2,930 research outputs found

    Superconductivity at 17 K in Yttrium Metal under Nearly Hydrostatic Pressures to 89 GPa

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    In an experiment in a diamond anvil cell utilizing helium pressure medium, yttrium metal displays a superconducting transition temperature which increases monotonically from Tc ? 3.5 K at 30 GPa to 17 K at 89.3 GPa, one of the highest transition temperatures for any elemental superconductor. The pressure dependence of Tc differs substantially from that observed in previous studies under quasihydrostatic pressure to 30 GPa. Remarkably, the dependence of Tc on relative volume V/Vo is linear over the entire pressure range above 33 GPa, implying that higher values of Tc are likely at higher pressures. For the trivalent metals Sc, Y, La, Lu there appears to be some correlation between Tc and the ratio of the Wigner-Seitz radius to the ion core radius.Comment: submitted for publicatio

    Understanding urban inequalities in children's linear growth outcomes: a trend and decomposition analysis of 39,049 children in Bangladesh (2000-2018)

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    BACKGROUND: Despite significant progress in reducing child undernutrition, Bangladesh remains among the top six countries globally with the largest burden of child stunting and has disproportionately high stunting prevalence among the urban poor. We use population representative data to identify key predictors of child stunting in Bangladesh and assess their contributions to linear growth differences observed between urban poor and non-poor children. METHODS: We combined six rounds of Demographic and Health Survey data spanning 2000-2018 and used official poverty rates to classify the urban population into poor and non-poor households. We identified key stunting determinants using stepwise selection method. Regression-decomposition was used to quantify contributions of these key determinants to poverty-based intra-urban differences in child linear growth status. RESULTS: Key stunting determinants identified in our study predicted 84% of the linear growth difference between urban poor and non-poor children. Child's place of birth (27%), household wealth (22%), maternal education (18%), and maternal body mass index (11%) were the largest contributors to the intra-urban child linear growth gap. Difference in average height-for-age z score between urban poor and non-poor children declined by 0.31 standard deviations between 2000 and 2018. About one quarter of this observed decrease was explained by reduced differentials between urban poor and non-poor in levels of maternal education and maternal underweight status. CONCLUSIONS: Although the intra-urban disparity in child linear growth status declined over the 2000-2018 period, socioeconomic gaps remain significant. Increased nutrition-sensitive programs and investments targeting the urban poor to improve girls' education, household food security, and maternal and child health services could aid in further narrowing the remaining linear growth gap

    Imaging Biomarkers for Precision Medicine in Locally Advanced Breast Cancer

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    Guidelines from the American National Comprehensive Cancer Network (NCCN)recommend neoadjuvant chemotherapy (NAC) to patients with locally advanced breast cancer (LABC) to downstage tumors before surgery. However, only a small fraction (15-17%) of LABC patients achieve complete pathologic response (pCR), i.e. no residual tumor in the breast, after treatment. Measuring tumor response during 53 neoadjuvant chemotherapy can potentially help physicians adapt treatment thus, potentially improving the pCR rate. Recently, imaging biomarkers that are used to measure the tumor’s functional and biological features have been studied as pre-treatment markers for pCR or as an indicator for intra-treatment tumor response. Also, imaging biomarkers have been the focus of intense research to characterize tumor heterogeneity as well as to advance our understanding of the principle mechanisms behind chemoresistance. Advances in investigational radiology are moving rapidly to high-resolution imaging, capturing metabolic data, performing tissue characterization and statistical modelling of imaging biomarkers, with an endpoint of personalized medicine in breast cancer treatment. In this commentary, we present studies within the framework of imaging biomarkers used to measure breast tumor response to chemotherapy. Current studies are showing that significant progress has been made in the accuracy of measuring tumor response either before or during chemotherapy, yet the challenges at the forefront of these works include translational gaps such as needing large-scale clinical trials for validation, and standardization of imaging methods. However, the ongoing research is showing that imaging biomarkers may play an important role in personalized treatments for LABC

    Improving coverage of antenatal iron and folic acid supplementation and malaria prophylaxis through targeted information and home deliveries in Côte d'Ivoire: a cluster randomised controlled trial

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    INTRODUCTION: Coverage of antenatal iron and folic acid (IFA) supplementation and malaria chemoprophylaxis remains low in many low-income and middle-income settings. We assessed the effectiveness of personal information (INFO) sessions and personal information session plus home deliveries (INFO+DELIV) to increase coverage of IFA supplementation and intermittent preventive treatment in pregnancy (IPTp), and their effectiveness on postpartum anaemia and malaria infection. METHODS: We included 118 clusters randomised to a control (39), INFO (39) and INFO+DELIV (40) arm, in a trial conducted between 2020 and 2021 with pregnant women (age >/=15 years) in their first or second trimester of pregnancy in Taabo, Cote d'Ivoire. We used generalised linear regression models to assess intervention impact in postpartum anaemia and malaria parasitaemia, and displayed resulting estimates as prevalence ratios. RESULTS: Overall, 767 pregnant women were enrolled and 716 (93.3%) were followed up after delivery. Neither intervention had an impact on postpartum anaemia, with estimated adjusted prevalence ratios (aPRs) of 0.97 (95% CI 0.79 to 1.19, p=0.770) for INFO and 0.87 (95% CI 0.70 to 1.09, p=0.235) for INFO+DELIV. While INFO had no effect on malaria parasitaemia (aPR=0.95, 95% CI 0.39 to 2.31, p=0.915), INFO+DELIV reduced malaria parasitaemia by 83% (aPR=0.17, 95% CI 0.04 to 0.75, p=0.019). No improvements in antenatal care (ANC) coverage (aPR=1.05, 95% CI 0.81 to 1.36, p=0.692), IFA (aPR=2.00, 95% CI 0.89 to 4.46, p=0.093) and IPTp (aPR=1.03, 95% CI 0.87 to 1.21, p=0.728) compliance were found for INFO. INFO+DELIV increased ANC attendance (aPR=1.35, 95% CI 1.02 to 1.78, p=0.037) and compliance with IPTp (aPR=1.60, 95% CI 1.41 to 1.80, p<0.001) and IFA recommendations (aPR=7.06, 95% CI 3.68 to 13.51, p<0.001). CONCLUSIONS: INFO+DELIV can substantially increase compliance with IFA supplementation and improve malaria prevention. However, the increases in IFA supplementation are likely insufficient to address the prevalence of often severe anaemia in this population. TRIAL REGISTRATION NUMBER: NCT04250428

    Comb-calibrated solar spectroscopy through a multiplexed single-mode fiber channel

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    We investigate a new scheme for astronomical spectrograph calibration using the laser frequency comb at the Solar Vacuum Tower Telescope on Tenerife. Our concept is based upon a single-mode fiber channel, that simultaneously feeds the spectrograph with comb light and sunlight. This yields nearly perfect spatial mode matching between the two sources. In combination with the absolute calibration provided by the frequency comb, this method enables extremely robust and accurate spectroscopic measurements. The performance of this scheme is compared to a sequence of alternating comb and sunlight, and to absorption lines from Earth's atmosphere. We also show how the method can be used for radial-velocity detection by measuring the well-explored 5-minute oscillations averaged over the full solar disk. Our method is currently restricted to solar spectroscopy, but with further evolving fiber-injection techniques it could become an option even for faint astronomical targets.Comment: 21 pages, 11 figures. A video abstract for this paper is available on youtube. For watching the video, please follow https://www.youtube.com/watch?v=oshdZgrt89I . The video abstract is also available for streaming and download on the related article website of New Journal of Physic

    Study protocol of a cluster randomized controlled trial of strategies to increase antenatal iron and folic acid supplementation and malaria prophylaxis in rural south-central Côte d'Ivoire

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    BACKGROUND: Coverage of antenatal iron and folic acid supplementation (IFAS) and intermittent preventive treatment of malaria in pregnancy (IPTp) remains low in many countries. Evidence on the most effective ways to increase both IFASIPTp is mixed overall, with only few studies directly identifying cost-effective ways to increase coverage of both interventions. The proposed study aims to assess the cost, impact and relative cost-effectiveness of two complementary strategies of increasing IFAS and malaria chemoprophylaxis coverage among pregnant women relative to the current default system in a rural low-income setting of sub-Saharan Africa. METHODS/DESIGN: This study will be carried out in the Taabo health and demographic surveillance system (HDSS) in south-central Cote d'Ivoire. This is a cluster-randomized trial targeting 720 consenting pregnant women aged >/=15 years. The 118 clusters constituting the Taabo HDSS monitoring area will be randomly allocated to one of the following three groups with equal probability: a control group, an information only group, and an information plus home delivery group. To assess the relative effectiveness of each strategy, we will conduct an endline survey within the first 2 weeks after delivery. The primary outcomes of the trial will be maternal post-partum anaemia and malaria infection. Anaemia will be assessed using HEMOCUE devices; malaria infections will be assessed using standard rapid diagnostic tests named CareStart Malaria Pf (HRP2) Ag RDT (Multi Kit with capped lancet and inverted cup specimen transfer device). Other outcomes will include self-reported adherence to supplementation and malaria chemoprophylaxis, as well as miscarriages, stillbirths and low birth weight deliveries. DISCUSSION: This study will assess the cost-effectiveness of two alternative strategies to increase antenatal IFAS and malaria chemoprophylaxis coverage among pregnant women in rural Cote d'Ivoire and similar settings. TRIAL REGISTRATION: ClinicalTrials.gov NCT04250428 ; Registered 31 January 2020

    Association between mother's work status and child stunting in urban slums: a cross-sectional assessment of 346 child-mother dyads in Dhaka, Bangladesh (2020)

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    Background A growing literature highlights the increased risk of stunting among children growing up in informal or slum settlements. Despite relatively high rates of female labor force participation in slums, there is limited evidence on relationship between mother's work participation and nutritional outcomes of children in these settings. Methods We conducted a cross-sectional study in two large slums (Korail and Tongi) of Dhaka and Gazipur, Bangladesh to assess the association between maternal work and childhood stunting in a low-income urban context. Logistic regression models estimated unconditional and conditional associations between maternal work status and 1) child stunting, 2) child morbidity and dietary intake, and 3) health and hygiene behaviors. Subgroup analyses were done by type of child care support available. Results After adjusting for variations in individual and household level characteristics, we found that children of working mothers had nearly twice the odds of being stunted than children of non-working mothers (OR 1.84, 95%CI 1.05-3.23). Large differences in stunting were found by available care support: compared to children of non-working mothers, children of working mothers with nuclear-type family support had 4.5 times increased odds of stunting (OR 4.49, 95%CI 1.81-11.12), while no odds differential was found for children of working mothers with an extended-type family support (OR 0.69, 95%CI 0.30-1.59). Conclusions Maternal employment is associated with a substantial increase in the odds of child stunting in the slum areas studied. Given that these effects only appear to arise in the absence of adequate family support, integrating appropriate childcare support measures for low-income urban working mothers might be an effective strategy to help reduce the prevalence of chronic undernutrition among slum children

    Innovative Conservation Agriculture Approaches: Food Security and Climate Action through Soil and Water Conservation (INCAA)

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    The crucial challenge for smallholder farmers in sub-Saharan Africa is feeding a growing population while preserving the natural resource base of the agricultural system. In future, this challenge will be exacerbated by soil degradation and climate change. Conservation Agriculture (CA) has been promoted as a strategy that can improve yields, soils and effective water use. CA thus has potential to increase the resilience of farming systems facing the mentioned challenges. However, CA since its introduction in sub-Sahara Africa has not moved from the invention to the innovation stage: the CA innovation seen as a package is not meeting the farmers’ needs, capabilities and opportunities. Overall, the attempt to transfer this innovation in a conventional linear way from science to farm has been disappointing. The INCAA project is designed as an action research process aimed at targeting the challenging (and often missing) interfaces of science-driven technology and local realities in innovation systems. The overall objective of INCAA is to mentor and analyse a learning process that supports the innovation of CA in sub-Saharan Africa. The case studies of the project are Laikipia County, Kenya and Koumbia District, Burkina Faso. Building on the experiences of past projects, INCAA will (1) map benefits and adaptations of CA in innovation systems around the partner projects; (2) foster joined learning of stakeholders to test and validate CA tools; and (3) develop learning strategies for an innovation process towards CA including institutional and individual dimensions. This project will start from those who take the final decision on the fate of CA - the farmers. By assessing how farmers have actually adapted and implemented CA, we can derive lessons on the benefits and losses related to such CA modes for all stakeholders involved in the agricultural system. This contribution will 1) introduce the overall conceptual, methodological and structural design of the project and 2) highlight its first preliminary results which so far show high influence of gender aspects towards the adoption decision process. Differing roles of and expectations towards men and women within the farming communities are often an invisible obstacle for further adoption of CA

    Metastable anions of dinitrobenzene: resonances for electron attachment and kinetic energy release

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    Attachment of free, low-energy electrons to dinitrobenzene (DNB) in the gas phase leads to DNB as well as several fragment anions. DNB, (DNB-H), (DNB-NO), (DNB-2NO), and (DNB-NO(2)) are found to undergo metastable (unimolecular) dissociation. A rich pattern of resonances in the yield of these metastable reactions versus electron energy is observed; some resonances are highly isomer-specific. Most metastable reactions are accompanied by large average kinetic energy releases (KER) that range from 0.5 to 1.32 eV, typical of complex rearrangement reactions, but (1,3-DNB-H)(-) features a resonance with a KER of only 0.06 eV for loss of NO. (1,3-DNB-NO)(-) offers a rare example of a sequential metastable reaction, namely, loss of NO followed by loss of CO to yield C(5)H(4)O(-) with a large KER of 1.32 eV. The G4(MP2) method is applied to compute adiabatic electron affinities and reaction energies for several of the observed metastable channels. (C) 2010 American Institute of Physics. [doi:10.1063/1.3514931

    Impact of newly constructed primary healthcare centres on antenatal care attendance, facility delivery and all-cause mortality: quasi-experimental evidence from Taabo health and demographic surveillance system, Côte d'Ivoire

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    OBJECTIVES: Access to quality care remains limited, particularly in low-income and middle-income countries. Although better health outcomes for families living in close proximity to healthcare facilities have been documented in cross-sectional studies, evidence on the extent to which additional health facilities can contribute to improved population health remains scanty. We aimed to estimate the causal impact of newly constructed primary healthcare facilities within a health and demographic surveillance (HDSS) site in Cote d'Ivoire. DESIGN: We conducted a quasi-experimental study. Logistic and Cox proportional hazards regression models were used to estimate the impact of new healthcare facilities on healthcare-seeking behaviour and all-cause mortality. SETTING: Data were collected prospectively through the Taabo HDSS located in south-central Cote d'Ivoire between 2010 and 2018. PARTICIPANTS: We analysed 2957 deaths across 440 973 person-year observations as well as 14 132 live births. PRIMARY OUTCOME MEASURES: The primary outcomes were antenatal care (ANC) attendance, facility delivery and mortality. Logistic and Cox proportional hazards models were employed to estimate the impact of the new health facilities on ANC attendance, facility delivery and child as well as adult mortality. RESULTS: Average distance to the nearest healthcare facility declined from 5.5 km before to 2.8 km after opening of four new healthcare facilities in targeted villages. No improvement was observed for ANC attendance, institutional deliveries and adult mortality. New facilities reduced the risk of post-neonatal infant mortality by 46% (HR 0.54, 95% CI 0.31 to 0.94, p<0.05), suggesting a mortality gradient of 2 deaths per 1000 for each additional km (Coef=0.002, 95% CI 0.000 to 0.004, p<0.05). CONCLUSIONS: Our results suggest that new facilities do not necessarily improve healthcare utilisation and health outcomes. Further research is needed to identify the best ways to ensure access to quality care in resource-constrained settings
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