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Modified Version (modified + version)
Selected AbstractsModified version of revised Deutsch,Märk model for electron impact K -shell ionization cross-sections of atoms at relativistic energiesINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 7 2009A. K. F. Haque Abstract A simple modification of the revised Deutsch,Märk model (RDM) [Deutsch et al., Int J Mass Spectrom 2004, 233, 13] incorporating both the ionic and relativistic corrections is proposed to investigate the K -shell ionization of 30 atomic targets with atomic numbers Z = 1,92 for incident energies up to 2 GeV. We also revisit our earlier models: modified Bell (MBELL) (Haque et al., Phys Rev A 2006, 73, 012708) and modified Kolbenstvedt (MKLV) (Uddin et al., Eur Phys J D 2006, 37, 361), for the K -shell ionization cross sections at these ultra-relativistic energies. The results from the modified version of RDM (MRDM), MBELL, and MKLV models agree well with the available experimental data and quantum mechanical calculations. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 [source] Efficiency-based h - and hp -refinement strategies for finite element methodsNUMERICAL LINEAR ALGEBRA WITH APPLICATIONS, Issue 2-3 2008H. De Sterck Abstract Two efficiency-based grid refinement strategies are investigated for adaptive finite element solution of partial differential equations. In each refinement step, the elements are ordered in terms of decreasing local error, and the optimal fraction of elements to be refined is determined based on efficiency measures that take both error reduction and work into account. The goal is to reach a pre-specified bound on the global error with minimal amount of work. Two efficiency measures are discussed, ,work times error' and ,accuracy per computational cost'. The resulting refinement strategies are first compared for a one-dimensional (1D) model problem that may have a singularity. Modified versions of the efficiency strategies are proposed for the singular case, and the resulting adaptive methods are compared with a threshold-based refinement strategy. Next, the efficiency strategies are applied to the case of hp -refinement for the 1D model problem. The use of the efficiency-based refinement strategies is then explored for problems with spatial dimension greater than one. The ,work times error' strategy is inefficient when the spatial dimension, d, is larger than the finite element order, p, but the ,accuracy per computational cost' strategy provides an efficient refinement mechanism for any combination of d and p. Copyright © 2008 John Wiley & Sons, Ltd. [source] Post-Traumatic Stress Disorder in CanadaCNS: NEUROSCIENCE AND THERAPEUTICS, Issue 3 2008Michael Van Ameringen Post-traumatic stress disorder (PTSD) has become a global health issue, with prevalence rates ranging from 1.3% to 37.4%. As there is little current data on PTSD in Canada, an epidemiological study was conducted examining PTSD and related comorbid conditions. Modified versions of the Composite International Diagnostic Interview (CIDI) PTSD module, the depression, alcohol and substance abuse sections of the Mini International Neuropsychiatric Interview (MINI), as well as portions of the Childhood Trauma Questionnaire (CTQ) were combined, and administered via telephone interview in English or French. Random digit dialing was used to obtain a nationally representative sample of 2991, aged 18 years and above from across Canada. The prevalence rate of lifetime PTSD in Canada was estimated to be 9.2%, with a rate of current (1-month) PTSD of 2.4%. Traumatic exposure to at least one event sufficient to cause PTSD was reported by 76.1% of respondents. The most common forms of trauma resulting in PTSD included unexpected death of a loved one, sexual assault, and seeing someone badly injured or killed. In respondents meeting criteria for PTSD, the symptoms were chronic in nature, and associated with significant impairment and high rates of comorbidity. PTSD is a common psychiatric disorder in Canada. The results are surprising, given the comparably low rates of violent crime, a small military and few natural disasters. Potential implications of these findings are discussed. [source] Investigating Driver Injury Severity in Traffic Accidents Using Fuzzy ARTMAPCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 6 2002Hassan T. Abdelwahab This paper applies fuzzy adaptive resonance theory MAP (fuzzy ARTMAP) neural networks to analyze and predict injury severity for drivers involved in traffic accidents. The paper presents a modified version of fuzzy ARTMAP in which the training patterns are ordered using the K,means algorithm before being presented to the neural network. The paper presents three applications of fuzzy ARTMAP for analyzing driver injury severity for drivers involved in accidents on highways, signalized intersections, and toll plazas. The analysis is based on central Florida's traffic accident database. Results showed that the ordered fuzzy ARTMAP proved to reduce the network size and improved the performance. To facilitate the application of fuzzy ARTMAP, a series of simulation experiments to extract knowledge from the models were suggested. Results of the fuzzy ARTMAP neural network showed that female drivers experience higher severity levels than male drivers. Vehicle speed at the time of an accident increases the likelihood of high injury severity. Wearing a seat belt decreases the chance of having severe injuries. Drivers in passenger cars are more likely to experience a higher injury severity level than those in vans or pickup trucks. Point of impact, area type, driving under the influence, and driver age were also among the factors that influence the severity level. [source] Reliability and validity of the Observational Gait Scale in children with spastic diplegiaDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 1 2003Anna H Mackey MS PT The aim of this study was to establish the reliability and validity of visual gait assessment in children with spastic diplegia, who were community or household ambulators, using a modified version of the Physicians Rating Scale, known as the Observational Gait Scale (OGS). Two clinicians viewed edited split-screen video recordings of 20 children/adolescents (11 males, 9 females; mean age 12 years, range 6 to 21 years) made at the time of three-dimensional gait analysis (3-DGA). Walking ability in each child was scored at initial assessment and reassessed from the same videos three months later using the first seven sections of the OGS. Validity of the OGS score was determined by comparison with 3-DGA. The OGS was found to have acceptable interrater and intrarater reliability for knee and foot position in mid-stance, initial foot contact, and heel rise with weighted kappas (wk) ranging from 0.53 to 0.91 (intrarater) and 0.43 to 0.86 (interrater). Comparison with 3-DGA suggests that these sections might also have high validity(wk range 0.38,0.94). Base of support and hind foot position had lower interrater and intrarater reliabilities (wk 0.29 to 0.71 and wk 0.30 to 0.78 respectively) and were not easily validated by 3-DGA. [source] Neural correlates of successful and partial inhibitions in children: An ERP studyDEVELOPMENTAL PSYCHOBIOLOGY, Issue 7 2009Lucy Cragg Abstract This experiment used event-related potentials (ERPs) to investigate the neural processes underlying the development of response inhibition in a modified version of the go/no-go paradigm [Cragg and Nation [2008] Developmental Science 11(6): 819,827]. N2 and P3 ERP components on correct go trials and partial and successful inhibitions were compared in 7- and 9-year-old children. A larger N2 effect on successful inhibitions was found in 9-year-olds compared to 7-year-olds at fronto-central electrodes. N2 amplitude was positively related to behavioral performance in the 7-year-olds suggesting it may reflect inhibitory processes; however, this relationship was not present in the 9-year-olds. Age differences were also apparent in the go P3, perhaps indicating differences in stimulus processing. The no-go P3 component was larger on successful than partial inhibitions. In contrast, there was no difference in N2 amplitude between partial and successful inhibitions. A significant difference was found in N2 latency however. This suggests that inhibitory processes are similar in both cases but initiated earlier on successful inhibitions. N2 latency was also shorter in 9-year-olds than 7-year-olds supporting an increase in the efficiency of response inhibition with age. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 533,543, 2009. [source] The development of change blindness: children's attentional priorities whilst viewing naturalistic scenesDEVELOPMENTAL SCIENCE, Issue 3 2009S. Fletcher-Watson Change blindness describes the surprising difficulty of detecting large changes in visual scenes when changes occur during a visual disruption. In order to study the developmental course of this phenomenon, a modified version of the flicker paradigm, based on Rensink, O'Regan & Clark (1997), was given to three groups of children aged 6,12 years and to a group of adults. This paradigm tested the ability to detect single colour, presence/absence and location changes of both high and low semantic importance in a complex scene. Semantically important changes were detected more quickly and accurately than less semantically important changes, by all age groups, indicating that children had the same attentional priorities as adults. Older children achieved more efficient and accurate detection of changes than younger children and reached almost adult level at 10,12 years old. These improvements parallel age-related developments in attention and visual perception. [source] The link between infant attention to goal-directed action and later theory of mind abilitiesDEVELOPMENTAL SCIENCE, Issue 6 2008Gisa Aschersleben Various studies have shown that infants in their first year of life are able to interpret human actions as goal-directed. It is argued that this understanding is a precondition for understanding intentional actions and attributing mental states. Moreover, some authors claim that this early action understanding is a precursor of later Theory of Mind (ToM) development. To test this, we related 6-month-olds' performance in an action interpretation task to their performance in ToM tasks at the age of 4 years. Action understanding was assessed using a modified version of the Woodward-paradigm (Woodward, 1999). At the age of 4 years, the same children were tested with the German version of the ToM scale developed by Wellman and Liu (2004). Results revealed a correlation between infants' decrement of attention to goal-directed action and their ability to solve a false belief task at the age of 4 years with no modulation by language abilities. Our results indicate a link between infant attention to goal-directed action and later theory of mind abilities. [source] Gravity bias in young and adult chimpanzees (Pan troglodytes): tests with a modified opaque-tubes taskDEVELOPMENTAL SCIENCE, Issue 3 2007Masaki Tomonaga Young human children at around 2 years of age fail to predict the correct location of an object when it is dropped from the top of an S-shape opaque tube. They search in the location just below the releasing point (Hood, 1995). This type of error, called a ,gravity bias', has recently been reported in dogs and monkeys. In the present study, we investigated whether young and adult chimpanzees also show such a gravity bias in a modified version of the original opaque-tube task. The original task by Hood and colleagues required the subject to search in a location after the object had fallen, while in the task reported here, subjects were required to predict the location before the object was dropped. Thus the present procedure does not involve explicit invisible displacement operations, one of the important components of the original procedure. In Experiment 1 both young (1.5,2.5-year-old) and adult chimpanzees predicted the location of falling food items below the releasing point even when crossed tubes were used. These gravity errors remained after the extensive experience of using the tubes themselves. Experiment 2 further tested adult and 4-year-old chimpanzees under the set-up in which the straight and crossed tubes were simultaneously presented. The results were the same as those in the previous test, suggesting that developmental changes and learning effect do not affect the gravity bias in chimpanzees. [source] Assessment of specimen adequacy reproducibility: An Italian experienceDIAGNOSTIC CYTOPATHOLOGY, Issue 4 2003Gioia Montanari M.D. Abstract Interobserver disagreement on smear adequacy may influence the evaluation of the performance of samplers as well as Pap test sensitivity and follow-up. In 1998, the Italian Group for Cervical Cancer Screening (GISCi) promoted a study on the reproducibility of adequacy criteria using a modified version of the Bethesda system. A set of 200 smears was circulated among six Italian laboratories situated in different parts of the country. For each smear, participants were requested to provide a summary judgment on its adequacy and on the cause(s) of inadequacy, if any. Agreement was measured using kappa-type statistics. The agreement among laboratories was generally good. In comparisons, among five laboratories, kappa values ranged from 0.47 to 0.66. At the consensus meeting on 42 slides, on which at least 2 laboratories dissented from the majority, agreement was reached unanimously for 31 reviewed slides and among 5,6 centers for 11. In this article, some guidance is given in order to attribute to one of the two categories satisfactory/unsatisfactory those smears that have been traditionally considered as candidates for the category of "satisfactory but limited by ," (SBLB). New Italian guidelines on adequacy proposed the GISCi are presented and the recommendation is made to eliminate the SBLB category. Diagn. Cytopathol. 2003;28:224,226. © 2003 Wiley-Liss, Inc. [source] Is the Partial Identity Account of Property Resemblance Logically Incoherent?DIALECTICA, Issue 4 2007Winner of the 2006 dialectica essay prize According to the partial identity account of resemblance, exact resemblance is complete identity and inexact resemblance is partial identity. In this paper, I examine Arda Denkel's (1998) argument that this account of resemblance is logically incoherent as it results in a vicious regress. I claim that although Denkel's argument does not succeed, a modified version of it leads to the conclusion that the partial identity account is plausible only if the constituents of every determinate property are ultimately quantitative in nature. [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] Private Investment and Political InstitutionsECONOMICS & POLITICS, Issue 1 2002David Stasavage Recent research has demonstrated a negative link between macroeconomic and political uncertainty and levels of private investment across countries. This raises the question whether certain types of government institutions might help reduce this uncertainty. North and Weingast (1989) propose that political institutions characterized by checks and balances can have beneficial effects on investment by allowing governments to credibly commit not to engage in ex post opportunism with respect to investors. In this paper I develop and test a modified version of their hypothesis, suggesting that checks and balances, on average, improve possibilities for commitment, but that they are not a necessary condition for doing so. Results of heteroskedastic regression and quantile regression estimates strongly support this proposition. [source] Depressive symptoms among mothers of children with epilepsy: A review of prevalence, associated factors, and impact on childrenEPILEPSIA, Issue 11 2009Mark A. Ferro Summary The impact of epilepsy is not limited to the child experiencing seizures, but affects all members of the family. As primary caregivers, mothers are particularly at risk for experiencing increased depressive symptoms and risk for clinical depression. The objective of this systematic review was to critically assess available evidence regarding the prevalence, associated factors, and impact of maternal depressive symptoms on child outcomes in epilepsy. Using a modified version of the Quality Index, studies were rigorously evaluated in terms of reporting, external validity, and internal validity. Limitations in the study designs and analytic techniques of previous research are discussed, and study methods to overcome these barriers are presented in order to advance this research area. Up to 50% of mothers of children with epilepsy are at risk for clinical depression. Correlates of maternal depressive symptoms include a number of modifiable risk factors such as role ambiguity, worry, and satisfaction with relationships. In addition, studies suggest that depressive symptoms in mothers have a negative impact on child outcomes in epilepsy including behavior problems and health-related quality of life. The overall mean score on the Quality Index was 9.7, indicating a midrange quality score, suggesting a need for more methodologically robust studies. [source] Seizures in the Developing Brain Cause Adverse Long-term Effects on Spatial Learning and AnxietyEPILEPSIA, Issue 12 2004Umit Sayin Summary:,Purpose: Seizures in the developing brain cause less macroscopic structural damage than do seizures in adulthood, but accumulating evidence shows that seizures early in life can be associated with persistent behavioral and cognitive impairments. We previously showed that long-term spatial memory in the eight-arm radial-arm maze was impaired in rats that experienced a single episode of kainic acid (KA)-induced status epilepticus during early development (postnatal days (P) 1,14). Here we extend those findings by using a set of behavioral paradigms that are sensitive to additional aspects of learning and behavior. Methods: On P1, P7, P14, or P24, rats underwent status epilepticus induced by intraperitoneal injections of age-specific doses of KA. In adulthood (P90,P100), the behavioral performance of these rats was compared with that of control rats that did not receive KA. A modified version of the radial-arm maze was used to assess short-term spatial memory; the Morris water maze was used to evaluate long-term spatial memory and retrieval; and the elevated plus maze was used to determine anxiety. Results: Compared with controls, rats with KA seizures at each tested age had impaired short-term spatial memory in the radial-arm maze (longer latency to criterion and more reference errors), deficient long-term spatial learning and retrieval in the water maze (longer escape latencies and memory for platform location), and a greater degree of anxiety in the elevated plus maze (greater time spent in open arms). Conclusions: These findings provide additional support for the concept that seizures early in life may be followed by life-long impairment of certain cognitive and behavioral functions. These results may have clinical implications, favoring early and aggressive control of seizures during development. [source] A case series evaluation of a modified version of interpersonal psychotherapy (IPT) for the treatment of bulimic eating disorders: A pilot studyEUROPEAN EATING DISORDERS REVIEW, Issue 4 2009Jon Arcelus Abstract Objective To determine the therapeutic outcome of a modified form of (IPT-BNm) amongst patients with Bulimia Nervosa (BN) and Eating Disorders Not Otherwise Specified (EDNOS). Method Following initial assessment, 59 patients with diagnoses of BN or EDNOS entered treatment in the form of 16 sessions of IPT-BNm. At initial assessment, patients completed measures of general psychopathology (SCL-90), Self esteem (RSE), eating psychopathology (EDE-Q), interpersonal functioning (Inventory of Interpersonal Functioning; IIP-32) and depression (BDI). At the middle and end of treatment, EDE-Q, IIP-32 and BDI measures were repeated. Results By the middle of therapy, patients had made significant improvements in terms of their eating disordered cognitions and behaviours (including reductions in EDE-Q scores, bingeing and self-induced vomiting), interpersonal functioning and levels of depression. Conclusions IPT-BNm is an effective treatment for patients with Bulimic Eating Disorders and appears to work quickly, as there were significant reductions in eating disorders symptoms within the first eight sessions of treatment. Copyright © 2009 John Wiley & Sons, Ltd and Eating Disorders Association. [source] Confabulation, but not executive dysfunction discriminate AD from frontotemporal dementiaEUROPEAN JOURNAL OF NEUROLOGY, Issue 11 2004Z. Nedjam We examined confabulation and performance on frontal/executive tasks in Alzheimer's disease (AD) patients and patients with a diagnosis of probable frontotemporal dementia (FTD). Twenty-two patients with probable AD, 10 patients with probable FTD and 32 normal control subjects entered the study. Executive functions were assessed with the Modified Card Sorting test; a verbal fluency test; the Cognitive Estimation test; and the Stroop test. Confabulations were assessed with a modified version of the Confabulation Battery. The Confabulation Battery included 10 questions tapping each of the following domains: Episodic Memory (memories of personal past episodes), Semantic Memory (knowledge of famous facts and famous people), and Personal Future (personal plans). The results revealed that both AD patients and FTD patients were clearly and equally impaired on tests of executive functions. Both patients' groups confabulated across the three tasks of the Confabulation Battery, but FTD patients confabulated significantly more than AD patients on Episodic Memory and Personal Future. The results failed to provide any evidence of a correlation between the performance on frontal/executive tasks and the tendency to produce confabulatory reports. According to our results, confabulation, more than a deficit of frontal/executive functions, discriminate between AD and FTD. Therefore, screening for confabulation and, possibly, for other types of memory distortions may constitute a useful additional clinical tool in order to discriminate AD from FTD. [source] Trait emotional intelligence: psychometric investigation with reference to established trait taxonomiesEUROPEAN JOURNAL OF PERSONALITY, Issue 6 2001K V Petrides This paper sets out the theoretical foundation of emotional intelligence (EI) as a constellation of traits and self-perceived abilities. The discriminant validity of trait EI is explored in two studies. In study 1 (N,=,227), the psychometric properties of the BarOn Emotional Quotient inventory were scrutinized through confirmatory factor analysis and the measure was found to be unifactorial. When the EQ-i was examined concurrently with the Eysenck Personality Profiler, a clear trait EI factor emerged in Eysenckian factor space. In study 2 (N,=,166), a modified version of the EQ-i was examined concurrently with the NEO PI-R and a truncated trait EI factor was isolated within the Five-Factor Model. Results are discussed with explicit reference to established personality models and it is concluded that trait EI can be conceptualized as a distinct composite construct at the primary level of hierarchical trait structures. Copyright © 2001 John Wiley & Sons, Ltd. [source] Non-equilibrium water flow characterized by means of upward infiltration experimentsEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 1 2001Summary Upward infiltration experiments under tension were used to demonstrate the presence of non-equilibrium flow in soils, the phenomenon that has important implications for the accelerated movement of fertilizers, pesticides, non-aqueous liquids, and other pollutants. Data obtained from these experiments were analysed using the single-porosity Richards equation, as well as a variably saturated, dual-porosity model and a dual-permeability model for characterizing non-equilibrium water flow. The laboratory experiments were carried out on 0.10-m-long soil cores having an internal diameter of 0.10 m. Constant pressure heads of ,0.10 and ,0.01 m were used as the lower boundary condition. Each infiltration was followed by a single-rate evaporation experiment to re-establish initial conditions, and to obtain the drying soil hydraulic properties. Pressure heads inside the cores were measured using five tensiometers, while evaporative water loss from the top was determined by weighing the soil samples. The data were analysed to estimate parameters using a technique that combined a numerical solution of the governing flow equation (as implemented in a modified version of the Hydrus-1D software) with a Marquardt,Levenberg optimization. The objective function for the parameter estimation was defined in terms of pressure head readings, the cumulative infiltration rate, and the final total water volume in the core during upward infiltration. The final total water volume was used, as well as the pressure head readings during the evaporation part. Analysis of flow responses obtained during the infiltration experiment demonstrated significant non-equilibrium flow. This behaviour could be well characterized using a model of physical non-equilibrium that divides the medium into inter- and intra-aggregate pores with first-order transfer of water between the two systems. The analysis also demonstrated the importance of hysteresis. [source] Opportunistic multiuser scheduling with reduced feedback loadEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 4 2010Yahya S. Al-HarthiArticle first published online: 27 MAY 2010 In this paper, we propose a reduced feedback opportunistic scheduling (RFOS) algorithm that reduces the feedback load while preserving the performance of opportunistic scheduling (OS). The RFOS algorithm is a modified version of our previously proposed algorithm, the DSMUDiv algorithm. The main difference is that RFOS consists of a probing process (search process) and a requesting feedback process based on a threshold. The threshold value is variable, and it depends on the probing process. To reduce the feedback rate, a quantised value indicating the modulation level is fed back, instead of the full value of the signal-to-noise ratio (SNR), which we call quantised SNR. The paper includes the closed-form expressions of the probing load, feedback load and spectral efficiency. In addition, we investigate the effect of the scheduling delay on the system throughput (STH). Under slow Rayleigh fading assumption, we compare RFOS algorithm with the DSMUDiv and optimal (full feedback load) selective diversity scheduling algorithms. Copyright © 2010 John Wiley & Sons, Ltd. [source] Changes in Chemoreflex Characteristics Following Acute Carbonic Anhydrase Inhibition in Humans a RestEXPERIMENTAL PHYSIOLOGY, Issue 6 2000Andrea Vovk The effect of carbonic anhydrase (CA) inhibition with acetazolamide (ACZ, 10 mg kg-1 I.V.) on the peripheral and central chemosensitivity and breathing pattern was investigated in four women and three men aged 25 ± 3 years using a modified version of Read's rebreathing technique. Subjects were exposed to dynamic increases in CO2 in hypoxic and hyperoxic backgrounds during control conditions and following acute CA inhibition. All manoeuvres were repeated twice and averaged for data analysis. The central chemoreflex sensitivities, estimated from the slopes of the ventilatory response to CO2 during hyperoxic rebreathing, increased following acute CA inhibition (control vs. ACZ treatment: 1.87 ± 0.66 vs. 4.07 ± 1.03 l min-1 (mmHg CO2)-1, P < 0.05). The increased slope was reflected by an increase in the rate of rise of tidal volume and breathing frequency. Furthermore with ACZ, there was a left-ward shift of the ventilation vs. end-tidal PCO2 curve during hyperoxic hypercapnia but not hypoxic hypercapnia. The peripheral chemoreflex sensitivity was isolated by subtracting the hyperoxic slope (central only) from the hypoxic slope (central and peripheral). Following ACZ administration, the peripheral chemosensitivity was blunted (control vs. ACZ treatment: 3.66 ± 0.92 vs. 1.33 ± 0.46 l min-1 (mmHg CO2)-1, P < 0.05). In conclusion, acute CA inhibition enhanced the central chemosensitivity to CO2 but diminished the peripheral chemosensitivity. [source] Student Motivation to Learn English as a Foreign LanguageFOREIGN LANGUAGE ANNALS, Issue 6 2000Kassim A. Shaaban Data were gathered through administering a modified version of the motivation scale developed by Wen (1997). The findings revealed that integrative motivation, effort, valence, expectancy, and self-estimation of ability were internally related determinants of motivation for learning EFL. Instrumental motivation was found to be related to integrative motivation and valence only. The findings also revealed that female students were more motivated than their male counterparts. Similarly, level II proficiency students were more motivated than were level III students. However, the findings did not show a significant effect on motivation related to either students' first foreign language or university major. [source] Modelling the impact of benthic filter-feeders on the composition and biomass of river planktonFRESHWATER BIOLOGY, Issue 3 2003J.-P. Descy SUMMARY 1. The POTAMON model [Everbecq E. et al. (2001) Water Research, 35, 901] has been used to simulate the effect of benthic bivalves (mainly Dreissena polymorpha) on the phytoplankton and zooplankton in a lowland Western European river (the Moselle). Here we use a modified version of the POTAMON model with five categories of phytoplankton (Stephanodiscus, Cyclotella -like, large diatoms, Skeletonema and non-siliceous algae) to model filter-feeding effects of benthic bivalves in the Moselle. Zooplankton has been represented in the model by two categories, Brachionus -like and Keratella -like rotifers. 2. According to density estimates from field surveys (Bachmann V. et al. (1995) Hydroécologie Appliquée, 7, 185, Bachmann V. & Usseglio-Polatera P. (1999) Hydrobiologia, 410, 39), zebra mussel density varied among river stretches, and increased through the year to a maximum in summer. Dreissena filtration rates from the literature were used, and mussels have been assumed to feed on different phytoplankton categories (but less on large and filamentous diatoms) as well as on rotifers. 3. The simulations suggest a significant impact of benthic filter-feeders on potamoplankton and water quality in those stretches where the mussels are abundant, their impact being maximal in summer. Consequently, different plankton groups were not affected to the same extent, depending on their period of development and on indirect effects, such as predation by mussels on herbivorous zooplankton. 4. A daily carbon balance for a typical summer shows the effect of benthic filter-feeders on planktonic and benthic processes: the flux of organic matter to the bottom is greatly enhanced at high mussel density; conversely, production and breakdown of organic carbon in the water column are reduced. Mussel removal would drive the carbon balance of the river toward autotrophy only in the downstream stretches. [source] Dynamical effects of the statistical structure of annual rainfall on dryland vegetationGLOBAL CHANGE BIOLOGY, Issue 5 2006CHRISTOPHER A. WILLIAMS Abstract In this study, we extend a model of daily dryland dynamics by parameterizing a modified version of a minimalistic annual model to examine how the statistical structure of annual rainfall and grazing intensity interact to influence dryland vegetation. With a Monte Carlo approach, an ensemble outcome provides a statistical description of likely dryland vegetation dynamics responding to variations in rainfall structure and grazing intensity. Results suggest that increased rainfall variability decreases the average and increases the variability of grass cover leading to more frequent degradation of the grass resource. Vegetation of drier regions is found to be more sensitive to interannual variability in rainfall. Concentrating this variability into an organized periodic mode further decreases the mean and increases the variability of grass cover. Hence, a shift toward lower, more variable, or more inter-annually correlated annual rainfall will likely lead to a general decrease in the grass resource and increased dryland vulnerability to degradation. Higher grazing intensity or lower annual rainfall both lead to more frequent and longer duration degradation of the grass condition. We note an interesting interaction in the response of grass biomass to grazing intensity and rainfall variability, where increased rainfall variability leads to longer duration degradation for low grazing, but shorter periods of degradation for high grazing. Once grass reaches a degraded condition, we find that woody vegetation strongly suppresses recovery even if successive rainfall is high. Overall, these findings suggest that the projected increase in interannual rainfall variability will likely decrease grass cover and potentially lead to more frequent, longer lasting degradation of dryland vegetation, particularly if enhanced rainfall variability is concentrated in long period (e.g. decadal) modes. [source] The impact of detection and treatment on lifetime medical costs for patients with precancerous polyps and colorectal cancerHEALTH ECONOMICS, Issue 12 2009David H. Howard Abstract Understanding the costs associated with early detection of disease is important for determining the fiscal implications of government-funded screening programs. We estimate the lifetime medical costs for patients with screen-detected versus undetected polyps and early-stage colorectal cancer. Typically, cost,effectiveness studies of screening account only for the direct costs of screening and cancer care. Our estimates include costs for unrelated conditions. We applied the Kaplan,Meier Smoothing Estimator to estimate lifetime costs for beneficiaries with screen-detected polyps and cancer. Phase-specific costs and survival probabilities were calculated from the Surveillance, Epidemiology, and End Results-Medicare database for Medicare beneficiaries aged ,65. We estimate costs from the point of detection onward; therefore, our results do not include the costs associated with screening. We used a modified version of the model to estimate what lifetime costs for these patients would have been if the polyps or cancer remained undetected, based on assumptions about the ,lead time' for polyps and early-stage cancer. For younger patients, polyp removal is cost saving. Treatment of early-stage cancer is cost increasing. Copyright © 2009 John Wiley & Sons, Ltd. [source] Confirmatory factor analysis and recommendations for improvement of the Autonomy-Preference-Index (API)HEALTH EXPECTATIONS, Issue 3 2010Daniela Simon PhD Dipl Psych Abstract Objective, Validation of the German version of the Autonomy-Preference-Index (API), a measure of patients' preferences for decision making and information seeking. Methods, Stepwise confirmatory factor analysis was conducted on a sample of patients (n = 1592) treated in primary care for depression (n = 186), surgical and internal medicine inpatients (n = 811) and patients with minor trauma treated in an emergency department (n = 595). An initial test of the model was done on calculation and validation halves of the sample. Both local and global indexes-of-fit suggested modifications to the scale. The scale was modified and re-tested in the calculation sample and confirmed in the validation sample. Subgroup analyses for age, gender and type of treatment setting were also performed. Results, The confirmatory analysis led to a modified version of the API with better local and global indexes-of-fit for samples of German-speaking patients. Two items of the sub-scale, ,preference for decision-making', and one item of the sub-scale, ,preference for information seeking', showed very low reliability scores and were deleted. Thus, several global indexes-of-fit clearly improved significantly. The modified scale was confirmed on the validation sample with acceptable to good indices of fit. Results of subgroup analyses indicated that no adaptations were necessary. Discussion and conclusions, This first confirmatory analysis for a German-speaking population showed that the API was improved by the removal of several items. There were theoretically plausible explanations for this improvement suggesting that the modifications might also be appropriate in English and other language versions. [source] The Adequacy of Household Survey Data for Evaluating the Nongroup Health Insurance MarketHEALTH SERVICES RESEARCH, Issue 4 2007Joel C. Cantor Objective. To evaluate the accuracy of household survey estimates of the size and composition of the nonelderly population covered by nongroup health insurance. Data Sources/Study Setting. Health insurance enrollment statistics reported to New Jersey insurance regulators. Household data from the following sources: the 2002 Current Population Survey (CPS)-March Demographic Supplement, the 1997 and 1999 National Surveys of America's Families (NSAF), the 2001 New Jersey Family Health Survey (NJFHS), a 2002 survey of known nongroup health insurance enrollees, a small 2004 survey testing alternative health insurance question wording. Study Design. To assess the extent of bias in estimates of the size of the nongroup health insurance market in New Jersey, enrollment trends are compared between official enrollment statistics reported by insurance carriers to state insurance regulators with estimates from three general population household surveys. Next, to evaluate possible bias in the demographic and socioeconomic composition of the New Jersey nongroup market, distributions of characteristics of the enrolled population are contrasted among general household surveys and a survey of known nongroup subscribers. Finally, based on inferences drawn from these comparisons, alternative health insurance question wording was developed and tested in a local survey to test the potential for misreporting enrollment in nongroup coverage in a low-income population. Data Collection/Extraction Methods. Data for nonelderly New Jersey residents from the 2002 CPS (n=5,028) and the 1997 and 1999 NSAF (n=6,467 and 7,272, respectively) were obtained from public sources. The 2001 NJFHS (n=5,580 nonelderly) was conducted for a sample drawn by random digit dialing and employed computer-assisted telephone interviews and trained, professional interviewers. Sampling weights are used to adjust for under-coverage of households without telephones and other factors. In addition, a modified version of the NJFHS was administered to a 2002 sample of known nongroup subscribers (n=1,398) using the same field methods. These lists were provided by four of the five largest New Jersey nongroup insurance carriers, which represented 95 percent of all nongroup enrollees in the state. Finally, a modified version of the NJFHS questionnaire was fielded using similar methods as part of a local health survey in New Brunswick, New Jersey, in 2004 (n=1,460 nonelderly). Principal Findings. General household sample surveys, including the widely used CPS, yield substantially higher estimates of nongroup enrollment compared with administrative totals and yield estimates of the characteristics of the nongroup population that vary greatly from a survey of known nongroup subscribers. A small survey testing a question about source of payment for direct-purchased coverage suggests than many public coverage enrollees report nongroup coverage. Conclusions. Nongroup health insurance has been subject to more than a decade of reform and is of continuing policy interest. Comparisons of unique data from a survey of known nongroup subscribers and administrative sources to household surveys strongly suggest that the latter overstates the number and misrepresent the composition of the nongroup population. Research on the nongroup market using available sources should be interpreted cautiously and survey methods should be reexamined. [source] Alcohol Drinking Patterns and Health Care Utilization in a Managed Care OrganizationHEALTH SERVICES RESEARCH, Issue 3 2004Gary A. Zarkin Objective. To estimate the relationship between current drinking patterns and health care utilization over the previous two years in a managed care organization (MCO) among individuals who were screened for their alcohol use. Study Design. Three primary care clinics at a large western MCO administered a short health and lifestyle questionnaire to all adult patients on their first visit to the clinic from March 1998 through December 1998. Patients who exceeded the National Institute on Alcohol Abuse and Alcoholism (NIAAA) guidelines for moderate drinking were given a more comprehensive alcohol screening using a modified version of the Alcohol Use Disorders Identification Test (AUDIT). Health care encounter data for two years preceding the screening visit were linked to the remaining individuals who responded to one or both instruments. Using both quantity,frequency and AUDIT-based drinking pattern variables, we estimated negative binomial models of the relationship between drinking patterns and days of health care use, controlling for demographic characteristics and other variables. Principal Findings. For both the quantity,frequency and AUDIT-based drinking pattern variables, current alcohol use is generally associated with less health care utilization relative to abstainers. This relationship holds even for heavier drinkers, although the differences are not always statistically significant. With some exceptions, the overall trend is that more extensive drinking patterns are associated with lower health care use. Conclusions. Based on our sample, we find little evidence that alcohol use is associated with increased health care utilization. On the contrary, we find that alcohol use is generally associated with decreased health care utilization regardless of drinking pattern. [source] Large eddy simulation of flow and scalar transport in a round jetHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 3 2004Hitoshi Suto Abstract Large eddy simulation (LES) was performed for a spatially developing round jet and its scalar transport at four steps of Reynolds number set between 1200 and 1,000,000. A simulated domain, which extends 30 times the nozzle diameter, includes initial, transitional, and established stage of jet. A modified version of convection outflow condition was proposed in order to diminish the effect of a downstream boundary. Tested were two kinds of subgrid scale (SOS) models: a Smagorinsky model (SM) and a dynamic Smagorinsky model (DSM). In the former model, parameters are kept at empirically deduced constants, while in the latter, they are calculated using different levels of space filtering. Data analysis based on the decay law of jet clearly presented the performance of SGS models. Simulated results by SM and DSM compared favorably with existing measurements of jet and its scalar transport. However, the quantitative accuracy of DSM was better than that of SM at a transitional stage of flow field. Computed parameters by DSM, coefficient for SGS stresses, CR and SGS eddy diffusivity ratio, ,SGS, were not far from empirical constants of SM. Optimization of the model coefficient was suggested in DSM so that coefficient CR was nearly equal in the established stage of jet but it was reduced in low turbulence close to the jet nozzle. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(3): 175,188, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20001 [source] A forward application of age associated gray and white matter networks,HUMAN BRAIN MAPPING, Issue 10 2008Adam M. Brickman Abstract To capture patterns of normal age-associated atrophy, we previously used a multivariate statistical approach applied to voxel based morphometry that identified age-associated gray and white matter covariance networks (Brickman et al. [2007]: Neurobiol Aging 28:284,295). The current study sought to examine the stability of these patterns by forward applying the identified networks to an independent sample of neurologically healthy younger and older adults. Forty-two younger and 35 older adults were imaged with standard high-resolution structural magnetic resonance imaging. Individual images were spatially normalized and segmented into gray and white matter. Covariance patterns that were previously identified with scaled subprofile model analyses were prospectively applied to the current sample to identify to what degree the age-associated patterns were manifested. Older individuals were also assessed with a modified version of the Mini Mental State Examination (mMMSE). Gray matter covariance pattern expression discriminated between younger and older participants with high optimal sensitivity (100%) and specificity (90.5%). While the two groups differed in the degree of white matter pattern expression (t (75) = 5.26, P < 0.001), classification based on white matter expression was relatively low (sensitivity = 80% and specificity = 61.9%). Among older adults, chronological age was significantly associated with increased gray matter pattern expression (r (32) = 0.591, P < 0.001) but not with performance on the mMMSE (r (31) = ,0.314, P = 0.085). However, gray matter pattern expression was significantly associated with performance on the mMMSE (r (31) = ,0.405, P = 0.024). The findings suggest that the previously derived age-associated covariance pattern for gray matter is reliable and may provide information that is more functionally meaningful than chronological age. Hum Brain Mapp 2008. © 2007 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||||||||||||||