740 research outputs found

    Understanding tradeoffs in incremental deployment of new network architectures

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    Despite the plethora of incremental deployment mechanisms proposed, rapid adoption of new network-layer protocols and architectures remains difficult as reflected by the widespread lack of IPv6 traffic on the Internet. We show that all de-ployment mechanisms must address four key questions: How to select an egress from the source network, how to select an ingress into the destination network, how to reach that egress, and how to reach that ingress. By creating a de-sign space that maps all existing mechanisms by how they answer these questions, we identify the lack of existing mech-anisms in part of this design space and propose two novel approaches: the “4ID ” and the “Smart 4ID”. The 4ID mech-anism utilizes new data plane technology to flexibly decide when to encapsulate packets at forwarding time. The Smart 4ID mechanism additionally adopts an SDN-style control plane to intelligently pick ingress/egress pairs based on a wider view of the local network. We implement these mech-anisms along with two widely used IPv6 deployment mech-anisms and conduct wide-area deployment experiments over PlanetLab. We conclude that Smart 4ID provide better overall performance and failure semantics, and that inno-vations in the data plane and control plane enable straight-forward incremental deployment

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    A novel method to detect unlabeled inorganic nanoparticles and submicron particles in tissue by sedimentation field-flow fractionation

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    A novel methodology to detect unlabeled inorganic nanoparticles was experimentally demonstrated using a mixture of nano-sized (70 nm) and submicron (250 nm) silicon dioxide particles added to mammalian tissue. The size and concentration of environmentally relevant inorganic particles in a tissue sample can be determined by a procedure consisting of matrix digestion, particle recovery by centrifugation, size separation by sedimentation field-flow fractionation (SdFFF), and detection by light scattering

    Cultivating equality: delivering just and sustainable food systems in a changing climate

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    T oday, the world faces a greater challenge perhaps than ever before: tackling hunger and malnutrition in the face of climate change and increasing natural resource scarcity. Civil society, governments, researchers, donors, and the private sector are simultaneously debating and collaborating to find solutions. But the dialogue is over-emphasizing food production. Improving yields is important, particularly in places where there is not enough food or where food producers live in poverty. But simply producing more is not enough to tackle hunger. Furthermore, acknowledging that lack of food is not the sole cause of hunger is important. Inequality shapes who has access to food and the resources to grow it and buy it. It governs who eats first and who eats worst. Inequality determines who can adapt more readily to a changing climate. Hunger and poverty are not an accident – they are the result of social and economic injustice and inequality at all levels, from household to global. The reality of inequality is no truer for anyone than it is for women – half the world’s population, with far less than their fair share of the world’s resources. If we are to achieve the new Sustainable Development Goal of ending hunger by 2030, we must address the underlying inequalities in food systems. In a changing climate, agriculture and food systems must be sustainable and productive – but our efforts cannot end there. They must be profitable for those for whom it is a livelihood; they must be equitable, to facilitate a level playing field in the market, to secure rights to resources for food producers, and to ensure access to nutritious food for all; they must be resilient to build the capacity of populations vulnerable to economic shocks, political instability, and increasing, climate-induced natural hazards to recover and still lift themselves out of poverty

    Gaps in the Hepatitis C Continuum of Care among Sex Workers in Vancouver, British Columbia: Implications for Voluntary Hepatitis C Virus Testing, Treatment and Care

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    BACKGROUND: Hepatitis C virus (HCV) eradication leads to reduced morbidity, mortality and transmission. Despite the disproportionate burden of HCV among sex workers, data regarding the HCV care continuum in this population remain negligible. METHODS: Using baseline data from an ongoing cohort of women sex workers in Vancouver (An Evaluation of Sex Workers’ Health Access, January 2010 to August 2013), the authors assessed HCV prevalence and engagement in the HCV care continuum within the past year. Multivariable logistic regression analyses were used to evaluate associations with recent (ie, in the past year) HCV testing. RESULTS: Among 705 sex workers, 302 (42.8%) were HCV seropositive. Of these, 22.5% were previously unaware of their HCV status, 41.7% had accessed HCV-related care, 13.9% were offered treatment and only 1.0% received treatment. Among 552 HCV-seronegative sex workers, only one-half (52.9%) reported a recent HCV test. In multivariable analysis, women who self-identified as a sexual/gender minority (adjusted OR [aOR] 1.89 [95% CI 1.11 to 3.24]), resided in the inner city drug use epicentre (aOR 3.19 [95%CI 1.78 to 5.73]) and used injection (aOR 2.00 [95% CI 1.19 to 3.34]) or noninjection drugs (aOR 1.95 [95% CI 1.00 to 3.78]) had increased odds of undergoing a recent HCV test, while immigrant participants (aOR 0.24 [95% CI 0.12 to 0.48]) had decreased odds. CONCLUSIONS: Despite a high burden of HCV among sex workers, large gaps in the HCV care continuum remain. Particularly concerning are the low access to HCV testing, with one-fifth of women living with HCV being previously unaware of their status, and the exceptionally low prevalence of HCV treatment. There is a critical need for further research to better understand and address barriers to engage in the HCV continuum for sex workers

    Pectic Oligosaccharides from Cranberry Prevent Quiescence and Persistence in the Uropathogenic Escherichia coli CFT073

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    Urinary tract infections (UTIs) caused by Escherichia coli create a large burden on healthcare and frequently lead to recurrent infections. Part of the success of E. coli as an uropathogenic bacterium can be attributed to its ability to form quiescent intracellular reservoirs in bladder cells and its persistence after antibiotic treatment. Cranberry juice and related products have been used for the prevention of UTIs with varying degrees of success. In this study, a group of cranberry pectic oligosaccharides (cPOS) were found to both inhibit quiescence and reduce the population of persister cells formed by the uropathogenic strain, CFT073. This is the first report detailing constituents of cranberry with the ability to modulate these important physiological aspects of uropathogenic E. coli. Further studies investigating cranberry should be keen to include oligosaccharides as part of the ‘active’ cocktail of chemical compounds

    A ‘near‐life experience’: lived experiences of spirituality from the perspective of people who have been subject to inpatient psychiatric care

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    Aims: To describe lived experiences of spirituality from the perspective of people who have been subject to inpatient psychiatric care and to interpret these experiences from an understanding of health as dialectical. Methods: After approval from a regional ethical board,eleven participants were recruited from two organisations for people with mental health problems. Participants were asked to narrate about spiritual experiences and occasions where such experiences had come close. The transcribed interviews were analysed by means of a phenomenological hermeneutical approach. Findings: A structural analysis of the text resulted in three themes; perceiving the presence of something extra mundane, making sense of reality and struggling for acceptance. The comprehensive understanding highlights spiritual experiences as going beyond religion, even though religious experiences appear as part of it. These experiences can indeed be a resource contributing to experiences of hope, connectedness, meaning and coherence in life. However, they can also give rise to doubt, anxiety and feelings of loneliness and hopelessness. Rather than understanding spiritual experiences as being either ‘good’ or ‘bad’, we could approach spirituality as something that is always present in alternate and inter-related forms. Metaphorically, this could be understood as a ‘near-life experience’, summarising participants’experiences related to their struggle with issues related to suffering and health which are simultaneously present. Conclusions: If psychiatric nurses could approach this complexity and, without being judgemental, explore seemingly positive and negative experiences of spirituality as dialectically related to each other, rather than viewing them as either resources or problems, this could contribute to insiderness care and hopefully also support people who struggle with these experiences to seek help when needed

    Redefining Simulation Fidelity for Healthcare Education

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    Background. Fidelity - an intrinsic property of simulation is crucial to simulation design and to educational effectiveness. Yet the term fidelity is inconsistently used, which makes it difficult to draw inferences from current literature and translate research into practice. Aim. In this article, we attempt to bring some clarity to the term simulation fidelity in healthcare education. Method. We are opposed to the notion that high-fidelity simulation requires complete and faithful replication of reality, and instead argue for an accurate representation of real-world cues and stimuli. We address a number of issues surrounding the term fidelity and how it is currently used in the literature. Result. In recognising the limitations of current methods of describing fidelity in the literature, we propose an alternative 3-dimensional framework for fidelity along the axes of the patient, clinical scenario, and healthcare facilities as a means for more precise and practical positioning of current healthcare simulation activities. Conclusion. All aspects of fidelity significantly hinge on the learners’ perceived realism of the context of the learning episode as opposed to any one particular element such as the technology used.Peer reviewe

    A bacterial quorum-sensing precursor induces mortality in the marine coccolithophore, Emiliania huxleyi

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    © The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Microbiology 7 (2016): 59, doi:10.3389/fmicb.2016.00059.Interactions between phytoplankton and bacteria play a central role in mediating biogeochemical cycling and food web structure in the ocean. However, deciphering the chemical drivers of these interspecies interactions remains challenging. Here, we report the isolation of 2-heptyl-4-quinolone (HHQ), released by Pseudoalteromonas piscicida, a marine gamma-proteobacteria previously reported to induce phytoplankton mortality through a hitherto unknown algicidal mechanism. HHQ functions as both an antibiotic and a bacterial signaling molecule in cell–cell communication in clinical infection models. Co-culture of the bloom-forming coccolithophore, Emiliania huxleyi with both live P. piscicida and cell-free filtrates caused a significant decrease in algal growth. Investigations of the P. piscicida exometabolome revealed HHQ, at nanomolar concentrations, induced mortality in three strains of E. huxleyi. Mortality of E. huxleyi in response to HHQ occurred slowly, implying static growth rather than a singular loss event (e.g., rapid cell lysis). In contrast, the marine chlorophyte, Dunaliella tertiolecta and diatom, Phaeodactylum tricornutum were unaffected by HHQ exposures. These results suggest that HHQ mediates the type of inter-domain interactions that cause shifts in phytoplankton population dynamics. These chemically mediated interactions, and other like it, ultimately influence large-scale oceanographic processes.This research was support through funding from the Gordon and Betty Moore Foundation through Grant GBMF3301 to MJ and TM; NIH grant from the National Institute of Allergy and Infectious Disease (NIAID – 1R21Al119311-01) to TM and KW; the National Science Foundation (OCE – 1313747) and US National Institute of Environmental Health Science (P01-ES021921) through the Oceans and Human Health Program to BM. Additional financial support was provided to TM from the Flatley Discovery Lab
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