Cytogenetic Evidence for the Specific Distinction of an Alaskan Marmot, \u3ci\u3eMarmota broweri\u3c/i\u3e Hall and Gilmore (Mammalia: Sciuridae)

Cytogenetic studies based upon somatic cells (bone marrow) have disclosed that the marmot hitherto designated Marmota caligata broweri Hall and Gilmore, occurring in the Brooks Range of Arctic Alaska, differs from M. c. caligata (Eschscholtz) in number of chromosomes (2n=36 as compared with 2n=42 in M. caligata) and in proportions of chromosomal types. Typical karyograms for the two species are presented. It is concluded that the Brooks Range marmot is specifically distinct from M. caligata, the applicable name being Marmota broweri Hall and Gilmore. Also determined were diploid chromosome numbers for two other Nearctic species of marmots, M. flaviventris (Audubon and Bachman), with 42, and M. olympus (Merriam), with 40. It is suggested that M. broweri survived the last (Wisconsin) glaciations in the amphi-Beringian refugium, and that its closest affinities may be with one of the Eurasian species of Marmota

Taxonomy and Zoogeography of \u3ci\u3eLemmus\u3c/i\u3e spp. (Rodentia: Arvicolinae), with Notes on Laboratory-Reared Lemmings

Lemmings of the genus Lemmus Link, 1795, have long attracted interest because of the high numerical densities attained at intervals by their populations. In earlier times, in northern Europe, such events seemed so remarkable as to be explained by some as a consequence of the animals\u27 having fallen from the sky (HaGSTROM 1749). During the last 25 years, lemmings have been the object of intensive ecological investigation in Eurasia and North America, although there has been no consensus concerning their taxonomic relationships. In 1959, a colony of brown lemmings from arctic Alaska was established in our laboratory, primarily to provide experimental animals for the study of zoonoses indigenous to arctic and subarctic North America. A colony of lemmings from Fennoscandia was similarly established in 1964. The lemmings proved to have advantages as laboratory animals, and at the same time the existence of the colonies permitted observations to be made on their biological characteristics and comparisons of chromosomes to be undertaken for the two forms and their hybrids. The results of these observations and comparisons, with a review of the zoogeography of Lemmus, are reported in the present paper

Taxonomy and Zoogeography of \u3ci\u3eLemmus\u3c/i\u3e spp. (Rodentia: Arvicolinae), with Notes on Laboratory-Reared Lemmings

Lemmings of the genus Lemmus Link, 1795, have long attracted interest because of the high numerical densities attained at intervals by their populations. In earlier times, in northern Europe, such events seemed so remarkable as to be explained by some as a consequence of the animals\u27 having fallen from the sky (HaGSTROM 1749). During the last 25 years, lemmings have been the object of intensive ecological investigation in Eurasia and North America, although there has been no consensus concerning their taxonomic relationships. In 1959, a colony of brown lemmings from arctic Alaska was established in our laboratory, primarily to provide experimental animals for the study of zoonoses indigenous to arctic and subarctic North America. A colony of lemmings from Fennoscandia was similarly established in 1964. The lemmings proved to have advantages as laboratory animals, and at the same time the existence of the colonies permitted observations to be made on their biological characteristics and comparisons of chromosomes to be undertaken for the two forms and their hybrids. The results of these observations and comparisons, with a review of the zoogeography of Lemmus, are reported in the present paper

Cytogenetic Evidence for the Specific Distinction of an Alaskan Marmot, \u3ci\u3eMarmota broweri\u3c/i\u3e Hall and Gilmore (Mammalia: Sciuridae)

Cytogenetic studies based upon somatic cells (bone marrow) have disclosed that the marmot hitherto designated Marmota caligata broweri Hall and Gilmore, occurring in the Brooks Range of Arctic Alaska, differs from M. c. caligata (Eschscholtz) in number of chromosomes (2n=36 as compared with 2n=42 in M. caligata) and in proportions of chromosomal types. Typical karyograms for the two species are presented. It is concluded that the Brooks Range marmot is specifically distinct from M. caligata, the applicable name being Marmota broweri Hall and Gilmore. Also determined were diploid chromosome numbers for two other Nearctic species of marmots, M. flaviventris (Audubon and Bachman), with 42, and M. olympus (Merriam), with 40. It is suggested that M. broweri survived the last (Wisconsin) glaciations in the amphi-Beringian refugium, and that its closest affinities may be with one of the Eurasian species of Marmota

Studies on the Helminth Fauna of Alaska. XXVII. The Occurrence of Larvae of \u3ci\u3eTrichinella spiralis\u3c/i\u3e in Alaskan Mammals

In 1948 much interest in trichinosis in arctic regions was aroused, particularly by the findings of Thorborg et al. (1948), who investigated serious outbreaks occurring among the Eskimo of West Greenland during 1947. Consequently, with the founding of the Arctic Health Research Center in the autumn of 1948, a study of trichinosis in Alaska was the first project to be initiated by the Zoonotic Disease Section (formerly Animal-borne Disease Section) of this Center. Field work was begun in January, 1949, and a preliminary note on trichinosis in Alaskan mammals was published by Brandly and Rausch (1950). The subject of trichinosis in arctic regions was reviewed by Connell (1949). The survey to determine the prevalence of T. spiralis in mammals in Alaska was terminated in the spring of 1953; this paper reports the results of this work

Indicators of Resiliency Among Urban Elementary School Students At-Risk

This study was designed to investigate the phenomenon of resiliency among urban elementary school students in an at-risk environment. In contrast with previous studies narrowly focused upon the identification of risk factors, this study utilized a phenomenological qualitative approach to investigate indicators of resiliency from both individual and contextual perspectives. The narrative descriptions of 25 elementary school students in an at-risk environment were analyzed. The results indicated that the participants had strong individual and contextual resiliency indicators through the fifth grade despite being educated in a school district with almost a 60% drop-out rate before high school graduation

Toxicology Studies of Lewisite and Sulfur Mustard Agents: Genetic Toxicity of Lewisite (L) In Chinese Hamster Ovary Cells

The cytotoxic clastogenic and mutagenic effects of the arsenic containing vesicant, Lewisite (L) [dichloro(2-chlorovinyl) arsine], have been investigated using Chinese hamster ovary cells. One hour exposures to Lewisite were cytotoxic in uM amounts. The cell survival response yields a D37 of 0.6 uM and an extrapolation number of 2.5. The mutagenic response at the hypoxantnine-guanine phosporibosyl transferase (HGPRT) locus was sporadic and not significantly greater than control values when cells were exposed over a range of 0.125 to2.0 uM. Sister chromatid exchange (SCE) induction, a measure of chromosomal rearrangement, was weakly positive over a range of 0.25 to 1.0 uM but the values were not significantly greater than the control response. Chromosomal aberrations were induced at 0.75 and 1.0 UMin one experiment and 0.5 and 0.75 uM in another experiment. The Induced values were significantly greater than the control values. Lewisite appears to be cytotoxic and clastogenic in our investigations but SCE and mutation at the HGPRT locus are not significantly greater than control values. Lewisita toxicity was in some ways similar to radiomimetic chemicals such as bleomycin

Toxicology Studies on Lewisite and Sulfur Mustard Agents: Genetic Toxicity of Sulfur Mustard (HD) in Chinese Hamster Ovary Cells Final Report

The cytotoxic, clastogenic and mutagenic effects of sulfur nustard in Chinese hamster ovary cells are described in this reoort. The cytotoxicity data indicate that micromolar amounts of HC are highly toxic in microrolar amounts. Chromosone aberration frequencies increased in a dose-dependent manner over a dose range of 0. 5 to 1.0 {micro}m and SCE increased in a dose-dependent fashion in the dose range of 0.0625 to 0.25 {micro}M. Mutation induction at the HGPRT locus was sporadic, but the majority of the exoosures resulted in mutation frequencies which were 1.2 to 4.3 fold higher than the spontaneous frequencies

Toxicology Studies on Lewisite and Sulfur Mustard Agents: Genetic Toxicity of Sulfur Mustard (HD) in Chinese Hamster Ovary Cells Final Report

The cytotoxic, clastogenic and mutagenic effects of sulfur nustard in Chinese hamster ovary cells are described in this reoort. The cytotoxicity data indicate that micromolar amounts of HC are highly toxic in microrolar amounts. Chromosone aberration frequencies increased in a dose-dependent manner over a dose range of 0. 5 to 1.0 {micro}m and SCE increased in a dose-dependent fashion in the dose range of 0.0625 to 0.25 {micro}M. Mutation induction at the HGPRT locus was sporadic, but the majority of the exoosures resulted in mutation frequencies which were 1.2 to 4.3 fold higher than the spontaneous frequencies

Prediction modeling for Board of Certification exam success for a professional master’s athletic training program

Introduction: The Commission on Accreditation of Athletic Training Education mandates accredited athletic training programs have a minimum, three-year aggregate, first-attempt pass rate on the Board of Certification (BOC) examination of 70%. No studies have examined first-attempt BOC exam success for students enrolled in a professional master’s athletic training program (PMATP). Purpose: The purpose of this study was to identify factors associated with first-attempt success on the BOC examination for PMATP students. Methods: This cohort designed study used common application data from subjects’ university and PMATP applications to create prediction models to identify those factors that predict first-attempt success on the BOC exam. Results: A four-factor model was produced to predict first-attempt BOC exam success. Both models demonstrated a student with two, three or more predictors had an odds ratio of 16.0 or greater, a relative frequency of success of 1.45 or greater, and correctly predicted first-attempt success on the BOC exam over 92% of the time. Conclusions: It is possible to predict success on the BOC exam for students from a PMATP based on common application data. Recommendations: Although this project involved predicting success on the athletic training certification exam, the procedures and methods used could be adapted to any academic program