178 research outputs found

    Aperture array development for future large radio telescopes

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    We present the design of a phased array system for future radio telescopes. This includes a system overview and recent results of the designed and implemented system, the Electronic Multi-Beam Radio Astronomy Concept (EMBRACE). Furthermore, simulations with a full-EM antenna simulator, combined with measurements on actual hardware, will provide information for the next design step, the Aperture Array Verification System (AAVS). With AAVS, we will prove design readiness of this novel array technology

    DETERMINANTS OF RETURN TO ACTIVE USE AMONGST PREVIOUSLY REHABILITATED USERS OF NYAOPE WITH A HISTORY OF MULTIPLE REHABILITATIONS

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    Returning to active use of nyaope is one of the most problematic issues amongst previously rehabilitated persons who use this substance in South Africa. To understand this aspect in-depth, the study sought to explore the determinants of return to active use from those who have been rehabilitated multiple times. An exploratory qualitative design was utilised for this study. A semi-structured interview guide was developed, and face-to-face interviews were conducted with 13 participants who were recruited from a rehabilitation centre in Tshwane, Gauteng, South Africa. Interpretive phenomenological analysis was the method utilised to analyse the data collected. During analysis, lack of mental determination/compelled rehabilitation, incomplete rehabilitation sessions, failure to cope with stressful life events, supernatural influence, boredom, and hanging out with the same peers who are active users of nyaope, were identified as determinants of relapse. The findings of this study show that successful detoxification and therapy do not guarantee sustainable abstinence from nyaope. The results of this study highlight the need to improve the current interventions by incorporating strategies that will prevent users from returning to active use after going through the rehabilitation process

    When the frame fits the social picture:The effects of framed social norm messages on healthy and unhealthy food consumption

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    We investigated the influence of framed norm messages about food consumption on motivation to consume, and actual consumption of, healthy and unhealthy foods. We proposed that the effects of positive and negative message frames would vary by the type of underlying norms (i.e., injunctive, descriptive). More specifically, based on information processing theories, it was expected that injunctive norms would be more effective when framed negatively compared with positively, while the opposite was expected for descriptive norms. In both experiments, participants were randomly assigned to one of four framed social norm conditions or a no-norm control condition. In experiment 1, motivation to consume healthy and unhealthy foods was assessed by means of both indirect and self-report measures. In experiment 2, actual food consumption was assessed. In both experiments, the predicted interaction was found. Results show that injunctive norms benefit from a negative (vs. Positive) frame, while preliminary evidence suggests the opposite for descriptive norms

    Regional thermal specialisation in a mammal: temperature affects power output of core muscle more than that of peripheral muscle in adult mice (Mus musculus)

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    In endotherms, such as mammals and birds, internal organs can specialise to function within a narrow thermal range. Consequently, these organs should become more sensitive to changes in body temperature. Yet, organs at the periphery of the body still experience considerable fluctuations in temperature, which could select for lower thermal sensitivity. We hypothesised that the performance of soleus muscle taken from the leg would depend less on temperature than would the performance of diaphragm muscle taken from the body core. Soleus and diaphragm muscles were isolated from mice and subjected to isometric and work-loop studies to analyse mechanical performance at temperatures between 15 and 40 °C. Across this thermal range, soleus muscle took longer to generate isometric force and longer to relax, and tended to produce greater normalised maximal force (stress) than did diaphragm muscle. The time required to produce half of maximal force during isometric tetanus and the time required to relax half of maximal force were both more sensitive to temperature in soleus than they were in diaphragm. However, thermal sensitivities of maximal force during isometric tetani were similar for both muscles. Consistent with our hypothesis, power output (the product of speed and force) was greater in magnitude and more thermally sensitive in diaphragm than it was in soleus. Our findings, when combined with previous observations of muscles from regionally endothermic fish, suggest that endothermy influences the thermal sensitivities of power output in core and peripheral muscles

    Prevalence and risk factors of delirium in psychogeriatric outpatients

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    Background: Delirium is a serious neuropsychiatric syndrome, which requires timely treatment. However, it is easily missed, especially in older patients with premorbid cognitive disorders. Objectives: The aim of this study is to investigate the prevalence and risk factors of delirium in older outpatients with and without dementia. Method: We assessed 444 patients referred to the memory clinic of a psychiatric hospital between March 2013 and March 2014. Demographic information, medical history, impairments in daily living activities and referral information were registered. Patients underwent a psychiatric examination using the Delirium Rating Scale-Revised-98 and cognitive tests, a physical examination and laboratory tests. We recorded medication use and changes before and after the onset of symptoms. Results: Among the 444 outpatients, 85 had probable delirium (prevalence of 19%), and 10 had subsyndromal delirium (2%). The most common triggers were infection (42%), drug-intoxication or withdrawal (22%), and metabolic/endocrine disturbance (12%). Age (OR 1.07, 95% CI 1.02-1.11) and prior delirium (OR 3.34, 95% CI 1.28-8.69) were independent non-modifiable factors associated with an increased risk of delirium. The only independent modifiable risk factor was infection (OR 17.31, 95% CI 8.44-35.49). Conclusions: A delirium was detected in one of five patients referred for dementia screening. Most patients could be treated at home. Age and prior delirium were predictive of an increased risk of delirium

    B-cell targeting with anti-CD38 daratumumab:implications for differentiation and memory responses

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    B cell–targeted therapies, such as CD20-targeting mAbs, deplete B cells but do not target the autoantibody-producing plasma cells (PCs). PC-targeting therapies such as daratumumab (anti-CD38) form an attractive approach to treat PC-mediated diseases. CD38 possesses enzymatic and receptor capabilities, which may impact a range of cellular processes including proliferation and differentiation. However, very little is known whether and how CD38 targeting affects B-cell differentiation, in particular for humans beyond cancer settings. Using in-depth in vitro B-cell differentiation assays and signaling pathway analysis, we show that CD38 targeting with daratumumab demonstrated a significant decrease in proliferation, differentiation, and IgG production upon T cell–dependent B-cell stimulation. We found no effect on T-cell activation or proliferation. Furthermore, we demonstrate that daratumumab attenuated the activation of NF-κB in B cells and the transcription of NF-κB–targeted genes. When culturing sorted B-cell subsets with daratumumab, the switched memory B-cell subset was primarily affected. Overall, these in vitro data elucidate novel non-depleting mechanisms by which daratumumab can disturb humoral immune responses. Affecting memory B cells, daratumumab may be used as a therapeutic approach in B cell–mediated diseases other than the currently targeted malignancies.</p

    B-cell targeting with anti-CD38 daratumumab:implications for differentiation and memory responses

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    B cell–targeted therapies, such as CD20-targeting mAbs, deplete B cells but do not target the autoantibody-producing plasma cells (PCs). PC-targeting therapies such as daratumumab (anti-CD38) form an attractive approach to treat PC-mediated diseases. CD38 possesses enzymatic and receptor capabilities, which may impact a range of cellular processes including proliferation and differentiation. However, very little is known whether and how CD38 targeting affects B-cell differentiation, in particular for humans beyond cancer settings. Using in-depth in vitro B-cell differentiation assays and signaling pathway analysis, we show that CD38 targeting with daratumumab demonstrated a significant decrease in proliferation, differentiation, and IgG production upon T cell–dependent B-cell stimulation. We found no effect on T-cell activation or proliferation. Furthermore, we demonstrate that daratumumab attenuated the activation of NF-?B in B cells and the transcription of NF-?B–targeted genes. When culturing sorted B-cell subsets with daratumumab, the switched memory B-cell subset was primarily affected. Overall, these in vitro data elucidate novel non-depleting mechanisms by which daratumumab can disturb humoral immune responses. Affecting memory B cells, daratumumab may be used as a therapeutic approach in B cell–mediated diseases other than the currently targeted malignancies

    Cryoscope:A Cryogenic Infrared Survey Telescope in Antarctica

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    We present Cryoscope--a new 50 deg2 field-of-view, 1.2 m aperture, Kdark survey telescope to be located at Dome C, Antarctica. Cryoscope has an innovative optical-thermal design wherein the entire telescope is cryogenically cooled. Cryoscope also explores new detector technology to cost-effectively tile the full focal plane. Leveraging the dark Antarctic sky and minimizing telescope thermal emission, Cryoscope achieves unprecedented deep, wide, fast and red observations, matching and exceeding volumetric survey speeds from the Ultraviolet Explorer, Vera Rubin Observatory, Nancy Grace Roman Space Telescope, SPHEREx, and NEO Surveyor. By providing coverage beyond wavelengths of 2 μm, we aim to create the most comprehensive dynamic movie of the most obscured reaches of the Universe. Cryoscope will be a dedicated discovery engine for electromagnetic emission from coalescing compact binaries, Earth-like exoplanets orbiting cold stars, and multiple facets of time-domain, stellar and solar system science. In this paper, we describe the scientific drivers and technical innovations for this new discovery engine operating in the Kdark passband, why we choose to deploy it in Antarctica, and the status of a fifth-scale prototype designed as a Pathfinder to retire technological risks prior to full-scale implementation. We plan to deploy the Cryoscope Pathfinder to Dome C in December 2026 and the full-scale telescope by 2030
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