57 research outputs found

    Spatiotemporal requirements of the Hainan gibbon: Does home range constrain recovery of the world's rarest ape?

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    Conservation management requires an evidence-based approach, as uninformed decisions can signify the difference between species recovery and loss. The Hainan gibbon, the world’s rarest ape, reportedly exploits the largest home range of any gibbon species, with these apparently large spatial requirements potentially limiting population recovery. However, previous home range assessments rarely reported survey methods, effort or analytical approaches, hindering critical evaluation of estimate reliability. For extremely rare species where data collection is challenging, it also is unclear what impact such limitations have on estimating home range requirements. We re-evaluated Hainan gibbon spatial ecology using 75 hours of observations from 35 contact days over 93 field-days across wet (June 2011-September 2011) and dry (November 2010-February 2011) seasons. We calculated home range area for three social groups (N=21 individuals) across the sampling period, seasonal estimates for one group (based on 24 days of observation; 12 days per season), and between-group home range overlap using multiple approaches (Minimum Convex Polygon, Kernel Density Estimation, Local Convex Hull, Brownian Bridge Movement Model), and assessed estimate reliability and representativeness using three approaches (Incremental Area Analysis, spatial concordance, and exclusion of expected holes). We estimated a yearly home range of 1–2 km2, with 1.49 km2 closest to the median of all estimates. Although Hainan gibbon spatial requirements are relatively large for gibbons, our new estimates are smaller than previous estimates used to explain the species’ limited recovery, suggesting that habitat availability may be less important in limiting population growth. We argue that other ecological, genetic, and/or anthropogenic factors are more likely to constrain Hainan gibbon recovery, and conservation attention should focus on elucidating and managing these factors

    Leak-before-break: Global perspectives and procedures

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    Structural integrity of components containing fluids is critical for economic, environmental and safety issues. Any risk of catastrophic failure, in the form of either brittle or ductile manner, is not acceptable across the industries. Consequently, many efforts have been invested in the structural integrity aspect to improve the assessment methodologies. One of the ways to aid the decision whether or not to live with the defect is through the demonstration of Leak-Before-Break (LBB). LBB which is a well-established practice in the nuclear industry, albeit as a defence-in-depth argument or to justify the elimination of pipe whip restraints, also finds its applicability in other industries. A review of the available procedures, their associated limitations and the research carried out in the last thirty years is presented in this paper. Application of this concept within non-nuclear industries is also discussed

    Swept Under the Rug? A Historiography of Gender and Black Colleges

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    Drone defense system architecture for U.S. Navy strategic facilities

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    Systems Engineering Capstone Project ReportSmall, commercially available unmanned aerial systems (UAS) are an emergent threat to Navy continental U.S. (CONUS) military facilities. There are many counter unmanned aerial system (C-UAS) tools focused on neutralization, and many sensors in place. A system-of-systems, defense-in-depth approach to C-UAS requires a central system to connect these new and existing systems. The central system uses data fusion and threat evaluation and weapons assignment (TEWA) to properly address threats. This report follows a systems engineering process to develop a software architecture for that central system, beginning with a requirements analysis, a functional baseline, and the resulting module allocation. A series of simulations in ExtendSim derives the performance requirements by examining the overall C-UAS scenario with currently available technology. Through a sensitivity analysis, the simulation shows that effective engagement range (combination of initial target range, detection range and neutralization range) is the dominant factor driving response time. The architecture modeled in Innoslate provides a discrete event simulation for system performance expectations.http://archive.org/details/dronedefensesyst1094556172Approved for public release; distribution is unlimited

    The impact of national guidelines on the waiting list for colonoscopy: a quantitative clinical audit

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    Objective: to assess the compliance of the surveillance colonoscopy waiting list with ACPGBI/BSG guidelines for colonoscopy follow-up and to measure the impact of adjusting referrals to be inline with the guidelines.Design and Setting: this is a quantitative five-stage clinical audit cycle involving a large patient cohort from the Kent and Medway Cancer Network, which includes seven hospitals across four NHS Hospital Trusts and an estimated population of 1.8 million.Participants: 3020 patients were waiting for a surveillance colonoscopy. Their notes were reviewed and the indications for colonoscopy were compared with the ACPGBI/BSG 2002 guidelines.Interventions: those patients whose referral to the surveillance colonoscopy waiting list was not found to be compliant were adjusted to be inline with the guidelines.Main outcome measures: the impact of adjusting the surveillance colonoscopy waiting list on the diagnostic colonoscopy service was assessed by measuring the average waiting times for a colonoscopy before and after the intervention.Results: around 22% (n = 664) of surveillance colonoscopy referrals were inline with the guidelines, 51% (n = 1540) could be cancelled from the list and 27% (n = 816) could be given a new date. Implementing these recommendations reduced the average wait for a diagnostic colonoscopy from 76.8 to 56.0 days (P = 0.0022).Conclusion: following guidelines for surveillance colonoscopy can reduce waiting times for diagnostic colonoscopy. This allows a faster patient journey for diagnostic colonoscopy and a uniform plan for duration and frequency of surveillance colonoscopy. However, this action promoted serious debate on the social, moral and ethical issue

    Age and growth of franciscana Pontoporia blainvillei (Cetacea: Pontoporiidae) incidentally caught off southern Brazil and northern Argentina

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    Age and length data of 291 franciscana dolphins (Pontoporia blainvillei)incidentally captured on the coast of Rio Grande do Sul State (RS), southern Brazil, were used to fit growth curves using Gompertz and Von Bertalanffy growth models. A small sample of franciscanas (N ÂŒ 35) from Buenos Aires Province (BA), Argentina, were used to see if there are apparent growth differences between the populations. Male and female franciscana samples from both areas were primarily (78–85%) ,4 years of age. The Von Bertalanffy growth model with a data set that excluded animals ,1 year of age provided the best fit to data. Based on this model, dolphins from the RS population reached asymptotic length at 136.0 cm and 158.4 cm,for males and females, respectively. No remarkable differences were observed in the growth trajectories of males and females between the RS and BA populations

    Identification of the nik Gene Cluster of Brucella suis: Regulation and Contribution to Urease Activity

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    Analysis of a Brucella suis 1330 gene fused to a gfp reporter, and identified as being induced in J774 murine macrophage-like cells, allowed the isolation of a gene homologous to nikA, the first gene of the Escherichia coli operon encoding the specific transport system for nickel. DNA sequence analysis of the corresponding B. suis nik locus showed that it was highly similar to that of E. coli except for localization of the nikR regulatory gene, which lies upstream from the structural nikABCDE genes and in the opposite orientation. Protein sequence comparisons suggested that the deduced nikABCDE gene products belong to a periplasmic binding protein-dependent transport system. The nikA promoter-gfp fusion was activated in vitro by low oxygen tension and metal ion deficiency and was repressed by NiCl(2) excess. Insertional inactivation of nikA strongly reduced the activity of the nickel metalloenzyme urease, which was restored by addition of a nickel excess. Moreover, the nikA mutant of B. suis was functionally complemented with the E. coli nik gene cluster, leading to the recovery of urease activity. Reciprocally, an E. coli strain harboring a deleted nik operon recovered hydrogenase activity by heterologous complementation with the B. suis nik locus. Taking into account these results, we propose that the nik locus of B. suis encodes a nickel transport system. The results further suggest that nickel could enter B. suis via other transport systems. Intracellular growth rates of the B. suis wild-type and nikA mutant strains in human monocytes were similar, indicating that nikA was not essential for this step of infection. We discuss a possible role of nickel transport in maintaining enzymatic activities which could be crucial for survival of the bacteria under the environmental conditions encountered within the host
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