7 research outputs found

    Impacts of colonial waterbirds on vegetation and potential restoration of island habitats

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    Colonial waterbirds have impacted forested island ecosystems throughout their breeding range, changing vegetation, and soil characteristics and bird communities. Our objectives were to (1) determine effects of three levels of colonial waterbird exclusion on overall vegetation diversity and growth, and survival of a candidate restoration species (black elderberry; Sambucus nigra canadensis); (2) investigate effects of different planting techniques on survival and growth of black elderberry; and (3) determine effects of waterbird colonization on soil chemistry. In 2012, we investigated effects of three levels of waterbird exclusion (none control plots [CON]; partial, which excluded waterbirds larger than gulls [PEX]; and full which excluded all waterbirds [FEX]) on bird use, existing vegetation growth and diversity, and survival of planted black elderberry on three islands in Door County, WI, Lake Michigan. In 2013, we evaluated survival of black elderberry established with four planting treatments within three waterbird exclusion treatments on two islands in 2013.We also compared soil chemistry characteristics between islands with and without nesting waterbirds for 2 years. Overall plant growth was greater in exclosures, but elderberry survival was similar among treatments. Soil replacement and weed suppression planting treatments did not affect survival, but generally increased overall elderberry biomass. Soil from nesting islands was more acidic and had greater nutrient concentrations than reference islands. Exclusion or removal of colonial nesting waterbirds from islands may improve overall vegetation growth, but successful restoration of woody vegetation may require significant soil manipulation and planting

    Sensitization of spinal cord nociceptive neurons with a conjugate of substance P and cholera toxin

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    <p>Abstract</p> <p>Background</p> <p>Several investigators have coupled toxins to neuropeptides for the purpose of lesioning specific neurons in the central nervous system. By producing deficits in function these toxin conjugates have yielded valuable information about the role of these cells. In an effort to specifically stimulate cells rather than kill them we have conjugated the neuropeptide substance P to the catalytic subunit of cholera toxin (SP-CTA). This conjugate should be taken up selectively by neurokinin receptor expressing neurons resulting in enhanced adenylate cyclase activity and neuronal firing.</p> <p>Results</p> <p>The conjugate SP-CTA stimulates adenylate cyclase in cultured cells that are transfected with either the NK1 or NK2 receptor, but not the NK3 receptor. We further demonstrate that intrathecal injection of SP-CTA in rats induces the phosphorylation of the transcription factor cyclic AMP response element binding protein (CREB) and also enhances the expression of the immediate early gene c-Fos. Behaviorally, low doses of SP-CTA (1 ÎŒg) injected intrathecally produce thermal hyperalgesia. At higher doses (10 ÎŒg) peripheral sensitivity is suppressed suggesting that descending inhibitory pathways may be activated by the SP-CTA induced sensitization of spinal cord neurons.</p> <p>Conclusion</p> <p>The finding that stimulation of adenylate cyclase in neurokinin receptor expressing neurons in the spinal cord produces thermal hyperalgesia is consistent with the known actions of these neurons. These data demonstrate that cholera toxin can be targeted to specific cell types by coupling the catalytic subunit to a peptide agonist for a g-protein coupled receptor. Furthermore, these results demonstrate that SP-CTA can be used as a tool to study sensitization of central neurons in vivo in the absence of an injury.</p

    DNA bending by bHLH charge variants

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    We wish to understand the role of electrostatics in DNA stiffness and bending. The DNA charge collapse model suggests that mutual electrostatic repulsions between neighboring phosphates significantly contribute to DNA stiffness. According to this model, placement of fixed charges near the negatively charged DNA surface should induce bending through asymmetric reduction or enhancement of these inter-phosphate repulsive forces. We have reported previously that charged variants of the elongated basic-leucine zipper (bZIP) domain of Gcn4p bend DNA in a manner consistent with this charge collapse model. To extend this result to a more globular protein, we present an investigation of the dimeric basic-helix–loop–helix (bHLH) domain of Pho4p. The 62 amino acid bHLH domain has been modified to position charged amino acid residues near one face of the DNA double helix. As observed for bZIP charge variants, DNA bending toward appended cations (away from the protein:DNA interface) is observed. However, unlike bZIP proteins, DNA is not bent away from bHLH anionic charges. This finding can be explained by the structure of the more globular bHLH domain which, in contrast to bZIP proteins, makes extensive DNA contacts along the binding face

    Impacts of colonial waterbirds on vegetation and potential restoration of island habitats

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    Colonial waterbirds have impacted forested island ecosystems throughout their breeding range, changing vegetation, and soil characteristics and bird communities. Our objectives were to (1) determine effects of three levels of colonial waterbird exclusion on overall vegetation diversity and growth, and survival of a candidate restoration species (black elderberry; Sambucus nigra canadensis); (2) investigate effects of different planting techniques on survival and growth of black elderberry; and (3) determine effects of waterbird colonization on soil chemistry. In 2012, we investigated effects of three levels of waterbird exclusion (none control plots [CON]; partial, which excluded waterbirds larger than gulls [PEX]; and full which excluded all waterbirds [FEX]) on bird use, existing vegetation growth and diversity, and survival of planted black elderberry on three islands in Door County, WI, Lake Michigan. In 2013, we evaluated survival of black elderberry established with four planting treatments within three waterbird exclusion treatments on two islands in 2013.We also compared soil chemistry characteristics between islands with and without nesting waterbirds for 2 years. Overall plant growth was greater in exclosures, but elderberry survival was similar among treatments. Soil replacement and weed suppression planting treatments did not affect survival, but generally increased overall elderberry biomass. Soil from nesting islands was more acidic and had greater nutrient concentrations than reference islands. Exclusion or removal of colonial nesting waterbirds from islands may improve overall vegetation growth, but successful restoration of woody vegetation may require significant soil manipulation and planting

    Perceived impacts of wild turkeys and management techniques for Wisconsin ginseng production

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    The restoration of eastern wild turkeys (Meleagris gallopavo silvestris; Viellot) within Wisconsin has successfully populated the central counties which account for 95% of American ginseng (Panax quinquefolius L.) production. In response to perceived and emerging conflicts, the Ginseng Board of Wisconsin, Inc. conducted producer surveys in March 2006 and 2012 to determine the extent and timing of wild turkey damage experienced among all Wisconsin ginseng producers, and the methods used to minimize wild turkey damage. We summarized 47 and 63 completed surveys in 2006 and 2012, respectively. Most survey respondents reported that wild turkeys were present and caused damage at their ginseng facilities every year. Turkey damage was regarded as “moderate” among most survey respondents. The majority of respondents in 2006 reported that annual losses were 2000−2000-5000, while most respondents in 2012 reported losses of less than 2000.Mostproducersreportedspendinglessthan2000. Most producers reported spending less than 2000 annually for turkey damage management. Vertical fencing was reported as the most used and most effective damage management technique; the reported use and long-term efficacy of vertical fencing increasing substantially from 2006 to 2012. The increased use of vertical fencing may be related to the general downtrend in annual monetary losses due to wild turkeys from 2006 to 2012. These survey results will be used to further identify, investigate and manage the impacts of wild turkeys to Wisconsin ginseng production

    Raccoon (\u3ci\u3eProcyon lotor\u3c/i\u3e) biomarker and rabies antibody response to varying oral rabies vaccine bait densities in northwestern Pennsylvania

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    Distribution of oral rabies vaccine baits has been used as a strategy for managing rabies in the United States since the 1990s. Since that time, efforts have been made to improve baiting strategies with a focus on bait density to maximize both efficiency and cost effectiveness. An optimal rabies management strategy includes a vaccine bait preferred by the target species that is distributed at the minimal density needed to achieve population immunity to prevent rabies spread. The purpose of our pilot study was to examine the effect of 75, 150, and 300 baits/km2 vaccine bait densities on rabies virus neutralizing antibody (RVNA) seroprevalence in raccoons (Procyon lotor). Raboral V-RG_ fishmeal polymer baits (Merial Inc. (now a part of Boehringer Ingelheim), Athens, Georgia) contain a tetracycline biomarker that was used to estimate bait consumption as another measure of intervention impact. Our results suggest that raccoon RVNA response increases as bait density increases, but the effect may not be sufficient to justify the cost except in the case of contingency actions or an epizootic. Non-target species, especially opossums (Didelphis virginianus) in certain areas, should be considered when determining an appropriate bait density to ensure sufficient baits are available for consumption by the target species
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