540 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

    Effects of Gear Modifications on the Trawl Performance and Catching Efficiency of the West Coast Upper Continental Slope Groundfish Survey Trawl

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    Since 1984, annual bottom trawl surveys of the west coast (California–Washington) upper continental slope (WCUCS) have provided information on the abundance, distribution, and biological characteristics of groundfish resources. Slope species of the deep-water complex (DWC) are of particular importance and include Dover sole, Microstomus pacificus; sablefish, Anoplopoma fimbria; shortspine thornyhead, Sebastolobus alascanus; and longspine thornyhead, S. altivelis. In the fall of 1994, we conducted an experimental gear research cruise in lieu of our normal survey because of concerns about the performance of the survey trawl. The experiment was conducted on a soft mud bottom at depths of 460–490 m off the central Oregon coast. Treatments included different combinations of door-bridle rigging, groundgear weight, and scope length. The experimental design was a 2 ´ 2 ´ 2 factorial within a randomized complete-block. Analysis of variance was used to examine the effects of gear modifications on the engineering performance of the trawl (i.e. trawl dimensions, variation in trawl dimensions, and door attitude) and to determine if catch rates in terms of weight and number of DWC species and invertebrates were affected by the gear modifications. Trawl performance was highly variable for the historically used standard trawl configuration. Improvements were observed with the addition of either a 2-bridle door or lighter ground gear. Changes in scope length had relatively little effect on trawl performance. The interaction of door bridle and ground gear weight had the most effect on trawl performance. In spite of the standard trawl’s erratic performance, catch rates of all four DWC species and invertebrates were not significantly different than the 2-bridle/heavy combination, which did the best in terms of engineering performance. The most important factor affecting DWC catch rates was ground gear. Scope length and the type of door bridle had little effect on DWC catch rates. Subsequent revisions to survey gear and towing protocol and their impact on the continuity of the slope survey time series are discussed

    A Conceptual Model for a Universal Severity of Emergency Report (USER): An Example in Aviation

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    In emergency situations, it is important that information be communicated quickly, concisely, and efficiently. Breakdowns can occur when the receiver of the emergency call does not fully understand the information that the person is sending. The purpose of this paper is to present a new model for enhancing communication between the sender and receiver in emergency situations. The Universal Severity of Emergency Report (USER) is a model designed to be used in emergency situations and convey more information about the current state of the person declaring the emergency than is currently offered by emergency communication channels. USER provides three key pieces of vital information: severity of the situation, capabilities of the sender, and ability to communicate. Severity identifies the level of the emergency on a scale of 1, 2, or 3. Capabilities use the colors white, yellow, and red to indicate the current self-determined capabilities of the individual. Communicate notifies the receiver if the individual is able to communicate or is unable to communicate. This paper presents this concept in an aviation context, but USER has the potential to be used in any number of industries, including medical, military, shipping, transportation, space flight, and law enforcement

    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.

    Timing and duration of mating and brooding periods of Atka mackerel (Pleurogrammus monopterygius) in the North Pacific Ocean

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    The timing and duration of the reproductive cycle of Atka mackerel (Pleurogrammus monopterygius) was validated by using observations from time-lapse video and data from archival tags, and the start, peak, and end of spawning and hatching were determined from an incubation model with aged egg samples and empirical incubation times ranging from 44 days at a water temperature of 9.85°C to 100 days at 3.89°C. From June to July, males ceased diel vertical movements, aggregated in nesting colonies, and established territories. Spawning began in late July, ended in mid-October, and peaked in early September. The male egg-brooding period that followed continued from late November to mid-January and duration was highly dependent on embryonic development as affected by ambient water temperature. Males exhibited brooding behavior for protracted periods at water depths from 23 to 117 m where average daily water temperatures ranged from 4.0° to 6.2°C. Knowledge about the timing of the reproductive cycle provides a framework for conserving Atka mackerel populations and investigating the physical and biological processes influencing recruitment

    Bourbon Virus in Wild and Domestic Animals, Missouri, USA, 2012–2013

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    Bourbon virus (BRBV) was first isolated from a febrile patient with a history of tick bites in Bourbon County, Kansas, USA; the patient later died from severe illness in 2014 (1). Several additional human BRBV infections were reported subsequently from the midwestern and southern United States (2). BRBV belongs to the family Orthomyxoviridae, genus Thogotovirus, which is distributed worldwide and includes Araguari, Aransas Bay, Dhori, Jos, Thogoto, and Upolu viruses (1,3). Thogoto and Dhori viruses have been associated with human disease (4–6). Viruses within the genus Thogotovirus have been associated with hard or soft ticks (7). Recent studies suggest that the lone star tick (Amblyomma americanum) is involved with BRBV transmission (2,3,8). These ticks feed primarily on mammals, which might play a role in BRBV ecolog

    Potential Use for Serosurveillance of Feral Swine to Map Risk for Anthrax Exposure, Texas, USA

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    Anthrax is a disease of concern in many mammals, including humans. Management primarily consists of prevention through vaccination and tracking clinical-level observations because environmental isolation is laborious and bacterial distribution across large geographic areas diffi cult to confi rm. Feral swine (Sus scrofa) are an invasive species with an extensive range in the southern United States that rarely succumbs to anthrax. We present evidence that feral swine might serve as biosentinels based on comparative seroprevalence in swine from historically defi ned anthrax-endemic and non–anthraxendemic regions of Texas. Overall seropositivity was 43.7% (n = 478), and logistic regression revealed county endemicity status, age-class, sex, latitude, and longitude were informative for predicting antibody status. However, of these covariates, only latitude was statistically signifi cant (β = –0.153, p = 0.047). These results suggests anthrax exposure in swine, when paired with continuous location data, could serve as a proxy for bacterial presence in specifi c areas

    In vitro functional assays to assess the reciprocal interplay between tumor cells and macrophages.

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    Tumor-associated macrophages (TAMs) are integral components of the tumor microenvironment. They are involved in various aspects of tumor cell biology, driving pathological processes such as tumor cell proliferation, metastasis, immunosuppression, and resistance to therapy. TAMs exert their tumorigenic effects by secreting growth factors, cytokines/chemokines, metabolites, and other soluble bioactive molecules. These mediators directly promote tumor cell proliferation and modulate interactions with immune and stromal cells, facilitating further tumor growth. As research into therapies targeting TAMs intensifies, there is a growing need for reliable methods to comprehend the impact of TAMs on cancer progression and to validate novel therapeutics directed at TAMs. The traditional "M1-M2" macrophage classification based on transcriptional profiles of TAMs is not only too simplistic to describe their physiological roles, it also does not explain differences observed between mouse and human macrophages. In this context, methods that assess how TAMs influence tumor or immune cells, either through direct contact or the release of soluble factors, offer a more promising approach. We describe here comprehensive protocols for in vitro functional assays to study TAMs, specifically regarding their impact on the growth of lung cancer cells. We have applied these methods to both mouse and human macrophages, achieving similar outcomes in promoting the proliferation of cancer cells. This methodology can serve as a standardized approach for testing novel therapeutic approaches, targeting TAMs with novel immunotherapeutic compounds, or utilizing gene-editing techniques. Taken together, the described methodology may contribute to our understanding of complex macrophage-tumor interactions and support the development of innovative therapeutic strategies

    Quantifying proximity, confinement, and interventions in disease outbreaks: a decision support framework for air-transported pathogens

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    Includes bibliographical references (pages H-I).The inability to communicate how infectious diseases are transmitted in human environments has triggered avoidance of interactions during the COVID-19 pandemic. We define a metric, Effective ReBreathed Volume (ERBV), that encapsulates how infectious pathogens, including SARS-CoV-2, transport in air. ERBV separates environmental transport from other factors in the chain of infection, allowing quantitative comparisons among situations. Particle size affects transport, removal onto surfaces, and elimination by mitigation measures, so ERBV is presented for a range of exhaled particle diameters: 1, 10, and 100 μm. Pathogen transport depends on both proximity and confinement. If interpersonal distancing of 2 m is maintained, then confinement, not proximity, dominates rebreathing after 10–15 min in enclosed spaces for all but 100 μm particles. We analyze strategies to reduce this confinement effect. Ventilation and filtration reduce person-to-person transport of 1 μm particles (ERBV1) by 13–85% in residential and office situations. Deposition to surfaces competes with intentional removal for 10 and 100 μm particles, so the same interventions reduce ERBV10 by only 3–50%, and ERBV100 is unaffected. Prior knowledge of size-dependent ERBV would help identify transmission modes and effective interventions. This framework supports mitigation decisions in emerging situations, even before other infectious parameters are known
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