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B A Bailey

Publications and source records attributed to B A Bailey.

At least 19 recordsLinked to original sources
PubMed2003

A model for failure of a chicken embryo to survive incubation.

Proper assessment of factors contributing to failure of an egg to hatch, i.e., infertility and embryonic mortality, is important in poultry production. A model consisting of the sum of two cumulative logistic distributions was proposed previously to describe the distribution for time of mortality during incubation; model parameters, including probabilities of infertility and mortality, were estimated by the method of least squares. The objective of this paper was to improve the previous model and method of estimation by evaluating alternative distributions and methods; we propose four recommendations. First, probabilities of infertility and mortality should be estimated as observed proportions rather than as model parameters. Second, parameters of the distribution for time of mortality should be estimated using a diphasic Weibull distribution rather than a diphasic logistic distribution. Third, parameters of the distribution for time of mortality should be estimated using noncumulative proportions rather than cumulative proportions. Fourth, parameters of the distribution for time of mortality should be estimated by maximum likelihood rather than by least squares. The minimum Hellinger distance, however, is a good alternative to maximum likelihood to estimate distribution parameters if the distribution of mortality is not known exactly or if the data contain outliers.

Animals↗
PubMed2002

Influence of storage days on the distribution for time of embryonic mortality during incubation.

Breakout analysis of 11,254 chicken eggs that failed to hatch was used to assess the influence of storage days on the distribution for time of embryonic mortality during incubation and on reproductive efficiency. Eggs were collected over 30 d, stored from 2 through 18 d, and incubated in two hatches. For each storage day within hatch, proportions of embryonic mortality during each of the 21 d of incubation, among embryos that did not survive incubation, were fitted by a diphasic Weibull distribution. Multivariate analysis was used to assess the influence of hatch and storage days within hatch on parameters of the distribution and on two measures of reproductive efficiency, proportions of embryonic mortality during incubation among all eggs incubated P(mort) and among fertile eggs incubated P(mort/fert), and to obtain partial correlation coefficients. Storage days influenced the distribution for time of embryonic mortality in each hatch, but the effect was different for each hatch. As the number of storage days increased, P(mort) and P(mort/fert) increased. Partial correlations showed that P(mort) and P(mort/fert) decreased as the proportion of embryos that died during the first phase decreased and as duration of the second phase increased. The shape of the distribution for time of mortality during incubation influenced reproductive efficiency. Factors that influence the shape of this distribution, other than hatch and storage days within hatch, should be studied to increase reproductive efficiency in the poultry industry.

Animals↗
PubMed2001

Effect of hatch on the distribution for failure of an embryo to survive incubation.

The objectives of this paper were to validate an improved model to describe failure to hatch by using data obtained from two hatches of a line of chickens and to examine the effect of hatch on the distribution for time of failure of an embryo to survive incubation. Breakout analysis of 11,254 eggs that failed to hatch was used to characterize the distribution for time of failure to survive and the probability of failure to hatch. The distribution for time of failure to survive was modeled by a diphasic Weibull distribution, corresponding to the two phases of increased embryonic mortality during incubation. Distribution parameters for time of failure to survive were estimated by maximum likelihood and minimum Hellinger distance. Goodness-of-fit statistics validated the appropriateness of the diphasic Weibull distribution. Overall, the proportion of infertility was 0.213, and the proportion of embryonic mortality by the end of incubation was 0.086. Among embryos that suffered mortality during incubation, the proportion that died during Phase 1 was 0.77; therefore, 0.23 died during Phase 2. For Phase 1, mean time of mortality was 2.6 d, and standard deviation was 3.3 d. For Phase 2, mean time was 17.4 d, and standard deviation was 2.0 d. Time of mortality was distributed differently in the two hatches; this difference occurred mostly during Phase 1. Failure rates of the two hatches were different during the first 3 d of incubation. The model is useful to assess probability of failure to hatch and the distribution for time of failure to survive during incubation.

Animals↗
PubMed2000

L-type Ca2+ channel alpha 1c subunit isoform switching in failing human ventricular myocardium.

UNLABELLED: The objectives of this study were to determine the relative abundance of the L-type Ca channel alpha 1c IVS3 isoforms that result from alternative splicing in normal human ventricular myocytes and to measure the changes in isoform expression in end stage heart failure. METHODS: mRNA was isolated from left ventricular tissue and myocytes from non-failing and failing human hearts. RT-PCR with isoform-specific primers was used to obtain cDNAs that were then mutated for use in competitive PCR reactions. An RNase protection assay was also used to confirm the presence of one of the novel isoforms. RESULTS: Four different alpha 1c IVS3 isoforms were found in non-failing human ventricular myocytes using RT-PCR. Two isoforms contained exon 31 (termed IVS3A isoforms) and two isoforms contained exon 32 (termed IVS3B isoforms). One of these isoforms has not been observed previously and contains exon 31 and all but the last six base pairs of exon 32. In non-failing human ventricular myocytes the IVS3A isoform is 2.5 times more abundant than the IVS3B isoform. There were significant changes in the relative abundance of these isoforms in failing hearts, with the IVS3B isoform being twice as abundant as the IVS3A isoform. All isoforms were confirmed by RNase protection analysis. CONCLUSIONS: These experiments show that there are at least four L-type Ca channel mRNA isoforms in the normal human heart and that the relative abundance of these isoforms changes significantly in heart failure. These alpha 1c isoform changes in heart failure are associated with dysfunctional electromechanical disturbances, but the specific physiological role of each L-type Ca channel isoform in normal and failing hearts needs to be defined.

Adult↗
PubMed1997

Cellular basis of contractile derangements of hypertrophied feline ventricular myocytes.

The objective of this study was to further explore the cellular basis of the reduced rate and magnitude of contraction of feline left ventricular myocytes with severe hypertrophy induced by slow progressive pressure overload. A 3.0 mm internal diameter band was placed around the ascending aorta of 12 young (8-10 weeks old) cats, and sham operations were performed in 13 others. This caused no major pressure overload initially, but 15 weeks later there was a significant pressure gradient across the band (56+/-14 mmHg) and the heart weight to body weight ratio had increased from 4.2-7 gm/kg. Contraction rates and magnitudes of myocytes isolated from the hearts with hypertrophy (LVH) were significantly slower and smaller, respectively, than those from control (C) animals. Indo-1 fluorescence transients in LVH myocytes were significantly smaller in magnitude and longer in duration than in C, suggesting that contractile defects result from Ca2+ derangements. Elevation of bath Ca2+ increased the peak Indo-1 fluorescence and the rate and magnitude of contraction in all myocytes. At the bath Ca2+ which had maximal inotropic effects there were no differences in the peak Indo-1 fluorescence in LVH and C myocytes, but contraction magnitude remained significantly smaller in LVH. This suggests that there are Ca2+-independent contractile derangements in LVH. In support of this hypothesis, the relationship between contraction magnitude and the peak Indo-1 fluorescence (index of myofibrillar Ca2+ sensitivity) was significantly shifted in LVH myocytes, suggesting that myofibrillar Ca2+ sensitivity was reduced. There was also a significant shift of the terminal portions of hysteresis loops of cell length v indo-1 fluorescence ratio, providing additional support for this idea. Experiments with isoproterenol suggest that it can reduce myofibrillar Ca2+ sensitivity in C, but not LVH myocytes. The idea that increased internal resistance to shortening (internal load) is responsible for the contractile defects of LVH myocytes was examined by defining the relationship between the rate of relengthening and the magnitude of shortening. There was no significant difference in this relation between C and LVH myocytes. In addition, colchicine (which depolymerizes microtubular tubulin) had no significant effect on contraction magnitude in either C or LVH myocytes. These results suggest that the contractile properties of feline LVH myocytes result from changes in cellular Ca2+ regulation and myofibrillar Ca2+ sensitivity, but not from changes in the internal loading.

Actin Cytoskeleton↗
PubMed1997

The 24-kDa protein from Fusarium oxysporum f.sp. erythroxyli: occurrence in related fungi and the effect of growth medium on its production.

A 24-kDa protein that elicits ethylene production and necrosis in leaves of dicotyledonous plants was previously purified from culture filtrates of Fusarium oxysporum Schlechtend:Fr. f.sp. erythroxyli. Antisera to the denatured 24-kDa protein detected 2.5 ng of the 24-kDa protein on Western blots at 100000-fold dilutions. The antisera cross-reacted with a 24-kDa protein on Western blots of culture filtrates from three other F. oxysporum formae speciales. Of seven Fusarium species, only F. oxysporum, F. acuminatum Ellis and Kellerm., and F. avenaceum (Fr.:Fr.) Sacc. isolates produced an antigenically related 24-kDa protein. Although there were differences in the profiles of proteins extracted from stems of coca (Erythroxylum coca var. coca L. Lam.) infected with F. oxysporum f.sp. erythroxyli compared with uninfected stems, antisera to the 24-kDa protein did not cross-react with any proteins from the infected coca stems. For the fungal isolates studied, the best medium tested for production of the 24-kDa protein contained 1% sucrose and 1% asparagine. Biological activity of the F. oxysporum culture filtrates on sweet basil leaves was consistently correlated with the presence of the 24-kDa protein. Production of the 24-kDa protein was limited in cultures containing pectin or cellulose as the primary carbon source, or in cultures lacking sucrose or casamino acids. Water-soluble extracts from coca stems inhibited production of the 24-kDa protein, whereas cellulose and pectin did not. Components produced by the plant may limit production of the 24-kDa protein in infected plant tissue and thereby limit the response of the plant to the fungus. These results suggest the 24-kDa protein does not function in the symptomatic phase of the F. oxysporum f.sp. erythroxylicoca disease interaction.

Culture Media↗
PubMed1996

Alpha1-adrenergic receptor subtype mRNAs are differentially regulated by alpha1-adrenergic and other hypertrophic stimuli in cardiac myocytes in culture and in vivo. Repression of alpha1B and alpha1D but induction of alpha1C.

The three cloned alpha1-adrenergic receptor (AR) subtypes, alpha1B, alpha1C, and alpha1D, can all couple to the same effector, phospholipase C, and the reason(s) for conservation of multiple subtypes remain uncertain. All three alpha1-ARs are expressed natively in cultured neonatal rat cardiac myocytes, where chronic exposure to the agonist catecholamine norepinephrine (NE) induces hypertrophic growth and gene transcription. We show here, using RNase protection, that the alpha1-AR subtype mRNAs respond in distinctly different ways during prolonged NE exposure (12 72 h). Alpha1B and alpha1D mRNA levels were repressed by NE, whereas alpha1C mRNA was induced. Changes in mRNA levels were mediated by an alpha1-AR, were not explained by altered mRNA stability, and were reflected in receptor proteins by [3H]prazosin binding. alpha1-AR-stimulated phosphoinositide hydrolysis and myocyte growth were not desensitized. Three other hypertrophic agonists in culture, endothelin-1, PGF2alpha, and phorbol 12-myristate 13-acetate, also induced alpha1C mRNA and repressed alpha1B mRNA. In myocytes from hearts with pressure overload hypertrophy, alpha1 mRNA changes were identical to those produced by NE in culture. These results provide the first example of a difference in regulation among alpha1-AR subtypes expressed natively in the same cell. Transcriptional induction of the alpha1C-AR could be a mechanism for sustained growth signaling through this receptor and is a common feature of a hypertrophic phenotype in cardiac myocytes.

Adrenergic alpha-Agonists↗
PubMed1996

Influence of the interview on the evaluation of applicants to medical school.

PURPOSE: To determine whether medical school admission interviewers change their evaluations and impressions of applicants as a direct result of the interview. METHOD: In 1991-92, 419 applicants to the University of Virginia School of Medicine were interviewed by members of the admission committee in two separate half-hour sessions. After reviewing each applicant's folder, interviewers rated the applicant before the interview on six objective scales. After the interview, ratings were again made on the same six scales, on the same form, below the ratings made before the interview. Data were examined using paired t-tests, Pearson correlations, and stepwise multiple-regression analysis. RESULTS: Of the six scales, only the ratings of Commitment to Serve Others were not significantly changed by the interview; the ratings of Familiarity with Issues in Medicine changed the most (p < .01 by paired t-test). The ratings of Overall Impression increased for accepted applicants and decreased for rejected applicants. CONCLUSION: The interview did influence interviewers' ratings made before the interview, and in the direction consistent with admission decisions, which supports the continued use of the interview. Although the magnitude of the changes was not large, the changes validate the conviction that the interview aids in the selection of individuals for medical school.

Humans↗
PubMed1994

Distribution of alpha 1C-adrenergic receptor mRNA in adult rat tissues by RNase protection assay and comparison with alpha 1B and alpha 1D.

Two alpha 1-adrenergic receptor (AR) subtypes have been defined by pharmacological studies in rat tissues, the alpha 1A and the alpha 1B, whereas three alpha 1-ARs have been cloned, alpha 1B, alpha 1C, and alpha 1D. It has been reported that alpha 1C mRNA is absent in all rat tissues, making uncertain the correspondence of this cloned subtype, if any, to the native alpha 1-ARs defined by pharmacological criteria. In the present study, a partial alpha 1C-AR cDNA was obtained from rat cardiac myocytes using RT-PCR with degenerate primers. A sensitive RNase protection assay was used to map the distribution of alpha 1C mRNA in adult rat tissues, in comparison with alpha 1B and alpha 1D. alpha 1C mRNA was abundant in heart, brain, aorta, vena cava, vas deferens, submaxillary gland, lung, and kidney; was detected at lower levels in prostate, parotid gland, and skeletal muscle; and was undetectable in liver and spleen. alpha 1B and alpha 1D mRNAs were present in most of the same tissues. In contrast to alpha 1C, however, alpha 1B and alpha 1D were both present in spleen; alpha 1B was the sole alpha 1-AR mRNA in liver; and alpha 1D mRNA was not detected in submaxillary gland, a tissue known to be enriched in the pharmacological alpha 1A. We conclude that the distribution of alpha 1C-AR mRNA in rat tissues is compatible with the idea that the alpha 1C corresponds to the classical native alpha 1A-AR. Although many tissues contain all three alpha 1-AR mRNAs, distinct tissue-specific expression is evident.

Amino Acid Sequence↗
PubMed1994

Induction of ethylene biosynthesis in Nicotiana tabacum by a Trichoderma viride xylanase is correlated to the accumulation of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase and ACC oxidase transcripts.

Xylanase (EIX) from the fungus Trichoderma viride elicits ethylene biosynthesis in leaf tissues of Nicotiana tabacum cv Xanthi but not in cv Hicks. The increase in ethylene biosynthesis is accompanied by an accumulation of 1-aminocyclopropane-1-carboxylic acid (ACC), an increase in extractable ACC synthase activity, and increases in ACC synthase and ACC oxidase transcripts. Priming of increases in ACC synthase and ACC oxidase transcripts. Priming of leaves with ethylene (120 microL/L, 14 h) sensitizes the tissue, resulting in an enhanced response to EIX and increases in both the in vivo ACC oxidase activity and ACC oxidase transcript level. EIX and ethylene independently induce ACC oxidase. Inhibition of ethylene biosynthesis by aminoethoxyvinylglycine is not accompanied by a reduction in ACC oxidase transcript level, indicating that ethylene biosynthesis is not required. In contrast to the differential induction of ethylene biosynthesis by EIX in Xanthi versus Hicks cultivars, both cultivars respond to a chemical stress (induced by CuSO4) by enhancing ethylene production. This induction is accompanied by an increase in ACC synthase transcript but not in that of ACC oxidase.

Amino Acid Oxidoreductases↗
PubMed1994

Cloning of the rat alpha 1C-adrenergic receptor from cardiac myocytes. alpha 1C, alpha 1B, and alpha 1D mRNAs are present in cardiac myocytes but not in cardiac fibroblasts.

alpha 1-Adrenergic receptor (AR) activation in cardiac muscle has several different physiological effects that might be mediated through different alpha 1-AR subtypes. Two alpha 1-AR subtypes have been cloned from the rat, the alpha 1B and the alpha 1D; both are present in adult rat heart. A third subtype, the alpha 1C, cloned from the cow and human, was reported to be absent in the rat. However, we recently found alpha 1C mRNA in adult rat heart by using a partial alpha 1C cDNA. Thus, all three cloned alpha 1-AR subtypes are present in the heart, but it is unknown whether each is expressed in cardiac myocytes or in cardiac fibroblasts. In the present study, the full-length rat alpha 1C-AR was cloned from cultured neonatal cardiac myocytes. alpha 1C mRNA transcripts of 3, 9.5, and 11 kb were present in adult rat heart by Northern blot analysis. alpha 1B-, alpha 1C-, and alpha 1D-subtype mRNAs were each present in isolated adult and neonatal cardiac myocytes by RNase protection assay. In addition, cultured neonatal cardiac myocytes expressed the three alpha 1-AR subtype mRNAs. In contrast, none of the alpha 1-AR mRNAs was detected in cultured neonatal cardiac fibroblasts. In addition, alpha 1-ARs were absent in fibroblasts by [3H]prazosin binding and norepinephrine-stimulated [3H]inositol phosphate production. The absence of alpha 1-ARs in cardiac fibroblasts differs from beta-adrenergic and angiotensin II receptors, which are present in both cardiac fibroblasts and cardiac myocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

Improved method for the routine analysis of acetylcholine release in vivo: quantitation in the presence and absence of esterase inhibitor.

An improved high-performance liquid chromatographic (HPLC) method using electrochemical detection (ED) is described capable of routinely measuring the low levels of acetylcholine (ACh) typically found in rat brain microdialysis samples. Microdialysis was performed in the striatum of the urethane anesthetized rat using a 4-mm membrane length, high recovery (40% at 1.0 microliters/min; ambient conditions), loop-design probe perfused with an artificial cerebrospinal fluid (aCSF) solution containing physiologically normal calcium levels (1.2 mM). The HPLC method utilizes a polymeric stationary phase to resolve choline (Ch) from ACh. These analytes are then converted to hydrogen peroxide (H2O2) by a solid-phase reactor (containing immobilized choline oxidase and acetylcholinesterase enzymes). The H2O2 is detected amperometrically and quantitated on a platinum (Pt) working electrode (+300 mV; with a unique analytical cell featuring a solid-state palladium reference electrode). Two designs of the Pt working electrode were examined, differing only in the support material used (Kel-F or PEEK). The Kel-F/Pt electrode had a limit of detection (LOD) for both analytes of < 30 fmol per 10 microliters with a signal-to-noise ratio of 3:1. Striatal microdialysis perfusates were monitored for ACh and Ch over a 0-1000 nM range of neostigmine (NEO) in the CSF perfusion medium. Using the 4-mm probe, basal ACh and Ch levels were detected with a NEO level as low as 10 nM and were found to be 37 +/- 3 fmol and 22 +/- 1 pmol per 10 microliters (mean +/- S.E.M., n = 6 replicates) respectively. In similar experiments using 3-mm concentric probes comparable (lower) levels of ACh were found with the 50 and 1000 nM NEO doses (n = 4-21 animals). ACh could not be reliably quantitated when animals were perfused with the 10 nM dose of NEO (n = 4). The PEEK/Pt electrode had an improved LOD of < 20 fmol per 10 microliters due to a two- to three-fold decrease in the background noise component. Basal striatal levels of ACh in the absence of NEO approached the LOD and were found to be 15 +/- 2 fmol per 10 microliters; Ch was 5 +/- 1 pmol per 10 microliters (n = 2, mean of five basal samples). The analytical system requires very little maintenance; a simple electrochemical electrode cleaning step eliminates the need for routine polishing of the Pt electrode and the mobile phase is stable for up to one week.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcholine↗
PubMed1993

Progressive feline pressure-overload: noninvasive assessment correlates with abnormalities in single cells.

Serial echocardiography and Doppler were used to monitor the progression of pressure-overload produced by banding the ascending aortas of young cats. The peak Doppler gradient across the band increased (as the animals grew in size) from 42 +/- 4.2 mmHg at 1 wk to 78 +/- 4.5 mmHg at 2-3 mos. Echocardiographic measurements of septal wall thickness increased significantly at 1 wk. Global ventricular function was unaltered in banded cats versus shams at each time point. However, in the subgroup of animals with an aortic-constricted area of < 0.025 cm2 at 1 wk, fractional shortening decreased by 40% at 2-3 mos. Contractile abnormalities were present in isolated myocytes from hypertrophied hearts. Mechanical function was more profoundly depressed in cells from hearts with echocardiographic evidence of ventricular decompensation. Echocardiographic and Doppler studies assessed cardiac size and function and identified indexes predictive of global and cellular myocardial dysfunction. The use of noninvasive techniques as a predictor of failure makes the feline model of progressive left ventricular pressure-overload useful for studies of cellular and molecular factors regulating not only the development of cardiac hypertrophy but also the transition from compensated hypertrophy to myocardial failure.

Analysis of Variance↗
PubMed1993

Sarcoplasmic reticulum-related changes in cytosolic calcium in pressure-overload-induced feline LV hypertrophy.

Alterations in Ca2+ homeostasis that involve the sarcoplasmic reticulum (SR) were studied in feline left ventricular (LV) myocytes isolated from hearts with LV hypertrophy induced by slow, progressive pressure overload. At death, severe hypertrophy was evidenced by increased heart weight-to-body weight ratio (8.4 +/- 0.6 vs. 4.2 +/- 0.2 g/kg in controls). Steady-state Ca2+ transients (measured as. indo 1 fluorescence at 410 nm/480 nm; I410/I480) in LV hypertrophy (LVH) myocytes had diminished peak amplitudes (I410/I480 2.28 +/- 0.07 vs. 2.53 +/- 0.07 in controls) and prolonged durations (0.75 +/- 0.03 vs. 0.59 +/- 0.02 s in controls). The magnitude of shortening was reduced and the contractile duration was prolonged in LVH myocytes. The idea that changes in SR function are responsible for these alterations in the Ca2+ transient was tested by studying two aspects of SR-related Ca2+ homeostasis. Restitution of releasable SR Ca2+ was studied by measuring indo 1 transients and contractions during premature beats. The time course of restitution of both the indo 1 transient and contraction of hypertrophy myocytes was significantly slower than in controls. These data suggest that restitution of releasable SR Ca2+ is slowed in hypertrophy myocytes. The reduction of the indo 1 transient and contraction in beats following long rest periods (rest decay) was measured to determine the rate of Ca2+ loss from the SR. Rest decay was significantly (P < 0.05) more pronounced in hypertrophy myocytes, suggesting that Ca2+ loss from the SR is accelerated in these myocytes. (ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Calcium transients in feline left ventricular myocytes with hypertrophy induced by slow progressive pressure overload.

A model of chronic, progressive pressure overload of the left ventricle was characterized in the cat. The aortas of young cats (10 weeks) were partially constricted with a 2.8 mm ID band, and the cats were allowed to grow to adulthood (8-13 months). This procedure resulted in severe cardiac hypertrophy as indicated by heart wt/body wt (g/kg) of 3.3 +/- 0.2 in controls (C) vs. 8.2 +/- 0.6 in left ventricular hypertrophy (LVH). The degree of aortic constriction (measured as the peak gradient across the root of the aorta) was significantly elevated in LVH 76 +/- 14 vs. -3.2 +/- 6 mmHg (C). Left ventricular systolic pressure was significantly elevated in LVH (162 +/- 18 vs. 96 +/- 7 mmHg in C). Cardiac index was significantly reduced in LVH 100 +/- 17 vs. 149 +/- 17 ml/min/kg in C, suggesting that the animals may have been progressing from a state of compensated hypertrophy to a decompensated state. The mechanical and contractile properties of isolated myocytes were also studied. LVH myocytes had significantly reduced magnitudes of shortening (6.2 +/- 0.4 vs. 7.8 +/- 0.12 %DCL), rates of shortening (0.28 +/- 0.03 vs. 0.45 +/- 0.05 %DCL/s), rates of relengthening (0.24 +/- 0.03 vs. 0.40 +/- 0.05 %DCL/s) and prolonged duration of twitch (0.67 +/- 0.04 vs. 0.55 +/- 0.03 s) compared to controls. Ca2+ transients were measured using indo-1. LVH myocytes had significantly depressed peak Ca2+ (I410/I480 2.31 +/- 0.07 vs. 2.53 +/- 0.08 in C) and significantly prolonged transient durations (0.74 +/- 0.03 vs. 0.59 +/- 0.02 s).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Correlating students' undergraduate science GPAs, their MCAT scores, and the academic caliber of their undergraduate colleges with their first-year academic performances across five classes at Dartmouth Medical School.

Reviewing the predictive validity of admission criteria to improve the selection process is important to a school in maintaining quality in the entering class. For this reason, the authors studied how the academic criteria used to select the 420 students who entered Dartmouth Medical School from 1982 to 1986 compared with the students' first-year academic performances. The criteria used were Medical College Admission Test scores, undergraduate science grade-point averages, and college selectivity (i.e., the academic caliber of the students' undergraduate colleges). Results showed that a combination of these criteria were useful in identifying the students who were successful in their first year. The authors suggest that their findings also demonstrate the ability to an admission committee to subjectively weigh these academic criteria with consistent results in student performance.

College Admission Test↗
PubMed1990

Effect of experience with nontraditional workers on psychological and social dimensions of occupational sex-role stereotyping by elementary school children.

AngloAmerican and Hispanic boys and girls ages 6 to 11 yr. (N = 219) were exposed to nontraditional workers within their elementary school classrooms. They rated 30 occupations as appropriate for men, women, or both men and women, on a pre- and posttest for a social dimension score (attribution of occupational sex-role stereotypes to others). Pre- and posttest fixed-choice selection of individual career aspirations indicated a psychological dimension score (individual job preference). Traditionality was measured from the child's point of view, not an adult concensus. Analysis shows: (a) When students are exposed to nontraditional role models their attitudes become less sex-typed on the social but not on the psychological dimension. (b) Sex and age affected career choices. (c) Historical-cultural (i.e., women's movement) events appear to have affected the children's attitudes on the social dimension.

Career Choice↗