2,255 research outputs found

    Effects of Sex, Age, and Habitat on Northern Bobwhite Spring Dispersal Patterns

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    Information on northern bobwhite (Colinus virginianus) dispersal patterns is crucial for implementing effective management strategies. Researchers have examined bobwhite dispersal, but information on how habitat affects dispersal patterns is lacking. We examined the effects of habitat, sex, and age on bobwhite spring dispersal patterns in a southern Georgia agricultural landscape during 2002-2003. Of 101 birds used in our analyses, 29.7% (4.6 SE) dispersed an average of 1,835m (194 SE). We fit 9 logistic regression models to predict bobwhite dispersal probability. The selected best model (Akaike weight [ω] = 0.58) included age, proportions of closed-canopy pine within winter home ranges (CCPN), and an age*CCPN interaction term. Adults with higher proportions of closed-canopy pine within their winter home range were more likely to disperse (ß = 0.18, 0.06 SE). Because of greater experience, adults may perceive habitat differently than juveniles, which could influence adult tendency to disperse. However, a significant portion of birds from both age classes will likely disperse every spring, regardless of habitat quality. Although dispersal may allow bobwhite populations to persist in fragmented landscapes, efforts to increase bobwhite populations at the local scale are hindered if emigration exceeds immigration. Therefore, it is important to consider landscape quality and management unit size when determining which areas are most likely to respond to management and the proper management strategy needed to achieve bobwhite population objectives

    Estimating Sample Sizes for Distance Sampling of Autumn Northern Bobwhite Calling Coveys

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    Point transect sampling of calling coveys has been advocated for estimating autumn abundance of northern bobwhite (Colinus virginianus; hereafter bobwhite). We conducted power analysis, over a range of expected bobwhite calling covey densities to determine levels of sampling required to obtain density estimates for calling coveys over a wide range of precision. We used distance/detection information for autumn bobwhite coveys from 701 observer-mornings on 39 farms in the Upper Coastal Plain of Georgia to construct a global detection function (Uniform with cosine adjustment) using Program DISTANCE. We used simulation models to determine the expected coefficient of variation (CV) on density in relation to number of points sampled. We generated 1,000 sets of random samples in increments of 10 at sample sizes of 10-1,000. At each sample size we generated the respective number of observations from a Poisson distribution with λ = 0.5-3.0 and computed the density and associated statistics using the global detection function. We report the mean CV on covey density at each sample size. As expected, the CV on density decreased with increasing sample size and expected number of detections per point. Assuming sufficient observations to estimate the detection function, a CV on density \u3c15% could be achieved with 50 points at densities with a mean detection of 1 covey/point or 20 points with a mean detection of 2 coveys/point. A mean CV \u3c10% required 100 points at 1 covey/point and 30 points at 2 coveys/point. These simulations demonstrate that distance-based autumn covey surveys can provide density estimates for calling coveys with reasonable precision given sufficient effort

    Silly Questions and Arguments for the Implicit, Cinematic Narrator

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    My chapter aims to advance the debate on a problem often raised by philosophers who are skeptical of implied narrators in movies. This is the concern that positing such elusive narrators gives rise to absurd imaginings (Gaut 2004: 242; Carroll 2006: 179-180). Friends of the implied cinematic narrator reply that the questions critics raise about the workings of the implied cinematic narrator are "silly ones" to ask. I examine how the "absurd imaginings" problem arises for all the central arguments for the elusive cinematic narrator and discuss why the questions critics pose about this narrator are legitimate ones to ask

    Explorations, Vol. 4, No. 2

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    Articles include: Cover: Maya—painted clay figure from Jaina Island, Campeche, Mexico, 500-700A. D., approximately 100 percent. The clay figure is from a superb assemblage of pre-Hispanic materials from Mexico and Central America donated to the University of Maine’s Hudson Museum from the estate of William P Palmer III. In addition to this fine collection, Palmer donated an extensive array of objects from the Northwest Coast. Palmer earned his undergraduate degree in history and government from the University of Maine, and remained a strong, active supporter of the institution throughout his lifetime. More examples of objects from the Palmer Collection, including some pre-Columbian goldwork from Central America, may be found on page 10. Editorial Reflections, by Carole J. Bombard A Living Educational Experience: The Hudson Museum, by Richard G. Emerick Molly in the Museum Other Wonders, Other Ways From Classroom Walls to High Tech Museum Sharing Our Strengths: the development of youth conservation clubs in Pakistan, by James A. Sherburne Up Close and Personal Objects, Signs, and Symbols from Scafell to Chamonix: Visions of Mont Blanc, by Robert Brinkley Public Service in Special Places: Music Education as Empowerment, by Susan Grindel Cosset Lambs, Floods and Stars, by Roberta Chester Tuning the Immune System Fighting AIDS, Cancer and Other Diseases, by Anne P. Sherblom and Charles E. Moody Why do they do it? One Graduate Student Explains, by Diane Carroll Nutrition and Reproduction in Cows, by Barbara Barton and Diane Carroll Diane Carroll: former graduate student Research News Research New

    An unexpected link between fatty acid synthase and cholesterol synthesis in proinflammatory macrophage activation

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    Different immune activation states require distinct metabolic features and activities in immune cells. For instance, inhibition of fatty acid synthase (FASN), which catalyzes the synthesis of long-chain fatty acids, prevents the proinflammatory response in macrophages; however, the precise role of this enzyme in this response remains poorly defined. Consistent with previous studies, we found here that FASN is essential for lipopolysaccharide-induced, Toll-like receptor (TLR)-mediated macrophage activation. Interestingly, only agents that block FASN upstream of acetoacetyl-CoA synthesis, including the well-characterized FASN inhibitor C75, inhibited TLR4 signaling, while those acting downstream had no effect. We found that acetoacetyl-CoA could overcome C75's inhibitory effect, whereas other FASN metabolites, including palmitate, did not prevent C75-mediated inhibition. This suggested an unexpected role for acetoacetyl-CoA in inflammation that is independent of its role in palmitate synthesis. Our evidence further suggested that acetoacetyl-CoA arising from FASN activity promotes cholesterol production, indicating a surprising link between fatty acid synthesis and cholesterol synthesis. We further demonstrate that this process is required for TLR4 to enter lipid rafts and facilitate TLR4 signaling. In conclusion, we have uncovered an unexpected link between FASN and cholesterol synthesis that appears to be required for TLR signal transduction and proinflammatory macrophage activation

    Inflammasome priming in sterile inflammatory disease

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    The inflammasome is a cytoplasmic protein complex that processes interleukins (IL)-1β and IL-18, and drives a form of cell death known as pyroptosis. Oligomerization of this complex is actually the second step of activation, and a priming step must occur first. This involves transcriptional upregulation of pro-IL-1β, inflammasome sensor NLRP3, or the non-canonical inflammasome sensor caspase-11. An additional aspect of priming is the post-translational modification of particular inflammasome constituents. Priming is typically accomplished in vitro using a microbial Toll-like receptor (TLR) ligand. However, it is now clear that inflammasomes are activated during the progression of sterile inflammatory diseases such as atherosclerosis, metabolic disease, and neuroinflammatory disorders. Therefore, it is time to consider the endogenous factors and mechanisms that may prime the inflammasome in these conditions

    Publishing and sharing multi-dimensional image data with OMERO

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    Imaging data are used in the life and biomedical sciences to measure the molecular and structural composition and dynamics of cells, tissues, and organisms. Datasets range in size from megabytes to terabytes and usually contain a combination of binary pixel data and metadata that describe the acquisition process and any derived results. The OMERO image data management platform allows users to securely share image datasets according to specific permissions levels: data can be held privately, shared with a set of colleagues, or made available via a public URL. Users control access by assigning data to specific Groups with defined membership and access rights. OMERO’s Permission system supports simple data sharing in a lab, collaborative data analysis, and even teaching environments. OMERO software is open source and released by the OME Consortium at www.openmicroscopy.org
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