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Threshold
Kinds of Threshold Terms modified by Threshold Selected AbstractsTEMPERATURE THRESHOLD AS A BIOGEOGRAPHIC BARRIER IN NORTHERN INDIAN OCEAN MACROALGAE,JOURNAL OF PHYCOLOGY, Issue 4 2006Tom Schils The most eastern point of the Arabian Peninsula, Ras Al Hadd, marks the boundary between the Arabian Sea and the Gulf of Oman. This geographic landmark coincides with an abrupt floristic turnover, probably one of the sharpest biotic transitions known in marine biogeography. The floras of different Arabian localities across this floristic break were compared using macrophyte distribution data throughout the Indian Ocean and seasonal sea-surface temperature (SST) data. The localities from the Arabian Gulf and Gulf of Oman differ significantly from those of the Arabian Sea based on their species richness, species composition, average distribution range per species, general temperature affinity of the composing species, and seasonal temperature data of the coastal waters. Pooling the temperature data into two groups (SST3avg, average SST of the three warmest seasons; SSTmin, minimum of the seasonal SSTs) revealed a temperature limit at 28°C using both the temperature affinity data of the floras and the seasonal temperatures recorded for the specific Arabian localities, which significantly separates the Arabian Sea from localities of both Gulfs. Finally, SST data of the Indian Ocean were analyzed using this upper temperature threshold of macrophytes at 28°C and the lower temperature limit of corals at 25°C, revealing general macrophyte diversity patterns. [source] DETERMINING A SERIES OF WHOLE WHEAT DIFFERENCE THRESHOLDS FOR USE IN A GRADUAL ADJUSTMENT INTERVENTION TO IMPROVE CHILDREN'S LIKING OF WHOLE-WHEAT BREAD ROLLSJOURNAL OF SENSORY STUDIES, Issue 6 2007JOANNE DELK ABSTRACT The first objective of this research was to determine if elementary school-aged children preferred refined bread to whole-wheat bread. The second objective was to set a series of difference threshold steps that could be used for an intervention to gradually and undetectably increase whole-wheat flour content in a bread roll. We conducted a taste test with 103 elementary school children in which they rated their liking of bread rolls containing various levels of whole wheat. The rolls with lower levels of whole wheat were liked better than the rolls with higher levels. We established difference thresholds for whole-wheat flour in rolls over the range of 0,100% whole wheat using ascending forced-choice tests. From these thresholds, we established the following series of concentrations (%): 1, 2, 5, 7, 10, 14, 21, 26, 32, 38, 47, 59, 72 and 91. PRACTICAL APPLICATIONS The series of whole wheat concentrations we determined can be used in an intervention to gradually increase the whole-wheat content of bread rolls. More broadly, they could be used by any foodservice operation, manufacturer or cook that wants to gradually increase the whole-wheat content of bread or related products and have that increase remain undetected by consumers. This strategy of gradually increasing whole-wheat content has the potential to markedly increase the consumption of whole grains, thus, improving health. [source] JOINTLY-DETERMINED ECOLOGICAL THRESHOLDS AND ECONOMIC TRADE-OFFS IN WILDLIFE DISEASE MANAGEMENTNATURAL RESOURCE MODELING, Issue 4 2007ELI P. FENICHEL ABSTRACT. We investigate wildlife disease management, in a bioeconomic framework, when the wildlife host is valuable and disease transmission is density-dependent. Disease prevalence is reduced in density-dependent models whenever the population is harvested below a host-density threshold a threshold population density below which disease prevalence declines and above which a disease becomes epidemic. In conventional models, the threshold is an exogenous function of disease parameters. We consider this case and find a steady state with positive disease prevalence to be optimal. Next, we consider a case in which disease dynamics are affected by both population controls and changes in human-environmental interactions. The host-density threshold is endogenous in this case. That is, the manager does not simply manage the population relative to the threshold, but rather manages both the population and the threshold. The optimal threshold depends on the economic and ecological trade-offs arising from the jointly-determined system. Accounting for this endogene-ity can lead to reduced disease prevalence rates and higher population levels. Additionally, we show that ecological parameters that may be unimportant in conventional models that do not account for the endogeneity of the host-density threshold are potentially important when host density threshold is recognized as endogenous. [source] INCOME THRESHOLDS AND GROWTH CONVERGENCE: A PANEL DATA APPROACH,THE MANCHESTER SCHOOL, Issue 2 2006TSUNG-WU HO This paper applies a dynamic panel model to explore whether the low-income countries ,catch up' with the rich ones by examining the threshold effects of per capita income on the convergence behavior of growth rates. Empirical evidence from 121 Penn World Table economies and 48 US states indicates that income levels have substantial impacts on the convergence behavior. First, convergence is insignificantly found in the lowest-income regimes, which is interpreted that these poor countries persist at their income levels, which cause possible income barriers-to-growth. That is, the poor countries may not be able to catch up with the rich ones easily, unless an income threshold is overcome. Second, convergence is significantly found beyond the lowest-income regime, implying that the low-income countries catch up with the rich. We conclude that when a certain income threshold is overcome, the poor countries catch up with the rich ones; hence a subsidiary income policy can be helpful. [source] Threshold-based admission control for a multimedia Grid: analysis and performance evaluationCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 14 2006Yang Zhang Abstract In a Grid-based services system facing a large number of requests with different services and profits significance, there is always a trade-off between the system profits and the Quality of Service (QoS). In such systems, admission control plays an important role: the system has to employ a proper strategy to make admission control decisions and reserve resources for the coming requests thus to achieve greater profits without violating the QoS of the requests already admitted. In this paper, we introduce three essential admission control strategies with threshold on resource reservation and a newly proposed strategy with layered threshold. Through comprehensive theoretical analyses and extensive simulations, we demonstrate that the strategy with layered threshold is more efficient and flexible than the existing strategies for Grid-based multimedia services systems. Copyright © 2006 John Wiley & Sons, Ltd. [source] Using the Steepened Plasma Profile and Wave Breaking Threshold in Laser-Plasma InteractionCONTRIBUTIONS TO PLASMA PHYSICS, Issue 8 2008P. Zobdeh Abstract In this work we evaluate the interaction of high intense laser beam with a steepened density profile. During laser interaction with underdense plasma by freely expanding plasma regime, modification of density profile is possible. In this paper we have investigated the ultra short laser pulse interaction with nonisothermal and collisionless plasma. We consider self,focusing as an effective nonlinear phenomenon that tends to increase when the laser power is more than critical rate. By leading the expanded plasma to a preferred location near to critical density, laser reflection is obtained, so the density profile will be locally steepened. The electromagnetic fields are evaluated in this new profile. We show the amplitude and period of electrical field oscillation are increased by reducing the steepened scale length. Also our numerical results identify that by reducing the steepened scale length, the electrical field is increased to wave breaking threshold limit. This high gradient electrical field causes the effective beam loading during the wave breaking phenomenon. The wave breaking can be the initial point for other acceleration regime as cavity or channel guiding regime. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] At Hospitality's Threshold: From Social Inclusion to Exilic EducationCURATOR THE MUSEUM JOURNAL, Issue 2 2009Edith Doron Museums have strived to be valued resources in an increasingly diverse society. In aspiring to broaden their audience base, their work has shifted from developing educational policies that are "object-centered" to those that are "community-centered" , a change of strategy affecting everything from programs to exhibit design. Children's museums , distinct (if not marginalized) from the serious work of the traditional art or ethnographic or natural history museum , know and indeed say in their very name , "children's museum" , that they are for the sake of someone and not about something. They have always already been attuned to the visitor at the threshold. [source] Treatment of Facial Telangiectasia With Variable-Pulse High-Fluence Pulsed-Dye Laser: Comparison of Efficacy with Fluences Immediately Above and Below the Purpura ThresholdDERMATOLOGIC SURGERY, Issue 7 2003Murad Alam MD Background. Pulsed-dye laser treatment has been shown to be highly effective for the treatment of facial telangiectasia. Posttreatment purpura after such treatment has limited patient acceptance of the procedure. Objective. To determine whether purpura-free treatment with recently introduced variable-pulsed pulsed-dye lasers can effectively reduce facial telangiectasia. Methods. This was a prospective, randomized, controlled, nonblinded trial. Eleven patients received variable-pulse pulsed-dye laser treatment with and without induction of purpura. Telangiectasia were graded on a "telangiectasia density scale," on which a 1 signified extremely fine, sparsely distributed telangiectasia, and 5 referred to thick, ropelike telangiectasia covering the affected area. For each subject, two areas on either side of the facial midline with equivalent telangiectasia density ratings were randomized to the purpura and purpura-free treatment groups, respectively. All treatments used a 7-mm spot size and a 10-ms pulse duration. The fluence associated with the purpura threshold for each patient was determined in test areas. Purpura-free treatment entailed a fluence 1.0 J/cm2 less than the purpura threshold, and purpura-level treatment entailed a fluence 0.5 J/cm2 greater than the threshold. Results. Six weeks after a single purpura-free treatment, mean telangiectasia ratings were reduced from 2.7 to 2.4. Purpura-level treatments resulted in a decrease to 1.4 from the same baseline. Thicker, denser telangiectasia appeared to benefit more from purpura-level treatment (a mean telangiectasia density scale reduction of 1.7) than finer, sparser telangiectasia (a mean reduction of 0.8). In 81% of cases, both investigators and patients rated the side treated with purpura as undergoing a greater reduction in telangiectasia density. Conclusion. Although facial telangiectasia do improve after a single purpura-free treatment with the variable-pulse pulsed-dye laser, they improve more after purpura is induced. Purpura-free and purpura-level treatments may be close to equivalent for treating fine telangiectasia, but purpura-level treatments have a distinct advantage for treating thicker telangiectasia. Significantly, the variable-pulse pulsed-dye laser offers patients the option of effective treatment of some telangiectasia without bruising. [source] Particle clusters in gravel-bed rivers: an experimental morphological approach to bed material transport and stability conceptsEARTH SURFACE PROCESSES AND LANDFORMS, Issue 11 2005Lea Wittenberg Abstract Structured gravel river beds clearly exert a major influence on bed stability. Indexing structural stability by field measurements of bed strength neglects the processes operating to entrain and transport bed material in different parts of each structure. This study takes a morphological approach to interpreting the critical processes, using particle tracing to determine the movement of individual cluster particles over a range of flood event magnitudes and durations. The experiment was carried out on the River South Tyne, UK; it uses flow hydrographs measured nearby and also benefits from previous studies of historical development, channel morphology and sediment transport at the same site. More than 30 clusters were monitored over a seven-month period during which clusters occupied 7,16 per cent of the bed. Threshold flows delimiting three apparently contrasting bed sediment process regimes for cluster particles are tentatively set at 100 m3 s,1 and 183 m3 s,1; durations of flow at these levels are critical for cluster development, rather than flow peak values. Wake particles are transported most easily. Flow straightening in the wandering channel planform reduces the stability of clusters, since mechanical strength is markedly reduced by this change of direction. The overall area covered by clusters between significant transport events varies little, implying a dynamic equilibrium condition. Copyright © 2005 John Wiley & Sons, Ltd. [source] Threshold for perception of vibration is lower at glabrous skin than at subcutaneous bone sitesEUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2006O. S. A. Oluwole No abstract is available for this article. [source] Abolishing the Tax-Free Threshold in Australia: Simulating Alternative Reforms,FISCAL STUDIES, Issue 2 2009John Creedy H24; H31 Abstract This paper examines the role of the tax-free income tax threshold in a complex tax and transfer system consisting of a range of taxes and benefits, each with its own taper rates and thresholds. Considering a tax and benefit system with benefit taper rates whereby some benefits are received by income groups other than those at the bottom of the distribution, it is suggested that a tax-free threshold is not a necessary requirement to achieve redistribution. Four alternative policy changes, each involving the elimination of the tax-free threshold in Australia and designed to achieve approximate revenue neutrality, were examined using the Melbourne Institute Tax and Transfer Simulator. A range of implications were examined, including labour supply responses to tax changes and the effects of policy changes on inequality and social welfare. The results demonstrate that it is possible to eliminate the tax-free threshold under approximate overall revenue and distribution neutrality, but that it is impossible to improve labour supply incentives at the same time. In order to achieve improved incentives, either revenue or distribution neutrality has to be sacrificed. [source] High Dielectric Permittivity and Low Percolation Threshold in Nanocomposites Based on Poly(vinylidene fluoride) and Exfoliated Graphite NanoplatesADVANCED MATERIALS, Issue 6 2009Fuan He A novel nanocomposite, based on poly-(vinylidene fluoride) and exfoliated graphite nanoplates (PVDF/xGnPs), exhibits high dielectric constant with a low percolation threshold, which can be attributed to the good dispersion of xGnP in the PVDF matrix and the formation of a large number of parallel-board microcapacitors. [source] Theoretical Implications of the Biomechanical Fracture ThresholdJOURNAL OF BONE AND MINERAL RESEARCH, Issue 10 2008Tony M Keaveny Abstract Because of the dichotomous nature of a bone fracture, when ,, the ratio of the applied impact force to the bone strength, is greater than a critical value,the biomechanical fracture threshold,fracture should occur. We sought to elucidate the conceptual implications of this biomechanical fracture threshold with application to hip fracture. We used data from the PaTH study, a 2-yr clinical trial in postmenopausal women treated with alendronate, PTH, or their combination. Outcomes included the force applied to the hip in a sideways fall as estimated from subject height and weight; femoral strength as determined by QCT-based finite element analysis; the load-to-strength ratio ,; and total hip areal BMD from DXA. Results indicated that those with "very low" femoral strength (<2000 N) invariably had load-to-strength ratio , values well above the theoretical biomechanical fracture threshold (, = 1), but those with "moderately low" femoral strength (2000,4000 N) displayed , values both above and below the theoretical biomechanical fracture threshold. This finding implies that the risk of a hip fracture can be high in those with only moderately low BMD because femoral strength can be low relative to fall impact forces. The observed weak correlation between areal BMD and the load-to-strength ratio , (r2 = 0.14) suggests that consideration of the biomechanical fracture threshold may improve fracture risk assessment, particularly for those in the osteopenic range. Regarding treatment effects, only those subjects having load-to-strength ratio , values within a relatively narrow "transition zone" of ±20% of the assumed biomechanical fracture threshold at baseline were predicted to change fracture status during the trial. In theory, outcomes of fracture trials may be dominated by the responses of those within the "transition zone" at baseline, and treatment benefits in terms of fracture efficacy may depend the patient's baseline status with respect to the biomechanical fracture threshold. We conclude that consideration of the theoretical implications of the biomechanical fracture threshold may lead to new insights and advances in the assessment and treatment of osteoporosis. [source] The Effect of Induction Method on Defibrillation Threshold and Ventricular Fibrillation Cycle LengthJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2006ENDRE ZIMA M.D. Introduction: Since no clinical data are available on the comparison of the "shock on T-wave" and "high frequency burst" ventricular fibrillation (VF) induction modes during defibrillation threshold (DFT) testing, we aimed to compare these two methods during implantable cardioverter defibrillator implantation. Methods: The DFT was determined with a step-down protocol using biphasic, anodal polarity (100%, 40%, 20% voltage control) shocks. Patients were randomized: VF was induced by 50 Hz burst in group B (n = 45) and T-wave shock in group T (n = 41). The DFT was defined as the lowest energy level that terminated VF; confirmed DFT (DFTc) was defined as the minimal energy level that consecutively terminated VF twice. Success rate of DFTc was calculated during an intraindividual test for the alternate induction method. Results: A total of 546 episodes of VF were induced: n = 278 (B) vs n = 268 (T). Incidence of VT during inductions was 9.9% (B) vs 2.7% (T), P < 0.05. Neither the DFT, 8.8 ± 4.0 J (B) vs 9.7 ± 4.2 J (T), nor the DFTc, 10.6 ± 5.1 J (B) vs 10.8 ± 4.2 J (T), proved to be significantly different. A significant correlation was found between VF cycle length (CL) and the concomitant DFT (r = 0.298, P < 0.05) in group T only. Subgroup analysis of patients under chronic class III antiarrhythmic treatment showed no increase of the DFT in either group and significantly lower incidence of VT induction in group T regardless of antiarrhythmic treatment. Conclusion: The DFT and the VFCL proved to be independent of the VF induction method. The T-wave shock was more unlikely to induce VT during DFT testing. These results suggest that both methods are reliable in DFT determination, though T-wave shock application is a more reliable method for DFT testing. [source] Reduction in Atrial Defibrillation Threshold by a Single Linear Ablation LesionJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2001JAMES B. WHITE Ph.D. Single Lesion Lowers ADFT.Introduction: This study investigated a hybrid approach to reduce the atrial defibrillation threshold (ADFT) by determining the effect of a single linear radiofrequency ablation (RFA) lesion on both the ADFT and activation patterns during atrial fibrillation (AF). Methods and Results: In 18 open chest sheep (45 to 57 kg), coil defibrillation electrodes were placed in a superior vena cava/right ventricular configuration. AF was induced by burst pacing and maintained with acetyl ,-methylcholine (2 to 42 ,L/min). ADFTs were obtained before and after a linear RFA lesion was created in the left atrium (LAL; n = 6), right atrium (RAL; n = 6), or neither atrium as a control (n = 6). In animals receiving an LAL, a 504-unipolar-electrode plaque was sutured to the LA. For animals receiving an RAL, two 504-electrode plaques were placed, one each on the LA and RA. From each plaque, activations were recorded before and after ADFT shocks, and organizational characteristics of activations were analyzed using algorithms that track individual wavefronts. In sham-treated controls, the ADFT did not change. In contrast, LAL reduced ADFT energy 29%, from 4.5 ± 2.3 J to 3.2 ± 2.0 J (P < 0.05). RAL reduced ADFT energy 25%, from 2.0 ± 0.9 J to 1.5 ± 0.7 J (P < 0.05). AF activation was substantially more organized after RFA than before RFA for both the RAL- and LAL-treated animals. Conclusion: A single RFA lesion in either the RA or LA reduces the ADFT in this sheep model. This decrease is associated with an increase in fibrillatory organization. [source] Best Estimated Aroma and Taste Detection Threshold for Guaiacol in Water and Apple JuiceJOURNAL OF FOOD SCIENCE, Issue 4 2005Thomas A. Eisele ABSTRACT: Alicyclobacillus acidoterrestris can produce sufficient guaiacol (methoxyphenol), a metabolic by-product of the bacterium, in apple juice to cause a detectable taint characterized by an antiseptic off-odor or distinct medicinal flavor and lingering aftertaste. Bacterial spoilage may not be visibly detectable. The objective of this study was to determine the best estimate threshold (BET) for detection of guaiacol in water and commercial pasteurized apple juice from concentrate using the forced-choice ascending concentration method of limits with an experienced 17-member sensory panel. The mean BET for aroma detection of guaiacol in water and apple juice was 0.48 ppb and 0.91 ppb, respectively. The mean BET for taste detection of guaiacol in water and apple juice was 0.17 ppb and 0.24 ppb, respectively. Individual aroma BET values ranged from 0.06 ppb to 4.71 ppb guaiacol in water and 0.17 ppb to 4.71 ppb for guaiacol in apple juice. Individual taste BET values ranged from 0.01 ppb to 4.71 ppb for guaiacol in water and apple juice. The taste BET was equal to or lower than the aroma BET for guaiacol in both water and apple juice for all panelists. There was about a 500-fold range in guaiacol taste detection between panelists, with some individuals exhibiting a BET value as low as 10 ppt (trillion). The information should be useful for developing quality assurance sensory methodology to evaluate potential apple juice flavor spoilage by Alicyclobacillus spp. [source] Determination of Carbonation Threshold in YogurtJOURNAL OF FOOD SCIENCE, Issue 1 2003A.O. Wright ABSTRACT: Carbonated Swiss-style yogurt ranging between 62 and 1596 ppm CO2 was evaluated for sensory detection of carbonation by 12 college-aged students. Seventy-two repetitions were completed. Each panelist received 42 3-AFC presentations. The group mean threshold was calculated as per American Society for Testing and Materials (ASTM) Method: E1432,91 (1997). Individual thresholds ranged from 181 to 390 ppm. The group mean threshold was determined to be 263 ppm. Upper and lower confidence levels (95%) for the mean were 305 and 227 ppm, respectively. This information may help industry set carbonation levels in carbonated yogurt. [source] Variety-specific Epidemiology of Cercospora beticola Sacc. and Consequences for Threshold-based Timing of Fungicide Application in Sugar BeetJOURNAL OF PHYTOPATHOLOGY, Issue 4 2010Ulrike Kaiser Abstract In Central Europe, fungicides to control leaf spot disease in sugar beet caused by Cercospora beticola are applied based on thresholds of disease incidence (DI, per cent of infected plants). As variety-specific fungicide application was not analyzed to date, the epidemiology of C. beticola and its effect on white sugar yield (WSY) in varieties with different susceptibility were investigated at seven sites in Germany and Austria in 2004 and 2005. All varieties reached the summary thresholds 5 / 15 / 45% DI in all environments. Fitting a logistic growth curve to DI revealed significant differences among varieties. At high disease pressure, susceptible varieties reached a considerably higher disease severity (DS, per cent of infected leaf area) at harvest and a larger area under disease progress curve (AUDPC) than resistant varieties. Fitting a logistic growth curve to DS showed an increasing differentiation among varieties with time. The growth rate estimated based on the logistic growth curve was the only variable that performed equally well in differentiating varieties under low and high disease pressure. With increasing disease pressure, varieties differed considerably in WSY, but differences between susceptible and resistant varieties were significant only in some environments. The disease-loss relation between AUDPC and relative WSY was variety-specific. Resistant varieties had an approximately identical WSY with and without infection and compensated for negative infection effects even at higher AUDPC. Therefore, at high disease pressure, resistant varieties had a higher relative yield compared to susceptible ones. However, our results indicate that there is no need to develop variety-specific thresholds, but resistant varieties reach the established thresholds later than susceptible ones. Consequently, the time of fungicide application can be delayed in resistant varieties. This will help to reduce the use of fungicides to the bare essentials as requested for the integrated crop protection management. [source] Commentary on White, Kraus, and Swartzwelder (2006): "Many College Freshmen Drink at Levels Far Beyond the Binge Threshold",ALCOHOLISM, Issue 6 2006Mark S. Goldman No abstract is available for this article. [source] Conductivity and Permittivity of Nickel-Nanoparticle-Containing Ceramic Materials in the Vicinity of Percolation ThresholdJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2006Umar Abdurakhmanov Conductivity and static permittivity of ceramic materials containing nanoparticles of Ni were measured in the vicinity of percolation threshold. It is found that, below this threshold, the experimentally obtained dependences of conductivity and static permittivity on the fractional Ni content in these materials are different from those calculated in the frame of the percolation theory. The origin of this discrepancy is discussed in terms of the network hierarchy model proposed recently by Balberg et al. for composite materials. [source] Glass Transition Temperature Depression at the Percolation Threshold in Carbon Nanotube,Epoxy Resin and Polypyrrole,Epoxy Resin CompositesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 5 2005Sophie Barrau Abstract Summary: The glass transition temperatures of conducting composites, obtained by blending carbon nanotubes (CNTs) or polypyrrole (PPy) particles with epoxy resin, were investigated by using both differential scanning calorimetry (DSC) and dynamical mechanical thermal analysis (DMTA). For both composites, dc and ac conductivity measurements revealed an electrical percolation threshold at which the glass transition temperature and mechanical modulus of the composites pass through a minimum. DC conductivity, ,dc, as a function of the conducting filler concentration of the CNT, (,) and PPy, (,) epoxy resin composites. [source] Development of an oligonucleotide microarray method for Salmonella serotypingMICROBIAL BIOTECHNOLOGY, Issue 6 2008B. Tankouo-Sandjong Summary Adequate identification of Salmonella enterica serovars is a prerequisite for any epidemiological investigation. This is traditionally obtained via a combination of biochemical and serological typing. However, primary strain isolation and traditional serotyping is time-consuming and faster methods would be desirable. A microarray, based on two housekeeping and two virulence marker genes (atpD, gyrB, fliC and fljB), has been developed for the detection and identification of the two species of Salmonella (S. enterica and S. bongori), the five subspecies of S. enterica (II, IIIa, IIIb, IV, VI) and 43 S. enterica ssp. enterica serovars (covering the most prevalent ones in Austria and the UK). A comprehensive set of probes (n = 240), forming 119 probe units, was developed based on the corresponding sequences of 148 Salmonella strains, successfully validated with 57 Salmonella strains and subsequently evaluated with 35 blind samples including isolated serotypes and mixtures of different serotypes. Results demonstrated a strong discriminatory ability of the microarray among Salmonella serovars. Threshold for detection was 1 colony forming unit per 25 g of food sample following overnight (14 h) enrichment. [source] Tolterodine causes measurable restoration of urethral sensation in women with urge urinary incontinence,,NEUROUROLOGY AND URODYNAMICS, Issue 4 2010Kimberly Kenton Abstract Introduction & Hypothesis Determine if treatment of urge incontinence with tolterodine results in changes in bladder and/or urethral sensation using Current Perception Threshold (CPT) testing. Methods Women with ,1 incontinence episode on 7-day diary were treated with 4 mg of long-acting tolterodine for 2-months. At baseline and 2-months, participants had CPT testing of the urethral and bladder at 3 frequencies 2000, 250, and 5 Hz. Baseline and post-treatment measures were compared using Wilcoxon Signed Rank Test. Results Seventeen women underwent baseline CPT testing. Four discontinued medication due to side effects and did not have repeated testing. Urethral CPT at 250 Hz was lower after treatment (median 1.3 [Interquartile range .69--2.1] and .75 [.45--1.2], p,=,.003) and at 5 Hz trended toward a significant decrease (1.1 [1--1.9] and .84 [.32--1.1], p,=,.06). Conclusions Urethral sensitivity improves after 2-months of tolterodine, suggesting it may restore urethral sensory nerves in addition to known motor effects. Neurourol. Urodynam. 29:555,557, 2010. © 2009 Wiley-Liss, Inc. [source] Birth on the Threshold: Childbirth and Modernity in South India by Cecilia Van HollenAMERICAN ETHNOLOGIST, Issue 3 2010MARGARET E. MACDONALD No abstract is available for this article. [source] Underestimation of Pacing Threshold as Determined by an Automatic Ventricular Threshold Testing AlgorithmPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2006WILLIAM H. SAUER In this case report, we describe markedly different pacing thresholds determined by a manual threshold test and the automatic Ventricular Capture Management algorithm. The discrepancy in pacing threshold values reported was due to the difference in the AV intervals used with the different testing methods. We propose that the differences in right ventricular dimensions with altered diastolic filling periods affected the threshold in this patient with a new passive fixation lead in the right ventricular apex. [source] The Impact of Catecholamines on Defibrillation Threshold in Patients with Implanted Cardioverter DefibrillatorsPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2005JAMES S. KALUS Objectives: To determine the effect of physiologic catecholamine concentrations on the defibrillation threshold (DFT) in patients with implanted cardioverter defibrillators. Background: DFT is the minimum energy delivered by an implanted cardioverter defibrillator that successfully converts ventricular fibrillation. DFT testing is performed under conscious sedation. Since activities of daily living enhance sympathetic tone substantially over these nadir levels, it is important to explore the impact of catecholamines on DFT. Methods: In this double-blind study, we determined DFT by the step-down method. Patients (n = 50) were stratified by beta-blocker use and then randomized to a 7-minute infusion of epinephrine, norepinephrine, or placebo. After study infusion, DFT testing was repeated. Changes in DFT with different study medications were compared. Subgroup analyses of the effects of catecholamines on DFT, based on beta-blocker use, were also performed. Results: Norepinephrine reduced DFT from baseline measurements by 22.6% (P = 0.008). Neither epinephrine nor placebo impacted DFT (P = 0.999, P = 0.317, respectively). In the subgroup analyses, DFT was reduced with norepinephrine regardless of beta-blocker use, while epinephrine reduced DFT among those receiving beta-blockers. No change in DFT was observed in either of the placebo subgroups. Conclusions: Elevation of plasma norepinephrine concentrations reduces the DFT, while elevations in epinephrine had no effect. Norepinephrine seems to reduce DFT regardless of beta-blocker therapy but epinephrine's effects are beta-blocker dependent. [source] Moricizine Induced Increase in Pacing ThresholdPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1p1 2003JOHN P. GIROD GIROD, J.P., et al.: Moricizine Induced Increase in Pacing Threshold. A 72-year-old woman who was experiencing incessant ventricular tachycardia and recurrent automatic implantable cardioverter defibrillator (AICD) firing despite amiodarone therapy was referred to the Cleveland Clinic Foundation. Myocardial ischemia and infarction were ruled out by standard means. Several antiarrhythmic medications were tried previously without success. Moricizine, 200 mg three times daily, was initiated and controlled the ventricular tachycardia. However, after the dose of moricizine was titrated upward, the patient became symptomatically bradycardic and the ECG exhibited 2:1 block of her paced rhythm and an increased ventricular pacing threshold. (PACE 2003; 26[Pt. I]:110,111) [source] Capture of Atrial Fibrillation Reduces the Atrial Defibrillation ThresholdPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 8 2002GIOVANNI Q. VILLANI VILLANI, G.Q., et al.: Capture of Atrial Fibrillation Reduces the Atrial Defibrillation Threshold. The effect of the atrial activity synchronization by single site right atrial pacing on atrial defibrillation threshold (ADFT) was investigated in patients with AF. Two series of randomized incremental cardioversion tests, with increasing energy levels from 0.5 to 10 J, were performed in 15 patients with recurrent episodes of idiopathic paroxysmal AF using two 7 Fr "single coil" catheters for internal cardioversion. After induction of sustained AF (> 10 minutes), shocks were delivered, preceded or not by 10 seconds of overdrive local atrial pacing, according to the randomization, using an external cardioverter defibrillator. A total of 187 shocks was delivered to the study population. ADFT was reduced when overdrive atrial stimulation preceded the cardioversion (3.6 ± 1.6 vs 2.9 ± 1.7 J, P = 0.02). Local atrial capture was considered on the basis of 1:1 phase locking between stimulus and atrial activation wave, and constant morphology of atrial wave criteria. Effective atrial capture was obtained in 8 of 15 patients. There was not significant difference in the mean of FF intervals of patients in which atrial capture was or was not stable (209 ± 22 vs 208 ± 28 ms). Patients were then considered according to the outcome of atrial pacing before direct current shock. A marked ADFT reduction was observed in patients with stable capture (3.8 ± 1.7 vs 2.5 ± 1.7 J, P = 0.0003), while no significant difference in ADFT was found when capture was not achieved (3.4 ± 1.6 vs 3.6 ± 1.5 J, P = NS). In conclusion, regularization of atrial electrical activity by atrial capture reduces the ADFT. A constant pacing entrainment seems to lower the energy required for electrical cardioversion by reducing the amount of fibrillating tissue. [source] Effect of Ventricular Fibrillation Duration on the Defibrillation Threshold in HumansPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2002RAINER GRADAUS GRADAUS, R., et al.: Effect of Ventricular Fibrillation Duration on the Defibrillation Threshold in Humans. Early during ventricular fibrillation, the defibrillation threshold may be low, as ventricular fibrillation most probably arises from a localized area with only a few wavefronts and the effects of global ischemia, ventricular dilatation, and sympathetic discharge have not yet fully developed. The purpose of this study was to explore the effect of the timing of shock delivery in humans. During implantation of an ICD in 26 patients (24 men, 60 ± 11 years, 19 coronary artery disease, NYHA 2.2 ± 0.4, left ventricular ejection fraction 0.42 ± 0.16), the defibrillation threshold was determined after approximately 10 and 2 seconds of ventricular fibrillation. Ventricular fibrillation was induced by T wave shocks. Mean defibrillation threshold was 9.9 ± 3.6 J after 10.3 ± 1.0 seconds. Within 2 seconds, 20 of 26 patients could be successfully defibrillated with , 8 J. In these patients, the mean defibrillation threshold was 4.0 ± 2.1 J after 1.4 ± 0.3 seconds compared to 9.5 ± 3.1 J after 10.2 ± 1.1 seconds (P < 0.001). There were no clinical differences between patients who could be successfully defibrillated within 2 seconds and those patients without successful defibrillation within 2 seconds. In the majority of patients, the defibrillation threshold was significantly lower within the first few cycles of ventricular fibrillation than after 10 seconds of ventricular fibrillation. These results should lead to exploration of earlier shock delivery in implantable devices. This could possibly reduce the incidence of syncope in patients with rapid ventricular tachyarrhythmias and ICDs. [source] Clinical Significance of the Atrial Fibrillation Threshold in Patients with Paroxysmal Atrial FibrillationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 5 2001KEIJI INOUE INOUE, K., et al.: Clinical Significance of the Atrial Fibrillation Threshold in Patients with Paroxysmal Atrial Fibrillation. AF threshold and the other electrophysiological parameters were measured to quantify atrial vulnerability in patients with paroxysmal atrial fibrillation (PAF, n = 47), and those without AF (non-PAF, n = 25). Stimulations were delivered at the right atrial appendage with a basic cycle length of 500 ms. The PAF group had a significantly larger percentage of maximum atrial fragmentation (%MAF, non-PAF: mean ± SD = 149 ± 19%, PAF: 166 ± 26%, P = 0.009), fragmented atrial activity zone (FAZ, non-PAF: median 0 ms, interquartile range 0,20 ms, PAF: 20 ms, 10,40 ms, P = 0.008). Atrial fibrillation threshold (AF threshold, non-PAF: median 11 mA, interquartile range 6,21 mA, PAF: 5 mA, 3,6 mA, P < 0.001) was smaller in the PAF group than in the non-PAF group. Sensitivity, specificity, and positive predictive value of electrophysiological parameters were as follows, respectively: %MAF (cut off at 150%, 78%, 52%, 76%), FAZ (cut off at 20 ms, 47%, 84%, 85%), AF threshold (cut off at 10 mA, 94%, 60%, 81%). There were no statistically significant differences between the non-PAF and PAF groups in the other parameters (effective refractory period, interatrial conduction time, maximum conduction delay, conduction delay zone, repetitive atrial firing zone, wavelength index), that were not specific for PAF. In conclusion, the AF threshold could be a useful indicator to evaluate atrial vulnerability in patients with AF. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||