Multilayer refractory nozzles produced by plasma-spray process

Multilayer rocket nozzles formed by plasma spraying have good thermal shock resistance and can be reheated in an oxidizing environment without loss of coating adherence. Suggested application of this process are for the production of refractory components, which can be formed as surfaces of revolution

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

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

A Case Study of the Identity Development of an Adolescent Male with Emotional Disturbance and 48, XYYY Karyotype in an Institutional Setting

The goal of this study was to utilize a phenomenological case study design to investigate the individual and social identity development of an adolescent male who had been placed in a high-security group home setting. The participant had been identified with emotional disturbance (ED), and 48, XYYY karyotype. The participant described his social and emotional development as being impacted by his environment, his level of personal control, and his view of the future

Redescription of \u3ci\u3eDiandrya composita\u3c/i\u3e Darrah, 1930 (Cestoda: Anoplocephalidae) from Nearctic Marmots (Rodentia: Sciuridae) and the Relationships of the Genus \u3ci\u3eDiandrya\u3c/i\u3e emend.

According to the original description of Diandrya composita Darrah, 1930 (the type and only species of the Nearctic genus Diandrya Darrah, 1930) , this cestode would possess a combination of organs, the interproglottidal glands and pedunculated prostate glands, otherwise unknown in any member of the Anoplocephalidae. Neither of these organs is present in D. composita . This species is redescribed and the generic diagnosis is emended accordingly. Diandrya composita has its closest affinities with cestodes of the genus Andrya Railliet, 1893, from which it differs significantly only in reduplication of the reproductive organs

Studies on the Helminth Fauna of Alaska. XXXVIl. Description of \u3ci\u3eSchizorchis caballeroi\u3c/i\u3e n. sp. (Cestoda: Anoplocephalidae), with Notes on Other Parasites of \u3ci\u3eOchotona\u3c/i\u3e

Schizorchis caballeroi n. sp. has been described from the collared pika, Ochotona collaris (Nelson), from Alaska, and has been distinguished morphologically from its congeners, S. ochotonae Hansen, 1948, and S. altaica Gvozdev, 1951. Nine species of helminths have been described 10 dale from North American pikas, O. collaris and O. princeps (Richardson). These mammals are markedly allopatric and do not share any species of helminth. Nematodes of two genera, Eugenuris Shults and Labiostomum Akhtar, 1941, occur in O. collaris as weIl as in palearctic species of Ochotona. This, along with other pertinent information, is taken to suggest that O. collaris has invaded North American more recently than did O. princeps or its precursor

Paneak\u27s Plants and Animals [\u3ci\u3eIn a Hungry Country\u3c/i\u3e: Appendix 1]

A list of plants and animals recognized by Simon Paneak (1900-1975), a Nunamiut Eskimo. Names are given in English and Iñupiaq, and their scientific names are provided