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The experimental effect of low inference teacher clarity variables and cognitive level of questions on student achievement was determined by means of a randomized two-way analysis of variance design. Neither the main effect of cognitive level of questions on achievement nor interaction effect was significant. (Author/GK)

The purpose of the study was to determine the combined effect of six low-inference variables of teacher clarity on student achievement. Main effects for teacher clarity and for time of achievement (immediate v delayed) were significant. There was no effect of teacher clarity on student retention (Author/RD)

Research on the effects of teacher clarity on student achievement levels suggests that teacher trainees should concentrate on reducing their use of "vagueness terms" and ambiguous word phraseology in a classroom situation. (LH)

A study was done to test the effect of teacher verbal clarity on the academic achievement of college students. Teacher clarity variables included: (1) clear transition; (2) emphasis on content; (3) vagueness; and (4) additional unexplained content. Results indicate that additional research in the area is needed. (JN)

College students taught a lesson on number theory in a "clear" manner learned more than those taught in an "unclear" or imprecise manner by the same teacher. (Ed.)

Yersinia pestis, the causative agent of plague, is a highly uniform clone that diverged recently from the enteric pathogen Yersinia pseudotuberculosis. Despite their close genetic relationship, they differ radically in their pathogenicity and transmission. Here, we report the complete genomic sequence of Y. pseudotuberculosis IP32953 and its use for detailed genome comparisons with available Y. pestis sequences. Analyses of identified differences across a panel of Yersinia isolates from around the world reveal 32 Y. pestis chromosomal genes that, together with the two Y. pestis-specific plasmids, to our knowledge, represent the only new genetic material in Y. pestis acquired since the the divergence from Y. pseudotuberculosis. In contrast, 149 other pseudogenes (doubling the previous estimate) and 317 genes absent from Y. pestis were detected, indicating that as many as 13% of Y. pseudotuberculosis genes no longer function in Y. pestis. Extensive insertion sequence-mediated genome rearrangements and reductive evolution through massive gene loss, resulting in elimination and modification of preexisting gene expression pathways, appear to be more important than acquisition of genes in the evolution of Y. pestis. These results provide a sobering example of how a highly virulent epidemic clone can suddenly emerge from a less virulent, closely related progenitor. [ABSTRACT FROM AUTHOR]

The article describes a study of the effects of teacher clarity on student achievement. Indications showed that most research on the impact of teacher behavior on student learning has been correlational in design. Propositions have been made regarding the plausibility that the presence or absence of a particular teaching behavior can cause students to learn more. Researchers have attempted to respond for greater specification of teacher behavior variables and the use of experimental designs to study their effects on student achievement.

Background: Schizophreniform disorder remains poorly understood and has been reported probably to be a heterogeneous group of psychotic disorders., Method: This study compared first-episode schizophreniform disorder (N=12) and schizophrenia (N=18) patients. The authors propose that schizophreniform disorder has a different type of onset and outcome than schizophrenia. Patients were given extensive assessments at initial evaluation, 6 month follow-up, and 24 month follow-up. Comparisons between the two groups were made on type of onset, demographic, clinical ratings and outcome variables., Results: Patients with schizophreniform disorder compared to patients with schizophrenia were more likely to have an acute onset (P=0.003), and have recovered by 6 months (P=0.03). However, there were no differences in outcome at 24 months. Furthermore, all schizophreniform cases except for two were re-diagnosed at 24 months as having schizophrenia., Conclusions: The findings suggest that the initial differences of schizophreniform disorder compared to schizophrenia were not apparent at 24 months follow-up. Schizophreniform disorder did not emerge as a highly distinctive and stable form of psychosis that merits a diagnostic classification separate from schizophrenia.

A multimedia transport model was used to evaluate the environmental partitioning of benzene. Measured and predicted environmental concentrations were used to estimate the accumulation of benzene in the food chain and the subsequent extent of human exposure from inhalation and ingestion. Results show that benzene partitions mainly into air (99.9%) and that inhalation is the dominant pathway of human exposure, accounting for more than 99% of the total daily intake of benzene. Ingestion of contaminated food items represents only a minor pathway of human exposure. The long-term average daily intake of benzene by the general population of the U.S. was estimated using three independent methods. Intake estimates based on measured personal air exposures, measured exhaled air concentrations, and a pharmacokinetically derived adipose tissue concentration (73, 63, and 72 micrograms/day, respectively) are in good agreement. Although inhalation is the primary route of human exposure to background levels of benzene in the environment, smoking was found to be the largest anthropogenic source of background human exposure to benzene.

The clinical, hematologic, and cytogenetic features of ACML in children appear to be identical to Ph1-positive CML seen in adults. From our review of the literature, one could anticipate that a child with this condition would have a response to therapy and an anticipated survival similar to that seen in adults. This situation is quite different when one compares adults with ALL to children with the same disease. It has been suggested that Ph1-positive CML is an acquired, postzygotic abnormality induced by environmental agents. It is difficult to reconcile this hypothesis with the fact that this condition can be seen in infants as young as 5 months of age and the general belief that environmental carcinogens take many years to produce malignant changes in cells. Ph1-positive CML has been associated with atomic bomb exposure and it is of interest to note that two patients in the present series had received radiation. For both children and adults, bone marrow transplantation during the chronic phase is the most successful therapy if a suitable donor is available. Recently, successful marrow transplantation during the accelerated phase has also been reported. For patients without a suitable donor, control of the disease with either busulfan or hydroxyurea and attempts to induce a remission with chemotherapy during the accelerated or blast phase is the best current alternative. For patients whose blasts have lymphoid characteristics such as TdT activity, vincristine and prednisone may be successful. For those patients with a myeloid or mixed lymphoid-myeloid transformation, no chemotherapy regimen has been successful. An aggressive approach such as that described by Weinstein et al. for the treatment of acute nonlymphocytic leukemia might prove beneficial.

In anecdotal reports, problems have been cited in the health care of physicians' children, but no systematic study of this issue has been attempted. Pediatricians in a community of high physician density were interviewed to determine whether and how the health care of physicians' children differs from that of children of equivalent socioeconomic status. Of the community's 33 pediatricians, 94% responded to items in a 45-minute structured interview, for which test-retest reliability was demonstrated. Systematic differences in the care of physicians' children included delayed help seeking and increased self-referral to specialists by parents, and poor documentation of psychosocial history, less detailed instruction giving, and a reluctance to discuss problem behavior by pediatricians. Reasons cited by pediatricians for these problems included inappropriate assumptions concerning the medical knowledge of the physician's family, confusion between the roles of healer and help seeker, and embarrassment about discussing personal issues with colleagues. Pediatricians and physician parents need to become aware of and communicate about the potential for problems in the health care of physicians' children.