Genetic variation of rougheye rockfish (Sebastes aleutianus) and shortraker rockfish (S. borealis) inferred from allozymes

Rougheye rockfish (Sebastes aleutianus) and shortraker rockfish (Sebastes borealis) were collected from the Washington coast, the Gulf of Alaska, the southern Bering Sea, and the eastern Kamchatka coast of Russia (areas encompassing most of their geographic distribution) for population genetic analyses. Using starch gel electrophoresis, we analyzed 1027 rougheye rockfish and 615 shortraker rockfish for variation at 29 proteincoding loci. No genetic heterogeneity was found among shortraker rockfish throughout the sampled regions, although shortraker in the Aleutian Islands region, captured at deeper depths, were found to be significantly smaller in size than the shortraker caught in shallower waters from Southeast Alaska. Genetic analysis of the rougheye rockfish revealed two evolutionary lineages that exist in sympatry with little or no gene f low between them. When analyzed as two distinct species, neither lineage exhibited heterogeneity among regions. Sebastes aleutianus seems to inhabit waters throughout the Gulf of Alaska and more southern waters, whereas S. sp. cf. aleutianus inhabits waters throughout the Gulf of Alaska, Aleutian Islands, and Asia. The distribution of the two rougheye rockfish lineages may be related to depth where they are sympatric. The paler color morph, S. aleutianus, is found more abundantly in shallower waters and the darker color morph, Sebastes sp. cf. aleutianus, inhabits deeper waters. Sebastes sp. cf. aleutianus, also exhibited a significantly higher prevalence of two parasites, N. robusta and T. trituba, than did Sebastes aleutianus, in the 2001 samples, indicating a possible difference in habitat and (or) resource use between the two lineages

The Dependence of Coronal Loop Heating on the Characteristics of Slow Photospheric Motions

The Parker hypothesis (Parker (1972)) assumes that heating of coronal loops occurs due to reconnection, induced when photospheric motions braid field lines to the point of current sheet formation. In this contribution we address the question of how the nature of photospheric motions affects heating of braided coronal loops. We design a series of boundary drivers and quantify their properties in terms of complexity and helicity injection. We examine a series of long-duration full resistive MHD simulations in which a simulated coronal loop, consisting of initially uniform field lines, is subject to these photospheric flows. Braiding of the loop is continually driven until differences in behaviour induced by the drivers can be characterised. It is shown that heating is crucially dependent on the nature of the photospheric driver - coherent motions typically lead to fewer large energy release events, while more complex motions result in more frequent but less energetic heating events

A genetic study of the red-band trout (Salmo sp.)

A group of trout that reside in streams of the desiccating lake basins of southeastern Oregon differ markedly from other known Salmo. Known commonly as the red-band trout, this fish was subjected to chromosome analysis for comparison with other species of western North American Salmo. The karyotype of the red-banded trout is 2n = 58 composed of 44 metacentrics, 2 metacentrics with satallites, 2 sub-metacentrics and 10 acrocentrics to give 104 chromosome arms. This karyotype is identical to that of the California golden trout, S. a.guabonita. A similar karyotype has been found, for trout from the Deschutes River and summer-run steelhead from the Siletz and Clearwater rivers. The chromosomal and distributional data is believed to indicate a widespread golden trout complex composed of the red-band trout, the California golden trout, and the Kern River trout inhabiting the Pacific Coast drainage from British Columbia to southern California. In the course of this study, a new karyotype was discovered for the Alvord cutthroat trout of 2n = 64 with 40 metacentrics and 24 acrocentrics to give 104 chromosome arms. Nineteen enzyme systems were analysed by starch-gel electrophoresis in two populations of the red-band trout. The Bridge Creek population displayed very low variability for only malate dehydroge, nase (MDH) and phosphoglucomutase (PGM). No variability was found in the Three-Mile Creek population. A new allele, not previously reported was found for MDH in the Bridge Creek population. The high degree of genetic similarity among and between these populations is thought to be the result of selection pressure rather than stochastic processes. The isolated populations of the red-banded trout appear to be well adapted to their present environment, but without the genetic variability to meet future environmental changes, they may face extinction. Their most immediate threat is man' s use of the environment

Puppets on a String? How Young Adolescents Explore Gender and Health in Advertising

This article presents qualitative research on young adolescents’ abilities in communicating and evaluating health messages in advertising especially how they understand and create gendered identities. A group of grade 6-8 students learned about media techniques and movie making. In groups divided by gender, they created iMovie advertisements for health activities in their school. They represented themselves in these advertisements by creating stick puppets. Observations during lessons, examination of movies and puppets, and interviews with students and their teacher revealed that young adolescents were neither completely manipulated by media nor were they completely in charge of their responses to media’s messages about gender. Offering students an opportunity to de-brief media experiences also helped them to develop critical media health literacy

Structures of MauG in complex with quinol and quinone MADH

MauG has been cocrystallized with methylamine dehydrogenase (MADH) with its TTQ cofactor in the o-quinol (TTQ(OQ)) and quinone (TTQ(OX)) forms and the structures of the resulting complexes have been solved. The TTQ(OQ) structure crystallized in either space group P2(1) or C2, while the TTQ(OX) structure crystallized in space group P1. The previously solved structure of MauG in complex with MADH bearing an incompletely formed TTQ cofactor (preMADH) also crystallized in space group P1, although with different unit-cell parameters. Despite the changes in crystal form, the structures are virtually identical, with only very minor changes at the protein-protein interface. The relevance of these structures with respect to the measured changes in affinity between MauG and various forms of MADH is discussed

Magnetic reconnection in flux-tubes undergoing spinning footpoint motions

Aims. Photospheric motions acting on the coronal magnetic field have the potential to build up huge amounts of magnetic energy. The energy may be released through magnetic reconnection, and so a detailed understanding of the 3D process is crucial if its implications for coronal heating are to be fully addressed. Methods. A 3D MHD experiment is described in which misaligned magnetic flux tubes are subjected to simple spinning boundary motions. Results. The resulting shear between adjacent flux systems generates a twisted central separator current sheet that extends vertically throughout the domain. Current density is amplified to a sufficient extent that reconnection begins, and occurs everywhere along the separator current sheet, while the separatrix current sheets that exist in the early stages of the experiment are found to be unimportant in the systems dynamical evolution. In 2D cross-sections, the reconnection process exhibits many similarities to the regime of flux pile-up reconnection

Managing Human-Habituated Bears to Enhance Survival, Habitat Effectiveness, and Public Viewing

The negative impacts on bears (Ursus spp.) from human activities associated with roads and developments are well documented. These impacts include displacement of bears from high-quality foods and habitats, diminished habitat effectiveness, and reduced survival rates. Additionally, increased public visitations to national parks accompanied with benign encounters with bears along park roads have caused more bears to habituate to the presence of people. In some contexts, habituation can predispose bears to being exposed to and rewarded by anthropogenic foods, which can also lower survival rates. The managers and staff of Yellowstone National Park located in Wyoming, Montana, and Idaho, USA, and Grand Teton National Park in northwestern Wyoming, USA have implemented several proactive strategies to mitigate the negative aspects of bear habituation. These strategies include providing park visitors with educational information on bear viewing etiquette, managing roadside viewing opportunities, installing bear-resistant infrastructure, hazing bears from developments, enforcing food and garbage storage regulations, and making human activities as predictable as possible to bears. Under the current management strategies, thousands of visitors are still able to view, photograph, and appreciate bears while visiting these parks each year. The opportunity to view bears provides a positive visitor experience and contributes millions of dollars to the local economies of park gateway communities. Positive bear viewing experiences also help build an important appreciation and conservation ethic for bears in people that visit national parks. For many years, managers were concerned about decreasing and threatened bear populations. Now more jurisdictions are facing new challenges caused by increasing bear populations. This paper highlights a successful attempt to address these issues

Book Reviews

Book Review 1Book Title: Early Life Histories of Fishes: New Developmental, Ecological and Evolutionary PerspectivesBook Author: Edited by E.K. BalonDr W. Junk, Dordrecht. 280 pp.Book Review 2Book Title: Comparative Aspects of Extracellular Acid-base BalanceBook Author: J.P. TruchotSpringer, 1987. 248 pp. 51 figures.Book Review 3Book Title: Insect Flight: Dispersal and MigrationBook Author: Edited by W. DanthanarayanaSpringer-Verlag, Berlin, 1986. 289 pp.Book Review 4Book Title:  The Mammalian Herbivore Stomach. Comparative Anatomy, Function and EvolutionBook Author: Peter LangerGustav Fischer, Stuttgart, 1988. 557 pages, 246 figures and 72 tablesBook Review 5Book Title:  Biology of the Integument. Vol. 2: VertebratesBook Authors: Edited by J. Bereiter-Hahn, A.G. Matoltsy & K.S. RichardsSpringer, Berlin, 1986. 855 pp.Book Review 6Book Title:  Advances in the Biology of Turbellarians and related PlatyhelminthesBook Author: Edited by Seth TylerDr. W. Junk Publishers, 1986. 357 pages; 253 figuresBook Review 7Book Title: Evolutionary Physiological EcologyBook Author: Edited by P. CalowCambridge University Press, Cambridge. 239 pp.Book Review 8Book Title: DragonfliesBook Author: Peter L. MillerCambridge University Press, Cambridge, New York and Melbourne, 1987. 84 pp

Domestication of the Annual Legume \u3cem\u3eTrigonella balansae\u3c/em\u3e for Mixed Farming Systems in Southern Australia

An accession of the annual legume Trigonella balansae Boiss. and Reuter. has been selected for commercial release in Australia. The annual legume has significant potential as a self-regenerating pasture within mixed farming systems. As part of a duty-of-care assessment, we tested the hypothesis that sheep grazing the trigonella cultivar will have similar liveweight, condition scores, health and wool production to sheep grazing two widely adopted annual legumes, subterranean clover (Trifolium subterraneum L. cv Dalkeith) and French serradella (Ornithopus sativus Brot. cv. Erica). Forage dry matter digestibility (DMD), crude protein (CP), fibre, mineral content and isoflavones were measured across the plant’s lifecycle. The data supported the hypotheses and there were no significant differences in liveweight, wool growth, wool yield or condition score that were associated with pasture species. The mineral content of trigonella requires further investigation

Diradical intermediate within the context of tryptophan tryptophylquinone biosynthesis

Despite the importance of tryptophan (Trp) radicals in biology, very few radicals have been trapped and characterized in a physiologically meaningful context. Here we demonstrate that the diheme enzyme MauG uses Trp radical chemistry to catalyze formation of a Trp-derived tryptophan tryptophylquinone cofactor on its substrate protein, premethylamine dehydrogenase. The unusual six-electron oxidation that results in tryptophan tryptophylquinone formation occurs in three discrete two-electron catalytic steps. Here the exact order of these oxidation steps in the processive six-electron biosynthetic reaction is determined, and reaction intermediates are structurally characterized. The intermediates observed in crystal structures are also verified in solution using mass spectrometry. Furthermore, an unprecedented Trp-derived diradical species on premethylamine dehydrogenase, which is an intermediate in the first two-electron step, is characterized using high-frequency and -field electron paramagnetic resonance spectroscopy and UV-visible absorbance spectroscopy. This work defines a unique mechanism for radical-mediated catalysis of a protein substrate, and has broad implications in the areas of applied biocatalysis and understanding of oxidative protein modification during oxidative stress