871 research outputs found

    Maturation and Reproduction of Shovelnose Sturgeon in the Middle Mississippi River

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    Shovelnose sturgeon Scaphirhynchus platorynchus in the middle Mississippi River provide one of the last commercially viable sturgeon fisheries in the world, yet their maturation and reproduction have not been linked. During 2005 and 2006, we sampled adult and age-0 shovelnose sturgeon to link age at maturation, the timing and periodicity of spawning, age-0 sturgeon production, and the resulting age-0 growth rates. Age at maturity was later than previous estimates, the minimum age of first maturation being 8 years for males and 9 years for females. Total egg count was slightly lower than previously reported (mean = 29,573 per female; SE = 2,472). Males and females typically spawned every 2 and 3 years, respectively. Peaks in mature fish coincided with rising river stages and water temperatures at which shovelnose sturgeon probably spawn. Peaks in spent adults followed. Age-0 shovelnose sturgeon occurred during June and July 2005 and May and June 2006, confirming successful spawning. Age-0 sturgeon grew between 0.69 and 1.69 mm total length/d; four distinct weekly cohorts occurred each year. During fall 2006, females contained ripe eggs, males were milting, and a single age-0 sturgeon (total length = 55 mm) was captured, suggesting that shovelnose sturgeon spawn during fall as well as spring. Management must consider the protracted nature of spawning within seasons as well as differences in spawning activity between seasons

    Parks & Open Space: A Demand & Supply Analysis of Existing Public and Private Open Space in Montgomery County, Maryland

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    Final project for URSP688L: Planning Technologies (Fall 2017). University of Maryland, College Park.Montgomery County Planning’s Energized Public Spaces Functional Master Plan (EPS FMP), which focused primarily on the Silver Spring Central Business District, inventoried the supply of existing parks and open spaces, estimated the demand for parks and open space based on the presence of population and jobs, and identified areas where service gaps exist. The Fall 2017 URSP688L PALS program took the same approach as the EPS FMP, but expanded the study to the whole County, establishing a Set 1 Data and Map. We then created an alternative framework analysis using additional variables to further expand the study’s scope to establish a Set 2 Data and Map. In this alternative framework analysis (Set 2), the park supply for Montgomery County was determined by assigning a score based on amenities in each park. A walkshed was created for each park and the acre grid of Montgomery County in which it is located using a walkshed network analysis that calculated a one mile walk distance from each grid. Park demand was determined by including the following variables: population density, housing density, age, zero car households, and access to private gardens/yards, based on whether a property was multi-family or not. By analyzing the data on public and semi-public parks and factors known to influence their demand, we developed a composite scoring system to identify current service gaps in park lands within Montgomery County, and compared the Set 1 and Set 2 Data. The Set 2 data indicated more significant service gaps in park supply and demand throughout the County, but both Set 1 and Set 2 data indicated a need for more parks in the County’s more rural north and west areas. We recommend undertaking further research using additional variables and advanced analysis tools as this project proceeds into Spring 2018. Part II: http://hdl.handle.net/1903/21108Montgomery Count

    Towards informed and multi-faceted wildlife trade interventions

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    International trade in wildlife is a key threat to biodiversity conservation. CITES, the Convention on International Trade in Endangered Species of Wild Fauna and Flora, is the primary mechanism for controlling international wildlife trade and seeks to ensure it is sustainable, relying on trade bans and controls. However, there has been little comprehensive review of the effectiveness of CITES. Here, we review typical and atypical approaches taken to regulate wildlife trade in CITES and assert that it boasts few successes. We attribute this to: non-compliance, an over reliance on regulation, lack of knowledge of listed species, ignorance of the reality of market forces, and influence among CITES actors. To more effectively manage trade we argue that interventions need to go beyond regulation and should be multi-faceted, reflecting the complexity of wildlife trade. To inform such interventions we assert an intensive research effort is needed and we outline six key research areas: (1) factors undermining wildlife trade governance at the national level, (2) determining sustainable harvest rates for CITES species, (3) gaining the buy-in of local communities in implementing CITES, (4) supply and demand based market interventions, (5) means of quantifying illicit trade, and (6) political processes and influence within CITES

    Distinct and Overlapping Brain Areas Engaged during Value-Based, Mathematical, and Emotional Decision Processing.

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    When comparing between the values of different choices, human beings can rely on either more cognitive processes, such as using mathematical computation, or more affective processes, such as using emotion. However, the neural correlates of how these two types of processes operate during value-based decision-making remain unclear. In this study, we investigated the extent to which neural regions engaged during value-based decision-making overlap with those engaged during mathematical and emotional processing in a within-subject manner. In a functional magnetic resonance imaging experiment, participants viewed stimuli that always consisted of numbers and emotional faces that depicted two choices. Across tasks, participants decided between the two choices based on the expected value of the numbers, a mathematical result of the numbers, or the emotional face stimuli. We found that all three tasks commonly involved various cortical areas including frontal, parietal, motor, somatosensory, and visual regions. Critically, the mathematical task shared common areas with the value but not emotion task in bilateral striatum. Although the emotion task overlapped with the value task in parietal, motor, and sensory areas, the mathematical task also evoked responses in other areas within these same cortical structures. Minimal areas were uniquely engaged for the value task apart from the other two tasks. The emotion task elicited a more expansive area of neural activity whereas value and mathematical task responses were in more focal regions. Whole-brain spatial correlation analysis showed that valuative processing engaged functional brain responses more similarly to mathematical processing than emotional processing. While decisions on expected value entail both mathematical and emotional processing regions, mathematical processes have a more prominent contribution particularly in subcortical processes

    Search for the lepton-family-number nonconserving decay \mu -> e + \gamma

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    The MEGA experiment, which searched for the muon- and electron-number violating decay \mu -> e + \gamma, is described. The spectrometer system, the calibrations, the data taking procedures, the data analysis, and the sensitivity of the experiment are discussed. The most stringent upper limit on the branching ratio of \mu -> e + \gamma) < 1.2 x 10^{-11} was obtained

    Bone marrow stromal cells stimulate an angiogenic program that requires endothelial MT1‐MMP

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    Bone marrow‐derived stromal/stem cells (BMSCs) have recently been characterized as mediators of tissue regeneration after injury. In addition to preventing fibrosis at the wound site, BMSCs elicit an angiogenic response within the fibrin matrix. The mechanistic interactions between BMSCs and invading endothelial cells (ECs) during this process are not fully understood. Using a three‐dimensional, fibrin‐based angiogenesis model, we sought to investigate the proteolytic mechanisms by which BMSCs promote vessel morphogenesis. We find that BMSC‐mediated vessel formation depends on the proteolytic ability of membrane type 1‐matrix metalloproteinase (MT1‐MMP). Knockdown of the protease results in a small network of vessels with enlarged lumens. Contrastingly, vessel morphogenesis is unaffected by the knockdown of MMP‐2 and MMP‐9. Furthermore, we find that BMSC‐mediated vessel morphogenesis in vivo follows mechanisms similar to what we observe in vitro. Subcutaneous, cellular fibrin implants in C.B‐17/SCID mice form aberrant vasculature when MMPs are inhibited with a broad‐spectrum chemical inhibitor, and a very minimal amount of vessels when MT1‐MMP proteolytic activity is interrupted in ECs. Other studies have debated the necessity of MT1‐MMP in the context of vessel invasion in fibrin, but this study clearly demonstrates its requirement in BMSC‐mediated angiogenesis. J. Cell. Physiol. 227: 3546–3555, 2012. © 2012 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92409/1/24056_ftp.pd

    A General Catalogue of Molecular Hydrogen Emission-Line Objects (MHOs) in Outflows from Young Stars

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    We present a catalogue of Molecular Hydrogen emission-line Objects (MHOs) in outflows from young stars, most of which are embedded. All objects are identified in the near-infrared lines of molecular hydrogen, all reside in the Milky Way, and all are associated with jets or molecular outflows from young stars. Objects in both low and high-mass star forming regions are included. This catalogue complements the existing database of Herbig-Haro objects; indeed, for completeness, HH objects that are detected in H2 emission are included in the MHO catalogue.Comment: 8 Pages, 5 figures. Accepted for publication in A&A. Searchable catalogue/Data tables available from http://www.jach.hawaii.edu/UKIRT/MHCat
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