Children's concurrent use of rehearsal and organizational strategies.

This study examined whether children could benefit from the simultaneous use of two mnemonic strategies. In Experiment 1, 3rd and 6th graders were taught to use the rehearsal and organizational strategies of same- or different-aged peers. At both ages, Ss who used developmentally advanced techniques recalled more than those who sorted and rehearsed like younger children; moreover, use of both efficient strategies together increased recall additively. In Experiment 2, 3rd graders rehearsed in any way they wished while learning taxonomically related or unrelated items. With each type of materials, 4 groups differed in whether the items were left visible, in whether Ss were asked to sort, and, if so, in whether they were instructed to sort to "help them remember" or on the basis of meaning. Those Ss instructed to sort showed higher recall and more active rehearsal, regardless of type of sort instructions or items. Thus, the use of one strategy may elicit effective use of another. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spliceosome Mutations in Uveal Melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy of the eye. It has a high metastatic potential and mainly spreads to the liver. Genetics play a vital role in tumor classification and prognostication of UM metastatic disease. One of the driver genes mutated in metastasized UM is subunit 1 of splicing factor 3b (SF3B1), a component of the spliceosome complex. Recurrent mutations in components of the spliceosome complex are observed in UM and other malignancies, suggesting an important role in tumorigenesis. SF3B1 is the most common mutated spliceosome gene and in UM it is associated with late-onset metastasis. This review summarizes the genetic and epigenetic insights of spliceosome mutations in UM. They form a distinct subgroup of UM and have similarities with other spliceosome mutated malignancies.     

Developmental differences in the memory search of categorized lists.

16 right-handed female 3rd and 6th graders were tested in a recognition memory task with short lists of items from 1 or 2 categories. Latency data for 1-category lists of letters or digits were consistent with a serial-exhaustive model of memory search for both groups. It was also found that the younger Ss searched these lists more slowly. For 2-category lists, developmental differences were found in Ss' ability to use the category information to facilitate information retrieval. Although the category information was very salient for Ss of both ages, only the 6th graders were able to use it to modify their memory search. It was noted that the 6th graders' 2-category data were consistent with a particular nonexhaustive search strategy, the random entry model, which has previously been identified by M. J. Naus et al (see record 1973-06031-001) for adult Ss. The similarity of the 3rd graders' memory search for 1- and 2-category lists suggests that young children do not systematically use information that they have available in permanent memory to facilitate their performance in memory search. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Degradation assessment of structures and passive components at nuclear power plants

This paper describes a multi-year research program to assess age-related degradation of structures and passive components important to the safe operation of nuclear power plants (NPPs). The purpose of the research effort is to develop the technical basis for the validation and improvement of analytical methods and acceptance criteria which can be used to make risk-informed decisions and to address technical issues related to degradation of structures and passive components. The approach adopted for this research program consists of two phases. In Phase I, specific degradation occurrences at plants were collected and evaluated, existing technical information on aging was reviewed, and a scoping study was performed to identify which structures and components should be studied in the subsequent phases of the research program. Based on the results of the Phase I effort, selected structures and passive components are evaluated in Phase II to assess the effects of age-related degradation using existing and enhanced analytical methods. Fragility analyses are performed for undegraded and degraded structures and passive components. These results can then be used to assess the potential impact of degradation on overall plant risk. The Phase II effort also utilizes the results of the analyses to develop probabilistic degradation acceptance criteria for the structures and passive components studied. These research activities provide useful tools to support the current goals of developing risk-informed and performance-based regulation in the nuclear industry.     

Progress report

RILEM Technical CommitteesRILEM TC 160-MLN: Methodology for Life Prediction of Concrete Structures in Nuclear Power Plants

Progress report August 1999     

Power Comparison of Two Tests of Non-Random Clustering

This paper presents two definitions of maximum cluster, that have sometimes been used to test for non-random clustering. We compare the power of the testa based on these statistics, and show that when the clustering interval is sufficiently small, one of the tests is more powerful for a wide class of alternative hypotheses. We show that this test is the generalized likelihood ratio test for an alternative hypothesis related to a particular type of non-random clustering.     

Visible absorption bands of the (O2)2 collision complex at pressures below 760 Torr

The collision-induced absorption of oxygen in the 540-650-nm wavelength region has been measured ata pressure range from 0 to 730 Torr at T 5 294 K. Pressure-dependent cross sections of the X 3Sigmag(+)+X 3Sigmag alpha 1Deltag(nu =0) + alpha 1Deltag(nu = 1 ) and X 3Simag(+)+ X 3Sigmag+--> alpha 1Deltag(nu =0) + 1 alpha 1Deltag (nu = 0) transitions have been determined by means of cavity-ringdown spectroscopy. Contributions of the overlapping g and d bands of O2 have been evaded, and Rayleigh extinction has been taken into account.     

Effects of graft-derived dopaminergic innervation on the target neurons of patch and matrix compartments of the striatum

Fetal dopaminergic neurons grafted into the dopamine-depleted striatum have previously been shown to normalize neurochemical and behavioural abnormalities. However, the extent of graft-induced recovery of striatal compartments, which differ in their ontogeny, neurochemical properties and function, is still not clear. The striosome and matrix compartments of the striatum provide a segregated projection to somatostatin-containing GABAergic neurons of the rostral part of the entopeduncular nucleus and somatostatin-negative GABAergic neurons of the caudal part of the entopeduncular nucleus, respectively. In the present study, preprosomatostatin and glutamate decarboxylase messenger RNA levels in the rostral and caudal parts of the entopeduncular nucleus were determined six and 18 months postgrafting in rats with complete recovery of rotational behaviour following apomorphine challenge, and in rats with unilateral 6-hydroxydopamine lesions or sham lesions and no grafts. Sections were processed for in situ hybridization using 35S-labelled cRNA probes for glutamate decarboxylase (67,000 mol. wt isoform; GAD67) and preprosomatostatin. Autoradiographs showed a marked increase in preprosomatostatin messenger RNA within the ipsilateral entopeduncular nucleus in 6-hydroxydopamine-lesioned rats, and a substantially lower increase six months postgrafting. At 18 months postgrafting, the preprosomatostatin messenger RNA levels were symmetrical within the entopeduncular nucleus. Unilateral depletion of striatal dopamine resulted in a moderate increase in GAD67 messenger RNA levels within the ipsilateral entopeduncular nucleus, along with a substantial decrease in GAD67 levels within the contralateral nucleus. By six months postgrafting, the GAD67 levels had decreased considerably within the ipsilateral entopeduncular nucleus, while the messenger RNA levels had returned to normal within the contralateral nucleus. Interestingly, at 18 months postgrafting, the GAD67 levels remained decreased within the ipsilateral entopeduncular nucleus and were significantly lower than the normal value. The results indicate that fetal nigral grafts placed within the dopamine-depleted striatum can restore the neurochemical alterations seen in striatal target areas such as the entopeduncular nucleus. This may form the neurochemical basis of graft-induced behavioural recovery, as the normalization of neurotransmitter messenger RNA levels in the entopeduncular nucleus reflects the restoration of overall activity in both direct and indirect striatal output pathways. The results also indicate that the graft-derived dopaminergic innervation restores the output of both striosome and matrix compartments of the striatum. The present results also showed a progressive recovery leading to over-compensation of neurotransmitter messenger RNA levels following grafting, perhaps indicating the importance of feedback regulation of grafted dopaminergic neurons by the host.     

Tuberculosis surveillance practices in long-term care institutions

OBJECTIVES: To identify the tuberculosis (TB) skin-testing practices of long-term care facilities for the elderly in Toronto, Ontario. DESIGN: A telephone survey using a 25-item questionnaire. SETTING: Twenty-nine nursing homes (NHs) and 26 Homes for the Aged (HFAs) in metropolitan Toronto. RESULTS: Thirty-one percent of facilities (17 of 55) had no formal tuberculin skin-testing program, including 52% of NHs (15 of 29) versus 8% of HFAs (2 of 26; P = 0.001). Ninety-two percent of HFAs (24 of 26), compared with 45% of NHs (13 of 29), obtained preadmission or admission skin-test status of residents (P = 0.0005). Annual testing was performed at 46% of HFAs (12 of 26) and 27% of NHs (8 of 29; P = 0.28). Of facilities that carried out any skin testing, 64% of HFAs (16 of 25) versus 32% of NHs (6 of 19) measured induration to establish test positivity (P = 0.068). Fifty-two percent of HFAs (13 of 25), compared with 21% of NHs (4 of 19), recorded the actual size of induration in the patient record (P = 0.085). Only 28% of HFAs (7 of 25) and 21% of NHs (4 of 19) correctly defined a positive tuberculin skin test. CONCLUSIONS: TB surveillance practices in long-term care institutions in Toronto are inadequate and often yield results that do not predict the risk of infection and cannot be used to investigate outbreaks. Tuberculin skin-testing practices were better at HFAs, which are subject to provincial legislation regarding TB surveillance, than at NHs, which are not subject to this legislation. Staff at HFAs and NHs require education regarding tuberculin skin-testing policies and procedures.