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Simple Test (simple + test)

Distribution by Scientific Domains

Medical Sciences	42%
Mathematics and Statistics	21%
Psychology	10%
Life Sciences	10%
Business, Economics, Finance and Accounting	10%

Selected Abstracts

A Simple Test of Friedman's Permanent Income Hypothesis

ECONOMICA, Issue 289 2006
JOSEPH P. DEJUAN
Friedman's Permanent Income Hypothesis (PIH) predicts that the income elasticity of consumption should be higher for households for which a large fraction of the variation of their income is permanent than for households facing more transitory variations in income. We test this prediction using modern household data from the US Consumer Expenditure Survey. The results offer some support for the PIH. [source]

Four Simple Tests of Campaign Contributions and Trade Policy Preferences

ECONOMICS & POLITICS, Issue 2 2004
Eugene Beaulieu
This paper uses campaign contribution data to examine trade policy preferences among political action committees. With perfect factor mobility, as the Heckscher,Ohlin (HO) model assumes, interest group trade positions should depend on their factor of production but not on their industry. We show, consistent with the 2 × 2 HO model, that capital groups consistently back representatives supporting trade liberalization while labor groups favor protectionists. Unlike previous work, we also measure the variation in trade policy preferences within capital and labor groups. We find evidence that the industry net export position significantly affects labor unions' trade policy preferences. Industry characteristics have no impact on capital group lobbying. The former result suggests that empirical analyses of labor PAC contributions that exclude industry characteristics may be misspecified. [source]

Some Simple Tests for Spatial Effects Around Putative Sources of Health Risk

BIOMETRICAL JOURNAL, Issue 4 2007
Andrew B. Lawson
Abstract The need for tests dealing with different features of small area health data is less important with the increase in computation speed of computers and the access to MCMC methods. However there are many situations where exploratory testing could be useful and where MCMC methods are not readily useable or available. In this paper, a number of simple tests are derived for the logistic model for case events. This model assumes that a control disease is available and that the events have a binary label relating to case or control state. The tests are derived from likelihood considerations and Monte Carlo critical regions are examined. A simulated evaluation of the tests is presented in terms of Monte Carlo power. A data example is considered. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Adaptive through-thickness integration for accurate springback prediction

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 5 2008
I. A. Burchitz
Abstract Accurate numerical prediction of springback in sheet metal forming is essential for the automotive industry. Numerous factors influence the accuracy of prediction of this complex phenomenon by using the finite element method. One of them is the numerical integration through the thickness of shell elements. It is known that the traditional numerical schemes are very inefficient in elastic,plastic analysis and even for simple problems they require up to 50 integration points for an accurate springback prediction. An adaptive through-thickness integration strategy can be a good alternative. The main characteristic feature of the strategy is that it defines abscissas and weights depending on the integrand's properties and, thus, can adapt itself to improve the accuracy of integration. A concept of an adaptive through-thickness integration strategy for shell elements is presented in this paper. Its potential is demonstrated using two examples. Calculations of a simple test,bending a beam under tension,show that for a similar set of material and process parameters the adaptive rule with seven integration points performs significantly better than the traditional trapezoidal rule with 50 points. Simulations of an unconstrained cylindrical bending problem demonstrate that the adaptive through-thickness integration strategy for shell elements can guarantee an accurate springback prediction at minimal costs. Copyright © 2007 John Wiley & Sons, Ltd. [source]

The use of thrombelastography to determine coagulation status in severe anorexia nervosa: A case series

INTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 4 2010
Jennifer L. Gaudiani MD
Abstract Objective: Hospitalized patients with severe anorexia nervosa (AN) frequently have a complex coagulation profile, with elements of hypocoagulability-thrombocytopenia and elevated international normalized ratio (INR) and elements of hypercoagulability-usually manifested as immobility, which is either due to their marked weakness or from enforced degrees of bed rest to minimize energy expenditure. Hospitalized medical patients have been shown to have appropriate prophylaxis for venous thromboembolic (VTE) disease in only 40% of cases. Method: A simple test that could evaluate the overall coagulation profile of these patients would help guide appropriate VTE prophylaxis. The thrombelastogram is a blood test that evaluates the full dynamic process of hemostasis. Results: The study of patients did not reveal evidence of being hypocoagulable and thus should be considered for VTE prophylaxis. Discussion: We report on three cases of young women with severe AN and weakness, hospitalized for closely monitored refeeding, in whom the thromboelastogram was used to evaluate the coagulation status of the patient and assist in guiding therapy. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010 [source]

The Fimbrio-Ovarian Relation and Its Role on Ovum Picking in Unexplained Infertility: The Fimbrio-Ovarian Accessibility Tests,

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 1 2000
Dr. Saeed Mohamad Ahmad-Thabet
Abstract Objective: To study the ovum pickup mechanism and the fimbrio-ovarian relation in fertile women and cases of unexplained infertility and to design a method for investigation and anticipation of the state of ovum pickup. Design: Prospective clinical study. Setting: Department of obstetrics and gynecology Kasr El Aini Hospital, Cairo University, Egypt. Patients: Fifty fertile and 25 cases of unexplained infertility. Interventions: In all of cases the fimbrio-ovarian relation is studied by determining the length of the free ovarian border between the ovarian ligament and the fimbria ovarica that contains the corpus luteum (the ovulation border), the site of ovulation on that border and the length of the fimbria ovarica. It is also determined by a simple test "The fimbrio-ovarian accessibility test." The fimbriae are held by non-traumatizing grasper and their ability to reach and/or to cover the ovulation site are taken as a prove for successful ovum pickup. In addition, cases having suspected failed ovum picking are treated by controlled supero-vulation, also by drilling of the ovary at an accessible site to the fimbria ovarica and by freeing short fimbria ovarica with or without its advancement on the ovulation border. Results: The ovulation site is found to be usually accessible to the fimbrial end of the tube (94%) in the fertile cases and not accessible (92%) in the infertile cases. Correction of the fimbrio-ovarian relation in the infertile cases was associated with a cumulative ongoing pregnancy rate of 68%. Conclusion: Failed ovum pickup should be considered one of the important causes of unexplained infertility. The suggested "fimbrio-ovarian accessiblity" test may be useful for the elucidation of the state of ovum pickup in infertile cases. Correction of the fimbrio-ovarian relation, to make ovum pickup possible, should be considered a method for treating such cases. [source]

Development of pro, and antisaccades in children with attention,deficit hyperactivity disorder (ADHD) and healthy controls

PSYCHOPHYSIOLOGY, Issue 1 2003
C. H. Klein
To date, the investigation of the antisaccade task, a simple test of "executive functions," in children with ADHD has yielded inconsistent results. The present study aimed at contributing to this issue by (a) the investigation of a large sample of carefully diagnosed ADHD patients aged 7,15 years, and (b) the analyses of differential age effects in patients and controls. Healthy control children were pairwise matched with patients (N=46; age=136±24 months) for age and gender, and did not significantly differ in IQ. Horizontal pro, and antisaccades were elicited under the 200,ms gap and overlap conditions (blocks of 100 trials each). Overall, patients exhibited (a) augmented pro, and antisaccadic reaction times, (b) augmented error rates (antitasks), (c) augmented proportions of early responses (all conditions), and (d) reduced proportions of express saccades under the prosaccadic gap condition. The greater decline in anti, as compared to pro,SRT with increasing age that characterized controls was missing in patients. Confirming Barkley's (1997) neuropsychological theory of ADHD, these results altogether point to alterations in "executive Functions" in ADHD patients that are presumably supported by frontal lobe structures, in particular the lateral prefrontal cortex and the frontal eye fields. [source]

Testing for lack of dependence in the functional linear model

THE CANADIAN JOURNAL OF STATISTICS, Issue 2 2008
Piotr Kokoszka
Abstract The authors consider the linear model Yn = ,Xn + ,n relating a functional response with explanatory variables. They propose a simple test of the nullity of , based on the principal component decomposition. The limiting distribution of their test statistic is chi-squared, but this distribution is also an excellent approximation in finite samples. The authors illustrate their method using data from terrestrial magnetic observatories. Un test d'absence de dépendance dans un modéle fonctionnel linéaire Les auteurs s'intéressent au modèle Yn = ,Xn + ,n linéaire , liant une variable réponse fonctionnelle à des variables explicatives. Ils proposent un test simple de nullité, de fondé sur la décomposition en composantes principales. La loi limite de leur statistique est une khi-deux, mais cette loi fournit aussi une excellente approximation à taille finie. Les auteurs illustrent leur méthode au moyen de données provenant d'observatoires du champ magnétique terrestre. [source]

Simple Measures to Monitor ,-Cell Mass and Assess Islet Graft Dysfunction

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2007
R. N. Faradji
The aim of this study was to develop a simple test for the assessment of islet graft dysfunction based on measures involving fasting C-peptide. Calculations were made to account for the dependence of C-peptide secretion on glucose concentration (C-peptide/glucose ratio [CP/G]) and adjusted for renal function by calculating the C-peptide/glucose-creatinine ratio (CP/GCr). Values from 22 recipients were analyzed at different times post-last islet infusion. Receiver operating characteristic curves were used to determine which of these measures best predicts high 90-minute glucose (90 min-Glc; >10 mmol/L) after a Mixed Meal Tolerance Test (MMTT). In this initial analysis, CP/G was found to be superior predicting high 90 min-Glc with a larger area under the ROC curve than C-peptide (p = 0.01) and CP/GCr (p = 0.06). We then correlated C-peptide and CP/G with islet equivalents-IEQ/kg infused, 90 min-Glc after MMTT and clinical outcome (,-score). C-peptide and CP/G in the first 3 months post-last islet infusion correlated with IEQ/kg infused. CP/G correlated with 90 min-Glc and ,-score. C-peptide and CP/G are good indicators of islet mass transplanted. CP/G is more indicative of graft dysfunction and clinical outcome than C-peptide alone. The ease of calculation and the good correlation with other tests makes this ratio a practical tool when monitoring and managing islet transplant recipients. [source]

The concordance test emerges as a powerful tool for identifying quantitative trait nucleotides: lessons from BTA6 milk yield QTL

ANIMAL GENETICS, Issue 2 2009
E. Seroussi
Summary The lack of conventions for confirming the discovery of quantitative trait nucleotides in livestock was evidenced by the proposals of mutations in two different genes (SPP1 and ABCG2) as the underlying functional mutation for a major quantitative trait locus (QTL) for milk concentration on bovine chromosome 6 (BTA6). Of these conflicting candidates, SPP1 was excluded by follow-up studies and by the data described here. A simple test for concordance of the zygosity state between QTL segregation status and the candidate polymorphism was shown, in this case, to be a critical step towards establishing the proof. If a given sample effectively represents the genetic variation across the QTL region, haplotype-based concordance may further enhance the functionality and resolution power of this test, allowing identification of the causative gene. [source]

A simple test of exponentiality against NWBUE family of life distributions

APPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY, Issue 1 2005
M. Z. Anis
Abstract In this paper we propose a simple procedure to test the null hypothesis of exponentiality against the alternative that it belongs to the new worse then better than used in expectation (NWBUE) family. The test is shown to be consistent and the asymptotic distribution of the test statistic has been obtained. The performance of the test against various classes of alternatives has been studied by means of simulation. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Diagnosis of thrombotic thrombocytopenic purpura based on modulation by patient plasma of normal platelet adhesion under flow condition

BRITISH JOURNAL OF HAEMATOLOGY, Issue 4 2003
Boris Shenkman
Summary. We have designed a simple test for the early diagnosis and treatment monitoring of thrombotic thrombocytopenic purpura (TTP). We examined plasma from 24 TTP patients and normal plasma using a cone and plate(let) analyser (CPA). Test plasma was mixed with citrated normal whole blood (group O) and subjected to flow at a shear rate of 1800/s. Mixing normal plasma (12·5, 25, 50 or 75 µl) with heterologous normal whole blood (final volume of 200 µl) resulted in a decrease of surface coverage (SC, maximally by 63%) and, to a lesser extent, of average size (AS, maximally by 37%) due to dilution of the blood sample. In contrast, mixing the same quantities of acute TTP plasma with normal blood yielded an increase in both SC (up to 125%) and AS (up to 130%). Increased SC and/or AS were detected in all 15 patients in acute phase and in three out of 14 patients in remission. Following repeated plasmapheresis, the enhanced platelet deposition in five patients with acute TTP returned to almost normal patterns. Mixing plasma from patients with other thrombocytopenic conditions in this way resulted in a decrease in both SC and AS, and did not differ from control subjects. In conclusion, the CPA is a simple and specific laboratory test that can be used for the diagnosis and monitoring of plasma exchange therapy in TTP. [source]

Delirium in acute stroke , prevalence and risk factors

ACTA NEUROLOGICA SCANDINAVICA, Issue 2010
M. H. Dahl
Dahl MH, Rønning OM, Thommessen B. Delirium in acute stroke , prevalence and risk factors. Acta Neurol Scand: 2010: 122 (Suppl. 190): 39,43. © 2010 John Wiley & Sons A/S. Background,,, Delirium is frequently seen as a major complication among elderly stroke patients. Few studies have prospectively studied delirium as a complication of acute stroke. In these studies, the results are conflicting regarding risk factors and estimated prevalence. The aims of the present study are to assess the prevalence of delirium in patients with acute stroke treated in an acute Stroke Unit, identify characteristics of patients with delirium and important factors associated with the development of delirium. Methods,,, We conducted a prospective study of patients with delirium and acute stroke consecutively admitted to a Stroke Unit. The diagnosis of delirium was based on Confusion Assessment Method (CAM). CAM is devised from DSM-III-R criteria based on the diagnosis of delirium, and is a simple test with high sensitivity and specificity. Results,,, One hundred and seventy-eight patients with a diagnosis of stroke were eligible for the study. The prevalence of delirium in acute stroke in our study was 10% (18 of 178 patients). Patients with delirium had significantly longer length of stay in the Stroke Unit (12.3 vs 8.5 days, P < 0.004). Prestroke dementia [odds ratio (OR) 18.7], hemianopsia (OR 12.3), apraxia (OR 11.0), higher age (OR 5.5) and infection (UTI or pneumonia) (OR 4.9) during in-hospital stay were associated with increased risk of delirium. Conclusion,,, One of 10 stroke patients had delirium. This is the lowest prevalence of delirium shown in acute stroke patients. In our study, all patients were treated in a Stroke Unit. A Stroke Unit like the Scandinavian model may be beneficial in preventing delirium. [source]

Predicting Cognitive Impairment in High-Functioning Community-Dwelling Older Persons: MacArthur Studies of Successful Aging

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 6 2002
Joshua Chodosh MD, MSHS
OBJECTIVES: To examine whether simple cognitive tests, when applied to cognitively intact older persons, are useful predictors of cognitive impairment 7 years later. DESIGN: Cohort study. SETTING: Durham, North Carolina; East Boston, Massachusetts; and New Haven, Connecticut, areas that are part of the National Institute on Aging Established Populations for Epidemiological Studies of the Elderly. PARTICIPANTS: Participants, aged 70 to 79, from three community-based studies, who were in the top third of this age group, based on physical and cognitive functional status. MEASUREMENTS: New onset of cognitive impairment as defined by a score of less than 7 on the Short Portable Mental Status Questionnaire (SPMSQ) in 1995. RESULTS: At 7 years, 21.8% (149 of 684 subjects) scored lower than 7 on the SPMSQ. Using multivariate logistic regression, three baseline (1988) cognitive tests predicted impairment in 1995. These included two simple tests of delayed recall,the ability to remember up to six items from a short story and up to 18 words from recall of Boston Naming Test items. For each story item missed, the adjusted odds ratio (AOR) for cognitive impairment was 1.44 (95% confidence interval (CI) = 1.16,1.78, P < .001). For each missed item from the word list, the AOR was 1.20 (95% CI = 1.09,1.31, P < .001). The Delayed Recognition Span, which assesses nonverbal memory, also predicted cognitive impairment, albeit less strongly (odds ratio = 1.06 per each missed answer, 95% CI = 1.003,1.13, P = .04). CONCLUSIONS: This study identifies measures of delayed recall and recognition as significant early predictors of subsequent cognitive decline in high-functioning older persons. Future efforts to identify those at greatest risk of cognitive impairment may benefit by including these measures. [source]

A general model of the public goods dilemma

JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 6 2010
S. A. Frank
Abstract An individually costly act that benefits all group members is a public good. Natural selection favours individual contribution to public goods only when some benefit to the individual offsets the cost of contribution. Problems of sex ratio, parasite virulence, microbial metabolism, punishment of noncooperators, and nearly all aspects of sociality have been analysed as public goods shaped by kin and group selection. Here, I develop two general aspects of the public goods problem that have received relatively little attention. First, variation in individual resources favours selfish individuals to vary their allocation to public goods. Those individuals better endowed contribute their excess resources to public benefit, whereas those individuals with fewer resources contribute less to the public good. Thus, purely selfish behaviour causes individuals to stratify into upper classes that contribute greatly to public benefit and social cohesion and to lower classes that contribute little to the public good. Second, if group success absolutely requires production of the public good, then the pressure favouring production is relatively high. By contrast, if group success depends weakly on the public good, then the pressure favouring production is relatively weak. Stated in this way, it is obvious that the role of baseline success is important. However, discussions of public goods problems sometimes fail to emphasize this point sufficiently. The models here suggest simple tests for the roles of resource variation and baseline success. Given the widespread importance of public goods, better models and tests would greatly deepen our understanding of many processes in biology and sociality. [source]

Methods of studying the planar distribution of objects in histological sections of brain tissue

JOURNAL OF MICROSCOPY, Issue 3 2006
R. A. ARMSTRONG
Summary This article reviews the statistical methods that have been used to study the planar distribution, and especially clustering, of objects in histological sections of brain tissue. The objective of these studies is usually quantitative description, comparison between patients or correlation between histological features. Objects of interest such as neurones, glial cells, blood vessels or pathological features such as protein deposits appear as sectional profiles in a two-dimensional section. These objects may not be randomly distributed within the section but exhibit a spatial pattern, a departure from randomness either towards regularity or clustering. The methods described include simple tests of whether the planar distribution of a histological feature departs significantly from randomness using randomized points, lines or sample fields and more complex methods that employ grids or transects of contiguous fields, and which can detect the intensity of aggregation and the sizes, distribution and spacing of clusters. The usefulness of these methods in understanding the pathogenesis of neurodegenerative diseases such as Alzheimer's disease and Creutzfeldt-Jakob disease is discussed. [source]

Comparison of simple tests for the non-invasive diagnosis of clinically silent cirrhosis in chronic hepatitis C

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 5 2006
G. BORRONI
Summary Background Biopsy is the gold standard for assessing cirrhosis in patients with chronic hepatitis C virus infection, but it is expensive and at risk of complications. Alternative non-invasive methods have been developed but their usefulness remains uncertain. Aim To compare the accuracy of five non-invasive scores in detecting cirrhosis. Methods We reviewed the charts and liver biopsies of 228 consecutive, treatment-naïve, hepatitis C virus-positive patients, 13.2% of whom with histological diagnosis of cirrhosis. The five alternative scores were age-platelet index, cirrhosis discriminant score, aspartate transaminases to platelet ratio index, Pohl's index, and aspartate transaminases/alanine transaminases ratio. Results The specificities of the scores were good (87,100%), but not so their sensitivities (17,67%). Accordingly positive likelihood ratios were generally good but negative likelihood ratios were suboptimal. Combinations of the scores independently related to cirrhosis only slightly change this diagnostic accuracy. Using double cut-offs to exclude/diagnoses cirrhosis, cirrhosis discriminant score classified 21% of patients without misdiagnoses and aspartate transaminases to platelet ratio index classified 85% of case with 9% of misdiagnoses. Conclusions The five scores showed variable sensitivities and specificities in detecting liver cirrhosis, both individually and in combination. The use of double cut-off points may make the cirrhosis discriminant score and aspartate transaminases to platelet ratio index useful to reduce the number of patients submitted to liver biopsy. [source]

Some Simple Tests for Spatial Effects Around Putative Sources of Health Risk

Preterm premature rupture of membranes: diagnosis, evaluation and management strategies

BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 2005
Hyagriv N. Simhan
Preterm premature rupture of the membranes (PPROM) is responsible for one-third of all preterm births and affects 120,000 pregnancies in the United States each year. Effective treatment relies on accurate diagnosis and is gestational age dependent. The diagnosis of PPROM is made by a combination of clinical suspicion, patient history and some simple tests. PPROM is associated with significant maternal and neonatal morbidity and mortality from infection, umbilical cord compression, placental abruption and preterm birth. Subclinical intrauterine infection has been implicated as a major aetiological factor in the pathogenesis and subsequent maternal and neonatal morbidity associated with PPROM. The frequency of positive cultures obtained by transabdominal amniocentesis at the time of presentation with PPROM in the absence of labour is 25,40%. The majority of amniotic fluid infection in the setting of PPROM does not produce the signs and symptoms traditionally used as diagnostic criteria for clinical chorioamnionitis. Any evidence of infection by amniocentesis should be considered carefully as an indication for delivery. Documentation of amniotic fluid infection in women who present with PPROM enables us to triage our therapeutic decision making rationally. In PPROM, the optimal interval for delivery occurs when the risks of immaturity are outweighed by the risks of pregnancy prolongation (infection, abruption and cord accident). Lung maturity assessment may be a useful guide when planning delivery in the 32- to 34-week interval. A gestational age approach to therapy is important and should be adjusted for each hospital's neonatal intensive care unit. Antenatal antibiotics and corticosteroid therapies have clear benefits and should be offered to all women without contraindications. During conservative management, women should be monitored closely for placental abruption, infection, labour and a non-reassuring fetal status. Women with PPROM after 32 weeks of gestation should be considered for delivery, and after 34 weeks the benefits of delivery clearly outweigh the risks. [source]