1,547 research outputs found

    Turbidity-Based Sediment Monitoring in Northern Thailand: Hysteresis, Variability, and Uncertainty

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    Annual total suspended solid (TSS) loads in the Mae Sa River in northern Thailand, determined with an automated, turbidity-based monitoring approach, were approximately 62,000, 33,000, and 14,000 Mg during the three years of observation. These loads were equivalent to basin yields of 839 (603-1170), 445 (217-462), and 192 (108-222) Mg km-2 for the 74.16-km2 catchment during 2006, 2007, and 2008, respectively. The yearly uncertainty ranges indicate our loads may be underestimated by 38-43% or overestimated by 28-33%. In determining the annual loads, discharge (Q) and turbidity (T) values were compared against 333 hand-sampled total suspended solid concentrations (TSS) measured during 18 runoff events and other flow conditions across the three-year period. Annual rainfall varied from 1632 to 1934 mm; and catchment runoff coefficients (annual runoff/annual rainfall) ranged from 0.25 to 0.41. Measured TSS ranged from 8-15,900 mg l-1; the low value was associated with dry-season base flow; the latter, a wet-season storm. Storm size and location played an important role in producing clockwise, anticlockwise, and complex hysteresis effects in the Q-TSS relationship. Turbidity alone was a good estimator for turbidity ranges of roughly 10-2800 NTU (or concentrations approximately 25-4000 mg l-1). However, owing to hysteresis and high sediment concentrations that surpass the detection limits of the turbidity sensor during many annual storms, TSS was estimated best using a complex multiple regression equation based on high/low ranges of turbidity and Q as independent variables. Turbidity was not a good predictor of TSS fractions \u3e 2000 μm. Hysteresis in the monthly Q-TSS relationship was generally clockwise over the course of the monsoon season, but infrequent large dry-season storms disrupted the pattern in some years. The large decrease in annual loads during the study was believed to be related to depletion of fine sediment delivered to the stream by several landslides occurring the year prior to the study. The study indicated the importance of monitoring Q and turbidity at fine resolutions (e.g., sub-hourly) to capture the TSS dynamics and to make accurate load estimations in this flashy headwater stream where hysteresis in the Q-TSS signature varied at several time scales

    Opening the Range: Reforms to Allow Markets for Voluntary Conservation on Federal Grazing Lands

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    For nearly a century, the federal government has authorized ranchers to graze livestock on large areas of federal lands in the western United States. Federal-land grazing has generated substantial conflict in recent decades, as conservation interests and others have lobbied and litigated against what they view as inappropriate and destructive use of federal lands. This has produced a predictable backlash among ranching interests, including efforts to roll back the regulations relied on by environmental litigants and aggressive confrontations with federal regulators. But such conflict is not inevitable. Competing demands on these lands can be resolved through voluntary means and positive incentives for conservation practices, as they often are on private lands. On public lands, however, federal law erects substantial barriers to this market approach by imposing use-it-or-lose-it rules on federal grazing permits. In this Article, we discuss those barriers and offer statutory and regulatory reforms that would overcome them while facilitating markets for conservation on federal grazing lands

    A fire driven shift from forest to non-forest: evidence for alternative stable states?

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    We test the validity of applying the alternative stable state paradigm to account for the landscape-scale forest/non-forest mosaic that prevails in temperate Tasmania, Australia. This test is based on fine-scale pollen, spore, and charcoal analyses of sediments located within a small patch of non-forest vegetation surrounded by temperate forest. Following nearly 500 years of forest dominance at the site, a catastrophic fire drove an irreversible shift from a forested Cyperaceae-Sphagnum wetland to a non-forested Restionaceae wetland at ca. 7000 calibrated (cal) yr BP. Persistence of the non-forest/Restionaceae vegetation state over 7000 years, despite long fire-free intervals, implies that fire was not essential for the maintenance of the non-forest state. We propose that reduced interception and transpiration of the non-forest state resulted in local waterlogging, presenting an eco-hydrological barrier to forest reestablishment over the succeeding 7000 years. We further contend that the rhizomatous nature of the non-forest species presented a reinforcing eco-physical barrier to forest development. Our results satisfy a number of criteria for consideration as an example of a switch between alternative stable states, including different origin and maintenance pathways, and they provide insights into the role of threshold dynamics and hysteresis in forest-non-forest transitions

    Making it stick: The secret to developing a data-driven culture

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    Big data and analytics has been recognized as fundamental to an organization’s success has consistently identified as one of top 10 Workforce Trends in recent years. One of the final steps in an analytics or applied research project is deployment where a solution is integrated into business practices. Without cultural acceptance, however, organizations risk missing out on the full impact that data and evidence-based practices can deliver. Even with data and analytics solutions deployed in business procedures, employees may still make decisions based on hunches and instinct. In order to harness the full potential of data analytics, organizations need to develop a culture that moves from “What do we think?” to “What do we know?”. Cultural change can be one of the most difficult things to effect in an organization, and transitioning to a data-driven culture has numerous challenges. Presenters will discuss strategies for gaining organizational commitment to data-driven decision-making, by increasing employee understanding of the value of evidence-based practices, and how data and analytics can be applied to decision-making

    Disability and the Dancing Body:A Symposium on Ownership, Identity and Difference in Dance

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    Acknowledgements We would like to thank Siobhan Davies Studios, which was aptly described by one of our participants as “a Cathedral for contemporary dance”, for hosting the symposium and assisting us on the day. We would also like to thank the staff at the Centre for Dance Research (C-Dare) at Coventry University for their support during the day. We would also, of course, like to thank the AHRC for its kind support of InVisible Difference.Peer reviewedPublisher PD

    The Extratropical Transition of Tropical Cyclones. Part I: Cyclonic Evolution and Direct Impacts

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    Extratropical transition (ET) is the process by which a tropical cyclone, upon encountering a baroclinic environment and reduced sea surface temperature at higher latitudes, transforms into an extratropical cyclone. This process is influenced by, and influences, phenomena from the tropics to the midlatitudes and from the meso- to the planetary scales to extents that vary between individual events. Motivated in part by recent high-impact and/or extensively observed events such as North Atlantic Hurricane Sandy in 2012 and western North Pacific Typhoon Sinlaku in 2008, this review details advances in understanding and predicting ET since the publication of an earlier review in 2003. Methods for diagnosing ET in reanalysis, observational, and model-forecast datasets are discussed. New climatologies for the eastern North Pacific and southwest Indian Oceans are presented alongside updates to western North Pacific and North Atlantic Ocean climatologies. Advances in understanding and, in some cases, modeling the direct impacts of ET-related wind, waves, and precipitation are noted. Improved understanding of structural evolution throughout the transformation stage of ET fostered in large part by novel aircraft observations collected in several recent ET events is highlighted. Predictive skill for operational and numerical model ET-related forecasts is discussed along with environmental factors influencing posttransition cyclone structure and evolution. Operational ET forecast and analysis practices and challenges are detailed. In particular, some challenges of effective hazard communication for the evolving threats posed by a tropical cyclone during and after transition are introduced. This review concludes with recommendations for future work to further improve understanding, forecasts, and hazard communication

    Prevention of problem gambling: Lessons learned from two Alberta programs

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    National Association for Gambling Studies (Australia) 2003 Conference ProceedingsThe development of effective problem gambling prevention programs is in its infancy. The present paper discusses results of randomized control trials of two programs that have been implemented in Alberta, Canada. The first is a 10 session program delivered to several classes of university students taking Introductory Statistics. This program focused primarily on teaching the probabilities associated with gambling and included several hands-on demonstrations of typical casino table games. The second is a 5 session program delivered to high school students at several sites in southern Alberta. This program was more comprehensive, containing information and exercises on the nature of gambling and problem gambling, gambling fallacies, gambling odds, decisionmaking, coping skills, and social problem-solving skills. Data concerning gambling attitudes, gambling fallacies and gambling behaviour at 3 and 6-months postintervention are presented. The findings of these studies are somewhat counter-intuitive and have important implications for the design of effective prevention programs.Alberta Gaming Research Institut

    Membrane plasmalogen composition and cellular cholesterol regulation: a structure activity study

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    <p>Abstract</p> <p>Background</p> <p>Disrupted cholesterol regulation leading to increased circulating and membrane cholesterol levels is implicated in many age-related chronic diseases such as cardiovascular disease (CVD), Alzheimer's disease (AD), and cancer. <it>In vitro </it>and <it>ex vivo </it>cellular plasmalogen deficiency models have been shown to exhibit impaired intra- and extra-cellular processing of cholesterol. Furthermore, depleted brain plasmalogens have been implicated in AD and serum plasmalogen deficiencies have been linked to AD, CVD, and cancer.</p> <p>Results</p> <p>Using plasmalogen deficient (NRel-4) and plasmalogen sufficient (HEK293) cells we investigated the effect of species-dependent plasmalogen restoration/augmentation on membrane cholesterol processing. The results of these studies indicate that the esterification of cholesterol is dependent upon the amount of polyunsaturated fatty acid (PUFA)-containing ethanolamine plasmalogen (PlsEtn) present in the membrane. We further elucidate that the concentration-dependent increase in esterified cholesterol observed with PUFA-PlsEtn was due to a concentration-dependent increase in sterol-O-acyltransferase-1 (SOAT1) levels, an observation not reproduced by 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase inhibition.</p> <p>Conclusion</p> <p>The present study describes a novel mechanism of cholesterol regulation that is consistent with clinical and epidemiological studies of cholesterol, aging and disease. Specifically, the present study describes how selective membrane PUFA-PlsEtn enhancement can be achieved using 1-alkyl-2-PUFA glycerols and through this action reduce levels of total and free cholesterol in cells.</p
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