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Biomedical subjects

M Bruck

Publications and source records attributed to M Bruck.

At least 37 records · Page 2Linked to original sources

Phonological awareness in young second language learners.

English-speaking children (N = 91) who were attending French schools (bilingual group) were given a battery of phonological awareness tests in kindergarten and in grade I. At the time of kindergarten testing the mean age of the children was 5:9. Their performance was compared to age-matched English-speaking children (N = 72) attending English schools (monolingual group). The bilingual children showed heightened levels of phonological awareness skills in kindergarten in the area of onset-rime awareness. By grade I, the pattern of group differences was more complex. The monolingual and bilingual children performed similarly on onset-rime segmentation tasks. The monolingual children had higher phoneme awareness scores than their French-schooled peers; this result is interpreted to reflect the role of literacy instruction on phoneme awareness development. In comparison, the bilingual children had higher syllable segmentation scores than their monolingual peers. This result is interperted to reflect the role of second language input on phonological awareness.

Awareness↗

Role of the syllable in the processing of spoken English: evidence from a nonword comparison task.

Previous research using monitoring tasks suggests that syllables do not play a role in the initial processing of speech by English listeners. The role of syllables in a different task, one involving the speeded comparison of 2 nonwords, was investigated. In 2 experiments, responses to nonword pairs that shared a complete syllable were significantly faster than responses to pairs that shared part of a syllable when the shared unit was at the beginning or in the middle of the nonwords. Results were mixed when the shared unit was at the end of the nonwords, possibly reflecting a confounding effect of rhyme. Findings suggest that syllabified representations of the nonwords may be used in a comparison task, even in English. Results are interpreted relative to different demands of the nonword comparison and monitoring tasks.

Adult↗

"I hardly cried when I got my shot!" Influencing children's reports about a visit to their pediatrician.

We examined, in 2 phases, the influence of postevent suggestions on children's reports of their visits to a pediatrician. Phase 1 examined the effect of giving one of 3 types of feedback to 5-year-old children immediately following their Diphtheria Pertussis Tetanus (DPT) inoculation. Children were given pain-affirming feedback (the shot hurt), pain-denying feedback (the shot did not hurt), or neutral feedback (the shot is over). 1 week later, they did not differ in their reports concerning how much the shot hurt or how much they cried. In Phase 2, the same children were visited approximately 1 year after their inoculation. During 3 separate visits, they were either given additional pain-denying or neutral feedback. They were also given misleading or nonmisleading information about the actions of the pediatrician and the assistant. Children given pain-denying feedback reported that they cried less and that the shot hurt less than did children given neutral feedback. Those who were given misleading information about the actions of the assistant and the pediatrician made more false allegations about their actions than did children who were not given this information. These results challenge the view that suggestibility effects are confined to peripheral, nonaction events; in this study children's reports about salient actions involving their own bodies in stressful conditions were influenced.

Child↗

Drug-metabolizing enzyme activities in freshly isolated oval cells and in an established oval cell line from carcinogen-fed rats.

The activities of several different phase I and phase II drug-metabolizing enzymes were measured in freshly isolated oval cells from rats fed a choline-deficient/DL-ethionine-supplemented diet for 6 weeks and also in vitro in the established oval cell line OC/CDE 6. No cytochrome P450 was spectrophotometrically measurable in both preparations and two cytochrome P450-dependent monoxygenase activities, aminopyrine N-demethylase and ethoxyresorufin O-deethylase, could not be detected in the oval cells of both sources. However, cytosolic glutathione transferase, microsomal epoxide hydrolase and UDP-glucuronosyltransferase activities were clearly measurable in oval cells. Similar enzyme activities were found in freshly isolated and cultured oval cells. The highest activities of these three enzymes were detected during the exponential growth phase of the cultured cells; thereafter the activities decreased until the cells reached confluency. Changes in phenol UDP-glucuronosyltransferase (UGT1A1) mRNA levels paralleled the variations in UDP-glucuronosyltransferase activity, i.e. they were high in exponentially growing oval cells and low in confluent cell cultures. Taking into account that oval cells are able to proliferate in the livers of rats continuously fed a choline-deficient/DL-ethionine-supplemented diet and that none of the analyzed drug metabolizing enzymes are involved in the activation or detoxication of DL-ethionine, the described pattern might be part of a more general, nonspecific, protection mechanism enabling these cells to overcome the cytotoxic effects of a variety of carcinogens and to proliferate even in their presence. Furthermore, the expression of microsomal epoxide hydrolase, cytosolic glutathione transferase and UDP-glucuronosyltransferase appears to depend on the proliferative status of the cells.

Animals↗

The possible role of source misattributions in the creation of false beliefs among preschoolers.

In this article the authors examine one possible factor in the creation of false beliefs among preschool-aged children, namely, source misattributions. The authors present the results from an ongoing program of research which suggest that source misattributions could be a mechanism underlying children's false beliefs about having experienced fictitious events. Findings from this program of research indicate that, although all children are susceptible to making source misattributions, very young children may be disproportionately vulnerable to these kinds of errors. This vulnerability leads younger preschoolers, on occasion, to claim that they remember actually experiencing events that they only thought about or were suggested by others. These results are discussed in the context of the ongoing debate over the veracity and durability of delayed reports of early memories, repressed memories, dissociative states, and the validity risks posed by therapeutic techniques that entail repeated visually guided imagery inductions.

Child, Preschool↗

[Pharmacology and clinical drug research in 18th-century Vienna].

"The history of medication and early clinical pharmacological research in Vienna in the 18th century" is starting on a broad summary of nearly two millenniums of medical therapy and "materia medica". Commencing with the antique hippocratic school and progressing in a rapid overview of the most important and commonly known facts on medication and therapy, this contribution leads into a more extensive investigation trying to emphasize the importance of the so-called "First Viennese Medical School" and the scientific works of two Viennese medical doctors originated from Luxemburg, H. J. Crantz and H. J. Collin, in the investigation and propagation of new remedies and the progress of therapy.

Austria↗

Suggestibility of the child witness: a historical review and synthesis.

The field of children's testimony is in turmoil, but a resolution to seemingly intractable debates now appears attainable. In this review, we place the current disagreement in historical context and describe psychological and legal views of child witnesses held by scholars since the turn of the 20th century. Although there has been consistent interest in children's suggestibility over the past century, the past 15 years have been the most active in terms of the number of published studies and novel theorizing about the causal mechanisms that underpin the observed findings. A synthesis of this research posits three "families" of factors--cognitive, social, and biological--that must be considered if one is to understand seemingly contradictory interpretations of the findings. We conclude that there are reliable age differences in suggestibility but that even very young children are capable of recalling much that is forensically relevant. Findings are discussed in terms of the role of expert witnesses.

Adult↗

Glutathione depletion in chronic lymphocytic leukemia B lymphocytes.

Glutathione (GSH) content may be the major determinant of a cell's sensitivity to cytotoxic alkylating agents. In the present study, the GSH concentration was determined in lymphocytes isolated from the blood of normal subjects and patients with chronic lymphocytic leukemia (CLL). Comparable levels were found in both types of cells. Incubation for 20 hours led to a decrease in GSH to 51% of baseline values in CLL B cells. Under the same conditions, normal B- or T-lymphocyte GSH content remained constant. GSH depletion was shown to be a characteristic of the B-CLL B lymphocyte. It was not found in the T cells of patients with B-CLL or in cells from patients with T-CLL. Chlorambucil (CLB) contributes to the decrease in GSH in B-CLL lymphocytes; after incubation with the drug, lower levels of GSH were found than in the normal B or T lymphocytes, B-CLL T cells, or T-CLL (CD4 or CD8) cells. GSH depletion of CLL B lymphocytes may be related to the greater therapeutic efficacy of CLB in B-CLL than in T-CLL.

B-Lymphocytes↗

The absolute configuration of an intermediate in the asymmetric synthesis of unusual amino acids.

(4R)-3-[(2'R,3'R)-2'-Bromo-3'-(phenylbutanoyl)]-4-(phenylmethyl)-2 - oxazolidinone, C20H20Br-NO3, M(r) = 402.30, monoclinic, P2(1), a = 11.542 (2), b = 7.625 (1), c = 11.667 (1) A, beta = 113.97 (1) degrees, V = 938.2 (2) A3, Z = 2, Dx = 1.42 g cm-3, lambda(Mo K alpha) = 0.71073 A, mu = 21.8 cm-1, F(000) = 412, T = 296 +/- 1 K, final R = 0.028 for 2369 observed reflections. Since a D-chiral auxiliary was used the configuration at the alpha-carbon was R as expected. The two carbonyls are aligned in opposite directions to each other to overcome van der Waals repulsions.

Aminobutyrates↗

Self-report of family histories of learning difficulties.

Self-reports of learning difficulties by parents of reading disabled children may be inflated because of recall bias. A retrospective study of the association between specific reading disabilities and familial reports of learning difficulties indicated the relative odds of being reading disabled for those whose relatives reported learning difficulties compared with children whose relatives did not report learning difficulties was statistically significant if fathers or siblings reported learning difficulties. No significant association was found between mothers' self-reports of learning difficulties and a diagnosis of specific learning disabilities in their children. The results support the association between specific reading disabilities and self-reported histories of academic problems in the father or siblings, but not in mothers of learning disabled children. The results suggest that reports of learning difficulties among mothers of reading disabled children may be inflated because of recall bias.

Achievement↗

The prevalence and correlates of behaviour problems in learning disabled children.

A retrospective cross sectional study of the prevalence of emotional problems among 502 learning disabled children seen in a specialized learning centre was conducted. Learning disabled children, diagnosed by an experienced clinician, were tested for emotional disturbances using the Child Behavior Checklist. The prevalence of behaviour problems among these children was 43%. This was much higher than the ten percent expected when this measure is used in a general population. There was no greater frequency of behaviour problems in children referred by teachers than in those referred by parents. Results of logistic regression analyses reveal that children who were adolescents, from non intact families, or from lower social class backgrounds had an increased odds of having behaviour problems. The implications of these findings are examined, especially in light of possible methodological problems including selection bias, which may account for the association between emotional problems and learning disabilities found in other studies.

Child↗

Fortysomething: recognizing faces at one's 25th reunion.

Twenty-four to 26 years after their high school graduation, subjects matched 40 photographs of former classmates taken from the high school yearbook with 40 current photographs of these same former classmates. Compared with age-matched control subjects who had no prior familiarity with the persons depicted in the photographs, the former classmates were superior at matching the old and new photographs. Generally, same-orientation photographs (i.e., old and new photographs taken from the same side) were matched more accurately than different-orientation photographs. Prior familiarity, however, rendered the orientation factor unimportant. These findings are discussed in terms of the processes that underlie facial recognition over very long intervals and in terms of their psycholegal implications.

Adult↗

Phonological awareness and spelling in normal children and dyslexics: the case of initial consonant clusters.

We investigated phonological awareness and spelling skills among normal readers and spellers in Grades 1 and 2 and among dyslexics who scored at the same level as the normals on a standardized spelling test. Both normal children and dyslexics had difficulty with consonants in word-initial clusters in a phoneme recognition task and a phoneme deletion task. Also, both groups of children had trouble producing legal spellings of syllables with initial clusters, sometimes failing to represent the second consonants of the clusters. The dyslexics' phonological awareness and spelling skills were poorer than those of the younger normal children, but the two groups showed similar patterns of performance.

Attention↗

Not all nonwords are alike: implications for reading development and theory.

Three experiments were designed to examine children's and adults' ability to pronounce consonant-vowel-consonant (CVC) nonsense words. Some of the nonwords, like tain and goach, shared their VC unit with a number of real words. Other nonwords, like goan and taich, shared their VC unit with few or no real words. Pooling across items, the very same grapheme-phoneme correspondences occurred in the two types of nonwords. First graders, good and poor third grade readers, and adults all performed better on the nonwords with the more common VC units than on the nonwords with the less common VC units. Although readers appeared to use VC units in the pronunciation of nonwords, we did not find evidence for use of initial CV units. Implications of the results for reading development, dyslexia, and models of nonword pronunciation are discussed.

Attention↗

The role of linguistic and visual information in spelling: a developmental study.

This study investigated the processes that elementary school children use for spelling. Good and poor spellers in grades 3 through 6 spelled words and nonwords that differed in the types of information (phonological, orthographic, morphological, or visual) that could be used to produce their correct spelling. A multiple choice spelling recognition task was also administered. Error rates on words and nonwords were related to the type of information that could be used to determine the correct spelling. Words that could be spelled on the basis of linguistic information were easier than words that could be spelled only on the basis of visual information. While children were sensitive to the linguistic properties of the stimuli, their use and knowledge of various sources of linguistic information was not uniformly developed. Children had the most difficulty with spellings based on morphological information and the least difficulty with those based on invariant sound-spelling relationships. On the dictation and the nonword tasks, younger children and poorer spellers differed from older children and better spellers in the overall level of their knowledge, but all children showed a similar pattern of results suggesting that they did not use different processes to spell words. However, the data from the recognition task suggested that poor spellers may rely more on visual information than good spellers.

Achievement↗