Zippy Erlich

Depression and suicidal behavior in adolescent inpatients with obsessive compulsive disorder

BACKGROUND To investigate the prevalence and correlations of suicidal behavior in obsessive compulsive disorder (OCD) among adolescent psychiatric inpatients. METHODS A total of 348 adolescents, representing consecutive admissions to an adolescent inpatient unit, were assessed. Of these, 40 patients had OCD, 118 had schizophrenia, 59 had an affective disorder, 81 had a conduct disorder and 50 had an eating disorder. In addition, 87 normal community controls were assessed. All subjects were assessed for suicidal behavior by the Childhood Suicide Potential Scale (CSPS), for depression by the Beck Depression Inventory, for impulsiveness by the Impulse Control Scale, for anxiety by the State-Trait Anxiety Scale and for aggression by the Yudowsky Overt Aggression Scale. RESULTS All the psychiatrically ill subjects, including those with OCD, had high levels of depression, anxiety and impulsiveness, which were far higher than those of the controls. The rate of attempted suicide was, however, much lower in the OCD subjects. In addition, there was a significant inverse correlation between suicidal behavior levels on the CSPS and depression in the OCD subjects, while all other subjects showed the expected significant positive correlation between level of suicidal behavior and depression. LIMITATIONS This study looked at a referred population and generalization to outpatient and community samples cannot be made. Distinguishing between the primary and the comorbid diagnosis is difficult and some findings are based on small sample size and therefore may be vulnerable to type I error. CONCLUSIONS Although suicidal ideation and depressive symptoms are common in OCD adolescent inpatients, they seem to be protected against suicide attempts. The inverse relationship between suicidal behavior and depression may mean that suicidal behavior is, in some ways, qualitatively different from that seen in other psychiatrically ill adolescents.

Computer literacy and application via distance e-learning

Abstract In this paper we present an innovative framework for the teaching of computer literacy and application that can serve as a new educational paradigm in teaching courses in a distance learning format. This new framework combines and integrates new technologies with older distance education teaching aids. We implement this framework in a course called “Computer Applications for Social Sciences” that was developed in the Open University of Israel, a recognized academic institution in Israel. The course, which is based on distance learning and electronic tools such as communication technologies, CD-ROM coursewares, Web-sites and discussion groups, was taught in the second semester of 1999. The course was developed in a way that allows students with no previous knowledge to learn it at a distance. We present here a description of the course and its e-learning tools, a broad study on the 219 students who participated in the course, and a close study on 55 of these students.

Data Mining by Means of Binary Representation: A Model for Similarity and Clustering

In this paper we outline a new method for clustering that is based on a binary representation of data records. The binary database relates each entity to all possible attribute values (domain) that entity may assume. The resulting binary matrix allows for similarity and clustering calculation by using the positive (‘1’ bits) of the entity vector. We formulate two indexes: Pair Similarity Index (PSI) to measure similarity between two entities and Group Similarity Index (GSI) to measure similarity within a group of entities. A threshold factor for each attribute domain is defined that is dependent on the domain but independent of the number of entities in the group. The similarity measure provides simplicity of storage and efficiency of calculation. A comparison of our similarity index to other indexes is made. Experiments with sample data indicate a 48% improvement of group similarity over standard methods pointing to the potential and merit of the binary approach to clustering and data mining.

Cohesion and roles: network analysis of CSCL communities

We provide empirical support for the assertions that high level of knowledge construction is associated with structured design and that knowledge construction is associated with cohesion and equivalence network structures. We built and analyzed two CSCL communities - one structured the other nonstructured. The levels of learning processes were measured by content analysis. The social capital structure of the communities was analyzed by social network analysis. The analysis revealed that the structured community developed social capital, encoded by a mesh of interlinked cliques, and that participants undertook bridging and triggering roles, and exhibited high levels of constructing knowledge. The tutor (guide) remained on the side. The nonstructured community did not construct knowledge, cohesion was dull, and participants did not undertake any essential roles.

Differentiation between right tubo-ovarian abscess and appendicitis using CT—A diagnostic challenge

AIM To determine CT features that can potentially differentiate right tubo-ovarian abscess (TOA) from acute appendicitis (AA; including abscess formation). MATERIALS AND METHODS The abdominal computed tomography (CT) images of 48 patients with right-sided TOA (average age 39.3 ± 9.8 years) and 80 patients (average age 53.5 ± 19.9 years) with AA (24 with peri-appendicular abscess) were retrospectively evaluated. Two experienced radiologists evaluated 12 CT signs (including enlarged, thickened wall ovary, appendix diameter and wall thickness, peri-appendicular fluid collection, adjacent bowel wall thickening, fat stranding, free fluid, and extraluminal gas) in consensus to categorize the studies as either TOA or AA. The diagnosis and the frequency of each of the signs were correlated with the surgical and clinical outcome. RESULTS Reviewers classified 92% cases correctly (TOA=85%, AA=96.3%), 3% incorrectly (TOA=6.3%, AA=1.3%); 5% were equivocal (TOA=8.3%, AA=2.5%). In the peri-appendicular abscess group reviewers were correct in 100%. Frequent findings in the TOA group were an abnormal ovary (87.5%), peri-ovarian fat stranding (58.3%), and recto-sigmoid wall thickening (37.5%). An abnormal appendix was observed in 2% of TOA patients. Frequent findings in the AA group were a thickened wall (32.5%) and distended (80%) appendix. Recto-sigmoid wall thickening was less frequent in AA (12.5%). The appendix was not identified in 45.8% of the TOA patients compared to 15% AA. CONCLUSIONS In the presence of a right lower quadrant inflammatory mass, peri-ovarian fat stranding, thickened recto-sigmoid wall, and a normal appearing caecum, in young patients favour the diagnosis of TOA. An unidentified appendix does not contribute to the differentiation between TOA and peri-appendicular abscess.

Mechanisms and architectures of online learning communities

Online communities are described in terms of collections of virtual neighborhoods, each of which is a subset of interdependent members. The significant virtual neighborhoods are revealed by fitting parametric Markov field models (p*) to the response relations of the communities. The underlying theoretical mechanisms are then deduced by matching the revealed virtual neighborhoods with the predictions of network emergence theories. We demonstrate that the underlying mechanisms are related to specific design features of the communities. This method can be extended to other relations in online communities and to longitudinal analysis, and applied to real-time monitoring of online communications.

Pointers and data abstractions in high level languages-I: Language proposals

Recognizing the problems that the use of pointers pose to the construction of reliable software, this two-part paper proposes a scheme by which pointers may be used in a controlled manner to build data abstractions without being used as abstractions in their own right. Part I presents the language constructs facilitating the proposal. Part II (to be published in a forth-coming issue) attempts to show, by use of a fairly complex example, that proving the correctness of an implementation of an abstraction built in this manner from pointers need not be more difficult than other implementation correctness proofs.