373 research outputs found

    A dataset of community perspectives on living conditions and disaster risk management in informal settlements: A case study in KwaZulu-Natal Province, South Africa

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    This article describes a dataset of community perspectives on living conditions and disaster risk management in Khan Road, a non-serviced informal settlement, located in Pietermaritzburg, the capital of KwaZulu-Natal province in South Africa. The data were collected by local community researchers via a structured questionnaire of 159 informal dwellers conducted between August and September 2022, using mobile phones via KoboToolbox. The dataset was analysed using exploratory data analysis (EDA) techniques. This household survey is part of a research project aiming to develop an evidence base of opportunities, risks and vulnerabilities related to housing construction and resource management in incremental upgrading of informal settlements in South Africa. This dataset can be used by local practitioners and policymakers involved in decision-making for informal settlement upgrading and help them prioritise resources and upgrading interventions based on what informal dwellers need. Furthermore, this cleaned dataset could support the analysis of further South African data guiding the development of digital platforms as a real-time resource management tool or guide the enhancement of existing theoretical frameworks in the field of participatory design and co-production used by academic scholars

    Ab initioAb\ initio molecular dynamics of temporary anions using complex absorbing potentials

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    Dissociative electron attachment, that is, the cleavage of chemical bonds induced by low-energy electrons, is difficult to model with standard quantum-chemical methods because the involved anions are not bound but subject to autodetachment. We present here a new computational development for simulating the dynamics of temporary anions on complex-valued potential energy surfaces. The imaginary part of these surfaces describes electron loss, whereas the gradient of the real part represents the force on the nuclei. In our method, the forces are computed analytically based on Hartree-Fock theory with a complex absorbing potential. Ab initioAb\ initio molecular dynamics simulations for the temporary anions of dinitrogen, ethylene, chloroethane, and the five mono- to tetrachlorinated ethylenes show qualitative agreement with experiments and offer mechanistic insights into dissociative electron attachments. The results also demonstrate how our method evenhandedly deals with molecules that may undergo dissociation upon electron attachment and those which only undergo autodetachment.Comment: Manuscript: 10 pages, 4 figures. Supplementary Material: 41 pages, 43 figure

    Global navigation satellite system (GNSS): a utility for sustainable development in Ghana

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    The rapid spread of modern information and communication technologies (ICT) is dependent on the unprecedented increase in information relating to our natural, economic and social environment, and for Ghana and Africa to be in tune with the current trends in ICT, spatial information and methods to acquire them should be our priority. GNSS is therefore the obvious choice. This technology has an enormous potential to contribute to the management of environment, natural disasters, provide food security, emergency response, improve the efficiency in surveying and mapping. Land, water and air navigation will undergo a dramatic improvement with the application of GNSS. This is just to mention a few of the expected benefits. This paper focuses on the benefits to be derived by Ghana as a developing country and Africa in general from the introduction of a functional Multipurpose Global Navigation Satellite System. It specifically highlights the needed basic infrastructure for setting up a Continuously Operating reference System and the need for acquiring the necessary infrastructure to utilize the European Satellite-Based Augmentation System (SBAS), EGNOS. Areas of probable application and benefits have been outlined and the necessary considerations for a successful implementation and its sustenance have been suggested. It looks at how this space technology can support our sustainable development as developing nations.Journal of Science and Technology (Ghana) Vol. 27 (2) 2007: pp. 130-13

    Forecast of Future Aviation Fuels. Part 1: Scenarios

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    A preliminary set of scenarios is described for depicting the air transport industry as it grows and changes, up to the year 2025. This provides the background for predicting the needs for future aviation fuels to meet the requirements of the industry as new basic sources, such as oil shale and coal, which are utilized to supplement petroleum. Five scenarios are written to encompass a range of futures from a serious resource-constrained economy to a continuous and optimistic economic growth. A unique feature is the choice of one immediate range scenario which is based on a serious interruption of economic growth occasioned by an energy shortfall. This is presumed to occur due to lags in starting a synfuels program

    Using GIS for spatial exploratory analysis of borehole data: a firsthand approach towards groundwater development

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    Groundwater is an inimitable resource that provides water to communities especially in arid and semi-arid regions. However, the spatial variability of the resource as well as the heterogeneity and complex nature of aquifer systems that store groundwater presents difficulties for groundwater development. Thus, understanding the spatial structure of aquifer characteristics could be used as a resourceful tool and as a first point of call towards groundwater development. The study investigated aquifer characteristics particularly on transmissivity and specific capacity to determine how aquifer characteristics could be used in making predictions for new sites that need to be identified for potential groundwater development. Prediction maps were developed for transmissivity and specific capacity using ordinary kriging J-Bessel and exponential semi variograms techniques. The study revealed that 28% of the study area had high potential for groundwater development with transmissivity ranges of 34.40 – 46.52 m2/d. Equally, viable areas of 16% and 20% were identified with transmissivities of 27.99 – 34.39 m2/d and 13.07 – 19.47 m2/d respectively. Based on specific capacity, 21% of the study area was identified to have groundwater development potential with corresponding specific capacity of 13.54 – 20.7 m2/d. Similarly, 24% and 34% of the study area were also identified to be good for the exploitation of groundwater with corresponding specific capacities of 8.74 – 13.55 m2/d and 5.52 – 8.74 m2/d respectively. In terms of spatial structure, transmissivity was found to be variable compared to specific capacity. The application of Geographic Information Systems (GIS) is thus considered to be an immeasurable tool that could be used in mapping aquifer characteristics that can serve as firsthand information for groundwater development.Keywords: Spatial, Groundwater, Transmissivity, Specific capacity, Kriging, Semivariogram        

    An evaluation of the benefits and harms of antenatal corticosteroid treatment for women at risk of imminent preterm birth or prior to elective Caesarean-section: an individual participant data meta-analysis.:Study protocol

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    Background: Antenatal corticosteroid treatment (ACT) has been widely accepted as a safe, beneficial treatment which improves outcomes following preterm birth. It has been shown to reduce respiratory distress syndrome and neonatal mortality and is commonly used in threatened or planned preterm delivery, as well as prior to elective Caesarean-section at term. There are some concerns however, that in some cases, ACT is used in patients where clinical benefit has not been established, or may potentially increase harm. Many women who receive ACT do not deliver preterm and the long-term consequences of ACT treatment are unclear. This study aims to evaluate the benefits and harms of ACT using latest trial evidence to allow refinement of current practice. Methods: This study will compare ACT with placebo or non-treatment. Inclusion criteria are: Randomised Controlled Trials (RCT) comparing ACT vs. no ACT (with or without placebo) in all settings. Exclusion criteria are: non-randomised or quasi-randomised studies and studies comparing single vs. multiple courses of ACT. Main outcomes are to evaluate, for women at risk of preterm birth or undergoing planned Caesarean- section, the benefits and harms of ACT, on maternal, fetal, newborn, and long-term offspring health outcomes. The individual participant data (IPD) of identified RCTs will be collected and consecutively synthesised using meta-analysis with both a one-stage model where all IPD is analysed together and a two-stage model where treatment effect estimates are calculated for each trial individually first and thereafter pooled in a meta-analysis. Sub-group analysis will be performed to identify heterogeneous effects of ACT across predefined risk groups. Discussion: Co-opt is the Consortium for the Study of Pregnancy Treatments and aims to complete a robust evaluation of the benefits and harms of ACT. This IPD meta-analysis will contribute to this by allowing detailed interrogation of existing trial datasets. PROSPERO registration: CRD42020167312 (03/02/2020

    Femur-Sparing Pattern of Abnormal Fetal Growth in Pregnant Women from New York City After Maternal Zika Virus Infection

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    BACKGROUND: Zika virus (ZIKV) is a mosquito-transmitted flavivirus, which can induce fetal brain injury and growth restriction following maternal infection during pregnancy. Prenatal diagnosis of ZIKV-associated fetal injury in the absence of microcephaly is challenging due to an incomplete understanding of how maternal ZIKV infection affects fetal growth and the use of different sonographic reference standards around the world. We hypothesized that skeletal growth is unaffected by ZIKV infection and that the femur length can represent an internal standard to detect growth deceleration of the fetal head and/or abdomen by ultrasound. OBJECTIVE: To determine if maternal ZIKV infection is associated with a femur-sparing pattern of intrauterine growth restriction (IUGR) through analysis of fetal biometric measures and/or body ratios using the INTERGROWTH-21st Project (IG-21) and World Health Organization Fetal Growth Chart (WHO-FGC) sonographic references. STUDY DESIGN: Pregnant women diagnosed with a possible recent ZIKV infection at Columbia University Medical Center after traveling to an endemic area were retrospectively identified and included if a fetal ultrasound was performed. Data was collected regarding ZIKV testing, fetal biometry, pregnancy and neonatal outcomes. The IG-21 and WHO-FGC sonographic standards were applied to obtain Z-scores and/or percentiles for fetal head, abdominal circumference (HC, AC) and femur length (FL) specific for each gestational week. A novel IG-21 standard was also developed to generate Z-scores for fetal body ratios with respect to femur length (HC:FL, AC:FL). Data was then grouped within clinically relevant gestational age strata (34 weeks) to analyze time-dependent effects of ZIKV infection on fetal size. Statistical analysis was performed using Wilcoxon signed-rank test on paired data, comparing either AC or HC to FL. RESULTS: A total of 56 pregnant women were included in the study with laboratory evidence of a confirmed or possible recent ZIKV infection. Based on the CDC definition for microcephaly after congenital ZIKV exposure, microcephaly was diagnosed in 5% (3/56) by both the IG-21 and WHO-FGC standards (HC Z-score ≤ -2 or ≤ 2.3%). Using IG-21, IUGR was diagnosed in 18% of pregnancies (10/56; AC Z-score ≤-1.3, <10%). Analysis of fetal size using the last ultrasound scan for all subjects revealed a significantly abnormal skewing of fetal biometrics with a smaller AC versus FL by either IG-21 or WHO-FGC (p<0.001 for both). A difference in distribution of fetal AC compared to FL was first apparent in the 24-27 6/7 week strata (IG-21, p=0.002; WHO-FGC, p=0.001). A significantly smaller HC compared to FL was also observed by IG-21 as early as the 28-33 6/7 week strata (IG-21, p=0.007). Overall, a femur-sparing pattern of growth restriction was detected in 52% of pregnancies with either an HC:FL or AC:FL fetal body ratio less than the 10th percentile (IG-21 Z-score ≤-1.3). CONCLUSIONS: An unusual femur-sparing pattern of fetal growth restriction was detected in the majority of fetuses with congenital ZIKV exposure. Fetal body ratios may represent a more sensitive ultrasound biomarker to detect viral injury in nonmicrocephalic fetuses that could impart long-term risk for complications of congenital ZIKV infection

    Prenatal and perinatal determinants of lung health and disease in early life: A national heart, lung, and blood institute workshop report

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    Human lung growth and development begins with preconception exposures and continues through conception and childhood into early adulthood. Numerous environmental exposures (both positive and negative) can affect lung health and disease throughout life. Infant lung health correlates with adult lung function, but significant knowledge gaps exist regarding the influence of preconception, perinatal, and postnatal exposures on general lung health throughout life. On October 1 and 2, 2015, the National Heart, Lung, and Blood Institute convened a group of extramural investigators to develop their recommendations for the direction(s) for future research in prenatal and perinatal determinants of lung health and disease in early life and to identify opportunities for scientific advancement. They identified that future investigations will need not only to examine abnormal lung development, but also to use developing technology and resources to better define normal and/or enhanced lung health. Birth cohort studies offer key opportunities to capture the important influence of preconception and obstetric risk factors on lung health, development, and disease. These studies should include well-characterized obstetrical data and comprehensive plans for prospective follow-up. The importance of continued basic science, translational, and animal studies for providing mechanisms to explain causality using new methods cannot be overemphasized. Multidisciplinary approaches involving obstetricians, neonatologists, pediatric and adult pulmonologists, and basic scientists should be encouraged to design and conduct comprehensive and impactful research on the early stages of normal and abnormal human lung growth that influence adult outcome

    Cocoa seed multiplication: an assessment of seed gardens in Cameroon, Ghana and Nigeria

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    Adatoms and clusters of 3d transition metals on graphene: Electronic and magnetic configurations

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    We investigate the electronic and magnetic properties of single Fe, Co, and Ni atoms and clusters on monolayer graphene (MLG) on SiC(0001) by means of scanning tunneling microscopy (STM), x-ray absorption spectroscopy, x-ray magnetic circular dichroism (XMCD), and ab initio calculations. STM reveals different adsorption sites for Ni and Co adatoms. XMCD proves Fe and Co adatoms to be paramagnetic and to exhibit an out-of-plane easy axis in agreement with theory. In contrast, we experimentally find a nonmagnetic ground state for Ni monomers while an increasing cluster size leads to sizeable magnetic moments. These observations are well reproduced by our calculations and reveal the importance of hybridization effects and intra-atomic charge transfer for the properties of adatoms and clusters on MLG.Comment: 8 pages (supplementary included), 4 figures, (supplementary included
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