RESUMO

Pursuit eye movements keep the image of a small moving target near the fovea with an admixture of smooth pursuit and saccades. To probe the initiation of pursuit, four humans and one monkey attended a bright laser spot that was rear-projected on a diffusely illuminated (1 cd/m(2)) tangent screen. Movement of the viewing eye was recorded with a magnetic search coil. After presenting a stationary target for a random time (1-3 sec), the computer extinguished the target in separate trial blocks for 40, 100, 200, or 500 ms. At the end of this gap period, the target reappeared on the fovea, moving centrifugally at 10°/sec in a random direction before decelerating to a stop. The predominate initial response (< 90%) to unpredictable changes in target motions had four sequential components: a latent period, a primary smooth movement, a small saccade, and then a secondary smooth movement. None of five measured variables depended systematically on the gap duration: the latency to primary smooth pursuit (range of means 144-217 ms), average eye velocity in the first 50 msec of primary smooth pursuit (0.7-3.6°/s), latency to the first saccade (207-319 ms), amplitude of the first saccade (1.6-2.7°), or average eye velocity in the first 100 ms of the secondary smooth pursuit (7.4-11-4°/s). Our data do not support the hypothesis that a separate fixation system has to be disengaged before smooth pursuit can begin, as has been suggested for the saccadic system.

RESUMO

A commercially available rapid test (HIVCHEK) was compared with an enzyme-linked immunosorbent assay (ELISA) for identifying human immunodeficiency virus type 1 in the serum of newborn infants. Of 1309 cord blood samples tested, the HIVCHEK test detected all the true-positive samples detected by ELISA. Of the 35 samples with positive ELISA results, six had negative results on Western blot; only 1 of the 30 samples with positive HIVCHEK results had negative results on Western blot. Thus the HIVCHEK test can be used to facilitate the rapid identification of HIV-1 in the serum of newborn infants.

Assuntos

RESUMO

A patient with hydatid cyst of the presented stunted growth, normal renal function and no significant proteinuria. The radiological abdominal investigation disclosed, besides the hydatid cyst, horseshoe kidneys. Renal biopsy was performed during surgery. Immunofluorescence (direct and indirect) and immunoperoxidase studies revealed glomerular deposits of hydatid antigen and its corresponding antibody. A grade I immune complex type of membranous glomerulonephritis, without significant clinical signs, was diagnosed in association with the hepatic hydatid disease.

Assuntos

RESUMO

An observational learning paradigm was used to instruct 5 children with mild or moderate mental retardation to monitor their comprehension of inadequate instructions. Instructions were inadequate because of an interfering signal, an unfamiliar word, excessive length, or an unfamiliar idiomatic phase. Subjects' peers served as models during the training. A multiple baseline design across subjects and across instruction types was employed. All subjects learned to request clarification of the first three inadequate instructions; however, none of the children learned to request clarification of idiomatic phrases. Although all children eventually demonstrated observational learning, three children required feedback from the trainer before they began to request clarification for one or two of the instruction types. Two children generalized their requesting behavior to the interfering signal message type, suggesting that generalization may be likely to occur between similar message types. During posttesting all children generalized their requesting behavior when presented with two unfamiliar message types, sometimes using new question forms. Four of the 5 children also generalized their requesting behavior in sessions with their teachers 5-10 weeks later.

Assuntos

RESUMO

The effects of a pragmatic teaching strategy on 4 nonspeaking children's abilities to initiate requests for information (i.e., who, what, and where) using manual communication boards were investigated. A teaching strategy based on milieu teaching and time-delay procedures was developed and embedded in naturally structured communication tasks to evoke information requests. Results indicated that information requests using the communication board occurred only after the pragmatic teaching strategy was applied sequentially to the three request types during the experimental condition. This effect was demonstrated repeatedly across the 4 subjects. Although generalization across request types was not demonstrated, substantial generalization was found across partners and environments. A social validation measure confirmed the treatment effectiveness. Independent raters perceived significant differences when viewing before- and after-training videotapes on 7 of 10 communication variables for all subjects.

Assuntos

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This study investigated the effects of verbal imitation on the comprehension of novel object-location responses and subsequent transfer of these responses to production. A matrix training procedure was used to teach 2 children with moderate mental retardation syntactic rules for combining known and unknown words into two-word utterances. An alternating treatments design was used with two conditions: receptive teaching with imitation of the target phrase and no imitation of the phrase. Findings suggested that the use of imitation facilitated both generalized receptive learning and transfer to production in both subjects.

Assuntos

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Using extensive international data it is shown in detail how mortality is related to birthweight and gestation. It is demonstrated that the widely used 'birthweight for length of gestation' standards can be seriously misleading. A new 'high risk' classification is proposed.

Assuntos

RESUMO

A study was made of live birth rates, infant, neonatal, and postneonatal death rates, late fetal death ratios, and perinatal death ratios for Sweden and the United States for selected years, 1950-1973. Sweden has lower live birth rates, infant, neonatal, and postneonatal death rates, as well as lower perinatal death ratios. Data available on low-birth-weight live births for selected years, 1959-1970, for both countries indicated that rates in the United States were almost twice those in Sweden. Implications of these findings for the United States are discussed in light of the quantity, quality, and delivery of health care services, as well as of other factors in Sweden.

Assuntos

RESUMO

A stratified 3-stage random sample of 50 360 children ages 0-19 drawn from the whole population of Cuba was measured in a large-scale growth study during 1972-73. Fifteen anthropometric measurements were taken and puberty stages and menarche status were assessed. Hand-wrist radiographs were done on 10% of the sample. Information regarding the social and education status of the parents was obtained and parental heights were measured. One year later, 30% of the sample were re-measured and 10% re-X-rayed. The overall response rate was 96% at pre-school and primary school age, and a lettle less later. Quality control sessions were held at which the nine measuring teams compared results. No significant differences were found between teams working different parts of the island. Differences between duplicate measurements of stature by individual measurers had standard deviations approximating 0.20 cm. Individual measurers' means differed from the grand means of all measurers by up to +/- 0.2 cm for stature, +/- 0.4 cm for sitting height and +/- 0.5 mm (7% of mean) for triceps skinfold. One or more measurements lay outside the 3rd-97th centile limits in 21% of individuals. Scrutiny of these individuals' records resulted in elimination of measurements in amounts ranging from 0.1% (triceps skinfold) to 1.1% (crown-rump length). Problems of planning and execution of growth surveys designed to set national standards are described, and solutions given or suggested.

Assuntos