3,790 research outputs found

    A comprehensive survey of Douglas Lake, Cheboygan County, MI.

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    Without knowledge of the natural state of a lake at a given degree of productivity and a profile of its features, it is at best difficult to define what the goal of lake and watershed conservation/management for a lake at that state of development should be. With the objective of developing a full profile of Douglas Lake, Cheboygan County, Michigan, a comprehensive survey was undertaken. The morphometric parameters investigated were a) the method of basin formation, b) morphometry of the lake basin and littoral zone, c) geology underlying the lake basin and watershed, d) underlying soils of the watershed, e) area of the watershed, and f) watershed land use patterns. Physical parameters measured in Douglas Lake included a) depth, b) temperature and summer thermal stratification, c) depth-dependent light intensity, d) conductivity, e) oxygenation, f) chlorophyll a levels, g) alkalinity/hardness, and h) concentrations of nitrogen, phosphorous, and silica (nutrient richness) by strata. Biotic parameters were surveyed by measuring a) the abundance and diversity of non-benthic phytoplankton, b) abundance and diversity of non-benthic zooplanktoon, c) diversity of littoral zone macroinvertebrates, and d) diversity of littoral zone macrophytes. The goal of the survey was to measure the basic morphometric, physical, and biotic parameters of Douglas Lake, analyze the surveyed measurements for their individual indications of trophic status, and ultimately integrate all measurements and analyses to create a picture of the lake's overall productivity. Leeches are usually found under sticks or stones or in the mud on the bottom of lakes, ponds, and streams unless actively in search of food. Of approximately three hundred leeches collected in the Douglas Lake region during June and July, none were found at a depth greater than two feet. The temperature range of the water was between 18 C and 26 C. Gently moving water in protected coves or at the outlets or inlets of lakes is preferred to still water.http://deepblue.lib.umich.edu/bitstream/2027.42/54731/1/3172.pd

    Dietary Transfer of Heavy Metals in Manatees

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    In recent decades, manatees and dugongs globally have exhibited potentially detrimental levels of a variety of heavy metals in their body tissues. The threatened Florida manatee (Trichechus manatus latirostris), which is a subspecies of the West Indian manatee (Trichechus manatus), has shown corresponding high levels of heavy metals in their blood, skin, liver, and kidneys. As obligate herbivores, these animals rely heavily upon seagrasses as a major component of their diet. Globally, seagrasses at low latitudes have high levels of heavy metals in their tissues. Detrimental levels of heavy metals in Sirenians have not been established until now. This study is assessing the heavy metal concentrations of seagrasses in South Florida as a major dietary contributor to manatees, and investigating possible sources of these metals

    Medication adherence in patients with myotonic dystrophy and facioscapulohumeral muscular dystrophy

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    Myotonic dystrophy (DM) and facioscapulohumeral muscular dystrophy (FSHD) are the two most common adult muscular dystrophies and have progressive and often disabling manifestations. Higher levels of medication adherence lead to better health outcomes, especially important to patients with DM and FSHD because of their multisystem manifestations and complexity of care. However, medication adherence has not previously been studied in a large cohort of DM type 1 (DM1), DM type 2 (DM2), and FSHD patients. The purpose of our study was to survey medication adherence and disease manifestations in patients enrolled in the NIH-supported National DM and FSHD Registry. The study was completed by 110 DM1, 49 DM2, and 193 FSHD patients. Notable comorbidities were hypertension in FSHD (44 %) and DM2 (37 %), gastroesophageal reflux disease in DM1 (24 %) and DM2 (31 %) and arrhythmias (29 %) and thyroid disease (20 %) in DM1. Each group reported high levels of adherence based on regimen complexity, medication costs, health literacy, side effect profile, and their beliefs about treatment. Only dysphagia in DM1 was reported to significantly impact medication adherence. Approximately 35 % of study patients reported polypharmacy (taking 6 or more medications). Of the patients with polypharmacy, the DM1 cohort was significantly younger (mean 55.0 years) compared to DM2 (59.0 years) and FSHD (63.2 years), and had shorter disease duration (mean 26 years) compared to FSHD (26.8 years) and DM2 (34.8 years). Future research is needed to assess techniques to ease pill swallowing in DM1 and to monitor polypharmacy and potential drug interactions in DM and FSHD

    Effects of Three Low-Doses of D-Tagatose on Glycemic Control Over Six Months in Subjects with Mild Type 2 Diabetes Mellitus Under Control with Diet and Exercise

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    The primary objective of this study was to evaluate the safety and the effect of D-tagatose on the glycemic control of subjects with type 2 diabetes as determined by HbA1c levels at the end of 6 months of therapy using the subject\u27s own baseline HbA1c level as a comparator. The determination of the minimal dose required to cause a statistically significant reduction in HbA1c was of particular interest. Eight weeks after screening, the qualifying subjects were randomized to receive one of three doses of D-tagatose: 2.5 g TID, 5.0 g TID or 7.5 g TID. Blood levels of HbA1c, fasting blood glucose concentrations, plasma lipids, changes in body weight, changes in body mass index, and change in insulin levels were checked at each study visit and at the end of the study. Treatment success, as measured by the reduction of HbA1c, was greatest for the 7.5 g D-tagatose dose group, although the difference between the treatments was not statistically significant. For fasting glucose, only the 7.5 g dosage group exhibited reductions from baseline at the 3- and 6-month time points. Mean body weights reduced in a dose-response fashion, with the 5.0 g and the 7.5 g D-tagatose doses providing the greatest reductions. D-tagatose at dosages of 2.5 g, 5.0 g, and 7.5 g TID for six months were well tolerated by this subject population. D-tagatose at 5.0 g TID was the minimal dose required to reduce HbA1c. D-tagatose at 7.5 g TID provided the greatest effect in most measured efficacy parameters

    Non-Emergency Medical Transportation Needs of Middle-Aged and Older Adults: A Rural-Urban Comparison in Delaware, USA.

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    Background: Older adults in rural areas have unique transportation barriers to accessing medical care, which include a lack of mass transit options and considerable distances to health-related services. This study contrasts non-emergency medical transportation (NEMT) service utilization patterns and associated costs for Medicaid middle-aged and older adults in rural versus urban areas. Methods: Data were analyzed from 39,194 NEMT users of LogistiCare-brokered services in Delaware residing in rural (68.3%) and urban (30.9%) areas. Multivariable logistic analyses compared trip characteristics by rurality designation. Results: Rural (37.2%) and urban (41.2%) participants used services more frequently for dialysis than for any other medical concern. Older age and personal accompaniment were more common and wheel chair use was less common for rural trips. The mean cost per trip was greater for rural users (difference of $2910 per trip), which was attributed to the greater distance per trip in rural areas. Conclusions: Among a sample who were eligible for subsidized NEMT and who utilized this service, rural trips tended to be longer and, therefore, higher in cost. Over 50% of trips were made for dialysis highlighting the need to address prevention and, potentially, health service improvements for rural dialysis patients

    Computer Proficiency for Online Learning: Factorial Invariance of Scores among Teachers

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    Online learning is variously employed in K-12 education, including for teacher professional development. However, the use of computer-based technologies for learning purposes assumes learner computer proficiency, making this construct an important domain of procedural knowledge in formal and informal online learning contexts. Addressing this concern, this study examined the score properties and invariance (N=11,709) of an eight-item self-report measure of computer proficiency for online learning, the CPOL. Results from a confirmatory factor analysis suggest that the hypothesized unidimensional structure undergirded the instrumentā€™s scores, and invariance analyses suggested that the instrument functions similarly across teacher populations defined by gender, grade level taught, and age, and over time. Specifically, the results showed strict score invariance for all teacher groupings except for age. Discussed are potential proximal and distal applications of, and directions for future research concerning the CPOL

    Subtle Recognition of 14-Base Pair DNA Sequences via Threading Polyintercalation

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    ABSTRACT: Small molecules that bind DNA in a sequence-specific manner could act as antibiotic, antiviral, or anticancer agents because of their potential ability to manipulate gene expression. Our laboratory has developed threading poly-intercalators based on 1,4,5,8-naphthalene diimide (NDI) units connected in a head-to-tail fashion by flexible peptide linkers. Previously, a threading tetraintercalator composed of alternating minorāˆ’majorāˆ’minor groove-binding modules was shown to bind specifically to a 14 bp DNA sequence with a dissociation half-life of 16 days [Holman, G. G., et al. (2011) Nat. Chem. 3, 875āˆ’881]. Herein are described new NDI-based tetraintercalators with a different major groove-binding module and a reversed N to C directionality of one of the minor groove-binding modules. DNase I footprinting and kinetic analyses revealed that these new tetraintercalators are able to discriminate, by as much as 30-fold, 14 bp DNA binding sites that differ by 1 or 2 bp. Relative affinities were found to correlate strongly with dissociation rates, while overall C2 symmetry in the DNA-binding molecule appeared to contribute to enhanced association rates

    Further Testing of an Amine-based Pressure-Swing System for Carbon Dioxide and Humidity Control

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    In a crewed spacecraft environment, atmospheric carbon dioxide (CO2) and moisture control are crucial. Hamilton Sundstrand has developed a stable and efficient amine-based CO2 and water vapor sorbent, SA9T, that is well suited for use in a spacecraft environment. The sorbent is efficiently packaged in pressure-swing regenerable beds that are thermally linked to improve removal efficiency and minimize vehicle thermal loads. Flows are all controlled with a single spool valve. This technology has been baselined for the new Orion spacecraft. However, more data was needed on the operational characteristics of the package in a simulated spacecraft environment. A unit was therefore tested with simulated metabolic loads in a closed chamber at Johnson Space Center during the last third of 2006. Those test results were reported in a 2007 ICES paper. A second test article was incorporated for a third phase of testing, and that test article was modified to allow pressurized gas purge regeneration on the launch pad in addition to the standard vacuum regeneration in space. Metabolic rates and chamber volumes were also adjusted to reflect current programmatic standards. The third phase of tests was performed during the spring and summer of 2007. Tests were run with a range of operating conditions, varying: cycle time, vacuum pressure (or purge gas flow rate), air flow rate, and crew activity levels. Results of this testing are presented and potential flight operational strategies discussed
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