2,866 research outputs found

    Note on Comparability of MicroCog Test Forms

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    This study investigated the differences between the Standard and Short forms of MicroCog by comparing Domain scores for a clinical sample of 351 substance abusers which gave a significant difference between scores on the Spatial Processing Domain. Implications for research and clinical use are discussed

    Bibliography of South Dakota Climate and Annotations

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    This bibliography is designed to aid scientists, agriculturalists, and others find what research work has been accomplished in Climatology in South Dakota and what data are available for further study and analysis. The list of publications by the Weather Bureau, the tables under Card Library of Weather Data on punch cards, and the Climatological Summaries of Weather Bureau Substations in South Dakota are sources of climatological data for the state. The various other publications listed are results of research work that pertains, at least in part, to Climatology in South Dakota. Although considerable effort was made to list all material available on this subject, some publications may have been inadvertently omitted

    Technology requirements for post-1985 communications satellites

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    The technical and functional requirements for commercial communication satellites are discussed. The need for providing quality service at an acceptable cost is emphasized. Specialized services are postulated in a needs model which forecasts future demands. This needs model is based upon 322 separately identified needs for long distance communication. It is shown that the 1985 demand for satellite communication service for a domestic region such as the United States, and surrounding sea and air lanes, may require on the order of 100,000 MHz of bandwith. This level of demand can be met by means of the presently allocated bandwidths and developing some key technologies. Suggested improvements include: (1) improving antennas so that high speed switching will be possible; (2) development of solid state transponders for 12 GHz and possibly higher frequencies; (3) development of switched or steered beam antennas with 10 db or higher gain for aircraft; and (4) continued development of improved video channel compression techniques and hardware

    Technology requirements for communication satellites in the 1980's

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    The key technology requirements are defined for meeting the forecasted demands for communication satellite services in the 1985 to 1995 time frame. Evaluation is made of needs for services and technical and functional requirements for providing services. The future growth capabilities of the terrestrial telephone network, cable television, and satellite networks are forecasted. The impact of spacecraft technology and booster performance and costs upon communication satellite costs are analyzed. Systems analysis techniques are used to determine functional requirements and the sensitivities of technology improvements for reducing the costs of meeting requirements. Recommended development plans and funding levels are presented, as well as the possible cost saving for communications satellites in the post 1985 era

    Changes in skeletal collagen crosslinks and matrix hydration in high and low turnover chronic kidney disease

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    Chronic kidney disease (CKD) increases fracture risk. The results of this work point to changes in bone collagen and bone hydration as playing a role in bone fragility associated with CKD. INTRODUCTION: Clinical data have documented a clear increase in fracture risk associated with chronic kidney disease (CKD). Preclinical studies have shown reductions in bone mechanical properties although the tissue-level mechanisms for these differences remain unclear. The goal of this study was to assess collagen cross-links and matrix hydration, two variables known to affect mechanical properties, in animals with either high- or low-turnover CKD. METHODS: At 35 weeks of age (>75 % reduction in kidney function), the femoral diaphysis of male Cy/+ rats with high or low bone turnover rates, along with normal littermate (NL) controls, were assessed for collagen cross-links (pyridinoline (Pyd), deoxypyridinoline (Dpd), and pentosidine (PE)) using a high-performance liquid chromatography (HPLC) assay as well as pore and bound water per volume (pw and bw) using a 1H nuclear magnetic resonance (NMR) technique. Material-level biomechanical properties were calculated based on previously published whole bone mechanical tests. RESULTS: Cortical bone from animals with high-turnover disease had lower Pyd and Dpd cross-link levels (-21 % each), lower bw (-10 %), higher PE (+71 %), and higher pw (+46 %) compared to NL. Animals with low turnover had higher Dpd, PE (+71 %), and bw (+7 %) along with lower pw (-60 %) compared to NL. Both high- and low-turnover animals had reduced material-level bone toughness compared to NL animals as determined by three-point bending. CONCLUSIONS: These data document an increase in skeletal PE with advanced CKD that is independent of bone turnover rate and inversely related to decline in kidney function. Although hydration changes occur in both high- and low-turnover disease, the data suggest that nonenzymatic collagen cross-links may be a key factor in compromised mechanical properties of CKD.This work was supported by National Institutes of Health grants AR58005 (SM), DL100093 (CN), AR063157 (JSN), and the Indiana Clinical Translational Science Institute grant TR000162 (CN). The cross-link analysis is the result of work supported with resources and the use of facilities at the VA Tennessee Valley Healthcare System. All authors were involved in the design, conduct and analyses of the study. The authors would like to thank Drew Brown, Shannon Roy, and Kali O’Neill for technical assistance. We would also like to acknowledge the late Dr. Vincent H. Gattone II (1951-2013), who was instrumental in developing this animal model

    Regulation of cilia abundance in multiciliated cells

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    Multiciliated cells (MCC) contain hundreds of motile cilia used to propel fluid over their surface. To template these cilia, each MCC produces between 100-600 centrioles by a process termed centriole amplification. Yet, how MCC regulate the precise number of centrioles and cilia remains unknown. Airway progenitor cells contain two parental centrioles (PC) and form structures called deuterosomes that nucleate centrioles during amplification. Using an ex vivo airway culture model, we show that ablation of PC does not perturb deuterosome formation and centriole amplification. In contrast, loss of PC caused an increase in deuterosome and centriole abundance, highlighting the presence of a compensatory mechanism. Quantification of centriole abundance in vitro and in vivo identified a linear relationship between surface area and centriole number. By manipulating cell size, we discovered that centriole number scales with surface area. Our results demonstrate that a cell-intrinsic surface area-dependent mechanism controls centriole and cilia abundance in multiciliated cells

    A New Class of Majoron-Emitting Double-Beta Decays

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    Motivated by the excess events that have recently been found near the endpoints of the double beta decay spectra of several elements, we re-examine models in which double beta decay can proceed through the neutrinoless emission of massless Nambu-Goldstone bosons (majorons). Noting that models proposed to date for this process must fine-tune either a scalar mass or a VEV to be less than 10 keV, we introduce a new kind of majoron which avoids this difficulty by carrying lepton number L=−2L=-2. We analyze in detail the requirements that models of both the conventional and our new type must satisfy if they are to account for the observed excess events. We find: (1) the electron sum-energy spectrum can be used to distinguish the two classes of models from one another; (2) the decay rate for the new models depends on different nuclear matrix elements than for ordinary majorons; and (3) all models require a (pseudo) Dirac neutrino, having a mass of a several hundred MeV, which mixes with νe\nu_e.Comment: 43 pages, 10 figures (included), [figure captions are now included

    Noise Effects on the Complex Patterns of Abnormal Heartbeats

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    Patients at high risk for sudden death often exhibit complex heart rhythms in which abnormal heartbeats are interspersed with normal heartbeats. We analyze such a complex rhythm in a single patient over a 12-hour period and show that the rhythm can be described by a theoretical model consisting of two interacting oscillators with stochastic elements. By varying the magnitude of the noise, we show that for an intermediate level of noise, the model gives best agreement with key statistical features of the dynamics.Comment: 4 pages, 4 figures, RevTe

    The effect of a diet containing 70% protein from plants on mineral metabolism and musculoskeletal health in chronic kidney disease

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    BACKGROUND: Chronic Kidney Disease (CKD) is associated with alterations in phosphorus excretion, and increases in fibroblast growth factor (FGF23) and parathyroid hormone (PTH). Plant protein-based phytate-bound phosphorus, is less bioavailable than that from animal sources. Our one-week study that was conducted previously showed that a nearly 100% plant protein-based diet benefits mineral metabolism in CKD; however, this diet may not be acceptable to patients. Here we hypothesize that a diet containing 70% protein from plants has similar efficacy and is tolerated by CKD patients. METHODS: Thirteen subjects with CKD 3-4 received an omnivorous diet containing 70% protein from plants for 4 weeks. The primary outcome was change in 24 h urine phosphorus. Secondary outcomes were changes in serum phosphorus, FGF23, PTH, urine sodium excretion, grip strength and fat free mass. Repeated measures analysis of variance (ANOVA) was used to test differences in parameters over the 4 weeks. RESULTS: Mean age of subjects was 54.8 years. Median eGFR was 26 (IQR 14.7) ml/min/1.73 m(2). Over the 4-week period, urine phosphorus significantly decreased by 215 ± 232 mg/day (p < 0.001). No significant changes in serum FGF23, phosphorus or PTH were noted. Urine sodium and titratable acid decreased significantly on the diet. Hand grip strength and fat-free mass did not change. There were two hyperkalemia events both 5.8 mEq/l, corrected by food substitutions. No other adverse events were observed. CONCLUSIONS: A 70% plant protein diet is safe, tolerated, and efficacious in lowering urine phosphorus excretion and may be an alternative to phosphate binders

    Compromised vertebral structural and mechanical properties associated with progressive kidney disease and the effects of traditional pharmacological interventions

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    BACKGROUND/AIMS: Patients with chronic kidney disease mineral and bone disorder (CKD-MBD) have a significantly higher vertebral and non-vertebral fracture risk than the general population. Several preclinical models have documented altered skeletal properties in long bones, but few data exist for vertebral bone. The goal of this study was to examine the effects of progressive CKD on vertebral bone structure and mechanics and to determine the effects of treatment with either bisphosphonates or anti-sclerostin antibody in groups of animals with high or low PTH. METHODS: Animals with progressive kidney disease were left untreated, treated with calcium to lower PTH, zoledronic acid to lower remodeling without affecting PTH, anti-sclerostin antibody, or anti-sclerostin antibody plus calcium. Non-diseased, untreated littermates served as controls. Vertebral bone morphology (trabecular and cortical) and mechanical properties (structural and material-level) were assessed at 35 weeks of age by microCT and mechanical testing, respectively. RESULTS: CKD with high PTH resulted in 6-fold higher bone formation rate, significant reductions in the amount of trabecular and cortical bone, and compromised whole bone mechanical properties in the vertebra compared to normal animals. Treatments that reduced bone remodeling were effective in normalizing vertebral structure and mechanical properties only if the treatment reduced serum PTH. Similarly, treatment with anti-sclerostin antibody was effective in enhancing bone mass and mechanical properties but only if combined with PTH-suppressive treatment. CONCLUSIONS: CKD significantly altered both cortical and trabecular bone properties in the vertebra resulting in compromised mechanical properties and these changes can be normalized by interventions that involve reductions in PTH levels
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