823 research outputs found
Formation, evolution and multiplicity of brown dwarfs and giant exoplanets
This proceeding summarises the talk of the awardee of the Spanish
Astronomical Society award to the the best Spanish thesis in Astronomy and
Astrophysics in the two-year period 2006-2007. The thesis required a tremendous
observational effort and covered many different topics related to brown dwarfs
and exoplanets, such as the study of the mass function in the substellar domain
of the young sigma Orionis cluster down to a few Jupiter masses, the relation
between the cluster stellar and substellar populations, the accretion discs in
cluster brown dwarfs, the frequency of very low-mass companions to nearby young
stars at intermediate and wide separations, or the detectability of Earth-like
planets in habitable zones around ultracool (L- and T-type) dwarfs in the solar
neighbourhood.Comment: "Highlights of Spanish Astrophysics V", Proceedings of the VIII
Scientific Meeting of the Spanish Astronomical Society (SEA) held in
Santander, 7-11 July, 2008. Edited by J. Gorgas, L. J. Goicoechea, J. I.
Gonzalez-Serrano, J. M. Diego. Invited oral contribution to plenary sessio
Truth or precision? Some reflections on the economists’ failure to predict the financial crisis
The failure of professional economic forecasters to predict the financial crises has led many to question the credibility of modern economics as a reliable foundation for economic policy. If economists were unable to foresee so big a crisis, how can they be trusted to cure or prevent it? Several accounts of this failure exist. The paper offers a tentative answer based on the lessons that may be drawn from the wisdom of a short list of past and present economists: Hayek, Neville Keynes, Mankiw, Tinbergen, Maynard Keynes and Lucas. The glue to keep such an odd bunch together is the distinction between truth and precision provided by science historian Ted Porter
The RING-CH ligase K5 antagonizes restriction of KSHV and HIV-1 particle release by mediating ubiquitin-dependent endosomal degradation of tetherin
Tetherin (CD317/BST2) is an interferon-induced membrane protein that inhibits the release of diverse enveloped viral particles. Several mammalian viruses have evolved countermeasures that inactivate tetherin, with the prototype being the HIV-1 Vpu protein. Here we show that the human herpesvirus Kaposi's sarcoma-associated herpesvirus (KSHV) is sensitive to tetherin restriction and its activity is counteracted by the KSHV encoded RING-CH E3 ubiquitin ligase K5. Tetherin expression in KSHV-infected cells inhibits viral particle release, as does depletion of K5 protein using RNA interference. K5 induces a species-specific downregulation of human tetherin from the cell surface followed by its endosomal degradation. We show that K5 targets a single lysine (K18) in the cytoplasmic tail of tetherin for ubiquitination, leading to relocalization of tetherin to CD63-positive endosomal compartments. Tetherin degradation is dependent on ESCRT-mediated endosomal sorting, but does not require a tyrosine-based sorting signal in the tetherin cytoplasmic tail. Importantly, we also show that the ability of K5 to substitute for Vpu in HIV-1 release is entirely dependent on K18 and the RING-CH domain of K5. By contrast, while Vpu induces ubiquitination of tetherin cytoplasmic tail lysine residues, mutation of these positions has no effect on its antagonism of tetherin function, and residual tetherin is associated with the trans-Golgi network (TGN) in Vpu-expressing cells. Taken together our results demonstrate that K5 is a mechanistically distinct viral countermeasure to tetherin-mediated restriction, and that herpesvirus particle release is sensitive to this mode of antiviral inhibition
Selection of diazotrophic bacterial communities in biological sand filter mesocosms used for the treatment of phenolic-laden wastewater
Agri effluents such as winery or olive mill waste-waters are characterized by high phenolic concentrations. These compounds are highly toxic and generally refractory to biodegradation. Biological sand filters (BSFs) represent inexpensive, environmentally friendly, and sustainable wastewater treatment systems which rely vastly on microbial catabolic processes. Using denaturing gradient gel electrophoresis and terminal-restriction fragment length polymorphism, this study aimed to assess the impact of increasing concentrations of synthetic phenolic-rich wastewater, ranging from 96 mg L−1 gallic acid and138 mg L−1 vanillin (i.e., a total chemical oxygen demand (COD) of 234 mg L−1) to 2,400mg L−1 gallic acid and 3,442 mg L−1 vanillin (5,842 mg COD L−1), on bacterialcommunities and the specific functional diazotrophic community from BSF mesocosms. This amendment procedure instigated efficient BSF phenolic removal, significant modifications of the bacterial communities, and notably led to the selection of a phenolic-resistant and less diverse diazotrophic community. This suggests that bioavailable N is crucial in the functioning of biological treatment processes involving microbial communities, and thus that functional alterations in the bacterial communities in BSFs ensure provision of sufficient bioavailable nitrogen for the degradation of wastewater with a high C/N ratio.Web of Scienc
An e-health driven laboratory information system to support HIV treatment in Peru: E-quity for laboratory personnel, health providers and people living with HIV
<p>Abstract</p> <p>Background</p> <p>Peru has a concentrated HIV epidemic with an estimated 76,000 people living with HIV (PLHIV). Access to highly active antiretroviral therapy (HAART) expanded between 2004-2006 and the Peruvian National Institute of Health was named by the Ministry of Health as the institution responsible for carrying out testing to monitor the effectiveness of HAART. However, a national public health laboratory information system did not exist. We describe the design and implementation of an e-health driven, web-based laboratory information system - NETLAB - to communicate laboratory results for monitoring HAART to laboratory personnel, health providers and PLHIV.</p> <p>Methods</p> <p>We carried out a needs assessment of the existing public health laboratory system, which included the generation and subsequent review of flowcharts of laboratory testing processes to generate better, more efficient streamlined processes, improving them and eliminating duplications. Next, we designed NETLAB as a modular system, integrating key security functions. The system was implemented and evaluated.</p> <p>Results</p> <p>The three main components of the NETLAB system, registration, reporting and education, began operating in early 2007. The number of PLHIV with recorded CD4 counts and viral loads increased by 1.5 times, to reach 18,907. Publication of test results with NETLAB took an average of 1 day, compared to a pre-NETLAB average of 60 days. NETLAB reached 2,037 users, including 944 PLHIV and 1,093 health providers, during its first year and a half. The percentage of overall PLHIV and health providers who were aware of NETLAB and had a NETLAB password has also increased substantially.</p> <p>Conclusion</p> <p>NETLAB is an effective laboratory management tool since it is directly integrated into the national laboratory system and streamlined existing processes at the local, regional and national levels. The system also represents the best possible source of timely laboratory information for health providers and PLHIV, allowing patients to access their own results and other helpful information about their health, extending the scope of HIV treatment beyond the health facility and providing a model for other countries to follow. The NETLAB system now includes 100 diseases of public health importance for which the Peruvian National Institute of Health and the network of public health laboratories provide testing and results.</p
All-sky visible and near infrared space astrometry
The era of all-sky space astrometry began with the Hipparcos mission in 1989 and provided the first very accurate catalogue of apparent magnitudes, positions, parallaxes and proper motions of 120 000 bright stars at the milliarcsec (or milliarcsec per year) accuracy level. Hipparcos has now been superseded by the results of the Gaia mission. The second Gaia data release contained astrometric data for almost 1.7 billion sources with tens of microarcsec (or microarcsec per year) accuracy in a vast volume of the Milky Way and future data releases will further improve on this. Gaia has just completed its nominal 5-year mission (July 2019), but is expected to continue in operations for an extended period of an additional 5 years through to mid 2024. Its final catalogue to be released ∼ 2027, will provide astrometry for ∼ 2 billion sources, with astrometric precisions reaching 10 microarcsec. Why is accurate astrometry so important? The answer is that it provides fundamental data which underpin much of modern observational astronomy as will be detailed in this White Paper. All-sky visible and Near-InfraRed (NIR) astrometry with a wavelength cutoff in the K-band is not just focused on a single or small number of key science cases. Instead, it is extremely broad, answering key science questions in nearly every branch of astronomy while also providing a dense and accurate visible-NIR reference frame needed for future astronomy facilities
The role of emergency neurology in Italy: outcome of a consensus meeting for a intersociety position
A possible definition of clinical, educational and organizing aspects of emergency neurology in Italy is reported in this position paper of Emergency Neurology Intersociety Group, created in 2008 among the two neurological Societies in Italy: Società Italiana di Neurologia and Società di Neuroscienze Ospedaliere. The aim of this Group has been the evaluation of the role of neurologist in the emergency setting of Italian hospitals, as well as of the description of different scenarios in which a ward dedicated to a semi-intensive care of neurological emergencies could have a role in the actual organization of academic or general hospitals in our Country. The actual great relevance of neurologist activity in the inpatients treatment, in fact, is actually misleaded as it is the considerable significance of neurological expertise, techniques and support in hospital care pathways also involving neurological manifestations throughout the course of other diseases. Finally, the possible contents of educational programs orienting neurological specialty towards a better comprehension and management of emergency neurological problems either in terms of specific formation or of techniques to be learned by emergency neurologist, are reported as a results of the Consensus Workshop hold in Castiglioncello (LI) in September 12th, 2009
A quantitative polymerase chain reaction-enzyme immunoassay for accurate measurements of human papillomavirus type 16 DNA levels in cervical scrapings
A quantitative polymerase chain reaction-enzyme immunoassay (Q-PCR-EIA) was developed to measure the amount of human papillomavirus (HPV) 16 DNA per genome equivalent in cervical scrapings. The quantitative approach was based on a combined competitive PCR for both HPV 16, using the general primer GP5+/6+ PCR, and β-globin DNA. The two competitive PCRs involve co-amplification of target sequences and exogenously added DNA constructs carrying a rearranged 30 bp sequence in the probe-binding region. The accuracy of quantification by combining the two competitive PCR assays was validated on mixtures of HPV 16 containing cervical cancer cells of CaSki and SiHa cell lines. Comparison of this fully quantitative PCR assay with two semi-quantitative HPV PCR assays on a series of crude cell suspensions from HPV 16 containing cervical scrapings revealed remarkable differences in the calculated relative HPV load between samples. We found evidence that correction for both intertube variations in PCR efficiency and number of input cells/integrity of DNA significantly influence the outcome of studies on viral DNA load in crude cell suspensions of cervical scrapings. Therefore, accurate measurements on viral DNA load in cervical scrapings require corrections for these phenomena, which can be achieved by application of this fully quantitative approach. © 1999 Cancer Research Campaig
The Political Economy of Non-Traditional Security: Explaining the Governance of Avian Influenza in Indonesia
Given the common association of non-traditional security (NTS) problems with globalisation, surprisingly little attention has been paid to how the political economy context of given NTS issues shape how they are securitised and managed in practice. We argue that security and its governance are always highly contested because different modes of security governance invariably privilege particular interests and normative agendas in state and society, which relate directly to the political economy. Drawing on critical political geography, we argue that, because NTS issues are perceived as at least potentially transnational, their securitisation often involves strategic attempts by actors and coalitions to ‘rescale’ their governance beyond the national political and institutional arenas, into new, expert-dominated modes of governance. Such efforts are often resisted by other coalitions, for which this rescaling is deleterious. As evidenced by a case study of avian influenza in Indonesia, particular governance outcomes depend upon the nature of the coalitions assembled for and against rescaling in specific situations, while these coalitions’ make-up and relative strength is shaped by the political economy of the industries that rescaling would affect, viewed against the broader backdrop of state-society relations
How does study quality affect the results of a diagnostic meta-analysis?
Background: The use of systematic literature review to inform evidence based practice in diagnostics is rapidly expanding. Although the primary diagnostic literature is extensive, studies are often of low methodological quality or poorly reported. There has been no rigorously evaluated, evidence based tool to assess the methodological quality of diagnostic studies. The primary objective of this study was to determine the extent to which variations in the quality of primary studies impact the results of a diagnostic meta-analysis and whether this differs with diagnostic test type. A secondary objective was to contribute to the evaluation of QUADAS, an evidence-based tool for the assessment of quality in diagnostic accuracy studies. Methods: This study was conducted as part of large systematic review of tests used in the diagnosis and further investigation of urinary tract infection (UTI) in children. All studies included in this review were assessed using QUADAS, an evidence-based tool for the assessment of quality in systematic reviews of diagnostic accuracy studies. The impact of individual components of QUADAS on a summary measure of diagnostic accuracy was investigated using regression analysis. The review divided the diagnosis and further investigation of UTI into the following three clinical stages: diagnosis of UTI, localisation of infection, and further investigation of the UTI. Each stage used different types of diagnostic test, which were considered to involve different quality concerns. Results: Many of the studies included in our review were poorly reported. The proportion of QUADAS items fulfilled was similar for studies in different sections of the review. However, as might be expected, the individual items fulfilled differed between the three clinical stages. Regression analysis found that different items showed a strong association with test performance for the different tests evaluated. These differences were observed both within and between the three clinical stages assessed by the review. The results of regression analyses were also affected by whether or not a weighting (by sample size) was applied. Our analysis was severely limited by the completeness of reporting and the differences between the index tests evaluated and the reference standards used to confirm diagnoses in the primary studies. Few tests were evaluated by sufficient studies to allow meaningful use of meta-analytic pooling and investigation of heterogeneity. This meant that further analysis to investigate heterogeneity could only be undertaken using a subset of studies, and that the findings are open to various interpretations. Conclusion: Further work is needed to investigate the influence of methodological quality on the results of diagnostic meta-analyses. Large data sets of well-reported primary studies are needed to address this question. Without significant improvements in the completeness of reporting of primary studies, progress in this area will be limited
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