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Large Impact (large + impact)
Selected AbstractsPerfusion-based functional magnetic resonance imaging,CONCEPTS IN MAGNETIC RESONANCE, Issue 1 2003Afonso C. Silva Abstract The measurement of cerebral blood flow (CBF) is a very important way of assessing tissue viability, metabolism, and function. CBF can be measured noninvasively with magnetic resonance imaging (MRI) by using arterial water as a perfusion tracer. Because of the tight coupling between neural activity and CBF, functional MRI (fMRI) techniques are having a large impact in defining regions of the brain that are activated due to specific stimuli. Among the different fMRI techniques, CBF-based fMRI has the advantages of being specific to tissue signal change, a critical feature for quantitative measurements within and across subjects, and for high-resolution functional mapping. Unlike the conventional blood oxygenation level dependent (BOLD) technique, the CBF change is an excellent index of the magnitude of neural activity change. Thus, CBF-based fMRI is the tool of choice for longitudinal functional imaging studies. A review of the principles and theoretical backgrounds of both continuous and pulsed arterial spin labeling methods for measuring CBF is presented, and a general overview of their current applications in the field of functional brain mapping is provided. In particular, examples of the use of CBF-based fMRI to investigate the fundamental hemodynamic responses induced by neural activity and to determine the signal source of the most commonly used BOLD functional imaging are reviewed. © 2003 Wiley Periodicals, Inc. Concepts Magn Reson 16A: 16,27, 2003 [source] Characterization of voltage degradation in dynamic field gradient focusingELECTROPHORESIS, Issue 5 2008Jeffrey M. Burke Abstract Dynamic field gradient focusing (DFGF) is an equilibrium gradient method that utilizes an electric field gradient to simultaneously separate and concentrate charged analytes based on their individual electrophoretic mobilities. This work describes the use of a 2-D nonlinear, numerical simulation to examine the impact of voltage loss from the electrodes to the separation channel, termed voltage degradation, and distortions in the electric field on the performance of DFGF. One of the design parameters that has a large impact on the degree of voltage degradation is the placement of the electrodes in relation to the separation channel. The simulation shows that a distance of about 3,mm from the electrodes to the separation channel gives the electric field profile with least amount of voltage degradation. The simulation was also used to describe the elution of focused protein peaks. The simulation shows that elution under constant electric field gradient gives better performance than elution through shallowing of the electric field. Qualitative agreement between the numerical simulation and experimental results is shown. The simulation also illustrates that the presence of a defocusing region at the cathodic end of the separation channel causes peak dispersion during elution. The numerical model is then used to design a system that does not suffer from a defocusing region. Peaks eluted under this design experienced no band broadening in our simulations. Preliminary experimental results using the redesigned chamber are shown. [source] Shareholder Wealth Effects of European Domestic and Cross-border Takeover BidsEUROPEAN FINANCIAL MANAGEMENT, Issue 1 2004Marc Goergen G32; G34 Abstract This paper analyses the short-term wealth effects of large intra-European takeover bids. We find announcement effects of 9% for the target firms compared to a statistically significant announcement effect of only 0.7% for the bidders. The type of takeover bid has a large impact on the short-term wealth effects with hostile takeovers triggering substantially larger price reactions than friendly operations. When a UK firm is involved, the abnormal returns are higher than those of bids involving both a Continental European target and bidder. There is strong evidence that the means of payment in an offer has an impact on the share price. A high market-to-book ratio of the target leads to a higher bid premium, but triggers a negative price reaction for the bidding firm. We also investigate whether the predominant reason for takeovers is synergies, agency problems or managerial hubris. Our results suggest that synergies are the prime motivation for bids and that targets and bidders share the wealth gains. [source] Increase in the fracture toughness and bond energy of clay by a root exudateEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 5 2008B. Zhang Summary Root exudates help drive the formation of the rhizosphere by binding soil particles, but the underlying physical mechanisms have not been quantified. This was addressed by measuring the impact of a major component of root exudates, polygalacturonic acid (PGA), on the interparticle bond energy and fracture toughness of clay. Pure kaolinite was mixed with 0, 1.2, 2.4, 4.9 or 12.2 g PGA kg,1 to form test specimens. Half of the specimens were washed repeatedly to remove unbound PGA and evaluate the persistence of the effects, similar to weathering in natural soils. Fracture toughness, KIC, increased exponentially with added PGA, with washing increasing this trend. In unwashed specimens KIC ranged from 54.3 ± 2.5 kPa m,1/2 for 0 g PGA kg,1 to 86.9 ± 4.7 kPa m,1/2 for 12.2 g PGA kg,1. Washing increased KIC to 61.3 ± 1.2 kPa m,1/2 for 0 g PGA kg,1 and 132.1 ± 4.9 kPa m,1/2 for 12.2 g PGA kg,1. The apparent bond energy, ,, of the fracture surface increased from 5.9 ± 0.6 J m,2 for 0 g kg,1 to 12.0 ± 1.1 J m,2 for 12.2 g kg,1 PGA in the unwashed specimens. The washed specimens had , of 13.0 ± 1.9 J m,2 for 0 g kg,1 and 21.3 ± 2.6 J m,2 for 12.2 g PGA kg,1. Thus PGA, a major component of root exudates, has a large impact on the fracture toughness and bond energy of clay, and is likely to be a major determinant in the formation of the rhizosphere. This quantification of the thermodynamics of fracture will be useful for modelling rhizosphere formation and stability. [source] Price Movers on the Stock Exchange of Thailand: Evidence from a Fully Automated Order-Driven MarketFINANCIAL REVIEW, Issue 3 2010Charlie Charoenwong G12; G14; G15 Abstract This study examines which trade sizes move stock prices on the Stock Exchange of Thailand (SET), a pure limit order market, over two distinct market conditions of bull and bear. Using intraday data, the study finds that large-sized trades (i.e., those larger than the 75th percentile) account for a disproportionately large impact on changes in traded and quoted prices. The finding remains even after it has been subjected to a battery of robustness checks. In contrast, the results of studies conducted in the United States show that informed traders employ trade sizes falling between the 40th and 95th percentiles (Barclay and Warner, 1993; Chakravarty, 2001). Our results support the hypothesis that informed traders in a pure limit order market, such as the SET, where there are no market makers, also use larger-size trades than those employed by informed traders in the United States. [source] Towards a multi-criteria approach for priority setting: an application to GhanaHEALTH ECONOMICS, Issue 7 2006Rob Baltussen Abstract Background: Many criteria have been proposed to guide priority setting in health, but their relative importance has not yet been determined in a way that allows a rank ordering of interventions. Methods: In an explorative study, a discrete choice experiment was carried out to determine the relative importance of different criteria in identifying priority interventions in Ghana. Thirty respondents chose between 12 pairs of scenarios that described interventions in terms of medical and non-medical criteria. Subsequently, a composite league table was constructed to rank order a set of interventions by mapping interventions on those criteria and considering the relative weights of different criteria. Results: Interventions that are cost-effective, reduce poverty, target severe diseases, or target the young had a higher probability of being chosen than others. The composite league table showed that high priority interventions in Ghana are prevention of mother to child transmission in HIV/AIDS control, and treatment of pneumonia and diarrhoea in childhood. Low priority interventions are certain interventions to control blood pressure, tobacco and alcohol abuse. The composite league table lead to a different and more differentiated rank ordering of interventions compared to pure efficiency ratings. Conclusion: This explorative study has introduced a multi-criteria approach to priority setting. It has shown the feasibility of accounting for efficiency, equity and other societal concerns in prioritization decisions, and its potentially large impact on priority setting. Copyright © 2006 John Wiley & Sons, Ltd. [source] A spatially advancing turbulent flow and heat transfer in a curved channelHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 1 2010Koji Matsubara Abstract Direct numerical simulation was performed for a spatially advancing turbulent flow and heat transfer in a two-dimensional curved channel, where one wall was heated to a constant temperature and the other wall was cooled to a different constant temperature. In the simulation, fully developed flow and temperature from the straight-channel driver was passed through the inlet of the curved-channel domain. The frictional Reynolds number was assigned 150, and the Prandtl number was given 0.71. Since the flow field was examined in the previous paper, the thermal features are mainly targeted in this paper. The turbulent heat flux showed trends consistent with a growing process of large-scale vortices. In the curved part, the wall-normal component of the turbulent heat flux was twice as large as the counterpart in the straight part, suggesting active heat transport of large-scale vortices. In the inner side of the same section, temperature fluctuation was abnormally large compared with the modest fluctuation of the wall-normal velocity. This was caused by the combined effect of the large-scale motion of the vortices and the wide variation of the mean temperature; in such a temperature distribution, large-scale ejection of the hot fluid near the outer wall, which is transported into the near inner-wall region, should have a large impact on the thermal boundary layer near the inner wall. Wave number decomposition was conducted for various statistics, which showed that the contribution of the large-scale vortex to the total turbulent heat flux normal to the wall reached roughly 80% inside the channel 135° downstream from the curved-channel inlet. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20275 [source] Causes of variability in the summertime Antarctic boundary-layer climateINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 13 2007Dirk van As Abstract A high-resolution one-dimensional atmospheric model is used to assess the contribution of various surface characteristics and external forcings on the structure and dynamics of the atmospheric boundary layer (ABL) over the Antarctic Plateau in summer. The reference run simulates the boundary layer over a mildly sloping surface (1.5 m km,1) for a clear sky near the end of the Antarctic summer (31 January-3 February). The ABL depth is approximately 100 m. At night, a low-level jet forms due to the combined effect of katabatic forcing and an inertial oscillation. During the day a convective mixed layer is present. As expected, the ABL is very sensitive to surface slope; a larger slope forces higher wind speeds and a deeper boundary layer. Over a horizontal surface, a nocturnal jet is also found as a result of the inertial oscillation. A modest change in surface albedo alters the mixed-layer temperature and the height and strength of the nocturnal jet considerably. Rotating the large-scale wind relative to the slope direction also has a large impact on ABL depth and structure. The deepest boundary layer and largest wind speed over a northward down-sloping surface are found for an easterly (cross slope) large-scale wind, as is typical for Antarctica. A very shallow ABL with low wind speed is found for the opposite large-scale wind direction. ABL sensitivity to surface roughness was found to be small. For all experiments, the ABL sensitivity is enhanced due to the positive feedback between the cooling of the ABL and katabatic wind speed. Copyright © 2007 Royal Meteorological Society [source] Detection of a possible change point in atmospheric variability in the North Atlantic and its effect on Scandinavian glacier mass balanceINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 14 2005Rowan Fealy Abstract Climate change, resulting from an increase in global temperatures, is likely to have a large impact on glaciers and glacier meltwater during the course of the present century resulting in significant contributions to sea level rise. Globally, glaciers are in retreat, partly as a response to the return to warmer conditions after the last neoglacial period during the Little Ice Age but also because of the almost continuous increases evident in global temperature since then. In contrast, Scandinavian glaciers, particularly maritime glaciers, were maintaining equilibrium or advancing over the closing decades of the last century possibly resulting from an increased moisture flux over the North Atlantic. While the more continental glaciers were still declining, the rate of decline diminished during the late 1980s. This coincides with an accelerated rate of increase evident on the maritime glaciers in southwestern Norway. A change point in atmospheric variability in the North Atlantic is identified as having occurred during this period. This change point is associated with an intensification of westerlies over Europe, particularly since the late 1980s, which significantly contributes to increases in temperature and precipitation over northern Europe while suppressing the penetration of warm, moist air into more southern European locations. Regional variations in temperature and precipitation from selected Scandinavian stations are also found to be consistent with the changes in the large-scale modes of atmospheric variability in the North Atlantic. Copyright © 2005 Royal Meteorological Society [source] Roadside conditions as predictor for wildlife crossing probability in a Central African rainforestAFRICAN JOURNAL OF ECOLOGY, Issue 2 2010Christiaan A. Van Der Hoeven Abstract The negative effects of roads on wildlife in tropical rainforests are poorly understood. Road construction has high priority in Africa, while negative impacts of roads on wildlife movement often are neglected. This study aims at providing information on the effects of roads on crossing behaviour of rainforest wildlife. The probability that wildlife would cross forest roads was analysed for association with ten different factors that were linked to road presence or construction. Factors were divided into three classes: vegetation cover, topography and human influence. A trackplot survey was done in southern Cameroon, Africa. Trackplots were laid along a 32 km unpaved logging road that intersects Campo-Ma'an National Park. Tracks of several species were found frequently (e.g. genets and porcupines); while others were found only sporadically (e.g. forest duikers and apes). The actual physical obstacles found along the road (e.g. logs, banks, etc.) were highly negatively correlated with crossing probabilities. For all wildlife species high vegetation cover was positively correlated to crossing probability. This study indicates that roads have a large impact on wildlife, and suggests which factors could be altered during road construction and maintenance in order to mitigate these impacts. Résumé Les effets négatifs des routes sur la faune sauvage des forêts tropicales sont mal compris. La construction de routes est une toute grande priorité en Afrique mais on néglige souvent les impacts négatifs des routes sur les déplacements de la faune. Cette étude cherche à fournir des informations sur les effets des routes sur les animaux des forêts pluviales qui les traversent. Nous avons analysé la probabilité que la faune traverse les routes en fonction de dix facteurs différents liés à la présence ou à la construction de routes. Ces facteurs furent divisés en trois classes: couverture végétale, topographie et influence humaine. Des parcelles échantillons furent définies dans le sud du Cameroun, Afrique pour y déceler les traces. Ces parcelles se trouvaient le long d'une piste forestière non macadamisée qui traverse le Parc National de Campo-Ma'an. On a souvent observé des traces de plusieurs espèces (ex. genettes et porcs-épics) alors que d'autres (ex. céphalophes de forêt et grands singes) ne se voyaient que sporadiquement. Les obstacles physiques rencontrés le long de la route (ex. troncs, remblais, etc.) étaient en forte corrélation négative avec la probabilité de traverser. Pour toutes les espèces sauvages, une végétation dense était positivement liée à la probabilité de traverser. Cette étude indique que les routes ont un grand impact sur la faune sauvage et indique quels facteurs pourraient être modifiés lors de la construction et de l'entretien des routes pour atténuer ces impacts. [source] SOX 404 and ERM: Perfect partners , or not?JOURNAL OF CORPORATE ACCOUNTING & FINANCE, Issue 3 2007Jeffrey C. Thomson The Sarbanes-Oxley Act (SOX) Section 404 regulations and guidance have had a large impact on the adoption of enterprise risk management (ERM) in the United States. In the short run, SOX 404 has impeded the adoption of risk-based approaches because of its rules that are totally counter to a holistic, risk-based approach. In the longer run, SOX provides an opportunity for even faster adoption of ERM,but only if there is more radical thinking on the part of regulators and practitioners alike in training, education, and certification of this body of knowledge. © 2007 Wiley Periodicals, Inc. [source] Population dynamics in Digitalis purpurea: the interaction of disturbance and seed bank dynamicsJOURNAL OF ECOLOGY, Issue 6 2007NINA SLETVOLD Summary 1Plant ecologists have long since realized that the persistence of many facultative biennial plants depends upon disturbance. However, we still have a limited knowledge of the population-level effects of disturbance, and the connection between adult and seed bank dynamics. 2Using data from a 3-year demographic study combined with experimental gap-opening in a large population of Digitalis purpurea, we parameterized stochastic transition matrix models in ,disturbed' vs. ,undisturbed' areas. We simulated different gap sizes (fraction of population that was disturbed) and temporal disturbance patterns (constant, random, regular and irregular return intervals) and evaluated the effects on population growth rate and seed bank dynamics. To explore seed bank importance we used two alternatives for seed bank survival rate (0.75/0.35) and three alternatives for seed bank recruitment fraction (0.9/0.5/0.1). 3Observed background recruitment levels were insufficient to ensure a positive population growth rate. Increased amounts of gap-opening led to higher growth rates, and population persistence was predicted at moderate disturbance levels if seed bank survival was high (0.75). 4Temporal disturbance pattern affected model results; random and interval scenarios resulted in lower population growth rates and higher extinction risks than constant scenarios of the same average disturbance level. Small and frequent disturbances led to considerably higher growth rates than large and rare disturbances. 5Stochastic elasticity analyses identified the seed bank as the most important life cycle stage with respect to population growth and persistence in most scenarios, and its relative impact was positively related to seed bank survival rate and negatively related to disturbance level. Variation in the recruitment fraction from seed bank vs. seed rain affected both population growth rate and elasticity patterns, indicating the large impact of spatial variation in seed bank density. 6Synthesis: Despite the existence of a large seed bank, our data suggest that recruitment may be locally seed-limited due to a patchy seed bank structure. Local population development may consequently differ widely from gap to gap. These results illustrate how spatial structures in both seed bank, adult population and gap formation interact to shape plant population dynamics, as well as the occurrence of microsite- vs. seed-limitation. [source] The Nocturnal Ovipositing Behavior of Carrion Flies in Cincinnati, OhioJOURNAL OF FORENSIC SCIENCES, Issue 6 2009Trevor Stamper Ph.D. Abstract:, The behavioral patterns of nocturnal oviposition represent a window of time that potentially has a large impact on postmortem interval estimations. We investigated the behavioral patterns of carrion flies at night by exposing euthanized rats between sunset and sunrise to see if carrion flies oviposited upon the carrion over two consecutive summers. We investigated urban and rural locations, in both lit and unlit conditions with n = 125. We found that nocturnal ovipositing did not occur in the Cincinnati metropolitan area. We conclude that nocturnal oviposition is an unlikely event in the Cincinnati metropolitan area. [source] Application of direct fluid flow oscillations to improve mixing in microbioreactorsAICHE JOURNAL, Issue 10 2009X. Li Abstract This article describes an active mixing method for a microbioreactor that was designed, simulated, tested, and successfully implemented. By applying a varying pressure to a microchannel looping tangentially into a cylindrical microreactor an oscillating fluid flow was shown to occur. Such an oscillating fluid flow improved mixing, both by diffusion and convection. The oscillating fluid flow has a large impact on the ratio between the diffusion domain and the convection domain. A good match was obtained between experimental mixing results, computational fluid dynamics simulation results and the results of a simplified mixing model thus demonstrating the potential of simulation on improving the design of microreactors. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] The Role of Interbank Markets in Monetary Policy: A Model with RationingJOURNAL OF MONEY, CREDIT AND BANKING, Issue 6 2008XAVIER FREIXAS banking; rationing; monetary policy This paper analyzes the impact of asymmetric information in the interbank market and establishes its crucial role in the microfoundations of the monetary policy transmission mechanism. We show that interbank market imperfections induce an equilibrium with rationing in the credit market. This has two major implications: first, it reconciles the irresponsiveness of business investment to the user cost of capital with the large impact of monetary policy (magnitude effect), and second, it shows that banks' liquidity positions condition their reaction to monetary policy (Kashyap and Stein liquidity effect). [source] Effect of hydrodynamic multiplicity on trickle bed reactor performanceAICHE JOURNAL, Issue 1 2008Werner van der Merwe Abstract Multiple hydrodynamic states in trickle bed reactors have been the subject of numerous hydrodynamic investigations. The extent of variation in the hydrodynamic parameters (like holdup and pressure drop) is large and this variation can be expected to have a significant impact on the conversion in a reaction system. This study presents reaction data for ,-methyl styrene hydrogenation in a trickle bed reactor over a range of conditions that include gas and liquid limitations. It is seen that liquid flow rate variation induced hysteresis has a large impact on the conversion. For gas-limited reactions, the upper branch of the pressure drop hysteresis loop has a higher conversion than the lower branch at the same linear fluid velocities and catalyst weight, while for liquid-limited reactions the lower branch has a higher conversion than the upper branch (the difference in productivity being up to 20%). These trends cannot be explained by differences in wetting efficiency. Instead, it is proposed that for this system the gas,liquid mass transfer rate is the limiting step in gas-limited reactions, while the liquid,solid mass transfer rate is the limiting step in liquid-limited reactions. © 2007 American Institute of Chemical Engineers AIChE J, 2008 [source] Textural profiling and statistical optimization of crosslinked calcium-alginate-pectinate-cellulose acetophthalate gelisphere matricesJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 12 2002Viness Pillay Abstract A 25 factorial design was employed to statistically evaluate the textural properties of a crosslinked calcium-alginate-pectinate-cellulose acetophthalate gelisphere system. In accordance with the factorial matrix, gelispheres were formulated by titrating a combination polymeric solution comprised of sodium alginate, pectin and/or cellulose acetophthalate into an inducer solution (crosslinking agent) consisting of calcium and/or acetate ions. A Texture Analyzer was used to profile the gelisphere matrices for their resilience in the unhydrated and hydrated states, the fracture energy involved in matrix rupture, and the matrix hardness achieved with different levels of crosslinking. Significantly different textural properties were found among the crosslinked formulations. In particular, the unhydrated matrix resilience was selected as a parameter for optimization of the gelisphere formulation because of its large impact on drug release modulation, matrix integrity, and sensitivity to the crosslinking process. Resilience increased with increasing polymer concentration, irrespective of the polymer combination. Furthermore, resilience was not significantly influenced by the concentration of the crosslinking agents, but rather by the application of a higher polymer concentration in the crosslinking reaction; again irrespective of the polymer combination. In addition to the use of a factorial design, artificial neural modeling was employed to predict the textural properties based on the factorial matrix as a statistically suitable data source. Neural networks appeared to be a strong competitor of factorial regression for the prediction of textural data. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:2559,2570, 2002 [source] Influence of a Drinking Quantity and Frequency Measure on the Prevalence and Demographic Correlates of DSM-IV Alcohol DependenceALCOHOLISM, Issue 5 2009Katherine M. Keyes Background:, Recent research suggests that adding a quantity/frequency alcohol consumption measure to diagnoses of alcohol use disorders may improve construct validity of the diagnoses for Diagnostic and Statistical Manual of Mental and Behavior Disorders (DSM-V). This study explores the epidemiological impact of including weekly at-risk drinking (WAD) in the DMS-IV diagnostic definition of alcohol dependence via 3 hypothetical reformulations of the current criteria. Methods:, The sample was the National Epidemiologic Survey on Alcohol and Related Conditions, a nationally representative sample with 43,093 adults aged >18 in the U.S interviewed with the Alcohol Use Disorder and Associated Disabilities Interview Schedule IV. The current (DSM-IV) definition of alcohol dependence was compared with 4 hypothetical alcohol dependence reformulations that included WAD: (1) WAD added as an eighth criteria; (2) WAD required for a diagnosis; (3) adding abuse and dependence criteria together, and including WAD with a 3 of 12 symptom threshold; (4) adding abuse and dependence criteria together, and including WAD with a 5 of 12 symptom threshold. Results:, The inclusion of at-risk drinking as an eighth criterion of alcohol dependence has a minimal impact on the sociodemographic correlates of alcohol dependence but substantially increases the prevalence of dependence (from 3.8% to 5.0%). At-risk drinking as a required criterion or as part of a diagnosis that combines abuse with dependence criteria with a higher threshold (5+ criteria) decreases prevalence and has a larger impact on sociodemographic correlates. Blacks, Hispanics, and women are less likely to be included in diagnostic reformulations that include WAD, whereas individuals with low-income and education are more likely to remain diagnosed. Conclusions:, Including WAD as either a requirement of diagnosis or as an additional criterion would have a large impact on the prevalence of alcohol dependence in the general population. The inclusion of a quantity/frequency requirement may eliminate false positives from studies of alcohol disorder etiology and improve phenotype definition for genetic association studies by reducing heterogeneity in the diagnosis, but may also reduce eligibility for treatment services among women and racial/ethnic minorities compared. [source] Assessing Effectiveness of National Flood Policy Through Spatiotemporal Monitoring of Socioeconomic Exposure,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 1 2009Lauren A. Patterson Abstract:, After a century of evolving flood policies, there has been a steady increase in flood losses, which has partly been driven by development in flood prone areas. National flood policy was revised in 1994 to focus on limiting and reducing the amount of development inside the 100-year floodplain, with the goal of decreasing flood losses, which can be measured and quantified in terms of population and property value inside the 100-year floodplain. Monitoring changes in these measurable indicators can inform where and how effective national floodplain management strategies have been. National flood policies are restricted to the spatial extent of the 100-year floodplain, thus there are no development regulations to protect against flooding adjacent to this boundary. No consistent monitoring has been undertaken to examine the effect of flood policy on development immediately outside the 100-year floodplain. We developed a standardized methodology, which leveraged national data to quantify changes in population and building tax value (exposure). We applied this approach to counties in North Carolina to assess (1) temporal changes, before and after the 1994 policy and (2) spatial changes, inside and adjacent to the 100-year floodplain. Temporal results indicate the Piedmont and Mountain Region had limited success at reducing exposure within the 100-year floodplain, while the Coastal Plain successfully reduced exposure. Spatially, there was a significant increase in exposure immediately outside the 100-year floodplain throughout North Carolina. The lack of consistent monitoring has resulted in the continuation of this unintended consequence, which could be a significant driver of increased flood losses as any flood even slightly higher than the 100-year floodplain will have a disproportionately large impact since development is outside the legal boundary of national flood policy. [source] Processing of tomato: impact on in vitro bioaccessibility of lycopene and textural propertiesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2010Cecilia A Svelander Abstract BACKGROUND: Human studies have demonstrated that processing of tomato can greatly increase lycopene bioavailability. However, the difference between processing methods is not widely investigated. In the current study different thermal treatments of tomato were evaluated with regard to their impact on in vitro bioaccessibility and retention of lycopene and ,-carotene as well as textural properties. Thermal treatments used were low (60 °C) and high (90 °C) temperature blanching followed by boiling. RESULTS: Lycopene was relatively stable during thermal treatment, whereas ,-carotene was significantly (P < 0.05) reduced by all heat treatments except for low temperature blanching. In vitro bioaccessibility of lycopene was significantly increased from 5.1 ± 0.2 to 9.2 ± 1.8 and 9.7 ± 0.6 mg kg,1 for low and high temperature blanching, respectively. An additional boiling step after blanching did not further improve lycopene bioaccessibility for any treatment, but significantly reduced the consistency of low temperature treated samples. CONCLUSION: Choice and order of processing treatments can have a large impact on both lycopene bioavailability and texture of tomato products. Further investigations are needed, but this study provides one of the first steps towards tomato products tailored to optimise nutritional benefits. Copyright © 2010 Society of Chemical Industry [source] Optimization of extraction process for phenolic acids from black cohosh (Cimicifuga racemosa) by pressurized liquid extraction,JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2006Sudarsan Mukhopadhyay Abstract An investigation to optimize the extraction of phenolic acids from black cohosh using a pressurized liquid extractor system was studied with the aim of developing a generalized approach for sample preparation of phenolic compounds from plant matrices. Operating parameters such as solvent composition, solid-to-solvent ratio, temperature, particle size distribution, and number of extraction cycles were identified as main variables that influence extraction efficiency. A mixture of methanol and water (60:40 v/v) was found to be the best solvent for total phenolics (TP) and individual phenolic acids. The four phenolic acids extracted from black cohosh were identified by HPLC and LC-MS as caffeic acid, ferulic acid, sinapic acid and isoferulic acid. Over 96% of the measured phenolics were extracted in first two cycles. The extraction efficiency for black cohosh with MeOH:H2O (60:40 v/v) was found to be maximum at a solid-to-solvent ratio of 80 mg ml,1. TP content of the extract was found to increase with temperature up to 90 °C. Particle size was found to have a large impact on extraction efficiency of TP. Samples with particle size between 0.25 mm and 0.425 mm provided optimum extraction of phenolics from black cohosh. Published in 2005 for SCI by John Wiley & Sons, Ltd. [source] Chloroplast diversity in Vouacapoua americana (Caesalpiniaceae), a neotropical forest treeMOLECULAR ECOLOGY, Issue 9 2000C. Dutech Abstract The chloroplast genome has been widely used to describe genetic diversity in plant species. Its maternal inheritance in numerous angiosperm species and low mutation rate are suitable characters when inferring historical events such as possible recolonization routes. Here we have studied chloroplast DNA variation using PCR,RFLP (polymerase chain reaction,restriction fragment length polymorphism) with seven pairs of primers and four restriction enzymes in 14 populations of Vouacapoua americana (Caesalpiniaceae) a neotropical tree sampled throughout French Guiana. Population diversity (Hs), total gene diversity (Ht) and differentiation among populations (GST) were estimated using Nei's method as 0.09, 0.87 and 0.89, respectively. This is consistent with the limited gene flow associated with synzoochory in this species. The genetic structure observed in the north of French Guiana suggests that historical events such as contractions and recent recolonizations have had a large impact on the distribution of genetic diversity in this species. [source] Reproductive parameters vary with social and ecological factors in the polygynous ant Formica exsectaOIKOS, Issue 4 2008Rolf Kümmerli Due to their haplo-diploid sex determination system and the resulting conflict over optimal sex allocation between queens and workers, social Hymenoptera have become important model species to study variation in sex allocation. While many studies indeed reported sex allocation to be affected by social factors such as colony kin structure or queen number, others, however, found that sex allocation was impacted by ecological factors such as food availability. In this paper, we present one of the rare studies that simultaneously investigated the effects of social and ecological factors on social insect nest reproductive parameters (sex and reproductive allocation, nest productivity) across several years. We found that the sex ratio was extremely male biased in a polygynous (multiple queens per nest) population of the ant Formica exsecta. Nest-level sex allocation followed the pattern predicted by the queen-replenishment hypothesis, which holds that gynes (new queens) should only be produced and recruited in nests with low queen number (i.e. reduced local resource competition) to ensure nest survival. Accordingly, queen number (social factor) was the main determinant on whether a nest produced gynes or males. However, ecological factors had a large impact on nest productivity and therefore on a nest's resource pool, which determines the degree of local resource competition among co-breeding queens and at what threshold in queen number nests should switch from male to gyne production. Additionally, our genetic data revealed that gynes are recruited back to their parental nests after mating. However, our genetic data are also consistent with some adult queens dispersing on foot from nests where they were produced to nests that never produced queens. As worker production is reduced in gyne-producing nests, queen migration might be offset by workers moving in the other direction, leading to a nest network characterized by reproductive division of labour. Altogether our study shows that both, social and ecological factors can influence long-term nest reproductive strategies in insect societies. [source] Reproduction now or later: optimal host-handling strategies in the whitefly parasitoid Encarsia formosaOIKOS, Issue 1 2004Joep M. S. Burger We developed a dynamic state variable model for studying optimal host-handling strategies in the whitefly parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae). We assumed that (a) the function of host feeding is to gain nutrients that can be matured into eggs, (b) oögenesis is continuous and egg load dependent, (c) parasitoid survival is exponentially distributed and (d) parasitoids encounter hosts randomly, are autogenous and have unlimited access to non-host food sources to obtain energy for maintenance and activity. The most important prediction of the model is that host feeding is maladaptive under field conditions of low host density (0.015 cm,2) and short parasitoid life expectancy (maximum reproductive period of 7 d). Nutrients from the immature stage that can be matured into eggs are sufficient to prevent egg limitation. Both host density and parasitoid life expectancy have a positive effect on the optimal host-feeding ratio. Parasitoids that make random decisions gain on average only 35% (0.015 hosts cm,2) to 60% (1.5 hosts cm,2) of the lifetime reproductive success of parasitoids that make optimal decisions, independent of their life expectancy. Parameters that have a large impact on lifetime reproductive success and therefore drive natural selection are parasitoid life expectancy and the survival probability of deposited eggs (independent of host density), the number of host encounters per day (when host density is low) and the egg maturation rate and number of host types (when host density is high). Explaining the evolution of host-feeding behaviour under field conditions requires field data showing that life expectancy in the field is not as short as we assumed, or may require incorporation of variation in host density. Incorporating variation in walking speed, parasitised host types or egg resorption is not expected to provide an explanation for the evolution of host-feeding behaviour under field conditions. [source] Evaluation of a Non-Targeted "Omic" Approach in the Safety Assessment of Genetically Modified PlantsPLANT BIOLOGY, Issue 5 2006S. B. Metzdorff Abstract: Genetically modified plants must be approved before release in the European Union, and the approval is generally based upon a comparison of various characteristics between the transgenic plant and a conventional counterpart. As a case study, focusing on safety assessment of genetically modified plants, we here report the development and characterisation of six independently transformed Arabidopsis thaliana lines modified in the flavonoid biosynthesis. Analyses of integration events and comparative analysis for characterisation of the intended effects were performed by PCR, quantitative Real-time PCR, and High Performance Liquid Chromatography. Analysis by cDNA microarray was used as a non-targeted approach for the identification of potential unintended effects caused by the transformation. The results revealed that, although the transgenic lines possessed different types of integration events, no unintended effects were identified. However, we found that the majority of genes showing differential expression were identified as stress-related genes and that environmental conditions had a large impact on the expression of several genes, proteins, and metabolites. We suggest that the microarray approach has the potential to become a useful tool for screening of unintended effects, but state that it is crucial to have substantial information on the natural variation in traditional crops in order to be able to interpret "omics" data correctly within the framework of food safety assessment strategies of novel plant varieties, including genetically modified plant varieties. [source] Flame retarding effects of nanoclay on wood,fiber compositesPOLYMER ENGINEERING & SCIENCE, Issue 3 2007G. Guo This research article focuses on investigating the effects of nanoclay particles on the flame retarding characteristics of wood,fiber/plastic composites (WPC) using ASTM D635. The processing aspects of nanocomposites with WPC are presented. The processing techniques for controlling the degree of exfoliation and the cost aspect are also described. It turns out that the coupling agent used for wood,fibers is also effective for the exfoliation of clay, and therefore, no additional cost is required. This research indicates that the structure of nanocomposites (i.e., the degree of exfoliation) and the clay content used have a large impact on the flame retardancy of WPC. The flame retardancy is investigated as a function of these parameters. Based on this, a cost-effective way to improve flame retardancy of WPC is presented. POLYM. ENG. SCI., 47:308,313, 2007. © 2007 Society of Plastics Engineers. [source] Application of proteomics for the identification of differentially expressed protein markers for Down syndrome in maternal plasmaPRENATAL DIAGNOSIS, Issue 8 2008Aggeliki Kolialexi Abstract Background Despite the large impact of ultrasonographic and biochemical markers on prenatal screening, the ability to accurately diagnose Down syndrome (DS) is still limited and better diagnostic testing is needed. Methods Plasma from 8 women carrying a DS foetus and 12 with non-DS foetuses matched for gestational age, maternal age and ethnicity, in the second trimester of pregnancy, was analysed by two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) in order to identify biomarkers for DS. Results Gel comparison revealed nine proteins differentially expressed in maternal plasma in women with DS foetuses. Eight proteins, transthyretin (TTHY), ceruloplasmin (CERU), afamin (AFAM), alpha-1-microglobulin (AMBP), apolipoprotein E (APOE), serum amyloid P-component (SAMP), histidine-rich glycoprotein (HRG) and alpha-1-antitrypsin (A1AT) were up-regulated and one, clusterin (CLUS), down-regulated. All nine proteins are known to be involved in foetal growth and development. APOE, SAMP, AFAM and CLUS are associated with the DS phenotype. Western blot and densitometric analysis of APOE and SAMP confirmed the increase of both proteins by 19 and 48% respectively. Conclusions All differentially expressed proteins are candidate biomarkers for DS, providing opportunities for the development of non-invasive prenatal diagnosis. As these are preliminary findings, follow-up experiments are needed for their evaluation. Copyright © 2008 John Wiley & Sons, Ltd. [source] Improvement of cognitive functioning in mood disorder patients with depressive symptomatic recovery during treatment: An exploratory analysisPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 5 2006LAURA MANDELLI Psy. Abstract, Depressive symptoms have a large impact on cognitive test performance of mood disorder patients. After remission, some improvement of cognitive functioning has been observed, but also stable deficits have been reported both during depression and remission. In the present study, the authors aimed to investigate the cognitive functioning of mood disorder patients in relation to early symptomatic recovery, by comparing performances at the Wechsler Adult Intelligence Scale-Revised (WAIS-R) of responders and non-responders to the antidepressant treatment. The sample was composed of 51 hospitalized patients for a major depressive episode (major depressives/bipolars = 37/14). All patients were treated with fluvoxamine and evaluated at baseline and after 4 weeks using the 21-item Hamilton Rating Scale for Depression. All subjects were once assessed for their cognitive functioning with the WAIS-R, at the end of the fourth week of treatment. In the current sample, patients who showed a significant symptomatic remission after 4 weeks of treatment showed higher total WAIS-R scores and a lower incidence of cognitive impairment, compared to non-responders to treatment. No major differences could be observed on any particular subtest, but rather a global improving of scores in responders compared to non-responders to pharmacotherapy. Pre-treatment illness severity, that was significantly higher among non-responders, was significantly associated with patients' intelligence quotient scores. Despite a number of limitations, present data support a strong effect of depressive symptoms on patients WAIS-R performances and an early global improvement of cognitive functioning concurrent with symptomathology recovery during pharmacological treatment. [source] The regulatory and business roles of a Study DirectorQUALITY ASSURANCE JOURNAL, Issue 4 2005Celeste A. Rose Abstract The role of Study Director can be a challenging one with technical, administrative, and compliance responsibilities. The Study Director often does not have direct responsibility for personnel and other resources required for his/her studies. In this article, we have attempted to identify traits and mechanisms to help the Study Director do his/her job in a professional and compliant manner. In addition to regulatory and scientific expertise, Study Director quality attributes include possession of appropriate soft skills and character traits and are key to the success of a study. Study Directors must have an aptitude for effective communication, relationship building, training, mentoring, and delegation. While these soft skills/desirable traits often require additional effort on the part of the Study Director, they have a large impact on the rate of success, efficiency, and compliance of the study overall. The workshop presented by the authors took a 'hands-on' approach building on the creativity, and experience of Study Directors, supervisors, managers, and Quality Assurance (QA) personnel who participated. The participants deliberated problem scenarios from a Study Director's perspective. The tables and discussion in this article summarize compliant solutions, which arose from the resourcefulness that comes from experience of the participants. Copyright © 2005 John Wiley & Sons, Ltd. [source] Continuous water-level monitoring in the assessment of groundwater remediation and refinement of a conceptual site modelREMEDIATION, Issue 4 2005John J. Quinn An Erratum has been published for this article in Remediation 16(1) 2005, 155,157. Water-level data collection is a fundamental component of groundwater investigations and remediation. While the locations and depths of monitored wells are important, the frequency of data collection may have a large impact on conclusions made about site hydrogeology. Data-logging water-level probes may be programmed to record water levels at frequent intervals, providing site decision makers with abundant, detailed information on the response of an aquifer to both anticipated and unforeseen stresses. In this study, a network of movable probes has provided several years of hourly water- level data. The understanding of the site's phytoremediation system has been enhanced by the continuous data, but subsequent insights into an unexpected situation regarding the site's infrastructure have been the most valuable result of the monitoring program. © 2005 Wiley Periodicals, Inc. [source] | |||||||||||||||||||||||||||||||||||||||||||