Linear Actuator Has Long Stroke and High Resolution

The term precision linear actuator, direct drive ( PLADD ) refers to a robust linear actuator designed to be capable of repeatedly performing, over a lifetime of the order of 5 to 10 years, positioning maneuvers that include, variously, submicron increments or slews of the order of a centimeter. The PLADD is capable of both long stroke (120 mm) and high resolution (repeatable increments of 20 nm). Unlike precise linear actuators of prior design, the PLADD contains no gears, levers, or hydraulic converters. The PLADD, now at the prototype stage of development, is intended for original use as a coarse-positioning actuator in a spaceborne interferometer. The PLADD could also be adapted to terrestrial applications in which there are requirements for long stroke and high resolution: potential applications include medical imaging and fabrication of semiconductor devices. The PLADD (see figure) includes a commercially available ball-screw actuator driven directly by a commercially available three-phase brushless DC motor. The ball-screw actuator comprises a spring-preloaded ball nut on a ball screw that is restrained against rotation as described below. The motor is coupled directly (that is, without an intervening gear train) to a drive link that, in turn, is coupled to the ball nut. By eliminating the gear train, the direct-drive design eliminates the complexity, backlash, and potential for misalignment associated with a gear train. To prevent inadvertent movement, there is a brake that includes flexured levers compressed against the drive link by preload springs. This is a power-off brake: There are also piezoelectric stacks that can be activated to oppose the springs and push the levers away from the drive link. Hence, power must be applied to the piezoelectric stacks to release the drive link from braking. To help ensure long operational life, all of the mechanical drive components are immersed in an oil bath within hermetically sealed bellows. The outer end of the bellows holds the outer end of the ball screw, thereby preventing rotation of the ball screw. Positioning is controlled by an electronic control system that includes digital and analog subsystems that interact with the motor and brake and with two sensor/encoder units: a Hall-effect-sensor rotation encoder and a linear glass-scale encoder. This system implements a proportional + integral + derivative control algorithm that results in variation of voltage commands to each of the three pairs of windings of the brushless DC motor. In one of two alternative control modes, the voltages are applied to the windings in a trapezoidal commutation scheme on the basis of timing signals obtained from the Hall-effect sensors; this scheme yields relatively coarse positioning - 24 steps per motor revolution. The second control mode involves a sinusoidal commutation scheme in which the output of the linear glass-scale encoder is transposed to rotational increments to yield much finer position feedback - more than 400,000 steps per revolution

Efficient Photometric Selection of Quasars from the Sloan Digital Sky Survey: 100,000 z<3 Quasars from Data Release One

We present a catalog of 100,563 unresolved, UV-excess (UVX) quasar candidates to g=21 from 2099 deg^2 of the Sloan Digital Sky Survey (SDSS) Data Release One (DR1) imaging data. Existing spectra of 22,737 sources reveals that 22,191 (97.6%) are quasars; accounting for the magnitude dependence of this efficiency, we estimate that 95,502 (95.0%) of the objects in the catalog are quasars. Such a high efficiency is unprecedented in broad-band surveys of quasars. This ``proof-of-concept'' sample is designed to be maximally efficient, but still has 94.7% completeness to unresolved, g<~19.5, UVX quasars from the DR1 quasar catalog. This efficient and complete selection is the result of our application of a probability density type analysis to training sets that describe the 4-D color distribution of stars and spectroscopically confirmed quasars in the SDSS. Specifically, we use a non-parametric Bayesian classification, based on kernel density estimation, to parameterize the color distribution of astronomical sources -- allowing for fast and robust classification. We further supplement the catalog by providing photometric redshifts and matches to FIRST/VLA, ROSAT, and USNO-B sources. Future work needed to extend the this selection algorithm to larger redshifts, fainter magnitudes, and resolved sources is discussed. Finally, we examine some science applications of the catalog, particularly a tentative quasar number counts distribution covering the largest range in magnitude (14.2<g<21.0) ever made within the framework of a single quasar survey.Comment: 35 pages, 11 figures (3 color), 2 tables, accepted by ApJS; higher resolution paper and ASCII version of catalog available at http://sdss.ncsa.uiuc.edu/qso/nbckde

Barrier Island Morphology and Sediment Characteristics Affect the Recovery of Dune Building Grasses following Storm-Induced Overwash

Barrier islands are complex and dynamic systems that provide critical ecosystem services to coastal populations. Stability of these systems is threatened by rising sea level and the potential for coastal storms to increase in frequency and intensity. Recovery of dune-building grasses following storms is an important process that promotes topographic heterogeneity and long-term stability of barrier islands, yet factors that drive dune recovery are poorly understood. We examined vegetation recovery in overwash zones on two geomorphically distinct (undisturbed vs. frequently overwashed) barrier islands on the Virginia coast, USA. We hypothesized that vegetation recovery in overwash zones would be driven primarily by environmental characteristics, especially elevation and beach width. We sampled species composition and environmental characteristics along a continuum of disturbance from active overwash zones to relict overwash zones and in adjacent undisturbed environments. We compared species assemblages along the disturbance chronosequence and between islands and we analyzed species composition data and environmental measurements with Canonical Correspondence Analysis to link community composition with environmental characteristics. Recovering and geomorphically stable dunes were dominated by Ammophila breviligulata Fernaud (Poaceae) on both islands while active overwash zones were dominated by Spartina patens (Aiton) Muhl. (Poaceae) on the frequently disturbed island and bare sand on the less disturbed island. Species composition was associated with environmental characteristics only on the frequently disturbed island (p = 0.005) where A. breviligulata was associated with higher elevation and greater beach width. Spartina patens, the second most abundant species, was associated with larger sediment grain size and greater sediment size distribution. On the less frequently disturbed island, time since disturbance was the only factor that affected community composition. Thus, factors driving the abundance of dune-building grasses and subsequent recovery of dunes varied between the two geomorphically distinct islands

Falls among middle-aged women in the Women’s Interagency HIV Study

To determine the frequency and risk factors for falls among middle-aged HIV+ and HIV− women in the Women's Interagency HIV Study (WIHS)

Cytoprotection by Amifostine during Autologous Stem Cell Transplantation for Advanced Refractory Hematologic Malignancies

Abstract This study evaluated whether amifostine protects against mucositis and other toxicities in patients with advanced, refractory, or recurrent hematologic malignancies undergoing high-dose chemotherapy and total body irradiation. Thirty-five patients (20 with non-Hodgkin lymphoma, 12 with Hodgkin disease, and 3 with acute myelogenous leukemia) who underwent autologous stem cell transplantation were conditioned with total body irradiation 2 Gy twice daily on days −8 through −6; cyclophosphamide 6 g/m2, etoposide 1.8 g/m2, and carboplatin 1 g/m2 on days −5 through −3; and amifostine 500 mg/m2 on days −8 through −2. Prior institutional experience in patients treated without amifostine was used as a historical comparison (no-amifostine group). Severe mucositis occurred in 14 (40%) of 35 patients in the amifostine group, compared with 33 (94%) of 35 in the no-amifostine group (P < .0001). Total parenteral nutrition was used by 4 (11%) of 35 amifostine-treated patients and 34 (97%) of 35 no-amifostine patients (P < .0001). The median duration of narcotic use decreased from 15.5 days with no amifostine to 11 days with amifostine (P = .002). Granulocyte and platelet engraftment times were similar. Prospective trials with innovative designs and clearly defined stopping rules are warranted to confirm whether amifostine reduces the toxicities of a myelosuppressive conditioning regimen before autologous stem cell transplantation without compromising therapeutic response

The Political Economy of Natural Resource Use: Lessons for Fisheries Reform

This report discusses key lessons drawn from reform experience in the wider natural resource sector that might inform successful reform in fisheries. This report is a compilation of 12 papers prepared by acknowledged international experts in the fields of fisheries and wider natural resource reform which were reviewed at a workshop convened by the Property and Environment Research Center (PERC) in May 2009.The report forms an important initial input into an ongoing enquiry into the political economy of fisheries reform initiated by the World Bank in partnership with the Partnership for African Fisheries (a United Kingdom Department for International Development funded program of the New Partnership for African Development (NEPAD))

Recommendations of Common Data Elements to Advance the Science of Selfâ Management of Chronic Conditions

PurposeCommon data elements (CDEs) are increasingly being used by researchers to promote data sharing across studies. The purposes of this article are to (a) describe the theoretical, conceptual, and definition issues in the development of a set of CDEs for research addressing selfâ management of chronic conditions; (b) propose an initial set of CDEs and their measures to advance the science of selfâ management; and (c) recommend implications for future research and dissemination.Design and MethodsBetween July 2014 and December 2015 the directors of the National Institute of Nursing Research (NINR)â funded P20 and P30 centers of excellence and NINR staff met in a series of telephone calls and a faceâ toâ face NINRâ sponsored meeting to select a set of recommended CDEs to be used in selfâ management research. A list of potential CDEs was developed from examination of common constructs in current selfâ management frameworks, as well as identification of variables frequently used in studies conducted in the centers of excellence.FindingsThe recommended CDEs include measures of three selfâ management processes: activation, selfâ regulation, and selfâ efficacy for managing chronic conditions, and one measure of a selfâ management outcome, global health.ConclusionsThe selfâ management of chronic conditions, which encompasses a considerable number of processes, behaviors, and outcomes across a broad range of chronic conditions, presents several challenges in the identification of a parsimonious set of CDEs. This initial list of recommended CDEs for use in selfâ management research is provisional in that it is expected that over time it will be refined. Comment and recommended revisions are sought from the research and practice communities.Clinical RelevanceThe use of CDEs can facilitate generalizability of research findings across diverse population and interventions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134268/1/jnu12233_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134268/2/jnu12233.pd

Biomarkers as Common Data Elements for Symptom and Selfâ Management Science

PurposeBiomarkers as common data elements (CDEs) are important for the characterization of biobehavioral symptoms given that once a biologic moderator or mediator is identified, biologically based strategies can be investigated for treatment efforts. Just as a symptom inventory reflects a symptom experience, a biomarker is an indicator of the symptom, though not the symptom per se. The purposes of this position paper are to (a) identify a â minimum setâ of biomarkers for consideration as CDEs in symptom and selfâ management science, specifically biochemical biomarkers; (b) evaluate the benefits and limitations of such a limited array of biomarkers with implications for symptom science; (c) propose a strategy for the collection of the endorsed minimum set of biologic samples to be employed as CDEs for symptom science; and (d) conceptualize this minimum set of biomarkers consistent with National Institute of Nursing Research (NINR) symptoms of fatigue, depression, cognition, pain, and sleep disturbance.Design and MethodsFrom May 2016 through January 2017, a working group consisting of a subset of the Directors of the NINR Centers of Excellence funded by P20 or P30 mechanisms and NINR staff met bimonthly via telephone to develop this position paper suggesting the addition of biomarkers as CDEs. The full group of Directors reviewed drafts, provided critiques and suggestions, recommended the minimum set of biomarkers, and approved the completed document. Best practices for selecting, identifying, and using biological CDEs as well as challenges to the use of biological CDEs for symptom and selfâ management science are described. Current platforms for sample outcome sharing are presented. Finally, biological CDEs for symptom and selfâ management science are proposed along with implications for future research and use of CDEs in these areas.FindingsThe recommended minimum set of biomarker CDEs include proâ and antiâ inflammatory cytokines, a hypothalamicâ pituitaryâ adrenal axis marker, cortisol, the neuropeptide brainâ derived neurotrophic factor, and DNA polymorphisms.ConclusionsIt is anticipated that this minimum set of biomarker CDEs will be refined as knowledge regarding biologic mechanisms underlying symptom and selfâ management science further develop. The incorporation of biological CDEs may provide insights into mechanisms of symptoms, effectiveness of proposed interventions, and applicability of chosen theoretical frameworks. Similarly, as for the previously suggested NINR CDEs for behavioral symptoms and selfâ management of chronic conditions, biological CDEs offer the potential for collaborative efforts that will strengthen symptom and selfâ management science.Clinical RelevanceThe use of biomarker CDEs in biobehavioral symptoms research will facilitate the reproducibility and generalizability of research findings and benefit symptom and selfâ management science.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143764/1/jnu12378.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143764/2/jnu12378_am.pd

Inland Pacific Northwest pasture calendar

The Inland Pacific Northwest (PNW) region, historically referred to as the 'Inland Empire', extends from the Cascade Mountains in the west to former Glacial Lake Missoula in the Rockies in the east and from the Canadian border in the north past the Snake River Canyon in the south. The greatest agricultural enterprises are hay (from various forage species), irrigated and non-irrigated grassland pastures, rangelands, and livestock production. It is also home to numerous wildlife species and flyways for migrating birds. The Inland PNW Pasture Calendar is designed to be a comprehensive guide for improved grassland management in support of forage-livestock systems. Applying the principles described will lead to improved regional economic, ecological, and social sustainability. This publication describes the opportunities and challenges of sustainably raising harvested and grazed forages and developing forage-livestock systems in this incredibly diverse environment. Appendix Chapters provide key information on grass / legume / forb species, how pasture species grow and regrow, soil nutrient management and organic matter, grazing philosophies and systems, matching grazing needs for pasture production, and forage-related animal health issues. Learning these key principles and following best management practices described will lead to improved sustainability of forage-livestock systems