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At least 73 records · Page 4Linked to original sources
PubMed1978

Unprofessional physicians--some correlative data.

In the background of those physicians who have problems in medical practice serious enough to attract attention by the licensing body, there are factors that apparently can help predict such behavior. As a candidate for medical school the applicant more likely to have future problems has the following profile: (1) older than the average applicant with a lower grade point average; (2) more likely to have used tobacco; (3) did not receive a baccalaureate degree; (4) no military service; (5) turned in a sloppy handwritten application form, and (6) received a less than ideal character reference by the college from which applying. Furthermore, after admission to medical school the person more prone to future problems tends to be a poorer student than his peers and to receive a poorer rating in his first postgraduate year. The Loma Linda University graduate who has had such problems is also more likely to have settled in Southern California and to be in general practice.

Achievement↗
PubMed2006

Structured correlation in models for clustered data.

Correlation is always a concern in the analysis of clustered data. One area of interest is to develop a general correlation modelling approach for high dimensional data with unbalanced hierarchical and heterogeneous data structures, e.g. multilevel data. Commonly used correlation structures might have limitation for such situations. In this paper, we propose two extensions, multiblock and multilayer correlations. These methods are very flexible in modelling correlation and can be incorporated in many multivariate approaches, while the major discussion focuses on the applications under the generalized estimating equations (GEE) methods. The approaches are especially useful in GEE when each cluster is large and complex but the number of clusters is small. If an incorrect correlation is applied to such data, the results are less efficient. Multiblock and multilayer correlations extend GEE methods to model complicated multilevel data with arbitrary number of levels and cluster size. The extended estimating equation for correlation parameters has an orthogonal property, and the computation is very efficient. A simulation study compares the conventional methods versus the proposed methods, and it shows the gain in relative efficiency and the flexibility in modelling various structures.

Adult↗
PubMed2002

The learning and application of generic skills by CLSs/MTs who have 'left the field'.

OBJECTIVE: To determine whether generic skills that dinical laboratory scientists (CLSs)/medical technologists (MTs) learned as students and/or practitioners are applied to jobs outside the field of CLS/MT; and to determine if there are any significant differences in learning and/or doing these skills by CLS/MT majors vs. non-CLS/MT majors. DESIGN: An Occupational Change Survey was sent to CLS/MT practitioners who had identified themselves as having left the field (LTF) of CLS/MT. The participants were asked whether or not they were CLS/MT majors as undergraduates, whether they utilized generic baccalaureate level skills in their LTF jobs, and whether or not they learned these skills as CLS/MT students and/or practitioners. The skills were: problem solving, decision making, troubleshooting, analytical reasoning, data correlation, precision studies, quality assessment, teaching, research, communication, technical writing, computer use, utilization review, and supervision. SETTINGS AND PARTICIPANTS: The survey was sent to 105 participants of an ongoing longitudinal study who identified themselves as having LTF. MAIN OUTCOME MEASURES: Responses for doing/utilizing the skills were grouped as 'Yes' if participants indicated they frequently or sometimes used the skills in their LTF jobs, and 'No' if they indicated they rarely or never used the skills in their LTF jobs. Responses for learning the skills were grouped as 'Yes' if participant indicated they learned the skills as CLS/MT students, practitioners or both and 'No' if they indicated they never learned the skills as CLS/MT students, practitioners, or both. Participants indicated whether or not they were CLS/MT majors in college. Chi square analyses were performed to test for any statistical significant (p = 0.05) differences between: doing and learning the skills, doing the skills and being a CLS/MT major, and learning the skills and being a CLS/MT major. RESULTS: The response rate for the survey was 48% (50/103). Chi square analyses could not be performed for doing the skills in the LTF jobs for three variables: problem solving, analytical reasoning, and computer use because all respondents reported that they used these skills. Chi square analyses indicated there were no significant differences between doing and learning the skills in the LTF job for the entire sample group for all remaining skills except supervision. There were no significant differences between doing the skills in the LTF job and being a CLS/MT major. A statistically significant difference in learning the skills was observed between CLS/MT majors and non-CLS/MT majors for the following skills: problem solving, correlating data, precision studies, research, analytical reasoning, and troubleshooting. The 'Yes' answer frequencies for learning the skills was higher for the CLS/ MT majors for all the generic skills except teaching, where they were equal, and utilization studies where they were lower. CONCLUSION: The results indicate that, in general, for this sample group, generic skills learned as CLS/MT students and/or practitioners can be and are applied to a wide variety of LTF jobs. Furthermore, CLS/MT majors learned the generic skills at least as well, if not better, than other baccalaureate level laboratory practitioners who obtained degrees in other areas.

Career Choice↗
PubMed2000

Bayesian predictive inference for time series count data.

Correlated count data arise often in practice, especially in repeated measures situations or instances in which observations are collected over time. In this paper, we consider a parametric model for a time series of counts by constructing a likelihood-based version of a model similar to that of Zeger (1988, Biometrika 75, 621-629). The model has the advantage of incorporating both overdispersion and autocorrelation. We consider a Bayesian approach and propose a class of informative prior distributions for the model parameters that are useful for prediction. The prior specification is motivated from the notion of the existence of data from similar previous studies, called historical data, which is then quantified into a prior distribution for the current study. We derive the Bayesian predictive distribution and use a Bayesian criterion, called the predictive L measure, for assessing the predictions for a given time series model. The distribution of the predictive L measure is also derived, which will enable us to compare the predictive ability for each model under consideration. Our methodology is motivated by a real data set involving yearly pollen counts, which is examined in some detail.

Bayes Theorem↗
PubMedDate not supplied

[Structure-physiological activity correlation for picolinic acid derivatives based on quantum chemical data].

Correlation between structure and properties for picolinic acid derivatives with and without bimodal effect was evaluated by quantum chemical calculations. Comparative data obtained by SCF MO method in the 3-21G/6-31G* basis indicate lower ionization potential in picolinic acid derivatives with bimodal effect as compared to those lacking this effect. This validates our previous assumption that physiological bimodal effect is defined by the electron structure of the molecules. Quantum chemical calculations allowed us to predict bimodal physiological activity in amino-substituted derivatives of picolinic acid.

Molecular Structure↗
PubMed2005

Exact tests for one sample correlated binary data.

In this paper we developed exact tests for one sample correlated binary data whose cluster sizes are at most two. Although significant progress has been made in the development and implementation of the exact tests for uncorrelated data, exact tests for correlated data are rare. Lack of a tractable likelihood function has made it difficult to develop exact tests for correlated binary data. However, when cluster sizes of binary data are at most two, only three parameters are needed to characterize the problem. One parameter is fixed under the null hypothesis, while the other two parameters can be removed by both conditional and unconditional approaches, respectively, to construct exact tests. We compared the exact and asymptotic p-values in several cases. The proposed method is applied to real-life data.

Anti-Bacterial Agents↗
PubMedDate not supplied

On correlations between adjacent velocities and accelerations in longitudinal growth data.

Correlations are examined between adjacent velocity and acceleration growth in stature, weight and skinfold thickness in a group of adolescent boys measured approximately quarterly. It is concluded that some substantial component of the variability behaves rather like measurement error, and this is likely to represent negative feedback homeostasis.

Acceleration↗
PubMed1996

Factors affecting performance of PACS.

We experimentally constructed a personal-computer-based Picture Archiving and Communication System (PACS) for color images of dermatology clinics. This system should especially satisfy such a demand as to be able to retrieve an image within a few seconds from the database residing in a remote server. Our two objectives in the experiment were: To examine how much time was consumed in each part of PACS while it does a series of jobs, from the requesting of an image to its display on the screen of the workstation of the user. The other objective was to see if a personal-computer-based PACS could satisfy our criteria. Total retrieving time, data reading time, data transporting time and image displaying time were measured. Total retrieving time can be divided into three procedures: Data reading time, data transporting time, image displaying time. Data reading time was about 0.6 second for reading an image with the size of 1 mega bytes (MB). Data reading time and the size of data were linearly correlated. Data transporting time was about 11 seconds for transporting an image with the size of 1 MB through EtherTalk, and 66 seconds through LocalTalk. Data transporting time and the size of the data were also linearly correlated. Data reading time and data transporting time was able to be reduced largely by compression technique. However, smaller data give other important effects to the network system besides reducing the time of data reading, data transporting and data displaying. Most Local Area using image Network (LAN) systems, such as EtherTalk, adopt Carrier Sense Multiple Access with Collision Detection (CSMA/CD) for the way of accessing to other computer. In CSMA/CD, transporting performance suddenly declines if the congestion of signal in a network gets beyond a critical level. This situation fatally impairs the performance of a network. We concluded that data compression plays an important role to improve the performances of PACS, especially those of a server and the network system. A personal-computer-based PACS with EtherTalk and an image compression/decompression hardware, e.g., CL550A chip, satisfies our criteria.

Dermatology↗