87 research outputs found

    The distribution of ctenophora in the Patuxent estuary during the summer of 1958

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    Investigation of Ctenophores in the Chesapeake Bay area, includes some aspects of their life history, growth, reproduction, feeding and food habits, abundance and distribution. the purpose of the entire project is to supplement and add to the biological knowledge and understanding of ctenophores as a group and of the several individual species found int he area to be studied. Includes possible factors involved and implications also being looked at. (PDF contains 33 pages

    How Can We Best Test The Effects Of Pollutants And Changes On The Animals And Plants Of Chesapeake Bay?

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    The animals and plants of the Bay, and the processes in which they are involved, are the basis for almost every use and desirable quality of the Bay. They provide both commercial and recreational fisheries, assimilate some quantities of wastes, contribute to esthetic quality, provide a favorable environment for many birds and mammals and feed all of the species which are used by man. However, the biota are directly or indirectly affected by many human activities - by maritime transport, recreational activities, agricultural production, waste discharges, domestic development, engineering activity, and other land-based activities. Therefore, the ultimate and most important question to be considered in evaluating any new pollutant or proposed environmental modification is - What effect will it have on the biota?https://scholarworks.wm.edu/vimsbooks/1175/thumbnail.jp

    A partial bibliography of the Genus Callinectes

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    Also part of series: Virginia Fisheries Laboratory special scientific report ; no. 8

    Response to freshwater inflow in the Rappahannock Estuary, Virginia : Operation HIFLO \u2778

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    More sediment, nutrients and pollutants are discharged into an estuary during a few days of flood inflow than during many months or years of average inflow (Meade, 1972; Schubel, 1977), but few observations document the sedimentary response of an estuary to high freshwater inflow. Such inflows are usually unexpected and estuarine water charact~ristics change too rapidly to permit systematic measurements. Moreover, the expenditure of effort and number of sampling vessels required on short notice is beyond the resources of a single research group or institute. Yet, freshwater inflow observations are a key to improving water quality; especially to ameliorate the effects of high turbidity, depleted oxygen and low salinity which can cause oyster motalities (Zaborski and Haven, 1980). Many si9nificant ecological effects are noted by Snedakar, et al., 1977. Exceptional sediment deposition shoals shipping channels, fills boat basins, and blanke~ts oyster grounds. Suspended sediments adsorb toxic contaminates, nutrients and organic matter, and thus can affect plant production and the distribution of shellfish, plants and other life. The HIFLO experiment was planned to observe and evaluate the response of an estuary to high freshwater inflow and high influx of suspended sediment. Of special interest are the questions: How far seaward does the sediment load from an event go before settling to the bed? How do the hydrodynamic conditions for sediment transport change? What is the sequence of estuarine processes triggered by a river flood

    How Should Research And Monitoring Be Integrated?

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    Scientific knowledge of Chesapeake Bay and tidal tributaries has accumulated over many years beginning mostly with descriptive surveys prior to the 1960\u27s and 1970\u27s and evolving towards a coupling of monitoring and research in recent years. This essay discusses the need to more fully couple monitoring and research efforts in the Bay system because such a union of efforts is argued to be the most effective way to assess gross trends in the health of the system (monitoring) and to understand the basic forces causing these trends (research). We argue that together they provide part of the framework necessary for effective management of the living resources of the bay region.https://scholarworks.wm.edu/vimsbooks/1176/thumbnail.jp

    Financing Direct Democracy: Revisiting the Research on Campaign Spending and Citizen Initiatives

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    The conventional view in the direct democracy literature is that spending against a measure is more effective than spending in favor of a measure, but the empirical results underlying this conclusion have been questioned by recent research. We argue that the conventional finding is driven by the endogenous nature of campaign spending: initiative proponents spend more when their ballot measure is likely to fail. We address this endogeneity by using an instrumental variables approach to analyze a comprehensive dataset of ballot propositions in California from 1976 to 2004. We find that both support and opposition spending on citizen initiatives have strong, statistically significant, and countervailing effects. We confirm this finding by looking at time series data from early polling on a subset of these measures. Both analyses show that spending in favor of citizen initiatives substantially increases their chances of passage, just as opposition spending decreases this likelihood

    Cognitive Effects of Risperidone in Children with Autism and Irritable Behavior

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    Objective: The objective of this research was to explore the effects of risperidone on cognitive processes in children with autism and irritable behavior. Method: Thirty-eight children, ages 5-17 years with autism and severe behavioral disturbance, were randomly assigned to risperidone (0.5 to 3.5 mg/day) or placebo for 8 weeks. This sample of 38 was a subset of 101 subjects who participated in the clinical trial; 63 were unable to perform the cognitive tasks. A double-blind placebo-controlled parallel groups design was used. Dependent measures included tests of sustained attention, verbal learning, hand-eye coordination, and spatial memory assessed before, during, and after the 8-week treatment. Changes in performance were compared by repeated measures ANOVA. Results: Twenty-nine boys and 9 girls with autism and severe behavioral disturbance and a mental age ≥18 months completed the cognitive part of the study. No decline in performance occurred with risperidone. Performance on a cancellation task (number of correct detections) and a verbal learning task (word recognition) was better on risperidone than on placebo (without correction for multiplicity). Equivocal improvement also occurred on a spatial memory task. There were no significant differences between treatment conditions on the Purdue Pegboard (hand-eye coordination) task or the Analog Classroom Task (timed math test). Conclusion: Risperidone given to children with autism at doses up to 3.5 mg for up to 8 weeks appears to have no detrimental effect on cognitive performance

    Risperidone Treatment of Autistic Disorder: Longer-Term Benefits and Blinded Discontinuation After 6 Months

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    Objective: Risperidone is effective for short-term treatment of aggression, temper outbursts, and self-injurious behavior in children with autism. Because these behaviors may be chronic, there is a need to establish the efficacy and safety of longer-term treatment with this agent. Method: The authors conducted a multisite, two-part study of risperidone in children ages 5 to 17 years with autism accompanied by severe tantrums, aggression, and/or self-injurious behavior who showed a positive response in an earlier 8-week trial. Part I consisted of 4-month open-label treatment with risperidone, starting at the established optimal dose; part II was an 8-week randomized, double-blind, placebo-substitution study of risperidone withdrawal. Primary outcome measures were the Aberrant Behavior Checklist irritability subscale and the Clinical Global Impression improvement scale. Results: Part I included 63 children. The mean risperidone dose was 1.96 mg/day at entry and remained stable over 16 weeks of open treatment. The change on the Aberrant Behavior Checklist irritability subscale was small and clinically insignificant. Reasons for discontinuation of part I included loss of efficacy (N=5) and adverse effects (N=1). The subjects gained an average of 5.1 kg. Part II included 32 patients. The relapse rates were 62.5% for gradual placebo substitution and 12.5% for continued risperidone; this difference was statistically significant. Conclusions: Risperidone showed persistent efficacy and good tolerability for intermediate-length treatment of children with autism characterized by tantrums, aggression, and/or self-injurious behavior. Discontinuation after 6 months was associated with a rapid return of disruptive and aggressive behavior in most subjects
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