Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Magnitude

  • absolute magnitude
  • comparable magnitude
  • different magnitude
  • district magnitude
  • earthquake magnitude
  • equal magnitude
  • field magnitude
  • flood magnitude
  • force magnitude
  • greater magnitude
  • high magnitude
  • increased magnitude
  • large magnitude
  • larger magnitude
  • low magnitude
  • lower magnitude
  • magnetic field magnitude
  • numerical magnitude
  • relative magnitude
  • response magnitude
  • same magnitude
  • similar magnitude
  • small magnitude
  • smaller magnitude
  • stress magnitude
  • sufficient magnitude

  • Terms modified by Magnitude

  • magnitude diagram
  • magnitude difference
  • magnitude earthquake
  • magnitude enhancement
  • magnitude faster
  • magnitude greater
  • magnitude increase
  • magnitude larger
  • magnitude lower
  • magnitude range
  • magnitude relation
  • magnitude representation
  • magnitude slower
  • magnitude smaller

  • Selected Abstracts


    EVOLUTION, Issue 6 2002
    Lukas F. Keller
    Abstract Understanding the fitness consequences of inbreeding (inbreeding depression) is of importance to evolutionary and conservation biology. There is ample evidence for inbreeding depression in captivity, and data from wild populations are accumulating. However, we still lack a good quantitative understanding of inbreeding depression and what influences its magnitude in natural populations. Specifically, the relationship between the magnitude of inbreeding depression and environmental severity is unclear. We quantified inbreeding depression in survival and reproduction in populations of cactus finches (Geospiza scandens) and medium ground finches (Geospiza fortis) living on Isla Daphne Major in the Galapagos Archipelago. Our analyses showed that inbreeding strongly reduced the recruitment probability (probability of breeding given that an adult is alive) in both species. Additionally, in G. scandens, first-year survival of an offspring withf= 0.25 was reduced by 21% and adults withf= 0.25 experienced a 45% reduction in their annual probability of survival. The magnitude of inbreeding depression in both adult and juvenile survival of this species was strongly modified by two environmental conditions, food availability and number of competitors. In juveniles, inbreeding depression was only present in years with low food availability, and in adults inbreeding depression was five times more severe in years with low food availability and large population sizes. The combination of relatively severe inbreeding depression in survival and the reduced recruitment probability led to the fact that very few inbred G. scandens ever succeeded in breeding. Other than recruitment probability, no other trait showed evidence of inbreeding depression in G. fortis, probably for two reasons: a relatively high rate of extrapair paternity (20%), which may lead to an underestimate of the apparent inbreeding depression, and low sample sizes of highly inbred G. fortis, which leads to low statistical power. Using data from juvenile survival, we estimated the number of lethal equivalents carried by G. scandens, G. fortis, and another congener, G. magnirostris. These results suggest that substantial inbreeding depression can exist in insular populations of birds, and that the magnitude of the inbreeding depression is a function of environmental conditions. [source]


    A bivariate Markov regime switching model is employed to verify whether the relationship between inflation and inflation uncertainty, or the negative effects of inflation and inflation uncertainty on output growth, vary with the level of inflation. Inflation and inflation uncertainty are positively correlated in the high-inflation regime. In contrast, in the low-inflation regime, the direct effect of inflation on output growth is insignificant, but the indirect negative effect on growth via inflation uncertainty is highly significant. The negative influence in a high-inflation regime is 2.664 times greater than that in a low-inflation regime. [source]

    Protein synthesis inhibition before or after stress exposure results in divergent endocrine and BDNF responses disassociated from behavioral responses

    Nitsan Kozlovsky Ph.D.
    Abstract This study aimed to assess the effects of anisomycin, a protein synthesis inhibitor, on behavioral responses, brain-derived neurotrophic factor (BDNF) and TrkB mRNA levels, and circulating corticosterone in rats,when administered before or after initial exposure to a predator scent stress stimulus. Magnitude of changes in prevalence of anxiety-like behaviors on the elevated plus-maze and exaggerated startle reaction as well as corticosterone levels and mRNA BDNF and TrkB were compared in rats exposed to predator stress, microinjected with anisomycin before or after stress exposure. Administration of anisomycin before or after stress exposure reduced anxiety-like behavior in the elevated plus-maze and reduced the mean startle amplitude 7 days postexposure. Although the behavioral responses were similar when anisomycin was microinjected before or after stress exposure, the levels of mRNAs for BDNF and TrkB, which play a role in modulation of synaptic plasticity and the consolidation process, showed varying responses. Depression and Anxiety 0:1,11, 2007. © 2007 Wiley-Liss, Inc. [source]

    Does the Morphology of Atrial Septal Aneurysm Influence Cerebral Arterial Embolus Occurrence?

    ECHOCARDIOGRAPHY, Issue 9 2007
    Jacek Kurzawski M.D., Ph.D.
    Background and Purpose: Atrial septal aneurysm (ASA) is a rare heart defect regarded as a source of arterial emboli. The main objective of the study was to assess the role of ASA morphology in the etiology of embolism.Methods: Eighty-eight subjects were included after transthoracic echocardiography positive for ASA. Medical history of embolic events was obtained in 13 patients (14.8%). Magnitude, location, size of aneurysm, oscillation, direction of bulging, the presence of interatrial shunt and source of any potential cardiac embolus material were assessed, and the size of the left atrium, the area of both atria, and the presence of any valve prolapse syndrome were recorded. The occurrence of atrial fibrillation or flutter and the presence of concomitant diseases and other clinical features were also estimated.Results: The occurrence of arterial emboli was not related to ASA morphology. Coexisting diseases, smoking and left atrial dimension were significantly correlated with the occurrence of arterial emboli.Conclusions: Ischemic events were not significantly correlated with the ASA presence. The present findings suggest other causes of vascular events in patients with ASA. [source]

    Magnitude and variability of process rates in fungal diversity-litter decomposition relationships

    ECOLOGY LETTERS, Issue 11 2005
    Christian K. Dang
    Abstract There is compelling evidence that losses in plant diversity can alter ecosystem functioning, particularly by reducing primary production. However, impacts of biodiversity loss on decomposition, the complementary process in the carbon cycle, are highly uncertain. By manipulating fungal decomposer diversity in stream microcosm experiments we found that rates of litter decomposition and associated fungal spore production are unaffected by changes in decomposer diversity under benign and harsher environmental conditions. This result calls for caution when generalizing outcomes of biodiversity experiments across systems. In contrast to their magnitude, the variability of process rates among communities increased when species numbers were reduced. This was most likely caused by a portfolio effect (i.e. statistical averaging), with the uneven species distribution typical of natural communities tending to weaken that effect. Curbing species extinctions to maintain ecosystem functioning thus can be important even in situations where process rates are unaffected. [source]

    Magnitude and sources of uncertainties in soil organic carbon (SOC) stock assessments at various scales

    E. Goidts
    Summary Uncertainties in soil organic carbon (SOC) stock assessments are rarely quantified even though they are critical in determining the significance of the results. Previous studies on this topic generally focused on a single variable involved in the SOC stock calculation (SOC concentration, sampling depth, bulk density and rock fragment content) or on a single scale, rather than using an integrated approach (i.e. taking into account interactions between variables). This study aims to apply such an approach to identify and quantify the uncertainties in SOC stock assessments for different scales and spatial landscape units (LSU) under agriculture. The error propagation method (, method) was used to quantify the relative contribution of each variable and interaction involved to the final SOC stock variability. Monte Carlo simulations were used to cross-check the results. Both methods converged (r2=0.78). As expected, the coefficient of variation of the SOC stock increased across scales (from 5 to 35%), and was higher for grassland than for cropland. Although the main source of uncertainty in the SOC stock varied according to the scale and the LSU considered, the variability of SOC concentration (due to errors from the laboratory and to the high SOC spatial variability) and of the rock fragment content were predominant. When assessing SOC stock at the landscape scale, one should focus on the precision of SOC analyses from the laboratory, the reduction of SOC spatial variability (using bulk samples, accurate re-sampling, high sampling density or stratified sampling), and the use of equivalent masses for SOC stock comparison. The regional SOC stock monitoring of agricultural soils in southern Belgium allows the detection of an average SOC stock change of 20% within 11 years if very high rates of SOC stock changes occur (1 t C ha,1 year,1). Amplitude et sources des incertitudes liées aux estimations des stocks de carbone organique dans le sol (COS) à différentes échelles Résumé Les erreurs associées aux estimations du stock de carbone organique dans le sol (COS) sont rarement quantifiées bien qu'elles puissent empêcher l'obtention de résultats significatifs. Les quelques études qui le font focalisent en général sur une seule variable nécessaire au calcul du stock de COS (concentration en COS, profondeur échantillonnée, densité apparente et contenu en fragments rocheux) ou sur une échelle spatiale particulière, sans utiliser d'approche intégrée (prenant en compte les interactions entre les variables). Cette étude a pour objectif d'utiliser une telle approche pour identifier et quantifier les incertitudes liées aux estimations de stock de COS à différentes échelles spatiales et pour diverses unités spatiales de paysages (USP) agricoles. La loi de propagation des erreurs (méthode ,) permet de quantifier la contribution relative de chaque variable et interaction à la variabilité finale du stock de COS. Les simulations de Monte Carlo sont utilisées pour la vérification croisée des résultats. Les deux méthodes ont convergé (r2= 0.78). Comme prévu, le coefficient de variation du stock de COS a proportionnellement augmenté avec l'échelle spatiale considérée (de 5 à 35%), et était plus élevé pour les cultures que pour les prairies. Bien que la principale source d'erreur sur le stock de COS soit fonction de l'échelle spatiale et du type d'USP considérés, la variabilité du contenu en COS (du fait des erreurs de laboratoire et de sa grande variabilité spatiale) et du contenu en fragments rocheux étaient prédominants. Lors de l'estimation des stocks de COS à l'échelle du paysage, l'attention devrait prioritairement porter sur la précision des analyses en COS du laboratoire, la réduction de la variabilité spatiale du COS (en utilisant des échantillons composites, un ré-échantillonnage précis, une densité d'échantillonnage élevée ou un échantillonnage stratifié), et sur l'utilisation de masses équivalentes pour comparer les stocks de COS. Le réseau régional de suivi des stocks de COS des sols agricoles dans le sud de la Belgique permet la détection d'un changement de stock de COS moyen de 20% en 11 ans pour un taux très élevé de changement en stock de COS (1 t C ha,1 year,1). [source]

    Magnitude of indoor NO2 from biomass fuels in rural settings of Ethiopia

    INDOOR AIR, Issue 1 2009
    A. Kumie
    First page of article [source]

    Magnitude and polarization of P53-specific T-helper immunity in connection to leukocyte infiltration of colorectal tumors

    Sjoerd H. van der Burg
    Abstract The tumor antigen p53 is mutated frequently and overexpressed in colorectal cancer. As a result, patients with this type of cancer commonly display p53-specific T-helper (Th) immunity. Examination of the cytokines produced by these Th-cells showed that a majority of the proliferative p53-specific T cell cultures produced none of the key cytokines (IFN,, TNF,, IL-4, IL-5 or IL-10), indicating that these p53-specific Th-responses are not polarized. In patients who exhibited p53-specific reactivity against multiple p53-epitopes, non-polarized responses could be found side by side with polarized Th-responses that produced INF, or other cytokines such as IL-10. Patients who exhibited p53-specific IFN,-producing Th cell-immunity before surgical excision of the tumor displayed higher numbers of tumor infiltrating intraepithelial leukocytes (p = 0.04) than patients lacking such responses, suggesting that the systemic presence of p53-specific Th-cells positively affects local tumor-immunity. Our data concerning the polarization-state of p53-specific Th immunity in colorectal cancer patients support the use of vaccine formulations that induce strong Th1-polarized p53-specific immunity to ensure proper (re-)programming of the anti-tumor response. © 2003 Wiley-Liss, Inc. [source]

    Factors Associated with Differences in the Magnitude of Abnormal Returns Around NYSE Versus Nasdaq Firms' Earnings Announcements

    Youngsoon Susan Cheon
    This study provides an explanation for the ,exchange effect' puzzle documented in prior accounting research. Grant (1980) finds that the magnitude of earnings announcement week abnormal returns is higher, on average, for firms traded over-the-counter than for NYSE firms. Atiase (1987) shows that this incremental ,exchange effect' persists even after controlling for firm size. We investigate potential explanations for this incremental exchange effect. We first show that even after controlling for differences in firm size, Nasdaq firms have less rich information environments and enjoy greater growth opportunities than NYSE firms. We then investigate whether differential predisclosure information environments and/or growth opportunities can explain the incremental exchange effect. The results indicate that although the absolute magnitude of the earnings announcement-related abnormal returns is inversely related to proxies for the amount of predisclosure information, the incremental exchange effect cannot be explained by differences in the predisclosure information environment. In contrast, after controlling for differences in growth opportunities across NYSE versus Nasdaq firms, and investors' heightened sensitivity to Nasdaq firms' growth opportunities in particular, there is no significant incremental exchange effect (whether or not we control for predisclosure information). These results suggest that the incremental exchange effect puzzle documented in prior research is more likely to reflect growth-related phenomena than differences in the predisclosure information environment. [source]

    Discussion of Factors Associated with Differences in the Magnitude of Abnormal Returns Around NYSE Versus Nasdaq Firms' Earnings Announcements

    Peter Easton
    First page of article [source]


    ABSTRACT This paper presents a set of analyses on sensory directional attributes used to rate experimentally designed pizza products. Consumers may or may not know the ,optimal' sensory level of attributes for pizza, so that the usefulness of the sensory directional varies by attribute. Furthermore, the sensory magnitude of each sensory directional attribute varies, as shown by the slope (B) relating the two attributes (Sensory Magnitude = A + B (Directional Rating)). The study incorporated sensory directionals into evaluation of products varied according to an experimental design. The optimal product emerging from the design does not necessarily exhibit a sensory directional profile where all attributes are ,on target', nor does a product whose sensory attributes are all on ,target' exhibit the highest level of liking. [source]

    Hepatitis C: Magnitude of the problem

    Jorge Rakela MD
    1End-stage liver disease associated with hepatitis C virus (HCV) infection has become the leading indication for liver transplantation in the United States. 2Patients with end-stage liver disease caused by HCV may have such associated comorbidities as chronic alcoholism, steatosis, or coinfection with human immunodeficiency virus 1 or other hepatitis viruses. These comorbidities may accelerate disease progression. 3As chronic hepatitis C progresses to cirrhosis, the risk for the development of hepatocellular carcinoma increases; this poses difficult management problems. 4As patients who underwent transplantation for end-stage liver disease caused by HCV infection are followed up long term, it has become clear that patient and graft survival are decreased compared with HCV-negative patients or those with cholestatic liver disorders. 5Risk factors associated with a worse outcome after transplantation include host, viral, donor, and posttransplantation factors. 6Major challenges to be addressed in the future include delineation of the optimal antiviral therapy and how to handle the need to perform retransplantation on patients who develop graft dysfunction as a result of HCV recurrence. [source]

    Magnitude of the voltage reflection coefficient of terminated reciprocal uniform lossy transmission lines

    D. Torrungrueng
    Abstract In this paper, lossy transmission lines with arbitrary loss are analyzed in detail. Interestingly, analytical results show that the magnitude of the voltage reflection coefficient could be greater than unity for some passive load terminations. However, it can be shown rigorously that the input power is always greater than or equal to the power at the load; i.e., it still satisfied the law of power conservation even when the magnitude of the voltage reflection coefficient is greater than unity. In addition, the Smith chart is also employed to graphically illustrate that the magnitude of the voltage reflection coefficient at some points along lossy transmission lines could be greater than unity for proper load terminations. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1516,1519, 2007; Published online in Wiley InterScience ( DOI 10.1002/mop.22490 [source]

    Levodopa responsiveness in disorders with parkinsonism: A review of the literature,

    MOVEMENT DISORDERS, Issue 15 2007
    Radu Constantinescu MD
    Abstract A literature review was conducted to investigate whether or not levodopa (LD) responsiveness (LR) is a useful criterion in the diagnosis of parkinsonian disorders. Although LR does appear to differ among the parkinsonian disorders, there is considerable confusion in the literature. While most patients with Parkinson's disease (PD) have a sustained benefit from LD, a small minority of patients with documented PD do not respond. The literature suggests that the LR rate is higher for multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD) than based on published diagnostic criteria. Magnitude and duration of response to LD and tolerability (time course, type and distribution of dyskinesias, mental effects and motor worsening) may be useful features in distinguishing PD, MSA, PSP, and CBD. Efforts should be directed toward better defining LR when used for diagnostic purposes and in scientific publications. © 2007 Movement Disorder Society [source]

    Evolving concepts of management of febrile neutropenia in children with cancer

    PEDIATRIC BLOOD & CANCER, Issue 2 2002
    Elmar Orudjev MD
    Abstract Background Recent investigations of febrile neutropenia in pediatric cancer patients have identified subsets of low-risk patients who can be managed with less antibiotic therapy than previously recommended standards. Methods and Materials PubMed and Medline were searched for prospective trials and reviews of febrile neutropenia in children. Magnitude and duration of fever and neutropenia, comorbidities, and therapeutic strategies were examined. Results Twenty-seven prospective trials and five reviews were identified. The child with cancer and low-risk febrile neutropenia is clinically well and afebrile within 24,96 hr of antibiotic therapy and has evidence of marrow recovery with a rising phagocyte count. Disqualifying comorbidities include leukemia at diagnosis or in relapse, uncontrolled cancer, age under 1 year, medical condition(s) that would otherwise require hospitalization and social or economic conditions that may potentially compromise access to care or compliance. Therapeutic strategies include parenteral or oral antibiotics in the hospital with early discharge or parenteral antibiotics in the outpatient setting followed by oral or parenteral therapy and daily reassessment. Although as many as 25% of low-risk patients require modification of therapy and/or hospitalization, life-threatening or fatal infection is exceptional. Conclusion One-third to one-half the children with febrile neutropenia are at low-risk of serious infection. In the context of clinic trials, they can be safely managed with inpatient or outpatient strategies that maintain close follow-up and reduce the burden of antibiotic therapy. Adoption of these alternative strategies as the standard of care should proceed with caution guided by written protocols. Med Pediatr Oncol 2002;39:77,85. © 2002 Wiley-Liss, Inc. [source]

    Venous thromboembolism risk among hospitalized patients: Magnitude of the risk is staggering

    Samuel Z. Goldhaber
    Quality assessment focuses on areas where measurement is easy and unequivocal. To determine whether high quality hospital medicine is being practiced, a natural target is assessment of the frequency of orders to implement preventive strategies against venous thromboembolism. Patient risk can be readily ascertained, and rigorous clinical trials have vetted effective strategies to prevent deep vein thrombosis and pulmonary embolism. Concentrating on reducing the risk of venous thromboembolism is worthwhile because more than 4 million surgical patients and almost 8 million medical patients warrant specific prophylaxis orders each year in the United States alone. For those who do not receive preventive measures, the result may not be apparent during the index hospitalization. More likely, such patients will tend to develop deep vein thrombosis or pulmonary embolism within the ensuing 90 days, either in a skilled nursing facility or at home in the community. It is now time for us to broaden our approach. What happens in the hospital (such as lapses in good hospital practice) does not necessarily stay in the hospital. Failure to prophylax against venous thromboembolism may have potentially devastating implications for months after hospital discharge. Am. J. Hematol., 2007. © 2007 Wiley-Liss, Inc. [source]

    Giant ultrasonic attenuation in ZnSe doped with Cr and its possible application in crystal characterization

    V. V. Gudkov
    Abstract Ultrasonic experiment was done at the frequency of 54,MHz on ZnSe:Cr2+ crystal with concentration of the dopand 3.8,×,1018,cm,3. Giant peak of attenuation of slow shear wave propagating along ,110, crystallographic direction was observed at low temperatures (about 13,K). The peak proved to be due to relaxation process in the Jahn,Teller system. Magnitude of the peak is proportional to the concentration of the dopand. This circumstance forms the basis for a new non-destructive method of characterization of the diluted crystals, which particularly could be useful for determining the low concentration of the Jahn,Teller ions. Estimation showed that the concentration of the dopand can be registered in ZnSe:Cr2+ crystal of the order of 1016,cm,3. Other Jahn,Teller ions prospective for such characterization are suggested. [source]

    Magnitude of nighttime transpiration does not affect plant growth or nutrition in well-watered Arabidopsis

    Mairgareth A. Christman
    Significant water loss occurs throughout the night via partially open stomata in many C3 and C4 plant species. Although apparently wasteful in terms of water use, nighttime transpiration (Enight) is hypothesized to benefit plants by enhancing nutrient supply. We tested the hypothesis that plants with greater Enight would have improved plant nutrient status and greater fitness, estimated as pre-bolting biomass, for Arabidopsis thaliana. Two very different levels of Enight were generated in plants by exposing them to high vs low nighttime leaf-to-air vapor pressure deficits (VPDleaf) in controlled environment chambers. An assessment of responses of nighttime leaf conductance (gnight) to VPDleaf indicated that Enight differed by at least 80% between the treatments. This large difference in Enight, imposed over the entire vegetative growth phase of Arabidopsis, had no effect on leaf nutrient content (N, Ca, K) or pre-bolting rosette biomass. The lack of response to differences in Enight held true for both a high and a low nitrogen (N) treatment, even though the low N treatment decreased leaf N and biomass by 40,60%. The N treatment had no effect on gnight. Thus, higher Enight did not provide a nutrient or growth benefit to Arabidopsis, even when the plants were N-limited. [source]

    Examining the Nature and Magnitude of Intradistrict Resource Disparities in Mid-Size School Districts

    While a growing research base has examined resource disparities across schools within large school districts, the literature has largely overlooked resource allocation in the mid-size school districts that a large portion of the nation's children attend. In this paper, we measure disparities in teacher resources within four New York State districts and conclude that intradistrict equity is not just a big city problem. We also explore the budgeting processes and mechanisms leading to these disparities, including fund-based budgeting, grant-based allocation rules, class size formulae, and ad-hoc mechanisms. We conclude with policy implications and recommendations for improving intradistrict resource equity. [source]

    Rhesus macaque milk: Magnitude, sources, and consequences of individual variation over lactation

    Katherine Hinde
    Abstract Lactation represents the greatest postnatal energetic expenditure for mammalian mothers, and a mother's ability to sustain the costs of lactation is influenced by her physical condition. Mothers in good condition may produce infants who weigh more, grow faster, and are more likely to survive than the infants of mothers in poor condition. These effects may be partially mediated through the quantity and quality of milk that mothers produce during lactation. However, we know relatively little about the relationships between maternal condition, milk composition, milk yield, and infant outcomes. Here, we present the first systematic investigation of the magnitude, sources, and consequences of individual variation in milk for an Old World monkey. Rhesus macaques produce dilute milk typical of the primate order, but there was substantial variation among mothers in the composition and amount of milk they produced and thus in the milk energy available to infants. Relative milk yield value (MYV), the grams of milk obtained by mammary evacuation after 3.5,4 h of maternal-infant separation, increased with maternal parity and was positively associated with infant weight. Both milk gross energy (GE) and MYV increased during lactation as infants aged. There was, however, a trade-off; those mothers with greater increases in GE had smaller increases in MYV, and their infants grew more slowly. These results from a well-fed captive population demonstrate that differences between mothers can have important implications for milk synthesis and infant outcome. Am J Phys Anthropol 2009. © 2008 Wiley-Liss, Inc. [source]

    Magnitude of trauma and personality change

    Klaus Fink
    In this paper the author postulates that, in post-traumatic personality structures caused by overwhelming traumatic experiences, pre-traumatic personality features and childhood experiences are of little or no relevance. Sixty-four survivors of Nazi concentration camps are examined, their concentration camp experiences detailed and pre-persecution histories and post-persecution psychopathology studied. The significance of a concentration camp experience is analytically discussed and evaluated. This study shows that 52 cases (81.2%) of the 64 survivors of concentration camps presented an almost identical depressive personality structure irrespective of their prepersecution life history. The 64 survivors of concentration camps are psychologically compared to 78 cases of people who, in view of the menacing circumstances, decided to emigrate and in this way were spared from becoming victims of the Nazi ,final solution'. Finally, the author discusses the value of psychoanalytical treatment. [source]

    Assessment of Physiological Amplitude, Duration, and Magnitude of ECG T-Wave Alternans

    Laura Burattini Ph.D.
    Background: An association between T-wave alternans (TWA) and malignant ventricular arrhythmias is generally recognized. Because relatively low levels of TWA have also been observed in healthy (H) subjects, the question arises as to whether these are ascribable to noise and artifacts, or can be given the relevance of a physiological phenomenon characterizing a preclinical condition. Methods: To answer this question, in the present study 20-minute not noisy, sinus ECG recordings, from 138 H-subjects and 148 coronary artery diseased (CAD) patients, were submitted to our adaptive match filter (AMF) procedure to identify and parameterize TWA in terms of duration (TWAD), amplitude (TWAA), and magnitude (TWAM, defined as the product of TWAD times TWAA). The 99.5th percentiles of mean values of TWAA, TWAD, and TWAM over 20-minute ECGs were used to define three threshold levels (THRD, THRA, and THRM), which allow discrimination of abnormal TWA levels. Results: Nonstationary TWA was found in all our H-subjects and CAD-patients. TWAD, TWAA, and TWAM levels were classified as being physiological in 99% of H-subjects and 87% of CAD-patients. A linear correlation (r =,0.52, P < 0.001) was found between TWAA and RR interval in the H-population. Conclusions: Our results support the hypothesis of the existence of physiological TWA levels, which are to be considered in the effort to improve reliability of nonphysiological TWA levels discrimination. [source]

    Magnitude of Error Introduced by Application of Heart Rate Correction Formulas to the Canine QT Interval

    Andrew King B.V.M.S.
    Background: Accurate detection of drug-induced QT interval changes is often confounded by concurrent heart rate changes. Application of heart rate correction formulas has been the traditional approach to account for heart rate,induced QT interval changes, and thereby identify the direct effect of the test article on cardiac repolarization. Despite numerous recent studies identifying the imprecision of these formulas they continue to be applied. Methods: Using a chronic atrioventricular dissociated His-paced canine model, heart rate correction methods were evaluated for their ability to generate a corrected QT interval independent of original heart rate. Additionally, His bundle pacing at a heart rate of 60 beats/min allowed calculation of the magnitude of error introduced by application of heart rate correction formulas. Results: Of the fixed parameter heart rate correction formulas, only Van de Water was able to predict corrected QT values independent of the original heart rate. The magnitude of error discovered by application of heart rate correction formulas varied, but in many cases was very large. Bazett's formula was associated with a mean overcorrection of 67.9 ms; Fridericia's 28.7 ms. Van de Water was the best fixed parameter formula with a mean error of 10.8 ms. As expected, group and individual corrections derived from linear regression of the HR-QT data offered improvement over the traditional formulas. Both were able to predict QTc values independent of the heart rate. However, errors of the magnitude of 10 and 6 ms, respectively, were still introduced. Conclusion: Van de Water and linear regression correction methods were superior to others in this study, but all methods generated QTc errors equal to or much greater than the magnitude of interest for drug safety evaluation. [source]

    Growth and survival of three small abalone Haliotis diversicolor populations and their reciprocal crosses

    Wei-Wei You
    Abstract The aquaculture industry of small abalone Haliotis diversicolor in southern China is now close to collapse because of high mortality at the grow-out stage. To examine if survival and growth (shell length increase) could be improved by cross breeding among populations, a 3 × 3 complete diallel cross was conducted among three populations from Japan (A), Taiwan (B) and Vietnam (C). Performances in growth rate and survival at early juvenile, later juvenile and grow-out stages were compared among the six reciprocal cross lines and three parental lines. Magnitude of heterosis for survival and growth varied among cross lines in the three growing stages. As to mid-parent heterosis, HAB was significantly (P<0.01) higher than HAC and HBC at all three growing stages for both growth and survival, and all mid-parent heterosis fell between the two corresponding single-parent heterosis. HAB was 6.84% for shell length and 69.09% for survival at Day 420. Our results of high survival heterosis in line AB and line BA show that crossbreeding between different populations can benefit the small abalone breeding programs and the industry. [source]

    Das Magnitude 8.8 Maule (Chile)-Erdbeben vom 27.

    BAUTECHNIK, Issue 10 2010
    Februar 2010, Ingenieuranalyse der Tsunamischäden, Teil
    Das Maule (Chile)-Erdbeben vom 27. Februar 2010 gehört zu den stärksten, weltweit jemals registrierten Erdbeben. Das seismische Ereignis löste einen Tsunami aus, der durch mehrere Wellenfronten verheerende Schäden an der Küste Chiles verursachte. Ereignisspezifische Besonderheiten aus der überlagerung der Effekte aus Erdbeben und darauffolgenden Flutwellen (Tsunami) waren Motivation, im Rahmen einer Erkundungsmission der Ingenieurgruppe der Deutschen Task Force im betroffenen Gebiet die Bauwerksschäden aufzunehmen und ihre regionale Verteilung zu dokumentieren. Der Beitrag vermittelt einen Eindruck von den durch den Tsunami bedingten Schäden; es wird der Versuch unternommen, das Verhalten der typischen Bauweisen unter den zeitlich sequentiell auftretenden extremen Einwirkungen aufzuzeigen. Die Auswertungen schließen an die Ingenieuranalyse der Erdbebenschäden an, so dass auf die im vorangegangenen 1. Teil des Beitrags vom August 2010 [1] gegebene allgemeine übersicht zum Gebäudebestand in Chile und zur Typisierung der Bauweisen verwiesen werden kann. Die Schäden aus dem Tsunami konzentrieren sich auf die eher ländlichen und ohnehin weniger tauglichen traditionellen Bauweisen in den Küstenregionen. An den wesentlichen Wirkungsmechanismen eines Tsunami werden die Verletzbarkeit der Bauweisen und die Effizienz einfacher baulicher Schutzmaßnahmen herausgearbeitet. Wie gezeigt werden kann, tragen Schäden aus Treibgut erheblich zum Schadensbild bei. The Magnitude 8.8 Maule (Chile) earthquake of February 27, 2010 , Engineering analysis of tsunami damages. The Maule (Chile) February 27, 2010 earthquake is regarded as one of the strongest earthquakes ever recorded world-wide. The seismic event triggered a tsunami which caused by several wave fronts serious damage alongside the coastal border. Event-specific characteristics from the overlay of the effects from earthquakes and following flood wave (Tsunami) were motivation to examine building damage and to document their regional distribution, in the context of a reconnaissance mission of the engineering group of the German Task Force for earthquakes. The paper provides an impression from the tsunami induced damage to the different building types under the impact of time-varying sequence of extreme natural events. First results of the studies in [1] are related to the engineering analysis of earthquake damage. Therefore it can be referred to the overview of the building stock and the predominant structural systems in Chile given there. Damage caused by the tsunami is concentrated on rural and often less resistant traditional buildings in coastal areas. The main loading and impact components induced by the tsunami are used to explain the vulnerability of building types and the efficiency of simple structural measures. As the damage cases demonstrate, debris in its general sense has contributed to the observed effects. [source]

    Das Magnitude 8.8 Maule (Chile)-Erdbeben vom 27.

    BAUTECHNIK, Issue 8 2010
    Februar 2010, Ingenieuranalyse der Erdbebenschäden
    Das Maule (Chile)-Erdbeben vom 27. Februar 2010 gehört zu den stärksten, weltweit jemals registrierten Erdbeben. Die Bruchzone erstreckt sich über eine Länge von 500 km und eine Breite von 100 km, so dass acht Millionen Einwohner Chiles von dem Erdbeben mehr oder weniger direkt von den Schütterwirkungen betroffen waren. Bilder von spektakulären Schadensfällen aus der ca. 330 km entfernten Hauptstadt prägten die internationale Berichterstattung. Das seismische Ereignis löste einen Tsunami aus, der verheerende Schäden an der Küste Chiles verursachte und auch an den Küsten Hawaiis noch deutlich wahrgenommen werden konnte. Die seismischen Bodenbewegungen wurden bis ins Nachbarland Argentinien verspürt. Die Stärke des Bebens und ereignisspezifische Besonderheiten waren Motivation, im Rahmen einer Erkundungsmission der Ingenieurgruppe der Deutschen TaskForce Erdbeben im betroffenen Gebiet die Bauwerksschäden aufzunehmen und ihre regionale Verteilung zu dokumentieren. In fünf temporär, mit Starkbeben-Sensoren instrumentierten Gebäuden konnten mehrere Nachbeben aufgezeichnet werden, deren Beschleunigungsamplituden für allgemeine Hochbauten in deutschen Erdbebengebieten von Interesse bzw. maßgeblich wären. Die vorliegenden Messdaten ermöglichen die Interpretation der realen Gebäudereaktion und können in Folgeuntersuchungen zur Kalibrierung analytischer Modelle herangezogen werden. Der Beitrag vermittelt einen Eindruck von den erdbebenbedingten Schäden und soll das Verhalten der typischen Bauweisen unter diesen extremen Einwirkungen aufzeigen, das vor Ort festgestellte geringe Schadensausmaß durch die Umsetzung von Baunormen und darin verankerten Bemessungskonzepten erklären und letztlich die Übertragbarkeit dieser Beobachtungen auf andere Erdbebenregionen hinterfragen. In einem Folgebeitrag [1] werden die Schäden aus dem Tsunami einer Ingenieuranalyse unterzogen und die wesentlichen Wirkungsmechanismen bzw. einfachen baulichen Schutzmaßnahmen herausgearbeitet. The Magnitude 8.8 Maule (Chile) Earthquake of February 27, 2010 , Engineering analysis of earthquake damage. The Maule (Chile) February 27, 2010 Earthquake is regarded as one of the strongest earthquakes ever recorded world-wide. The rupture zone reached a length of about 500 km and a width of about 100 km; almost 8 million inhabitants were directly affected by the consequences of the earthquake. Photos from spectacular failure cases in the Capital (330 km away) were documented across the world and dominated the international reporting. The seismic event triggered a tsunami which caused serious damage alongside the coastal border; the waves were observed in the far-distant Hawaii Islands, too. The seismic ground motions were felt in the neighboring country Argentina, as well. The strength of the earthquake and the event-specific characteristics motivated the "Engineering Group of the German Task Force for earthquake" to analyze the building damage and to document their regional distribution. Five multi-storey RC structures were temporarily equipped with Strong-Motion sensors. Several aftershocks could be recorded; the peak acceleration amplitudes were in a level which was of interest for buildings in highest zone of German earthquake regions. In a first attempt, the measurements are used to interpret the response of real buildings in both horizontal directions; in ongoing studies data are used for the calibration of analytical models. The paper provides an overview of the earthquake induced damages in several building types and its variation within different structural systems. Reasons of low to moderate observed damage will be discussed in close relation to the code development and the preferred design concepts. The application of observed effects and derived lessons to other seismic regions is critically reviewed. In a subsequent paper [1] the damage caused by the tsunami is investigated in more detail. The engineering analysis will include the currently used models for the impact description and will elaborate simple, but quite efficient measures of protection. [source]

    Quantifying the Magnitude of Baseline Covariate Imbalances Resulting from Selection Bias in Randomized Clinical Trials

    Vance W. Berger
    Abstract Selection bias is most common in observational studies, when patients select their own treatments or treatments are assigned based on patient characteristics, such as disease severity. This first-order selection bias, as we call it, is eliminated by randomization, but there is residual selection bias that may occur even in randomized trials which occurs when, subconsciously or otherwise, an investigator uses advance knowledge of upcoming treatment allocations as the basis for deciding whom to enroll. For example, patients more likely to respond may be preferentially enrolled when the active treatment is due to be allocated, and patients less likely to respond may be enrolled when the control group is due to be allocated. If the upcoming allocations can be observed in their entirety, then we will call the resulting selection bias second-order selection bias. Allocation concealment minimizes the ability to observe upcoming allocations, yet upcoming allocations may still be predicted (imperfectly), or even determined with certainty, if at least some of the previous allocations are known, and if restrictions (such as randomized blocks) were placed on the randomization. This mechanism, based on prediction but not observation of upcoming allocations, is the third-order selection bias that is controlled by perfectly successful masking, but without perfect masking is not controlled even by the combination of advance randomization and allocation concealment. Our purpose is to quantify the magnitude of baseline imbalance that can result from third-order selection bias when the randomized block procedure is used. The smaller the block sizes, the more accurately one can predict future treatment assignments in the same block as known previous assignments, so this magnitude will depend on the block size, as well as on the level of certainty about upcoming allocations required to bias the patient selection. We find that a binary covariate can, on average, be up to 50% unbalanced by third-order selection bias. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Steady and dynamic shear rheology of glutinous rice flour dispersions

    Byoungseung Yoo
    Summary The steady and dynamic shear rheological properties of Korean glutinous rice flour dispersions were evaluated at different concentrations (4, 5, 6, 7 and 8%). Glutinous rice flour dispersions at 25 °C showed a shear-thinning behaviour (n = 0.487,0.522) with low magnitudes of Casson yield stresses (,oc = 0.056,0.339 Pa). The magnitudes of ,oc, consistency index (K) and apparent viscosity (,a,100) increased with the increase in concentration. The power law model was found to be more suitable than the exponential model in expressing the relationship between concentration and apparent viscosity. The apparent viscosity over the temperature range of 25,70 °C obeyed the Arrhenius temperature relationship, with high determination coefficients (R2 = 0.982,0.998), indicating that the magnitudes of activation energies (Ea) were in the range of 9.05,11.89 kJ mol,1. A single equation, combining the effects of temperature and concentration on ,a,100, was used to describe the flow behaviour of glutinous rice flour dispersions. Magnitudes of storage (G,) and loss (G,,) moduli increased with the increase in concentration and frequency. Magnitudes of G, were higher than those of G,, over most of the frequency range. [source]


    B. YOO
    Rheological properties of fermented hot pepper-soybean paste (HPSP) were evaluated at different total solid contents (TS, 43.6-54.7%) and temperatures (10-40C). HPSP samples at 20C are highly shear thinning fluids (n=0.25-0.33) with large magnitudes of Casson yield stresses (106-573 Pa). Consistency index (K) and apparent viscosity (,a,20) increased with increase in TS. Apparent viscosity of HPSP obeyed the Arrhenius temperature relationship. The magnitudes of activation energy (7.6-20.4 kJ/mole) for HPSP increased with increase in TS. A single equation, combining the effects of temperature and concentration on ,a,20, was used to describe flow behavior of HPSP. The time-dependent model of Weltman was found to be most applicable (R2= 0.97-0.99) for HPSP. Storage (G') and loss (G") moduli increased with increase in TS, while complex viscosity (,*) decreased. Magnitudes of G'were higher than those of G" over the entire range of frequencies (,). [source]

    Colonization history, ecological shifts and diversification in the evolution of endemic Galápagos weevils

    MOLECULAR ECOLOGY, Issue 4 2008
    Abstract Mitochondrial DNA sequence data were obtained for eight species of flightless Galapaganus endemic weevils and one winged close relative in order to study their colonization history and modes of diversification in the Galápagos Archipelago. Contrary to most other insular radiations, the phylogeny estimates we recovered for Galapaganus do not follow the progression rule of island biogeography. The penalized likelihood age estimates of colonization of the archipelago exceed the age of the emerged islands and underscore the potential role of now sunken seamounts for the early evolution of Galapaganus. The phylogeny proposes one intra-island origin for Galapaganus endemics, but monophyly tests suggest a larger contribution of in-situ speciation on older islands. Generalist habitat preferences were reconstructed as ancestral while shifts to highland habitats were reconstructed as having evolved independently on different islands. Magnitudes and patterns of diversification rate were found to differ between older and younger islands. Our analyses reveal that the colonization sequence of islands and timing of colonization of Galapaganus could be linked with the geological and volcanic history of the islands in a rather complex scenario. Even though most islands appear to have been colonized soon after their emergence, there are notable deviations from the pattern of sequential colonization expected under the progression rule when considering only the extant emerged islands. Patterns of diversification rate variation on older and younger islands correspond to the volcanic activity or remnants of such activity, while the pattern of independent evolution of restricted habitat preferences in different islands suggests that habitat shifts could also have contributed to species diversity in Galapaganus. [source]