649 research outputs found

    Quantum Measurement and the Aharonov-Bohm Effect with Superposed Magnetic Fluxes

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    We consider the magnetic flux in a quantum mechanical superposition of two values and find that the Aharonov-Bohm effect interference pattern contains information about the nature of the superposition, allowing information about the state of the flux to be extracted without disturbance. The information is obtained without transfer of energy or momentum and by accumulated nonlocal interactions of the vector potential A⃗\vec{A} with many charged particles forming the interference pattern, rather than with a single particle. We suggest an experimental test using already experimentally realized superposed currents in a superconducting ring and discuss broader implications.Comment: 6 pages, 4 figures; Changes from version 3: corrected typo (not present in versions 1 and 2) in Eq. 8; Changes from version 2: shortened abstract; added refs and material in Section IV. The final publication is available at: http://link.springer.com/article/10.1007/s11128-013-0652-

    Individual freedom versus collective responsibility: too many rights make a wrong?

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    Individuals might reasonably expect the freedom to make their own decisions regarding their health. However, what happens when an individual's wishes conflict with what is in that individual's best interests? How far should an individual's rights be restricted for his or her own benefit? Similarly, what limitations should be placed on an individual's behaviour when that person's wishes go against what is good for the population in general? Here we discuss the issues that can arise when the rights of individuals conflict with individual and population benefits in relation to infectious diseases

    Knock-in models related to Alzheimer’s disease: synaptic transmission, plaques and the role of microglia

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    Background: Microglia are active modulators of Alzheimer’s disease but their role in relation to amyloid plaques and synaptic changes due to rising amyloid beta is unclear. We add novel findings concerning these relationships and investigate which of our previously reported results from transgenic mice can be validated in knock-in mice, in which overexpression and other artefacts of transgenic technology are avoided. Methods: AppNL-F and AppNL-G-F knock-in mice expressing humanised amyloid beta with mutations in App that cause familial Alzheimer’s disease were compared to wild type mice throughout life. In vitro approaches were used to understand microglial alterations at the genetic and protein levels and synaptic function and plasticity in CA1 hippocampal neurones, each in relationship to both age and stage of amyloid beta pathology. The contribution of microglia to neuronal function was further investigated by ablating microglia with CSF1R inhibitor PLX5622. Results: Both App knock-in lines showed increased glutamate release probability prior to detection of plaques. Consistent with results in transgenic mice, this persisted throughout life in AppNL-F mice but was not evident in AppNL-G-F with sparse plaques. Unlike transgenic mice, loss of spontaneous excitatory activity only occurred at the latest stages, while no change could be detected in spontaneous inhibitory synaptic transmission or magnitude of long-term potentiation. Also, in contrast to transgenic mice, the microglial response in both App knock-in lines was delayed until a moderate plaque load developed. Surviving PLX5266-depleted microglia tended to be CD68-positive. Partial microglial ablation led to aged but not young wild type animals mimicking the increased glutamate release probability in App knock-ins and exacerbated the App knock-in phenotype. Complete ablation was less effective in altering synaptic function, while neither treatment altered plaque load. Conclusions: Increased glutamate release probability is similar across knock-in and transgenic mouse models of Alzheimer’s disease, likely reflecting acute physiological effects of soluble amyloid beta. Microglia respond later to increased amyloid beta levels by proliferating and upregulating Cd68 and Trem2. Partial depletion of microglia suggests that, in wild type mice, alteration of surviving phagocytic microglia, rather than microglial loss, drives age-dependent effects on glutamate release that become exacerbated in Alzheimer’s disease

    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

    Reliability of a 1-week recall period for the Medical Outcomes Study Sleep Scale (MOS-SS) in patients with fibromyalgia

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    <p>Abstract</p> <p>Objective</p> <p>To evaluate the reliability of a one-week versus a four-week recall period of the Medical Outcomes Study Sleep Scale (MOS-SS) in patients with fibromyalgia (FM).</p> <p>Methods</p> <p>The MOS-SS was administered by mail to patients with a confirmed diagnosis of FM and a current pain rating of > 2 (0–10 point numerical rating scale) recruited through newspapers, support groups, and the Internet. Reliability of MOS-SS subscale domains was evaluated using test-retest methodology separated by a 1–3 day interval for the 4-week recall period and a 7-day interval for the 1-week recall period. Patient Impression of Change was evaluated for sleep, and for patients with no change, the intraclass correlation coefficient (ICC) and the Pearson correlation coefficient was calculated for MOS-SS subscales.</p> <p>Results</p> <p>Of 129 patients enrolled, 91.3% were female, mean age was 49.4 ± 11.0 years; self-rated FM severity was moderate-to-severe in 88.1% of patients. MOS-SS subscale scores were similar for both recall periods with little variation between test-retest. The 9-item Sleep Problems Index scores ranged from 57.2 ± 14.5 to 61.9 ± 15.8 across all assessments and demonstrated high reliability which was similar for the 1-week (ICC 0.81) and 4-week (ICC 0.89) recall periods. For the other MOS-SS subscales, the 1-week recall period also showed good reliability, which was consistent for the ICC and Pearson correlation coefficients.</p> <p>Conclusion</p> <p>A 1-week recall period is adequately reliable for use of the MOS-SS in studies evaluating sleep disturbance in patients with FM.</p

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Search for high-mass resonances decaying to dilepton final states in pp collisions at s√=7 TeV with the ATLAS detector

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    The ATLAS detector at the Large Hadron Collider is used to search for high-mass resonances decaying to an electron-positron pair or a muon-antimuon pair. The search is sensitive to heavy neutral Z′ gauge bosons, Randall-Sundrum gravitons, Z * bosons, techni-mesons, Kaluza-Klein Z/γ bosons, and bosons predicted by Torsion models. Results are presented based on an analysis of pp collisions at a center-of-mass energy of 7 TeV corresponding to an integrated luminosity of 4.9 fb−1 in the e + e − channel and 5.0 fb−1 in the μ + μ −channel. A Z ′ boson with Standard Model-like couplings is excluded at 95 % confidence level for masses below 2.22 TeV. A Randall-Sundrum graviton with coupling k/MPl=0.1 is excluded at 95 % confidence level for masses below 2.16 TeV. Limits on the other models are also presented, including Technicolor and Minimal Z′ Models

    A Meta-Analysis of the Existing Knowledge of Immunoreactivity against Hepatitis C Virus (HCV)

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    Approximately 3% of the world population is infected by HCV, which represents a major global health challenge. Almost 400 different scientific reports present immunological data related to T cell and antibody epitopes derived from HCV literature. Analysis of all HCV-related epitope hosted in the Immune Epitope Database (IEDB), a repository of freely accessible immune epitope data, revealed more than 1500 and 1900 distinct T cell and antibody epitopes, respectively. The inventory of all data revealed specific trends in terms of the host and the HCV genotypes from which sequences were derived. Upon further analysis we found that this large number of epitopes reflects overlapping structures, and homologous sequences derived from different HCV isolates. To access and visualize this information we developed a novel strategy that assembles large sets of epitope data, maps them onto reference genomes and displays the frequency of positive responses. Compilation of the HCV immune reactivity from hundreds of different studies, revealed a complex and thorough picture of HCV immune epitope data to date. The results pinpoint areas of more intense reactivity or research activities at the level of antibody, CD4 and CD8 responses for each of the individual HCV proteins. In general, the areas targeted by the different effector immune functions were distinct and antibody reactivity was positively correlated with hydrophilicity, while T cell reactivity correlated with hydrophobicity. At the sequence level, epitopes frequently recognized by both T cell and B cell correlated with low variability, and our analysis thus highlighted areas of potential interest for practical applications. The human reactivity was further analyzed to pinpoint differential patterns of reactivity associated with acute versus chronic infection, to reveal the apparent impact of glycosylation on T cell, but not antibody responses, and to highlight a paucity of studies involved antibody epitopes associated with virus neutralization
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