356 research outputs found

    Were Multiple Stressors a \u27Perfect Storm\u27 for Northern Gulf of Mexico Bottlenose Dolphins (Tursiops truncatus) in 2011?

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    An unusual number of near term and neonatal bottlenose dolphin (Tursiops truncatus) mortalities occurred in the northern Gulf of Mexico (nGOM) in 2011, during the first calving season after two well documented environmental perturbations; sustained cold weather in 2010 and the Deepwater Horizon oil spill (DWHOS). Preceding the stranding event, large volumes of cold freshwater entered the nGOM due to unusually large snowmelt on the adjacent watershed, providing a third potential stressor. We consider the possibility that this extreme cold and freshwater event contributed to the pattern of perinatal dolphin strandings along the nGOM coast. During the 4-month period starting January 2011, 186 bottlenose dolphins, including 46% perinatal calves (nearly double the percentage for the same time period from 2003-2010) washed ashore from Louisiana to western Florida. Comparison of the frequency distribution of strandings to flow rates and water temperature at a monitoring buoy outside Mobile Bay, Alabama (the 4th largest freshwater drainage in the U. S.) and along the nGOM coast showed that dolphin strandings peaked in Julian weeks 5, 8, and 12 (February and March), following water temperature minima by 2-3 weeks. If dolphin condition was already poor due to depleted food resources, bacterial infection, or other factors, it is plausible that the spring freshet contributed to the timing and location of the unique stranding event in early 2011. These data provide strong observational evidence to assess links between the timing of the DWHOS, other local environmental stressors, and mortality of a top local predator. Targeted analyses of tissues from stranded dolphins will be essential to define a cause of death, and our findings highlight the importance of considering environmental data along with biological samples to interpret stranding patterns during and after an unusual mortality event

    Probabilistic Analysis of Facility Location on Random Shortest Path Metrics

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    The facility location problem is an NP-hard optimization problem. Therefore, approximation algorithms are often used to solve large instances. Such algorithms often perform much better than worst-case analysis suggests. Therefore, probabilistic analysis is a widely used tool to analyze such algorithms. Most research on probabilistic analysis of NP-hard optimization problems involving metric spaces, such as the facility location problem, has been focused on Euclidean instances, and also instances with independent (random) edge lengths, which are non-metric, have been researched. We would like to extend this knowledge to other, more general, metrics. We investigate the facility location problem using random shortest path metrics. We analyze some probabilistic properties for a simple greedy heuristic which gives a solution to the facility location problem: opening the κ\kappa cheapest facilities (with κ\kappa only depending on the facility opening costs). If the facility opening costs are such that κ\kappa is not too large, then we show that this heuristic is asymptotically optimal. On the other hand, for large values of κ\kappa, the analysis becomes more difficult, and we provide a closed-form expression as upper bound for the expected approximation ratio. In the special case where all facility opening costs are equal this closed-form expression reduces to O(ln(n)4)O(\sqrt[4]{\ln(n)}) or O(1)O(1) or even 1+o(1)1+o(1) if the opening costs are sufficiently small.Comment: A preliminary version accepted to CiE 201

    Emerging IT risks: insights from German banking

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    How do German banks manage the emerging risks stemming from IT innovations such as cyber risk? With a focus on process, roles and responsibilities, field data from ten banks participating in the 2014 ECB stress test were collected by interviewing IT managers, risk managers and external experts. Current procedures for handling emerging risks in German banks were identified from the interviews and analysed, guided by the extant literature. A clear gap was found between enterprise risk management (ERM) as a general approach to risks threatening firms’ objectives and ERM’s neglect of emerging risks, such as those associated with IT innovations. The findings suggest that ERM should be extended towards the collection and sharing of knowledge to allow for an initial understanding and description of emerging risks, as opposed to the traditional ERM approach involving estimates of impact and probability. For example, as cyber risks emerge from an IT innovation, the focus may need to switch towards reducing uncertainty through knowledge acquisition. Since individual managers seldom possess all relevant knowledge of an IT innovation, various stakeholders may need to be involved to exploit their expertise

    Review and Evaluation of the J100â 10 Risk and Resilience Management Standard for Water and Wastewater Systems

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    Risk analysis standards are often employed to protect critical infrastructures, which are vital to a nation’s security, economy, and safety of its citizens. We present an analysis framework for evaluating such standards and apply it to the J100â 10 risk analysis standard for water and wastewater systems. In doing so, we identify gaps between practices recommended in the standard and the state of the art. While individual processes found within infrastructure risk analysis standards have been evaluated in the past, we present a foundational review and focus specifically on water systems. By highlighting both the conceptual shortcomings and practical limitations, we aim to prioritize the shortcomings needed to be addressed. Key findings from this study include (1) risk definitions fail to address notions of uncertainty, (2) the sole use of â worst reasonable caseâ assumptions can lead to mischaracterizations of risk, (3) analysis of risk and resilience at the threatâ asset resolution ignores dependencies within the system, and (4) stakeholder values need to be assessed when balancing the tradeoffs between risk reduction and resilience enhancement.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154262/1/risa13421_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154262/2/risa13421.pd

    Risk response strategies for collaborative university-industry R&D funded programs

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    Universities are centers of knowledge in our societies and their role when it comes to innovation has become more important over the years. Companies have several reasons to engage in research collaborations with universities, namely to gain access to innovative technologies. University-Industry R&D collaborations are expected to play an important role in regional economies, and to fulfill the industry’s demand for innovative products, technologies and processes. However, the knowledge on what are the potential risks resulting from these collaborations and the risk response strategies to reduce the negative risk impacts and to enhance positive risk impacts is still limited. Thus, this paper aims to fill the gap in literature when it comes to risk identification and risk responses’ planning, by identifying, based on a case study analysis, 19 potential risks and 53 potential risk response strategies.INCT-EN - Instituto Nacional de Ciência e Tecnologia para Excitotoxicidade e Neuroproteção(SFRH/BPD/111033/2015
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