Surgical Outcomes Research Based on Administrative Data: Inferior or Complementary to Prospective Randomized Clinical Trials?

The importance of surgical research has gained new prominence over the past decades as the relevance of well designed and well conducted studies has become increasingly evident. There are two basic but diametrically different methods of conducting research: the prospective randomized clinical trial and the retrospective surgical outcomes study based on administrative data. Administrative databases contain data that were initially collected for purposes other than scientific research. Whereas the prospective randomized clinical trial is familiar to most surgeons, surgical outcomes research based on administrative data constitutes a genre of investigation that is often unfamiliar to and even disparaged by the surgical community. In the present article, the strengths and weaknesses of both prospective randomized clinical trials and retrospective surgical outcomes research are discussed. Specifically, the advantages and limitations of investigations based on large administrative databases are outlined. Because both study designs play an important role in surgical research, carefully designed and implemented surgical outcomes research based on administrative data should be viewed as being complementary and not inferior to prospective randomized clinical trial

A DPLL Procedure with Dichotomous Branching for Propositional Product Logic

The propositional product logic is one of the basic fuzzy logics with continuous t-norms, exploiting the multiplication t-norm on the unit interval [0,1]. Our aim is to combine well-established automated deduction (theorem proving) with fuzzy inference. As a first step, we devise a modification of the procedure of Davis, Putnam, Logemann, and Loveland (DPLL) with dichotomous branching inferring in the product logic. We prove that the procedure is refutation sound and finitely complete. As a consequence, solutions to the deduction, satisfiability, and validity problems will be proposed for the finite case. The presented results are applicable to a design of intelligent systems, exploiting some kind of multi-step fuzzy inference

IMPULSIVITY TRAITS AND THE LONGITUDINAL PREDICTION OF ADDICTIVE BEHAVIORS DURING THE TRANSITION FROM ELEMENTARY TO MIDDLE SCHOOL

The aim of this study was to test for prospective relationships between personality factors measured in elementary school and drinking, smoking, and binge eating during the first year of middle school. Data were collected among adolescents drawn from 23 elementary schools and 15 middles schools in central Kentucky. In a two-wave study, 1,906 children completed questionnaire measures in the spring of 5th grade and the spring of 6th grade. After controlling for sex, pubertal status, and prior engagement in addictive behaviors, it was found that urgency at wave 1 predicted drinking, smoking, and binge eating at wave 2, and low conscientiousness at wave 1 predicted drinking and smoking at wave 2. Risky behaviors during the first year of middle school predict subsequent life problems and subsequent diagnosable addictive disorders. The finding that those behaviors can be predicted by personality factors measured in elementary school indicates the value, for risk researchers and prevention specialists, of focusing efforts on children prior to the onset of adolescence

Functions of Code-switching in EFL Classrooms with Native and Non-native Speaker Teachers: A Qualitative Study in A Turkish University

This study aimed to find out how code switching functions in EFL classes with native (NS) and non-native speaker (NNS) teachers by using classroom observation and interview methods. To reach this aim 162 B-level students and 8 teachers were observed for 16 audio- recorded classroom hours in the School of Foreign Languages Department of a private university. In addition, semi-structured interviews were carried out with all of the 8 teachers who participated in the research and 37 students in groups of 4 to 7 from each of the observed classes. NVivo technique was employed to categorise and store the data. The seven functions (themes) which emerged from the utterances made during the interviews and the classroom talks were; ‘motivating, activating and drawing attention’, ‘comprehending’, ‘feeling free while expressing meaning’, ‘cultural orientation’, ‘naturality’, ‘negotiation’, and ‘feeling secure and relaxed’. Results indicated that there were not many noteworthy differences between the functions of code switching used by NS and NNS teachers. Both the NS and NNS teachers switched to the students’ first language for purposes such as helping them comprehend, feel secure and relaxed, motivating and activating them, drawing their attention, and for orienting to their culture. On the other hand, the students’ switching to L1 served comprehending, feeling free while expressing meaning, getting motivated and activated, feeling secure and relaxed, cultural orientation, naturality and negotiating with the teacher. Both NS and NNS teachers let the students switch to L1 but their second turns following the students’ first turns in L1 were observed to be always in L2. It was concluded that students’ switching to L1 for functions such as naturality and negotiating which occurred both in the NNS and NS teachers’ classes might involve some kind of resistance to using a foreign language, thereby hindering target language learning, whereas other functions of code switching might promote it

INTERNALIZING AND EXTERNALIZING DYSFUNCTION: AN INTEGRATIVE MODEL OF ADOLESCENT DRINKING

Separate externalizing and internalizing pathways to problem drinking have been described. However, internalizing and externalizing are substantially correlated, thus, there is good reason to believe that these two forms of dysfunction behaviors do not operate independently. We tested an integrative developmental model of transactions among internalizing symptomatology, externalizing personality, and psychosocial learning in the prediction of both drinking problems and future internalizing symptoms. To do so, we studied a large sample (n = 1910, 49.9% female) of children over a critical developmental period, from the spring of 5th (last year elementary school) grade through the spring of 9th grade (first year of high school). Using a battery of self-report questionnaires, we assessed demographics, pubertal status, negative urgency, depressive symptoms, positive drinking expectancies, and drinking behavior. Specifically, the present study tested whether internalizing symptomatology (depressive symptoms) in elementary school predicts a classic externalizing pathway ( to problem drinking in middle school, and whether problem drinking in middle school predicts increased depressive symptomatology in highschool. Structural equation modeling yielded significant findings for hypothesized direct and indirect pathways, with overall good model fit (CFI = .94; SRMR = .05; RMSEA = .05, 90% CI .04-.05): elementary school depressive symptomatology predicted middle school drinking problems (mediated by negative urgency and psychosocial learning) and middle school drinking problems predicted increased risk for depressive symptoms in high school, pointing to a reciprocal relationship between internalizing and externalizing dysfunction. The present study incorporated internalizing symptomatology into a traditional externalizing model of drinking risk, and demonstrated a reciprocal relationship between internalizing and externalizing dysfunction during adolescence. These findings are particularly noteworthy when considered in a developmental framework. The present study highlights the need to integrate both internalizing and externalizing forms of dysfunction into models of substance use risk

Sample Size Matters: A Guide for Surgeons

Considerations of sample size computations in the medical literature have gained increasing importance over the past decade and are now often mandatory for scientific grant proposals, protocols, and publications. However, many surgeons are ill-prepared to understand the parameters on which the appropriate sample size is based. The present article has several objectives: first, to review the need for sample size considerations; second, to explain the ingredients necessary for sample size computations in simple, nonmathematic language; third, to provide options for reducing the sample size if it seems impracticably large; and fourth, to help avoid some of the more common mistakes encountered when computing sample size