148 research outputs found

    Global deformation on the surface of Venus

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    Large-scale mapping of tectonic structures on Venus shows that there is an organized global distribution to deformation. The structures we emphasize are linear compressive mountain belts, extensional rafted zones, and the small-scale but widely distributed wrinkle ridges. Ninety percent of the area of the planet's compressive mountain belts are concentrated in the northern hemisphere whereas the southern hemisphere is dominated by extension and small-scale compression. We propose that this striking concentration of fold belts in the northern hemisphere, along with the globe-encircling equatorial rift system, represents a global organization to deformation on Venus

    Fundamental Differences Between Positive and Negative Tone Imaging

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    Abstract The reasons that imaging is tone-dependent come from two fundamental concepts: the aerial images of complimentary mask patterns for partially coherent projection systems are not complimentary, and the exposure reaction is highly non-linear in the concentration of the soluble species. Complimentary mask patterns are simply patterns of opposite tone. If m p (x) describes a positive mask pattern, then its complimentary mask pattern, m n (x), is given by m n (x) = 1 -m p (x). For incoherent imaging systems, complimentary mask patterns result in complimentary images; however, partially coherent imaging systems do not produce complimentary images. For a first order exposure reaction, the concentration of the photosensitive species is exponentially related to the exposure energy. However, the dependence of the concentration of developer-soluble species on exposure is different for positive and negative resist systems, resulting in different exposure properties. The net result is lithographic behavior which can vary significantly with resist tone

    Charged Beads Enhance Cutaneous Wound Healing in Rhesus Non-Human Primates

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    Enhanced cutaneous wound healing by positively charged cross-linked diethylaminoethyl dextran beads (CLOD) was studied in a standardized incisional wound model in 20 adult and 20 geriatric 111acaca mulatta (rhesus) partitioned equally over five time periods. Physiologic saline served as a control. Soft-tissue linear incisions were prepared between and l cm inferior to the scapulae. There were four incisions per rhesus; each incision was 1.5 cm long with 1 cm of undisturbed tissue between incisions, and both the experimental CLDD and physiologic saline treatments were administered to each rhesus. The incision treatments were either CLDD and soft-tissue closure with 4-0 BioSyn sutures or sterile physiologic saline and closure with 4-0 BioSyn smures. The hypothesis was CLDD would enhance cutaneous wound repair. Verification of the h ypothesis consisted of clinical examinations and histologic and tensiometric evaluations on biopsy specimens at 10 and 15 days, whereas 5-day and 2- and 4-month groups were assessed clinically and biopsy specimens were assessed histolog ically. The clinical course of healing for all groups was unremarkable. At 10 days, incisions in adult rhesus treated with CLDD had a 30-percent greater tensile strength compared with the physiologic saline-treated incisions (p = 0.01), whereas for geriatric rhesus, the CLDD treatment proved to be 15 percent greater in tensile strength compared with the physiologic saline cohort (p = 0.11). By day 15, incisions in adult rhesus were 26 percent stronger than the saline treatment group (/J = 0.07), and the difference was 36 percent (p = 0.02) for the geriatric rhesus. From 5 through 15 days, histologic observations revealed a gradual decrease in quantity and integrity of CLOD, with no remnants ofCLDD at either 2 or 4 months. Macrophages and multinucleated giant cells wer.e localized in the dermis and were associated with the CLDD. These cells decreased commensurately with the decrease of CLDD beads. The data suggest that CLDD can enhance significantly the tensile properties of healing cutaneous wounds in both adult and geriatric rhesus. Moreover, if the wound healing is enhanced in geriatric patients, this finding may be clinically germane to conditions where wound healing is compromised, such as in diabetics and patients on steroids

    Introduction to special section: Balancing, restoration, and palinspastic reconstruction

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    Methods to quantify deformation and reverse the process of strain as a mode to illustrate geologic evolution through time have been previously used for a number of decades. Early efforts on the quantification of bed reconstruction were completed either by manually weighing the sections on delicate balances and obtaining the average height and thickness of strata to be reconstructed by applying a scale factor (Chamberlin, 1910), or by hand-drafting sections with conserved bed length between the folded and faulted sedimentary layers, mainly in a 2D cross section (Bally et al., 1966; Dahlstrom, 1969) or map framework (Dennison and Woodward, 1963). Cross-section techniques initially applied to contractional thrust and fold belts and have proven useful in other structural settings, such as extensional and inverted domains. Development of 3D techniques enabled the analysis of strike-slip and salt tectonics where out-of-plane changes of rock volume could be addressed. Through the years, the widespread application of these techniques to predict fault and horizon geometry at depth has generated newer approaches and more sophisticated algorithms, and it has also demonstrated the potential of structural modeling techniques (e.g., construction of balanced sections, palinspastic reconstruction, kinematic and geomechanical restoration, and forward modeling) in reducing the risk and uncertainty associated with the interpretation of geophysical/geological dat

    Maintaining independence in individuals with dementia at home after a fall:a protocol for the UK pilot cluster randomised controlled trial MAINTAIN

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    Introduction: Individuals with dementia face an increased risk of falls. Falls can cause a decline in the individual’s overall functionality. All types of falls, including those that do not result in injury, can lead to psychosocial consequences, such as diminished confidence and a fear of falling. Projections indicate a rising trend in dementia diagnoses, implying an increase in fall incidents. Yet, there is a lack of evidence to support interventions for people living with dementia who have fallen. Our objective is to test the feasibility of a falls intervention trial for people with dementia. Method and analysis: This is a UK-based two-arm pilot cluster randomised controlled trial. In this study, six collaborating sites, which form the clusters, will be randomly allocated to either the intervention arm or the control arm (receiving treatment as usual) at a 1:1 ratio. During the 6 month recruitment phase, each cluster will enrol 10 dyads, comprising 10 individuals with dementia and their respective carers, leading to a total sample size of 60 dyads. The primary outcomes are the feasibility parameters for a full trial (ie, percentage consented, follow-up rate and cost framework). Secondary outcomes include activities of daily living, quality of life, fall efficacy, mobility, goal attainment, cognitive status, occurrence of falls, carer burden and healthcare service utilisation. Outcome measures will be collected at baseline and 28 weeks, with an additional assessment scheduled at 12 weeks for the healthcare service utilisation questionnaire. An embedded process evaluation, consisting of interviews and observations with participants and healthcare professionals, will explore how the intervention operates and the fidelity of study processes. Ethics and dissemination: The study was approved by the NHS and local authority research governance and research ethics committees (NHS REC reference: 23/WA/0126). The results will be shared at meetings and conferences and will be published in peer-reviewed journals. Trial registration number: ISRCTN16413728

    Effectiveness of Progressive and Resisted and Non-Progressive or Non-Resisted Exercise in Rotator Cuff Related Shoulder Pain: A Systematic Review and Meta-analysis of Randomised Controlled Trials

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    Objective: Synthesize evidence regarding effectiveness of progressive and resisted or non-progressive and non-resisted exercise compared with placebo or no treatment, in rotator cuff related pain. Data sources: English articles, searched in Cochrane CENTRAL, MEDLINE, EMBASE and CINAHL databases up until May 19, 2020. Methods: Randomized controlled trials in people with rotator cuff related pain comparing either progressive and resisted exercise or non-progressive and non-resisted exercise, with placebo or no treatment were included. Data extracted independently by two authors. Risk of bias appraised with the Cochrane Collaboration tool. Results: Seven trials (468 participants) were included, four trials (271 participants) included progressive and resisted exercise and three trials (197 participants) included non-progressive or non-resisted exercise. There was uncertain clinical benefit for composite pain and function (15 point difference, 95% CI 9 to 21, 100-point scale) and pain outcomes at >6weeks to 6months with progressive and resisted exercise compared to placebo or no treatment (comparison 1). For non-progressive or non-resisted exercise there was no significant benefit for composite pain and function (4 point difference, 95% CI –2 to 9, 100-point scale) and pain outcomes at >6weeks to 6months compared to placebo or no treatment (comparison 2). Adverse events were seldom reported and mild. Conclusions: There is uncertain clinical benefit for all outcomes with progressive and resisted exercise and no significant benefit with non-progressive and non-resisted exercise, versus no treatment or placebo at >6weeks to 6months. Findings are low certainty and should be interpreted with cautio

    Policy making and energy infrastructure change: A Nigerian case study of energy governance in the electricity sector

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    This paper focusses on investigating the underlying mechanisms and influences of the policy decision making process and how it affects and impacts the governance of the Nigerian energy industry, and energy infrastructure provisions. In-depth semi-structured interviews were used; all interviewees had been involved, directly or indirectly, in energy infrastructure policy decisions in Nigeria. Five key themes subsequently emerged as salient intra-country induced influences that were affecting the governance and performance of the Nigerian energy sector: (1) competencies – i.e. practical knowledge of energy policy making; (2) expectations – i.e. past, present, and forecasted future expectations from the energy industry; (3) legislation – i.e. institutionalized (and unwritten) rules/procedures; (4) future visions – i.e. future vision of the energy industry/energy market; (5) recruiting experts – i.e. recruiting new energy and public policy makers. In addition, three major inter-country induced influences were also identified: (1) the changing dynamics of international and foreign aid; (2) the United Nations Sustainable Development Goals; and (3) the Paris Agreements on Climate Change. The paper concludes by highlighting the policy implications of these influences, and the consequences for policy makers in the governance of the energy industry in ensuring a secured energy future

    Analysis of Temperature-to-Polarization Leakage in BICEP3 and Keck CMB Data from 2016 to 2018

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    The Bicep/Keck Array experiment is a series of small-aperture refracting telescopes observing degree-scale Cosmic Microwave Background polarization from the South Pole in search of a primordial B-mode signature. As a pair differencing experiment, an important systematic that must be controlled is the differential beam response between the co-located, orthogonally polarized detectors. We use high-fidelity, in-situ measurements of the beam response to estimate the temperature-to-polarization (T → P) leakage in our latest data including observations from 2016 through 2018. This includes three years of Bicep3 observing at 95 GHz, and multifrequency data from Keck Array. Here we present band-averaged far-field beam maps, differential beam mismatch, and residual beam power (after filtering out the leading difference modes via deprojection) for these receivers. We show preliminary results of "beam map simulations," which use these beam maps to observe a simulated temperature (no Q/U) sky to estimate T → P leakage in our real data

    Observing low elevation sky and the CMB Cold Spot with BICEP3 at the South Pole

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    BICEP3 is a 520 mm aperture on-axis refracting telescope at the South Pole, which observes the polarization of the cosmic microwave background (CMB) at 95 GHz to search for the B-mode signal from inflationary gravitational waves. In addition to this main target, we have developed a low-elevation observation strategy to extend coverage of the Southern sky at the South Pole, where BICEP3 can quickly achieve degree-scale E-mode measurements over a large area. An interesting E-mode measurement is probing a potential polarization anomaly around the CMB Cold Spot. During the austral summer seasons of 2018-19 and 2019-20, BICEP3 observed the sky with a flat mirror to redirect the beams to various low elevation ranges. The preliminary data analysis shows degree-scale E-modes measured with high signal-to-noise ratio

    Analysis of Temperature-to-Polarization Leakage in BICEP3 and Keck CMB Data from 2016 to 2018

    Get PDF
    The Bicep/Keck Array experiment is a series of small-aperture refracting telescopes observing degree-scale Cosmic Microwave Background polarization from the South Pole in search of a primordial B-mode signature. As a pair differencing experiment, an important systematic that must be controlled is the differential beam response between the co-located, orthogonally polarized detectors. We use high-fidelity, in-situ measurements of the beam response to estimate the temperature-to-polarization (T → P) leakage in our latest data including observations from 2016 through 2018. This includes three years of Bicep3 observing at 95 GHz, and multifrequency data from Keck Array. Here we present band-averaged far-field beam maps, differential beam mismatch, and residual beam power (after filtering out the leading difference modes via deprojection) for these receivers. We show preliminary results of "beam map simulations," which use these beam maps to observe a simulated temperature (no Q/U) sky to estimate T → P leakage in our real data
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