Trace Elements in Soils of the South Texas Uranium District: Concentrations, Origin, and Environmental Significance

UT Librarie

On a common circle: natural scenes and Gestalt rules

To understand how the human visual system analyzes images, it is essential to know the structure of the visual environment. In particular, natural images display consistent statistical properties that distinguish them from random luminance distributions. We have studied the geometric regularities of oriented elements (edges or line segments) present in an ensemble of visual scenes, asking how much information the presence of a segment in a particular location of the visual scene carries about the presence of a second segment at different relative positions and orientations. We observed strong long-range correlations in the distribution of oriented segments that extend over the whole visual field. We further show that a very simple geometric rule, cocircularity, predicts the arrangement of segments in natural scenes, and that different geometrical arrangements show relevant differences in their scaling properties. Our results show similarities to geometric features of previous physiological and psychophysical studies. We discuss the implications of these findings for theories of early vision.Comment: 3 figures, 2 large figures not include

News and narratives in financial systems: Exploiting big data for systemic risk assessment

This paper applies algorithmic analysis to financial market text-based data to assess how narratives and sentiment might drive financial system developments. We find changes in emotional content in narratives are highly correlated across data sources and show the formation (and subsequent collapse) of exuberance prior to the global financial crisis. Our metrics also have predictive power for other commonly used indicators of sentiment and appear to influence economic variables. A novel machine learning application also points towards increasing consensus around the strongly positive narrative prior to the crisis. Together, our metrics might help to warn about impending financial system distress

Study of maternal and perinatal outcome of referred patients in tertiary health centre

Background: Referral services for identification and referral of high risk pregnancies are an integral part of maternal and child health services. The aim of this study was to review the pattern of obstetric cases referred to tertiary care center, to identify their clinical course, mode of delivery, maternal and perinatal outcomes.Methods: It is a prospective observational study carried out from January 2017 to July 2017. Study population was all Obstetrics patients referred to Department of Obstetrics and Gynecology of B.J Medical College, Ahmedabad, Gujarat, India a tertiary care center during the study period.Results: The total number of referred cases in above study period was 100. Mode of transport used by the referred patients was by 108 ambulances (75%) and private vehicles (25%). Most common diagnosis at the time of referral was hypertensive disorders of pregnancy (31%). Out of the total referred cases, 57% had vaginal delivery, 42% had caesarean section. Hypertensive disorders of pregnancy constitute the leading cause of maternal deaths amongst the referred cases.Conclusions: The present study has shown that inadequate antenatal and intra-natal care at the periphery level is responsible for increased maternal and perinatal morbidity and mortality. Even today, hypertensive disorders of pregnancy are the leading cause of maternal mortality. Health education to the community will definitely reduce maternal and perinatal morbidity and mortality

Maternal mortality: a tertiary centre panic

Background: Maternal death has a serious implication on the family, society and nation. The preventable and avoidable factors have been noted in most of the maternal deaths and these can be reduced by effective and affordable actions. The objective of present study was to evaluate the causes of maternal mortality in a tertiary care hospital, assess its epidemiological aspects and suggest remedial measures to reduce the same.Methods: A retrospective study of all hospital records and death summaries of all maternal deaths over a period of 16 months from April 2015 to July 2016 was carried out and epidemiological factors and causes affecting maternal mortality were assessed.Results: A total of 100 maternal deaths occurred over a period of 15 months out of which unbooked and late referrals constituted 75.55 % of maternal deaths. Most maternal deaths occurred in the age group of 20–30 years, multiparous women (73%) and women from rural areas (71.%). Direct obstetric causes were responsible for 91 maternal deaths whereas 50 maternal deaths were due to indirect causes. Most common cause of death (41) was hemorrhage, followed by pregnancy-induced hypertension including eclampsia (15) and sepsis (21).Conclusions: Hemorrhage, sepsis and hypertension including eclampsia were seen as the direct major causes of death. There is a wide scope of improvement because a large proportion of the observed deaths are preventable

Trace and Potentially Toxic Elements Associated With Uranium Deposits in South Texas

The environmentally sensitive trace elements molybdenum, arsenic, and selenium are concentrated with uranium in ore deposits inSouth Texas. Cattle grazing in some pastures in mining areas have contracted molybdenosis, a cattle disease resulting from an imbalance of molybdenum and copper. To determine natural concentrations of the elements in soils in the South Texas area and to evaluate possible effects of mining on adjacent agricultural land, two sets of soil samples were collected and analyzed for molybdenum, arsenic, selenium, and copper. Two hundred and fifty-six samples were collected in a statistically random design from soils developed on the Whitsett Formation, Catahoula Formation, or Oakville Sandstone, the major uranium hosts of the area, and 182 samples were collected nonrandomly from areas of mining or mineralization to test specific hypotheses concerning the presence and origin of anomalously high concentrations of the elements. Results of the random sampling show that the different geologic formations have different characteristic trace element concentrations. The Whitsett Formation has higher molybdenum (resulting from minor near-surface mineralization) and lower copper concentrations than the other two formations. With the exception of molybdenum in the Whitsett Formation and copper in all three formations, the trace element concentrations are similar to published average concentrations in soils worldwide. Sampling in areas of mining and mineralization indicates that high concentrations of molybdenum, arsenic, or selenium occur dominantly in two situations: (1) in areas of shallow mineralization, resulting from natural processes and (2) in drainages adjacent to older abandoned mines, resulting from runoff from the mines. Moderately high concentrations also occur in a few reclaimed areas. Windblown dust from mining areas has not measurably affected trace element concentrations in adjacent areas. Comparison of molybdenum and copper concentrations in soils and grasses and theoretical considerations of the availability to plants of molybdenum and copper in soils suggest that forage in much of the area studied could have anomalously low copper/molybdenum ratios—low enough to induce molybdenosis in cattle. This report was submitted in fulfillment of Grant No. R804616-01-0 by the Bureau of Economic Geology, The University of Texas at Austin, under the sponsorship of the U.S. Environmental Protection Agency. This report covers the period April 1977 to April 1979, and work was completed as of August 31, 1978.Bureau of Economic Geolog

Dynamic Search on the GPU

Path finding is a fundamental, yet computationally expensive problem in robotics navigation. Often times, it is necessary to sacrifice optimality to find a feasible plan given a time constraint due to the search complexity. Dynamic environments may further invalidate current computed plans, requiring an efficient planning strategy that can repair existing solutions. This paper presents a massively parallelized wavefront-based approach to path planning, running on the GPU, that can efficiently repair plans to accommodate world changes and agent movement, without having to restart the wavefront propagation process. In addition, we introduce a termination condition which ensures the minimum number of GPU iterations while maintaining strict optimality constraints on search graphs with non-uniform costs