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Primary Control (primary + control)
Selected AbstractsFactors that distinguish serious versus less severe Strain and sprain injuries: An analysis of electric utility workersAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 3 2009Michael A. Kelsh PhD Abstract Background Occupational sprain and strain injuries are one of the most common types of nonfatal occupational injuries and a significant source of lost workdays. This study examines factors associated with severe work-related sprain/strain injuries to the back, shoulder, and knees. Methods A synthetic case,control study was performed (controls were selected from the same pool of utility workers as cases). Cases included all electric utility workers who had experienced a severe work-related sprain/strain injury to the back, knee, or shoulder. Primary controls were selected from all workers who had sustained a minor injury. Secondary controls were selected from employees with a minor sprain/strain injury to the back, knee, or shoulder. Multivariate logistic regression models were used to estimate odds ratios and 95% confidence intervals. Results Workers 41 years and older were more likely to have experienced severe shoulder sprain/strain injuries [Age 41,50: OR,=,3.62, 95% CI: 1.71,7.65; age 51 and older: OR,=,4.49, 95% CI: 1.89,10.67] and severe back sprain/strain injuries [Age 41,50: OR,=,1.70, 95% CI: 1.06,2.33; age 51 and older: OR,=,1.5, 95% CI: 0.90,2.52]. Line workers and maintenance workers had an increased risk of serious sprain/strain injuries. Gender and day of week were not significantly associated with sprain/strain injuries. Discussion Though this study is limited by available data, future studies may benefit from this preliminary examination of occupational and demographic characteristics associated with serious sprain/strain injuries among electric utility workers. Am. J. Ind. Med. 52:210,220, 2009. © 2008 Wiley-Liss, Inc. [source] Amount and controls of the quaternary denudation in the Ardennes massif (western Europe)EARTH SURFACE PROCESSES AND LANDFORMS, Issue 11 2009A. Demoulin Abstract It is still debated whether the primary control on the middle Pleistocene denudation of the uplifted Ardennes massif (western Europe) is tectonic or climatic. Here, based on geomorphological observations, we calculate the amount of river incision and interfluve denudation in the Meuse basin upstream of Maastricht since 0·7 Ma and we show that the main response to tectonic forcing was incision. This allows us to provide first-order estimates of the tectonic and climatic contributions to the denudation of the Ardennes. From a dataset of 71 remnants of a terrace level dated ,0·7 Ma, we first derive a basin-scale functional relationship linking incision with distances to the regional base level (Lc) and to the source (Ls) in the Ourthe basin (pertaining to the Ardennian part of the Meuse basin). Expressed as I = I0*(1 , a*Lcb/Lsc), I0 being the incision measured at the basin outlet, this relationship calculates that river incision has removed 84 km3 of rock in the Meuse basin upstream of Maastricht since 0·7 Ma. In the same time, 292 km3 were eroded from the interfluves. A comparison of these volumes shows that the tectonically forced river incision accounts for ,22% of the total post-0·7 Ma denudation. Furthermore, the mean denudation rate corresponding to our geomorphological estimate of the overall denudation in the Meuse basin since 0·7 Ma amounts to 27 mm/ky, a figure significantly lower than the ,40 mm/ky mean rate derived from 10Be studies of terrace deposits of the Meuse (Schaller et al., 2004). This suggests that, taken as a basin average, the 10Be-derived rate is overestimated, probably due to an overrepresentation of the erosion products of the rapidly incising valleys in the alluvial deposits. Copyright © 2009 John Wiley & Sons, Ltd. [source] Spatial prediction of river channel topography by krigingEARTH SURFACE PROCESSES AND LANDFORMS, Issue 6 2008Carl J. Legleiter Abstract Topographic information is fundamental to geomorphic inquiry, and spatial prediction of bed elevation from irregular survey data is an important component of many reach-scale studies. Kriging is a geostatistical technique for obtaining these predictions along with measures of their reliability, and this paper outlines a specialized framework intended for application to river channels. Our modular approach includes an algorithm for transforming the coordinates of data and prediction locations to a channel-centered coordinate system, several different methods of representing the trend component of topographic variation and search strategies that incorporate geomorphic information to determine which survey data are used to make a prediction at a specific location. For example, a relationship between curvature and the lateral position of maximum depth can be used to include cross-sectional asymmetry in a two-dimensional trend surface model, and topographic breaklines can be used to restrict which data are retained in a local neighborhood around each prediction location. Using survey data from a restored gravel-bed river, we demonstrate how transformation to the channel-centered coordinate system facilitates interpretation of the variogram, a statistical model of reach-scale spatial structure used in kriging, and how the choice of a trend model affects the variogram of the residuals from that trend. Similarly, we show how decomposing kriging predictions into their trend and residual components can yield useful information on channel morphology. Cross-validation analyses involving different data configurations and kriging variants indicate that kriging is quite robust and that survey density is the primary control on the accuracy of bed elevation predictions. The root mean-square error of these predictions is directly proportional to the spacing between surveyed cross-sections, even in a reconfigured channel with a relatively simple morphology; sophisticated methods of spatial prediction are no substitute for field data. Copyright © 2007 John Wiley & Sons, Ltd. [source] Mineral surfaces and soil organic matterEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2003K. Kaiser Summary The organic carbon content of soil is positively related to the specific surface area (SSA), but large amounts of organic matter in soil result in reduced SSA as determined by applying the Brunauer,Emmett,Teller (BET) equation to the adsorption of N2. To elucidate some of the controlling mechanisms of this relation, we determined the SSA and the enthalpy of N2 adsorption of separates with a density > 1.6 g cm,3 from 196 mineral horizons of forest soils before and after removal of organic matter with NaOCl. Likewise, we investigated these characteristics before and after sorption of increasing amounts of organic matter to four mineral soil samples, oxides (amorphous Al(OH)3, gibbsite, ferrihydrite, goethite, haematite), and phyllosilicates (kaolinite, illite). Sorption of organic matter reduced the SSA, depending on the amount sorbed and the type of mineral. The reduction in SSA decreased at larger organic matter loadings. The SSA of the mineral soils was positively related to the content of Fe oxyhydroxides and negatively related to the content of organic C. The strong reduction in SSA at small loadings was due primarily to the decrease in the micropores to which N2 was accessible. This suggests preferential sorption of organic matter at reactive sites in or at the mouths of micropores during the initial sorption and attachment to less reactive sites at increasing loadings. The exponential decrease of the heat of gas adsorption with the surface loading points also to a filling or clogging of micropores at early stages of organic matter accumulation. Desorption induced a small recovery of the total SSA but not of the micropore surface area. Destruction of organic matter increased the SSA of all soil samples. The SSA of the uncovered mineral matrix related strongly to the amounts of Fe oxyhydroxides and the clay. Normalized to C removed, the increase in SSA was small in topsoils and illuvial horizons of Podzols rich in C and large for the subsoils containing little C. This suggests that micropores preferentially associate with organic matter, especially at small loadings. The coverage of the surface of the soil mineral matrix as calculated from the SSA before and after destruction of organic matter was correlated only with depth, and the relation appeared to be linear. We conclude that mineralogy is the primary control of the relation between surface area and sorption of organic matter within same soil compartments (i.e. horizons). But at the scale of complete profiles, the surface accumulation and stabilization of organic matter is additionally determined by its input. [source] An advanced methodology for steady-state security assessment of power systemsEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 4 2001D. P. Popovic The basic objective of this paper is to present the relevant aspects of an advanced methodology for steady-state security assessment of power systems. This methodology consists of the following relevant parts: procedure for forming the unified external network equivalents, with adaptive buffer system selection, procedure for fast contingency selection and simple method for the fast and sufficiently accurate assessment of dynamic variation of power system frequency during the time of its primary control. For the potentially critical contingency, the continuation of iterative procedure is performed. Full contingency analysis is based on specially developed method, which enables successive solution of the load-flow problem for a set of characteristic post-dynamic quasi-stationary states. The characteristics of the developed methodology are tested on the example of the existing electric power interconnection in the Balkans. [source] Overpressure and petroleum generation and accumulation in the Dongying Depression of the Bohaiwan Basin, ChinaGEOFLUIDS (ELECTRONIC), Issue 4 2001X. Xie Abstract The occurrence of abnormally high formation pressures in the Dongying Depression of the Bohaiwan Basin, a prolific oil-producing province in China, is controlled by rapid sedimentation and the distribution of centres of active petroleum generation. Abnormally high pressures, demonstrated by drill stem test (DST) and well log data, occur in the third and fourth members (Es3 and Es4) of the Eocene Shahejie Formation. Pressure gradients in these members commonly fall in the range 0.012,0.016 MPa m,1, although gradients as high as 0.018 MPa m,1 have been encountered. The zone of strongest overpressuring coincides with the areas in the central basin where the principal lacustrine source rocks, which comprise types I and II kerogen and have a high organic carbon content (>2%, ranging to 7.3%), are actively generating petroleum at the present day. The magnitude of overpressuring is related not only to the burial depth of the source rocks, but to the types of kerogen they contain. In the central basin, the pressure gradient within submember Es32, which contains predominantly type II kerogen, falls in the range 0.013,0.014 MPa m,1. Larger gradients of 0.014,0.016 MPa m,1 occur in submember Es33 and member Es4, which contain mixed type I and II kerogen. Numerical modelling indicates that, although overpressures are influenced by hydrocarbon generation, the primary control on overpressure in the basin comes from the effects of sediment compaction disequilibrium. A large number of oil pools have been discovered in the domes and faulted anticlines of the normally pressured strata overlying the overpressured sediments; the results of this study suggest that isolated sandstone reservoirs within the overpressured zone itself offer significant hydrocarbon potential. [source] Eastern versus Western Control Beliefs at Work: An Investigation of Secondary Control, Socioinstrumental Control, and Work Locus of Control in China and the USAPPLIED PSYCHOLOGY, Issue 1 2004Paul E. Spector La théorie et la recherche concernant les croyances (LOC) et les perceptions du contrôle suggèrent que les Asiatiques tendent à obtenir des scores plus bas et àêtre plus passifs que les Américains, mais ces travaux ont été menés à l'aide de concepts et d'échelles développés principalement aux USA qui certifient une primauté du contrôle interne (ex: en changeant l'environnement pour l'adapter à soi). Une équipe de recherche internationale a étendu la notion de croyance dans le contrôle en développant des échelles qui permettent de reconsidérer la notion en faisant état de croyances secondaires dans le contrôle (ex: en adaptant le soi à l'environnement) et de faire état d'un concept nouveau de croyances socio-instrumentales (ex: le contrôle par les relations interpersonelles) qui permettent de rendre compte de manière plus pertinente des croyances en un contrôle dans les cultures collectivistes. Nous nous attendions à ce que, par l'utilisation d'échelles culturellement appropriées, les Américains n'obtiennent pas une croyance en un contrôle plus importante que les Asiatiques. Les hypothèses ont été partiellement confirmées en ce que les Américains se sont montrés comme obtenant un contrôle plus bas que les Chinois (de Hong Kong et de RP de Chine) sur ces échelles. Il est suggéré que voir les Asiatiques comme évitant passivement le contrôle au travail peut être incorrect et dû aux insuffisances de contrôle socio-instrumental. Research and theory concerning beliefs (locus of control) and perceptions of control suggest that Asians tend to be lower and more passive than Americans, but this work has been conducted mainly with US-developed constructs and scales that assess primary control (i.e. changing the environment to adapt to the self). An international research team expanded the notion of control beliefs by developing scales to assess secondary control beliefs (i.e. adapting the self to the environment) and the new construct of socioinstrumental control beliefs (i.e. control via interpersonal relationships), both of which were thought to better fit the control beliefs of collectivist cultures than Western-developed control scales. We expected that, when culturally appropriate scales were employed, Americans would not show higher control beliefs than Asians. Hypotheses were partially confirmed that Americans would be lower than Chinese (Hong Kong and PR China) on these new scales. It is suggested that views of Asians as passive avoiders of control at work may be incorrect and due to the overlooking of socioinstrumental control. [source] Combinatorial, selective and reversible control of gene expression using oligodeoxynucleotides in a cell-free protein synthesis system,BIOTECHNOLOGY & BIOENGINEERING, Issue 2 2009Jung-Won Keum Abstract Herein we describe the methods for selective and reversible regulation of gene expression using antisense oligodeoxynucleotides (ODNs) in a cell-free protein synthesis system programmed with multiple DNAs. Either a complete shut down or controlled level of gene expression was attained through the antisense ODN-mediated regulation of mRNA stability in the reaction mixture. In addition to the primary control of gene expression, we also demonstrate that the inhibition of protein synthesis can be reversed by using an anti-antisense ODN sequence that strips the antisense ODN off the target sequence of mRNA. As a result, sequential additions of the antisense and anti-antisense ODNs enabled the stop-and-go expression of protein molecules. Through the on-demand regulation of gene expression, presented results will provide a versatile platform for the analysis and understanding of the complicated networks of biological components. Biotechnol. Bioeng. 2009;102: 577,582. © 2008 Wiley Periodicals, Inc. [source] Geochemistry of Heavy Oil in the T Block, Oriente Basin and its Origin MechanismACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 2 2010Ying HU Abstract: Exploration and development experience show that there is obvious oil gravity difference between the southern part and northern part of the "M1" reservoir in the Fanny oil field in the slope of the Oriente Basin, Ecuador. The American Petroleum Institute Gravity (API) values of oils in the northern part are higher than the one in the southern part of the Fanny oil field, with the values of 20° and 10.0°,13.0°, respectively. So the primary purpose of this study was to analyze the heavy oil characteristics of biodegradation and the oil,oil correlation according to the biomarker data and the ,13C signature of oil samples from T block. The results of the hydrocarbon gas chromatography fingermark and the inversion attribute characteristics indicated that there are fluid compartments between the "M1" reservoir of Fanny south. Finally, the models of oil,gas accumulation under the control of multiple-activities of complicated fault systems, as well as the origin of heavy oil, are contended. The early stage oils from the western part of the basin were biodegraded heavily in varying degrees in the whole basin, and the later stage oils were derived from the southern part in a large scale and were mature and lighter. Generally, oil mixing is the primary control of net oil properties, such as API gravity in Oriente Basin. We therefore predicted that the API gravity variation of oil pools radically depends on the injection amount of the later stage oil. Because of the shale barrier in the "M1" reservoir of Fanny south, the later stage hydrocarbon could not pass through and contribute to increase the oil API value. [source] Contribution of deep-seated bedrock landslides to erosion of a glaciated basin in southern AlaskaEARTH SURFACE PROCESSES AND LANDFORMS, Issue 9 2005Ann M. Arsenault Abstract Landslides represent a key component of catchment-scale denudation, though their relative contribution to the erosion of glaciated basins is not well known. Bedrock landslide contribution was investigated on the surface of one of eleven glaciers on a glaciated ridge in the Chugach-St Elias Range of southern Alaska, where the debris from four major landslides is easily distinguished from moraines and other supraglacial material. A series of aerial and satellite photos from 1972 to 2000 and field observations in 2001 and 2002 indicate that three of four landslides have fallen onto the surface of the glacier since about 1978. The landslides, which originated from the steeply dipping (60,70°) bedrock walls, were deposited onto the glacier in the ablation zone and are currently being transported downstream supraglacially. Individual glacial valleys with topographic relief of ,400 m are cut into high-grade metamorphic rock characterized by a steep north-dipping foliation and fractured by numerous large joints. Measurements of landslide area and average thickness obtained from high-resolution survey data indicate a total landslide volume of ,2·3 × 105 m3. This volume suggests a basin-averaged erosion rate from landslides of 0·48 mm a,1. An overall basin-scale erosion rate of 0·7 to 1·7 mm a,1 can be inferred, but depends on the percentage of the total-basin sediment yield contributed by supraglacial sources. A mean rockwall retreat rate of 6·7 mm a,1 is calculated and is considerably higher than published rates, which range from 0·04 to 4·0 mm a,1. Controls on landslide generation include seismicity, freeze,thaw processes, topography, rock strength, and debuttressing. It is likely all of these factors contribute to failure, although the primary controls for the landslides in this study are thought to be rock strength and topography. The absence of landslides on ten of the eleven glaciers on this ridge is attributed to landslide magnitude,frequency relationships and short temporal scale of this study. Large-volume bedrock landslides (>100 000 m3) may have low frequency, occurring less than once in a 55-year time frame. Copyright © 2005 John Wiley & Sons, Ltd. [source] Wavelet analysis of inter-annual variability in the runoff regimes of glacial and nival stream catchments, Bow Lake, AlbertaHYDROLOGICAL PROCESSES, Issue 6 2003Melissa Lafrenière Abstract Continuous wavelet analyses of hourly time series of air temperature, stream discharge, and precipitation are used to compare the seasonal and inter-annual variability in hydrological regimes of the two principal streams feeding Bow Lake, Banff National Park, Alberta: the glacial stream draining the Wapta Icefields, and the snowmelt-fed Bow River. The goal is to understand how water sources and flow routing differ between the two catchments. Wavelet spectra and cross-wavelet spectra were determined for air temperature and discharge from the two streams for summers (June,September) 1997,2000, and for rainfall and discharge for the summers of 1999 and 2000. The diurnal signal of the glacial runoff was orders of magnitude higher in 1998 than in other years, indicating that significant ice exposure and the development of channelized glacial drainage occurred as a result of the 1997,98 El Niño conditions. Early retreat of the snowpack in 1997 and 1998 led to a significant summer-long input of melt runoff from a small area of ice cover in the Bow River catchment; but such inputs were not apparent in 1999 and 2000, when snow cover was more extensive. Rainfall had a stronger influence on runoff and followed quicker flow paths in the Bow River catchment than in the glacial catchment. Snowpack thickness and catchment size were the primary controls on the phase relationship between temperature and discharge at diurnal time scales. Wavelet analysis is a fast and effective means to characterize runoff, temperature, and precipitation regimes and their interrelationships and inter-annual variability. The technique is effective at identifying inter-annual and seasonal changes in the relative contributions of different water sources to runoff, and changes in the time required for routing of diurnal meltwater pulses through a catchment. However, it is less effective at identifying changes/differences in the type of the flow routing (e.g. overland flow versus through flow) between or within catchments. Copyright © 2003 John Wiley & Sons, Ltd. [source] |