Effect of aging on the reinforcement efficiency of carbon nanotubes in epoxy matrix

The reinforcement efficiency of carbon nanotubes (CNTs) in epoxy matrix was investigated in the elastic regime. Cyclic uniaxial tensile tests were performed at constant strain amplitude and increasing maximum strain. Post-curing of the epoxy and its composite at a temperature close to the glass transition temperature allowed us to explore the effect of aging on the reinforcement efficiency of CNT. It is found that the reinforcement efficiency is compatible with a mean field mixture rule of stress reinforcement by random inclusions. It also diminishes when the maximum strain increased and this effect is amplified by aging. The decrease of elastic modulus with increasing cyclic maximum strain is quite similar to the one observed for filled elastomers with increasing strain amplitude, a phenomenon often referred as the Payne effect

HopScotch - a low-power renewable energy base station network for rural broadband access

The provision of adequate broadband access to communities in sparsely populated rural areas has in the past been severely restricted. In this paper, we present a wireless broadband access test bed running in the Scottish Highlands and Islands which is based on a relay network of low-power base stations. Base stations are powered by a combination of renewable sources creating a low cost and scalable solution suitable for community ownership. The use of the 5~GHz bands allows the network to offer large data rates and the testing of ultra high frequency ``white space'' bands allow expansive coverage whilst reducing the number of base stations or required transmission power. We argue that the reliance on renewable power and the intelligent use of frequency bands makes this approach an economic green radio technology which can address the problem of rural broadband access

Comparison of minimally invasive surgical approaches for hysterectomy at a community hospital: robotic-assisted laparoscopic hysterectomy, laparoscopic-assisted vaginal hysterectomy and laparoscopic supracervical hysterectomy

The study reported here compares outcomes of three approaches to minimally invasive hysterectomy for benign indications, namely, robotic-assisted laparoscopic (RALH), laparoscopic-assisted vaginal (LAVH) and laparoscopic supracervical (LSH) hysterectomy. The total patient cohort comprised the first 237 patients undergoing robotic surgeries at our hospital between August 2007 and June 2009; the last 100 patients undergoing LAVH by the same surgeons between July 2006 and February 2008 and 165 patients undergoing LAVHs performed by nine surgeons between January 2008 and June 2009; 87 patients undergoing LSH by the same nine surgeons between January 2008 and June 2009. Among the RALH patients were cases of greater complexity: (1) higher prevalence of prior abdominopelvic surgery than that found among LAVH patients; (2) an increased number of procedures for endometriosis and pelvic reconstruction. Uterine weights also were greater in RALH patients [207.4 vs. 149.6 (LAVH; P < 0.001) and 141.1 g (LSH; P = 0.005)]. Despite case complexity, operative time was significantly lower in RALH than in LAVH (89.9 vs. 124.8 min, P < 0.001) and similar to that in LSH (89.6 min). Estimated blood loss was greater in LAVH (167.9 ml) than in RALH (59.0 ml, P < 0.001) or LSH (65.7 ml, P < 0.001). Length of hospital stay was shorter for RALH than for LAVH or LSH. Conversion and complication rates were low and similar across procedures. Multivariable regression indicated that LAVH, obesity, uterine weight ≥250 g and older age predicted significantly longer operative time. The learning curve for RALH demonstrated improved operative time over the case series. Our findings show the benefits of RALH over LAVH. Outcomes in RALH can be as good as or better than those in LSH, suggesting the latter should be the choice primarily for women desiring cervix-sparing surgery

Holocene carbon accumulation in the peatlands of northern Scotland

The response of peatland carbon accumulation to climate can be complex, with internal feedbacks and processes that can dampen or amplify responses to external forcing. Records of carbon accumulation from peat cores provide a record of carbon which persists as peat over long periods of time, demonstrating the long-term response of peatland carbon stocks to climatic events. Numerous records of long-term carbon accumulation exist globally. However, peatlands from oceanic climates, and particularly blanket bog, remain under-represented. Scottish bogs, which collectively have more than 475 separate palaeoecological records, may prove to be a valuable resource for studying the impact of environmental change on past rates of carbon accumulation. Here we present 12 records of carbon accumulation from the north of Scotland. We support these results with a further 43 records where potential carbon accumulation is inferred from published ages. These reveal a trend of high carbon accumulation in the early Holocene, declining in the mid-to-late Holocene. The trend is consistent with accumulation profiles from other northern peatlands and is likely to have been caused by climatic cooling. Considerable variability in carbon accumulation rates between locations is apparent for the mid-to-late Holocene. We attribute to hydrologically induced changes in carbon accumulation which are likely to be inconsistent between sites

SPECULOOS exoplanet search and its prototype on TRAPPIST

One of the most significant goals of modern science is establishing whether life exists around other suns. The most direct path towards its achievement is the detection and atmospheric characterization of terrestrial exoplanets with potentially habitable surface conditions. The nearest ultracool dwarfs (UCDs), i.e. very-low-mass stars and brown dwarfs with effective temperatures lower than 2700 K, represent a unique opportunity to reach this goal within the next decade. The potential of the transit method for detecting potentially habitable Earth-sized planets around these objects is drastically increased compared to Earth-Sun analogs. Furthermore, only a terrestrial planet transiting a nearby UCD would be amenable for a thorough atmospheric characterization, including the search for possible biosignatures, with near-future facilities such as the James Webb Space Telescope. In this chapter, we first describe the physical properties of UCDs as well as the unique potential they offer for the detection of potentially habitable Earth-sized planets suitable for atmospheric characterization. Then, we present the SPECULOOS ground-based transit survey, that will search for Earth-sized planets transiting the nearest UCDs, as well as its prototype survey on the TRAPPIST telescopes. We conclude by discussing the prospects offered by the recent detection by this prototype survey of a system of seven temperate Earth-sized planets transiting a nearby UCD, TRAPPIST-1.Comment: Submitted as a chapter in the "Handbook of Exoplanets" (editors: H. Deeg & J.A. Belmonte; Section Editor: N. Narita). 16 pages, 4 figure

Attitudes and behaviors of Japanese physicians concerning withholding and withdrawal of life-sustaining treatment for end-of-life patients: results from an Internet survey

<p>Abstract</p> <p>Background</p> <p>Evidence concerning how Japanese physicians think and behave in specific clinical situations that involve withholding or withdrawal of medical interventions for end-of-life or frail elderly patients is yet insufficient.</p> <p>Methods</p> <p>To analyze decisions and actions concerning the withholding/withdrawal of life-support care by Japanese physicians, we conducted cross-sectional web-based internet survey presenting three scenarios involving an elderly comatose patient following a severe stroke. Volunteer physicians were recruited for the survey through mailing lists and medical journals. The respondents answered questions concerning attitudes and behaviors regarding decision-making for the withholding/withdrawal of life-support care, namely, the initiation/withdrawal of tube feeding and respirator attachment.</p> <p>Results</p> <p>Of the 304 responses analyzed, a majority felt that tube feeding should be initiated in these scenarios. Only 18% felt that a respirator should be attached when the patient had severe pneumonia and respiratory failure. Over half the respondents felt that tube feeding should not be withdrawn when the coma extended beyond 6 months. Only 11% responded that they actually withdrew tube feeding. Half the respondents perceived tube feeding in such a patient as a "life-sustaining treatment," whereas the other half disagreed. Physicians seeking clinical ethics consultation supported the withdrawal of tube feeding (OR, 6.4; 95% CI, 2.5–16.3; P < 0.001).</p> <p>Conclusion</p> <p>Physicians tend to harbor greater negative attitudes toward the withdrawal of life-support care than its withholding. On the other hand, they favor withholding invasive life-sustaining treatments such as the attachment of a respirator over less invasive and long-term treatments such as tube feeding. Discrepancies were demonstrated between attitudes and actual behaviors. Physicians may need systematic support for appropriate decision-making for end-of-life care.</p

Consumer perceptions of co-branding alliances: Organizational dissimilarity signals and brand fit

This study explores how consumers evaluate co-branding alliances between dissimilar partner firms. Customers are well aware that different firms are behind a co-branded product and observe the partner firms’ characteristics. Drawing on signaling theory, we assert that consumers use organizational characteristics as signals in their assessment of brand fit and for their purchasing decisions. Some organizational signals are beyond the control of the co-branding partners or at least they cannot alter them on short notice. We use a quasi-experimental design and test how co-branding partner dissimilarity affects brand fit perception. The results show that co-branding partner dissimilarity in terms of firm size, industry scope, and country-of-origin image negatively affects brand fit perception. Firm age dissimilarity does not exert significant influence. Because brand fit generally fosters a benevolent consumer attitude towards a co-branding alliance, the findings suggest that high partner dissimilarity may reduce overall co-branding alliance performance

Cost-effectiveness of a national exercise referral programme for primary care patients in Wales: results of a randomised controlled trial

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.The research was independent and funded by the Welsh Assembly Government. RTE is supported by Public Health Wales. Additional support for LM and SM during write up was provided by The Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer), a UKCRC Public Health Research: Centre of Excellence. Funding from the British Heart Foundation, Cancer Research UK, Economic and Social Research Council (RES-590-28-0005), Medical Research Council, the Welsh Assembly Government and the Wellcome Trust (WT087640MA), under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged