Home About us Contact
|
Home About us Contact | ||
|
|
||
Similar Settings (similar + setting)
Selected AbstractsMultiple Sources of Metals of Mineralization in Lower Cambrian Black Shales of South China: Evidence from Geochemical and Petrographic StudyRESOURCE GEOLOGY, Issue 1 2008Jan Pa Abstract Black shales of the Lower Cambrian Niutitang Formation in southern China (Huangjiawan mine, Zunyi region, northern part of the Guizhou Province) host regionally distributed stratiform polymetallic Ni-Mo-platinum group elements (PGE)-Au phosphate- and sulfide-rich ores. These are confined to a ,0.2-m thick ore horizon composed of mineralized bodies of algal onkolites, phosphate nodules, and sulfide and shale clasts in a mineralized phosphate- and organic matter-rich matrix. Compared to footwall and hanging wall shales, the ore bed is strongly enriched in Ni (up to 100-fold), As (up to 97-fold), Mo (up to 95-fold), Sb (up to 67-fold), Rh (up to 49-fold), Cu (up to 37-fold), Pd (up to 33-fold), Ru (up to 24-fold), Zn (up to 23-fold), Pt (up to 21-fold), Ir (up to 15-fold), Co (up to 14-fold), and Pb (up to 13-fold). Even footwall and hanging wall black shales are significantly enriched by Mo (21-fold) and Ni (12-fold) but depleted in Cr in comparison to average Cambrian black shale. Organic matter is represented by separate accumulations dispersed in the rock matrix or as biotic bitumen droplets and veinlets in ore clasts. Similar organic carbon (Corg) values in an ore bed and enclosing footwall and hanging wall shales of little mineralization indicate that metal accumulation was not controlled only by biogenic productivity and organic matter accumulation rate. Evaporitic conditions during sedimentation of the basal part of the Niutitang Formation were documented by an occurrence of preserved Ni-, V-, Cr-, and Cu-enriched phosphate-rich hardground with halite and anhydrite pseudomorphs on the paleosurface of the underlying Neoproterozoic carbonates. Neoproterozoic black shales of the Doushantuo Formation are characterized by increased metal concentrations. Comparison of metal abundances in both hardground and Doushantuo black shales indicate that black shales could have become a source of metal-rich hardground during weathering. The polymetallic Ni-Mo-PGE sulfide-rich ore bed is interpreted to represent a remnant of shallow-water hardground horizon rich in metals, which originated in a sediment-starved, semi-restricted, seawater environment. During the Early Cambrian transgression an influx of fresh seawater and intensive evaporation, together with the hydrothermal enrichment of seawater in a semi-restricted basin, resulted in the formation of dense metalliferous brines; co-precipitation of metals together with phosphates and sulfides occurred at or above the oxic,anoxic sediment interface. Metal-enriched hardground was disintegrated by the action of waves or bottom currents and deposited in a deeper part of the anoxic basin. Contemporaneously with the formation of a polymetallic Ni-Mo-PGE-Au sulfide ore bed, economic sedimentary exhalative (SEDEX)-type barite deposits were forming in a stratigraphically and geotectonically similar setting. The results of geochemical study at the Shang Gongtang SEDEX-type Ba deposit indicate that concentrations of Ag, As, Cr, Cu, Fe, Mn, Ni, Pb, Sb, V, Zn and other metals decrease from top of the barite body toward the hanging wall black shale. Lower Cambrian black shales of the Niutitang Formation above the barite body also display similar element abundances as Neoproterozoic black shales of the Doushantuo Formation, developed in the footwall of the barite body. But the geochemical composition of the sulfide layer is different from the Ni-Mo ore bed, showing only elevated Pb, Cu, Ni and Mo values. It is suggested that hydrothermal brines at Shang Gongtang might have leached metals from footwall Neoproterozoic sequences and became, after mixing with normal seawater, an additional source of Ag, Cr, Cu, Pb, Sb, Zn, Ni, PGE, V and other metals. [source] From Model to Forecasting: A Multicenter Study in Emergency DepartmentsACADEMIC EMERGENCY MEDICINE, Issue 9 2010Mathias Wargon MD ACADEMIC EMERGENCY MEDICINE 2010; 17:970,978 © 2010 by the Society for Academic Emergency Medicine Abstract Objectives:, This study investigated whether mathematical models using calendar variables could identify the determinants of emergency department (ED) census over time in geographically close EDs and assessed the performance of long-term forecasts. Methods:, Daily visits in four EDs at academic hospitals in the Paris area were collected from 2004 to 2007. First, a general linear model (GLM) based on calendar variables was used to assess two consecutive periods of 2 years each to create and test the mathematical models. Second, 2007 ED attendance was forecasted, based on a training set of data from 2004 to 2006. These analyses were performed on data sets from each individual ED and in a virtual mega ED, grouping all of the visits. Models and forecast accuracy were evaluated by mean absolute percentage error (MAPE). Results:, The authors recorded 299,743 and 322,510 ED visits for the two periods, 2004,2005 and 2006,2007, respectively. The models accounted for up to 50% of the variations with a MAPE less than 10%. Visit patterns according to weekdays and holidays were different from one hospital to another, without seasonality. Influential factors changed over time within one ED, reducing the accuracy of forecasts. Forecasts led to a MAPE of 5.3% for the four EDs together and from 8.1% to 17.0% for each hospital. Conclusions:, Unexpectedly, in geographically close EDs over short periods of time, calendar determinants of attendance were different. In our setting, models and forecasts are more valuable to predict the combined ED attendance of several hospitals. In similar settings where resources are shared between facilities, these mathematical models could be a valuable tool to anticipate staff needs and site allocation. [source] Nursing diagnoses, interventions and outcomes , application and impact on nursing practice: systematic reviewJOURNAL OF ADVANCED NURSING, Issue 5 2006Maria Müller-Staub Head of Pflege PBS EdN MNS RN Aim., This paper reports a systematic review on the outcomes of nursing diagnostics. Specifically, it examines effects on documentation of assessment quality; frequency, accuracy and completeness of nursing diagnoses; and on coherence between nursing diagnoses, interventions and outcomes. Background., Escalating healthcare costs demand the measurement of nursing's contribution to care. Use of standardized terminologies facilitates this measurement. Although several studies have evaluated nursing diagnosis documentation and their relationship with interventions and outcomes, a systematic review has not been carried out. Method., A Medline, CINAHL, and Cochrane Database search (1982,2004) was conducted and enhanced by the addition of primary source and conference proceeding articles. Inclusion criteria were established and applied. Thirty-six articles were selected and subjected to thematic content analysis; each study was then assessed, and a level of evidence and grades of recommendations assigned. Findings., Nursing diagnosis use improved the quality of documented patient assessments (n = 14 studies), identification of commonly occurring diagnoses within similar settings (n = 10), and coherence among nursing diagnoses, interventions, and outcomes (n = 8). Four studies employed a continuing education intervention and found statistically significant improvements in the documentation of diagnoses, interventions and outcomes. However, limitations in diagnostic accuracy, reporting of signs/symptoms, and aetiology were also reported (14 studies). One meta-analysis of eight trials including 1497 patients showed no evidence that standardized electronic documentation of nursing diagnosis and related interventions led to better nursing outcomes. Conclusion., Despite variable results, the trend indicated that nursing diagnostics improved assessment documentation, the quality of interventions reported, and outcomes attained. The study reveals deficits in reporting of signs/symptoms and aetiology. Consequently, staff educational measures to enhance diagnostic accuracy are recommended. The relationships among diagnoses, interventions and outcomes require further evaluation. Studies are needed to determine the relationship between the quality of documentation and practice. [source] Southeast Alaska: oceanographic habitats and linkagesJOURNAL OF BIOGEOGRAPHY, Issue 3 2009Thomas Weingartner Abstract We provide an overview of the physical oceanographic and geological processes that affect marine biological habitats and production in the marine waters throughout the archipelago and continental shelf of Southeast Alaska. Given the paucity of regional data, our overview summarizes work done in adjacent regions of the Gulf of Alaska shelf and basin, and draws on research carried out in similar settings elsewhere. The geological setting, which critically influences the regional meteorology and oceanography, includes a narrow continental shelf, deep channels that permeate the archipelago, fjords, glaciers and a rugged, mountainous coast. The large-scale meteorology is influenced primarily by seasonal variations in the intensity and position of the Aleutian Low. Winds, freshwater runoff, tides and cross-shelf exchange control the regional oceanography. The large-scale flow field advects mass, heat, salt, nutrients and planktonic organisms northward from British Columbia (and even further south) to the northern Gulf of Alaska along the slope, shelf, and within the channels of Southeast Alaska. The deep channels permeating the island archipelago and narrow continental shelf facilitate communication between basin and interior waters. Water properties and flow fields are subject to large annual variations in response to similarly large variations in winds and coastal freshwater discharge. The complex geological setting leads to large spatial heterogeneity in the physical processes controlling the local circulation fields and mixing, thereby creating numerous and diverse marine biological habitats. These various circulation and mixing processes modify substantially Southeast Alaska water masses and thus influence marine ecosystem processes downstream over the northern and western Gulf of Alaska shelf. [source] Preparing for Motherhood: Authoritative Knowledge and the Undercurrents of Shared Experience in Two Childbirth Education Courses in Cagliari, ItalyMEDICAL ANTHROPOLOGY QUARTERLY, Issue 2 2000Suzanne K. Ketler This article compares the social settings and teaching organization of two differently structured childbirth education courses in Cagliari, Italy, in order to understand how social processes and contexts work to negotiate authoritative knowledge. Although the explicit goal of both courses was to transmit biomedical knowledge, knowledge based in women's experience nonetheless dominated some course sessions. Thus, I examine the social processes and interactions that enabled women's experiential knowledge to dominate discussions and subsequently share in the authority of biomedical knowledge in some situations. Because few existing studies do so, this article also addresses a gap in our current understanding by exploring not only how experiential knowledge comes to share authority with biomedical knowledge, but also, why it is important that it does. Focusing on the efficacy of differently structured courses, this article informs the planning of future childbirth education courses in similar settings, [childbirth education, authoritative knowledge, reproduction, prenatal care, Italy] [source] Estimation of a residual distribution with small numbers of repeated measurementsTHE CANADIAN JOURNAL OF STATISTICS, Issue 3 2002Edward Susko Abstract The authors consider the estimation of a residual distribution for different measurement problems with a common measurement error process. The problem is motivated by issues arising in the analysis of gene expression data but should have application in other similar settings. It is implicitly assumed throughout that there are large numbers of measurements but small numbers of repeated measurements. As a consequence, the distribution of the estimated residuals is a biased estimate of the residual distribution. The authors present two methods for the estimation of the residual distribution with some restriction on the form of the distribution. They give an upper bound for the rate of convergence for an estimator based on the characteristic function and compare its performance with that of another estimator with simulations. Estimation de la loi des erreurs à partir d'un petit nombre de mesures répétées Les auteurs s' intéressent à l' estimation d' une loi des erreurs supposée commune à un ensemble de situations expérimentales. Leur préoccupation émane de problèmes concernant l' analyse de l' expression des génes, mais la méthodologie qu' ils proposent a une portée plus large. Leur technique suppose l' accés à un grand nombre de données mais à un petit nombre de mesures répétées. La loi des résidus constitue alors un estimateur biaisé de celle des erreurs. Les auteurs présentent deux méthodes d' estimation de cette dernière, sous certaines hypothèses quant à sa forme. Us majorent le taux de convergence d' un premier estimateur dérivé de la fonction caractéristique et comparent sa performance à celle d' un second au moyen de simulations. [source] MICROFINANCE REVOLUTION: ITS EFFECTS, INNOVATIONS, AND CHALLENGESTHE DEVELOPING ECONOMIES, Issue 1 2010Hisaki KONO F35; O19 "Microfinance revolution" is the term often applied to the successful expansion of small-scale financial services to the poor with high repayment records in developing countries. The present paper investigates the extent to which the microfinance revolution is truly revolutionary. More specifically, it explores the impact of microfinance institutions on the poor, the mechanisms underlying high repayment rates and their innovations, and the new challenges microfinance institutions are currently facing. Different from the existing published survey literature, we focus on current topics and attempt to show recent theoretical developments in a comprehensive manner using simplified models with very similar settings. We contend that microfinance is developing in a promising direction but has yet to reach its full potential. [source] Managers' Active Support when Implementing Teams: The Impact on Employee Well-BeingAPPLIED PSYCHOLOGY: HEALTH AND WELL-BEING, Issue 3 2009Karina Nielsen Research has shown that a variety of organisational change interventions can be effective but the powerful positive results of an intervention do not always generalise to other similar settings. Problems with implementation and a difficult intervention context have been shown to undermine the effectiveness of promising interventions. The impact that middle managers have on the change process and intervention outcomes has not been widely researched. This longitudinal intervention study was carried out in the elderly care sector in a large Danish local government organisation (N = 188), where poor social support, and lack of role clarity and meaningful work had been identified as significant problems. To tackle these problems, teamwork was implemented, with teams having some degree of self-management. It examined whether middle managers' active support for the intervention mediated its impact on working conditions, well-being and job satisfaction. Structural equation modelling showed that middle managers' active involvement in implementing the change partially mediated the relationship between working conditions at time 1 and time 2. Working conditions at time 2 were in turn related to time 2 job satisfaction and well-being. These results suggest that the degree to which employees perceive their middle managers to play an active role in implementing change is related to intervention outcomes. [source] Household food security is associated with early childhood language development: results from a longitudinal study in rural BangladeshCHILD: CARE, HEALTH AND DEVELOPMENT, Issue 3 2010K. K. Saha Abstract Background Although household food security (HHFS) has been linked to academic performance in school children, its association with early childhood development has received less attention, particularly in low-income countries. We investigated the association of HHFS with subsequent language development of children at 18 months of age in rural Bangladesh. Methods We followed 1439 infants born in 2002,2003 to the mothers in Maternal and Infant Nutrition Intervention in Matlab study, a large intervention trial conducted in rural Bangladesh. A HHFS scale was created from data collected from mothers during pregnancy. At 18 months, children's language (expression and comprehension) development was assessed using a Bengali adaptation of MacArthur's Communicative Development Inventory which was based on mothers' report of their children's ability to comprehend and express words in different categories. General linear regression models were used to examine the association between HHFS and language development at 18 months of age adjusting for potential confounders. Results Household food security was associated with language comprehension (B = 0.19, 95% CI = 0.09, 0.30, P < 0.001) and expression (B = 1.01, 95% CI = 1.00, 1.02, P < 0.01) at 18 months of age. Mean language comprehension and expression at 18 months of the children in higher quartiles of HHFS were higher (P < 0.05) than those of the children in lower quartiles. Conclusions Household food security is positively associated with subsequent language development of rural Bangladeshi children. Early language development has been reported to predict later child development. Therefore, strategies to ensure HHFS status in Bangladesh and similar settings should be considered for optimum child development. [source] | |||||||||||||