Manual laterality and hitting performance in major league baseball.

Asymmetrical hand function was examined in the context of expert sports performance: hitting in professional baseball. An archival study was conducted to examine the batting performance of all Major League Baseball players from 1871 to 1992, focusing on those who batted left (n?=?1,059) to neutralize the game asymmetry. Among them, left-handers (n?=?421) were more likely to hit with power and to strike out than right-handers (n?=?638). One possible account, based on the idea of hand dominance and an analogy to tennis, is that batting left involves a double-handed forehand for left-handers and a weaker and more reliable double-handed backhand for right-handers. The results are also interpretable in the light of Y. Guiard's (1987) kinematic chain model of a between-hands asymmetrical division of labor, which provides a detailed account of why left batting is optimal for left-handers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influences of chorion type on saccadic eye movements in twins

PURPOSE: The influence of genetic and prenatal environmental factors on characteristics of saccadic performance were evaluated in young monozygotic (MZ) twins (8-19 years old) of known chorion type. METHODS: Saccadic eye movements were recorded using an infrared system. Saccadic latency, accuracy, and parameters of amplitude-peak velocity exponential equation (main sequence) were quantified. RESULTS: Intraclass correlations of saccadic parameters differed significantly from zero for monochorionic and dichorionic MZ twins. The within-pair mean squares were significantly less, and intraclass correlations were significantly higher in monochorionic than in dichorionic twins for latency and were similar for other saccadic parameters (accuracy, slope of main sequence, and peak velocity for 15 degrees saccades). CONCLUSIONS: These findings confirmed previous reports that saccadic parameters of MZ twins are significantly correlated and indicated that similarity of these parameters seen in MZ twins may be driven both by genetic and by prenatal environmental factors.     

Effects of chorion type on variation in cord blood cholesterol of monozygotic twins

Cholesterol levels were measured in the cord blood of 30 pairs of monochorionic and 22 pairs of dichorionic monozygotic (MZ) twins. Cholesterol levels were found to be significantly higher in female twins when data was combined over chorion type. The type of chorionic development had no significant effect on variation among twin pairs. Chorion type did, however, have a significant effect on the within-pair variation. The variation within dichorionic pairs was more than five times that within monochorionic pairs (P less than .01). This result suggests that the variation in placentation has a significant effect on within-pair variation in serum cholesterol of newborn MZ twins.     

Unimanual performance as a measure of laterality

The diagnosis and treatment of colorectal cancer remains a formidable health care problem. Colorectal cancer is the second most frequently diagnosed cancer in both men and women in Western countries and accounts for over 55,000 deaths annually in the United States alone. Cancer of the colon and rectum is eminently curable by surgical resection if identified early; however, despite our best efforts, patient survival from this disease has changed little over the past 50 years. With the advent of molecular and genetic techniques, a number of novel discoveries have been made in the last decade which have greatly expanded our understanding of the etiology and cellular mechanisms contributing to the development and subsequent progression of colorectal cancer. This review summarizes the recent molecular advances in the understanding of both familial (HNPCC and FAP) and sporadic colorectal cancers. The numerous scientific advances described in this review offer the promise of the development of novel chemotherapeutic agents, more accurate prognostic indicators and better screening techniques.     

Manual laterality in chimpanzees (Pan troglodytes) in complex tasks.

To determine the manual laterality of a sample of 24 chimpanzees, 4 problem apparatuses were used, the solution for which (obtaining a food item) required the use of 1 or both hands in sequential, simultaneous, or both sequential and simultaneous actions. The majority of the subjects showed significant and consistent hand preferences, especially in the actions that required a precision grip. The results obtained suggest the existence of factors linked to the specific characteristics of the task to be performed and to the ontogenetic maturation of the subject, which would influence the directionality and degree of the hand preference displayed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Control of annealing twins in type 316 austenitic stainless steel

The twinning frequency expressed as the number of coherent twin boundaries per grain has been investigated as a function of grain size in type 316 and 316L commercial austenitic stainless steels with different carbon contents as well as doped with 30ppm of boron, and subjected to various thermomechanical treatments. Experiments have established that the number of coherent twin boundaries per grain (TB/grain) for grain sizes larger than 0.1 mm, increases linearly with grain size according to the equation: TB/grain = A + K_td, where A and K_t are constants and d is the true volume grain diameter. In the ultrafine and fine grain size range from 1.5 to 100 μm the number of twins per grain is the lowest one and virtually independent of grain size. Both the increase in carbon content by 0.01% and doping with 30 ppm of boron, significantly suppress the formation of twins. Also, the rate of twins formation depends on whether twins are formed during pure grain growth or simultaneous recrystallization and grain growth. The results obtained are explained in terms of the classical Fullman-Fisher theory of twins formation.     

Limb laterality and motor proficiency in children

This investigation examined the premise derived from recent reports, that children who are consistent right-handers are better coordinated than their left- and mixed-sided (inconsistent) peers. The observation of limb laterality was extended to include footedness. Two samples of children (N = 273) (foot laterality/hand laterality), matched for age and sex, were assessed for motor proficiency and compared according to limb preference (right, mixed, left). Overall, results indicated no significant group differences (ps > .05) in composite scores (upper-limb, lower-limb, combination) and total performance, within foot and hand laterality. In view of recent studies (noting differences between laterality groups) and these nonsupportive results, it appears that additional inquiry is warranted before any consensus regarding the association between limb laterality and motor coordination can be established. Suggestions for further inquiry are presented.     

Expression of telomerase activity in human chorion

Telomerase activation is required for cellular immortalization and is found in most malignant tumors. Normal somatic cells are generally telomerase-negative, except for stem cells in renewing tissues. During pregnancy, human trophoblast continues to proliferate and acts as proliferating stem cells for the development of chorion and the formation of placenta. In the present study, a total of 105 chorions from placentas at various weeks of gestation were examined for telomerase activity using the telomeric repeat amplification protocol (TRAP) assay. Twenty-five of 33 (76%) normal early chorions at 5 to 9 weeks gestation were telomerase-positive. Chorions from early spontaneous abortions also exhibited telomerase activity but at a low level. In contrast, only 2 (4%) late chorions at 34 to 41 weeks gestation expressed telomerase activity. Significant telomerase activity was observed in trophoblast cell fractions of chorion, demonstrating trophoblast to be the source of the activity. Expression of human telomerase catalytic subunit (hTRT) was observed in early chorions, but not in late placenta, and there was a close correlation between telomerase activity and hTRT expression. In contrast, expression of human telomerase RNA component (hTR) was observed in both early and late chorions and was not liked to telomerase activity. These findings suggest that telomerase activity in chorion is critically regulated over the course of gestation, associated with hTRT expression. The findings of the present study also appear to support the emerging concept that normal somatic cells with stem cell-like characteristics can express telomerase activity.     

Manual vs robotically assisted laparoscopic surgery in the performance of basic manipulation and suturing tasks

OBJECTIVE: To compare the surgical performance of manual and robotically assisted laparoscopic instruments on basic maneuvers and intracorporeal suturing in inanimate models. DESIGN: A set of laparoscopic tasks was used to evaluate basic endoscopic movements and intracorporeal suturing: positioning a cylinder on a Peg-Board, dropping beads into receptacles, running a 25-cm rope, and capping a hypodermic needle. Intracorporeal knot tying and running a suture through predetermined points were evaluated separately. The sutures used for these tasks were 2-0 and 4-0 silk and 6-0 and 7-0 polypropylene. PARTICIPANTS: Twenty surgeons completed the set of laparoscopic tasks manually and then with a robotically assisted system. None had used the robotic system before. MAIN OUTCOME MEASURES: Time required to complete the tasks and the precision in performing them. RESULTS: The robotic system accurately reproduced the movements of the surgeons and filtered their hand tremors efficiently. In the basic tasks, operative times were significantly longer for the robotic system (P<.001). In the suturing tasks, operative times were longer with the use of the robotic system for sutures sizes 2-0 and 4-0 (P<.001). However, time differences were not significant for suture sizes 6-0 and 7-0 (P> or =.07). Precision measurements were similar for all tasks using the manual instruments and the robotically assisted system. No significant differences were found between the performance of advanced laparoscopic surgeons and laparoscopic fellows. CONCLUSIONS: Laparoscopic maneuvering and suturing is faster and just as precise when performed manually as when performed with the prototype robotic system. These differences in speed are inversely proportional to the size of the suture. Future generations of the robotic system may eliminate these differences.     

Information on type 1 diabetes mellitus and QT interval from identical twins

To determine whether QT interval is influenced by genetic factors and whether QT-interval prolongation occurs in type 1 diabetes or is related to diabetic autonomic neuropathy, QT intervals were measured, and autonomic function was assessed in 44 pairs of identical twins who were discordant for type 1 diabetes. Twins were compared with 44 normal control subjects of similar age and sex. QT intervals were corrected for heart rate (QTc). QTc in diabetic twins correlated with that in their nondiabetic co-twins (r = 0.41; p = 0.006). Diabetic twins had significantly longer QTc than did their nondiabetic co-twins and control subjects (416 +/- 18 vs 407 +/- 16 and 403 +/- 19 ms, respectively; p < 0.005). A greater number of abnormal autonomic function tests were detected in diabetic twins than in their nondiabetic co-twins and control subjects (8 vs 2 and 0%, respectively; p < 0.01). Diabetic twins with disease duration > 14 years (n = 22) had longer QTc than did their nondiabetic co-twins (420 +/- 17 vs 402 +/- 14 ms; p < 0.0005). Twins with diabetes for > 14 years had a greater frequency of abnormal autonomic function tests than did those with diabetes < 14 years (15 vs 2%; p < 0.001). QTc did not correlate with autonomic function in diabetic twins. It is concluded that QT interval is influenced by genetic factors, and in type 1 diabetes, QTc can be prolonged independently of autonomic neuropathy.     

Gesture laterality in aphasic and apraxic stroke patients

Limb preference during conversational gestures may be a reflection of functional hemispheric asymmetries. In right-handers, speech and praxis are usually mediated by the left hemisphere and in conversation, right-handers gesture more with their right than left hand. However, patients with left hemisphere brain damage, who are aphasic and apraxic but not hemiplegic, may use their right hemisphere to compensate for their left. Therefore, we investigated spontaneous lateralized gesture production during conversation in a group of left hemisphere-damaged stroke patients, who were aphasic and apraxic but not hemiparetic, and compared their performance to a group of matched controls. Whereas the control group had a strong right-hand preference, the nonparetic but apraxic and aphasic stroke patients were as likely to produce gestures with the right, left, or both hands.     

Cerebral laterality in deaf and hearing children.

Studied the development of lateralization of cerebral function in 20 hearing and 20 prelingually deaf children using the concurrent task paradigm. Ss were aged 5–6 and 11–12 yrs; all were right-handed. Concurrent processing of a nonverbal task did not cause a selective hand impairment monitored by a manual tapping task. However, deaf Ss were more impaired than hearing Ss in both age groups. Using a concurrent verbal task, both groups manifested a selective impairment of right-hand performance. The deaf also showed a greater left-hand decrement than did the hearing Ss. This result suggests that hemispheric specialization may be less apparent in the deaf than in hearing children. The factor of cognitive task difficulty is suggested as an explanation of these results. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychopathy and laterality of cerebral function.

Used a tachistoscopic recognition task to test the hypothesis that psychopathy is associated with dysfunction of the dominant hemisphere. 55 prison inmates were divided into groups with high, medium, and low ratings of psychopathy. Ss were required to identify 3-letter words presented in a vertical arrangement either in the left visual half field (LVF) or the right visual half field (RVF) 1.5° from a central fixation point. Each of 24 words was presented twice, once in each visual half field, at an exposure time of 80 msec. The exposure time was then shortened to 40 msec, and a 2nd set of 24 words was presented twice, once in each visual half field. In general, words presented in the RVF were more readily identified than those presented in the LVF. There was no evidence that psychopathy was associated with any deficit in RVF performance even when handedness and writing position were taken into account. Further, based on responses to a laterality questionnaire, there were no group differences in "left-sidedness." Results do not support the hypothesis of dominant hemisphere dysfunction in psychopathy. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dichotic-listening measures of brain laterality in mania.

Dichotic syllable and complex tone tests were used to compare performance asymmetries in 35 manic patients with 26 normal controls and to determine whether there were changes in laterality with remission of the manic state. Relationships of performance asymmetries to treatment outcome and symptom features were also examined. Compared with normal controls, manic patients showed overall poorer accuracy, particularly for complex tones presented to the left ear, and they failed to show the normal left-ear (right-hemisphere) advantage for complex tones. Abnormal laterality for complex tones was present in patients who later responded to treatment but not in nonresponders. In the euthymic state, patients showed improved left-ear accuracy for complex tones and more normal perceptual asymmetry. These findings suggest that mania is associated with a decrement in right-hemisphere processing of complex tonal information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Permeability of human chorion laeve to diazepam and meperidine

Sera from patients with hepatitis, according to clinical and biochemical data, often give a spontaneous immune adherence (S.I.A.) with O human red blood cells. In 58% of the cases the test is positive and is associated with Australia (HBs) antigen in 6.7 to 9.5% of the patients. The titer cas reach 1/8192 and seems to follow the clinical evolution. S.I.A. also occurs at low titre (less than or equal to 1/32) in 18 to 30% of the cirrhosis tested, in 17 to 22% of various diseases and in 0 to 16% of different neoplasia. In spite of the fact that S.I.A. is not specific in its principle, it may be useful as a complementary test for detection and monitoring of viral hepatitis.     

A walk in the chorion locus of Bombyx mori

We have recovered overlapping clones that represent in the aggregate a contiguous segment of chromosomal DNA 270 kb in length, or probably one third of the chorion locus of Bombyx mori. Approximately 70 genes have been identified, the majority of which are arranged in coordinately expressed pairs. The nonidentical genes expressed in the late period of choriogenesis are clustered within a single, 130 kb region, which is flanked by regions containing genes that are active during the middle developmental period. The late genes encode two families of high-cysteine proteins; the evolutionarily persistent clustering of these families contrasts sharply with the extensive sequence diversification of the structural genes and their flanking DNA elements. We discuss the possible regulatory significance of the clustered arrangement, as well as certain features of multigene family evolution.     

Amygdala-hippocampal atrophy and memory performance in dementia of Alzheimer type

The aim of the present study was to examine the involvement of brain structures, especially the amygdala-hippocampal complex, in dementia of Alzheimer type (DAT), and to assess the relation of amygdala-hippocampal atrophy with memory dysfunction. 14 patients with DAT and 10 healthy age-matched controls were examined with different neuropsychologic tests including the UCLA-Auditory Verbal Learning Test. MRI was performed with a conventional 1.5-tesla scanner. Atrophy was found in many brain structures of demented subjects in comparison with healthy age-matched controls. The volumes of amygdala-hippocampal complexes and of the temporal lobes of demented subjects were more reduced than the total brain volume and other structures. Memory dysfunction was highly correlated with atrophy of the amygdala-hippocampal complexes and of the temporal lobes. Consequently, DAT seems to affect the amygdala-hippocampal complex and their related function (i.e. memory) more than other cerebral structures, but cerebral degeneration in DAT is not restricted to these structures.     

Manual performance of a repeated pattern by older and younger adults with supplementary auditory cues.

Ss performed the same M-shaped manual movement pattern on repeated trials using a visual display of instantaneous error. With practice, Ss' effective time delays were diminished by increased anticipation as evidenced by an increased correlation of their movement patterns with the input velocity. However, younger adults had lower error scores, performed larger movements, and had shorter effective time delays than did older adults. Supplementary auditory displays additionally contributed to greater anticipation. However, men exhibited this effect most with an auditory display of input velocity and women with an auditory display of input position. This benefit of the auditory displays did not carry over after these displays were withdrawn. When the visual display was additionally withdrawn, benefits of the auditory training were manifest among the older adults as relatively greater temporal modulation of movement. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Hemispheric laterality and memory bias for threat in anxiety disorder.

Examined auditory perceptual asymmetries and explicit memory biases for threat in patients with panic disorder and generalized anxiety disorder relative to healthy control Ss. They did not find a greater explicit memory bias for threat in the anxiety patients. However, explicit memory biases for threat were associated with perceptual asymmetry scores; patients with a greater right-ear (left hemisphere) advantage exhibited an explicit memory bias for threat material, whereas patients with a lower right-ear advantage displayed apparent cognitive avoidance of threat material. Memory for threat words was unrelated to perceptual asymmetry in healthy control Ss. These findings suggest that neuropsychological variables may partly determine the degree to which anxiety patients process threatening stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Manual performance during cold exposure as a function of practice level and the thermal conditions of training.

3 groups of 10 Ss each were given varied thermal experience (warm or cold hands) during 3 weeks of training on a standard manual task. The results were as follows: (a) 1 day of cold-hand training significantly reduces the size of a manual decrement usually associated with cold exposure, but continued cold experience did not; (b) skill level on the task per se did not interact with the cold induced performance decrements; and (c) the thermal conditions associated with performance on the task appeared to become part of the stimulus complex eliciting correct manual responses when these thermal conditions were maintained for a large number of trails, i.e., the Ss learned, not merely to perform on the task, but to perform with warm, or cold hands specifically. (PsycINFO Database Record (c) 2010 APA, all rights reserved)