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Monitoring Data (monitoring + data)
Selected AbstractsHealth Monitoring of Rehabilitated Concrete Bridges Using Distributed Optical Fiber SensingCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 6 2006Wei Zhang As newly developed techniques, distributed optical fiber sensing (DOFS) have gradually played a prominent role in structural health monitoring for the last decade. This article focuses on the employment of two types of DOFS, namely fiber Bragg grating (FBG) and Brillouin optical time domain reflectometry (BOTDR), into an integrated HMS for rehabilitated RC girder bridges by means of a series of static and dynamic loading tests to a simply supported RC T-beam strengthened by externally post-tensioned aramid fiber reinforced polymer (AFRP) tendons. Before the loading tests, a calibration test for FBG and another one for BOTDR were implemented to, respectively, obtain good linearity for both of them. Monitoring data were collected in real time during the process of external strengthening, static loading, and dynamic loading, respectively, all of which well identified the relevant structural state. The beam was finally vibrated for 2 million cycles and then loaded monotonously to failure. Based on the bending strength of externally prestressed members, ultimate values for the test specimen were numerically computed via a newly developed simplified model, which satisfactorily predicted the ultimate structural state of the beam. And then the alert values were adopted to compare with the monitoring results for safety alarm. The investigation results show a great deal of applicability for the integrated SHM by using both DOFS in rehabilitated concrete bridges strengthened by external prestressing. [source] Patch-Occupancy Modeling as a Method for Monitoring Changes in Forest Floristics: a Case Study in Southeastern AustraliaCONSERVATION BIOLOGY, Issue 3 2009TRENT D. PENMAN fuego prescrito; manejo adaptativo; modelo Bayesiamo; silvicultura; tala Abstract:,The ability to monitor changes in biodiversity is fundamental to demonstrating sustainable management practices of natural resources. Disturbance studies generally focus on responses at the plot scale, whereas landscape-scale responses are directly relevant to the development of sustainable forest management. Modeling changes in occupancy is one way to monitor landscape-scale responses. We used understory vegetation data collected over 16 years from a long-term study site in southeastern Australia. The site was subject to timber harvesting and frequent prescribed burning. We used occupancy models to examine the impacts of these disturbances on the distribution of 50 species of plants during the study. Timber harvesting influenced the distribution of 9 species, but these effects of harvesting were generally lost within 14 years. Repeated prescribed fire affected 22 species, but the heterogeneity of the burns reduced the predicted negative effects. Twenty-two species decreased over time independent of treatment, and only 5 species increased over time. These changes probably represent a natural response to a wildfire that occurred in 1973, 13 years before the study began. Occupancy modeling is a useful and flexible technique for analyzing monitoring data and it may also be suitable for inclusion within an adaptive-management framework for forest management. Resumen:,La habilidad para monitorear cambios en la biodiversidad es fundamental para demostrar el manejo sustentable de los recursos naturales. Los estudios de perturbación generalmente enfocan las respuestas a escala de parcela, mientras que las respuestas a escala de paisaje son directamente relevantes para el desarrollo del manejo sustentable de bosques. El modelado de cambios en la ocupación es una forma de monitorear respuestas a escala de paisaje. Utilizamos datos de la vegetación de sotobosque colectados a los largo de 16 años en un sitio de estudio a largo plazo en el sureste de Australia. El sitio fue sujeto a la cosecha de madera y a quemas prescritas frecuentes. Utilizamos modelos de ocupación para examinar los impactos de estas perturbaciones sobre la distribución de 50 especies de plantas. La cosecha de madera influyó en la distribución de nueve especies, pero los efectos de la cosecha generalmente se perdieron al cabo de 14 años. El fuego prescrito repetido afectó a 22 especies, pero la heterogeneidad de las quemas redujo los efectos negativos pronosticados. Veintidós especies decrecieron en el tiempo independientemente del tratamiento, y solo cinco especies incrementaron en el tiempo. Estos cambios probablemente representan una respuesta natural al incendio no controlado que ocurrió en 1973, 13 años antes de que comenzara el estudio. El modelado de la ocupación es una técnica útil y flexible para analizar datos de monitoreo y también puede ser adecuado para su inclusión en un marco de manejo adaptativo para la gestión de bosques. [source] Conservation Status as a Biodiversity Trend Indicator: Recommendations from a Decade of Listing Species at Risk in British ColumbiaCONSERVATION BIOLOGY, Issue 4 2005JAMES F. QUAYLE especies amenazadas; especies en peligro; estado del ambiente Abstract:,Species conservation status is commonly used as a broad-scale indicator of the state of biological diversity. To learn about its value for tracking trends, we examined provincial lists of terrestrial vertebrate species and subspecies at risk in British Columbia, Canada, for 1992 and 2002 to see whether changes in these lists reflected changes in the status of the taxa they represent. Examination of the case histories of individual species and subspecies showed that 65% of additions and deletions to the British Columbia Red List were the result of improvement in knowledge of species status, changes in assessment procedures, and refinements in taxonomy rather than actual changes in a species' status. Comparison to an alternate set of rank scores provided by NatureServe for taxa that appeared on both 1992 and 2002 British Columbia Red Lists revealed changes in status that were not reflected by movement from the list. Estimates of historical conservation status for species on the 1992 British Columbia Red List demonstrated ambiguity around the natural baseline with regard to tracking changes in list composition over time. We discourage the continued use of indicators based solely on conservation status as a means of tracking biodiversity. Instead we recommend advancing strategic indicators around species at risk based on long-term monitoring data, deliberate and explicitly stated baselines, and consistent methods of conservation ranking. Resumen:,El estatus de conservación de las especies comúnmente es utilizado como un indicador de escala amplia del estado de la diversidad biológica. En un esfuerzo por aprender sobre su valor para el seguimiento de tendencias, examinamos listas provinciales, para 1992 y 2002, de especies y subespecies de vertebrados terrestres en riesgo en Columbia Británica, Canadá, para ver si los cambios en estas listas reflejaban cambios en el estatus de los taxa que representan. El examen de la historia del caso de especies y subespecies individuales mostró que 65% de las adiciones y supresiones en la Lista Roja de Columbia Británica fueron el resultado de avances en el conocimiento del estatus de la especie, de cambios en los procedimientos de evaluación y de refinamientos en la taxonomía y no de cambios en el estatus de una especie. La comparación con un conjunto alternativo de valores de clasificación proporcionado por NatureServe para taxa que aparecieron tanto en la Lista Roja de Columbia Británica de 1992 como de 2002 reveló cambios en el estatus que no se reflejaron en movimientos en la lista. Estimaciones del estatus de conservación histórico de especies en la Lista Roja de Columbia Británica de 1992 demostraron ambigüedad alrededor de la línea de base natural en relación con el seguimiento de cambios en el tiempo en la composición de la lista. Desalentamos el uso continuo de indicadores basados solamente en el estatus de conservación como un medio para el seguimiento de biodiversidad. En cambio, recomendamos avanzar con indicadores estratégicos en torno a especies en riesgo con base en datos de monitoreo de largo plazo, en líneas básicas puestas de manifiesto deliberada y explícitamente y en métodos consistentes para la clasificación de la conservación. [source] Bacterial traits, organism mass, and numerical abundance in the detrital soil food web of Dutch agricultural grasslandsECOLOGY LETTERS, Issue 1 2005Christian Mulder Abstract This paper compares responses to environmental stress of the ecophysiological traits of organisms in the detrital soil food webs of grasslands in the Netherlands, using the relationship between average body mass M and numerical abundance N. The microbial biomass and biodiversity of belowground fauna were measured in 110 grasslands on sand, 85 of them farmed under organic, conventional and intensive management. Bacterial cell volume and abundance and electrophoretic DNA bands as well as bacterial activity in the form of either metabolic quotient (qCO2) or microbial quotient (Cmic/Corg) predicted the response of microorganisms to stress. For soil fauna, the logarithm of body mass log(M) was approximately linearly related to the logarithm of numerical abundance log(N) with slope near ,1, and the regression slope and the proportion of predatory species were lower in intensive agroecosystems (more reduced substrates with higher energy content). Linear regression of log(N) on log(M) had slope not far from ,3/4. The approach to monitoring data illustrated in this paper could be useful in assessing land-use quality. [source] A comparison of the effectiveness of group-based and pharmacy-led smoking cessation treatment in GlasgowADDICTION, Issue 2 2009Linda Bauld ABSTRACT Aim To compare the characteristics and outcomes of users accessing pharmacy and group-based smoking treatment. Design Observational study of administrative information linked with survey data. Setting Glasgow, Scotland. Participants A total of 1785 service users who set a quit date between March and May 2007. Intervention Smoking treatment services based in pharmacies providing one-to-one support, and in the community offering group support. Measurements Routine monitoring data included information about basic demographic characteristics, deprivation category of residence, nature of intervention and smoking status at 4-week follow-up determined by carbon monoxide (CO) readings ,10. These data were supplemented by information about socio-economic status and smoking-related behaviours obtained from consenting service recipients by treatment advisers. Findings In the pharmacy-based service 18.6 % of users (n = 1374) were CO-validated as a quitter at 4 weeks, compared with 35.5 % (n = 411) in the group-based service. In a multivariate model, restricted to participants (n = 1366) with data allowing adjustment for socio-demographic and behavioural characteristics and including interaction terms, users who accessed the group-based services were almost twice as likely (odds ratio 1.980; confidence interval 1.50,2.62) as those who used pharmacy-based support to have quit smoking at 4-week follow-up. Conclusions Specialist-led group-based services appear to have higher quit rates than one-to-one services provided by pharmacies but the pharmacy services treat many more smokers. More research is needed to determine what can be done to bring the success rates of pharmacy services up to those of specialist-led groups and how to expand access to group-based services. [source] Cost-effectiveness of pharmacy and group behavioural support smoking cessation services in GlasgowADDICTION, Issue 2 2009Kathleen A. Boyd ABSTRACT Aims Smokers attending group-based support for smoking cessation in Glasgow are significantly more likely to be successful than those attending pharmacy-based support. This study examined the cost-effectiveness of these two modes of support. Design Combination of observational study data and information from National Health Service (NHS) Greater Glasgow and Clyde smoking cessation services. Setting Glasgow, Scotland. Participants A total of 1979 smokers who accessed either of the cessation services between March and May 2007. Intervention Two smoking treatment services offering one-to-one support in pharmacies, and providing group counselling in the community. Measurements Routine monitoring data on resource use and smoking status (carbon monoxide-validated, self-reported, non-quitters and relapsers) at 4-week follow-up. Findings The incremental cost per 4-week quitter for pharmacy support was found to be approximately £772, and £1612 for group support, in comparison to self-quit cessation attempts. These findings compare favourably with previously published outcomes from cost-effectiveness smoking cessation studies. Assuming a relapse rate of 75% from 4 weeks to 1 year and a further 35% beyond 1 year, and combining this with an average of 1.98 quality adjusted life years (QALY) gained per permanent cessation, provides an estimated incremental cost per QALY of £4400 for the pharmacy service and £5400 for group support service. Conclusions Group support and pharmacy-based support for smoking cessation are both extremely cost-effective. [source] Comparison of air quality management strategies of PM10, SO2, and NOx by an industrial source complex model in BeijingENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 1 2007Gaoxiang Ying Abstract The primary air pollutants in the Beijing urban area are fine particulate matter (PM10), sulfur dioxide (SO2), and nitrogen oxides (NOx). Using suitable emission factors for point, area, and line sources from 20 categories of industrial, commercial, domestic and traffic, total yearly mean emissions were estimated at 103.3 kton of PM10, 209.9 kton of SO2, and 225.4 kton of NOx in 1999. To abate this elevated air pollution, three air quality management schemes are adopted. After the implementation, the annual mean ground-level concentrations of air pollutants are predicted by an industrial source complex short term (ISCST3) dispersion model and compared by the geographic information system (GIS). The ISCST3 dispersion model is used by inputting emission inventory and meteorological data with 1 h temporal and 1 km × 1 km spatial resolution. The model validity is verified by its agreement with monitoring data from Beijing's Environmental Protection Bureau. Results indicate that the levels of PM10, SO2, and NOx in Beijing are improved gradually because of the adoption of these three control schemes. The predicted annual mean concentrations decreased from 90.63 to 67.28 ,g/m3 for PM10, 57.94 to 31.77 ,g/m3 for SO2, and 119.97 to 73.83 ,g/m3 for NOx, respectively. © 2007 American Institute of Chemical Engineers Environ Prog 26:33,42, 2007. [source] Screening the Hanford tanks for trapped gasENVIRONMETRICS, Issue 5-6 2002Paul Whitney Abstract The Hanford Site is home to 177 large, underground nuclear waste storage tanks. This article describes a screening study carried out in the mid 1990s that used the tank waste level measurements to assess the tanks for potential flammable gas hazards. At the time of the study, 25 of the 177 tanks were on the flammable gas watch list. The use of this monitoring data provided additional insight, resulting in operational changes on the Hanford site. The waste level measurements used in this study were made primarily to monitor the tanks for leaks and intrusions. Four measurement devices are widely used in these tanks. Three of these measure the level of the waste surface. The remaining device measures from within a well embedded in the waste, thereby monitoring the liquid level even if the liquid level is below a dry waste crust. The data from each of the four measurement devices were utilized in this investigation. The analytic method used for this screening was to look for an inverse correlation between waste level measurements and ambient atmospheric pressure. If the waste level in a tank decreases with an increase in ambient atmospheric pressure, then the compressibility may be attributed to gas trapped within the waste. In this article, this methodology is not used to estimate the volume of gas trapped in the waste. Copyright © 2002 John Wiley & Sons, Ltd. [source] A high frequency kriging approach for non-stationary environmental processesENVIRONMETRICS, Issue 5 2001Montserrat Fuentes Abstract Emission reductions were mandated in the Clean Air Act Amendments of 1990 with the expectation that they would result in major reductions in the concentrations of atmospherically transported pollutants. The emission reductions are intended to reduce public health risks and to protect sensitive ecosystems. To determine whether the emission reductions are having the intended effect on atmospheric concentrations, monitoring data must be analyzed taking into consideration the spatial structure shown by the data. Maps of pollutant concentrations and fluxes are useful over different geopolitical boundaries, to discover when, where, and to what extent the U.S. Nation's air quality is improving or declining. Since the spatial covariance structure shown by the data changes with location, the standard kriging methodology for spatial interpolation cannot be used because it assumes stationarity of the process. We present a new methodology for spatial interpolation of non-stationary processes. In this method the field is represented locally as a stationary isotropic random field, but the parameters of the stationary random field are allowed to vary across space. A procedure for interpolation is presented that uses an expression for the spectral density at high frequencies. New fitting algorithms are developed using spectral approaches. In cases where the data are distributed exactly or approximately on a lattice, it is argued that spectral approaches have potentially enormous computational benefits compared with maximum likelihood. The methods are extended to interpolation questions using approximate Bayesian approaches to account for parameter uncertainty. We develop applications to obtain the total loading of pollutant concentrations and fluxes over different geo-political boundaries. Copyright © 2001 John Wiley & Sons, Ltd. [source] Assessing macroinvertebrate metrics for classifying acidified rivers across northern EuropeFRESHWATER BIOLOGY, Issue 7 2010S. JANNICKE MOE Summary 1. The effects of acidification on ecological status of rivers in Northern Europe must be assessed according to the EU Water Framework Directive (WFD). Several acidification metrics based on macroinvertebrates already exist in different countries, and the WFD requires that they be comparable across northern Europe. Thus, we compiled macroinvertebrate monitoring data from the U.K. (n = 191 samples), Norway (n = 740) and Sweden (n = 531) for analysis against pH. 2. We tested new and existing acidification metrics developed nationally and used within the Northern Geographical Intercalibration Group. The new metrics were based on the acidification sensitivity of selected species and are proposed as a first step towards a new common indicator for acidification for Northern Europe. 3. Metrics were assessed according to responsiveness to mean pH, degree of nonlinearity in response and consistency in responses across countries. We used flexible, nonparametric regression models to explore various properties of the pressure,response relationships. Metrics were also analysed with humic content (total organic carbon above/below 5 mg L,1) as a covariate. 4. Most metrics responded clearly to pH, with the following metrics explaining most of the variance: Acid Water Indicator Community, Number of ephemeropteran families, Medin's index, Multimetric Indicator of Stream Acidification and the new metric ,Proportion of sensitive Ephemeroptera'. 5. Most metrics were significantly higher in humic than in clear-water rivers, suggesting smaller acidification effects in humic rivers. This result supports the proposed use of humic level as a typological factor in the assessment of acidification. 6. Some potentially important effects could not be considered in this study, such as the additional effects of metals, episodic acidification and the contrasting effects of natural versus anthropogenic acidity. We advocate further data collection and testing of metrics to incorporate these factors. [source] Artificial neural network inversion of magnetotelluric data in terms of three-dimensional earth macroparametersGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 1 2000Vjacheslav Spichak The possibility of solving the three-dimensional (3-D) inverse problem of geoelectrics using the artificial neural network (ANN) approach is investigated. The properties of a supervised ANN based on the back-propagation scheme with three layers of neurons are studied, and the ANN architecture is adjusted. A model class consisting of a dipping dyke in the basement of a two-layer earth with the dyke in contact with the overburden is used for numerical experiments. Six macroparameters of the 3-D model, namely the thickness of the top layer, which coincides with the depth of the dyke (D), the conductivity ratio between the first and second layers (C1,/C2,), the conductivity contrast of the dyke (C/C2,), and the width (W ), length (L ) and dip angle of the dyke (A), are used. Various groups of magnetotelluric field components and their transformations are studied in order to estimate the effect of the data type used on the ANN recognition ability. It is found that use of only the xy - and yx -components of impedance phases results in reasonable recognition errors for all unknown parameters (D: 0.02 per cent, C1/C2: 8.4 per cent, C/C2: 26.8 per cent, W : 0.02 per cent, L : 0.02 per cent, A: 0.24 per cent). The influence of the size and shape of the training data pool (including the ,gaps in education' and ,no target' effects) on the recognition properties is studied. Results from numerous ANN tests demonstrate that the ANN possesses good enough interpolation and extrapolation abilities if the training data pool contains a sufficient number of representative data sets. The effect of noise is estimated by means of mixing the synthetic data with 30, 50 and 100 per cent Gaussian noise. The unusual behaviour of the recognition errors for some of the model parameters when the data become more noisy (in particular, the fact that an increase in error is followed by a decrease) indicates that the use of standard techniques of noise reduction may give an opposite result, so the development of a special noise treatment methodology is required. Thus, it is shown that ANN-based recognition can be successfully used for inversion if the data correspond to the model class familiar to the ANN. No initial guess regarding the parameters of the 3-D target or 1-D layering is required. The ability of the ANN to teach itself using real geophysical (not only electromagnetic) data measured at a given location over a sufficiently long period means that there is the potential to use this approach for interpreting monitoring data. [source] Stochastic Cost Optimization of Multistrategy DNAPL Site RemediationGROUND WATER MONITORING & REMEDIATION, Issue 3 2010Jack Parker This paper investigates numerical optimization of dense nonaqueous phase liquid (DNAPL) site remediation design considering effects of prediction and measurement uncertainty. Results are presented for a hypothetical problem involving remediation using thermal source reduction (TSR) and bioremediation with electron donor (ED) injection. Pump-and-treat is utilized as a backup measure if compliance criteria are not met. Remediation system design variables are optimized to minimize expected net present value (ENPV) cost. Adaptive criteria are assumed for real-time control of TSR and ED duration. Source zone dissolved concentration data enabled more reliable and lower cost operation of TSR than soil concentration data, but using both soil and dissolved data improved results sufficiently to more than offset the additional cost. Decisions to terminate remediation and monitoring or to initiate pump-and-treat are complicated by measurement noise. Simultaneous optimization of monitoring frequency, averaging period, and lookback periods to confirm decisions, in addition to remediation design variables, reduced ENPV cost. Results indicate that remediation design under conditions of uncertainty is affected by subtle interactions and tradeoffs between design variables, compliance rules, site characteristics, and uncertainty in model predictions and monitoring data. Optimized designs yielded cost savings of up to approximately 50% compared with a nonoptimized design based on common engineering practices. Significant improvements in accuracy and reductions in cost were achieved by recalibrating the model to data collected during remediation and re-optimizing design variables. Repeating this process periodically is advisable to minimize total costs and maximize reliability. [source] Paleosols in Central Illinois as Potential Sources of Ammonium in GroundwaterGROUND WATER MONITORING & REMEDIATION, Issue 4 2009Justin J. G. Glessner Glacially buried paleosols of pre-Holocene age were evaluated as potential sources for anomalously large concentrations of ammonium in groundwater in East Central Illinois. Ammonium has been detected at concentrations that are problematic to water treatment facilities (greater than 2.0 mg/L) in this region. Paleosols characterized for this study were of Quaternary age, specifically Robein Silt samples. Paleosol samples displayed significant capacity to both store and release ammonium through experiments measuring processes of sorption, ion exchange, and weathering. Bacteria and fungi within paleosols may significantly facilitate the leaching of ammonium into groundwater by the processes of assimilation and mineralization. Bacterial genetic material (DNA) was successfully extracted from the Robein Silt, purified, and amplified by polymerase chain reaction to produce 16S rRNA terminal restriction fragment length polymorphism (TRFLP) community analyses. The Robein Silt was found to have established diverse and viable bacterial communities. 16S rRNA TRFLP comparisons to well-known bacterial species yielded possible matches with facultative chemolithotrophs, cellulose consumers, nitrate reducers, and actinomycetes. It was concluded that the Robein Silt is both a source and reservoir for groundwater ammonium. Therefore, the occurrence of relatively large concentrations of ammonium in groundwater monitoring data may not necessarily be an indication of only anthropogenic contamination. The results of this study, however, need to be placed in a hydrological context to better understand whether paleosols can be a significant source of ammonium to drinking water supplies. [source] Impacts of a volcanic eruption on the forest bird community of Montserrat, Lesser AntillesIBIS, Issue 2 2007B. DALSGAARD Volcanic eruptions are an important and natural source of catastrophic disturbance to ecological communities. However, opportunities to study them are relatively rare. Here we report on the effects of the eruption of the Soufrière Hills volcano on the forest bird community of the Lesser Antillean island of Montserrat. The island's species-poor avifauna includes 11 restricted-range species, including the Critically Endangered endemic Montserrat Oriole Icterus oberi. Analysis of monitoring data from 1997 to 2005 indicates that counts of most species were substantially lower following major ashfalls. However, this effect was short-lived, with rapid population recovery in subsequent years. Furthermore, levels of seasonal rainfall appear to have been at least as important in determining population trends as ashfall. Overall, most species were at least as abundant at the end of the study as at the start, and no forest bird species have been extirpated from Montserrat. We discuss potential ecological drivers of ashfall impacts on populations: there is some evidence that terrestrial foragers were most severely affected. [source] Accelerating Malnutrition Reduction in OrissaIDS BULLETIN, Issue 4 2009Mona Sharma Orissa has performed better than the Indian average in terms of the rate of malnutrition reduction. This positive trend is supported by NFHS data, independent survey data and the State's own monitoring data. Despite this good news, absolute rates remain high with 40 per cent of children under five malnourished, rising to 54 per cent amongst the tribal population. Encouraging progress but recognition of a long way to go has triggered the Department of Women and Child Development to develop a new operational plan to accelerate the pace of malnutrition reduction. The Nutrition Plan is based on five principles, the key being targeting the most vulnerable in high burden districts. Review of national and international experience, analysis of the Department's data, plus primary data collection to fill information gaps, have created an evidence-based Plan which provides a challenging but realistic map for reaching an average annual malnutrition reduction of 3.5 percent. [source] Approaches for derivation of environmental quality criteria for substances applied in risk assessment of discharges from offshore drilling operationsINTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 2 2008Dag Altin Abstract In order to achieve the offshore petroleum industries "zero harm" goal to the environment, the environmental impact factor for drilling discharges was developed as a tool to identify and quantify the environmental risks associated with disposal of drilling discharges to the marine environment. As an initial step in this work the main categories of substances associated with drilling discharges and assumed to contribute to toxic or nontoxic stress were identified and evaluated for inclusion in the risk assessment. The selection were based on the known toxicological properties of the substances, or the total amount discharged together with their potential for accumulation in the water column or sediments to levels that could be expected to cause toxic or nontoxic stress to the biota. Based on these criteria 3 categories of chemicals were identified for risk assessment the water column and sediments: Natural organic substances, metals, and drilling fluid chemicals. Several approaches for deriving the environmentally safe threshold concentrations as predicted no effect concentrations were evaluated in the process. For the water column consensus were reached for using the species sensitivity distribution approach for metals and the assessment factor approach for natural organic substances and added drilling chemicals. For the sediments the equilibrium partitioning approach was selected for all three categories of chemicals. The theoretically derived sediment quality criteria were compared to field-derived threshold effect values based on statistical approaches applied on sediment monitoring data from the Norwegian Continental Shelf. The basis for derivation of predicted no effect concentration values for drilling discharges should be consistent with the principles of environmental risk assessment as described in the Technical Guidance Document on Risk Assessment issued by the European Union. [source] A numerical procedure for predicting rainfall-induced movements of active landslides along pre-existing slip surfacesINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 4 2008Michele Calvello Abstract A numerical model to predict landslide movements along pre-existing slip surfaces from rainfall data is presented. The model comprises: a transient seepage finite-element analysis to compute the variations of pore water pressures due to rainfall; a limit equilibrium stability analysis to compute the factors of safety along the slip surface associated with transient pore pressure conditions; an empirical relationship between the factor of safety and the rate of displacement of the slide along the slip surface; an optimization algorithm for the calibration of analyses and relationships based on available monitoring data. The model is validated with reference to a well-monitored active slide in central Italy, characterized by very slow movements occurring within a narrow band of weathered bedrock overlaid by a clayey silt colluvial cover. The model is conveniently divided and presented in two parts: a groundwater model and a kinematic model. In the first part, monthly recorded rainfall data are used as time-dependent flow boundary conditions of the transient seepage analysis, while piezometric levels are used to calibrate the analysis by minimizing the errors between monitoring data and computed pore pressures. In the second part, measured inclinometric movements are used to calibrate the empirical relationship between the rate of displacement along the slip surface and the factor of safety, whose variation with time is computed by a time-dependent stability analysis. Copyright © 2007 John Wiley & Sons, Ltd. [source] A model of human hunting impacts in multi-prey communitiesJOURNAL OF APPLIED ECOLOGY, Issue 5 2003J. Marcus Rowcliffe Summary 1The hunting of wild animals for consumption by people currently threatens many species with extinction. In the tropics, where the threat is most acute, hunting frequently targets many prey species simultaneously, yet our understanding of the dynamics of hunting in such multi-prey systems is limited. This study addressed this issue by modelling the effects of human hunters on prey population dynamics in a multi-species prey community. Both pursuit hunting (in which offtake depends partly on hunters' prey preferences) and trap hunting (in which the offtake is determined solely by random processes) were considered as submodels. 2The pursuit hunting submodel was validated against studies of subsistence hunting in tropical forests, while the trap hunting submodel was validated against data from five studies of offtake rates by snare hunters in subSaharan Africa. In all cases, observed prey removal rates were predicted well by the model. 3Simulations demonstrated the emergence of distinctive prey profiles at different intensities of hunting, related to sequences of overexploitation dependent on species' vulnerabilities to exploitation. 4Synthesis and applications. A model is developed to explore the impacts of harvesting on multi-species prey communities. Model predictions can be used to aid the interpretation of incomplete monitoring data, such as snapshots of the species taken by hunters. This will improve our ability to assess the sustainability of multi-species hunting systems using the limited information typically available in these cases. [source] Nonparametric population modeling of valproate pharmacokinetics in epileptic patients using routine serum monitoring data: implications for dosageJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 2 2004I. B. Bondareva Summary Therapeutic drug monitoring (TDM) of valproate (VAL) is important in the optimization of its therapy. The aim of the present work was to evaluate the ability of TDM using model-based, goal-oriented Bayesian adaptive control for help in planning, monitoring, and adjusting individualized VAL dosing regimens. USC*PACK software and routine TDM data were used to estimate population and individual pharmacokinetics of two commercially available VAL formulations in epileptic adult and pediatric patients on chronic VAL monotherapy. The population parameter values found were in agreement with values reported earlier. A statistically significant (P < 0.001) difference in median values of the absorption rate constant was found between enteric-coated and sustained-release VAL formulations. In our patients (aged 0·25,53 years), VAL clearance declined with age until adult values were reached at about age 10. Because of the large interindividual variability in PK behavior, the median population parameter values gave poor predictions of the observed VAL serum concentrations. In contrast, the Bayesian individualized models gave good predictions for all subjects in all populations. The Bayesian posterior individualized PK models were based on the population models described here and where most patients had two (a peak and a trough) measured serum concentrations. Repeated consultations and adjusted dosage regimens with some patients allowed us to evaluate any possible influence of dose-dependent VAL clearance on the precision of total VAL concentration predictions based on TDM data and the proposed population models. These nonparametric expectation maximization (NPEM) population models thus provide a useful tool for planning an initial dosage regimen of VAL to achieve desired target peak and trough serum concentration goals, coupled with TDM soon thereafter, as a peak,trough pair of serum concentrations, and Bayesian fitting to individualize the PK model for each patient. The nonparametric PK parameter distributions in these NPEM population models also permit their use by the new method of ,multiple model' dosage design, which allows the target goals to be achieved specifically with maximum precision. Software for both types of Bayesian adaptive control is now available to employ these population models in clinical practice. [source] 84 Linking environmental forcing, kelp forest habitat dynamics, and community structure in the northeast pacificJOURNAL OF PHYCOLOGY, Issue 2003B.P. Kinlan Habitat-forming species of large brown macroalgae (e.g., kelps) often differ from associated benthic species in resource requirements, sources of disturbance, and dispersal ability. Differences in environmental drivers and demographic processes may cause these habitats to fluctuate at spatial and temporal scales that differ from the "optimal" scale that would promote maximum abundance of any particular associate species. As a result, the spatiotemporal dynamics of habitat may exert important effects on benthic community structure and composition. To quantify the spatial and temporal dynamics of giant kelp (Macrocystis pyrifera), a key habitat-former in the NE Pacific, I analyzed a 34-year monthly time series of estimated canopy biomass spanning ,1500 km of coastline (7° of latitude) and digital maps of annual maximum canopy cover. Canopy biomass varied interannually at dominant periods of 4,5 y, 11,13 y and ,20 y, and spatial scales ranging from local (,30 km) to mesoscale (,100,150 km) and regional (,330 km). Temporal dynamics were strongly related to basin-scale climate fluctuations (El Niño-Southern Oscillation, Pacific Decadal Oscillation) and spatial patterns were correlated with coastline geomorphology. Digital canopy maps reveal that changes in biomass are associated with shifts in the spatial structure of the kelp habitat. Long-term subtidal community monitoring data from areas with markedly different spatial and temporal scales of kelp forest habitat structure reveal a complex but important influence of habitat dynamics on the distribution of life histories within kelp-associated communities. Future changes in the dynamics of Pacific climate fluctuations may have important implications for kelp forest community structure. [source] Integrated Modular Modeling of Water and Nutrients From Point and Nonpoint Sources in the Patuxent River Watershed,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2008Zhi-Jun Liu Abstract:, We present a simple modular landscape simulation model that is based on a watershed modeling framework in which different sets of processes occurring in a watershed can be simulated separately with different models. The model consists of three loosely coupled submodels: a rainfall-runoff model (TOPMODEL) for runoff generation in a subwatershed, a nutrient model for estimation of nutrients from nonpoint sources in a subwatershed, and a stream network model for integration of point and nonpoint sources in the routing process. The model performance was evaluated using monitoring data in the watershed of the Patuxent River, a tributary to the Chesapeake Bay in Maryland, from July 1997 through August 1999. Despite its simplicity, the landscape model predictions of streamflow, and sediment and nutrient loads were as good as or better than those of the Hydrological Simulation Program-Fortran model, one of the most widely used comprehensive watershed models. The landscape model was applied to predict discharges of water, sediment, silicate, organic carbon, nitrate, ammonium, organic nitrogen, total nitrogen, organic phosphorus, phosphate, and total phosphorus from the Patuxent watershed to its estuary. The predicted annual water discharge to the estuary was very close to the measured annual total in terms of percent errors for both years of the study period (,2%). The model predictions for loads of nutrients were also good (20-30%) or very good (<20%) with exceptions of sediment (40%), phosphate (36%), and organic carbon (53%) for Year 1. [source] Statistical methods for regular monitoring dataJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES B (STATISTICAL METHODOLOGY), Issue 5 2005Michael L. Stein Summary., Meteorological and environmental data that are collected at regular time intervals on a fixed monitoring network can be usefully studied combining ideas from multiple time series and spatial statistics, particularly when there are little or no missing data. This work investigates methods for modelling such data and ways of approximating the associated likelihood functions. Models for processes on the sphere crossed with time are emphasized, especially models that are not fully symmetric in space,time. Two approaches to obtaining such models are described. The first is to consider a rotated version of fully symmetric models for which we have explicit expressions for the covariance function. The second is based on a representation of space,time covariance functions that is spectral in just the time domain and is shown to lead to natural partially nonparametric asymmetric models on the sphere crossed with time. Various models are applied to a data set of daily winds at 11 sites in Ireland over 18 years. Spectral and space,time domain diagnostic procedures are used to assess the quality of the fits. The spectral-in-time modelling approach is shown to yield a good fit to many properties of the data and can be applied in a routine fashion relative to finding elaborate parametric models that describe the space,time dependences of the data about as well. [source] Monitoring terrestrial mammals in the UK: past, present and future, using lessons from the bird worldMAMMAL REVIEW, Issue 1-2 2004JESSAMY E. BATTERSBY ABSTRACT 1.,A monitoring network for UK terrestrial mammals, the Tracking Mammals Partnership, is currently being set up to provide a coordinated programme to collect surveillance and monitoring data. 2.,Monitoring UK mammals is important for a number of reasons including: setting conservation priorities; measuring the effects of conservation management; managing populations of problem species and the sustainable use of game species; assessing the effects of agriculture and other human activities; providing evidence for the need for policy change; and because of obligations under intergovernmental treaties and national legislation. 3.,The bird world, largely but not solely through the work carried out by the British Trust for Ornithology, has provided a useful model for mammal surveillance and some important lessons in setting up and running a UK wide multispecies monitoring programme. 4.,Lessons include the importance: of annual monitoring; of long-term data sets of population indices rather than absolute population sizes; and of the use of volunteers in data collection. 5.,Two scoping studies have been carried out to assess the feasibility and costs of setting up a mammal surveillance and monitoring network and the survey methods that could be used for different species. 6.,The Tracking Mammals Partnership, comprising 23 organizations, has the remit of implementing the recommendations of the scoping studies. There are a number of programmes operating within the Partnership including the National Dormouse Monitoring Programme, the National Bat Monitoring Programme and the Breeding Bird Survey Mammal Monitoring. There are also a number of pilot schemes being tested. 7.,Reports on the population trend data collected should enable more informed policy and management decisions concerning UK mammal species. [source] A numerical study of the effect of sea breeze circulation on photochemical pollution over a highly industrialized peninsulaMETEOROLOGICAL APPLICATIONS, Issue 1 2010Cristina Mangia Abstract Numerical simulations compared with measurements are used to investigate the effect of sea breeze circulation on the ozone accumulation over a highly industrialized peninsula in southern Italy, where high levels of ozone concentration are often registered. A frequent meteorological phenomenon in this region during weak summer synoptic conditions is the development of complex sea breeze systems from the coastlines, with convergence areas within the peninsula. A case study characterized by strong winds alternating with sea breeze circulations was selected. The simulations show that during weak synoptic conditions, sea breezes transport ozone and its precursors over land from the sea, as well as from the coastlines where the largest industrialized districts are localized. The overlapping breezes lead to ozone accumulation in the area where sea breeze convergence occurs. This may explain the high values of ozone registered close to the sea breeze convergence lines. The comparison between predictions and experimental data indicates that the numerical system successfully reproduces both weather and ground level ozone concentration in different meteorological conditions, resulting in a fundamental tool for both scientific comprehension of the evolution of air contaminants and interpretation of the monitoring data. Copyright © 2009 Royal Meteorological Society [source] Supermarket Sales Data: Feasibility and Applicability in Population Food and Nutrition MonitoringNUTRITION REVIEWS, Issue 1 2007Sandar Tin Tin MBBS Population food and nutrition monitoring plays a critical role in understanding suboptimal nutrition at the population level, yet current monitoring methods such as national surveys are not practical to undertake on a continuous basis. Supermarket sales data potentially address this gap by providing detailed, timely, and inexpensive monitoring data for informing policies and anticipating trends. This paper reviews 22 studies that used supermarket sales data to examine food purchasing patterns. Despite some methodological limitations, feasibility studies showed promising results. The potential and limitations of using supermarket sales data to supplement food and nutrition monitoring methods are discussed [source] Relationships between air pollution and preterm birth in CaliforniaPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 6 2006Mary Huynh Summary Air pollution from vehicular emissions and other combustion sources is related to cardiovascular and respiratory outcomes. However, few studies have investigated the relationship between air pollution and preterm birth, a primary cause of infant mortality and morbidity. This analysis examined the effect of fine particulate matter (PM2.5) and carbon monoxide (CO) on preterm birth in a matched case,control study. PM2.5 and CO monitoring data from the California Air Resources Board were linked to California birth certificate data for singletons born in 1999,2000. Each birth was mapped to the closest PM monitor within 5 miles of the home address. County-level CO measures were utilised to increase sample size and maintain a representative population. After exclusion of implausible birthweight,gestation combinations, preterm birth was defined as birth occurring between 24 and 36 weeks' gestation. Each of the 10 673 preterm cases was matched to three controls of term (39,44 weeks) gestation with a similar date of last menstrual period. Based on the case's gestational age, CO and PM2.5 exposures were calculated for total pregnancy, first month of pregnancy, and last 2 weeks of pregnancy. Exposures were divided into quartiles; the lowest quartile was the reference. Because of the matched design, conditional logistic regression was used to adjust for maternal race/ethnicity, age, parity, marital status and education. High total pregnancy PM2.5 exposure was associated with a small effect on preterm birth, after adjustment for maternal factors (adjusted odds ratio [AOR] = 1.15, [95% CI 1.07, 1.24]). The odds ratio did not change after adjustment for CO. Results were similar for PM2.5 exposure during the first month of pregnancy (AOR = 1.21, 95% CI [1.12, 1.30]) and the last 2 weeks of pregnancy (AOR = 1.17, 95% CI [1.09, 1.27]). Conversely, CO exposure at any time during pregnancy was not associated with preterm birth (AORs from 0.95 to 1.00). Maternal exposure to PM2.5, but not CO, is associated with preterm birth. This analysis did not show differences by timing of exposure, although more detailed examination may be needed. [source] Changing prevalence of asthma in Taiwanese adolescents: two surveys 6 years apartPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 2 2005Yung-Ling Lee This study compared the prevalence of asthma among Taiwanese adolescents with individual-level risk factors and municipal-level air pollution and meteorology data to determine whether changes in these factors could explain the observed change in prevalence. We conducted two national surveys of respiratory illness and symptoms in Taiwanese middle-school students in 1995,96 and 2001. The effects of personal and environmental factors were assessed and temporal changes of outdoor monitoring data were also compared with asthma prevalence difference. A total of 44,104 children from the 1995,96 survey and 11,048 children from the 2001 survey attended schools located within 1 km of 22 monitoring stations. Lifetime prevalences of physician-diagnosed and questionnaire-determined asthma increased during this period. After adjustment for potential risk factors, the prevalence differences were statistically unchanged. Although parental education level contributed most, changes in investigated personal and environmental factors might not explain the observed changes in asthma prevalence. Municipalities with higher temperature increase were significantly associated with prevalence difference in questionnaire-determined asthma. We concluded that correlates of the investigated individual-level factors, which have changed over time, still underlie changes in asthma prevalence. Increasing temperature might be the main reason for the rising trends of asthma in Taiwanese adolescents. [source] Use of the DirecNet Applied Treatment Algorithm (DATA) for diabetes management with a real-time continuous glucose monitor (the FreeStyle Navigator)PEDIATRIC DIABETES, Issue 2 2008Diabetes Research In Children Network (DirecNet) Study Group Background:, There are no published guidelines for use of real-time continuous glucose monitoring data by a patient; we therefore developed the DirecNet Applied Treatment Algorithm (DATA). The DATA provides algorithms for making diabetes management decisions using glucose values: (i) in real time which include the direction and rate of change of glucose levels, and (ii) retrospectively based on downloaded sensor data. Objective:, To evaluate the use and effectiveness of the DATA in children with diabetes using a real-time continuous glucose sensor (the FreeStyle Navigator). Subjects:, Thirty children and adolescents (mean ± standard deviation age = 11.2 ± 4.1 yr) receiving insulin pump therapy. Methods:, Subjects were instructed on use of the DATA and were asked to download their Navigator weekly to review glucose patterns. An Algorithm Satisfaction Questionnaire was completed at 3, 7, and 13 wk. Results:, At 13 wk, all of the subjects and all but one parent thought that the DATA gave good, clear directions for insulin dosing, and thought the guidelines improved their postprandial glucose levels. In responding to alarms, 86% of patients used the DATA at least 50% of the time at 3 wk, and 59% reported doing so at 13 wk. Similar results were seen in using the DATA to adjust premeal bolus doses of insulin. Conclusions:, These results show the feasibility of implementing the DATA when real-time continuous glucose monitoring is initiated and support its use in future clinical trials of real-time continuous glucose monitoring. [source] Estimating exposures in the asphalt industry for an international epidemiological cohort study of cancer riskAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 1 2003Igor Burstyn Abstract Background An exposure matrix (EM) for known and suspected carcinogens was required for a multicenter international cohort study of cancer risk and bitumen among asphalt workers. Methods Production characteristics in companies enrolled in the study were ascertained through use of a company questionnaire (CQ). Exposures to coal tar, bitumen fume, organic vapor, polycyclic aromatic hydrocarbons, diesel fume, silica, and asbestos were assessed semi-quantitatively using information from CQs, expert judgment, and statistical models. Exposures of road paving workers to bitumen fume, organic vapor, and benzo(a)pyrene were estimated quantitatively by applying regression models, based on monitoring data, to exposure scenarios identified by the CQs. Results Exposures estimates were derived for 217 companies enrolled in the cohort, plus the Swedish asphalt paving industry in general. Most companies were engaged in road paving and asphalt mixing, but some also participated in general construction and roofing. Coal tar use was most common in Denmark and The Netherlands, but the practice is now obsolete. Quantitative estimates of exposure to bitumen fume, organic vapor, and benzo(a)pyrene for pavers, and semi-quantitative estimates of exposure to these agents among all subjects were strongly correlated. Semi-quantitative estimates of exposure to bitumen fume and coal tar exposures were only moderately correlated. EM assessed non-monotonic historical decrease in exposures to all agents assessed except silica and diesel exhaust. Conclusions We produced a data-driven EM using methodology that can be adapted for other multicenter studies. Am. J. Ind. Med. 43:3,17, 2003. © 2003 Wiley-Liss, Inc. [source] Simultaneous determination of t,t -muconic, S -phenylmercapturic and S -benzylmercapturic acids in urine by a rapid and sensitive liquid chromatography/electrospray tandem mass spectrometry methodRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 17 2004Anna Barbieri We describe a rapid and sensitive high-performance liquid chromatography/electrospray tandem mass spectrometry (HPLC/ESI-MS/MS) method for simultaneous determination of the most relevant metabolites of benzene and toluene, t,t- muconic acid (t,t -MA), S -phenylmercapturic acid (S-PMA), and S -benzylmercapturic acid (S-BMA). Urine samples were purified before analysis by solid-phase microextraction (SPE) on SAX cartridges with 50,mg sorbent mass. The developed method fulfils all the standard requirements of precision and accuracy. Calibration curves were linear within the concentration range of the standards (0,80,,g/Lurine for t,t -MA, and 0,25,,g/Lurine for S-PMA and S-BMA), and had correlation coefficients ,0.997. Limits of detection were 6.0,,g/L for t,t -MA, 0.3,,g/L for S-PMA, and 0.4,,g/L for S-BMA. The method was used to determine t,t -MA, S-PMA and S-BMA levels in urine of 31 gasoline-station workers, with personal monitoring data obtained from radial symmetry passive diffusive samplers. In the context of mean work-shift exposures of 75.9,,g/m3 (range 9.4,220.2) for benzene and 331.9,,g/m3 (78.2,932.1) for toluene, metabolite concentrations in end-of-shift urine samples ranged from 23.5,275.3,,g/gcreatinine for t,t -MA, non-detectable to 0.9,,g/gcreatinine for S-PMA, and 3.8,74.8,,g/gcreatinine for S-BMA. No significant correlation was found between the environmental concentrations and urinary metabolites (p,>,0.05 for all cases); the ratios of benzene metabolites could be influenced by exposure levels and co-exposure to xylenes and toluene. The high throughput of this procedure should facilitate exploration of the metabolic effects of benzene-related co-exposure to toluene and alkylbenzenes in large populations of subjects exposed to gasoline. Copyright © 2004 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||||||||||||||