709 research outputs found

    Fibre laser hydrophones for cosmic ray particle detection

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    The detection of ultra high energetic cosmic neutrinos provides a unique means to search for extragalactic sources that accelerate particles to extreme energies. It allows to study the neutrino component of the GZK cut-off in the cosmic ray energy spectrum and the search for neutrinos beyond this limit. Due to low expected flux and small interaction cross-section of neutrinos with matter large experimental set-ups are needed to conduct this type of research. Acoustic detection of cosmic rays may provide a means for the detection of ultra-high energetic neutrinos. Using relative low absorption of sound in water, large experimental set-ups in the deep sea are possible that are able to detect these most rare events, but it requires highly sensitive hydrophones as the thermo-acoustic pulse originating from a particle shower in water has a typical amplitude as low as a mPa. It has been shown in characterisation measurements that the fibre optic hydrophone technology as designed and realised at TNO provides the required sensitivity. Noise measurements and pulse reconstruction have been conducted that show that the hydrophone is suited as a particle detector.Comment: Submitted to the proceedings of "13th Topical Seminar on Innovative Particle and Radiation Detectors (IPRD13)

    Successful Thrombectomy via a Surgically Reopened Umbilical Vein for Extended Portal Vein Thrombosis Caused by Portal Vein Embolization prior to Extended Liver Resection

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    Selective portal vein embolization (PVE) before extended liver surgery is an accepted method to stimulate growth of the future liver remnant. Portal vein thrombosis (PVT) of the main stem and the non-targeted branches to the future liver remnant is a rare but major complication of PVE, requiring immediate revascularization. Without revascularization, curative liver surgery is not possible, resulting in a potentially life-threatening situation. We here present a new surgical technique to revascularize the portal vein after PVT by combining a surgical thrombectomy with catheter-based thrombolysis via the surgically reopened umbilical vein. This technique was successfully applied in a patient who developed thrombosis of the portal vein main stem, as well as the left portal vein and its branches to the left lateral segments after selective right-sided PVE in preparation for an extended right hemihepatectomy. The advantage of this technique is the avoidance of an exploration of hepatoduodenal ligament and a venotomy of the portal vein. The minimal surgical trauma facilitates additional intravascular thrombolytic therapy as well as the future right extended hemihepatectomy. We recommend this technique in patients with extensive PVT in which percutaneous less invasive therapies have been proven unsuccessful

    Multi-layer coating development for XEUS

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    Graded depth multi-layer coatings have the potential to optimise the performance of X-ray reflective surfaces for improved energy response. A study of deposition techniques on silicon substrates representative of the XEUS High Performance Pore Optics (HPO) technology has been carried out. Measurements at synchrotron radiation facilities have been used to confirm the excellent performance improvements achievable with Mo/Si and W/Si multilayers. Future activities that will be necessary to implement such coatings in the HPO assembly sequence are highlighted. Further coating developments that may allow an optimisation of the XEUS effective area in light of potential changes to science requirements and telescope configurations are also identified. Finally an initial measurement of effects of radiation damage within the multilayers is reported

    Actual postoperative protein and calorie intake in patients undergoing major open abdominal cancer surgery:A prospective, observational cohort study

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    Background Adequate nutritional protein and energy intake are required for optimal postoperative recovery. There are limited studies reporting the actual postoperative protein and energy intake within the first week after major abdominal cancer surgery. The main objective of this study was to quantify the protein and energy intake after major abdominal cancer surgery. Methods We conducted a prospective cohort study. Nutrition intake was assessed with a nutrition diary. The amount of protein and energy consumed through oral, enteral, and parenteral nutrition was recorded and calculated separately. Based on the recommendations of the European Society for Clinical Nutrition and Metabolism (ESPEN), protein and energy intake were considered insufficient when patients received Fifty patients were enrolled in this study. Mean daily protein and energy intake was 0.61 +/- 0.44 g/kg/day and 9.58 +/- 3.33 kcal/kg/day within the first postoperative week, respectively. Protein and energy intake were insufficient in 45 [90%] and 41 [82%] of the 50 patients, respectively. Patients with Clavien-Dindo grade >= III complications consumed less daily protein compared with the group of patients without complications and patients with grade I or II complications. Conclusion During the first week after major abdominal cancer surgery, the majority of patients do not consume an adequate amount of protein and energy. Incorporating a registered dietitian into postoperative care and adequate nutrition support after major abdominal cancer surgery should be a standard therapeutic goal to improve nutrition intake

    Evaluating Active U: an Internet-mediated physical activity program.

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    Background: Engaging in regular physical activity can be challenging, particularly during the winter months. To promote physical activity at the University of Michigan during the winter months, an eight-week Internet-mediated program (Active U) was developed providing participants with an online physical activity log, goal setting, motivational emails, and optional team participation and competition. Methods: This study is a program evaluation of Active U. Approximately 47,000 faculty, staff, and graduate students were invited to participate in the online Active U intervention in the winter of 2007. Participants were assigned a physical activity goal and were asked to record each physical activity episode into the activity log for eight weeks. Statistics for program reach, effectiveness, adoption, and implementation were calculated using the Re-Aim framework. Multilevel regression analyses were used to assess the decline in rates of data entry and goal attainment during the program, to assess the likelihood of joining a team by demographic characteristics, to test the association between various predictors and the number of weeks an individual met his or her goal, and to analyze server load. Results: Overall, 7,483 individuals registered with the Active U website (≈16% of eligible), and 79% participated in the program by logging valid data at least once. Staff members, older participants, and those with a BMI < 25 were more likely to meet their weekly physical activity goals, and average rate of meeting goals was higher among participants who joined a competitive team compared to those who participated individually (IRR = 1.28, P < .001). Conclusion: Internet-mediated physical activity interventions that focus on physical activity logging and goal setting while incorporating team competition may help a significant percentage of the target population maintain their physical activity during the winter months

    Social Disparities in Private Renting Amongst Young Families in England and Wales, 2001-2011

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    This is the final version of the article. It first appeared from Taylor & Francis via https://doi.org/10.1080/14036096.2016.1242511In Britain, the proportion of young families living in the private rented sector (PRS) has risen sharply in recent years. There is mounting concern that this trend could be particularly pronounced amongst less advantaged young families, who may be disproportionately channelled into relatively costly, insecure and lower quality accommodation in the PRS by growing difficulties accessing other tenures. In consequence, this paper uses the Office for National Statistics Longitudinal Study of England and Wales to compare how family structure and socio-economic characteristics shaped rates of private renting amongst young adults heading families in 2001 and 2011. The results show that social disparities generally increased during this period as private renting expanded most rapidly amongst some types of lone parent and amongst young adults heading couple families with a less advantaged class position. Increasing housing inequalities between young people may thus be as much a feature of “Generation Rent” as deepening divides between generations.This work was supported by an Economic and Social Research Council (ESRC) Future Research Leaders award [grant number ES/L009498/1]. Additional financial support was provided by the Isaac Newton Trust

    Are academics willing to forgo citations to publish in high-status journals? Examining preferences for 4* and 4-rated journal publication among UK business and management academics

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    Academics often judge themselves and are judged by others according to the status of the journals in which they publish. Little is known about whether individual scholars would choose to publish an article in a high-status journal if it would garner similar or lower levels of scholarly impact than an article published in a lower-status journal. Drawing upon status theory, we explore whether and how much business school academics are willing to ‘pay’, as captured by a hypothetical level of ‘forfeited’ citations, to publish in high-status 4* journals rather than leading specialized 4-rated journals. Using choice-set design and survey data from UK business and management scholars, we suggest and empirically demonstrate that the willingness to forgo citations to publish in 4* journals is strongest among academics who have already published in 4* and/or 4-rated journals. Contrary to our expectations, we find that an individual’s existing scholarly impact, as captured by prior citations, has no effect on this preference. We also show that academics working in high-ranked institutions would give up more citations for 4* journal publication than those working at lower-ranked institutions. We explore the implications of these findings for theories of academic status, journal rankings and research assessment systems

    Pretransplant sequential hypo- and normothermic machine perfusion of suboptimal livers donated after circulatory death using a hemoglobin-based oxygen carrier perfusion solution

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    Ex situ dual hypothermic oxygenated machine perfusion (DHOPE) and normothermic machine perfusion (NMP) of donor livers may have a complementary effect when applied sequentially. While DHOPE resuscitates the mitochondria and increases hepatic adenosine triphosphate (ATP) content, NMP enables hepatobiliary viability assessment prior to transplantation. In contrast to DHOPE, NMP requires a perfusion solution with an oxygen carrier, for which red blood cells (RBC) have been used in most series. RBC, however, have limitations and cannot be used cold. We, therefore, established a protocol of sequential DHOPE, controlled oxygenated rewarming (COR), and NMP using a new hemoglobin-based oxygen carrier (HBOC)-based perfusion fluid (DHOPE-COR-NMP trial, NTR5972). Seven livers from donation after circulatory death (DCD) donors, which were initially declined for transplantation nationwide, underwent DHOPE-COR-NMP. Livers were considered transplantable if perfusate pH and lactate normalized, bile production was >= 10 mL and biliary pH > 7.45 within 150 minutes of NMP. Based on these criteria five livers were transplanted. The primary endpoint, 3-month graft survival, was a 100%. In conclusion, sequential DHOPE-COR-NMP using an HBOC-based perfusion fluid offers a novel method of liver machine perfusion for combined resuscitation and viability testing of suboptimal livers prior to transplantation

    Standalone vertex nding in the ATLAS muon spectrometer

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    A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011
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