Initiation of evasive manoeuvres during self-motion: a test of three hypotheses

To understand performance of evasive and interceptive actions it is important to know how people decide when to initiate a movement—initiating at the right moment is often essential for successful performance. It has been proposed that initiation is triggered when a perceptually derived quantity reaches an invariant criterion value. Candidate quantities include time-to-collision (TTC), distance, and rate of image expansion (ROE), all of which have received empirical support. We studied initiation of an evasive manoeuvre in a computer-simulated steering task in which the observer was required to steer through a stationary visual environment and avoid colliding with an obstacle in their path. The results could not be explained by hypotheses which propose that evasive manoeuvre initiation is based on a fixed criterion value of TTC or distance. The overall pattern was, however, consistent with the use of a criterion ROE value. This was further tested by analyses designed to directly evaluate whether the ROE value used to initiate the response was the same across experimental conditions. Only two of the six participants showed evidence for using the ROE strategy.     

The relationship between smoking and age at the menopause: A systematic review

Context and objectiveIncreasing life expectancy has made it ever more important to study the factors that influence the age at the menopause, given that when it is reached outside of the normal range, it is associated with increased risk of osteoporosis and cardiovascular diseases, among other conditions. Among the factors studied in relation to early menopause, smoking is prominent. Destruction of the ovarian follicles is one of the mechanisms postulated for this effect. The aim of this study was to review and describe the associations between age at the menopause and the habit of smoking, its duration and its intensity.MethodA systematic review of the literature indexed in the MEDLINE and LILACS databases was conducted, without restriction on publication date. After initially identifying 1325 articles and preselecting 161 articles for consideration of their complete texts, 96 articles reporting on the results from 109 studies were selected for analysis.ResultsA great majority of the studies reported an association between the habit of smoking and early menopause, but there was no clear evidence that the duration of smoking and quantity of cigarettes smoked had any association with age at the natural menopause.ConclusionAdditional studies are needed, preferably of prospective nature and with a large number of women, in order to deepen the knowledge of the effects of various aspects of smoking on age at the menopause. Experimental studies on animals may also contribute towards clarifying the physiopathological mechanisms through which smoking influences age at the menopause.     

The relationship between smoking and age at the menopause: A systematic review

Context and objective

Increasing life expectancy has made it ever more important to study the factors that influence the age at the menopause, given that when it is reached outside of the normal range, it is associated with increased risk of osteoporosis and cardiovascular diseases, among other conditions. Among the factors studied in relation to early menopause, smoking is prominent. Destruction of the ovarian follicles is one of the mechanisms postulated for this effect. The aim of this study was to review and describe the associations between age at the menopause and the habit of smoking, its duration and its intensity.

Method

A systematic review of the literature indexed in the MEDLINE and LILACS databases was conducted, without restriction on publication date. After initially identifying 1325 articles and preselecting 161 articles for consideration of their complete texts, 96 articles reporting on the results from 109 studies were selected for analysis.

Results

A great majority of the studies reported an association between the habit of smoking and early menopause, but there was no clear evidence that the duration of smoking and quantity of cigarettes smoked had any association with age at the natural menopause.

Conclusion

Additional studies are needed, preferably of prospective nature and with a large number of women, in order to deepen the knowledge of the effects of various aspects of smoking on age at the menopause. Experimental studies on animals may also contribute towards clarifying the physiopathological mechanisms through which smoking influences age at the menopause.     

A distance effect in a manual aiming task to remembered targets: a test of three hypotheses

It has been noted that manual aiming error and variability when pointing to remembered targets increase as a function of target eccentricity. In the present study we evaluated which one of three hypotheses (target localization, motor, or movement duration) best explains this 'distance effect'. In experiment 1, older and younger participants aimed with their unseen hand at the remembered location of targets distributed between 129 and 309 mm from the starting base. Target presentation time was of either 50 or 500 ms and aiming movements could be initiated following either a 100- or a 10,000-ms recall delay. Participants had either no constraints concerning movement time or were asked to reach the near target in a longer movement time than the farther targets. The results revealed a significant distance effect when no time constraints were imposed but showed a significantly reversed distance effect when the instructions were to reach the near targets in a longer movement time than the far targets. The same results were obtained regardless of target presentation time, recall delay, or age of the participants. These results supported a movement duration interpretation of the distance effect. In experiment 2, a distance effect was replicated when pointing with one's unseen hand toward a remembered target but did not take place when pointing to visible targets. Taken together these results suggest that prolonged movement execution interferes with the stored egocentric target representation.     

The influences of dexamethasone levels on the predictive value of the DST for unipolar major depression and the relationships between post-dexamethasone cortisol and ACTH levels

To investigate the relationships between dexamethasone (DEX) and post-DEX cortisol and adrenocorticotropic hormone (ACTH) levels, the authors measured DEX at 8.00 a.m. and post-DEX cortisol and ACTH levels at 8.00 a.m. and 4.00 p.m. in 72 depressed patients categorized according to DSM-III. Cortisol non-suppressors exhibited significantly (P = 0.0006) decreased levels of DEX compared to suppressors. DEX levels at 8.00 a.m. explained 21.1% of the variance in the post-DEX cortisol values at 8.00 a.m. and 34.5% of those at 4.00 p.m. DEX levels were not significantly different among minor depressives (300.40, 309.00), major depressives without melancholia (296.X2) or with melancholia and/or psychotic features (296.X3, 296.X4). In the latter the post-DEX cortisol was significantly increased compared to all other depressives and these differences remained significant even after adjusting for the variations in DEX (by means of regression analysis). Also the diagnostic performance of the post-DEX cortisol values for major depression with associated features versus minor depression was not substantially affected when the DEX levels were accounted for. ACTH levels after DEX were shown to correlate significantly (P less than 0.05) and negatively with DEX. Although post-DEX ACTH levels did not differ among the DSM-III diagnostic categories, cortisol non-suppressors averaged significantly (P = 0.0004) higher ACTH levels than suppressors.     

人巨细胞病毒宫内感染与孕龄的关系

目的研究孕龄与人巨细胞病毒宫内感染的垂直传播率之间的关系。方法分别应用ELISA方法和PCR方法检测273例不同孕龄的孕妇外周血标本中的HCMV-IgM和HCMV-DNA,新生儿血样或胚胎组织用PCR方法检测HCMV-DNA以诊断先天性HCMV感染。结果孕早期妇女外周血中的HCMV-IgM和HCMV-DNA的阳性率均低于孕中期和孕晚期妇女,差异有显著性(P<0.005)。孕中期和孕晚期妇女宫内感染的垂直传播率显著高于孕早期妇女,差异有统计学意义(P<0.001)。结论孕中期和孕晚期妇女发生宫内感染的几率和垂直传播率均显著大于孕早期妇女,应加强对孕中期和孕晚期HCMV感染孕妇的监测和治疗。     

A test between two hypotheses and a possible third way for the control of prehension

We used an obstacle avoidance task to test two opposing accounts of how the nervous system controls prehension. The visuomotor account supposes that the system independently controls the grip formation and transport phase of prehensile movements. In contrast, the digit channel hypothesis suggests that the system controls the thumb and finger more or less independently. Our data strongly favoured the traditional visuomotor channel hypothesis and demonstrated that the time taken to grasp an object in the presence of obstacles was well predicted by a Fitts' law relationship. We suggest a "thirdway" hypothesis in order to retain the advantages of the digit channel hypothesis within the visuomotor framework. The third-way hypothesis suggests that the nervous system selects a single digit to transport to the object. We speculate that the actual digit selected might depend upon attention and the nature of the prehension task. This hypothesis is able to account for most of the empirical findings unearthed by researchers investigating the control of prehension.     

The unipolar-bipolar depressive dichotomy and the relationship between afternoon prolactin and cortisol levels

Afternoon prolactin and cortisol levels were measured in 29 patients suffering from a current major depressive episode. Among the 15 unipolar depressed patients the afternoon prolactin and cortisol levels were positively correlated, but 14 bipolar depressed patients did not show a similar relationship, and had prolactin levels lower than the unipolar patients. This finding adds to the growing list of ways in which the neurobiology of bipolar and unipolar depression may differ.     

The regulation of serum sodium in septal lesioned rats: A test of two hypotheses

The increased water intake of septal lesioned rats may be due to an inability to concerve body water and thus may be a response to systemic dehydration. Alternatively, the response may be due to removal of inhibition of hypovolemic thirst. These hypotheses were tested by measuring the external water exchange and the regulation of serum sodium concentration of septal lesioned rats during deprivation of food and water and during hypovolemia. Contrary to these predictions, septal lesioned drinkers were found to conserve body water and to regulate their levels of serum sodium concentration appropriately.     

The relationship between cortisol, salivary alpha-amylase, and cognitive bias in young women

Both animal and human studies suggest that cognitive bias toward negative information, such as that observed in major depression, may arise through the interaction of cortisol (CORT) and norepinephrine (NE) within the amygdala. To date, there is no published account of the relationship between endogenous NE and CORT levels and cognitive bias. The present study examined salivary CORT and salivary alpha-amylase (sAA), an indirect measure of NE, in relation to masked affective priming of words in young female participants. Women with higher salivary CORT showed increased priming to negative word pairs only when sAA was also high; when sAA was low, no effect of CORT on priming was observed. These results are in line with previous research indicating that increased CORT is linked to enhanced processing of negative information. However, our findings extend this literature in providing evidence that CORT predicts enhanced processing of negatively valenced information only in the presence of higher sAA.     

Depression and chronic illness: a test of competing hypotheses

No Indonesian studies have addressed the relationship between chronic illness and depression. Using simultaneous equation modeling, this study modeled the joint dependency of depression and chronic illness. The findings showed that the odds of having at least two chronic health conditions increase with the level of depression and individuals with at least two chronic health conditions have higher odds of being in a higher depression category. The health benefits of education are greater among Indonesian women after controlling for mobility, age, marital status, and smoking. Policies directed toward reducing gender differences in education are crucial to reduce persistent health inequalities.     

The relationship between sex-role orientation and the type A behavior pattern: a test of the main effect hypothesis

Examined the relationship between sex-role orientation and the Type A behavior pattern. Eighty undergraduates were classified as high or low on masculinity and femininity on the basis of Bem Sex Role Inventory (BSRI) formed on student Jenkins Activity Survey (JAS) scores for pooled Ss, for males, and for females; each yielded a main effect for masculinity. JAS scores were correlated positively with BSRI Masculinity scores and not correlated with BSRI Femininity scores across pooled Ss, across males, and across females. These results are discussed in terms of their research and treatment implications.     

The relationship between long-term job strain and morning and evening saliva cortisol secretion among white-collar workers

The objective of this study was to assess long-term job strain impact on morning and evening salivary cortisol secretion. In all 77 white-collar workers (31% women; sample mean age, 42 years at baseline) volunteered to sample morning (immediately after waking up) and evening (10 p.m.) salivary cortisol for 7 consecutive days. By median split on aggregated self-reported isostrain from three consecutive questionnaires distributed in a period of approximately 3.5 years the participants were classified into a high or low long-term isostrain condition. Regardless of strain condition, there was a significant reduction in morning salivary cortisol secretion from the working week to the weekend, whereas evening salivary cortisol secretion showed no significant variation during the week. Although chronic isostrain did not affect the morning saliva cortisol measures, evening cortisol secretion was significantly elevated in the chronic high isostrain group throughout the whole week. The elevated evening cortisol measures associated with chronic high strain are concordant with the findings in other studies on long-term strain.