7,343 research outputs found

    Efficient Finite Groups Arising in the Study of Relative Asphericity

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    We study a class of two-generator two-relator groups, denoted Jn(m, k), that arise in the study of relative asphericity as groups satisfying a transitional curvature condition. Particular instances of these groups occur in the literature as finite groups of intriguing orders. Here we find infinite families of non-elementary virtually free groups and of finite metabelian non-nilpotent groups, for which we determine the orders. All Mersenne primes arise as factors of the orders of the non-metacyclic groups in the class, as do all primes from other conjecturally infinite families of primes. We classify the finite groups up to isomorphism and show that our class overlaps and extends a class of groups Fa,b,c with trivalent Cayley graphs that was introduced by C.M.Campbell, H.S.M.Coxeter, and E.F.Robertson. The theory of cyclically presented groups informs our methods and we extend part of this theory (namely, on connections with polynomial resultants) to ?bicyclically presented groups? that arise naturally in our analysis. As a corollary to our main results we obtain new infinite families of finite metacyclic generalized Fibonacci groups

    Appearance and management of COVID-19 laryngo-tracheitis: two case reports.

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    We present two cases of coronavirus disease 2019 (COVID-19)-related laryngotracheitis in good-prognosis, ventilated patients who had failed extubation. As the pandemic continues to unfold across the globe and better management of those with respiratory failure develops, this may be an increasingly common scenario. Close ENT-intensivist liaison, meticulous team preparation, early consideration of rigid endoscopy and prospective data collection and case sharing are recommended

    Increased rate of D1 repair in coral symbionts during bleaching is insufficient to counter accelerated photo-inactivation

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    We dissect the primary photo-inactivation and the counteracting metabolic repair rates in fragments of the scleractinian coral, Pocillopora damicornis, subjected to a combined stress of a shift to elevated temperature (from 26°C to 32°C) and increased light (from 200 μmol photons m-2 s-1 to 400 μmol photons m-2 s-1) to induce bleaching. During the bleaching treatment the dinoflagellate symbionts showed a 5.5-fold acceleration in their photosystem II (PSII) repair rate constant, demonstrating that they maintain strong metabolic capacity to clear and replace photo-damaged D1 protein at the elevated temperature and light conditions. Nevertheless, the symbionts concurrently suffered a seven-fold increase in the rate constant for PSII photo-inactivation. This rapid photo-inactivation exceeded the PSII repair capacity, therefore tipping the symbionts, and by implication the symbiosis, into net photo-inhibition. Increased photo-inactivation in hospite, rather than an inhibition of PSII repair, is the principle trigger for net photo-inhibition under bleaching conditions. © 2011, by the American Society of Limnology and Oceanography, Inc

    Review of the Metropolitan Water Plan: Final Report

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    This report was commissioned by the NSW Cabinet Office to review the Metropolitan Water Plan 2004 (DIPNR, 2004a), and was undertaken by the Institute for Sustainable Futures at the University of Technology, Sydney and ACIL Tasman with technical advice from SMEC Australia. In February 2006, our interim review report (ISF, 2006) showed how the supply-demand balance in 2015 could be met with rain-fed supply and a suite of demand management initiatives, and how Sydneys water needs could be secured against the risk of severe drought by having the capacity to deploy groundwater and desalination

    Circulating endothelial cell-derived extracellular vesicles mediate the acute phase response and sickness behaviour associated with CNS inflammation.

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    Brain injury elicits a systemic acute-phase response (APR), which is responsible for co-ordinating the peripheral immunological response to injury. To date, the mechanisms responsible for signalling the presence of injury or disease to selectively activate responses in distant organs were unclear. Circulating endogenous extracellular vesicles (EVs) are increased after brain injury and have the potential to carry targeted injury signals around the body. Here, we examined the potential of EVs, isolated from rats after focal inflammatory brain lesions using IL-1β, to activate a systemic APR in recipient naïve rats, as well as the behavioural consequences of EV transfer. Focal brain lesions increased EV release, and, following isolation and transfer, the EVs were sequestered by the liver where they initiated an APR. Transfer of blood-borne EVs from brain-injured animals was also enough to suppress exploratory behaviours in recipient naïve animals. EVs derived from brain endothelial cell cultures treated with IL-1β also activated an APR and altered behaviour in recipient animals. These experiments reveal that inflammation-induced circulating EVs derived from endothelial cells are able to initiate the APR to brain injury and are sufficient to generate the associated sickness behaviours, and are the first demonstration that EVs are capable of modifying behavioural responses

    Rapid photoprotection in sea-ice diatoms from the East Antarctic pack ice

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    Photoinhibition and D1 protein re-synthesis were investigated in bottom-dwelling sea-ice microalgal communities from the East Antarctic pack ice during early spring. Bottom-dwelling sea-ice microalgal communities were dominated by diatoms that exhibited rapid photoprotection when exposed to a range of different light levels (10 μmol photons m-2 s -1, 50 μmol photons m-2 s-1, 100 μmol photons m-2 s-1, and 200 μmol photons m-2 s-1). Photosynthetic capacity of photosystem II (PSII) dropped significantly over 3 h under 200 μmol photons m-2 s-1, but largely recovered when placed in a low-light environment (10 μmol photons m-2 s-1) for an additional 3 h. PSII repair rates increased with increasing irradiance, and the D1-protein pool remained steady even under high light (200 μmol photons m-2 s-1). Sea-ice diatoms showed a low intrinsic susceptibility to photoinactivation of PSII across all the light treatments, and a strong and irradiance-dependent induction of nonphotochemical quenching, which did not depend upon chloroplast protein synthesis, was also seen. These highly plastic organisms, once thought to be adapted to shade, are in fact well equipped to withstand rapid and relatively large changes in light at low temperatures with minimal long-term effect on their photosynthetic machinery. © 2010, by the American Society of Limnology and Oceanography, Inc

    Patients' and nurses' views on providing psychological support within cardiac rehabilitation programmes: a qualitative study.

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    OBJECTIVE: To explore patients' and nurses' views on the feasibility and acceptability of providing psychological care within cardiac rehabilitation services. DESIGN: In-depth interviews analysed thematically. PARTICIPANTS: 18 patients and 7 cardiac nurses taking part in a pilot trial (CADENCE) of an enhanced psychological care intervention delivered within cardiac rehabilitation programmes by nurses to patients with symptoms of depression. SETTING: Cardiac services based in the South West of England and the East Midlands, UK. RESULTS: Patients and nurses viewed psychological support as central to good cardiac rehabilitation. Patients' accounts highlighted the significant and immediate adverse effect a cardiac event can have on an individual's mental well-being. They also showed that patients valued nurses attending to both their mental and physical health, and felt this was essential to their overall recovery. Nurses were committed to providing psychological support, believed it benefited patients, and advocated for this support to be delivered within cardiac rehabilitation programmes rather than within a parallel healthcare service. However, nurses were time-constrained and found it challenging to provide psychological care within their existing workloads. CONCLUSIONS: Both patients and nurses highly value psychological support being delivered within cardiac rehabilitation programmes but resource constraints raise barriers to implementation. Consideration, therefore, should be given to alternative forms of delivery which do not rely solely on nurses to enable patients to receive psychological support during cardiac rehabilitation. TRIAL REGISTRATION NUMBER: ISCTRN34701576

    Sustainable Affordable Housing - Submission to Inquiry into First Home Ownership

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    The Institute welcomes this opportunity to submit comments to the Commissions Inquiry evaluating the affordability and availability of housing for first home buyers. The Institute for Sustainable Futures is a self-funded research and consulting institute of the University of Technology, Sydney. The Institutes mission is to support and create change towards sustainable futures by working with government, industry and the community. Social sustainability, sustainable housing and sustainable urban infrastructure for energy, water and transport are all key parts of this mission.1 This submission seeks to evaluate the affordability and availability of housing for first home buyers within the framework of ecologically sustainable development (ESD). It is in two parts. Part I: Submission provides the framework. Part II: Comments on the Commissions Issues Paper provides more details on this framework under the broad headings used in the Commissions Issues Paper
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