658 research outputs found

    Ground penetrating radar technique to locate coal mining related features: case studies in Texas

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    The goal of this research project is to identify the efficacy of the ground penetrating radar (GPR) technique in locating underground coal mine related subsidence features at Malakoff and Bastrop, Texas. The work at Malakoff has been done in collaboration with the Railroad Commission of Texas (RRC). RRC has been carrying out reclamation of abandoned underground coal mines at Malakoff since the early 1990Âs. The history of the specific mining operations (at Malakoff and Bastrop) that took place in the early 1900Âs has been difficult to ascertain; therefore, the use of a geophysical techniques like ground penetrating radar to identify hidden voids and potential subsidence features is vital for future reclamation process. Some of the underground mine workings at the field site have collapsed over time affecting the topography by creating sinkholes. GPR data, employing 25 MHz, 50 MHz and 100 MHz frequency antennae, have been collected in common offset patterns and azimuthal pattern. GPR data indicate the mine tunnels possibly connecting existing sinkholes by radargram hyperbolae that correspond with mine openings observed visually or during reclamation. This study also denotes the importance of understanding the variable physical properties of the stratigraphy, which could lead to false alarms by misinterpretation of the radar signals. Natural and man-made above-ground structures cause obstructions in data collection, and hence an optimal design is required for each survey. RRC successfully ground-truthed the data during its reclamation process. In turn, the acquired geophysical data helped to guide the reclamation. At Bastrop, GPR data along with historical documentation led to the conclusion that coal mining did exist in this region but is not a major concern to the immediate stability and safety of the field site. It can be concluded from both the studies that the GPR technique identifies anomalous shafts/tunnels possibly connecting potential failure

    Ground penetrating radar technique to locate coal mining related features: case studies in Texas

    Get PDF
    The goal of this research project is to identify the efficacy of the ground penetrating radar (GPR) technique in locating underground coal mine related subsidence features at Malakoff and Bastrop, Texas. The work at Malakoff has been done in collaboration with the Railroad Commission of Texas (RRC). RRC has been carrying out reclamation of abandoned underground coal mines at Malakoff since the early 1990Âs. The history of the specific mining operations (at Malakoff and Bastrop) that took place in the early 1900Âs has been difficult to ascertain; therefore, the use of a geophysical techniques like ground penetrating radar to identify hidden voids and potential subsidence features is vital for future reclamation process. Some of the underground mine workings at the field site have collapsed over time affecting the topography by creating sinkholes. GPR data, employing 25 MHz, 50 MHz and 100 MHz frequency antennae, have been collected in common offset patterns and azimuthal pattern. GPR data indicate the mine tunnels possibly connecting existing sinkholes by radargram hyperbolae that correspond with mine openings observed visually or during reclamation. This study also denotes the importance of understanding the variable physical properties of the stratigraphy, which could lead to false alarms by misinterpretation of the radar signals. Natural and man-made above-ground structures cause obstructions in data collection, and hence an optimal design is required for each survey. RRC successfully ground-truthed the data during its reclamation process. In turn, the acquired geophysical data helped to guide the reclamation. At Bastrop, GPR data along with historical documentation led to the conclusion that coal mining did exist in this region but is not a major concern to the immediate stability and safety of the field site. It can be concluded from both the studies that the GPR technique identifies anomalous shafts/tunnels possibly connecting potential failure

    Resilience and well-being among children of migrant parents in South-East Asia

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    There has been little systematic empirical research on the well-being of children in transnational households in South-East Asia—a major sending region for contract migrants. This study uses survey data collected in 2008 from children aged 9, 10 and 11 and their caregivers in Indonesia, the Philippines, and Vietnam (N=1,498). Results indicate that while children of migrant parents, especially migrant mothers, are less likely to be happy compared to children in non-migrant households, greater resilience in child well-being is associated with longer durations of maternal absence. There is no evidence for a direct parental migration effect on school enjoyment and performance. The analyses highlight the sensitivity of results to the dimension of child well-being measured and who makes the assessment.Publisher PDFPeer reviewe

    Preliminary assessment of economic sustainability of water supply schemes in rural highlands of Oromia

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    The study consists in a preliminary analysis about the economic sustainability of rural water supply schemes management in the highlands of Oromia region and it aims at providing the WaSH sector in Ethiopia with a methodology for reviewing tariffs and post-project management. A quantitative analysis is carried out through the Average Incremental Cost method and by assessing the Break-Even Point achievement of a stratified sample of water schemes, respectively considering: O&M, Depreciation and Capital Investment Return. Despite the limited sample dimension, the methodology has been proven consistent with the challenging situation of the rural water supply sustainability. Hence the study offers relevant findings and reflections on the fragile link between tariff setting and cost-recovery necessities and the implications of low economic sustainability, which is often the main cause of water schemes malfunctioning. Finally, a more comprehensive investigation on the same theme across the sector in Ethiopia is suggested

    GRACE satellite monitoring of large depletion in water storage in response to the 2011 drought in Texas

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    International audienceTexas experienced the most extreme one-year drought on record in 2011 with precipitation at 40% of long-term mean and agricultural losses of ~$7.6 billion. We assess the value of Gravity Recovery and Climate Experiment (GRACE) satellite-derived total water storage (TWS) change as an alternative remote sensing-based drought indicator, independent of traditional drought indicators based on in situ monitoring. GRACE shows depletion in TWS of 62.3 ± 17.7 km3 during the 2011 drought. Large uncertainties in simulated soil moisture storage depletion (14-83 km3) from six land surface models indicate that GRACE TWS is a more reliable drought indicator than disaggregated soil moisture or groundwater storage. Groundwater use and groundwater level data indicate that depletion is dominated by changes in soil moisture storage, consistent with high correlation between GRACE TWS and the Palmer Drought Severity Index. GRACE provides a valuable tool for monitoring statewide water storage depletion, linking meteorological and hydrological droughts

    Locating the place and meaning of physical activity in the lives of young people from low-income, lone-parent families

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    Background: In the United Kingdom (UK), it is predicted that economic cuts and a subsequent increase in child poverty will affect those already on the lowest incomes and, in particular, those living in lone-parent families. As a result, the informal pedagogic encounters within the family that contribute to the development of physical activity-related values, beliefs and dispositions from a very early age will be affected. Therefore, it is vital that we gain an understanding of the place and meaning of physical activity in the lives of young people, as well as the informal pedagogic practices and the socio-cultural forces that influence individual agency. Purpose: Based on Bourdieu's key concepts, this paper explores the interplay of structural conditions and personal agency with regard to physical activity in the lives of young people from low-income, lone-parent families. Methods: This study reports on the voices of 24 participants (aged 11–14) from low-income, lone-parent families in the West Midlands, UK. These participants were engaged in paired, semi-structured interviews to explore issues of personal agency by listening to how they reported on their present lives, past experiences and future possibilities with regard to physical activity. All corresponding interview data were analysed using analytical induction. Findings: This paper suggests that young people exhibited diminished desires to engage in activity due to structural constraints of time, parents' work commitments and a lack of transport that resulted in engagement in sedentary alternatives. Informal pedagogic practices within these families were restricted due to the associated structural conditions of living in a lone-parent family. As such, young people's choice to not seek out physical activities when at home reflected a ‘taste for necessity’ resulting from a lack of cultural and economic capital, placing restrictions on physical activity opportunities that stemmed from their family doxa. Conclusions: To succeed in fostering dispositions and opportunities to participate in physical activity, we must engage with young people from low-income, lone-parent families from an early age. Certainly though, further consideration of the informal pedagogic practices within, and the demands on, lone-parent families is required when designing any intervention or policy that seeks to enhance their current circumstances and provide opportunities for engagement in a variety of contexts

    Effects of climate and irrigation on GRACE-based estimates of water storage changes in major US aquifers

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    Understanding climate and human impacts on water storage is critical for sustainable water-resources management. Here we assessed climate and human drivers of total water storage (TWS) variability from Gravity Recovery and Climate Experiment (GRACE) satellites compared with drought severity and irrigation water use in 14 major aquifers in the United States. Results show that long-term variability in TWS tracked by GRACE satellites is dominated by interannual variability in most of the 14 major US aquifers. Low TWS trends in the humid eastern U.S. are linked to low drought intensity. Although irrigation pumpage in the humid Mississippi Embayment aquifer exceeded that in the semi-arid California Central Valley, a surprising lack of TWS depletion in the Mississippi Embayment aquifer is attributed to extensive streamflow capture. Marked storage depletion in the semi-arid southwestern Central Valley and south-central High Plains totaled ∌90 km ^3 , about three times greater than the capacity of Lake Mead, the largest U.S. reservoir. Depletion in the Central Valley was driven by long-term droughts (â©œ5 yr) amplified by switching from mostly surface water to groundwater irrigation. Low or slightly rising TWS trends in the northwestern (Columbia and Snake Basins) US are attributed to dampening drought impacts by mostly surface water irrigation. GRACE satellite data highlight synergies between climate and irrigation, resulting in little impact on TWS in the humid east, amplified TWS depletion in the semi-arid southwest and southcentral US, and dampened TWS deletion in the northwest and north central US Sustainable groundwater management benefits from conjunctive use of surface water and groundwater, inefficient surface water irrigation promoting groundwater recharge, efficient groundwater irrigation minimizing depletion, and increasing managed aquifer recharge. This study has important implications for sustainable water development in many regions globally

    Variants of Tribulus species – a scientific study through DNA RAPD – molecular characterization

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    Gokshura a well-known drug in Ayurveda which is extensively used in many disease conditions like dysuria, asthma, diabetes, cough, oedema, cardiac disorders etc. Tribulus terrestris (Family – Zygophyllaceae) is an official source of Gokshura as per API. Five species of genus Tribulus are found throughout India with a slight morphological difference. In this study, three different species of Tribulus genus from different regions were subjected for molecular characterization by RAPD method. Analysis showed that three different samples gave clearly similar banding pattern with each of the random primers used and 80% similarity between the three samples were observed when the results were subjected to band scoring and analysis with clustering. Even through the micromorpholgical observations showed differentiating characters in mature carpels and intrastaminal glands of the selected species

    Mood and anxiety disorders in very preterm/very low-birth weight individuals from 6 to 26 years

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    Background Very preterm (<32 weeks’ gestational age; VP) or very low–birth weight (<1,500 g; VLBW) birth has been associated with increased risk for anxiety and mood disorders and less partnering in adulthood. The aim was to test whether (a) VP/VLBW are at increased risk of any anxiety or mood disorders from 6 to 26 years compared with term-born individuals; (b) social support from romantic partners is associated with protection from anxiety and mood disorders; and (c) VP/VLBW adults’ lower social support mediates their risk for any anxiety and mood disorders. Methods Data are from a prospective geographically defined longitudinal whole-population study in South Bavaria (Germany). Two hundred VP/VLBW and 197 term individuals were studied from birth to adulthood. Anxiety and mood disorders were assessed at 6, 8, and 26 years with standardized diagnostic interviews and social support via self-report at age 26. Results At age 6, VP/VLBW children were not at increased risk of any anxiety or mood disorder. At age 8, VP/VLBW more often had any anxiety disorder than term comparisons (11.8% vs. 6.6%, OR = 2.10, 95% CI [1.08–4.10]). VP/VLBW adults had an increased risk for any mood (27.5% vs. 18.8%, OR = 1.65 [1.02–2.67]) but not for any anxiety disorder (33.0% vs. 28.4%, OR = 1.27 [0.82–1.96]). None of the significant differences survived correction for multiple testing. Social support was associated with a lower risk of anxiety or mood disorders in both groups (OR = 0.81 [0.68–0.96]) and mediated the association of VP/VLBW birth with any anxiety or any mood disorders at age 26. Conclusions This study does not show a persistently increased risk for any anxiety or mood disorder after VP/VLBW birth. Low social support from a romantic partner mediates the risk for anxiety or mood disorders after VP/VLBW birth

    Urinary ATP as an indicator of infection and inflammation of the urinary tract in patients with lower urinary tract symptoms

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    BACKGROUND: Adenosine-5'-triphosphate (ATP) is a neurotransmitter and inflammatory cytokine implicated in the pathophysiology of lower urinary tract disease. ATP additionally reflects microbial biomass thus has potential as a surrogate marker of urinary tract infection (UTI). The optimum clinical sampling method for ATP urinalysis has not been established. We tested the potential of urinary ATP in the assessment of lower urinary tract symptoms, infection and inflammation, and validated sampling methods for clinical practice. METHODS: A prospective, blinded, cross-sectional observational study of adult patients presenting with lower urinary tract symptoms (LUTS) and asymptomatic controls, was conducted between October 2009 and October 2012. Urinary ATP was assayed by a luciferin-luciferase method, pyuria counted by microscopy of fresh unspun urine and symptoms assessed using validated questionnaires. The sample collection, storage and processing methods were also validated. RESULTS: 75 controls and 340 patients with LUTS were grouped as without pyuria (n = 100), pyuria 1-9 wbc ?l(-1) (n = 120) and pyuria ?10 wbc ?l(-1) (n = 120). Urinary ATP was higher in association with female gender, voiding symptoms, pyuria greater than 10 wbc ?l(-1) and negative MSU culture. ROC curve analysis showed no evidence of diagnostic test potential. The urinary ATP signal decayed with storage at 23°C but was prevented by immediate freezing at ??-20°C, without boric acid preservative and without the need to centrifuge urine prior to freezing. CONCLUSIONS: Urinary ATP may have a role as a research tool but is unconvincing as a surrogate, clinical diagnostic marker
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