Volcanic architecture of the Deccan Traps, western Maharashtra, India: an integrated chemostratigraphic and paleomagnetic study

Detailed volcanostratigraphic logs of seven traverses up the lava sequence in the Western Ghats, Deccan Traps, India, are presented. The main study area, the Mahabaleshwar Plateau, was chosen because the lavas were emplaced around the time of the Cretaceous-Tertiary Boundary and because there is access to exposed lavas on three of its four sides, permitting investigation of the volcanic architecture in 3-D. Besides characteristics of the lava units, the logs include integrated geochemical and palaeomagnetic samples. The lava pile is dominated by pthoehoe sheet lobes and smaller lobes and toes. It can be divided into flow-fields, the products of one eruption, by the occurrence of weathering horizons. Palaeomagnetic results demonstrate that the chron 29R/29N reversal boundary horizon occurs in all four of the traverses around the Plateau and nearby Khumbarli Ghat. The elevation of the reversal horizon on each traverse varies between 897-945 m and 982 m, a value greater than that predicted by the small regional dip. Statistical analysis of geochemical data from samples taken between the reversal horizon and the base of the Mahabaleshwar Formation do not show any apparent correlation around the Mahabaleshwar Plateau, indicating that individual sheet lobes are less than 20 km wide. Determining the lateral extent of flow-fields is not possible using this method but from the occurrence of a similar number of flow-fields in three traverses of similar length round the Plateau, it is probable that most flow fields are at least as wide as the Mahabaleshwar Plateau (more than 20 km). Comparing the thickness of the lava pile between the base of the Mahabaleshwar Formation, the palaeomagnetic reversal horizon and the laterite cap, shows that as much as 95m of topography occurred on the surface of the active Deccan lavas over a distance of approximately 20 km. The volcanic architecture is controlled by the morphology of small sheet lobes, large sheet lobes, and, on a larger scale, flow-fields. These observations, and the varying number of individual sheet lobes making up flow-fields, demonstrates that the structure of the Deccan lava province at the level of eruptive units is extremely complex

Opportunities to reduce overuse of antibiotics for perinatal group B streptococcal disease prevention and management of preterm premature rupture of membranes.

OBJECTIVE: To identify opportunities to reduce overuse of antibiotics for prevention of perinatal group B streptococcal (GBS) disease and management of preterm premature rupture of membranes (pPROM). METHODS: An anonymous written questionnaire was sent to each of 1031 Fellows of the American College of Obstetricians and Gynecologists, and the responses were subjected to statistical analysis. RESULTS: Among those of the 404 respondents who saw obstetric patients in 2001, most (84%) screened for GBS colonization, and 22% of these prescribed prenatal antibiotics to try to eradicate GBS colonization. Of the 382 respondents (95%) who prescribed antibiotics for pPROM, 36% continued antibiotics for more than 7 days despite negative results from GBS cultures collected before initiation of treatment. Having more years of clinical experience (adjusted odds ratio (OR) 3.0, 95% confidence interval (CI) 1.5 to 6.2), working in a non-academic setting (adjusted OR 2.7, 95% CI 1.0 to 6.9), and prescribing antibiotics prenatally for GBS colonization (adjusted OR 2.0, 95% CI 1.1 to 3.4) were associated with prescribing prolonged antibiotics for pPROM. CONCLUSION: Prenatal antibiotic treatment for GBS colonization and prolonged antibiotic treatment for pPROM contribute to overuse of antibiotics in obstetrics

Effects of local meteorology and aerosols on ozone and nitrogen dioxide retrievals from OMI and pandora spectrometers in Maryland, USA during DISCOVER-AQ 2011

An analysis is presented for both ground- and satellite-based retrievals of total column ozone and nitrogen dioxide levels from the Washington, D.C., and Baltimore, Maryland, metropolitan area during the NASA-sponsored July 2011 campaign of Deriving Information on Surface COnditions from Column and VERtically Resolved Observations Relevant to Air Quality (DISCOVER-AQ). Satellite retrievals of total column ozone and nitrogen dioxide from the Ozone Monitoring Instrument (OMI) on the Aura satellite are used, while Pandora spectrometers provide total column ozone and nitrogen dioxide amounts from the ground. We found that OMI and Pandora agree well (residuals within ±25 % for nitrogen dioxide, and ±4.5 % for ozone) for a majority of coincident observations during July 2011. Comparisons with surface nitrogen dioxide from a Teledyne API 200 EU NOx Analyzer showed nitrogen dioxide diurnal variability that was consistent with measurements by Pandora. However, the wide OMI field of view, clouds, and aerosols affected retrievals on certain days, resulting in differences between Pandora and OMI of up to ±65 % for total column nitrogen dioxide, and ±23 % for total column ozone. As expected, significant cloud cover (cloud fraction \u3e0.2) was the most important parameter affecting comparisons of ozone retrievals; however, small, passing cumulus clouds that do not coincide with a high (\u3e0.2) cloud fraction, or low aerosol layers which cause significant backscatter near the ground affected the comparisons of total column nitrogen dioxide retrievals. Our results will impact post-processing satellite retrieval algorithms and quality control procedures

Estimating Water Supply Arsenic Levels in the New England Bladder Cancer Study

Background: Ingestion of inorganic arsenic in drinking water is recognized as a cause of bladder cancer when levels are relatively high (≥ 150 µg/L). The epidemiologic evidence is less clear at the low-to-moderate concentrations typically observed in the United States. Accurate retrospective exposure assessment over a long time period is a major challenge in conducting epidemiologic studies of environmental factors and diseases with long latency, such as cancer. Objective: We estimated arsenic concentrations in the water supplies of 2,611 participants in a population-based case–control study in northern New England. Methods: Estimates covered the lifetimes of most study participants and were based on a combination of arsenic measurements at the homes of the participants and statistical modeling of arsenic concentrations in the water supply of both past and current homes. We assigned a residential water supply arsenic concentration for 165,138 (95%) of the total 173,361 lifetime exposure years (EYs) and a workplace water supply arsenic level for 85,195 EYs (86% of reported occupational years). Results: Three methods accounted for 93% of the residential estimates of arsenic concentration: direct measurement of water samples (27%; median, 0.3 µg/L; range, 0.1–11.5), statistical models of water utility measurement data (49%; median, 0.4 µg/L; range, 0.3–3.3), and statistical models of arsenic concentrations in wells using aquifers in New England (17%; median, 1.6 µg/L; range, 0.6–22.4). Conclusions: We used a different validation procedure for each of the three methods, and found our estimated levels to be comparable with available measured concentrations. This methodology allowed us to calculate potential drinking water exposure over long periods

Inactivation of a Novel FGF23 Regulator, FAM20C, Leads to Hypophosphatemic Rickets in Mice

Family with sequence similarity 20,-member C (FAM20C) is highly expressed in the mineralized tissues of mammals. Genetic studies showed that the loss-of-function mutations in FAM20C were associated with human lethal osteosclerotic bone dysplasia (Raine Syndrome), implying an inhibitory role of this molecule in bone formation. However, in vitro gain- and loss-of-function studies suggested that FAM20C promotes the differentiation and mineralization of mouse mesenchymal cells and odontoblasts. Recently, we generated Fam20c conditional knockout (cKO) mice in which Fam20c was globally inactivated (by crossbreeding with Sox2-Cre mice) or inactivated specifically in the mineralized tissues (by crossbreeding with 3.6 kb Col 1a1-Cre mice). Fam20c transgenic mice were also generated and crossbred with Fam20c cKO mice to introduce the transgene in the knockout background. In vitro gain- and loss-of-function were examined by adding recombinant FAM20C to MC3T3-E1 cells and by lentiviral shRNA–mediated knockdown of FAM20C in human and mouse osteogenic cell lines. Surprisingly, both the global and mineralized tissue-specific cKO mice developed hypophosphatemic rickets (but not osteosclerosis), along with a significant downregulation of osteoblast differentiation markers and a dramatic elevation of fibroblast growth factor 23 (FGF23) in the serum and bone. The mice expressing the Fam20c transgene in the wild-type background showed no abnormalities, while the expression of the Fam20c transgene fully rescued the skeletal defects in the cKO mice. Recombinant FAM20C promoted the differentiation and mineralization of MC3T3-E1 cells. Knockdown of FAM20C led to a remarkable downregulation of DMP1, along with a significant upregulation of FGF23 in both human and mouse osteogenic cell lines. These results indicate that FAM20C is a bone formation “promoter” but not an “inhibitor” in mouse osteogenesis. We conclude that FAM20C may regulate osteogenesis through its direct role in facilitating osteoblast differentiation and its systemic regulation of phosphate homeostasis via the mediation of FGF23

Perceived Everyday Racism, Residential Segregation, and HIV Testing Among Patients at a Sexually Transmitted Disease Clinic

Objectives. More than one quarter of HIV-infected people are undiagnosed and therefore unaware of their HIV-positive status. Blacks are disproportionately infected. Although perceived racism influences their attitudes toward HIV prevention, how racism influences their behaviors is unknown. We sought to determine whether perceiving everyday racism and racial segregation influence Black HIV testing behavior

Emplacement of inflated Pāhoehoe flows in the Naude’s Nek Pass, Lesotho remnant, Karoo continental flood basalt province: use of flow-lobe tumuli in understanding flood basalt emplacement

Physical volcanological features are presented for a 710-m-thick section, of the Naude’s Nek Pass, within the lower part of the Lesotho remnant of the Karoo Large Igneous Province. The section consists of inflated pāhoehoe lava with thin, impersistent sedimentary interbeds towards the base. There are seven discreet packages of compound and hummocky pāhoehoe lobes containing flow-lobe tumuli, making up approximately 50% of the section. Approximately 45% of the sequence consists of 14 sheet lobes, between 10 and 52-m-thick. The majority of the sheet lobes are in two packages indicating prolonged periods of lava supply capable of producing thick sheet lobes. The other sheet lobes are as individual lobes or pairs, within compound flows, suggesting brief increases in lava supply rate. We suggest, contrary to current belief, that there is no evidence that compound flows are proximal to source and sheet lobes (simple flows) are distal to source and we propose that the presence of flow-lobe tumuli in compound flows could be an indicator that a flow is distal to source. We use detailed, previously published, studies of the Thakurvadi Formation (Deccan Traps) as an example. We show that the length of a lobe and therefore the sections that are ‘medial or distal to source’ are specific to each individual lobe and are dependent on the lava supply of each eruptive event, and as such flow lobe tumuli can be used as an indicator of relative distance from source

“What if There's Something Wrong with Her?”‐How Biomedical Technologies Contribute to Epistemic Injustice in Healthcare

While there is a steadily growing literature on epistemic injustice in healthcare, there are few discussions of the role that biomedical technologies play in harming patients in their capacity as knowers. Through an analysis of newborn and pediatric genetic and genomic sequencing technologies (GSTs), I argue that biomedical technologies can lead to epistemic injustice through two primary pathways: epistemic capture and value partitioning. I close by discussing the larger ethical and political context of critical analyses of GSTs and their broader implications for just and equitable healthcare delivery