3,047 research outputs found

    Apollo experience report: Development of guidance targeting techniques for the command module and launch vehicle

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    The development of the guidance targeting techniques for the Apollo command module and launch vehicle is discussed for four types of maneuvers: (1) translunar injection, (2) translunar midcourse, (3) lunar orbit insertion, and (4) return to earth. The development of real-time targeting programs for these maneuvers and the targeting procedures represented are discussed. The material is intended to convey historically the development of the targeting techniques required to meet the defined target objectives and to illustrate the solutions to problems encountered during that development

    Complementary and Alternative Medicine Use in Musculoskeletal Disorders: Does Medical Skepticism Matter?

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    Medical skepticism is the reservation about the ability of conventional medical care to significantly improve health. Individuals with musculoskeletal disorders seeing specialists usually experience higher levels of disability; therefore it is expected they might be more skeptical of current treatment and thus more likely to try Complementary and Alternative Medicine (CAM). The goal of this study was to define these relationships. These data were drawn from a cross-sectional survey from two cohorts: those seeing specialists (n=1,344) and non-specialists (n=724). Site-level fixed effects logistic regression models were used to test associations between medical skepticism and 10 CAM use categories. Some form of CAM was used by 88% of the sample. Increased skepticism was associated with one CAM category for the non-specialist group and six categories for the specialist group. Increased medical skepticism is associated with CAM use, but medical skepticism is more often associated with CAM use for those seeing specialists

    Facilitation of Neuropathic Pain by the NPY Y1 Receptor-Expressing Subpopulation of Excitatory Interneurons in the Dorsal Horn

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    Endogenous neuropeptide Y (NPY) exerts long-lasting spinal inhibitory control of neuropathic pain, but its mechanism of action is complicated by the expression of its receptors at multiple sites in the dorsal horn: NPY Y1 receptors (Y1Rs) on post-synaptic neurons and both Y1Rs and Y2Rs at the central terminals of primary afferents. We found that Y1R-expressing spinal neurons contain multiple markers of excitatory but not inhibitory interneurons in the rat superficial dorsal horn. To test the relevance of this spinal population to the development and/or maintenance of acute and neuropathic pain, we selectively ablated Y1R-expressing interneurons with intrathecal administration of an NPY-conjugated saporin ribosomal neurotoxin that spares the central terminals of primary afferents. NPY-saporin decreased spinal Y1R immunoreactivity but did not change the primary afferent terminal markers isolectin B4 or calcitonin-gene-related peptide immunoreactivity. In the spared nerve injury (SNI) model of neuropathic pain, NPY-saporin decreased mechanical and cold hypersensitivity, but disrupted neither normal mechanical or thermal thresholds, motor coordination, nor locomotor activity. We conclude that Y1R-expressing excitatory dorsal horn interneurons facilitate neuropathic pain hypersensitivity. Furthermore, this neuronal population remains sensitive to intrathecal NPY after nerve injury. This neuroanatomical and behavioral characterization of Y1R-expressing excitatory interneurons provides compelling evidence for the development of spinally-directed Y1R agonists to reduce chronic neuropathic pain

    Use of Complementary and Alternative Medicine Among Patients With Arthritis

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    Introduction: Previous studies suggest that people with arthritis have high rates of using complementary and alternative medicine (CAM) approaches for managing their arthritis, in addition to conventional treatments such as prescription medications. However, little is known about the use of CAM by diagnosis, or which forms of CAM are most frequently used by people with arthritis. This study was designed to provide detailed information about use of CAM for symptoms associated with arthritis in patients followed in primary care and specialty clinics in North Carolina. Methods: Using a cross-sectional design, we drew our sample from primary care (n = 1,077) and specialist (n = 1,063) physician offices. Summary statistics were used to calculate differences within and between diagnostic groups, practice settings, and other characteristics. Logistic regression models clustered at the site level were used to determine the effect of patient characteristics on ever and current use of 9 CAM categories and an overall category of "any use." Results: Most of the participants followed by specialists (90.5%) and a slightly smaller percentage of those in the primary care sample (82.8%) had tried at least 1 complementary therapy for arthritis symptoms. Participants with fibromyalgia used complementary therapies more often than those with rheumatoid arthritis, osteoarthritis, or chronic joint symptoms. More than 50% of patients in both samples used over-the-counter topical pain relievers, more than 25% used meditation or drew on religious or spiritual beliefs, and more than 19% used a chiropractor. Women and participants with higher levels of education were more likely to report current use of alternative therapies. Conclusion: Most arthritis patients in both primary care and specialty settings have used CAM for their arthritis symptoms. Health care providers (especially musculoskeletal specialists) should discuss these therapies with all arthritis patients

    A Multimetric Assessment of Stream Condition in the Northern Lakes and Forests Ecoregion Using Spatially Explicit Statistical Modeling and Regional Normalization

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    We sampled fish communities, water temperature, water chemistry, physical habitat, and catchment characteristics for 94 stream sites selected randomly throughout the Northern Lakes and Forests ecoregion and used those data to explicitly model reference conditions and assess ecological stream condition at each site via a regional normalization framework. The streams we sampled were first order through fourth order, and the catchments ranged from 0.9 to 458 km2. We developed multiple linear regression (MLR) models that predicted fish community metrics, water chemistry characteristics, and local physical habitat from catchment characteristics; we used these models to compare existing conditions with the conditions that would be expected based on the regression models. Our results indicated that the fish communities were relatively unimpaired because the catchment variables associated with human‐induced land use change were important in only 1 of the 10 fish metric models. Agricultural land use was a significant variable in the MLR equation for species of Lepomis (sunfish). Agricultural land use and urban land use were both significant variables in all of the MLR models predicting water chemistry variables; urban land use was a significant variable in the MLR model predicting the percent coverage of all instream cover types. Regional normalization indicated that none of the sites were impaired based on fish community attributes. However, our analysis based on water chemistry metrics indicated that 22– 35% of the sites were impaired and that, based on physical habitat, 6–14% of the sites were impaired. A comparison with other published studies of the ecoregion suggested that the regional normalization process correctly characterized stream condition.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141590/1/tafs0697.pd

    Sensitization of spinal cord nociceptive neurons with a conjugate of substance P and cholera toxin

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    <p>Abstract</p> <p>Background</p> <p>Several investigators have coupled toxins to neuropeptides for the purpose of lesioning specific neurons in the central nervous system. By producing deficits in function these toxin conjugates have yielded valuable information about the role of these cells. In an effort to specifically stimulate cells rather than kill them we have conjugated the neuropeptide substance P to the catalytic subunit of cholera toxin (SP-CTA). This conjugate should be taken up selectively by neurokinin receptor expressing neurons resulting in enhanced adenylate cyclase activity and neuronal firing.</p> <p>Results</p> <p>The conjugate SP-CTA stimulates adenylate cyclase in cultured cells that are transfected with either the NK1 or NK2 receptor, but not the NK3 receptor. We further demonstrate that intrathecal injection of SP-CTA in rats induces the phosphorylation of the transcription factor cyclic AMP response element binding protein (CREB) and also enhances the expression of the immediate early gene c-Fos. Behaviorally, low doses of SP-CTA (1 ÎŒg) injected intrathecally produce thermal hyperalgesia. At higher doses (10 ÎŒg) peripheral sensitivity is suppressed suggesting that descending inhibitory pathways may be activated by the SP-CTA induced sensitization of spinal cord neurons.</p> <p>Conclusion</p> <p>The finding that stimulation of adenylate cyclase in neurokinin receptor expressing neurons in the spinal cord produces thermal hyperalgesia is consistent with the known actions of these neurons. These data demonstrate that cholera toxin can be targeted to specific cell types by coupling the catalytic subunit to a peptide agonist for a g-protein coupled receptor. Furthermore, these results demonstrate that SP-CTA can be used as a tool to study sensitization of central neurons in vivo in the absence of an injury.</p

    Pediatric Phantom Dosimetry Evaluation of the Extraoral Bitewing

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    Purpose: This study’s purpose was to evaluate the effective dose (E) and equivalent dose (HT) of exposing a pediatric phantom to the extraoral bitewing programs of the Planmeca ProMax 2D S3 (ProMax) and Instrumentarium Orthopantomograph OP30 (OP30) and compare these results with dosimetry associated with the intraoral bitewing and panoramic radiograph. Methods: Dosimetry was acquired by placing 24 dosimeters in tissues of interest in a 10-year-old phantom. Manufacturer child settings were used for all scans. Repeat exposures of 20 scans were utilized. The average values of E and HT were calculated. Results: The E for the ProMax and OP30 units, respectively, were 16.84 ÎŒSv and 5.82 ÎŒSv. The highest E for both units was delivered to the thyroid, remainder tissues, and salivary glands. The highest HT for both units was delivered to the oral mucosa, salivary glands, extrathoracic airway, and thyroid. The mean differences between units were statistically significant (P<0.05). Conclusions: The average effective dose of the ProMax was higher than for the OP30. The effective dose of the pediatric extraoral bitewing is three to 11 times higher than that of the intraoral bitewing and comparable to the traditional panoramic radiograph of a pediatric phantom. Pediatric extraoral bitewing radiation protection guidelines are recommended

    Developing User‐Friendly Habitat Suitability Tools from Regional Stream Fish Survey Data

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    We developed user‐friendly fish habitat suitability tools (plots) for fishery managers in Michigan; these tools are based on driving habitat variables and fish population estimates for several hundred stream sites throughout the state. We generated contour plots to show patterns in fish biomass for over 60 common species (and for 120 species grouped at the family level) in relation to axes of catchment area and low‐flow yield (90% exceedance flow divided by catchment area) and also in relation to axes of mean and weekly range of July temperatures. The plots showed distinct patterns in fish habitat suitability at each level of biological organization studied and were useful for quantitatively comparing river sites. We demonstrate how these plots can be used to support stream management, and we provide examples pertaining to resource assessment, trout stocking, angling regulations, chemical reclamation of marginal trout streams, indicator species, instream flow protection, and habitat restoration. These straightforward and effective tools are electronically available so that managers can easily access and incorporate them into decision protocols and presentations.Received April 9, 2010; accepted November 8, 2010Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141005/1/nafm0041.pd
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