288 research outputs found

    Automated surveillance of 911 call data for detection of possible water contamination incidents

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    <p>Abstract</p> <p>Background</p> <p>Drinking water contamination, with the capability to affect large populations, poses a significant risk to public health. In recent water contamination events, the impact of contamination on public health appeared in data streams monitoring health-seeking behavior. While public health surveillance has traditionally focused on the detection of pathogens, developing methods for detection of illness from fast-acting chemicals has not been an emphasis.</p> <p>Methods</p> <p>An automated surveillance system was implemented for Cincinnati's drinking water contamination warning system to monitor health-related 911 calls in the city of Cincinnati. Incident codes indicative of possible water contamination were filtered from all 911 calls for analysis. The 911 surveillance system uses a space-time scan statistic to detect potential water contamination incidents. The frequency and characteristics of the 911 alarms over a 2.5 year period were studied.</p> <p>Results</p> <p>During the evaluation, 85 alarms occurred, although most occurred prior to the implementation of an additional alerting constraint in May 2009. Data were available for analysis approximately 48 minutes after calls indicating alarms may be generated 1-2 hours after a rapid increase in call volume. Most alerts occurred in areas of high population density. The average alarm area was 9.22 square kilometers. The average number of cases in an alarm was nine calls.</p> <p>Conclusions</p> <p>The 911 surveillance system provides timely notification of possible public health events, but did have limitations. While the alarms contained incident codes and location of the caller, additional information such as medical status was not available to assist validating the cause of the alarm. Furthermore, users indicated that a better understanding of 911 system functionality is necessary to understand how it would behave in an actual water contamination event.</p

    Biogeochemical implications of biodiversity and community structure across multiple coastal ecosystems

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    Small-scale experiments and theory suggest that ecological functions provided by communities become more stable with increased species richness. Whether these patterns manifest at regional spatial scales and within species-rich communities (e.g., coral reefs) is largely unknown. We quantified five biogeochemical processes, and an aggregate measure of multifunctionality, in species-rich coastal fish communities to test three questions: (1) Do previously predicted biodiversity-ecosystem-function relationships hold across large spatial scales and in highly diverse communities? (2) Can additional covariates of community structure improve these relationships? (3) What is the role of community biomass and functional group diversity in maintaining biogeochemical processes under various scenarios of species loss across ecosystem types? These questions were tested across a large regional gradient of coral reef, mangrove and seagrass ecosystems. Statistical models demonstrated that species richness and the mean maximum body size per species strongly predicted biogeochemical processes in all ecosystem types, but functional group diversity was only a weak predictor. Simulating three scenarios of species loss demonstrated that conserving community biomass alone increased the ability for communities to maintain ecosystem processes. Multifunctionality of biogeochemical processes was maintained least in simulations that conserved biomass and community structure, underscoring the relative lack of importance of community structure in maintaining multiple simultaneous ecosystem functions in this system. Findings suggest that conserving community biomass alone may be sufficient to sustain certain biogeochemical processes, but when considering conservation of multiple simultaneous biogeochemical processes, management efforts should focus first on species richness

    Individual Behavior Drives Ecosystem Function and the Impacts of Harvest

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    Current approaches for biodiversity conservation and management focus on sustaining high levels of diversity among species to maintain ecosystem function. We show that the diversity among individuals within a single population drives function at the ecosystem scale. Specifically, nutrient supply from individual fish differs from the population average \u3e80% of the time, and accounting for this individual variation nearly doubles estimates of nutrients supplied to the ecosystem. We test how management (i.e., selective harvest regimes) can alter ecosystem function and find that strategies targeting more active individuals reduce nutrient supply to the ecosystem up to 69%, a greater effect than body size–selective or nonselective harvest. Findings show that movement behavior at the scale of the individual can have crucial repercussions for the functioning of an entire ecosystem, proving an important challenge to the species-centric definition of biodiversity if the conservation and management of ecosystem function is a primary goal

    Specific Electrogram Characteristics Identify the Extra-Pulmonary Vein Arrhythmogenic Sources of Persistent Atrial Fibrillation – Characterization of the Arrhythmogenic Electrogram Patterns During Atrial Fibrillation and Sinus Rhythm

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    Identification of atrial sites that perpetuate atrial fibrillation (AF), and ablation thereof terminates AF, is challenging. We hypothesized that specific electrogram (EGM) characteristics identify AF-termination sites (AFTS). Twenty-one patients in whom low-voltage-guided ablation after pulmonary vein isolation terminated clinical persistent AF were included. Patients were included if short RF-delivery for <8sec at a given atrial site was associated with acute termination of clinical persistent AF. EGM-characteristics at 21 AFTS, 105 targeted sites without termination and 105 non-targeted control sites were analyzed. Alteration of EGM-characteristics by local fibrosis was evaluated in a three-dimensional high resolution (100 µm)-computational AF model. AFTS demonstrated lower EGM-voltage, higher EGM-cycle-length-coverage, shorter AF-cycle-length and higher pattern consistency than control sites (0.49 ± 0.39 mV vs. 0.83 ± 0.76 mV, p < 0.0001; 79 ± 16% vs. 59 ± 22%, p = 0.0022; 173 ± 49 ms vs. 198 ± 34 ms, p = 0.047; 80% vs. 30%, p < 0.01). Among targeted sites, AFTS had higher EGM-cycle-length coverage, shorter local AF-cycle-length and higher pattern consistency than targeted sites without AF-termination (79 ± 16% vs. 63 ± 23%, p = 0.02; 173 ± 49 ms vs. 210 ± 44 ms, p = 0.002; 80% vs. 40%, p = 0.01). Low voltage (0.52 ± 0.3 mV) fractionated EGMs (79 ± 24 ms) with delayed components in sinus rhythm (‘atrial late potentials’, respectively ‘ALP’) were observed at 71% of AFTS. EGMs recorded from fibrotic areas in computational models demonstrated comparable EGM-characteristics both in simulated AF and sinus rhythm. AFTS may therefore be identified by locally consistent, fractionated low-voltage EGMs with high cycle-length-coverage and rapid activity in AF, with low-voltage, fractionated EGMs with delayed components/ ‘atrial late potentials’ (ALP) persisting in sinus rhythm

    Anthropogenic versus fish‐derived nutrient effects on seagrass community structure and function

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    Humans are altering nutrient dynamics through myriad pathways globally. Concurrent with the addition of nutrients via municipal, industrial, and agricultural sources, widespread consumer exploitation is changing consumer‐mediated nutrient dynamics drastically. Thus, altered nutrient dynamics can occur through changes in the supply of multiple nutrients, as well as through changes in the sources of these nutrients. Seagrass ecosystems are heavily impacted by human activities, with highly altered nutrient dynamics from multiple causes. We simulate scenarios of altered nutrient supply and ratios, nitrogen:phosphorus (N:P), from two nutrient sources in seagrass ecosystems: anthropogenic fertilizer and fish excretion. In doing so we tested expectations rooted in ecological theory that suggest the importance of resource dynamics for predicting primary producer dynamics. Ecosystem functions were strongly altered by artificial fertilizer (e.g., seagrass growth increased by as much as 140%), whereas plant/algae community structure was most affected by fish‐mediated nutrients or the interaction of both treatments (e.g., evenness increased by ~140% under conditions of low fish nutrients and high anthropogenic nutrients). Interactions between the nutrient sources were found for only two of six response variables, and the ratio of nutrient supply was the best predictor for only one response. These findings show that seagrass structure and function are well predicted by supply of a single nutrient (either N or P). Importantly, no single nutrient best explained the majority of responses—measures of community structure were best explained by the primary limiting nutrient to this system (P), whereas measures of growth and density of the dominant producer in the system were best explained by N. Thus, while our findings support aspects of theoretical expectations, the complexity of producer community responses belies broad generalities, underscoring the need to manage for multiple simultaneous nutrients in these imperiled coastal ecosystems.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145341/1/ecy2388_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145341/2/ecy2388-sup-0003-AppendixS3.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145341/3/ecy2388-sup-0005-AppendixS5.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145341/4/ecy2388-sup-0006-AppendixS6.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145341/5/ecy2388-sup-0001-AppendixS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145341/6/ecy2388-sup-0002-AppendixS2.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145341/7/ecy2388.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145341/8/ecy2388-sup-0004-AppendixS4.pd

    Rewiring coral: Anthropogenic nutrients shift diverse coral–symbiont nutrient and carbon interactions toward symbiotic algal dominance

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    Improving coral reef conservation requires heightened understanding of the mechanisms by which coral cope with changing environmental conditions to maintain optimal health. We used a long‐term (10 month) in situ experiment with two phylogenetically diverse scleractinians (Acropora palmata and Porites porites) to test how coral–symbiotic algal interactions changed under real‐world conditions that were a priori expected to be beneficial (fish‐mediated nutrients) and to be harmful, but non‐lethal, for coral (fish + anthropogenic nutrients). Analyzing nine response variables of nutrient stoichiometry and stable isotopes per coral fragment, we found that nutrients from fish positively affected coral growth, and moderate doses of anthropogenic nutrients had no additional effects. While growing, coral maintained homeostasis in their nutrient pools, showing tolerance to the different nutrient regimes. Nonetheless, structural equation models revealed more nuanced relationships, showing that anthropogenic nutrients reduced the diversity of coral–symbiotic algal interactions and caused nutrient and carbon flow to be dominated by the symbiont. Our findings show that nutrient and carbon pathways are fundamentally “rewired” under anthropogenic nutrient regimes in ways that could increase corals’ susceptibility to further stressors. We hypothesize that our experiment captured coral in a previously unrecognized transition state between mutualism and antagonism. These findings highlight a notable parallel between how anthropogenic nutrients promote symbiont dominance with the holobiont, and how they promote macroalgal dominance at the coral reef scale. Our findings suggest more realistic experimental conditions, including studies across gradients of anthropogenic nutrient enrichment as well as the incorporation of varied nutrient and energy pathways, may facilitate conservation efforts to mitigate coral loss.We provide a long‐term field experiment to test the implications of different nutrient sources, fish excretion and moderate levels of anthropogenic nutrients, for coral health and coral–symbiont interactions. Our study identifies a potentially novel "transition state" whereby despite maintaining high growth rates and creating no apparent negative external effects, anthropogenic nutrient enrichment drives coral–algal interactions to be dominated by the algal symbiont—that is, increased prominence of energy and nutrient flow from the algal symbiont under conditions of Fish + anthropogenic nutrients (NPK) in the figure. We hypothesize that this “rewiring” of the coral–symbiont interactions may render the coral more vulnerable to additional stressors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162733/2/gcb15230_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162733/1/gcb15230.pd

    Interplay among critical temperature, hole content, and pressure in the cuprate superconductors

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    Within a BCS-type mean-field approach to the extended Hubbard model, a nontrivial dependence of T_c on the hole content per unit CuO_2 is recovered, in good agreement with the celebrated non-monotonic universal behaviour at normal pressure. Evaluation of T_c at higher pressures is then made possible by the introduction of an explicit dependence of the tight-binding band and of the carrier concentration on pressure P. Comparison with the known experimental data for underdoped Bi2212 allows to single out an `intrinsic' contribution to d T_c / d P from that due to the carrier concentration, and provides a remarkable estimate of the dependence of the inter-site coupling strength on the lattice scale.Comment: REVTeX 8 pages, including 5 embedded PostScript figures; other required macros included; to be published in Phys. Rev. B (vol. 54

    Anomalous electronic susceptibility in Bi2Sr2CuO6+d and comparison with other overdoped cuprates

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    We report magnetic susceptibility performed on overdoped Bi2Sr2CuO6+d powders as a function of oxygen doping d and temperature T. The decrease of the spin susceptibility with increasing T is confirmed. At sufficient high temperature, the spin susceptibility Chi_s presents an unusual linear temperature dependence Chi_s ~ Chi_s0 -Chi_1 T. Moreover, a linear correlation between Chi_1 and Chi_s0 for increasing hole concentration is displayed. A temperature Tchi, independent of hole doping characterizes this scaling. Comparison with other cuprates of the literature(LSCO, Tl-2201 and Bi-2212), over the same overdoped range, shows similarities with above results. These non conventional metal features will be discussed in terms of a singular narrow-band structure.Comment: 16 pages, 4 figure

    Sagopilone (ZK-EPO, ZK 219477) for recurrent glioblastoma. A phase II multicenter trial by the European Organisation for Research and Treatment of Cancer (EORTC) Brain Tumor Group

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    Background: Sagopilone (ZK 219477), a lipophylic and synthetic analog of epothilone B, that crosses the blood-brain barrier has demonstrated preclinical activity in glioma models. Patients and methods: Patients with first recurrence/progression of glioblastoma were eligible for this early phase II and pharmacokinetic study exploring single-agent sagopilone (16 mg/m2 over 3 h every 21 days). Primary end point was a composite of either tumor response or being alive and progression free at 6 months. Overall survival, toxicity and safety and pharmacokinetics were secondary end points. Results: Thirty-eight (evaluable 37) patients were included. Treatment was well tolerated, and neuropathy occurred in 46% patients [mild (grade 1) : 32%]. No objective responses were seen. The progression-free survival (PFS) rate at 6 months was 6.7% [95% confidence interval (CI) 1.3-18.7], the median PFS was just over 6 weeks, and the median overall survival was 7.6 months (95% CI 5.3-12.3), with a 1-year survival rate of 31.6% (95% CI 17.7-46.4). Maximum plasma concentrations were reached at the end of the 3-h infusion, with rapid declines within 30 min after termination. Conclusions: No evidence of relevant clinical antitumor activity against recurrent glioblastoma could be detected. Sagopilone was well tolerated, and moderate-to-severe peripheral neuropathy was observed in despite prolonged administratio
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