Probing Current Sheet Instabilities from Flare Ribbon Dynamics

The presence of current sheet instabilities, such as the tearing mode instability, are needed to account for the observed rate of energy release in solar flares. Insights into these current sheet dynamics can be revealed by the behavior of flare ribbon substructure, as magnetic reconnection accelerates particles down newly reconnected field lines into the chromosphere to mark the flare footpoints. Behavior in the ribbons can therefore be used to probe processes occurring in the current sheet. In this study, we use high-cadence (1.7 s) IRIS Slit Jaw Imager observations to probe for the growth and evolution of key spatial scales along the flare ribbons—resulting from dynamics across the current sheet of a small solar flare on 2016 December 6. Combining analyses of spatial scale growth with Si iv nonthermal velocities, we piece together a timeline of flare onset for this confined event, and provide evidence of the tearing mode instability triggering a cascade and inverse cascade toward a power spectrum consistent with plasma turbulence

A Trial of a 7-Valent Pneumococcal Conjugate Vaccine in HIV-Infected Adults.

BACKGROUND: Streptococcus pneumoniae is a leading and serious coinfection in adults with human immunodeficiency virus (HIV) infection, particularly in Africa. Prevention of this disease by vaccination with the current 23-valent polysaccharide vaccine is suboptimal. Protein conjugate vaccines offer a further option for protection, but data on their clinical efficacy in adults are needed. METHODS: In this double-blind, randomized, placebo-controlled clinical efficacy trial, we studied the efficacy of a 7-valent conjugate pneumococcal vaccine in predominantly HIV-infected Malawian adolescents and adults who had recovered from documented invasive pneumococcal disease. Two doses of vaccine were given 4 weeks apart. The primary end point was a further episode of pneumococcal infection caused by vaccine serotypes or serotype 6A. RESULTS: From February 2003 through October 2007, we followed 496 patients (of whom 44% were male and 88% were HIV-seropositive) for 798 person-years of observation. There were 67 episodes of pneumococcal disease in 52 patients, all in the HIV-infected subgroup. In 24 patients, there were 19 episodes that were caused by vaccine serotypes and 5 episodes that were caused by the 6A serotype. Of these episodes, 5 occurred in the vaccine group and 19 in the placebo group, for a vaccine efficacy of 74% (95% confidence interval [CI], 30 to 90). There were 73 deaths from any cause in the vaccine group and 63 in the placebo group (hazard ratio in the vaccine group, 1.18; 95% CI, 0.84 to 1.66). The number of serious adverse events within 14 days after vaccination was significantly lower in the vaccine group than in the placebo group (3 vs. 17, P=0.002), and the number of minor adverse events was significantly higher in the vaccine group (41 vs. 13, P=0.003). CONCLUSIONS: The 7-valent pneumococcal conjugate vaccine protected HIV-infected adults from recurrent pneumococcal infection caused by vaccine serotypes or serotype 6A. (Current Controlled Trials number, ISRCTN54494731.) Copyright 2010 Massachusetts Medical Society

Elderly musculoskeletal disease burden in Karachi, Pakistan: Associations and implications for developing countries

Objective: The global rise in the older population has increased the rates of osteoporosis and osteoarthritis, conditions that impact mobility and functionality. There is limited data on musculoskeletal disease in older populations residing in developing countries.Methods: A community-based study using multistage cluster random sampling of older individuals was conducted in Karachi. Predefined criteria were used for osteoporosis and osteoarthritis. Gait assessment was performed.Results: More than half of the participants were females and 53% reported illiteracy. Around 30% had osteoporosis and two-thirds had osteoarthritis. Multivariate analysis showed associations of female sex, Pashtun ethnicity, illiteracy, and hypertension with the combined variable of osteoporosis and osteoarthritis.Conclusions: The prevalence of osteoarthritis was higher than in other regional studies. Presence of both osteoporosis and osteoarthritis increased the risk of certain geriatric syndromes. High rates of musculoskeletal morbidity are seen in the elderly in Pakistan. Measures at a health-system level are required for better outcomes in older adults

Challenges in lifestyle and community interventions research; a call for innovation

Earlier this year the BMC portfolio was enriched by a new journal BMC Obesity. Here, we present the aims and objectives of the section on Lifestyle and Community Interventions. Innovative research is needed. Preventing or managing obesity requires addressing different determinants across multiple levels where diverse levers and stakeholders can play a critical role. Interactions of these determinants within and between systems need to be studied. How to leverage, manage and measure this complexity underlies the innovation that is needed in the next generation of obesity interventions. The ambition of the Lifestyle and Community Interventions section is to provide a space for innovative research, including research that falls outside the traditional comfort zone. We welcome studies of heterogeneous designs, including those of qualitative, quantitative, mixed and systems methodologies. Studies of interest include not only outcomes research of interventions but also process evaluation, cost-effectiveness or cost-benefit analysis, and implementation and dissemination research. Innovations that integrate diverse intervention levers or combine primary and secondary levels of prevention are particularly encouraged. The general aim of BMC Obesity’s Lifestyle and Community Interventions section is to advance our ability to decide on what combinations of approaches will be required to effectively and equitably prevent obesity

Who does not gain weight? Prevalence and predictors of weight maintenance in young women

OBJECTIVE: To investigate the prevalence and predictors of weight maintenance over time in a large sample of young Australian women. DESIGN: This population study examined baseline and 4 y follow-up data from the cohort of young women participating in the Australian Longitudinal Study on Women\u27s Health. SUBJECTS: A total of 8726 young women aged 18-23 y at baseline. MEASURES: Height, weight and body mass index (BMI); physical activity; time spent sitting; selected eating behaviours (eg dieting, disordered eating, takeaway food consumption); cigarette smoking, alcohol consumption; parity; and sociodemographic characteristics. RESULTS: Only 44% of the women reported their BMI at follow-up to be within 5% of their baseline BMI (maintainers); 41% had gained weight and 15% had lost weight. Weight maintainers were more likely to be in managerial or professional occupations; to have never married; to be currently studying; and not to be mothers. Controlling for sociodemographic factors, weight maintainers were more likely to be in a healthy weight range at baseline, and to report that they spent less time sitting, and consumed less takeaway food, than women who gained weight. CONCLUSIONS: Fewer than half the young women in this community sample maintained their weight over this 4 y period in their early twenties. Findings of widespread weight gain, particularly among those already overweight, suggest that early adulthood, which is a time of significant life changes for many women, may be an important time for implementing strategies to promote maintenance of healthy weight. Strategies which encourage decreased sitting time and less takeaway food consumption may be effective for encouraging weight maintenance at this life stage.<br /

The prevalence and risk of immune restoration disease in HIV-infected patients treated with highly active antiretroviral therapy

Background It is becoming increasingly clear that, during successful highly active antiretroviral therapy (HAART), a proportion of treated patients develop opportunistic infections (OIs), referred to in this setting as immune restoration disease (IRD). We examined the risk of developing IRD in HAART-treated HIV-infected patients. Methods A retrospective study of a cohort including all 389 patients treated with HAART between I January 1998 and 31 May 2004 in our HIV unit was performed to evaluate the occurrence of and risk factors for IRD during HAART. Baseline and follow-up values of CD4 T-cell counts and plasma viral loads (pVLs) were compared to assess the success of HAART. Results During successful HAART (significant increase in CD4 T-cell counts and decrease in pVL), at least one IRD episode occurred in 65 patients (16.7%). The median time to IRD was 4.6 months (range 212 months). IRDs included dermatomal herpes zoster (26 patients), pulmonary tuberculosis (four patients), tuberculous exudative pericarditis (two patients), tuberculous lymphadenitis (two patients), cerebral toxoplasmosis (one patient), progressive multifocal leucoencephalopathy (PML) (one patient), inflamed molluscum (one patient), inflamed Candida albicans angular cheilitis (three patients), genital herpes simplex (two patients), tinea corporis (two patients), cytomegalovirus (CMV) retinitis (two patients), CMV vitritis (one patient) and hepatitis B (three patients) or C (fifteen patients). A baseline CD4 T-cell count below 100 cells/mu L was shown to be the single predictor [odds ratio (OR) 2.5, 95% confidence interval (CI) 0.9-6.4] of IRD, while a CD4 T-cell count increase to gt 400 cells/mu L, but not undetectable pVL, was a negative predictor of IRD (OR 0.3, 95% CI 0.1-0.8). Conclusions To avoid IRD in advanced patients, HAART should be initiated before the CD4 T-cell count falls below 100 cells/mu L

Sr-Nd isotope geochemistry of the early Precambrian sub-alkaline mafic igneous rocks from the southern Bastar craton, Central India

Sr–Nd isotope data are reported for the early Precambrian sub-alkaline mafic igneous rocks of the southern Bastar craton, central India. These mafic rocks are mostly dykes but there are a few volcanic exposures. Field relationships together with the petrological and geochemical characteristics of these mafic dykes divide them into two groups; Meso-Neoarchaean sub-alkaline mafic dykes (BD1) and Paleoproterozoic (1.88 Ga) sub-alkaline mafic dykes (BD2). The mafic volcanics are Neoarchaean in age and have very close geochemical relationships with the BD1 type. The two groups have distinctly different concentrations of high-field strength (HFSE) and rare earth elements (REE). The BD2 dykes have higher concentrations of HFSE and REE than the BD1 dykes and associated volcanics and both groups have very distinctive petrogenetic histories. These rocks display a limited range of initial 143Nd/144Nd but a wide range of apparent initial 87Sr/86Sr. Initial 143Nd/144Nd values in the BD1 dykes and associated volcanics vary between 0.509149 and 0.509466 and in the BD2 dykes the variation is between 0.510303 and 0.510511. All samples have positive &#949;Nd values the BD1 dykes and associated volcanics have &#949;Nd values between +0.3 and +6.5 and the BD2 dykes between +1.9 to +6.0. Trace element and Nd isotope data do not suggest severe crustal contamination during the emplacement of the studied rocks. The positive &#949;Nd values suggest their derivation from a depleted mantle source. Overlapping positive &#949;Nd values suggest that a similar mantle source tapped by variable melt fractions at different times was responsible for the genesis of BD1 (and associated volcanics) and BD2 mafic dykes. The Rb–Sr system is susceptible to alteration and resetting during post-magmatic alteration and metamorphism. Many of the samples studied have anomalous apparent initial 87Sr/86Sr suggesting post-magmatic changes of the Rb–Sr system which severely restricts the use of Rb–Sr for petrogenetic interpretation

AutoRoot: open-source software employing a novel image analysis approach to support fully-automated plant phenotyping

Background: Computer-based phenotyping of plants has risen in importance in recent years. Whilst much software has been written to aid phenotyping using image analysis, to date the vast majority has been only semi-automatic. However, such interaction is not desirable in high throughput approaches. Here, we present a system designed to analyse plant images in a completely automated manner, allowing genuine high throughput measurement of root traits. To do this we introduce a new set of proxy traits. Results: We test the system on a new, automated image capture system, the Microphenotron, which is able to image many 1000s of roots/h. A simple experiment is presented, treating the plants with differing chemical conditions to produce different phenotypes. The automated imaging setup and the new software tool was used to measure proxy traits in each well. A correlation matrix was calculated across automated and manual measures, as a validation. Some particular proxy measures are very highly correlated with the manual measures (e.g. proxy length to manual length, r2 > 0.9). This suggests that while the automated measures are not directly equivalent to classic manual measures, they can be used to indicate phenotypic differences (hence the term, proxy). In addition, the raw discriminative power of the new proxy traits was examined. Principal component analysis was calculated across all proxy measures over two phenotypically-different groups of plants. Many of the proxy traits can be used to separate the data in the two conditions. Conclusion: The new proxy traits proposed tend to correlate well with equivalent manual measures, where these exist. Additionally, the new measures display strong discriminative power. It is suggested that for particular phenotypic differences, different traits will be relevant, and not all will have meaningful manual equivalent measures. However, approaches such as PCA can be used to interrogate the resulting data to identify differences between datasets. Select images can then be carefully manually inspected if the nature of the precise differences is required. We suggest such flexible measurement approaches are necessary for fully automated, high throughput systems such as the Microphenotron

Who bullies whom at a garden feeder? Interspecific agonistic interactions of small passerines during a cold winter

Interspecific agonistic interactions are important selective factors for maintaining ecological niches of different species, but their outcome is difficult to predict a priori. Here, we examined the direction and intensity of interspecific interactions in an assemblage of small passerines at a garden feeder, focussing on three finch species of various body sizes. We found that large and mediumsized birds usually initiated and won agonistic interactions with smaller species. Also, the frequency of fights increased with decreasing differences in body size between the participants. Finally, the probability of engaging in a fight increased with the number of birds at the feeder

The virtual supermarket: An innovative research tool to study consumer food purchasing behaviour

<p>Abstract</p> <p>Background</p> <p>Economic interventions in the food environment are expected to effectively promote healthier food choices. However, before introducing them on a large scale, it is important to gain insight into the effectiveness of economic interventions and peoples' genuine reactions to price changes. Nonetheless, because of complex implementation issues, studies on price interventions are virtually non-existent. This is especially true for experiments undertaken in a retail setting. We have developed a research tool to study the effects of retail price interventions in a virtual-reality setting: the Virtual Supermarket. This paper aims to inform researchers about the features and utilization of this new software application.</p> <p>Results</p> <p>The Virtual Supermarket is a Dutch-developed three-dimensional software application in which study participants can shop in a manner comparable to a real supermarket. The tool can be used to study several food pricing and labelling strategies. The application base can be used to build future extensions and could be translated into, for example, an English-language version. The Virtual Supermarket contains a front-end which is seen by the participants, and a back-end that enables researchers to easily manipulate research conditions. The application keeps track of time spent shopping, number of products purchased, shopping budget, total expenditures and answers on configurable questionnaires. All data is digitally stored and automatically sent to a web server. A pilot study among Dutch consumers (n = 66) revealed that the application accurately collected and stored all data. Results from participant feedback revealed that 83% of the respondents considered the Virtual Supermarket easy to understand and 79% found that their virtual grocery purchases resembled their regular groceries.</p> <p>Conclusions</p> <p>The Virtual Supermarket is an innovative research tool with a great potential to assist in gaining insight into food purchasing behaviour. The application can be obtained via an URL and is freely available for academic use. The unique features of the tool include the fact that it enables researchers to easily modify research conditions and in this way study different types of interventions in a retail environment without a complex implementation process. Finally, it also maintains researcher independence and avoids conflicts of interest that may arise from industry collaboration.</p