965 research outputs found

    Malaria-filaria coinfection in mice makes malarial disease more severe unless filarial infection achieves patency

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    Coinfections are common in natural populations, and the literature suggests that helminth coinfection readily affects how the immune system manages malaria. For example, type 1–dependent control of malaria parasitemia might be impaired by the type 2 milieu of preexisting helminth infection. Alternatively, immunomodulatory effects of helminths might affect the likelihood of malarial immunopathology. Using rodent models of lymphatic filariasis (Litomosoides sigmodontis) and noncerebral malaria (clone AS Plasmodium chabaudi chabaudi), we quantified disease severity, parasitemia, and polyclonal splenic immune responses in BALB/c mice. We found that coinfected mice, particularly those that did not have microfilaremia (Mf), had more severe anemia and loss of body mass than did mice with malaria alone. Even when controlling for parasitemia, malaria was most severe in Mf coinfected mice, and this was associated with increased interferon-g responsiveness. Thus, in Mf mice, filariasis upset a delicate immunological balance in malaria infection and exacerbated malaria-induced immunopathology. Helminth infections are prevalent throughout tropical regions where malaria is transmitted [1–5]. Interactions among infections commonly alter disease severity [6, 7], and malaria-helminth coinfection can either exac

    Time-to-Contact and Collision-Detection Estimations as Measures of Driving Safety in Old and Dementia Drivers

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    The paper discusses the importance of Time-to-Contact (TTC) and collision occurrence (CD) estimations for safe driving. It describes a computerised testing tool that requires TTC and CD estimations while dividing attention and discusses the association between performance on this task and several measures of driving safety. We report four studies showing that the task is sensitive to age effects and dementia effects, that the accuracy of Time-to-Contact estimations differentiates between old and dementia drivers recently involved in accidents and those not involved. We also found an association between performance on this task and that on navigation and car following tasks in a driving simulator

    Alterations in Mosquito Behaviour by Malaria Parasites: Potential Impact on Force of Infection

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    A variety of studies have reported that malaria parasites alter the behaviour of mosquitoes. These behavioural alterations likely increase transmission because they reduce the risk of vector death during parasite development and increase biting after parasites become infectious. A mathematical model is used to investigate the potential impact of these behavioural alterations on the lifetime number of infectious bites delivered. The model is used to explore the importance of assumptions about the magnitude and distribution of mortality as well as the importance of extrinsic incubation period and gonotrophic cycle length. Additionally, the model is applied to four datasets taken from actual transmission settings. The impact of behavioural changes on the relative number of lifetime bites is highly dependent on assumptions about the distribution of mortality over the mosquito-feeding cycle. Even using fairly conservative estimates of these parameters and field collected data, the model outputs suggest that altered feeding could easily cause a doubling in the force of infection.Infection-iduced behavioural alterations have their greatest impact on the lifetime number of infectious bites in environments with high feeding-related adult mortality and many pre-infectious feeding cycles. Interventions that increase feeding-associated mortality are predicted to amplify the relative fitness benefits and hence enhance the strength of selection for behavioural alteration\u

    Penetration Testing and Vulnerability Assessments: A Professional Approach

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    Attacks against computer systems and the data contained within these systems are becoming increasingly frequent and evermore sophisticated. So-called “zero-day” exploits can be purchased on black markets and Advanced Persistent Threats (APTs) can lead to exfiltration of data over extended periods. Organisations wishing to ensure security of their systems may look towards adopting appropriate measures to protect themselves against potential security breaches. One such measure is to hire the services of penetration testers (or “pen-tester”) to find vulnerabilities present in the organisation’s network, and provide recommendations as to how best to mitigate such risks. This paper discusses the definition and role of the modern pen-tester and summarises current standards and professional qualifications in the UK. The paper further identifies issues arising from pen-testers, highlighting differences from what is generally expected of their role in industry to what is demanded by professional qualifications

    Evolutionary History and Attenuation of Myxoma Virus on Two Continents

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    The attenuation of myxoma virus (MYXV) following its introduction as a biological control into the European rabbit populations of Australia and Europe is the canonical study of the evolution of virulence. However, the evolutionary genetics of this profound change in host-pathogen relationship is unknown. We describe the genome-scale evolution of MYXV covering a range of virulence grades sampled over 49 years from the parallel Australian and European epidemics, including the high-virulence progenitor strains released in the early 1950s. MYXV evolved rapidly over the sampling period, exhibiting one of the highest nucleotide substitution rates ever reported for a double-stranded DNA virus, and indicative of a relatively high mutation rate and/or a continually changing selective environment. Our comparative sequence data reveal that changes in virulence involved multiple genes, likely losses of gene function due to insertion-deletion events, and no mutations common to specific virulence grades. Hence, despite the similarity in selection pressures there are multiple genetic routes to attain either highly virulent or attenuated phenotypes in MYXV, resulting in convergence for phenotype but not genotype. © 2012 Kerr et al

    Hidden Markov models reveal complexity in the diving behaviour of short-finned pilot whales

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    This work was supported by award RC-2154 from the Strategic Environmental Research and Development Program and funding from the Naval Facilities Engineering Command Atlantic and NOAA Fisheries, Southeast Region. DS was supported by the United States Office of Naval Research grant N00014-12-1-0204, under the project entitled Multi-study Ocean acoustics Human effects Analysis (MOCHA).Diving behaviour of short-finned pilot whales is often described by two states; deep foraging and shallow, non-foraging dives. However, this simple classification system ignores much of the variation that occurs during subsurface periods. We used multi-state hidden Markov models (HMM) to characterize states of diving behaviour and the transitions between states in short-finned pilot whales. We used three parameters (number of buzzes, maximum dive depth and duration) measured in 259 dives by digital acoustic recording tags (DTAGs) deployed on 20 individual whales off Cape Hatteras, North Carolina, USA. The HMM identified a four-state model as the best descriptor of diving behaviour. The state-dependent distributions for the diving parameters showed variation between states, indicative of different diving behaviours. Transition probabilities were considerably higher for state persistence than state switching, indicating that dive types occurred in bouts. Our results indicate that subsurface behaviour in short-finned pilot whales is more complex than a simple dichotomy of deep and shallow diving states, and labelling all subsurface behaviour as deep dives or shallow dives discounts a significant amount of important variation. We discuss potential drivers of these patterns, including variation in foraging success, prey availability and selection, bathymetry, physiological constraints and socially mediated behaviour.Publisher PDFPeer reviewe

    Book reviews

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    Reviews of the following items: Excellence in coaching: the industry guide. Edited by Jonathan Passmore. London: Kogan Page, 2010. ISBN 978-0-7494-5667-2. Doing your PGCE at M-level: a guide for students. Edited by Keira Sewell. London: Sage, 2012. ISBN 978-1-4462-0830-4. Contemporary issues in learning and teaching. Edited by Margery McMahon, Christine Forde and Margaret Martin. London: Sage, 2011. ISBN 978-1-84920-128-5. Using museums as an educational resource: an introductory handbook for students and teachers. Graeme Talboys. Aldershot: Ashgate Publishing, 2010. ISBN: 978-1-4094-0145-2

    Reproductive Failure in UK Harbour Porpoises Phocoena phocoena : Legacy of Pollutant Exposure?

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    This research was supported by a Marie Curie International Outgoing Fellowship within the Seventh European Community Framework Programme (Project Cetacean-stressors, PIOF-GA-2010-276145 to PDJ and SM). Additional funding was provided through the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS) (Grants SSFA/2008 and SSFA / ASCOBANS / 2010 / 5 to SM). Analysis of Scottish reproductive and teeth samples was funded by the EC-funded BIOCET project (BIOaccumulation of persistent organic pollutants in small CETaceans in European waters: transport pathways and impact on reproduction, grant EVK3-2000-00027 to GJP), and Marine Scotland (GJP). Samples examined in this research were collected under the collaborative Cetacean Strandings Investigation Programme (http://ukstrandings.org/), which is funded by the Department for Environment, Food and Rural Affairs (Defra) and the UK’s Devolved Administrations in Scotland and Wales (http://sciencesearch.defra.gov.uk/Defaul​t.aspx?Menu=Menu&Module=More&Location=No​ne&Completed=0&ProjectID=15331) (grants to PDJ, RD). UK Defra also funded the chemical analysis under a service-level agreement with the Centre for Environment, Fisheries and Aquaculture Science (grants to RJL, JB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Building an eScience Thesaurus for Librarians: A Collaboration Between the National Network of Libraries of Medicine, New England Region and an Associate Fellow at the National Library of Medicine

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    Objective: In response to the growing interest and adoption of eScience roles by librarians, those from the National Network of Libraries of Medicine, New England Region (NN/LM NER) and an Associate Fellow from the National Library of Medicine collaborated to build an eScience Thesaurus. The Thesaurus will introduce librarians to terminology and concepts in eScience, point to relevant literature and resources on data and digital research topics, and provide links to interviews with librarians and experts working in eScience-related roles. The eScience Thesaurus is a starting place for librarians to find the vocabulary to research the background, resources, and tools necessary for developing their capacity to provide eScience-related services. Methods: The Associate Fellow completed a review of eScience-related literature to identify the seminal publications for the originations of these terms and concepts as they apply to libraries. Next, the Associate Fellow worked with the NN/LM NER to compile an environmental scan of resources that would be useful and applicable for librarians, and created a scope document and record structure. The team interviewed prominent librarians working in eScience roles and experts that have created digital tools and services used by the library community. Finally, the team sent the Thesaurus records out to five members of the advisory and editorial review boards from the eScience Portal for New England Librarians for evaluation. Results: The eScience Thesaurus is now hosted on the eScience Portal for New England Librarians’ website. It provides a comprehensive list of more than 50 different terminologies and concepts, with links to seminal and relevant literature, resources, grants, and interviews on a variety of eScience-related topics. Conclusion: The eScience Thesaurus is an evolving resource; as the field expands and more eScience-related terms are adopted by the library and information science community, the Portal will enable its users to electronically submit new vocabulary and records to the Thesuarus, thus preserving it as a go-to eScience resource for librarians
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