1,361 research outputs found

    North American Moose, by R.L. Peterson

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    Kangaroo Harvesting And The Conservation Of Arid And Semi-Arid Rangelands

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    This article argues that a reduction in sheep numbers within the sheep rangelands would lead to an increase in kangaroos, improvement in the vegetation, and a reduction in soil erosion. An increase in the market value of kangaroo products would provide a mechanism for this, by making the replacement of sheep by kangaroos an economically attractive proposition, leading to environmental rehabilitation. Thus, a renewable resource (kangaroos) can be used to save a non-renewable resource (the habitat)

    Hard probes in heavy ion collisions at the LHC: PDFs, shadowing and pApA collisions

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    This manuscript is the outcome of the subgroup ``PDFs, shadowing and pApA collisions'' from the CERN workshop ``Hard Probes in Heavy Ion Collisions at the LHC''. In addition to the experimental parameters for pApA collisions at the LHC, the issues discussed are factorization in nuclear collisions, nuclear parton distributions (nPDFs), hard probes as the benchmark tests of factorization in pApA collisions at the LHC, and semi-hard probes as observables with potentially large nuclear effects. Also, novel QCD phenomena in pApA collisions at the LHC are considered. The importance of the pApA program at the LHC is emphasized.Comment: The writeup of the working group "PDFs, shadowing and pApA collisions" for the CERN Yellow Report on Hard Probes in Heavy Ion Collisions at the LHC, 121 pages. Subgroup convenors: K.J. Eskola, J.w. Qiu (theory) and W. Geist (experiment). Editor: K.J. Eskol

    Incorporating Wildlife Connectivity into Forest Plan Revision Under the United States Forest Service\u27s 2012 Planning Rule

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    The United States Forest Service promulgated new planning regulations under the National Forest Management Act in 2012 (i.e., the Planning Rule). These new regulations include the first requirements in U.S. public land management history for National Forests to evaluate, protect, and/or restore ecological connectivity as they revise their land management plans. Data and resource limitations make single-species, functional connectivity analyses for the myriad species that occur within the 78 million ha the Forest Service manages implausible. We describe an approach that relies on freely available data and generic species, virtual species whose profile consists of ecological requirements designed to reflect the needs of a group of real species, to address the new Planning Rule requirements. We present high-resolution connectivity estimates for 10 different generic species across a 379,000 ha study area centered on the Custer Gallatin National Forest (CGNF) in Montana and South Dakota under two different movement models. We identify locations important for connectivity for multiple species and characterize the role of the CGNF for regional connectivity. Our results informed the Plan Revision process on the CGNF and could be readily exported to other National Forests currently or planning to revise their land management plans under the new Planning Rule

    Multi-vessel stenting during primary percutaneous coronary intervention for acute myocardial infarction. A single-center experience

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    BACKGROUND: Recanalization of the culprit lesion is the main goal of primary angioplasty for acute ST-segment elevation myocardial infarction (STEMI). Patients presenting with acute myocardial infarction and multivessel disease are, therefore, usually subjected to staged procedures, with the primary percutaneous coronary intervention (PCI) confined to recanalization of the infarct-related artery (IRA). Theoretically at least, early relief of stenoses of non-infarct-related arteries could promote collateral circulation, which could help to limit the infarct size. However, the safety and feasibility of such an approach has not been adequately established. METHODS: In this single-center prospective study we examined 73 consecutive patients who had an acute STEMI and at least one or more lesions > or = 70% in a major epicardial vessel other than the infarct-related artery. In the first 28 patients, forming the multi-vessel (MV) PCI group, all lesions were treated during the primary procedure. In the following 45 patients, forming the culprit-only (CO) PCI group, only the culprit lesion was treated during the initial procedure, followed by either planned-staged or ischemia-driven revascularization of the non-culprit lesions. Fluoroscopy time and contrast dye amount were compared between both groups, and patients were followed up for one year for major adverse cardiac events (MACE) and other significant clinical events. RESULTS: The two groups were well balanced in terms of clinical characteristics, number of diseased vessels and angiographic characteristics of the culprit lesion. In the MV-PCI group, 2.51 lesions per patient were treated using 2.96 +/- 1.34 stents (1.00 lesions and 1.76 +/- 1.17 stents in the CO-PCI group, both p < 0.001). The fluoroscopy time increased from 10.3 (7.2-16.9) min in the CO-PCI group to 12.5 (8.5-19.3) min in the MV-PCI group (p = 0.22), and the amount of contrast used from 200 (180-250) ml to 250 (200-300) ml, respectively (p = 0.16). Peak CK and CK-MB were significantly lower in patients of the MV-PCI group (843 +/- 845 and 135 +/- 125 vs 1652 +/- 1550 and 207 +/- 155 U/l, p < 0.001 and 0.01, respectively). Similar rates of major adverse cardiac events at one year were observed in the two groups (24% and 28% in multi-vessel and culprit treatment groups, p = 0.73). The incidence of new revascularization in both infarct- and non-infarct-related arteries was also similar (24% and 28%, respectively, p = 0.73). CONCLUSION: We may state from this limited experience that a multi-vessel stenting approach for patients with acute STEMI and multi-vessel disease is feasible and probably safe during routine clinical practice. Our data suggest that this approach may help to limit the infarct size. However, larger studies, perhaps using drug-eluting stents, are still needed to further evaluate the safety and efficiency of this procedure, and whether it is associated with a lower need of subsequent revascularization and lower costs

    Linking mechanistic and behavioral responses to sublethal esfenvalerate exposure in the endangered delta smelt; Hypomesus transpacificus (Fam. Osmeridae)

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    <p>Abstract</p> <p>Background</p> <p>The delta smelt (<it>Hypomesus transpacificus</it>) is a pelagic fish species listed as endangered under both the USA Federal and Californian State Endangered Species Acts and considered an indicator of ecosystem health in its habitat range, which is limited to the Sacramento-San Joaquin estuary in California, USA. Anthropogenic contaminants are one of multiple stressors affecting this system, and among them, current-use insecticides are of major concern. Interrogative tools are required to successfully monitor effects of contaminants on the delta smelt, and to research potential causes of population decline in this species. We have created a microarray to investigate genome-wide effects of potentially causative stressors, and applied this tool to assess effects of the pyrethroid insecticide esfenvalerate on larval delta smelt. Selected genes were further investigated as molecular biomarkers using quantitative PCR analyses.</p> <p>Results</p> <p>Exposure to esfenvalerate affected swimming behavior of larval delta smelt at concentrations as low as 0.0625 ÎĽg.L<sup>-1</sup>, and significant differences in expression were measured in genes involved in neuromuscular activity. Alterations in the expression of genes associated with immune responses, along with apoptosis, redox, osmotic stress, detoxification, and growth and development appear to have been invoked by esfenvalerate exposure. Swimming impairment correlated significantly with expression of aspartoacylase (ASPA), an enzyme involved in brain cell function and associated with numerous human diseases. Selected genes were investigated for their use as molecular biomarkers, and strong links were determined between measured downregulation in ASPA and observed behavioral responses in fish exposed to environmentally relevant pyrethroid concentrations.</p> <p>Conclusions</p> <p>The results of this study show that microarray technology is a useful approach in screening for, and generation of molecular biomarkers in endangered, non-model organisms, identifying specific genes that can be directly linked with sublethal toxicological endpoints; such as changes in expression levels of neuromuscular genes resulting in measurable swimming impairments. The developed microarrays were successfully applied on larval fish exposed to esfenvalerate, a known contaminant of the Sacramento-San Joaquin estuary, and has permitted the identification of specific biomarkers which could provide insight into the factors contributing to delta smelt population decline.</p

    Exploring the Subtle Effect of Aliphatic Ring Size on Minor Actinide-Extraction Properties and Metal Ion Speciation in Bis-1,2,4-Triazine Ligands

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    Calling all actinides! Bis-1,2,4-triazine ligands bearing five-membered rings were synthesized and evaluated as actinide-selective extractants. Tuning the size of the aliphatic ring leads to subtle changes in actinide-extraction properties. The origins of these changes were elucidated at the molecular level, paving the way for the rational design of improved actinide-selective extractants for reprocessing of spent nuclear fuel., The synthesis and evaluation of three novel bis-1,2,4-triazine ligands containing five-membered aliphatic rings are reported. Compared to the more hydrophobic ligands 1–3 containing six-membered aliphatic rings, the distribution ratios for relevant f-block metal ions were approximately one order of magnitude lower in each case. Ligand 10 showed an efficient, selective and rapid separation of AmIII and CmIII from nitric acid. The speciation of the ligands with trivalent f-block metal ions was probed using NMR titrations and competition experiments, time-resolved laser fluorescence spectroscopy and X-ray crystallography. While the tetradentate ligands 8 and 10 formed LnIII^{III} complexes of the same stoichiometry as their more hydrophobic analogues 2 and 3, significant differences in speciation were observed between the two classes of ligand, with a lower percentage of the extracted 1:2 complexes being formed for ligands 8 and 10. The structures of the solid state 1:1 and 1:2 complexes formed by 8 and 10 with YIII^{III}, LuIII^{III} and PrIII^{III} are very similar to those formed by 2 and 3 with LnIII^{III}. Ligand 10 forms CmIII^{III} and EuIII^{III} 1:2 complexes that are thermodynamically less stable than those formed by ligand 3, suggesting that less hydrophobic ligands form less stable AnIII^{III} complexes. Thus, it has been shown for the first time how tuning the cyclic aliphatic part of these ligands leads to subtle changes in their metal ion speciation, complex stability and metal extraction affinity

    Access to justice for all: Towards an “expansive vision” of justice and technology.

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    In this paper, the authors examine developments in the Canadian access to justice dialogue from Macdonald’s seminal 2005 analysis to the recent reports of the National Action Committee on Access to Justice in Civil and Family Matters [NAC]. They draw on the NAC’s call for an “expansive vision” of access to justice as the basis for critically evaluating examples of particular technologies used or proposed as responses to the access to justice crisis in Canada. In so doing, they illustrate the importance of conscious consideration of deliverables and beneficiaries in prioritizing technologies for deployment, in determining how the technology ought to be deployed, and in evaluating the potential of a technology to facilitate access to justice. The authors argue that nuanced accounts of the relationships between justice deliverables, technological mechanisms for delivery and intended justice beneficiaries are essential to developing good decision-making mechanisms with respect to access to justice and technology. Dans le présent article, les auteurs examinent l’évolution du dialogue canadien sur l’accès à la justice, depuis l’analyse fondamentale de Macdonald en 2005 jusqu’aux récents rapports du Comité national d’action sur l’accès à la justice en matière civile et familiale (CNA). Ils se fondent sur la « vision élargie » de l’accès à la justice réclamée par le CNA pour évaluer de façon critique les exemples de technologies particulières utilisées ou proposées pour répondre à la crise de l’accès à la justice au Canada. Ce faisant, ils illustrent l’importance d’examiner de façon consciente les livrables et les bénéficiaires pour classer par ordre de priorité les technologies à déployer, pour déterminer comment la technologie devrait être déployée et pour évaluer le potentiel d’une technologie de faciliter l’accès à la justice. Les auteurs soutiennent que des comptes rendus nuancés des rapports entre les livrables en matière de justice, les mécanismes de livraison technologiques et les bénéficiaires prévus sont essentiels pour élaborer de bons mécanismes décisionnels en ce qui concerne l’accès à la justice et la technologie

    A Poincare-Covariant Parton Cascade Model for Ultrarelativistic Heavy-Ion Reactions

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    We present a new cascade-type microscopic simulation of nucleus-nucleus collisions at RHIC energies. The basic elements are partons (quarks and gluons) moving in 8N-dimensional phase space according to Poincare-covariant dynamics. The parton-parton scattering cross sections used in the model are computed within perturbative QCD in the tree-level approximation. The Q^2 dependence of the structure functions is included by an implementation of the DGLAP mechanism suitable for a cascade, so that the number of partons is not static, but varies in space and time as the collision of two nuclei evolves. The resulting parton distributions are presented, and meaningful comparisons with experimental data are discussed.Comment: 30 pages. 11 figures. Submitted to Phys.Rev.
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