10,829 research outputs found

    Effect of Maple Sugaring on Leaf Litter Decomposition in Vermont Forests

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    The purpose of this study was to examine if tapping sugar maple trees alters the decomposition of their leaf litter. To do this, leaf litter collection baskets were placed in tapped and untapped stands of maple trees in Proctor Maple Research Center in Underhill, Vermont. Litter was allowed to collect in the baskets throughout the fall 2016 season, and then the leaves were dried, weighed, and run through a nutrient analyzer. The nutrient analysis yielded percent nitrogen by weight, percent carbon by weight, and carbon nitrogen ratios for each sample. It was found that the leaf litter of untapped samples had significantly more nitrogen and significantly lower carbon nitrogen ratios than the leaf litter collected in the tapped stand. This indicates a likely change in the decomposition of the leaves in each stand, because nutrient ratios have been shown to alter decomposition rates for leaves. One of the implications of slowed decomposition is retarded nutrient cycling, which could lead to a reduction in available nitrogen, a limiting nutrient for sugar maples, in the forest’s soil. More research should be done to determine the origin of the difference in nutrients. Additionally, a longer-term study is necessary to monitor the decomposition rates in this forest

    Unbiased estimation of multi-fractal dimensions of finite data sets

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    We present a novel method for determining multi-fractal properties from experimental data. It is based on maximising the likelihood that the given finite data set comes from a particular set of parameters in a multi-parameter family of well known multi-fractals. By comparing characteristic correlations obtained from the original data with those that occur in artificially generated multi-fractals with the {\em same} number of data points, we expect that predicted multi-fractal properties are unbiased by the finiteness of the experimental data.Comment: LaTeX, 17 pages, figures encapsulated as picture environment

    Alexithymia and apathy in Parkinson's disease: neurocognitive correlates

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    Non-motor symptoms such as neuropsychiatric and cognitive dysfunction have been found to be common in Parkinson’s disease (PD) but the relation between such symptoms is poorly understood. We focused on alexithymia, an impairment of affective and cognitive emotional processing, as there is evidence for its interaction with cognition in other disorders. Twenty-two non-demented PD patients and 22 matched normal control adults (NC) were administered rating scales assessing neuropsychiatric status, including alexithymia, apathy, and depression, and a series of neuropsychological tests. As expected, PD patients showed more alexithymia than NC, and there was a significant association between alexithymia and disease stage. Alexithymia was associated with performance on non-verbally mediated measures of executive and visuospatial function, but not on verbally mediated tasks. By contrast, there was no correlation between cognition and ratings of either depression or apathy. Our findings demonstrate a distinct association of alexithymia with non-verbal cognition in PD, implicating right hemisphere processes, and differentiate between alexithymia and other neuropsychiatric symptoms in regard to PD cognition.Published versio

    Proton synchrotron radiation of large-scale jets in active galactic nuclei

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    I propose a new mechanism for explanation of nonthernal X-ray emission of large-scale AGN jets. Namely, I assume that this radiation has synchrotron origin emitted by extremely high energy protons, and discuss implications of this model for several prominent hot spots and knots resolved by Chandra in Pictor A, 3C 120, PKS 0637-752, 3C 273.Comment: 17 pages, 8 figures, submitted to MNRA

    Data processing system for the intensity monitoring spectrometer flown on the Orbiting Geophysical Observatory-F (OGO-F) satellite

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    The system is discussed which was developed to process digitized telemetry data from the intensity monitoring spectrometer flown on the Orbiting Geophysical Observatory (OGO-F) Satellite. Functional descriptions and operating instructions are included for each program in the system

    The impact of motor symptoms on self-reported anxiety in Parkinson's disease

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    OBJECTIVE: Anxiety is commonly endorsed in Parkinson's disease (PD) and significantly affects quality of life. The Beck Anxiety Inventory (BAI) is often used but contains items that overlap with common PD motor symptoms (e.g., “hands trembling”). Because of these overlapping items, we hypothesized that PD motor symptoms would significantly affect BAI scores. METHODS: One hundred non-demented individuals with PD and 74 healthy control participants completed the BAI. PD motor symptoms were assessed by the Unified Parkinson's Disease Rating Scale (UPDRS). Factor analysis of the BAI assessed for a PD motor factor, and further analyses assessed how this factor affected BAI scores. RESULTS: BAI scores were significantly higher for PD than NC. A five-item PD motor factor correlated with UPDRS observer-rated motor severity and mediated the PD-control difference on BAI total scores. An interaction occurred, whereby removal of the PD motor factor resulted in a significant reduction in BAI scores for PD relative to NC. The correlation between the BAI and UPDRS significantly declined when controlling for the PD motor factor. CONCLUSIONS: The results indicate that commonly endorsed BAI items may reflect motor symptoms such as tremor instead of, or in addition to, genuine mood symptoms. These findings highlight the importance of considering motor symptoms in the assessment of anxiety in PD and point to the need for selecting anxiety measures that are less subject to contamination by the motor effects of movement disorders.Published versio

    Creating A Social Studies Curriculum For Second Grade

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    The research question discussed in this project was: how can an unbiased social studies curriculum for second grade be developed that is aligned with the MN State Social Studies Standards? It chronicles one educator’s creation of a social studies curriculum unit plan based on citizen and government as its area of focus. It is aligned with the MN State Standards for Social Studies for Second Grade. The author cites the details of the unit and uses research that is pertinent to the creation and development of the unit. This unit includes a scope and sequence, and includes a variety of lessons that encompass differentiation, is free from biases, promotes student engagement, and encourages shared multiple perspectives
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