696 research outputs found

    Description of embryonic development of Atka mackerel (Pleurogrammus monopterygius)

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    Atka mackerel (Pleurogrammus monopterygius) is hexagrammid fish that inhabits the temperate and subarctic North Pacific Ocean and neighboring seas (Fig. 1). This highly abundant fish is a critically important prey species (Sinclair and Zeppelin, 2002; Zenger, 2004) that supports a directed commercial trawl fishery (Lowe et al., 2006). Atka mackerel is a demersal spawner and males provide parental care to eggs (Zolotov, 1993). During breeding periods, sexually mature males aggregate on the bottom at nesting sites where they establish territories (Lauth et al., in press). Sexually mature females periodically visit male nesting territories from July to October to spawn batches of demersal egg masses (McDermott and Lowe, 1997; McDermott et al., 2007). Individual nests may consist of multiple egg masses deposited by different females, and males defend nesting territories for a protracted period lasting from the time territories are being established until all eggs within the territory are completely hatched (Lauth et al., 2007). Knowledge about the timing of the reproductive cycle and the use of spawning habitat are important for understanding population structure and the dynamics of stock recruitment, which in turn are important factors in the management of Atka mackerel populations

    Tlingit Women in Leadership: One Culture, Two Worlds

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    This project has been completed through a multi-level stage using the following applications: examination of comprehensive examination of gender equality in Tlingit society (traditional and contemporary) using historical and descriptive research. The Tlingit tribe continues the custom of matrilineal descent (familial lineage is determined through mother) decided clan affiliation, inheritance and disbursal of wealth, tribal and clan leadership. Tlingit culture still continues to be divided into two matrilineal moieties, Raven and Eagle (Wolf). Throughout traditional into present-day Tlingit culture, both men and women continue to be treated equally. The role of Tlingit women include are educating the young, conducting business in the tribal and public sectors and lastly, working to change public policy at the local, state and federal levels of government. Seven Tlingit women leaders (ages from 26 to 87 years old) participated in this qualitative study, which examined influences, challenges and experiences they encountered during their lifetimes. The intent of this researcher focused in the qualities of leadership developed in each participant. Through the use of a questionnaire and a semi-structured interview from each participant resulted in a collection of data. Examination of each participant â„¢s family histories and personal experiences has influenced who they are. This study has focused on how these Tlingit women â„¢s experiences of family/tribal roles, education and life, opportunities as well as barriers, their role models and/or mentors who have shaped their lives. Last to be examined was the participants â„¢ own definition of leadership and their personal and social concerns (specifically role of education, land and cultural preservation, tribal autonomy). These Tlingit women are well-known and respected for their involvement in numerous areas of Business, Management, Politics (at local, state and federal levels). The data collected from these seven participants â„¢ revealed commonalities and how they have shaped their leadership qualities

    H7N9 influenza A virus transmission in a multispecies barnyard model

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    Influenza A viruses are a diverse group of pathogens that have been responsible for millions of human and avian deaths throughout history. Here, we illustrate the transmission potential of H7N9 influenza A virus between Coturnix quail (Coturnix sp.), domestic ducks (Anas platyrhynchos domesticus), chickens (Gallus gallus domesticus), and house sparrows (Passer domesticus) co-housed in an artificial barnyard setting. In each of four replicates, individuals from a single species were infected with the virus. Quail shed virus orally and were a source of infection for both chickens and ducks. Infected chickens transmitted the virus to quail but not to ducks or house sparrows. Infected ducks transmitted to chickens, resulting in seroconversion without viral shedding. House sparrows did not shed virus sufficiently to transmit to other species. These results demonstrate that onward transmission varies by index species, and that gallinaceous birds are more likely to maintain H7N9 than ducks or passerines

    Design considerations for table-top, laser-based VUV and X-ray free electron lasers

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    A recent breakthrough in laser-plasma accelerators, based upon ultrashort high-intensity lasers, demonstrated the generation of quasi-monoenergetic GeV-electrons. With future Petawatt lasers ultra-high beam currents of ~100 kA in ~10 fs can be expected, allowing for drastic reduction in the undulator length of free-electron-lasers (FELs). We present a discussion of the key aspects of a table-top FEL design, including energy loss and chirps induced by space-charge and wakefields. These effects become important for an optimized table-top FEL operation. A first proof-of-principle VUV case is considered as well as a table-top X-ray-FEL which may open a brilliant light source also for new ways in clinical diagnostics.Comment: 6 pages, 4 figures; accepted for publication in Appl. Phys.

    Viral shedding of clade 2.3.4.4 H5 highly pathogenic avian influenza A viruses by American robins

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    American robins (Turdus migratorius) are commonly associated with farmsteads in the United States and have shown previous evidence of exposure to an H5 avian influenza A virus (IAV) near a poultry production facility affected by a highly pathogenic (HP) H5 virus in Iowa, USA during 2015. We experimentally infected American robins with three clade 2.3.4.4 HP H5 viruses (H5N2 and H5N8). A total of 22/24 American robins shed virus, and all three strains were represented. The highest virus titres shed were 104.3, 104.3 and 104.8 PFU/ml, associated respectively with viruses isolated from poultry, a captive gyrfalcon (Falco rusticolus), and a Northern pintail (Anas acuta). Of those birds that shed, viral shedding was initiated 1 or 2 days post‐infection (DPI) and shedding ceased in all birds by 7 DPI. This study adds an additional synanthropic wildlife species to a growing list of animals that can successfully replicate and shed IAVs

    Viral shedding of clade 2.3.4.4 H5 highly pathogenic avian influenza A viruses by American robins

    Get PDF
    American robins (Turdus migratorius) are commonly associated with farmsteads in the United States and have shown previous evidence of exposure to an H5 avian influenza A virus (IAV) near a poultry production facility affected by a highly pathogenic (HP) H5 virus in Iowa, USA during 2015. We experimentally infected American robins with three clade 2.3.4.4 HP H5 viruses (H5N2 and H5N8). A total of 22/24 American robins shed virus, and all three strains were represented. The highest virus titres shed were 104.3, 104.3 and 104.8 PFU/ml, associated respectively with viruses isolated from poultry, a captive gyrfalcon (Falco rusticolus), and a Northern pintail (Anas acuta). Of those birds that shed, viral shedding was initiated 1 or 2 days post‐infection (DPI) and shedding ceased in all birds by 7 DPI. This study adds an additional synanthropic wildlife species to a growing list of animals that can successfully replicate and shed IAVs
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