1,316 research outputs found

    Brain tissue properties differentiate between motor and limbic basal ganglia circuits

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    Despite advances in understanding basic organizational principles of the human basal ganglia, accurate in vivo assessment of their anatomical properties is essential to improve early diagnosis in disorders with corticosubcortical pathology and optimize target planning in deep brain stimulation. Main goal of this study was the detailed topological characterization of limbic, associative, and motor subdivisions of the subthalamic nucleus (STN) in relation to corresponding corticosubcortical circuits. To this aim, we used magnetic resonance imaging and investigated independently anatomical connectivity via white matter tracts next to brain tissue properties. On the basis of probabilistic diffusion tractography we identified STN subregions with predominantly motor, associative, and limbic connectivity. We then computed for each of the nonoverlapping STN subregions the covariance between local brain tissue properties and the rest of the brain using high-resolution maps of magnetization transfer (MT) saturation and longitudinal (R1) and transverse relaxation rate (R2*). The demonstrated spatial distribution pattern of covariance between brain tissue properties linked to myelin (R1 and MT) and iron (R2*) content clearly segregates between motor and limbic basal ganglia circuits. We interpret the demonstrated covariance pattern as evidence for shared tissue properties within a functional circuit, which is closely linked to its function. Our findings open new possibilities for investigation of changes in the established covariance pattern aiming at accurate diagnosis of basal ganglia disorders and prediction of treatment outcom

    Nutritional status of adolescent girls in a selected secondary school of north-eastern part of Nigeria

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    Background: Adolescence is the most critical period of human life when transitioning occurs from childhood to adulthood. Malnutrition is one of the major global health problems faced by many developing countries across the globe. Objectives: This study aimed to investigate the nutritional status of adolescent girls in a selected secondary school in Nigeria. Methods: A cross-sectional study was conducted on 250 adolescent girls who were available during the study period. A nutrition expert, together with an epidemiologist, gathered anthropometric information and measured the height, weight, and body mass index (BMI) of the participants. The BMI was calculated, and the dietary habits of the participants were reported based on their usual food habits. It is part of our limitations and has been addressed under the limitations. Data were collected using a self-administered and semi-structured questionnaire. Results: The mean age of the adolescent girls was 15.9 ± 0.9 years, and more than half (53.2%) were students of senior secondary class 1 (SS-1). More than half (54.4%) of the adolescent girls had average body weight, 36.0% were underweight, and only 9.6% were overweight. The following socio-demographic factors were significantly associated with the BMI of adolescent girls: Age, class of the students, monthly family income, mothers’ educational status, and area of residence. Close to four-fifths (78.4%) of the participants consumed rice more than twice in a week; more than eight-tenths (88.8%) of the participants consumed milk/milk products at least ≤ 2 in a week. About 84.4% of the participants took red meat at least ≤ 2 in a week; more than half (55.2%) of the participants consumed vegetables and fruits more than twice a week. Most (84.8%) of the participants took lunch regularly, and 91.6% of the adolescent girls took breakfast regularly. Conclusions: The study revealed that nearly one-third of the adolescent girls were underweight, indicating a severe public health concern. Early nutritional screening and interventions are recommended to improve the nutritional status of the adolescent girl school in Nigeria

    Travelling on Graphs with Small Highway Dimension

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    We study the Travelling Salesperson (TSP) and the Steiner Tree problem (STP) in graphs of low highway dimension. This graph parameter was introduced by Abraham et al. [SODA 2010] as a model for transportation networks, on which TSP and STP naturally occur for various applications in logistics. It was previously shown [Feldmann et al. ICALP 2015] that these problems admit a quasi-polynomial time approximation scheme (QPTAS) on graphs of constant highway dimension. We demonstrate that a significant improvement is possible in the special case when the highway dimension is 1, for which we present a fully-polynomial time approximation scheme (FPTAS). We also prove that STP is weakly NP-hard for these restricted graphs. For TSP we show NP-hardness for graphs of highway dimension 6, which answers an open problem posed in [Feldmann et al. ICALP 2015]

    How do patient feedback systems work in low-income and middle-income countries? Insights from a realist evaluation in Bangladesh

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    Background Well-functioning patient feedback systems can contribute to improved quality of healthcare and systems accountability. We used realist evaluation to examine patient feedback systems at health facilities in Bangladesh, informed by theories of citizenship and principal–agent relationships. Methods We collected and analysed data in two stages, using: document review; secondary analysis of data from publicly available web-portals; in-depth interviews with patients, health workers and managers; non-participant observations of feedback environments; and stakeholder workshops. Stage 1 focused on identifying and articulating the initial programme theory (PT) of patient feedback systems. In stage 2, we iteratively tested and refined this initial theory, through analysing data and grounding emerging findings within substantive theories and empirical literature, to arrive at a refined PT. Results Multiple patient feedback systems operate in Bangladesh, essentially comprising stages of collection, analysis and actions on feedback. Key contextual enablers include political commitment to accountability, whereas key constraints include limited patient awareness of feedback channels, lack of guidelines and documented processes, local political dynamics and priorities, institutional hierarchies and accountability relationships. Findings highlight that relational trust may be important for many people to exercise citizenship and providing feedback, and that appropriate policy and regulatory frameworks with clear lines of accountability are critical for ensuring effective patient feedback management within frontline healthcare facilities. Conclusion Theories of citizenship and principal–agent relationships can help understand how feedback systems work through spotlighting the citizenship identity and agency, shared or competing interests, and information asymmetries. We extend the understanding of these theories by highlighting how patients, health workers and managers act as both principals and agents, and how information asymmetry and possible agency loss can be addressed. We highlight the importance of awareness raising and non-threatening environment to provide feedback, adequate support to staff to document and analyse feedback and timely actions on the information

    A Double Sigma Model for Double Field Theory

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    We define a sigma model with doubled target space and calculate its background field equations. These coincide with generalised metric equation of motion of double field theory, thus the double field theory is the effective field theory for the sigma model.Comment: 26 pages, v1: 37 pages, v2: references added, v3: updated to match published version - background and detail of calculations substantially condensed, motivation expanded, refs added, results unchange

    Patient Feedback Systems at the Primary Level of Health Care Centres in Bangladesh: A Mixed Methods Study

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    This paper documents, and reflects on key strengths and weaknesses of, existing patient feedback management systems at primary health care in Bangladesh and proposes key implications for future policy and practice. A mixed-method study was conducted in two Upazila (sub-district) Health Complexes (UHC) within one district in Bangladesh. It reports qualitative data from thematic analysis of in-depth interviews (n = 15) with key stakeholders; non-participant observations of feedback environment at UHCs; document review; and a stakeholder workshop. Patient feedback data from publicly available web portals were also analyzed. Multiple parallel patient feedback systems exist at health facilities. Key strengths across all systems included common goals of ensuring accountability and patient voice and high-level commitment. Common weaknesses included lack of documented processes, limited awareness of available channels among patients and a lack of documented actions following feedback. The findings helped to provide a few implications for future policy and practice on patient feedback management

    Defining hypoxaemia from pulse oximeter measurements of oxygen saturation in well children at low altitude in Bangladesh: an observational study

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    BACKGROUND: WHO defines hypoxaemia, a low peripheral arterial oxyhaemoglobin saturation (SpO2), as <90%. Although hypoxaemia is an important risk factor for mortality of children with respiratory infections, the optimal SpO2 threshold for defining hypoxaemia is uncertain in low-income and middle-income countries (LMICs). We derived a SpO2 threshold for hypoxaemia from well children in Bangladesh residing at low altitude. METHODS: We prospectively enrolled well, children aged 3-35 months participating in a pneumococcal vaccine evaluation in Sylhet district, Bangladesh between June and August 2017. Trained health workers conducting community surveillance measured the SpO2 of children using a Masimo Rad-5 pulse oximeter with a wrap sensor. We used standard summary statistics to evaluate the SpO2 distribution, including whether the distribution differed by age or sex. We considered the 2.5th, 5th and 10th percentiles of SpO2 as possible lower thresholds for hypoxaemia. RESULTS: Our primary analytical sample included 1470 children (mean age 18.6±9.5 months). Median SpO2 was 98% (IQR 96%-99%), and the 2.5th, 5th and 10th percentile SpO2 was 91%, 92% and 94%. No child had a SpO2 <90%. Children 3-11 months had a lower median SpO2 (97%) than 12-23 months (98%) and 24-35 months (98%) (p=0.039). The SpO2 distribution did not differ by sex (p=0.959). CONCLUSION: A SpO2 threshold for hypoxaemia derived from the 2.5th, 5th or 10th percentile of well children is higher than <90%. If a higher threshold than <90% is adopted into LMIC care algorithms then decision-making using SpO2 must also consider the child's clinical status to minimise misclassification of well children as hypoxaemic. Younger children in lower altitude LMICs may require a different threshold for hypoxaemia than older children. Evaluating the mortality risk of sick children using higher SpO2 thresholds for hypoxaemia is a key next step

    COVID-19 outbreaks following full reopening of primary and secondary schools in England: Cross-sectional national surveillance, November 2020.

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    Background: The full reopening of schools in September 2020 was associated with an increase in COVID-19 cases and outbreaks in educational settings across England. Methods: Primary and secondary schools reporting an outbreak (≥2 laboratory-confirmed cases within 14 days) to Public Health England (PHE) between 31 August and 18 October 2020 were contacted in November 2020 to complete an online questionnaire. Interpretation: There were 969 school outbreaks reported to PHE, comprising 2% (n = 450) of primary schools and 10% (n = 519) of secondary schools in England. Of the 369 geographically-representative schools contacted, 179 completed the questionnaire (100 primary schools, 79 secondary schools) and 2,314 cases were reported. Outbreaks were larger and across more year groups in secondary schools than in primary schools. Teaching staff were more likely to be the index case in primary (48/100, 48%) than secondary (25/79, 32%) school outbreaks (P = 0.027). When an outbreak occurred, attack rates were higher in staff (881/17,362; 5.07; 95%CI, 4.75-5.41) than students, especially primary school teaching staff (378/3852; 9.81%; 95%CI, 8.90-10.82%) compared to secondary school teaching staff (284/7146; 3.97%; 95%CI, 3.79-5.69%). Secondary school students (1105/91,919; 1.20%; 95%CI, 1.13-1.28%) had higher attack rates than primary school students (328/39,027; 0.84%; 95%CI, 0.75-0.94%). Conclusions: A higher proportion of secondary schools than primary schools reported a COVID-19 outbreak and experienced larger outbreaks across multiple school year groups. The higher attack rate among teaching staff during an outbreak, especially in primary schools, suggests that additional protective measures may be needed. Funding: PHE

    Identification of QTLs for Arsenic Accumulation in Maize (Zea mays L.) Using a RIL Population

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    The Arsenic (As) concentration in different tissues of maize was analyzed using a set of RIL populations derived from an elite hybrid, Nongda108. The results showed that the trend of As concentration in the four measured tissues was leaves>stems>bracts>kernels. Eleven QTLs for As concentration were detected in the four tissues. Three QTLs for As concentration in leaves were mapped on chromosomes 1, 5, and 8, respectively. For As concentration in the bracts, two QTLs were identified, with 9.61% and 10.03% phenotypic variance. For As concentration in the stems, three QTLs were detected with 8.24%, 14.86%, and 15.23% phenotypic variance. Three QTLs were identified for kernels on chromosomes 3, 5, and 7, respectively, with 10.73%, 8.52%, and 9.10% phenotypic variance. Only one common chromosomal region between SSR marker bnlg1811 and umc1243 was detected for QTLs qLAV1 and qSAC1. The results implied that the As accumulation in different tissues in maize was controlled by different molecular mechanism. The study demonstrated that maize could be a useful plant for phytoremediation of As-contaminated paddy soil, and the QTLs will be useful for selecting inbred lines and hybrids with low As concentration in their kernels
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