in freshwater and marine environments are mainly found in sediments and on aquatic plants. More than 65 species have been previously reported in the state of Tennessee, USA. Methods. Tardigrades present in moss cushions (Grimmia sp.) collected from a xerothermic habitat on the East Tennessee State University campus, Johnson City, TN, USA, were extracted, mounted on slides, identified, and counted. Additional samples of fresh dried moss were used for integrative analyses, including morphological analysis with phase contrast (PCM) and scanning electron microscopy (SEM), as well as molecular analyses of COI, 18S rRNA, 28S rRNA, and ITS-2 of the Macrobiotus and Milnesium species. Results. Five species were found, including two species new to science: Viridiscus miraviridis sp. nov. and Macrobiotus basiatus sp. nov. Viridiscus miraviridis sp. nov. differs from other members of the genus mainly by having a different type of dorsal cuticle and some other, more subtle, morphometric characters. In addition to the two new species, Viridiscus perviridis and Viridiscus viridissimus were present, and males of Vir. viridissimus were found for the first time, the first record of males in the genus Viridiscus. Macrobiotus basiatus sp. nov. is most similar to Macrobiotus nelsonae, but it differs from Mac. nelsonae mainly by the stylet supports being situated in a more anterior position, shorter and narrower egg processes, and a smaller number of areoles around the egg processes. Moreover, the identification of Milnesium inceptum was confirmed as the first record for the USA by analysis of COI.
56

A Global Biodiversity Estimate of a Poorly Known Taxon: phylum Tardigrada

Bartels, Paul J., Apodaca, J. J., Mora, Camilo, Nelson, Diane R. 01 December 2016 (has links)
Although many estimates of species numbers have been attempted using various techniques, many smaller phyla remain poorly known without such estimates. For most of these it is unclear if they are species-poor or just poorly studied. The phylum Tardigrada is one of these phyla. Specialists have created a regularly updated checklist for the known tardigrade species, which as of 15 July 2013 listed 1190 taxa (species and subspecies). Of these, 1008 are limnoterrestrial and 182 are marine. These were the most up-to-date data at the time of our analysis. As species accumulation curves show little sign of levelling out, they do not provide a useful tool for estimating global tardigrade diversity from existing species numbers. A new technique has recently been developed that uses the more complete knowledge of higher taxonomic levels to estimate the asymptotic number of species. We applied this technique to limnoterrestrial and marine tardigrades. We estimate that the global total for limnoterrestrial tardigrades is 1145 (upper 95% CI = 2101), and the global total for marine tardigrades is 936 (upper 95% CI = 1803). This yields 87% completeness for our knowledge of limnoterrestrial tardigrades, and only 19% completeness for our knowledge of marine tardigrades. Thus, although many more marine species remain to be discovered, it appears that tardigrades are both poorly studied and relatively species poor.
57

The Zoogeography of Marine Tardigrada

Kaczmarek, Lukasz, Bartels, Paul J., Roszkowska, Milena, Nelson, Diane R. 01 January 2015 (has links)
This monograph describes the global records of marine water bears (Phylum Tardigrada). We provide a comprehensive list of marine tardigrades recorded from around the world, providing an up-to-date taxonomy and a complete bibliography accompanied by geographic co-ordinates, habitat, substrate and biogeographic comments. A link is provided to an on-line interactive map where all occurrences for each species are shown. In total we list 197 taxa and their 2240 records from 39 oceans and seas and 18 Major Fishing Areas (FAO). It is hoped this work will serve as a reference point and background for further zoogeographic and taxonomic studies on marine tardigrades.
58

Ramazzottius belubellus, a new species of Tardigrada (Eutardigrada: Parachela: Hypsibiidae) from the Great Smoky Mountains National Park (North Carolina, U.S.A.)

Bartels, Paul J., Nelson, Diane R., Kaczmarek, Łukasz, Michalczyk, Łukasz 08 April 2011 (has links)
A new species, Ramazzottius belubellus, is described from a single lichen sample collected in the Great Smoky Mountains National Park in western North Carolina, U.S.A. The new species is easily distinguishable from all other members of the genus Ramazzottius by the presence of long dorsal, sharp triangular spines not arranged in transverse bands as opposed to small tubercles arranged in bands, or a thin reticulum, or a smooth cuticle present in all other described species of the genus. The new species could be confused with R. baumanni but differs from it by the presence of sharp triangular spines on the dorsal side of the body instead of flat, hemispherical tubercles.
59

An Updated Species List for “Smoky Bears”: Tardigrades of the Great Smoky Mountains National Park, USA

Bartels, Paul J., Nelson, Diane R., Kaczmarek, Lukasz 01 June 2021 (has links)
One of the largest inventories of tardigrades ever conducted occurred from 2000 2010 in the Great Smoky Mountains National Park, USA. Over 16,000 specimens were catalogued, 85 species were identified, 11 species new to science were described, and 16 other possible new species await further study. More than 20 papers have resulted from the GSMNP tardigrade inventory, making the Smokies the most thoroughly studied area in North America for tardigrades. Several species lists have been published over this 20-year period, but many taxonomic revisions and new identifications have led to significant changes to the list. Biogeographical studies citing species records from earlier studies could yield serious errors. Here we update the species list from the Smokies to accommodate the many recent changes in tardigrade taxonomy, we re-Analyze some species in light of delineations of cryptic species groups that have occurred recently via integrative taxonomy, and we provide a table of all synonyms that have been used in previous publications. We also make available, for the first time, the Smokies tardigrade database, complete with all locations, elevations, and substrates.
60

Marine Tardigrades of the Bahamas With the Description of Two New Species and Updated Keys to the Species of Anisonyches and Archechiniscus

Bartels, Paul J., Fontoura, Paulo, Nelson, Diane R. 20 May 2018 (has links)
This is the first survey of subtidal marine tardigrades from the Bahamas, and we compare our results with earlier studies of Bahamian intertidal habitats. In 2011 and 2014 we collected 60 subtidal sand samples from Bimini, the Berry Islands, New Providence, Eleuthera, and the Exumas. We found 11 species only one of which, Dipodarctus subterraneus (Renaud- Debyser, 1959), had been found in the previous intertidal Bahamian collections. Thus, 10 species are new records for the Bahamas, and four of these are new to science. We describe two of the new species (Archechiniscus bahamensis sp. nov. and Anisonyches eleutherensis sp. nov.). Additional material is needed for a conclusive identification of the undescribed species of Batillipes and Florarctus. Based on examination of the holotype of Anisonyches diakidius Pollock, 1975, we redescribe this species and give an emended diagnosis of the genus and the species. We also provide new keys to the spe-cies in the genera Archechiniscus and Anisonyches. A Chao2 species richness estimate indicated that our sampling effort was extensive and probably recovered most common species. Correlations of abundance and diversity indices with regard to depth, distance to nearest shore, and sediment grain size were not significant.

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