409 research outputs found

    Determination of Point and Nonpoint Source Toxicity in the Clark Fork River Basin Using the Daphnid, Ceriodaphnia Dubia

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    Ceriodaphnia dubia, a small planktonic daphnid was used to biomonitor point sources of toxicity in wastewater and nonpoint source toxicity in stream samples obtained from the Clark Fork River Basin, MT. Brief descriptions, results and discussions are presented for studies of wastewater from a kraft mill near Frenchtown, MT and potential toxicity of water samples from 19 sites along the Clark Fork River in 1985. In 1987, dilutions of Missoula, MT municipal wastewater fortified with ammonia were tested, as was the wastewater before and after chlorination. Potential toxicity of water samples from eight sites along the upper Clark Fork River were also tested. All studies were cooperative efforts with the Montana Departments of Health and Environmental Sciences and Fish, Wildlife and Parks. Ceriodaphnia appear to be indicators of toxicity in a variety of test conditions such as ammonia in wastewater and metals from past mining activities. The daphnids indicated toxicity from other substances in the wastewater or perhaps the influence of characteristics of the wastewater that increased ammonia toxicity. All example of nonpoint source effects was toxicity in samples from Silver Bow Creek MT, where impaired conditions to aquatic life resulting from the presence of metals have been reported for years. During some of the tests with wastewater, toxicological endpoints were observed using the actual number of daphnids that reproduced in a test, not the average number of young. There was circumstantial evidence in 1985 that copper alone was responsible for the toxicity in Silver Bow Creek. However, the later studies performed under different hydrological conditions found toxicity was probably due to a combination of metals, some of which had not been measurable earlier. For well-defined control of standard conditions during testing, there are indications that waters to be used as reference media for Ceriodaphnia need further research. Nevertheless, the use of daphnids to test the ambient conditions described in this paper should encourage environmental managers to consider approaches with this or similar species in the future

    The Fatigue Associated with Depression Questionnaire (FAsD): responsiveness and responder definition

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    PURPOSE: The Fatigue Associated with Depression Questionnaire (FAsD) was developed to assess fatigue and its impact among patients with depression. The purpose of this study was to examine the questionnaire’s responsiveness to change and identify a responder definition for interpretation of treatment-related changes. METHODS: Data were collected at baseline and at 6 weeks from patients with depression starting treatment with a new antidepressant. RESULTS: Of the 96 participants, 55.2% were women, with a mean age of 43.4 years. The total score and both subscales demonstrated statistically significant change with moderate to large effect sizes (absolute values ≥0.76). FAsD change scores were significantly correlated with change on the Brief Fatigue Inventory (r ≥ 0.73; p < 0.001). FAsD mean change scores discriminated among patient subgroups differing by degree of improvement in patient- and clinician-reported fatigue and depression. Responder definition for the two subscales and total score (0.67, 0.57, 0.62) was estimated primarily based on mean change among patients who reported a small but important improvement in fatigue. DISCUSSION: The FAsD was responsive to change, and the responder definition may be used when interpreting treatment-related change. Results add to previous findings suggesting the FAsD is a useful measure of fatigue among patients with depression

    Corticosterone predicts foraging behavior and parental care in Macaroni Penguins

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    Corticosterone has received considerable attention as the principal hormonal mediator of allostasis or physiological stress in wild animals. More recently, it has also been implicated in the regulation of parental care in breeding birds, particularly with respect to individual variation in foraging behaviour and provisioning effort. There is also evidence that prolactin can work either inversely or additively with corticosterone to achieve this. Here we test the hypothesis that endogenous corticosterone plays a key physiological role in the control of foraging behaviour and parental care using a combination of exogenous corticosterone treatment, time-depth telemetry, and physiological sampling of female macaroni penguins (Eudyptes chrysolophus) during the brood-guard period of chick rearing, while simultaneously monitoring patterns of prolactin secretion. Plasma corticosterone levels were significantly higher in females given exogenous implants relative to those receiving sham implants. Increased corticosterone levels were associated with significantly higher levels of foraging and diving activity, and greater mass gain in implanted females. Elevated plasma corticosterone was also associated with an apparent fitness benefit in the form of increased chick mass. Plasma prolactin levels did not correlate with corticosterone levels at any time, nor was prolactin correlated with any measure of foraging behaviour or parental care. Our results provide support for the corticosterone-adaptation hypothesis, which predicts that higher corticosterone levels support increased foraging activity and parental effort

    Serendipitous discoveries in microarray analysis

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    Background Scientists are capable of performing very large scale gene expression experiments with current microarray technologies. In order to find significance in the expression data, it is common to use clustering algorithms to group genes with similar expression patterns. Clusters will often contain related genes, such as co-regulated genes or genes in the same biological pathway. It is too expensive and time consuming to test all of the relationships found in large scale microarray experiments. There are many bioinformatics tools that can be used to infer the significance of microarray experiments and cluster analysis. Materials and methods In this project we review several existing tools and used a combination of them to narrow down the number of significant clusters from a microarray experiment. Microarray data was obtained through the Cerebellar Gene Regulation in Time and Space (Cb GRiTS) database [2]. The data was clustered using paraclique, a graph-based clustering algorithm. Each cluster was evaluated using Gene-Set Cohesion Analysis Tool (GCAT) [3], ONTO-Pathway Analysis [4], and Allen Brain Atlas data [1]. The clusters with the lowest p-values in each of the three analysis methods were researched to determine good candidate clusters for further experimental confirmation of gene relationships. Results and conclusion While looking for genes important to cerebellar development, we serendipitously came across interesting clusters related to neural diseases. For example, we found two clusters that contain genes known to be associated with Parkinson’s disease, Huntington’s disease, and Alzheimer’s disease pathways. Both clusters scored low in all three analyses and have very similar expression patterns but at different expression levels. Such unexpected discoveries help unlock the real power of high throughput data analysis

    Buffered 1% Lidocaine With Epinephrine Can Be as Effective as Nonbuffered 2% Lidocaine With Epinephrine for Maxillary Field Block

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    Buffering local anesthetics with epinephrine (Epi) offers clinicians options not often considered. This study assessed outcomes for pulpal anesthesia, pain on injection, and time to midface numbness for buffered 1% lidocaine with 1:100,000 Epi versus nonbuffered 2% lidocaine with 1:100,000 Epi. In this trial with a randomized, crossover design, buffered 1% lidocaine was compared with nonbuffered 2% lidocaine. Subjects were adult volunteers who served as their own controls. The predictor variables were alternate drug formulations. The outcome variables were subjects' responses to cold and electric pulp testing (EPT) stimulation of the maxillary first molar and canine, pain levels during the injection, and time to midface numbness. After maxillary field blocks with 40 mg of buffered lidocaine or 80 mg of nonbuffered lidocaine, subjects reported pain on injection and responses of the maxillary first molar and canine after cold and EPT stimulation. Teeth were tested before field block and at 30-minute intervals until a positive response was detected. Two weeks later, subjects were tested with the alternate drug combinations. For all outcome variables, assessment of treatment difference, calculated as 1% buffered minus 2% nonbuffered, was performed with the Wilcoxon rank sum test with significance at P < .05. More of the 24 subjects were women and Caucasian. The median age was 23.5 years (interquartile range, 21, 25 years), and the median body weight was 155 lb (interquartile range, 128.5, 176.5 lb). Pain levels during the injection were significantly lower for 1% buffered lidocaine, with P = .04. Times to response after injection were not significantly different between the 2 drug formulations for the cold test on a molar, with P = .08, or the cold test on a canine, with P = .22. However, times to response were significantly longer for nonbuffered drugs for EPT on the molar and canine, both with P = .01. Buffering 1% lidocaine with 1:100,000 Epi reduces the pain on injection with a maxillary field block and results in similar lengths of pulpal anesthesia tested with a cold stimulus as compared with nonbuffered 2% lidocaine with 1:100,000 Epi

    CO J = 3→2 and submillimetre continuum observations of two molecular outflow sources

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    We present CO J=3→2 molecular line spectra, and submillimetre photometry at wavelengths λλ377 μm, 811 μm, and 1136 μm for the sources L1551 and IRC+10216. Detailed analysis of the L1551 spectra indicates the presence of strong velocity gradients in the CO emission zones, implying low optical depths and relatively high densities. The central source IRS 5 displays an infrared excess wihich cannot be explained in terms of a single temperature continuum. The emission zone is probably compact with respect to the instrumental beam size at the wavelength of peak emission (λ~50 μm), and may represent an accretion disc responsible for collimation of the high velocity gas. The far-infrared continuum of IRC+10216 has been synthesised by assuming a distribution of optically thin grains whose emissivity varies as εα λ-1, and the CO J=3→2 spectrum for this source supports earlier J=2→1 observations, implying a variable mass-loss rat
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