1,015 research outputs found

    A LEKID-based CMB instrument design for large-scale observations in Greenland

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    We present the results of a feasibility study, which examined deployment of a ground-based millimeter-wave polarimeter, tailored for observing the cosmic microwave background (CMB), to Isi Station in Greenland. The instrument for this study is based on lumped-element kinetic inductance detectors (LEKIDs) and an F/2.4 catoptric, crossed-Dragone telescope with a 500 mm aperture. The telescope is mounted inside the receiver and cooled to <4<\,4 K by a closed-cycle 4^4He refrigerator to reduce background loading on the detectors. Linearly polarized signals from the sky are modulated with a metal-mesh half-wave plate that is rotated at the aperture stop of the telescope with a hollow-shaft motor based on a superconducting magnetic bearing. The modular detector array design includes at least 2300 LEKIDs, and it can be configured for spectral bands centered on 150~GHz or greater. Our study considered configurations for observing in spectral bands centered on 150, 210 and 267~GHz. The entire polarimeter is mounted on a commercial precision rotary air bearing, which allows fast azimuth scan speeds with negligible vibration and mechanical wear over time. A slip ring provides power to the instrument, enabling circular scans (360 degrees of continuous rotation). This mount, when combined with sky rotation and the latitude of the observation site, produces a hypotrochoid scan pattern, which yields excellent cross-linking and enables 34\% of the sky to be observed using a range of constant elevation scans. This scan pattern and sky coverage combined with the beam size (15~arcmin at 150~GHz) makes the instrument sensitive to 5<<10005 < \ell < 1000 in the angular power spectra

    The prevalence and incidence of mental ill-health in adults with autism and intellectual disabilities

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    The prevalence, and incidence, of mental ill-health in adults with intellectual disabilities and autism were compared with the whole population with intellectual disabilities, and with controls, matched individually for age, gender, ability-level, and Down syndrome. Although the adults with autism had a higher point prevalence of problem behaviours compared with the whole adult population with intellectual disabilities, compared with individually matched controls there was no difference in prevalence, or incidence of either problem behaviours or other mental ill-health. Adults with autism who had problem behaviours were less likely to recover over a two-year period than were their matched controls. Apparent differences in rates of mental ill-health are accounted for by factors other than autism, including Down syndrome and ability level

    Thyrotropin-releasing hormone (TRH) promotes wound re-epithelialisation in frog and human skin

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    There remains a critical need for new therapeutics that promote wound healing in patients suffering from chronic skin wounds. This is, in part, due to a shortage of simple, physiologically and clinically relevant test systems for investigating candidate agents. The skin of amphibians possesses a remarkable regenerative capacity, which remains insufficiently explored for clinical purposes. Combining comparative biology with a translational medicine approach, we report the development and application of a simple ex vivo frog (Xenopus tropicalis) skin organ culture system that permits exploration of the effects of amphibian skin-derived agents on re-epithelialisation in both frog and human skin. Using this amphibian model, we identify thyrotropin-releasing hormone (TRH) as a novel stimulant of epidermal regeneration. Moving to a complementary human ex vivo wounded skin assay, we demonstrate that the effects of TRH are conserved across the amphibian-mammalian divide: TRH stimulates wound closure and formation of neo-epidermis in organ-cultured human skin, accompanied by increased keratinocyte proliferation and wound healing-associated differentiation (cytokeratin 6 expression). Thus, TRH represents a novel, clinically relevant neuroendocrine wound repair promoter that deserves further exploration. These complementary frog and human skin ex vivo assays encourage a comparative biology approach in future wound healing research so as to facilitate the rapid identification and preclinical testing of novel, evolutionarily conserved, and clinically relevant wound healing promoters

    Brucella bacteremia in patients with acute leukemia: a case series

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    <p>Abstract</p> <p>Background</p> <p>Brucellosis may cause serious infections in healthy individuals living in countries that are endemic for the infection. However, reports of brucella infections in immunocompromised hosts are relatively rare.</p> <p>Case Presentations</p> <p>Reported here are two patients with acute leukemia who developed <it>Brucella melitensis </it>bacteremia during their follow up at the Armed Forces Hospital in Riyadh. The first patient developed <it>B. melitensis </it>bacteremia during the transformation of his myelodysplasia into acute myeloid leukemia. The second patient developed <it>B. melitensis </it>bacteremia while his acute lymphoblastic leukemia was under control. Interestingly, he presented with acute cholecystitis during the brucella sepsis. Both brucella infections were associated with a marked reduction in the hematological parameters in addition to other complications. The bacteremic episodes were successfully treated with netilmicin, doxycycline and ciprofloxacin.</p> <p>Conclusion</p> <p>Brucellosis can cause systemic infections, complicated bacteremia and serious morbidity in patients with acute leukemia living in endemic areas. These infections may occur at the presentation of the leukemia or even when the leukemia is in remission. Nevertheless, the early diagnosis of brucellosis and the administration of appropriate antimicrobial therapy for sufficient duration usually improves the outcome in these immunocompromised patients.</p

    Instances and connectors : issues for a second generation process language

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    This work is supported by UK EPSRC grants GR/L34433 and GR/L32699Over the past decade a variety of process languages have been defined, used and evaluated. It is now possible to consider second generation languages based on this experience. Rather than develop a second generation wish list this position paper explores two issues: instances and connectors. Instances relate to the relationship between a process model as a description and the, possibly multiple, enacting instances which are created from it. Connectors refers to the issue of concurrency control and achieving a higher level of abstraction in how parts of a model interact. We believe that these issues are key to developing systems which can effectively support business processes, and that they have not received sufficient attention within the process modelling community. Through exploring these issues we also illustrate our approach to designing a second generation process language.Postprin
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