Effects of zinc on microalgal biofilms in intertidal and subtidal habitats

Microalgal biofilms are sensitive to environmental conditions. Impacts of contaminants on assemblages of marine biofilm are often investigated in laboratories or in mesocosms. Such experiments are rarely representative of the effects of contaminants on biofilms under natural conditions. Studies in field situations, with enough power to detect impacts, are necessary to develop a better understanding of the effects of contaminants on ecological processes. Metals are a common contaminant of marine systems and can cause disturbances to assemblages. Using a new technique to experimentally deliver contaminants to microalgal assemblages, hypotheses were tested regarding the effects of zinc on microalgal biofilms growing on settlement panels in subtidal and intertidal habitats. PAM fluorometry was used to assess the amount and physiological state of biofilms on panels. Control panels deployed for 1 month in each habitat had significantly greater amounts of biofilm than those exposed to zinc. After deployment for 3 months, the results varied with location. The observed effects on the biofilm did not, however, cause significant changes in the macro-invertebrate assemblages that developed on the panels

A dual telescope for spectroheliography in the extreme ultra-violet

Dual reflecting telescope design for ultraviolet spectroheliograph

Inlet protein aggregation: a new mechanism for lubricating film formation with model synovial fluids.

This paper reports a fundamental study of lubricant film formation with model synovial fluid components (proteins) and bovine serum (BS). The objective was to investigate the role of proteins in the lubrication process. Film thickness was measured by optical interferometry in a ball-on-disc device (mean speed range of 2-60 mm/s). A commercial cobalt-chromium (CoCrMo) metal femoral head was used as the stationary component. The results for BS showed complex time-dependent behaviour, which was not representative of a simple fluid. After a few minutes sliding BS formed a thin adherent film of 10-20 nm, which was attributed to protein absorbance at the surface. This layer was augmented by a hydrodynamic film, which often increased at slow speeds. At the end of the test deposited surface layers of 20-50 nm were measured. Imaging of the contact showed that at slow speeds an apparent 'phase boundary' formed in the inlet just in front of the Hertzian zone. This was associated with the formation of a reservoir of high-viscosity material that periodically moved through the contact forming a much thicker film. The study shows that proteins play an important role in the film-forming process and current lubrication models do not capture these mechanisms

Guidelines for Evaluation and Management of Cognitive Disorders in HIV-Positive Individuals

Antiretroviral therapy has revolutionised the treatment for people living with HIV (PLWH). Where antiretroviral coverage is high, the treatment paradigm for HIV-disease is now one of managing the long-term consequences of the virus and its treatment rather than the consequences of untreated HIV-disease such as immunosuppression and opportunistic infections. One such long-term consequence is HIV-associated cognitive impairment which is reported to occur in up to 50 % of treated PLWH and has been associated with poorer outcomes. Given the ageing cohort and increased frequency of comorbidities, the prevalence of symptomatic cognitive impairment may increase with time. High quality evidence for management strategies including screening, diagnosis and treatment of HIV-associated cognitive impairment are lacking and in general guidelines are based on best clinical practice. In this article, we assessed recent guidelines concerning the management of HIV-associated cognitive impairment by performing a systematic review of the MEDLINE database using PubMed. We report that, in general, guidelines from around the world regarding the management of HIV-associated cognitive impairment are converging. Screening is generally not recommended in asymptomatic PLWH. Diagnosis of HIV-associated cognitive impairment should be made only after a comprehensive assessment and exclusion of other potential causes. Antiretroviral therapy forms the cornerstone of management of HIV-associated cognitive impairment and should be guided by plasma and cerebrospinal fluid (CSF) genotype(s)

Cladding strategies for building-integrated photovoltaics

Photovoltaic cladding on the surfaces of commercial buildings has the potential for considerable reductions in carbon emissions due to embedded renewable power generation displacing conventional power utilization. In this paper, a model is described for the optimization of photovoltaic cladding densities on commercial building surfaces. The model uses a modified form of the ‘fill factor’ method for photovoltaic power supply coupled to new regression-based procedures for power demand estimation. An optimization is included based on a defined ‘mean index of satisfaction’ for matched power supply and demand (i.e., zero power exportation to the grid). The mean index of satisfaction directly translates to the reduction in carbon emission that might be expected over conventional power use. On clear days throughout the year, reductions of conventional power use of at least 60% can be achieved with an optimum cladding pattern targeted to lighting and small power load demands

Digestion of Protein in Premature and Term Infants.

Premature birth rates and premature infant morbidity remain discouragingly high. Improving nourishment for these infants is the key for accelerating their development and decreasing disease risk. Dietary protein is essential for growth and development of infants. Studies on protein nourishment for premature infants have focused on protein requirements for catch-up growth, nitrogen balance, and digestive protease concentrations and activities. However, little is known about the processes and products of protein digestion in the premature infant. This review briefly summarizes the protein requirements of term and preterm infants, and the protein content of milk from women delivering preterm and at term. An in-depth review is presented of the current knowledge of term and preterm infant dietary protein digestion, including human milk protease and anti-protease concentrations; neonatal intestinal pH, and enzyme activities and concentrations; and protein fermentation by intestinal bacteria. The advantages and disadvantages of incomplete protein digestion as well as factors that increase resistance to proteolysis of particular proteins are discussed. In order to better understand protein digestion in preterm and term infants, future studies should examine protein and peptide fragment products of digestion in saliva, gastric, intestinal and fecal samples, as well as the effects of the gut micro biome on protein degradation. The confluence of new mass spectrometry technology and new bioinformatics programs will now allow thorough identification of the array of peptides produced in the infant as they are digested

Switched wave packets: A route to nonperturbative quantum control

The dynamic Stark effect due to a strong nonresonant but nonionizing laser field provides a route to quantum control via the creation of novel superposition states. We consider the creation of a field-free "switched" wave packet through adiabatic turn-on and sudden turn-off of a strong dynamic Stark interaction. There are two limiting cases for such wave packets. The first is a Raman-type coupling, illustrated by the creation of field-free molecular axis alignment. An experimental demonstration is given. The second case is that of dipole-type coupling, illustrated by the creation of charge localization in an array of quantum wells

Transition between educational sectors and discontinuities of ICT resource and pedagogy

Technologically supported education has introduced benefits but also challenges to the transition across school levels of education. While resolving some traditional issues, these technologies have in some instances created a new set of discontinuities at both the resource and pedagogic level. These discontinuities arise due to variance between primary and secondary school access and practice, and also between pupils' experiences of access and practice at previous institutions. In this paper evidence is presented from interview, questionnaire, and classroom observation data collected from 48 schools during two projects investigating the impact of high-speed Internet access (broadband) in English schools. Findings indicate that schools offer different levels of access to technology, and also different activities when using technology facilities. While differences in practice have always been present across and within levels of education, the introduction of high-speed Internet access has increased the gap between those using the technology as an add-on to existing resources and those embedding the technological facilities into the fabric of the learning environment. A key issue explored is the impact of the discontinuity that occurs when primary (elementary school) education becomes technically richer than partner secondary (high school) institutions

Pain management for chronic musculoskeletal conditions : the development of an evidence-based and theory-informed pain self-management course

Objective: To devise and test a self-management course for chronic pain patients based on evidence and underpinned by theory using the Medical Research Council (MRC) framework for developing complex interventions. Design: We used a mixed method approach. We conducted a systematic review of the effectiveness of components and characteristics of pain management courses. We then interviewed chronic pain patients who had attended pain and self-management courses. Behavioural change theories were mapped onto our findings and used to design the intervention. We then conducted a feasibility study to test the intervention. Setting: Primary care in the inner city of London, UK. Participants: Adults (18 years or older) with chronic musculoskeletal pain. Outcomes: Related disability, quality of life, coping, depression, anxiety, social integration and healthcare resource use. Results: The systematic reviews indicated that group-based courses with joint lay and healthcare professional leadership and that included a psychological component of short duration (<8 weeks) showed considerable promise. The qualitative research indicated that participants liked relaxation, valued social interaction and course location, and that timing and good tutoring were important determinants of attendance. We used behavioural change theories (social learning theory and cognitive behaviour approaches (CBA)) to inform course content. The course addressed: understanding and accepting pain, mood and pain, unhelpful thoughts and behaviour, problem solving, goal setting, action planning, movement, relaxation and social integration/reactivation. Attendance was 85%; we modified the recruitment of patients, the course and the training of facilitators as a result of testing. Conclusions: The MRC guidelines were helpful in developing this intervention. It was possible to train both lay and non-psychologists to facilitate the courses and deliver CBA. The course was feasible and well received