1,464 research outputs found

    Fractional Cauchy problems on bounded domains: survey of recent results

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    In a fractional Cauchy problem, the usual first order time derivative is replaced by a fractional derivative. This problem was first considered by \citet{nigmatullin}, and \citet{zaslavsky} in Rd\mathbb R^d for modeling some physical phenomena. The fractional derivative models time delays in a diffusion process. We will give a survey of the recent results on the fractional Cauchy problem and its generalizations on bounded domains D\subset \rd obtained in \citet{m-n-v-aop, mnv-2}. We also study the solutions of fractional Cauchy problem where the first time derivative is replaced with an infinite sum of fractional derivatives. We point out a connection to eigenvalue problems for the fractional time operators considered. The solutions to the eigenvalue problems are expressed by Mittag-Leffler functions and its generalized versions. The stochastic solution of the eigenvalue problems for the fractional derivatives are given by inverse subordinators

    Pathways for outpatient management of venous thromboembolism in a UK centre.

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    It has become widely recognised that outpatient treatment may be suitable for many patients with venous thromboembolism. In addition, non-vitamin K antagonist oral anticoagulants that have been approved over the last few years have the potential to be an integral component of the outpatient care pathway, owing to their oral route of administration, lack of requirement for routine anticoagulation monitoring and simple dosing regimens. A robust pathway for outpatient care is also vital; one such pathway has been developed at Sheffield Teaching Hospitals in the UK. This paper describes the pathway and the arguments in its favour as an example of best practice and value offered to patients with venous thromboembolism. The pathway has two branches (one for deep vein thrombosis and one for pulmonary embolism), each with the same five-step process for outpatient treatment. Both begin from the point that the patient presents (in the Emergency Department, Thrombosis Clinic or general practitioner's office), followed by diagnosis, risk stratification, treatment choice and, finally, follow-up. The advantages of these pathways are that they offer clear, evidence-based guidance for the identification, diagnosis and treatment of patients who can safely be treated in the outpatient setting, and provide a detailed, stepwise process that can be easily adapted to suit the needs of other institutions. The approach is likely to result in both healthcare and economic benefits, including increased patient satisfaction and shorter hospital stays

    Projections of the current and future disease burden of hepatitis C virus infection in Malaysia

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    The prevalence of hepatitis C virus (HCV) infection in Malaysia has been estimated at 2.5% of the adult population. Our objective, satisfying one of the directives of the WHO Framework for Global Action on Viral Hepatitis, was to forecast the HCV disease burden in Malaysia using modelling methods.An age-structured multi-state Markov model was developed to simulate the natural history of HCV infection. We tested three historical incidence scenarios that would give rise to the estimated prevalence in 2009, and calculated the incidence of cirrhosis, end-stage liver disease, and death, and disability-adjusted life-years (DALYs) under each scenario, to the year 2039. In the baseline scenario, current antiviral treatment levels were extended from 2014 to the end of the simulation period. To estimate the disease burden averted under current sustained virological response rates and treatment levels, the baseline scenario was compared to a counterfactual scenario in which no past or future treatment is assumed.In the baseline scenario, the projected disease burden for the year 2039 is 94,900 DALYs/year (95% credible interval (CrI): 77,100 to 124,500), with 2,002 (95% CrI: 1340 to 3040) and 540 (95% CrI: 251 to 1,030) individuals predicted to develop decompensated cirrhosis and hepatocellular carcinoma, respectively, in that year. Although current treatment practice is estimated to avert a cumulative total of 2,200 deaths from DC or HCC, a cumulative total of 63,900 HCV-related deaths is projected by 2039.The HCV-related disease burden is already high and is forecast to rise steeply over the coming decades under current levels of antiviral treatment. Increased governmental resources to improve HCV screening and treatment rates and to reduce transmission are essential to address the high projected HCV disease burden in Malaysia

    Puzzles of Dark Matter - More Light on Dark Atoms?

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    Positive results of dark matter searches in experiments DAMA/NaI and DAMA/LIBRA confronted with results of other groups can imply nontrivial particle physics solutions for cosmological dark matter. Stable particles with charge -2, bound with primordial helium in O-helium "atoms" (OHe), represent a specific nuclear-interacting form of dark matter. Slowed down in the terrestrial matter, OHe is elusive for direct methods of underground Dark matter detection using its nuclear recoil. However, low energy binding of OHe with sodium nuclei can lead to annual variations of energy release from OHe radiative capture in the interval of energy 2-4 keV in DAMA/NaI and DAMA/LIBRA experiments. At nuclear parameters, reproducing DAMA results, the energy release predicted for detectors with chemical content other than NaI differ in the most cases from the one in DAMA detector. Moreover there is no bound systems of OHe with light and heavy nuclei, so that there is no radiative capture of OHe in detectors with xenon or helium content. Due to dipole Coulomb barrier, transitions to more energetic levels of Na+OHe system with much higher energy release are suppressed in the correspondence with the results of DAMA experiments. The proposed explanation inevitably leads to prediction of abundance of anomalous Na, corresponding to the signal, observed by DAMA.Comment: Contribution to Proceedings of XIII Bled Workshop "What Comes beyond the Standard Model?

    Concordance of health states in couples: Analysis of self-reported, nurse administered and blood-based biomarker data in the UK Understanding Society panel

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    We use self-reported health measures, nurse-administered measurements and blood-based biomarkers to examine the concordance between health states of partners in marital/cohabiting relationships in the UK. A model of cumulative health exposures is used to interpret the empirical pattern of betweenpartner health correlation in relation to elapsed relationship duration, allowing us to distinguish non-causal correlation due to assortative mating from potentially causal effects of shared lifestyle and environmental factors. We find important differences between the results for different health indicators, with strongest homogamy correlations observed for adiposity, followed by blood pressure, heart rate, inflammatory markers and cholesterol, and also self-assessed general health and functional difficulties. We find no evidence of a “dose-response relationship” for marriage duration, and show that this suggests – perhaps counterintuitively – that shared lifestyle factors and homogamous partner selection make roughly equal contributions to the concordance we observe in most of the health measures we examine

    Achieved systolic blood pressure in older people: A systematic review and meta-analysis

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    Background: It remains unclear into which level the systolic blood pressure (SBP) should be lowered in order to provide the best cardiovascular protection among older people. Hypertension guidelines recommendation on attaining SBP levels 33,600 participants) were included. Compared with attaining SBP levels ≥140 mmHg, levels of 130 to <140 mmHg were not associated with lower risk of outcomes in the meta-analysis of RCTs, whereas there was an associated reduction of cardiovascular mortality (RR 0.72, 95% CI 0.59-0.88) and all-cause mortality (RR 0.86, 95% CI 0.75-0.99) in the meta-analysis of post-hoc analyses or subanalyses of RCTs. Limited and conflicting data were available for the SBP levels of <130 mmHg and 140 to <150 mmHg. Conclusions: Among older people, there is suggestive evidence that achieving SBP levels of 130 to <140 mmHg is associated with lower risks of cardiovascular and all-cause mortality. Future trials are required to confirm these findings and to provide additional evidence regarding the <130 and 140 to <150 mmHg SBP levels

    Phytostabilization of metals in mine soils using Brassica juncea in combination with organic amendments

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    Background and aims The high metal bioavailability and the poor conditions of mine soils yield a low plant biomass, limiting the application of phytoremediation techniques. A greenhouse experiment was performed to evaluate the effects of organic amendments on metal stabilization and the potential of Brassica juncea L. for phytostabilization in mine soils. Methods Plants were grown in pots filled with soils collected from two mine sites located in Central Spain mixed with 0, 30 and 60 tha?1 of pine bark compost and horse- and sheep-manure compost. Plant biomass and metal concentrations in roots and shoots were measured. Metal bioavailability was assessed using a rhizosphere-based method (rhizo), which consists of a mixture of low-molecular-weight organic acids to simulate root exudates. Results Manure reduced metal concentrations in shoots (10?50 % reduction of Cu and 40?80 % of Zn in comparison with non-amended soils), bioconcentration factor (10?50 % of Cu and 40?80 % of Zn) and metal bioavailability in soil (40?50 % of Cu and 10?30 % of Zn) due to the high pH and the contribution of organic matter. Manure improved soil fertility and was also able to increase plant biomass (5?20 times in shoots and 3?30 times in roots), which resulted in a greater amount of metals removed from soil and accumulated in roots (increase of 2?7 times of Cu and Zn). Plants grown in pine bark treatments and in non-amended soils showed a limited biomass and high metal concentrations in shoots. Conclusions The addition of manure could be effective for the stabilization of metals and for enhancing the phytostabilization ability of B. juncea in mine soils. In this study, this species resulted to be a potential candidate for phytostabilization in combination with manure, differing from previous results, in which B. juncea had been recognized as a phytoextraction plant

    Experiencing visual impairment in a lifetime home: an interpretative phenomenological inquiry

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    Lifetime home standards (LTHS) are a set of standards aimed at making homes more accessible. Previous research, however, indicates that LTHS do not adequately meet the needs of those with sensory impairments. Now, with visual impairment set to increase globally and acknowledging the recognised link between quality of dwelling and wellbeing, this article aims to examine the experiences of visually impaired people living in lifetime homes. The objectives are to investigate existing lifetime homes and to identify whether LTHS meet occupants’ needs. Qualitative semi-structured interviews were carried out with six visually impaired people living in homes designed to LTHS in Northern Ireland. Collected data was analysed using interpretative phenomenological analysis identifying three super-ordinate themes: (1) living with visual impairment; (2) design considerations and (3) coping strategies. A core theme of balance between psychological and physical needs emerged through interconnection of super-ordinate themes. Although there are benefits to living in lifetime homes, negative aspects are also apparent with occupants employing several coping strategies to overcome difficulties. Whilst residents experience negative emotions following visual impairment diagnoses, results suggest that occupants still regard their homes as key places of security and comfort in addition to then highlighting the need for greater consideration of specific individual needs within general guidelines
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