385 research outputs found

    Simple Opportunistic Encryption

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    Network traffic encryption is becoming a requirement, not an option. Enabling encryption will be a communal effort so a solution that gives partial benefits until fully deployed is needed. A solution that requires little changes to existing infrastructure will also help as it can be quickly deployed to give immediate shortterm benefits. We argue that tcpcrypt, a TCP option for opportunistic encryption is the path of least-resistance for a solution against large-scale traffic encryption. Tcpcrypt requires no changes to applications, is compatible with existing networks (works with NATs), and just works by default. It is high performance, so it can be deployed on servers without much concern. tcpcrypt attempts to maximize security for any given setting. By default, it will protect against passive eavesdropping, and also allows detecting large scale interception. With authentication, tcpcrypt can provide full security against active attackers and so it is a complete solution both for the short-term and long-term

    Delay is Not an Option: Low Latency Routing in Space

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    SpaceX has filed plans with the US Federal Communications Committee (FCC) to build a constellation of 4,425 low Earth orbit communication satellites. It will use phased array antennas for up and downlinks and laser communication between satellites to provide global low-latency high bandwidth coverage. To understand the latency propertes of such a network, we built a simulator based on public details from the FCC filings. We evaluate how to use the laser links to provide a network, and look at the problem of routing on this network. We provide a preliminary evaluation of how well such a network can provide low-latency communications, and examine its multipath properties. We conclude that a network built in this manner can provide lower latency communications than any possible terrestrial optical fiber network for communications over distances greater than about 3000 km

    SUPPORT FOR COLLABORATIVE AUTHORING VIA EMAIL - THE MESSIE ENVIRONMENT

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    MESSIE is a collaborative authoring environment to support the production of large-scale documents by teams of geographically distributed groups of authors working with hetereogenous systems. The environment allows authors to submit text at various stages of gestation (e.g. list of topics, first draft) to a shared filestore via email. All authors collaborating on a document can read each others’ contributions, and add suggestions, comments and additional material directly to the document. The system integrates automatically answered electronic mail, shared file store administration, and a version control tool in a UNIX environment. The paper describes design and implementation strategy, and reports observations and a number of changes which were made during a 4-month trial period with three collaborative authoring teams

    The heart healthy lenoir project-an intervention to reduce disparities in hypertension control: study protocol

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    Background Racial disparities in blood pressure control are well established; however the impact of low health literacy (LHL) on blood pressure has garnered less attention. Office based interventions that are created with iterative patient, practice and community stakeholder input and are rolled out incrementally, may help address these disparities in hypertension control. This paper describes our study protocol. Methods/design Using a community based participatory research (CBPR) approach, we designed and implemented a cohort study that includes both a practice level and patient level intervention to enhance the care and support of patients with hypertension in primary care practices in a rural region of eastern North Carolina. The study is divided into a formative phase and an ongoing 2.5 year implementation phase. Our main care enhancement activities include the integration of a community health coach, using home blood pressure monitoring in clinical decision making, standardizing care delivery processes, and working to improve medication adherence. Main outcomes include overall blood pressure change, the differential change in blood pressure by race (African American vs. White) and health literacy level (low vs. higher health literacy). Discussion Using a community based participatory approach in primary care practice settings has helped to engage patients and practice staff and providers in the research effort and in making practice changes to support hypertension care. Practices have engaged at varying levels, but progress has been made in implementing and iteratively improving upon the interventions to date

    Immediate thoracotomy for penetrating injuries: Ten years' experience at a Dutch level I trauma center

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    Background: An emergency department thoracotomy (EDT) or an emergency thoracotomy (ET) in the operating theater are both beneficial in selected patients following thoracic penetrating injuries. Since outcome-descriptive European studies are lacking, the aim of this retrospective study was to evaluate ten years of experience at a Dutch level I trauma center. Method: Data on patients who underwent an immediate thoracotomy after sustaining a penetrating thoracic injury between October 2000 and January 2011 were collected from the trauma registry and hospital files. Descriptive and univariate analyses were performed. Results: Among 56 patients, 12 underwent an EDT and 44 an ET. Forty-six patients sustained one or multiple stab wounds, versus ten with one or multiple gunshot wounds. Patients who had undergone an EDT had a lower GCS (p < 0. 001), lower pre-hospital RTS and hospital triage RTS (p < 0. 001 and p = 0. 009, respectively), and a lower SBP (p = 0. 038). A witnessed loss of signs of life generally occurred in EDT patients and was accompanied by 100 % mortality. Survival following EDT was 25 %, which was significantly lower than in the ET group (75 %; p = 0. 002). Survivors had lower ISS (p = 0. 011), lower rates of pre-hospital (p = 0. 031) and hospital (p = 0. 003) hemodynamic instability, and a lower prevalence of concomitant abdominal injury (p = 0. 002). Conclusion: The overall survival rate in our study was 64 %. The outcome of immediate thoracotomy performed in this level I trauma center was similar to those obtained in high-incidence regions like the US and South Africa. This suggests that trauma units where immediate thoracotomies are not part of the daily routine can achieve similar results, if properly trained

    Buprenorphine-Naloxone in the Treatment of Codeine Dependence: a Scoping Review of Clinical Case Presentations

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    Misuse of prescribed and over the counter (OTC) codeine containing medicines is an increasing public health concern in recent times. Studies have called for low threshold treatment services for individuals experiencing codeine dependence using buprenorphine naloxone therapy. We present a scoping review of clinical case presentation literature on the use of buprenorphine-naloxone in the treatment of codeine dependence. Seven records (four single case studies and three case series) on codeine dependence treated with buprenorphine-naloxone were included. Five themes emerged following a review of the cases for the treatment of codeine dependence with buprenorphine-naloxone. They are: (1) Patient Profiles; (2) History of Codeine Misuse; (3) Medical Problems; (4) Use of Other Substances; and (5) Buprenorphine-naloxone in the treatment of Codeine Dependence. The review highlights the complexities of patients with regards to pain, psychiatric illness, poly substance use and iatrogenic dependence, with findings encouraging in terms of patient stabilisation and recovery

    The RESPITE trial: remifentanil intravenously administered patient-controlled analgesia (PCA) versus pethidine intramuscular injection for pain relief in labour: study protocol for a randomised controlled trial

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    Background The commonest opioid used for pain relief in labour is pethidine (meperidine); however, its effectiveness has long been challenged and the drug has known side effects including maternal sedation, nausea and potential transfer across the placenta to the foetus. Over a third of women receiving pethidine require an epidural due to inadequate pain relief. Epidural analgesia increases the risk of an instrumental vaginal delivery and its associated effects. Therefore, there is a clear need for a safe, effective, alternative analgesic to pethidine. Evidence suggests that remifentanil patient-controlled analgesia (PCA) reduces epidural conversion rates compared to pethidine; however, no trial has yet investigated this as a primary endpoint. We are, therefore, comparing pethidine intramuscular injection to remifentanil PCA in a randomised controlled trial. Methods/design Women in established labour, requesting systemic opioid pain relief, will be randomised to either intravenously administered remifentanil PCA (intervention) or pethidine intramuscular injection (control) in an unblinded, 1:1 individual randomised trial. Following informed consent, 400 women in established labour, who request systemic opioid pain relief, from NHS Trusts across England will undergo a minimised randomisation by a computer or automated telephone system to either pethidine or remifentanil. In order to balance the groups this minimisation is based on four parameters; parity (nulliparous versus multiparous), maternal age (<20, 20 < 30, 30 < 40, 40+ years), ethnicity (South Asian (Pakistani/Indian/Bangladeshi) versus Other) and induced versus spontaneous labour. The effectiveness of pain relief provided by each technique will be recorded every 30 min after time zero, until epidural placement, delivery or transfer to theatre, quantified by Visual Analogue Scale. Incidence of maternal side effects including sedation, delivery mode, foetal distress requiring delivery, neonatal status at delivery and rate of initiation of breastfeeding within the first hour of birth will also be recorded. Maternal satisfaction with her childbirth experience will be determined by a postpartum questionnaire prior to discharge from the delivery ward. Discussion The RESPITE trial’s primary outcome is the proportion of women who have an epidural placed for pain relief in labour in each arm. Trial Registration Current Controlled Trials registration number: ISRCTN29654603. Registered on 23 July 2013

    Convergent evolution of chicken Z and human X chromosomes by expansion and gene acquisition

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    In birds, as in mammals, one pair of chromosomes differs between the sexes. In birds, males are ZZ and females ZW. In mammals, males are XY and females XX. Like the mammalian XY pair, the avian ZW pair is believed to have evolved from autosomes, with most change occurring in the chromosomes found in only one sex—the W and Y chromosomes1, 2, 3, 4, 5. By contrast, the sex chromosomes found in both sexes—the Z and X chromosomes—are assumed to have diverged little from their autosomal progenitors2. Here we report findings that challenge this assumption for both the chicken Z chromosome and the human X chromosome. The chicken Z chromosome, which we sequenced essentially to completion, is less gene-dense than chicken autosomes but contains a massive tandem array containing hundreds of duplicated genes expressed in testes. A comprehensive comparison of the chicken Z chromosome with the finished sequence of the human X chromosome demonstrates that each evolved independently from different portions of the ancestral genome. Despite this independence, the chicken Z and human X chromosomes share features that distinguish them from autosomes: the acquisition and amplification of testis-expressed genes, and a low gene density resulting from an expansion of intergenic regions. These features were not present on the autosomes from which the Z and X chromosomes originated but were instead acquired during the evolution of Z and X as sex chromosomes. We conclude that the avian Z and mammalian X chromosomes followed convergent evolutionary trajectories, despite their evolving with opposite (female versus male) systems of heterogamety. More broadly, in birds and mammals, sex chromosome evolution involved not only gene loss in sex-specific chromosomes, but also marked expansion and gene acquisition in sex chromosomes common to males and females.National Science Foundation (U.S.)Howard Hughes Medical Institut

    Assessing the impact of the threatened crucian carp (Carassius carassius) on pond invertebrate diversity: A comparison of conventional and molecular tools

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    Fishes stocked for recreation and angling can damage freshwater habitats and negatively impact biodiversity. The pond-associated crucian carp (Carassius carassius) is rare across Europe and is stocked for conservation management in England, but its impacts on pond biota are understudied. Freshwater invertebrates contribute substantially to aquatic biodiversity, encompassing many rare and endemic species, but their small size and high abundance complicate their assessment. Practitioners have employed sweep-netting and kick-sampling with microscopy (morphotaxonomy), but specimen size/quality and experience can bias identification. DNA and environmental DNA (eDNA) metabarcoding offer alternative means of invertebrate assessment. We compared invertebrate diversity in ponds (N = 18) with and without crucian carp using morphotaxonomic identification, DNA metabarcoding and eDNA metabarcoding. Five 2 L water samples and 3 min sweep-net samples were collected at each pond. Inventories produced by morphotaxonomic identification of netted samples, DNA metabarcoding of bulk tissue samples and eDNA metabarcoding of water samples were compared. Alpha diversity was greatest with DNA or eDNA metabarcoding, depending on whether standard or unbiased methods were considered. DNA metabarcoding reflected morphotaxonomic identification, whereas eDNA metabarcoding produced markedly different communities. These complementary tools should be combined for comprehensive invertebrate assessment. Crucian carp presence minimally reduced alpha diversity in ponds, but positively influenced beta diversity through taxon turnover (i.e., ponds with crucian carp contained different invertebrates to fishless ponds). Crucian carp presence contributes to landscape-scale invertebrate diversity, supporting continued conservation management in England. Our results show that molecular tools can enhance freshwater invertebrate assessment and facilitate development of more accurate and ecologically effective pond management strategies
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