1,677 research outputs found

    Emergence of heat extremes attributable to anthropogenic influences

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    Climate scientists have demonstrated that a substantial fraction of the probability of numerous recent extreme events may be attributed to human-induced climate change. However, it is likely that for temperature extremes occurring over previous decades a fraction of their probability was attributable to anthropogenic influences. We identify the first record-breaking warm summers and years for which a discernible contribution can be attributed to human influence. We find a significant human contribution to the probability of record-breaking global temperature events as early as the 1930s. Since then, all the last 16 record-breaking hot years globally had an anthropogenic contribution to their probability of occurrence. Aerosol-induced cooling delays the timing of a significant human contribution to record-breaking events in some regions. Without human-induced climate change recent hot summers and years would be very unlikely to have occurred.111411Ysciescopu

    Standardisation of Target Volume Delineation for Carotid-sparing Intensity-modulated Radiotherapy in Early Glottis Cancer.

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    Aims Recently, carotid-sparing intensity-modulated radiotherapy (IMRT) for early laryngeal glottis (T1/T2N0M0) cancer has generated interest in the hope of avoiding long-term carotid toxicity, as well as concerns relating to geographical misses and long-term normal tissue toxicity. The aim of this review was to summarise the current literature on carotid-sparing IMRT for early glottis cancer, with particular focus on definitions of target volumes and the carotid arteries as organs at risk. In addition, we make suggestions for standardisation of these structures, dose constraints and dose reporting.Materials and methods From 73 references, 16 articles met the criteria for inclusion in this systematic review. These papers described two case reports, 11 planning studies and three prospective studies.Results There was variation in all target volume definitions with no clear consensus. The greatest variability was in clinical target volume definition. Carotid artery and spinal cord delineation were not always defined and most studies did not use a carotid artery constraint. Of the eight studies that reported carotid artery delineation, no two studies delineated the same length of carotid artery, yet most studies reported mean doses. Most studies used IMRT with three to seven fields. Five studies used arc therapy and two studies used tomotherapy.Conclusion This review highlights a lack of consensus in target volume definitions in carotid-sparing IMRT. Ultimately, long-term prospective data are required to show the benefit of carotid-sparing IMRT. Pooled data will prove useful as most studies will report on small numbers of patients. Therefore, adopting a consensus now on target volume definition, dose constraints and dose reporting will be crucial

    Preparation, structural characterisation and antibacterial properties of Ga-doped sol-gel phosphate-based glass

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    A sol-gel preparation of Ga-doped phosphate-based glass with potential application in antimicrobial devices has been developed. Samples of composition (CaO)(0.30)(Na2O)(0.20-x) (Ga2O3) (x) (P2O5)(0.50) where x = 0 and 0.03 were prepared, and the structure and properties of the gallium-doped sample compared with those of the sample containing no gallium. Analysis of the P-31 MAS NMR data demonstrated that addition of gallium to the sol-gel reaction increases the connectivity of the phosphate network at the expense of hydroxyl groups. This premise is supported by the results of the elemental analysis, which showed that the gallium-free sample contains significantly more hydrogen and by FTIR spectroscopy, which revealed a higher concentration of -OH groups in that sample. Ga K-edge extended X-ray absorption fine structure and X-ray absorption near-edge structure data revealed that the gallium ions are coordinated by six oxygen atoms. In agreement with the X-ray absorption data, the high-energy XRD results also suggest that the Ga3+ ions are octahedrally coordinated with respect to oxygen. Antimicrobial studies demonstrated that the sample containing Ga3+ ions had significant activity against Staphylococcus aureus compared to the control

    Plaque Neovascularization Is Increased in Human Carotid Atherosclerosis Related to Prior Neck Radiotherapy A Contrast-Enhanced Ultrasound Study

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    OBJECTIVES The aim of this study was to determine the effect of radiotherapy (RT) on intraplaque neovascularization (IPN) in human carotid arteries. BACKGROUND Exposure of the carotid arteries to RT during treatment for head and neck cancer is associated with increased risk for stroke. However, the effect of RT on IPN, a precursor to intraplaque hemorrhage and thus associated with plaque vulnerability, is unknown. METHODS In this cross-sectional study, patients who had undergone unilateral RT for head and neck cancer >= 2 years previously underwent B-mode and contrast-enhanced ultrasound of both RT-side and non-RT-side carotid arteries. Presence of IPN during contrast-enhanced ultrasound was judged semiquantitatively as grade 0 (absent), grade 1 (present but limited to plaque base), or grade 2 (extensive and noted within plaque body). RESULTS Of 49 patients studied, 38 (78%) had plaques. The number of plaques was significantly greater in the RT than the non-RT arteries. Overall, 48 of 64 RT-side plaques (75%) had IPN compared with 9 of 23 non-RT-side (39%) plaques (p = 0.002). Among patients with plaques, IPN was present in 81% of patients with RT-side plaques and 41% of patients with non-RT-side plaques (p = 0.004). Grade 0 IPN was significantly more common in patients with non-RT-side plaques (25% vs. 61%; p = 0.002), whereas grade 2 plaques were more common on the RT side (31% vs. 9%; p = 0.03). The only clinical variable that predicted the presence or absence of IPN was RT laterality. CONCLUSIONS This is the first study in humans to reveal a significant association between RT and the presence and extent of IPN. This may provide insights into the mechanisms underlying the increased stroke risk among survivors of head and neck cancer treated by RT. (C) 2016 by the American College of Cardiology Foundation

    Diel turbidity cycles in a headwater stream: evidence of nocturnal bioturbation?

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    Purpose: A small number of recent studies have linked daily cycles in stream turbidity to nocturnal bioturbation by aquatic fauna, principally crayfish, and demonstrated this process can significantly impact upon water quality under baseflow conditions. Adding to this limited body of research, we use high-resolution water quality monitoring data to investigate evidence of diel turbidity cycles in a lowland, headwater stream with a known signal crayfish (Pacifastacus leniusculus) population and explore a range of potential causal mechanisms. Materials and methods: Automatic bankside monitoring stations measured turbidity and other water quality parameters at 30-min resolution at three locations on the River Blackwater, Norfolk, UK during 2013. Specifically, we focused on two 20-day periods of baseflow conditions during January and April 2013 which displayed turbidity trends typical of winter and spring seasons, respectively. The turbidity time-series, which were smoothed with 6.5 hour Savitzky-Golay filters to highlight diel trends, were correlated against temperature, stage, dissolved oxygen and pH to assess the importance of abiotic influences on turbidity. Turbidity was also calibrated against suspended particulate matter (SPM) over a wide range of values via linear regression. Results and discussion: Pronounced diel turbidity cycles were found at two of the three sites under baseflow conditions during April. Spring night-time turbidity values consistently peaked between 21:00 and 04:00 with values increasing by ~10 nephelometric turbidity units (NTU) compared with the lowest recorded daytime values which occurred between 10:00 and 14:00. This translated into statistically significant increases in median midnight SPM concentration of up to 76% compared with midday, with night-time (18:00 – 05:30) SPM loads also up to 30% higher than that recorded during the daytime (06:00 – 17:30). Relating turbidity to other water quality parameters exhibiting diel cycles revealed there to be neither any correlation that might indicate a causal link, nor any obvious mechanistic connections to explain the temporal turbidity trends. Diel turbidity cycles were less prominent at all sites during the winter. Conclusions: Considering the seasonality and timing of elevated turbidity, visual observations of crayfish activity, and an absence of mechanistic connections with other water quality parameters, the results presented here are consistent with the hypothesis that nocturnal bioturbation is responsible for generating diel turbidity cycles under baseflow conditions in headwater streams. However, further research in a variety of fluvial environments is required to better assess the spatial extent, importance and causal mechanisms of this phenomenon

    Do traditional risk stratification models for cerebrovascular events apply in irradiated head and neck cancer patients?

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    Background Primary radical radiotherapy (RT) for head and neck cancer (HNC) often results in significant radiation dose to the carotid arteries.Aim We assessed whether HNC patients are at increased risk of a cerebrovascular event primarily due to RT or other risk factors for atherosclerosis by (i) risk-stratifying patients according to validated QRISK-2 and QSTROKE scores and (ii) comparing the prevalence of carotid artery stenosis (CAS) in irradiated and unirradiated carotid arteries.Design HNC patients treated with an RT dose >50 Gy to one side of the neck ≥2 years previously were included.Methods QRISK-2 (2014) and Q-STROKE (2014) scores were calculated. We compared the prevalence of CAS in segments of the common carotid artery on the irradiated and unirradiated sides of the neck.Results Fifty patients (median age of 58 years (interquartile range (IQR) 50-62)) were included. The median QRISK-2 score was 10% (IQR 4.4-15%) and the median QSTROKE score was 3.4% (IQR 1.4-5.3%). For both scores, no patient was classified as high risk. Thirty-eight patients (76%) had CAS in one or both arteries. There was a significant difference in the number of irradiated arteries with stenosis (N = 37) compared with unirradiated arteries (N = 16) (P < 0.0001). There were more plaques on the irradiated artery compared with the unirradiated side - 64/87 (73.6%) versus 23/87 (26.4%), respectively (P < 0.001). Conclusions Traditional vascular risk factors do not play a role in radiation-induced carotid atherosclerosis. Clinicians should be aware that traditional risk prediction models may under-estimate stroke risk in these patients

    Capture the fracture: a best practice framework and global campaign to break the fragility fracture cycle

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    Summary The International Osteoporosis Foundation (IOF) Capture the Fracture Campaign aims to support implementation of Fracture Liaison Services (FLS) throughout the world. Introduction FLS have been shown to close the ubiquitous secondary fracture prevention care gap, ensuring that fragility fracture sufferers receive appropriate assessment and intervention to reduce future fracture risk. Methods Capture the Fracture has developed internationally endorsed standards for best practice, will facilitate change at the national level to drive adoption of FLS and increase awareness of the challenges and opportunities presented by secondary fracture prevention to key stakeholders. The Best Practice Framework (BPF) sets an international benchmark for FLS, which defines essential and aspirational elements of service delivery. Results The BPF has been reviewed by leading experts from many countries and subject to beta-testing to ensure that it is internationally relevant and fit-for-purpose. The BPF will also serve as a measurement tool for IOF to award ‘Capture the Fracture Best Practice Recognition’ to celebrate successful FLS worldwide and drive service development in areas of unmet need. The Capture the Fracture website will provide a suite of resources related to FLS and secondary fracture prevention, which will be updated as new materials become available. A mentoring programme will enable those in the early stages of development of FLS to learn from colleagues elsewhere that have achieved Best Practice Recognition. A grant programme is in development to aid clinical systems which require financial assistance to establish FLS in their localities. Conclusion Nearly half a billion people will reach retirement age during the next 20 years. IOF has developed Capture the Fracture because this is the single most important thing that can be done to directly improve patient care, of both women and men, and reduce the spiralling fracture-related care costs worldwide.</p

    Cardiorespiratory fitness is associated with hard and light intensity physical activity but not time spent sedentary in 10–14 year old schoolchildren: the HAPPY study

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    Sedentary behaviour is a major risk factor for developing chronic diseases and is associated with low cardiorespiratory fitness in adults. It remains unclear how sedentary behaviour and different physical activity subcomponents are related to cardiorespiratory fitness in children. The purpose of this study was to assess how sedentary behaviour and different physical activity subcomponents are associated with 10–14 year-old schoolchildren's cardiorespiratory fitness

    Current Practice in Vitamin D Management in Allogeneic Hematopoietic Stem Cell Transplantation: A Survey by the Transplant Complications Working Party of the European Society for Blood and Marrow Transplantation

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    Beyond its impact on bone health, numerous studies have investigated the immune-regulatory properties of vitamin D and shown how its deficiency can affect outcomes in allogeneic hematopoietic stem cell transplantation (HSCT), particularly in acute or chronic graft-versus-host disease. This survey, carried out by the Transplant Complications Working Party of the European Society for Blood and Marrow Transplantation (EBMT), describes the current clinical practice discrepancies across the EBMT HSCT programs. We therefore recommend the development of evidence-based guidelines to standardize evaluation criteria and to harmonize the management of vitamin D deficiency in patients undergoing allogeneic HSCT

    Planetary Dynamics and Habitable Planet Formation In Binary Star Systems

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    Whether binaries can harbor potentially habitable planets depends on several factors including the physical properties and the orbital characteristics of the binary system. While the former determines the location of the habitable zone (HZ), the latter affects the dynamics of the material from which terrestrial planets are formed (i.e., planetesimals and planetary embryos), and drives the final architecture of the planets assembly. In order for a habitable planet to form in a binary star system, these two factors have to work in harmony. That is, the orbital dynamics of the two stars and their interactions with the planet-forming material have to allow terrestrial planet formation in the habitable zone, and ensure that the orbit of a potentially habitable planet will be stable for long times. We have organized this chapter with the same order in mind. We begin by presenting a general discussion on the motion of planets in binary stars and their stability. We then discuss the stability of terrestrial planets, and the formation of potentially habitable planets in a binary-planetary system.Comment: 56 pages, 29 figures, chapter to appear in the book: Planets in Binary Star Systems (Ed. N. Haghighipour, Springer publishing company
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