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Control Measures (control + measure)
Kinds of Control Measures Selected AbstractsIntroduction of Infection Control Measures to Reduce Infection Associated With Implantable Pain Therapy DevicesPAIN PRACTICE, Issue 3 2007Abram H. Burgher MD Abstract Introduction: Implantable pain therapy devices for chronic pain include spinal cord stimulators (SCS) and intrathecal drug delivery systems (IDDS). A number of different complications can occur after implantation of these devices, but among the most serious is infection. Based on Centers for Disease Control and Prevention guidelines for prevention of surgical site infection, published literature on infection risk with implantable pain therapy devices, and recommendations from groups within our own our institution, we introduced infection control measures for all patients receiving either SCS or IDDS. Methods: After approval from the Institutional Review Board, we performed a retrospective review of patients undergoing primary implantation of SCS or IDDS before and after introduction at our institution of safety measures designed to reduce device-related infection. We compared infection incidence and compliance to infection precautions before and after introduction of these measures. Results: Thirty-four SCS or IDDS were implanted before implementation of the infection control measures and 58 were placed after. Five device-related infections occurred. Adherence to most infection precautions improved during the study period, but 100% compliance was seen only with venue used for implantation. Infection incidence declined after introduction of the safety measures, but the reduction was not statistically significant. Conclusions: Introduction of infection control measures for implantable pain therapy devices improved adherence to most infection precautions in our practice. Lack of specific documentation could have hindered practice surveillance within our group. A tool to document performance of infection control measures would be useful not only as a marker of compliance but could also serve as a reminder to perform certain safety measures. [source] Comparing strategies for controlling an African pest rodent: an empirically based theoretical studyJOURNAL OF APPLIED ECOLOGY, Issue 5 2001Nils Chr. Summary 1Small rodents in general and the multimammate rat Mastomys natalensis in particular cause major economic losses in Africa through damage to crops. Attempts to develop dynamic population models for this and other pest rodents are ongoing. 2Demographic estimates from a capture,mark,recapture (CMR) study in Tanzania were used to parameterize a population model for this species. This model incorporated three functional age categories (juveniles, subadults and adults) of both sexes and used density-dependent and density-independent factors, the latter represented by rainfall. 3The model was used to analyse the effect of rodent control on the population dynamics and resulting number of rats. Control measures affecting survival as well as reproduction were considered. 4The model showed that control measures reducing survival will only have long-term effects on population size if they are also applied when rodent densities are low. Control measures applied only when rodent densities are high will not have persistent effects, even at high mortality rates. 5The model demonstrated that control measures reducing reproduction are likely to prevent Mastomys outbreaks, but will keep densities low over a long period only when the contraceptive effect is strong (> 75% reduction). 6Provided that CMR data are available, we recommend developing Leslie-type population models for rodent pests on the basis of CMR-estimated demographic schedules. Such models have great potential in rodent management and allow the evaluation of different strategies. 7Besides improving the ecological basis of the population modelling, economic considerations need to be incorporated into decisions about rodent control. We suggest that appropriate population models will provide important input into such decision making. [source] Occurrence of Pseudomonas avellanae (Psallidas) Janse et al. and related pseudomonads on wild Corylus avellana trees and genetic relationships with strains isolated from cultivated hazelnutsJOURNAL OF PHYTOPATHOLOGY, Issue 9-10 2000M. Scortichini Surveys in submediterranean forests of central Italy were carried out during 1996,98 to verify the possible presence of bacterial canker caused by Pseudomonas avellanae in wild hazelnut trees (Corylus avellana L.). Wilted twigs were noticed several times especially in summer. In other cases, wild C. avellana trees growing near to hazelnut orchards appeared completely wilted. Isolates that were pathogenic to C. avellana, showing a different degree of virulence, were obtained in both situations. Biochemical, physiological and nutritional tests as well as the comparison of whole-cell protein profiles, revealed the presence of 16 isolates identical to P. avellanae reference strains that had previously been isolated in the same area and five deviating isolates. Repetitive-PCR genomic fingerprinting performed by using BOX (Box elements), ERIC (Enterobacterial Repetitive Interkingdom Consensus) and REP (Repetitive Extragenic Palindromic) primer sets and analysed by means of upgma, revealed the existence of two main groups of pseudomonads pathogenic to C. avellana. Group A includes P. avellanae strains isolated in northern Greece and central Italy as well as the isolates obtained from the wild C. avellana trees grown near the cultivated hazelnut orchards. Group B includes strains previously isolated in northern, southern and other areas of central Italy as well as the isolates obtained from C. avellana wild trees showing twig dieback. Control measures should be taken to avoid the spread of bacterial canker of hazelnut in the forests of central Italy. [source] Elevated levels of IgG3 and IgG4 subclass in paediatric cases of kala azarPARASITE IMMUNOLOGY, Issue 8 2008N. A. ANSARI SUMMARY Visceral leishmaniasis (VL) or Kala azar (KA) is a systemic disease caused by the parasites of the Leishmania donovani complex. Control measures rely on treatment with antileishmanial agents, however, fraught with problems such as toxicity or drug resistance. The incidence rate is on the rise for children, for reasons yet undefined. Previously we have shown significantly elevated level of IL-10 in children compared to adult KA cases. Here, antileishmanial antibody and C-reactive protein (CRP) levels were investigated in paediatrics and adult patients of KA and post-KA dermal leishmaniasis (PKDL). Level of IgG4 was significantly elevated in PKDL compared to KA, although total IgG and IgG1 were significantly lower. The antileishmania antibody levels of subclass IgG3 and IgG4 were found significantly elevated in paediatrics, however, levels of IgG, IgG1, IgG2 and CRP were comparable in paediatric and adult KA cases. In case of PKDL, levels of IgG and it subclass were similar in the two groups. No significant difference in antileishmanial antibody level was noticed between macular or polymorphic cases of PKDL. The differential antibody intensity in paediatric cases, together with significant level of circulating IL-10, could be considered as a marker of differential disease susceptibility. [source] Breeding for resistance to whitefly-transmitted geminivirusesANNALS OF APPLIED BIOLOGY, Issue 2 2002MOSHE LAPIDOT Summary Geminiviruses comprise a large and diverse family of viruses that infect a wide range of important monocotyledonous and dicotyledonous crop species and cause significant yield losses. The family Geminiviridae is divided into three genera, one of which is Begomovirus. Species of this genus are transmitted by the whitefly Bemisia tabaci in a persistent, circulative manner and infect dicotyledonous plants. Severe population outbreaks of B. tabaci are usually accompanied by a high incidence of begomoviruses. During the last two decades, there has been a worldwide spread of the B biotype of B. tabaci, accompanied by the emergence of whitefly-transmitted geminiviruses. Control measures in infected regions are based mainly on limitation of vector populations, using chemicals or physical barriers. However, under conditions of severe whitefly attack, none of these control measures has sufficed to prevent virus spread. Thus, the best way to reduce geminivirus damage is by breeding crops resistant or tolerant to the virus, either by classical breeding or by genetic engineering. A number of begomoviruses have been the subject of much investigation, due to their severe economic impact. This review considers the most severe viral diseases of four major crops (tomato, bean, cassava and cotton). The approaches taken to breed for resistance to these viral diseases should provide a perspective of the issues involved in breeding for begomovirus resistance in crop plants. [source] The epidemiology of diabetic limb sepsis: an African perspectiveDIABETIC MEDICINE, Issue 11 2002Z. G. Abbas Abstract We review the epidemiology of foot and hand sepsis in adult diabetes patients in Africa. Limb sepsis in these patients is associated with significant morbidity and mortality. The pathogenesis of diabetic foot infections in these patient populations appears to be similar to that for patients in industrialized countries ,ulcers and underlying peripheral neuropathy being the most important risk factors. Prevention of peripheral neuropathy through aggressive glycaemic control may be the most important primary control measure for foot infections. The tropical diabetic hand syndrome (TDHS) is being increasingly seen in diabetes patients in certain parts of Africa. The syndrome is acute, usually follows minor trauma to the hand, and is associated with a progressive synergistic form of gangrene. The major risk factors for TDHS are unknown but recent data suggest poor glycaemic control is associated with poor outcome. Treatment of TDHS requires aggressive surgery. Hence, preventive efforts for both foot and hand sepsis include aggressive glucose control, and education on hand and foot care and the importance of seeking medical attention promptly at the earliest onset of symptoms. Diabet. Med. 19, 895,899 (2002) [source] Rapid review of liquid-based smears as a quality control measureDIAGNOSTIC CYTOPATHOLOGY, Issue 3 2004Sheryl Henderson M.Med.Sc.(Cytol.) Abstract The objective of this study was to investigate the effectiveness of a standardized method of rapid review (RR) of monolayer preparations for the identification of abnormalities, the presence of an endocervical component and infectious agents. A total of 200 ThinPrep (Cytyc, Boxborough, MA) slides representing the spectrum of abnormalities commonly encountered in cervical/vaginal cytologic specimens was retrieved from archive. The study set comprised 129 cases within normal limits (WNL); 36 low-grade epithelial abnormalities (LGEA); 28 high-grade epithelial abnormalities (HGEA), including 2 endocervical adenocarcinomas in situ (AIS) and 7 carcinomas. Eighteen false negative (FN) cases were also included for study. Originally missed on initial review, these cases were found to be abnormal on quality control review (17 LGEA; 1 AIS). Commonly encountered infectious agents were represented and included Candida albicans, Trichomonas vaginalis, herpes simplex virus, and Actinomyces. The slides were reviewed using a standardized method of RR (turret technique, for 60 sec) by three experienced screeners masked to the original reference diagnosis. Median sensitivity for LGEA was 70% (range, 67,72%); HGEA, 69% (range, 54,80%); and FN, 65% (range, 56,78%). Specificity remained high, median specificity for LGEA was 95%; HGEA, 97%; and FN, 100%. There was no significant overcalling of any diagnostic category. The chi-square test at P < 0.05 showed no significant difference between RR and full manual rescreen of the ThinPrep smears in this study. While no statistical difference was proven, the sensitivity measurements for all categories of abnormality were moderate due to the high proportion of atypical cases included into the study set. Abnormalities on the monolayer preparations frequently displayed fewer, smaller groups of disaggregated cells with rounded cytoplasmic outlines that were difficult to discern on RR. Interobserver variation was noted. Monolayers with a paucity of diagnostic cells and those displaying subtle nuclear atypia were often overlooked. Diagn. Cytopathol. 2004;31:141,146. © 2004 Wiley-Liss, Inc. [source] A new saturated/unsaturated model for stormwater infiltration systemsHYDROLOGICAL PROCESSES, Issue 25 2008Dale Browne Abstract Infiltration systems are widely used as an effective urban stormwater control measure. Most design methods and models roughly approximate the complex physical flow processes in these systems using empirical equations and fixed infiltration rates to calculate emptying times from full. Sophisticated variably saturated flow models are available, but rarely applied owing to their complexity. This paper describes the development and testing of an integrated one-dimensional model of flow through the porous storage of a typical infiltration system and surrounding soils. The model accounts for the depth in the storage, surrounding soil moisture conditions and the interaction between the storage and surrounding soil. It is a front-tracking model that innovatively combines a soil-moisture-based solution of Richard's equation for unsaturated flow with piston flow through a saturated zone as well as a reservoir equation for flow through a porous storage. This allows the use of a simple non-iterative numerical solution that can handle ponded infiltration into dry soils. The model is more rigorous than approximate stormwater infiltration system models and could therefore be valuable in everyday practice. A range of test cases commonly used to test soil water flow models for infiltration in unsaturated conditions, drainage from saturation and infiltration under ponded conditions were used to test the model along with an experiment with variable depth in a porous storage over saturated conditions. Results show that the model produces a good fit to the observed data, analytical solutions and Hydrus. Copyright © 2008 John Wiley & Sons, Ltd. [source] The use of riparian vegetated filter strips to reduce river sediment loads: an overestimated control measure?HYDROLOGICAL PROCESSES, Issue 20 2006Gert Verstraeten Abstract The spatially distributed soil erosion and sediment delivery model WATEM/SEDEM was used to simulate the impact of riparian vegetated filter strips (RVFSs) on river sediment delivery at different spatial scales. For a field plot with a straight slope, sediment reduction by the RVFSs is comparable to results obtained through experimental set-ups elsewhere (i.e. >70%). However, at the scale of an entire catchment, sediment reduction is much less (i.e. ±20%) due to (1) overland flow convergence, which reduces the sediment trapping efficiency of an RVFS, and (2) because part of the sediment bypasses the RVFSs through ditches, sewers and road surfaces. These results suggest that, at the catchment scale, RVFSs should be accompanied with other conservation techniques that are more appropriate for reducing river sediment loads, and that also reduce on-site soil erosion. Copyright © 2006 John Wiley & Sons, Ltd. [source] The effects of log erosion barriers on post-fire hydrologic response and sediment yield in small forested watersheds, southern California,HYDROLOGICAL PROCESSES, Issue 15 2001Peter M. Wohlgemuth Abstract Wildfire usually promotes flooding and accelerated erosion in upland watersheds. In the summer of 1999, a high-severity wildfire burned a series of mixed pine/oak headwater catchments in the San Jacinto Mountains of southern California. Log erosion barriers (LEBs) were constructed across much of the burned area as an erosion control measure. We built debris basins in two watersheds, each about 1 ha in area, one with LEBs, the other without, to measure post-fire hydrologic response and sediment yield and to evaluate the effectiveness of the LEBs. The watersheds are underlain by granitic bedrock, producing a loamy sand soil above large extents of weathered bedrock and exposed core stones (tors) on the surface. Measured soil water-repellency was similar over the two catchments. Rain gauges measured 348 mm of precipitation in the first post-fire year. The ephemeral stream channels experienced surface flow after major rainstorms, and the source of the water was throughflow exfiltration at the slope/channel interface. Post-fire overland flow produced some rilling, but hillslope erosion measured in silt fences away from any LEBs was minor, as was sediment accumulation behind the LEBs. Stream channels in the catchments exhibited minor net scour. Water yield was much greater in the LEB-treated watershed. This resulted in 14 times more sediment yield by weight than the untreated watershed. Average soil depths determined by augering were nearly double in the catchment without the LEBs compared with the treated watershed. This suggests that differences in water and sediment yield between the two catchments are due to the twofold difference in the estimated soil water-holding capacity in the untreated watershed. It appears that the deeper soils in the untreated watershed were able to retain most of the precipitation, releasing less water to the channels and thereby reducing erosion and sediment yield. Thus, the test of LEB effectiveness was inconclusive in this study, because soil depth and soil water-holding capacity may have masked their performance. Published in 2001 John Wiley & Sons, Ltd. [source] Effects of culling on spatial associations of Mycobacterium bovis infections in badgers and cattleJOURNAL OF APPLIED ECOLOGY, Issue 5 2007HELEN E JENKINS Summary 1Bovine tuberculosis (TB), caused by Mycobacterium bovis, has serious consequences for Britain's cattle industry. European badgers (Meles meles) can transmit infection to cattle, and for many years the British government culled badgers in a series of attempts to reduce cattle infections. 2We investigated the impact of badger culling on the spatial distribution of M. bovis infection in badger and cattle populations in replicated areas in England. 3M. bovis infection was significantly clustered within badger populations, but clustering was reduced when culls were repeated across wide areas. A significant spatial association between M. bovis infections in badgers and cattle herds likewise declined across successive culls. These patterns are consistent with evidence that badgers are less territorial and range more widely in culled areas, allowing transmission to occur over greater distances. 4Prior to culling, M. bovis infections were clustered within cattle populations. Where badger culling was localised, and in unculled areas just outside widespread culling areas, cattle infections became less spatially clustered as badger culling was repeated. This is consistent with expanded badger ranging observed in these areas. 5In contrast, clustering of infection in cattle persisted over time on lands where badgers were repeatedly culled over wide areas. While this lack of a temporal trend must be interpreted with caution, it might reflect persistent infection within, and continued transmission between, cattle herds in areas where transmission from badgers to cattle had been reduced by badger culling. Continued spatial association of infections in cattle and badgers in such areas might partly reflect transmission from cattle. 6Synthesis and applications: Our findings confirm that badger culling can prompt spatial spread of M. bovis infection, a phenomenon likely to undermine the utility of this approach as a disease control measure. Possible evidence of transmission from cattle, both to other cattle and to badgers, suggests that improved cattle controls might yield multiple benefits for TB management. [source] Managing risk through a flexible recipe frameworkAICHE JOURNAL, Issue 3 2008Sergio Ferrer-Nadal Abstract A novel approach is proposed that exploits the use of a flexible recipe framework as a better way to handle the risk associated with the scheduling under uncertainty of batch chemical plants. The proposed solution strategy relies on a novel two-stage stochastic formulation that explicitly includes the trade-off between risk and profit at the decision-making level. The model uses a continuous-time domain representation and the generalized notion of precedence. Management of risk is explicitly addressed by including a control measure (i.e., the profit in the worst scenario), as an additional objective to be considered, thus, leading to a multiobjective optimization problem. To overcome the numerical difficulties associated with such mathematical formulation, a decomposition strategy based on the sample average approximation (SAA) is introduced. The main advantages of this approach are illustrated through a case study, in which a set of solutions appealing to decision makers with different attitudes toward risk are obtained. The potential benefits of the proposed flexible recipe framework as a way of managing the risk associated with the plant operation under demand uncertainty are highlighted through comparison with the conventional approach that considers nominal operating conditions. Numerical results corroborate the advantages of exploiting the capabilities of the proposed flexible recipe framework for risk management purposes. © 2008 American Institute of Chemical Engineers AIChE J, 2008 [source] Assessing the impacts and potential control of terrestrial plant colonization of a reservoir bed during an extreme drawdown eventLAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 1 2009A. Boulding Abstract Extended periods of drawdown of reservoirs can result in the ,terrestrialization' of the lake bottom sediments, which describes the process whereby the exposed dry sediment takes on soil-like qualities. Opportunistic colonization of lake bed by terrestrial plants can occur under such conditions. A survey of plant communities of a large reservoir (Lake Hume) following its extreme drawdown, resulted in significant quantities of carbon, nitrogen and phosphorus being bound up in the terrestrial vegetation that colonized the lake bed. The phosphorus uptake from the sediment into plant material particularly could represent a significant pathway for phosphorus re-mobilization back into the lake. The potential of using stock grazing as a control measure for mitigating the effects of terrestrial plant colonization is also discussed. [source] Role of Alicyclobacillus acidoterrestris in the development of a disinfectant taint in shelf-stable fruit juiceLETTERS IN APPLIED MICROBIOLOGY, Issue 1 2003N. Jensen Abstract Aims: This study was undertaken to identify the bacterium and metabolic products contributing to a disinfectant taint in shelf-stable fruit juice and to determine some of the growth conditions for the organism. Methods and Results: Microbiological examination of tainted and untainted fruit juice drinks detected low numbers of acid-dependent, thermotolerant, spore-forming bacteria in the tainted juices only. The presence of ,-cyclohexyl fatty acids was confirmed in two of the isolates by cell membrane fatty acid analysis. The isolates were subsequently identified as Alicyclobacillus acidoterrestris by partial 16S rDNA sequencing. Studies on the isolates showed growth at pH 2·5,6·0 and 19·5,58 °C. Gas chromatography/mass spectrometry (GC/MS) was used to identify and quantify 2,6-dibromophenol (2,6-DBP) and 2,6-dichlorophenol (2,6-DCP) in the tainted juice. Challenge studies in a mixed fruit drink inoculated with the two isolates and the type strain of A. acidoterrestris, incubated at 44,46 °C for 4 d, showed the production of both metabolites, which were confirmed and quantified by GC/MS. Conclusions: The results show that A. acidoterrestris can produce 2,6-DBP and 2,6-DCP in shelf-stable juices. Significance and Impact of the Study: This is the first report detailing experimental methodology showing that A. acidoterrestris can produce 2,6-DCP in foods. Control of storage temperatures (to <,20 °C) immediately after processing may provide an effective control measure for the fruit juice industry to prevent spoilage by A. acidoterrestris. [source] Diversity in fertility patterns in GuatemalaPOPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 6 2006Sofie De Broe Abstract This study investigates urban and rural fertility trends in Guatemala up to 2002. It also aims to establish, using the theory of diffusion as its theoretical framework, the extent to which ethnicity and ethnic diversity are associated with geographical patterns in local-level fertility after controlling for socio-economic indicators. Data from the Demographic and Health Surveys of 1987, 1995,96 and 1998,99, the National Maternal and Child Health Survey of 2002 and the Census of 2002 were used. P/F ratios were calculated and used as an analytical tool and quality control measure of the data in order to establish the timing of changes in fertility patterns as measured by age-specific fertility rates (ASFRs) based on exact exposure in four-year periods from 1972 to 2002. Finally, the 2002 census data were used to analyse and model fertility at the municipio- level using ordinary least squares regression. The results suggest a steady but very slow decline in fertility from 1972 until the mid-1990s. Both the P/F ratios and ASFRs calculated using the Maternal and Child Health Survey and Census of 2002 show a sharp decline in fertility since 1998. The regression results for the census data suggest an independent and significant effect of ,proportion of indigenous people' and an almost significant effect of ethnic diversity on fertility at the municipio -level. The very slow decline in fertility in Guatemala until fairly recently can be attributed to the fact that Guatemala has been lagging behind in terms of socio-economic development and the additional challenge of having a culturally very diverse and segregated population, preventing the spread of modern reproductive ideas and behaviour. The accelerated fertility decline since the end of the 1990s seems likely to be associated with the widespread availability and increased uptake of family planning following declining fertility desires among its indigenous population. Copyright © 2006 John Wiley & Sons, Ltd. [source] The Power of Networks: Integration and Financial Cooperative PerformanceANNALS OF PUBLIC AND COOPERATIVE ECONOMICS, Issue 3 2005by Martin Desrochers We develop a classification scheme based on a theoretical framework that builds on published work using transaction cost economics (TCE) to explain integration of large numbers of financial cooperatives into networks. We identify three critical levels of increasing integration we call respectively atomized systems, consensual networks and strategic networks. Further, we test some of the propositions that result from the theoretical framework on an international sample of financial cooperative systems. Based on this analysis we can conclude that: (i) Integration is less (more) important in developing (more developed) countries and for very small (large) financial cooperatives as a determinant of efficiency. However, integration tends to reduce volatility of efficiency and performance regardless of development. (ii) Integration appears to help control measure of managers' expense preferences that tend to affect performance of FC. (iii) Despite high costs of running hub-like organizations in highly integrated system, these systems economize in bounded rationality and operate at lower costs than less integrated systems. [source] Evaluation of a dynamic multi-class sediment transport model in a catchment under soil-conservation agricultureEARTH SURFACE PROCESSES AND LANDFORMS, Issue 11 2008Peter Fiener Abstract Soil erosion models are essential tools for the successful implementation of effective and adapted soil conservation measures on agricultural land. Therefore, models are needed that predict sediment delivery and quality, give a good spatial representation of erosion and deposition and allow us to account for various soil conservation measures. Here, we evaluate how well a modified version of the spatially distributed multi-class sediment transport model (MCST) simulates the effectiveness of control measures for different event sizes. We use 8 year runoff and sediment delivery data from two small agricultural watersheds (0·7 and 3·7 ha) under optimized soil conservation. The modified MCST model successfully simulates surface runoff and sediment delivery from both watersheds; one of which was dominated by sheet and the other was partly affected by rill erosion. Moreover, first results of modelling enrichment of clay in sediment delivery are promising, showing the potential of MCST to model sediment enrichment and nutrient transport. In general, our results and those of an earlier modelling exercise in the Belgian Loess Belt indicate the potential of the MCST model to evaluate soil erosion and deposition under different agricultural land uses. As the model explicitly takes into account the dominant effects of soil-conservation agriculture, it should be successfully applicable for soil-conservation planning/evaluation in other environments. Copyright © 2008 John Wiley & Sons, Ltd. [source] Evolution of channel morphology and hydrologic response in an urbanizing drainage basinEARTH SURFACE PROCESSES AND LANDFORMS, Issue 9 2006Peter A. Nelson Abstract The Dead Run catchment in Baltimore County, Maryland, has undergone intense urbanization since the late 1950s. Reconstruction of the channel planform from topographic maps dating back to the 1890s and aerial photographs dating back to the 1930s indicates that the channel has remained stable in planform since at least the 1930s. The relative stability of Dead Run contrasts with the alterations in channel morphology reported for other urbanizing streams in the Piedmont physiographic province of the eastern United States. Trend analyses of discharge records in Dead Run show that urban development and stormwater control measures have had significant impacts on the hydrologic response of the catchment. The flood hydraulics of the Dead Run catchment are examined for the event that occurred on 22 June 1972 in association with Hurricane Agnes. A two-dimensional hydraulic model, TELEMAC-2D, was used with a finite-element mesh constructed from a combination of high-resolution LiDAR topographic data and detailed field survey data to analyse the distribution of boundary shear stress and unit stream power along the channel and floodplain during flooding from Hurricane Agnes. The spatial and temporal distributions of these parameters, relative to channel gradient and channel/valley bottom geometry, provide valuable insights on the stability of the Dean Run channel. The stability of Dead Run's channel planform, in spite of extreme flooding and decades of urban development, is most likely linked to geological controls of channel and floodplain morphology. Copyright © 2006 John Wiley & Sons, Ltd. [source] Seasonality and the dynamics of infectious diseasesECOLOGY LETTERS, Issue 4 2006Sonia Altizer Abstract Seasonal variations in temperature, rainfall and resource availability are ubiquitous and can exert strong pressures on population dynamics. Infectious diseases provide some of the best-studied examples of the role of seasonality in shaping population fluctuations. In this paper, we review examples from human and wildlife disease systems to illustrate the challenges inherent in understanding the mechanisms and impacts of seasonal environmental drivers. Empirical evidence points to several biologically distinct mechanisms by which seasonality can impact host,pathogen interactions, including seasonal changes in host social behaviour and contact rates, variation in encounters with infective stages in the environment, annual pulses of host births and deaths and changes in host immune defences. Mathematical models and field observations show that the strength and mechanisms of seasonality can alter the spread and persistence of infectious diseases, and that population-level responses can range from simple annual cycles to more complex multiyear fluctuations. From an applied perspective, understanding the timing and causes of seasonality offers important insights into how parasite,host systems operate, how and when parasite control measures should be applied, and how disease risks will respond to anthropogenic climate change and altered patterns of seasonality. Finally, by focusing on well-studied examples of infectious diseases, we hope to highlight general insights that are relevant to other ecological interactions. [source] Postflood movements and population connectivity in gambusia (Gambusia holbrooki)ECOLOGY OF FRESHWATER FISH, Issue 4 2006P. Chapman Abstract , A population of the exotic pest fish Gambusia holbrooki inhabiting a drainage channel was sampled regularly to record responses to flooding and subsequent population reestablishment. The flood reduced numbers in the channel to near-zero levels. After remaining very low for 2 months, densities increased steadily through juvenile recruitment and the concentration of fish in drying pools. Tagging revealed that in general, movements between pools separated by only a few metres were relatively limited. There was evidence for habitat segregation and population subdivision, as fish from different pools varied markedly in terms of mean population density, movement behaviour, sex and size composition and juvenile recruitment. The most favoured pool was relatively deep, well lit and had the greatest habitat diversity. Gambusia control measures are likely to be most effective if timed to coincide with floods (which reduce local population densities) and/or droughts (which concentrate fish and allow targeting of source populations). [source] Periodontal infection control: current clinical conceptsENDODONTIC TOPICS, Issue 1 2006JAN L. WENNSTRÖM The main objective of the treatment of patients with periodontitis is to establish adequate infection control in the dentogingival area. Pocket/root instrumentation (scaling and root planing), combined with effective self-performed supragingival plaque control measures, constitute the basic treatment modalities, but also locally applied antiseptics and antibiotics may be utilized. The purpose of this article is to give an overview of current clinical concepts on periodontal infection control. [source] Phenological model of pear psylla Cacopsylla pyriENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2005L. Schaub Abstract A phenological model of first- and second-generation pear psylla, Cacopsylla pyri L. (Homoptera: Psyllidae), was developed. The model included a time-distributed delay and was based on authors' observations and literature data of termination of reproductive diapause, oviposition-period length, and developmental duration of juvenile stages depending on temperature. After calibrating microclimate, the model provided a good simulation of observations from different orchards in Switzerland and Italy over several years. The model or simulated output tables can be used to improve timing of monitoring and control measures. [source] Prevalence and correlates of purchasing contraband cigarettes on First Nations reserves in Ontario, CanadaADDICTION, Issue 3 2009Rita Luk ABSTRACT Aims Non-First Nations people purchasing cigarettes on First Nations reserves do not pay applicable taxes. We estimated prevalence and identified correlates of purchasing contraband cigarettes on reserves; we also quantified the share of contraband purchased on reserves relative to reported total cigarette consumption and the associated financial impact on taxation revenue. Design Data from the Ontario Tobacco Survey, a regionally stratified representative population telephone survey that over-samples smokers. Setting Ontario, Canada. Participants A total of 1382 adult current smokers. Measurements Reported status of purchasing cigarettes on reserves and the quantity of cigarettes bought on reserves. The prevalence of purchasing cigarettes on reserves was assessed with descriptive statistics. A two-part model was used to analyse correlates of having recently purchased contraband. Findings A total of 25.8% reported recent purchasing and 11.5% reported usual purchasing. Heavy smoking, having no plans to quit and lower education were correlated with recent purchasing. Heavy smoking and not having plans to quit were also correlated with buying more packs of cigarettes on reserves. Contraband purchases on reserves accounted for 14.0% of the reported total cigarette consumption and resulted in an estimated tax loss of $122.2 million. Conclusions There was substantial purchasing of contraband cigarettes on reserves in Ontario, resulting in significant losses in tax revenues. The availability of these cheap cigarettes undermines the effectiveness of tobacco taxation to reduce smoking. Wherever indicated, governments should strengthen their contraband prevention and control measures, as recommended by the Framework Convention on Tobacco Control, to ensure that tobacco taxation achieves its intended health benefits and that tax revenues are protected. [source] Monitoring pyrethroid resistance in field collected Blattella germanica Linn. (Dictyoptera: Blattellidae) in IndonesiaENTOMOLOGICAL RESEARCH, Issue 2 2009Intan AHMAD Abstract The German cockroach, Blattella germanica, is a major and the most common pest in public areas in Indonesia. Although intensive control measures have been carried out to control the populations of this pest, results have been far from successful, which is believed to be because of its resistance to insecticides. A standard World Health Organization (WHO) glass jar test was carried out to determine the resistance level of this insect to pyrethroid insecticides, the most commonly used insecticides for cockroach control in Indonesia. A susceptible S1 strain collected from Tembagapura Papua was compared with four strains collected from Bandung, West Java: strain S2, from a local restaurant; strain S3, from the Bandung train station; and strains S4 and S5, from two different hotels. All strains showed low resistance to the pyrethroid, except the S5 strain, which had a Resistance Ratio (RR)50 of 95 for permethrin. The addition of piperonyl butoxide (PBO) suggests that the detoxifying enzyme mixed function oxidases (MFO) played an important role in the development of resistance to permethrin in the S5 strain, suggested by the high Synergist Ratio (SR) of 70.4. However, the low level of resistance to cypermethrin was not affected by PBO, suggesting that other mechanisms of pyrethroid resistance are involved. Our study is the first report of German cockroach resistance to permethrin in Indonesia, and the findings can be used in formulating potential strategies for cockroach resistance management. [source] Graphium agamemnon Linnaeus (Lepidoptera: Papilionidae), a pest of soursop (Annona muricata Linnaeus), in Vietnam: Biology and a novel method of controlENTOMOLOGICAL RESEARCH, Issue 2 2008Nga Thi VU Abstract Few butterflies are pests of economic significance, but some may be locally destructive, such as the papilionid Graphium agamemnon Linnaeus, which is known to feed on the commercially important soursop (Annona muricata Linnaeus) in Vietnam. This paper documents the life history and ecology of G. agamemnon and investigates commonly used control measures in south-east Vietnam. A novel method of controlling G. agamemnon infestation is described. If soursop basal rootstock (Annona glabra Linnaeus) is encouraged to shoot during times of peak butterfly activity, ovipositing G. agamemnon females are preferentially attracted to the new growth where the resulting early stages may be easily detected and removed by hand. [source] Synergist efficacy of piperonyl butoxide with deltamethrin as pyrethroid insecticide on Culex tritaeniorhynchus (Diptera: Culicidae) and other mosquitoe speciesENVIRONMENTAL TOXICOLOGY, Issue 1 2009M. R. Fakoorziba Abstract Continuous and indiscriminate use of pesticides, especially in tropical countries for public health or agriculture purpose, has led many vector populations to become resistant to organochlorides, organophosphates, and even to carbamates and pyrethroids. Development of resistance by a vector population has been one of the reasons for the failure of the control measures in many countries. This investigation demonstrates the efficacy of piperonyl-butoxide (PBO) with deltamethrin, as pyrethroid insecticide, against the field-collected mosquitoe larvae of five species, Aedes aegypti, Anopheles culicifacies, An. stephensi, An. vagus, and Culex quinqufasciatus, and two morphological variants of Cx. tritaeniorhynchus (type A from grand pools of Mysore city and type B from rice fields of Mandya district). For testing the synergistic effect of PBO, stock solutions of deltamethrin and PBO were mixed in 1:6 ratio. The synergistic ratio and the percent suppression in deltamethrin tolerance were calculated by using LC50 values. From the results, it is clear that, PBO is an effective synergist with deltamethrin against all of species undertaken in this investigation. So, it is suggested that PBO is a good synergist in this area for decreasing the use of pesticides in environment in vector control. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2009. [source] Review of carrot fly control in Northern Europe , 2009,EPPO BULLETIN, Issue 2 2009R. Collier In February 2009, the European and Mediterranean Plant Protection Organization (EPPO) held a workshop to discuss the management of carrot fly (Psila rosae) within Europe. Prior to the workshop, participants completed a questionnaire about carrot fly and current control methods and some of the information is summarised in this paper. In general, this pest is controlled adequately at present, but there is a heavy reliance on insecticides. The responses to the questionnaire highlighted a number of issues, in particular: the limited range and efficacy of the insecticides available at present, concerns about the availability of effective control measures in the future and a need for improvements in the targeting of treatments through forecasting and monitoring and the use of treatment thresholds. [source] Regulatory measures against Erwinia amylovora in Switzerland,EPPO BULLETIN, Issue 2 2005B. Duffy Switzerland joined the list of fireblight-affected European countries in 1989. Vigorous and systematic steps were taken to limit the impact of the disease on fruit production and amenity plants. These efforts are codified in a Swiss law detailing prevention, eradication, control measures and issues of compensation. As with many Swiss legal directives, there is a defined coordination of federal and cantonal responsibilities and, in the case of fireblight, there is also an emphasis at all levels on personal responsibility of owners of susceptible objects (e.g. nurseries, orchards, host plants). Extension activities have been a key component in achieving compliance with disease management regulations and in obtained public support for control efforts. Agroscope FAW Wädenswil has taken a leading role in this respect through its website http://www.feuerbrand.ch. [source] Bio-economic modelling of potato brown rot in the Netherlands,EPPO BULLETIN, Issue 3 2003A. Breukers A research project is being undertaken to design a bio-economic model of potato brown rot (Ralstonia solanacearum) in the Netherlands. The first part of the project consists of an analysis of the past and current brown rot policy for its effectiveness and costs. Then, a stochastic, bio-economic model will be designed that shows the relationship between the costs of control measures and their effect on the probability of brown rot. This model will eventually be used to determine optimal control strategies and to make recommendations for improvement of the Dutch brown rot policy. [source] Structure and organization of warning services in Rheinland-Pfalz (Germany),EPPO BULLETIN, Issue 1 2000E. Jörg Rheinland-Pfalz, a federal state in the south-western part of Germany, is an agricultural region with high crop diversity. For each branch of agriculture (arable, fruits, vegetables and ornamental plants), specific warning and information services have been installed. Advisory work, including warning services, is done by a central (LPP) and eight regional state institutions (SL V As). LPP provides the infrastructure for information dissemination, organizes data acquisition and supplies the farmers with general information on crop protection (availability of plant protection products, control strategies, etc.), SL V As collect data on current pest development and elaborate regional recommendations on field assessments and control measures to be taken by the farmers. Warning service information is transmitted to the farmers by info post (periodic letters), telephone-answering machines, fax services and, lately, via the Internet. Farmers are mainly interested in current disease and pest severity data, preferably on a local basis, to aid their decision-making in crop protection. The forecasting models and computer-aided decision-support systems run by the state crop protection service have become essential tools during the last four years. Their results, supplemented by field-monitoring data, serve as the main input for the warning services. The Internet, in conjunction with computerized decision-support systems, provides the means of ensuring an adequate supply of warning service information at a time when crop protection services are undergoing severe staff reductions. [source] | ||||||||||||||||||||||||||||