1,017 research outputs found

    Scaling in ordered and critical random Boolean networks

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    Random Boolean networks, originally invented as models of genetic regulatory networks, are simple models for a broad class of complex systems that show rich dynamical structures. From a biological perspective, the most interesting networks lie at or near a critical point in parameter space that divides ``ordered'' from ``chaotic'' attractor dynamics. In the ordered regime, we show rigorously that the average number of relevant nodes (the ones that determine the attractor dynamics) remains constant with increasing system size N. For critical networks, our analysis and numerical results show that the number of relevant nodes scales like N^{1/3}. Numerical experiments also show that the median number of attractors in critical networks grows faster than linearly with N. The calculations explain why the correct asymptotic scaling is observed only for very large N.Comment: 4 pages, 3 figures; (Re)submitted to Physical Review Letter

    On acceleration of Krylov-subspace-based Newton and Arnoldi iterations for incompressible CFD: replacing time steppers and generation of initial guess

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    We propose two techniques aimed at improving the convergence rate of steady state and eigenvalue solvers preconditioned by the inverse Stokes operator and realized via time-stepping. First, we suggest a generalization of the Stokes operator so that the resulting preconditioner operator depends on several parameters and whose action preserves zero divergence and boundary conditions. The parameters can be tuned for each problem to speed up the convergence of a Krylov-subspace-based linear algebra solver. This operator can be inverted by the Uzawa-like algorithm, and does not need a time-stepping. Second, we propose to generate an initial guess of steady flow, leading eigenvalue and eigenvector using orthogonal projection on a divergence-free basis satisfying all boundary conditions. The approach, including the two proposed techniques, is illustrated on the solution of the linear stability problem for laterally heated square and cubic cavities

    Effectiveness of dry needling on reducing pain intensity in patients with myofascial pain syndrome: a Meta-analysis

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    AbstractObjectiveTo summarize the literature about the effectiveness of dry needling (DN) on relieving pain and increasing range of motion (ROM) in individuals with myofascial pain syndrome (MPS).MethodsPapers published from January 2000 to January 2013 were identified through an electronic search in the databases MEDLINE, Dialnet, Cochrane Library Plus, Physiotherapy Evidence Database (PEDro) and Spanish Superior Council of Scientific Research (CSIC). The studies included were randomized controlled trials written in English and/or Spanish about the effectiveness of DN on pain and ROM in individuals with MPS.ResultsOut of 19 clinical trials that were potentially relevant, a total of 10 were included in the Meta-analysis. Regarding pain intensity reduction when measured before and immediately after the intervention, DN achieved improvement compared with the placebo treatment [d = − 0.49; 95% CI (− 3.21, 0.42)] and with the control group [d = − 9.13; 95% CI (− 14.70, − 3.56)]. However, other treatments achieved better results on the same variable compared with DN, considering the measurements for pre-treatment and immediately after [d = 2.54; 95% CI (− 0.40, 5.48)], as well as the pre-treatment and after 3-4 weeks [d = 4.23; 95% CI (0.78, 7.68)]. DN showed a significantly increased ROM when measured before the intervention and immediately after, in comparison with the placebo [d = 2.00; 95% CI (1.60, 2.41)]. However, other treatments achieved a significant better result regarding ROM when it was measured before the intervention and immediately after, as compared with DN [d = −1.42; 95% CI (− 1.84, − 0.99)].ConclusionDN was less effective on decreasing pain comparing to the placebo group. Other treatments were more effective than DN on reducing pain after 3-4 weeks. However, on increasing ROM, DN was more effective comparing to that of placebo group, but less than other treatments

    Ecosystem service provision by marine habitats in Southeast Asia

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    Southeast Asia is an area of rich marine biodiversity providing a host of ecosystem services that contribute to the well-being of coastal communities and beyond. Sustainable management of ecosystems and the services they provide requires a good understanding of their underlying ecological functions and processes. This understanding can be gained through the rigorous assessment of studies identifying and quantifying ecological functions and ecosystem services. The aims of this study were to review the ecosystem services provided by marine and coastal habitats in Southeast Asia. The ecosystem service potential was scored for each habitat. The review was focused on nine key marine and coastal habitats, identified across four case study sites in Southeast Asia, contributing 18 marine relevant ecosystem services. The approach comprised a literature review supplemented with observations from experts from the case study areas. The four case study sites consist of three Man and Biosphere Reserves in Southeast Asia: Palawan in the Philippines, Cu Lao Cham- Hoi An in Viet Nam, Take-Bonerate Kepulauan Selayar in Indonesia, and a recently gazetted marine protected area, the Tun Mustapha Marine Park in Malaysia (Figure 1). The nine key habitats (eight benthic and one pelagic) covered in this review, identified as highly relevant for most case study sites, were mangrove forests, coral reefs, seagrass meadows, sand, mud, rock, coarse substratum, pelagic and modified habitats. Further division of these habitats into sub-habitats on the basis of biological type and substrate type was used to capture data on differential provision of ecosystem services within the broad habitat types. To ensure relevance in the four case study sites, firstly an ecosystem services typology was created tailored to these sites. After exploring several ecosystem service typologies, our final classification was adapted from the Common International Classification of Ecosystem services (CICES) V4.3 because it was considered to be most relevant to the objectives of this task. Provisioning, regulation and maintenance, and cultural services were assessed. Provisioning services focused on food for consumption by humans from plants, pelagic animals, demersal fish and invertebrates; energy from harvested plants; other materials from plants and animals, such as fibres, building and housing materials, medicines, decoration, handicrafts and souvenirs; and genetic material from plants and animals (including seeds, spat, spores, whole plants or animals, individual genes), for example seed or brood-stock collection for aquaculture and mangrove replanting and new plantations. Regulation and maintenance services assessed were treatment and assimilation of wastes or toxic substances; coastal erosion control; water flow regulation contributing to dampening the intensity of storm, floods, tsunamis, and hurricanes and the maintenance of localized water flows such as coastal current structures; maintenance of nursery,reproduction and feeding habitats; maintenance of critical habitats for charismatic species such as turtles, dugongs, cetaceans, sharks, seahorses, bats, fireflies, birds, monkeys, orchids and other epiphytes; and climate regulation through impacts on the hydrological cycle, temperature regulation, and the contribution to regulation of climate-influencing gases in the atmosphere, for example through carbon sequestration and long-term, decadal storage. Cultural services examined included uses of habitats as places for active and passive recreation; ceremonial activities; creative activities; and knowledge-based activities, such as educational activities, and citizen science or community environmental activities. The comprehensive literature review included peer-reviewed scientific research literature as well as grey literature such as government and other reports. To ensure a wide breadth of coverage, the research focused on studies from Southeast Asia. When no evidence was found in the literature, evidence was sought from experts, and where useful, was accompanied by observations from the authors in their respective case study sites. The evidence gathered was used to assess the potential of each habitat to provide an ecosystem service, rather than to assess the actual provision of ecosystem services from each case study site. This important distinction allows the differentiation between services provided by the ecosystem (i.e. the potential supply of ecosystem services that a habitat could deliver) and (achieved or used) benefits (i.e. the demand for ecosystem services). The knowledge gained from the literature, local and regional reports, together with observations from the study team and experts, was critically assessed using a robust methodology that captured different types of information together with a confidence score for the supporting evidence. The contribution of each habitat to each ecosystem service was then scored relative to other habitats. Our objective was to provide baseline information to enable better understanding of the ecosystem services arising from marine and coastal habitats in SE Asia. This provides a foundation for future assessments of natural capital and ecosystem services which may be used to inform sustainable management. The report will serve as a useful reference to many different readers. Regulators, managers of marine sites and policy makers might use this report to inform their management choices. This should enable more sustainable use of the marine environment and maximise the ecosystem service provision of all types of services addressed in this study. Stakeholders of the marine environment such as fisherfolk or residents might use this report to help them engage in management processes, to gain deeper understanding of the marine environment or confirm their observations of the marine environment. Academics can use it as a reference source or a base for further studies, in particular for valuation studies or when considering the trade-offs between ecosystem services in marine and coastal habitats. Finally, it is hoped that this report may bring a new appreciation and understanding of the marine environment and the life support it provides to society and inspire readers to improve management of the marine environment. This report is one of the outputs of the UK Research and Innovation’s Global Challenges Research Fund (UKRI GCRF) Blue Communities Programme (GCRF Blue Communities Global Challenges Research Fund via the United Kingdom Research and Innovation (UKRI) under grant agreement reference NE/P021107/1, www.blue-communities.org), which aims to “build capacity for sustainable interactions with marine ecosystems for the benefit of the health, well-being, food security and livelihoods of coastal communities in SE Asia”. GCRF Blue Communities is developing interdisciplinary research capability and lasting collaborations that can facilitate innovative application of integrated planning in the marine environment and respond to the UN Sustainable Development Goals of ‘no poverty’, ‘zero hunger’, ‘good health and well-being’ for coastal communities as well as ‘conserve and sustainably use the oceans, seas and marine resources for sustainable development’ through the sustainable use of marine resources

    ARES. III. Unveiling the Two Faces of KELT-7 b with HST WFC3*

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    We present the analysis of the hot-Jupiter KELT-7 b using transmission and emission spectroscopy from the Hubble Space Telescope, both taken with the Wide Field Camera 3. Our study uncovers a rich transmission spectrum that is consistent with a cloud-free atmosphere and suggests the presence of H_{2}O and H^{−}. In contrast, the extracted emission spectrum does not contain strong absorption features and, although it is not consistent with a simple blackbody, it can be explained by a varying temperature–pressure profile, collision induced absorption, and H^{-}. KELT-7 b had also been studied with other space-based instruments and we explore the effects of introducing these additional data sets. Further observations with Hubble, or the next generation of space-based telescopes, are needed to allow for the optical opacity source in transmission to be confirmed and for molecular features to be disentangled in emission

    Research cardiac magnetic resonance imaging in end stage renal disease - incidence, significance and implications of unexpected incidental findings

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    Objectives: Left ventricular mass (LVM) at cardiac magnetic resonance imaging (CMR) is a frequent end point in clinical trials in nephrology. Trial participants with end stage renal disease (ESRD) may have a greater frequency of incidental findings (IF). We retrospectively investigated prevalence of IF in previous research CMR and reviewed their subsequent impact on participants. Methods: Between 2002 and 2006, 161 ESRD patients underwent CMR in a transplant assessment study. Images were used to assess LV mass and function. In the current study a radiologist reviewed the scans for IF. Review of patient records determined the subsequent clinical significance of IF. Results: There were 150 IF in 95 study participants. Eighty-four (56 %) were new diagnoses. One hundred and two were non-cardiac. Fifteen were suspicious of malignancy. There was a clinically significant IF for 14.9 % of the participants. In six cases earlier identification of an IF may have improved quality of life or survival. Conclusions: Without radiology support clinically important IF may be missed on CMR. Patients undergoing CMR in trials should be counselled about the frequency and implications of IF. Patients with ESRD have a higher prevalence of IF than reported in other populations. Nephrology studies require mechanisms for radiologist reporting and strategies for dealing with IF

    HTLV-1-Associated Adult T Cell Leukemia Lymphoma Presenting as Granulomatous Pneumocystis Jiroveci Pneumonia (PJP) and Hypercalcemia

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    BACKGROUND: Since the initial description of human T cell lymphotropic virus (HTLV-1), clusters of this infection have been detected globally. Unlike HIV infection, most patients infected with HTLV-1 remain asymptomatic throughout their lifetime. CASE REPORT: We report the case of a 39-year-old Afro-Caribbean man with HTLV-1 infection presenting as hypercalcemia and granulomatous pneumocystis jiroveci pneumonia. RESULTS: Interestingly, the hypercalcemia presented with normal parathyroid hormone–related protein and low 1,25 dihydroxyvitamin D levels, and the presence of pneumocystis jiroveci in the granulomas was diagnosed with transbronchial biopsy taken during bronchoscopy. HTLV-1-associated adult T cell leukemia lymphoma (ATLL) was diagnosed in this patient by bone marrow and lymph node biopsy. CONCLUSION: Increased bone resorption, likely cytokine-mediated, is the most likely mechanism of hypercalcemia in this patient. This is believed to be the first description of this type of reaction to pneumocystis jiroveci in a HTLV-1-infected ATLL patient

    A search for the decay modes B+/- to h+/- tau l

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    We present a search for the lepton flavor violating decay modes B+/- to h+/- tau l (h= K,pi; l= e,mu) using the BaBar data sample, which corresponds to 472 million BBbar pairs. The search uses events where one B meson is fully reconstructed in one of several hadronic final states. Using the momenta of the reconstructed B, h, and l candidates, we are able to fully determine the tau four-momentum. The resulting tau candidate mass is our main discriminant against combinatorial background. We see no evidence for B+/- to h+/- tau l decays and set a 90% confidence level upper limit on each branching fraction at the level of a few times 10^-5.Comment: 15 pages, 7 figures, submitted to Phys. Rev.

    Evidence for an excess of B -> D(*) Tau Nu decays

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    Based on the full BaBar data sample, we report improved measurements of the ratios R(D(*)) = B(B -> D(*) Tau Nu)/B(B -> D(*) l Nu), where l is either e or mu. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D) = 0.440 +- 0.058 +- 0.042 and R(D*) = 0.332 +- 0.024 +- 0.018, which exceed the Standard Model expectations by 2.0 sigma and 2.7 sigma, respectively. Taken together, our results disagree with these expectations at the 3.4 sigma level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model. We also report the observation of the decay B -> D Tau Nu, with a significance of 6.8 sigma.Comment: Expanded section on systematics, text corrections, improved the format of Figure 2 and included the effect of the change of the Tau polarization due to the charged Higg
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