bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multivariate Analyses of Blood Pressure Related Phenotypes in a Longitudinal Framework: Insights From Genetic Analysis Workshop 18
Authors: Ghosh Saurabh 
Published: August 2014

ABSTRACTOur working group studied methods for joint analyses of multiple phenotypes using the data provided by Genetic Analysis Workshop 18. Two data sets were available: one containing genotypes obtained from a real human whole‐genome sequencing study along with longitudinal measurements on systolic and diastolic blood pressure, age, sex, medication use, and tobacco smoking; and the other a simulated data set using the same set of genotypes and phenotype structure as the real data set. The nine sets of investigators in our working group focused on the statistical challenges posed by association analyses of multivariate phenotypes; they applied a wide spectrum of statistical methods, such as linear mixed models, copula models, and semiparametric regression models for simultaneous analyses of longitudinal data on the two blood pressure phenotypes at the genome‐wide level. In this report, we discuss the various strategies explored by the different investigators whose common goal was improving the power to detect association with multivariate phenotypes.
BDNF contributes to the facilitation of hippocampal synaptic plasticity and learning enabled by environmental enrichment
Authors: Novkovic Tanja , Mittmann Thomas , Manahan‐Vaughan Denise 
Published: August 2014

ABSTRACTSensory, motor, and cognitive stimuli, resulting from interactions with the environment, play a key role in optimizing and modifying the neuronal circuitry required for normal brain function. An experimental animal model for this phenomenon comprises environmental enrichment (EE) in rodents. EE causes profound changes in neuronal and signaling levels of excitation and plasticity throughout the entire central nervous system and the hippocampus is particularly affected. The mechanisms underlying these changes are not yet fully understood. As brain‐derived neurotrophic factor (BDNF) supports hippocampal long‐term potentiation (LTP), we explored whether it participates in the facilitation of synaptic plasticity and hippocampus‐dependent learning that occurs following EE. In the absence of EE, LTP elicited by high‐frequency stimulation was equivalent in wildtype mice and heterozygous BDNF+/− siblings. LTP elicited by theta‐burst stimulation in BDNF+/− mice was less than in wildtypes. Long‐term depression (LTD) was also impaired. EE for three weeks, beginning after weaning, improved hippocampal LTP in both wildtype and transgenic animals, with LTP in transgenics achieving levels seen in wildtypes in the absence of EE. Object recognition memory was evident in wildtypes 24 h and 7 days after initial object exposure. EE improved memory performance in wildtypes 24 h but not 7 days after initial exposure. BDNF+/− mice in the absence of EE showed impaired memory 7 days after initial object exposure that was restored by EE. Western blotting revealed increased levels of BDNF, but not proBDNF, among both EE cohorts. These data support that BDNF plays an intrinsic role in improvements of synaptic plasticity and cognition that occur in EE. © 2014 The Authors. Hippocampus Published by Wiley Periodicals, Inc.
Identifying barriers to move to better health coverage: preferences for health insurance benefits among the rural poor population in La Guajira, Colombia
Authors: Amaya Jeannette Liliana , Ruiz Fernando , Trujillo Antonio J. , Buttorff Christine 
Published: August 2014

SUMMARYEven though access to health insurance in Colombia has improved since the implementation of the 1993 health reforms (Law 100), universal coverage has not yet been accomplished. There is still a segment of the population under the low‐income (subsidized) health insurance policy or without health insurance altogether. The purpose of this research was to identify preferences and behavior regarding health insurance among the subsidized rural population in La Guajira, Colombia, and to understand why that population remains under the subsidized health insurance policy. The field experiment gathered information from 400 households regarding their socioeconomic situation, health conditions, and preferences for health insurance characteristics. Results suggest that the surveyed population gives priority to expanded family coverage, physician and hospital choice, and access to specialists, rather than to attributes associated with co‐payments or premiums. That indicates that people value healthcare benefits and family coverage more than health insurance expenses, and policy makers could use these preferences to enroll subsidized population into the contributory regime. Copyright © 2014 John Wiley & Sons, Ltd.
Anticonvulsants to treat post‐traumatic stress disorder
Authors: Wang Hee Ryung , Woo Young Sup , Bahk Won‐Myong 
Published: August 2014

ObjectiveWe reviewed the existing literature on the efficacy of anticonvulsants in treating post‐traumatic stress disorder.MethodsWe performed a literature search using PubMed, EMBASE and the Cochrane database on 30 September 2013. Randomized, controlled studies that investigated the efficacy of anticonvulsants for post‐traumatic stress disorder were included in this review. Studies with retrospective designs, case reports and case series were excluded.ResultsA total of seven studies met the inclusion criteria for this review. Three studies used topiramate with negative findings regarding its efficacy. Two studies used divalproex, both of which failed to show superiority over placebo. One study used lamotrigine, with favourable results, and one study used tiagabine, with negative results.ConclusionsFuture long‐term studies with larger sample sizes are needed to investigate the clinical utility of anticonvulsants for post‐traumatic stress disorder treatment. Copyright © 2014 John Wiley & Sons, Ltd.
REPORT ON THE VALIDATION OF TESTS AGAINST FIRST AND SECOND TERM GRADES AND QUALITY‐POINT RATIOS AT THE U. S. NAVAL POSTGRADUATE SCHOOL (JULY 1948 TESTING)
Authors: Mollenkopf William G. 
Published: August 2014

ABSTRACTScores on the 20 aptitude and achievement tests given in July 1948 have been correlated with each other and with first and second term grades at the Naval Postgraduate School. The following tests correlated higher than .40 with the criterion of Quality‐Point Ratio for both of the terms: (1) Engineering Achievement Test in Mathematics, (2) Physics SA, (3) the Graduate Record Examination Advanced Test in Engineering, (4) Reading Comprehension, (5) Mathematics WSA2, and (6) Mathematics WIM3. Several other tests showed significant but lesser degrees of validity for predicting the Q.P.R. or one or more course grades.The technique of multiple correlation was also used, and shewed that mathematics and engineering wore the two areas which contributed most heavily to the prediction of grades in the first two terms.Item analyses of the mathematics, engineering and physics tests have been carried out as an aid to further test development.Results for the first two terms have been very encouraging and indicate that initial efforts to predict academic success at the Naval Postgraduate School have been quite fruitful.
VALIDITIES OF TESTS GIVEN IN JULY 1948 FOR PREDICTING FIRST YEAR AVERAGE GRADES AT THE U. S. NAVAL POSTGRADUATE SCHOOL
Authors: Mollenkopf William G. 
Published: August 2014

ABSTRACTScores on the twenty aptitude and achievement tests administered in July 1948 to the incoming class at the U. S. Naval Postgraduate School have been related to the quality‐point ratios of the officers in this class for their entire first year. Charts have been prepared showing for each of four score intervals on each test the percentage of students having such test scores who earned quality point ratios above 2.00. Also, product‐moment coefficients of correlation between scores on each test and the criterion of quality‐point ratios have been computed.Examination of the charts and consideration of the correlations presented in this report reveal that the tests which showed high relationships with the academic grades were those in mathematical aptitude end mathematical achievement, engineering, reading comprehension, and physics.It was concluded that a very premising start has been made on the task of developing a battery of tests suitable for use as part of the means of selecting students for the Naval Postgraduate School.
PREDICTED DIFFERENCES AND DIFFERENCES BETWEEN PREDICTIONS
Authors: Mollenkopf W. G. 
Published: August 2014

ABSTRACTWhen K tests are given to N individuals, and for each individual there are available two criterion measures, then (1) the multiple regression weight to be applied to the standard score for each test to predict the criterion‐difference score is equal to the difference of the weights for predicting each criterion separately; (2) the difference between the predicted scores for the two criteria is the same as the predicted difference in criterion scores (each test being assigned the appropriate multiple regression weight); (3) the square of the multiple correlation between predicted and actual criterion‐difference scores is equal to the sum of the squares of the multiple correlations of the battery with each criterion, less the product of these correlations and the correlation between predicted scores, all divided by twice the quantity one minus the criterion intercorrelation; and (4) the variance of the errors of estimating the criterion‐difference score is equal to the sum of the variances of the errors of estimating each criterion score, minus twice the criterion intercorrelation, plus twice the correlation between predicted scores multiplied by the product of the square root of one minus the variance of the errors of estimating one criterion and the corresponding square root for the second criterion.
A FACTOR ANALYSIS OF ENGLISH ESSAY READERS
Authors: Torgerson Warren S. , Green Bert F. 
Published: August 2014

ABSTRACTInverted multiple factor analysis is used to examine a 20 × 20 matrix of correlations of English essay readers, based on 38 essays. A large general factor indicates considerable agreement among the readers. Three weak group factors suggest the existence of consistent schools of thought concerning the quality of English essays although it is possible that they are due to chance groupings. The intrinsic validity of an achievement test is discussed in relation to inverted factor analysis.
THE RELIABILITY OF SPEEDED TESTS
Authors: Gulliksen Harold 
Published: August 2014

ABSTRACTSome methods are presented for estimating the reliability of a partially speeded test without the use of a parallel form. The effect of these formulas on some test data is illustrated. Whenever an odd‐even reliability is computed, it is probably desirable to use one of the formulas noted in Section 2 of this paper in addition to the usual Spearman‐Brown correction. Since the formulas given here involve the mean and standard deviation of the “number unattempted score”, a method is given in Section 4 for computing this mean and standard deviation from item analysis data. If the item analysis data are available, this method will save considerable time as compared with rescoring answer sheets.
A TEST OF THE EQUALITY OF STANDARD ERRORS OF MEASUREMENT
Authors: Green Bert F. 
Published: August 2014

ABSTRACTA procedure is proposed for testing the significance of group differences in the standard error of measurement of a psychological test. Wilks' criterion is used to assure that the tests used in ascertaining reliability and hence variance of errors of measurement may be assumed parallel for each group. Votaw's criterion may be used to check whether the test scores of all the groups have the same mean, variance, and covariance. It is possible, however, for the variance and reliability of the test to differ widely from group to group, so that Votaw's criterion is not satisfied, even though the variance of errors of measurement stays relatively constant. For this case a modification of Neyman and Pearson's criterion is developed to test agreement among standard errors of measurement despite group differences in mean, variance, and reliability of the test.
THE LAW SCHOOL ADMISSION TEST AS A PREDICTOR OF LAW SCHOOL GRADES*
Authors: Schrader W. B. , Olsen M. A. 
Published: August 2014

SUMMARY AND CONCLUSIONSThe effectiveness of the Law School Admission Test (LSAT) as a predictor of first‐year law school grades grades was evaluated in a series of studies initiated in the summer of 1949. This report is based on the findings of studies is eighteen law schools, including twelve schools which provided data on some measure of the previous academic success of their students. The eighteen law schools on which this report is based include all schools now represented on the Policy Committee of the Law School Admission Test which had test scores on 25 or more students.The principal finding of this study is that Law School Admission Test scores are distinctly useful alone or preferably as supplementary to evidence of previous academic success in predicting first‐year grades of law students. This conclusion, is based on the fact than the predictive effectiveness of the combined predictors is represented by a correlation coefficient of .52, as compared with a value of .40 for the test alone and of .38 for previous academic success alone. These figures summarize results based on 1725 day students in 12 law schools. In ten of those twelve schools the test score equalled or excelled the college record as a predictor of first‐year lay grades.The Law School Admission Teal had a validity coefficient of .44 based on the pooled results from 18 groups of day students and three groups of evening students. A coefficient of this size indicates definite usefulness in prediction of graces for the best used alone. It would reasonably be expected that the coefficients obtained would have been higher if the students had net been selected, at least in part, on the basis of test scores.In a number of law schools, attention was given to the possibility that the number of years of pre‐law college work might be considered an additional determiner in predicting success. It was found, however, that no appreciable gains in predicting success could be obtained by using this information. Similarly, it was found that no appreciable gain in prediction could be obtained by taking into account whether or not the student had received his undergraduate education at the same university in which he was attending law school.
A COMPARISON OF ADMITTED AND NON‐ADMITTED GROUPS AT THE U. S. NAVAL POSTGRADUATE SCHOOL
Authors: Mollenkopf William G. 
Published: August 2014

ABSTRACTIn the fall of 1948 the five‐part Naval Postgraduate School Aptitude Test Form WNPF was administered at shore installations and on ships to applicants for admission to the Postgraduate School. Test data for those later admitted to the School have now been compared with similar data for those who were not selected, to allow comparisons of the applicant and admitted groups and to estimate the effects of the present selection process on the magnitudes of the test validities being obtained in the experimental test‐development program being carried on at the Postgraduate School.It was found that the greatest reduction in range of talent had occurred for the Mathematics Aptitude part of the test, and, as a consequence, that the validity of this part was most markedly affected by the selection process. Lesser effects were noted for the Beading Comprehension, Spatial Intersections, and Physics parts of the test. No reduction in range of talent was observed for the Verbal Antonyms part, and since it seems probable that the validity of this test is not seriously affected by the selection process, its observed low validity may be concluded not to be a result of rigorous selection on verbal ability.It was concluded that in the future interpretation of test validities, the fact must be taken into account that the present method of selection restricts the range of ability in mathematics aptitude somewhat more than in other areas. Observed validities for mathematics tests are therefore likely to have been lowered more by the selection process than those of other tests involved in the study.
PROPERTIES OF TEST SCORES EXPRESSED AS FUNCTIONS OF THE ITEM PARAMETERS
Authors: Lord Frederic M. 
Published: August 2014

ABSTRACTThe bivariate distribution of test scores and scores on the common factor of the test items is derived as a mathematical function of the usual item parameters for the case where
the test score is the number of items answered “correctly”;
the multivariate distribution of responses to the test items is of such a nature that it could have arisen from a normal multivariate distribution of abilities in the group of examinees tested (an alternative condition is that the item characteristic curve is a normal ogive);
the matrix of tetrachoric item intercorrelations has a rank of 1.
It is always possible to check empirically whether or not any given set of actual data conforms to these conditions.Mathematical expressions are presented for
the univariate frequency distribution of the test scores;
the standard error of measurement for examinees at any given level of ability;
the regression of test scores on ability;
an index of the discriminating power of the test for individuals at any given level of ability.
The measure of “ability” is here taken to be the common factor score. (It may be shown that for an infinitely long test the common factor score is identical with normalized true score.)The following generalizations are made from the formulas:1) the regression of test score on ability score is never linear, although under certain conditions it may be approximately so;2) rectangular and U‐shaped distributions of test score may be obtained if the items have tetrachoric intercorrelations of 0.50 or more;3) the standard error of measurement is smallest for those individuals for whom the test is least discriminating;4) if a test is to be used only for selection or rejection of the examinees, all items should be of equal difficulty.
DEVELOPMENT OF PERSONALITY TESTS FOR NAVAL OFFICER SELECTION I. ANALYSIS OF U. S. NAVAL ACADEMY CRITERION OF APTITUDE FOR SERVICE
Authors: Ricciuti Henry No , French John V. 
Published: August 2014

ABSTRACTThe objective of this research is the development of personality measures to supplement the more scholastically oriented aptitude tests used in the selection of Naval officers. The first year's work, recently completed, was concerned with a study of associates' and officers' ratings of U. S. Naval Academy midshipmen on “aptitude for service,” or leadership potential. Intercorrelations were computed among aptitude for service ratings for three summer cruises and two academic periods, standings in academic courses, and scholastic aptitude test scores, using 633 members of the class of 1951. Results indicated that the aptitude ratings were quite clearly differentiated from academic standing, and from verbal, mathematical, and spatial ability. Considerable stability was found in the ratings from one marking period to another, except for cruise ratings.A more detailed analysis of the ratings given and received by about 200 midshipmen from the larger group indicated that the composite ratings by fellow midshipmen were highly reliable. There was some evidence indicating a slight tendency for raters who agreed with composite opinion in judging their associates, to stand high themselves in aptitude for service. Little or no relationship was found between aptitude for service and a number of biographical factors such as age, previous military service, amount and type of previous education, etc.On the basis of the first year's work, it was felt that the aptitude ratings represented a suitable first criterion, and hence it was considered advisable and worth‐while to proceed with the development and initial validation of personality measures to predict this criterion. This constitutes the objective of the second phase of the investigation which was recently initiated. Work is underway on the development of personality tests deemed to be most appropriate or promising in the light of what has been learned about the aptitude ratings during the first phase of the research.
EFFECTIVENESS OF NAVAL ACADEMY DEPARTMENTAL STANDINGS FOR PREDICTING ACADEMIC SUCCESS AT THE U.S. NAVAL POSTGRADUATE SCHOOL
Authors: Mollenkopf William G. 
Published: August 2014

ABSTRACTFive Naval Academy course standings have been evaluated for their effectiveness in adding to the prediction of quality‐point ratios at the Naval Postgraduate School obtainable from the experimental tests developed for the School by the Educational Testing Service. Five groups of students were included in the study: first‐year students tested in 1948, second‐year students tested in 1948, first‐year students tested in 1949, second‐year students tested in 1949, and first‐year students tested in 1950.For every one of the groups, the course standings added to the effectiveness of the tests alone, raising the multiple correlation by at least several points. In four out of five groups, the course standing found to be the one to make this added contribution to validity was that in Marine Engineering.It was recommended that in choosing students for admission to the School, the course standing in Marine Engineering be given equal relative weight to that given to the score on the selection test.
THE VALIDITY OF SOME OBJECTIVE PERSONALITY TESTS FOR A LEADERSHIP CRITERION
Authors: French John W. 
Published: August 2014

ABSTRACTEight objective tests developed to measure personality characteristics were given to entering cadets at the U. S. Coast Guard Academy in the summer of 1949. It was hoped that some of these would be found to relate to the ratings of leadership potential made at the Academy. These tests and the rationales for them are described. The results are presented in the form of intercorrelations among a total of 19 scores on the 8 tests, 2 academic entrance examination scores, 2 leadership ratings, and average course grades. The results are slightly, but only slightly, encouraging for some of the tests. Criterion‐keying and cross‐validation was performed for some of the tests, again with results that can be considered just slightly encouraging.
PREDICTION OF SECOND‐YEAR AND THIRD‐YEAR GRADE‐POINT AVERAGES AT THE U. S. NAVAL POSTGRADUATE SCHOOL
Authors: Mollenkopf William G. 
Published: August 2014

ABSTRACTFurther validation of the 20 aptitude and achievement tests given in 1948 and of the 12 tests given to the group entering the Postgraduate School in 1949 has been carried out. The 1948 test scores have been related to quality‐point ratios for the entire second year and for the first two terms of the third year, both by bar charts depicting the per cent of students in each third of the score range on each test who achieved a 2.0 quality‐point ratio or above, and also by means of product‐moment coefficients of correlation. For the 1948 tests, mean test scores of drop‐outs from the School were also compared with mean scores for those continuing in Postgraduate work. Similarly bar charts were prepared and product‐moment coefficients of correlation were computed for the 1949 tests.While the phenomenon of shrinkage in test validities from first to second year previously observed, with the 1948 tests also was found with the 1949 tests, the shrinkage was not as great. Also, the validities of 1948 tests against third‐year grade‐point ratios tended to be somewhat higher than those for the second year.It was concluded on the basis of the findings that tests of advanced mathematics, mathematics aptitude, physics, and engineering are effective for predicting success at the Postgraduate School as judged by all three of the techniques employed for assessing the tests.