3,109 research outputs found
Evolution of a stream ecosystem in recently deglaciated terrain
Climate change and associated glacial recession create new stream habitat that leads to the assembly of new riverine communities through primary succession. However, there are still very few studies of the patterns and processes of community assembly during primary succession for stream ecosystems. We illustrate the rapidity with which biotic communities can colonize and establish in recently formed streams by examining Stonefly Creek in Glacier Bay, Alaska (USA), which began to emerge from a remnant glacial ice mass between 1976 and 1979. By 2002, 57 macroinvertebrate and 27 microcrustacea species had become established. Within 10 years of the stream's formation, pink salmon and Dolly Varden charr colonized, followed by other fish species, including juvenile red and silver salmon, Coast Range sculpin, and sticklebacks. Stable-isotope analyses indicate that marine-derived nitrogen from the decay of salmon carcasses was substantially assimilated within the aquatic food web by 2004. The findings from Stonefly Creek are compared with those from a long-term study of a similarly formed but older stream (12 km to the northeast) to examine possible similarities in macroinvertebrate community and biological trait composition between streams at similar stages of development. Macroinvertebrate community assembly appears to have been initially strongly deterministic owing to low water temperature associated with remnant ice masses. In contrast, microcrustacean community assembly appears to have been more stochastic. However, as stream age and water temperature increased, macroinvertebrate colonization was also more stochastic, and taxonomic similarity between Stonefly Creek and a stream at the same stage of development was,<50%. However the most abundant taxa were similar, and functional diversity of the two communities was almost identical. Tolerance is suggested as the major mechanism of community assembly. The rapidity with which salmonids and invertebrate communities have become established across an entire watershed has implications for the conservation of biodiversity in freshwater habitats
What is the current NHS service provision for patients severely affected by chronic fatigue syndrome/myalgic encephalomyelitis? A national scoping exercise
Background: Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME), in its most severe clinical presentation, can result in patients becoming housebound and bedbound so unable to access most available specialist services. This presents particular clinical risks and treatment needs for which the National Institute for Health and Care Excellence (NICE) advises specialist medical care and monitoring. The extent of National Health Service (NHS) specialist provision in England for severe CFS/ME is currently unknown.
Objectives: To establish the current NHS provision for patients with severe CFS/ME in England.
Setting and participants: All 49 English NHS specialist CFS/ME adult services in England, in 2013.
Method: Cross-sectional survey by email questionnaire.
Primary outcome measures: Adherence to NICE guidelines for severe CFS/ME.
Results: All 49 services replied (100%). 33% (16/49) of specialist CFS/ME services provided no service for housebound patients. 55% (27/49) services did treat patients with severe CFS/ME and their interventions followed the NICE guidelines. The remaining services (12%, 6/49) offered occasional or minimal support where funding allowed. There was one NHS unit providing specialist inpatient CFS/ME provision in England.
Conclusions: Study findings highlight substantial variation in access to specialist care for patients with severe presentation of CFS/ME. Where treatment was provided, this appeared to comply with NICE recommendations for this patient group
Costs and cost effectiveness of cardiovascular screening and intervention: The British family heart study
This article has been made available through the Brunel Open Access Publishing Fund and is available from the specified link - Copyright @ 1996 BMJ Publishing Group.Objective-To measure costs and cost effectiveness of the British family heart study cardiovascular screening and intervention programme.Design-Cost effectiveness analysis of randomised controlled trial. Clinical and resource use data taken from trial and unit cost data from external estimates.Setting-13 general practices across Britain.Subjects-4185 men aged 40-59 and their 2827 partners.Intervention-Nurse led programme using a family centred approach, with follow up according to degree of risk.Main outcome measures-Cost of the programme itself; overall short term cost to NHS; cost per 1% reduction in coronary risk at one year.Results-Estimated cost of putting the programme into practice for one year was pound 63 per person (95% confidence interval pound 60 to pound 65). The overall short term cost to the health service was pound 77 per man (pound 29 to pound 124) but only pound 13 per woman (-pound 48 to pound 74), owing to differences in utilisation of other health service resources. The cost per 1% reduction in risk was pound 5.08 per man (pound 5.92 including broader health service costs) and pound 5.78 per woman (pound 1.28 taking into account wider health service savings).Conclusions-The direct cost of the programme to a four partner practice of 7500 patients would be approximately pound 58 000. Annually, pound 8300 would currently be paid to a practice of this size working to the ma target on the health promotion bands, plus any additional reimbursement of practice staff salaries for which the practice qualified. The broader short term costs to the NHS may augment these costs for men but offset them considerably for women
Photoinitiated polymerisation of monolithic stationary phases in polyimide coated capillaries using visible region LEDs
The spatially controlled synthesis of poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolithic stationary phases in polyimide coated fused silica capillaries by visible light induced radical polymerisation using a three-component initiator and a 660 nm light emitting diode (LED) as a light source is presented here
Nuclei in Strongly Magnetised Neutron Star Crusts
We discuss the ground state properties of matter in outer and inner crusts of
neutron stars under the influence of strong magnetic fields. In particular, we
demonstrate the effects of Landau quantization of electrons on compositions of
neutron star crusts. First we revisit the sequence of nuclei and the equation
of state of the outer crust adopting the Baym, Pethick and Sutherland (BPS)
model in the presence of strong magnetic fields and most recent versions of the
theoretical and experimental nuclear mass tables. Next we deal with nuclei in
the inner crust. Nuclei which are arranged in a lattice, are immersed in a
nucleonic gas as well as a uniform background of electrons in the inner crust.
The Wigner-Seitz approximation is adopted in this calculation and each lattice
volume is replaced by a spherical cell. The coexistence of two phases of
nuclear matter - liquid and gas, is considered in this case. We obtain the
equilibrium nucleus corresponding to each baryon density by minimizing the free
energy of the cell. We perform this calculation using Skyrme nucleon-nucleon
interaction with different parameter sets. We find nuclei with larger mass and
charge numbers in the inner crust in the presence of strong magnetic fields
than those of the zero field case for all nucleon-nucleon interactions
considered here. However, SLy4 interaction has dramatic effects on the proton
fraction as well as masses and charges of nuclei. This may be attributed to the
behaviour of symmetry energy with density in the sub-saturation density regime.
Further we discuss the implications of our results to shear mode oscillations
of magnetars.Comment: presented in "Exciting Physics Symposium" held in Makutsi, South
Africa in November, 2011 and to be published in a book by Springer Verla
Systematic review of brucellosis in the Middle East: disease frequency in ruminants and humans and risk factors for human infection
Seroprevalence and risk factors for bovine brucellosis in Jordan
We investigated the seroprevalence and risk factors for Brucella seropositivity in cattle in Jordan. The sera from 671 cows were randomly collected from 62 herds. The antibodies against Brucella were detected using a Rose Bengal plate test and indirect ELISA. A structured questionnaire was used to collect information on the cattle herds' health and management. A multiple logistic regression model was constructed to identify the risk factors for Brucella seropositivity. The true prevalence of antibodies against Brucella in individual cows and cattle herds was 6.5% and 23%, respectively. The seroprevalence of brucellosis in cows older than 4 years of age was significantly higher than that in the younger cows. The seroprevalence of brucellosis in cows located in the Mafraq, Zarqa and Ma'an governorates was significantly higher than that of the other studied governorates. The multiple logistic regression model revealed that a larger herd size (odd ratio <OR> = 1.3; 95% CI: 1.1, 2.6) and mixed farming (OR = 2.0; 95% CI: 1.7, 3.7) were risk factors for cattle seropositivity to Brucella antigens. On the other hand, the use of disinfectants (OR = 1.9; 95% CI: 1.1, 2.1) and the presence of adequate veterinary services (OR = 1.6; 95% CI: 1.2, 3.2) were identified as protective factors
Brucellosis remains a neglected disease inthe developing world: a call forinterdisciplinary action
Brucellosis places significant burdens on the human healthcare system and limits the economic growth of individuals, communities, and nations where such development is especially important to diminish the prevalence of poverty. The implementation of public policy focused on mitigating the socioeconomic effects of brucellosis in human and animal populations is desperately needed. When developing a plan to mitigate the associated consequences, it is vital to consider both the abstract and quantifiable effects. This requires an interdisciplinary and collaborative, or One Health, approach that consists of public education, the development of an infrastructure for disease surveillance and reporting in both veterinary and medical fields, and campaigns for control in livestock and wildlife species
- …