Psychological test performance during climatic heat stress from dessert winds

The influence of climatic heat stress (Sharav) on the performance of subjects tested routinely at the Industrial Psychology Laboratory was studied on two groups of subjects. Candidates for office jobs and candidates for technological jobs, or candidates for courses at technological institutes. It was found that subjects tested on Sharav days had higher scores on neuroticism and extraversion and scored significantly lower than controls on intelligence tests, substitution, mechanical comprehension, and instructions. Climatic heat stress did not seem to influence performance on arithmetic, clerical ability and visual perception tests.     

The Curvilinear Relationship between State Neuroticism and Momentary Task Performance

A daily diary and two experience sampling studies were carried out to investigate curvilinearity of the within-person relationship between state neuroticism and task performance, as well as the moderating effects of within-person variation in momentary job demands (i.e., work pressure and task complexity). In one, results showed that under high work pressure, the state neuroticism–task performance relationship was best described by an exponentially decreasing curve, whereas an inverted U-shaped curve was found for tasks low in work pressure, while in another study, a similar trend was visible for task complexity. In the final study, the state neuroticism–momentary task performance relationship was a linear one, and this relationship was moderated by momentary task complexity. Together, results from all three studies showed that it is important to take into account the moderating effects of momentary job demands because within-person variation in job demands affects the way in which state neuroticism relates to momentary levels of task performance. Specifically, we found that experiencing low levels of state neuroticism may be most beneficial in high demanding tasks, whereas more moderate levels of state neuroticism are optimal under low momentary job demands.     

The impact of Sharav weather conditions on airborne pollen in Jerusalem and Tel Aviv (Israel)

Pollen grains have been a major focus of research mostly in temperate regions due to their effects on human health, especially allergies and asthma. The current study investigates a subtropical region characterized by a Mediterranean climate where Sharav conditions are experienced during the spring and autumn. The aim of the current study was to investigate whether Sharav conditions impacted airborne pollen concentrations of allergenic Amaranthaceae, Poaceae, Morus, Pinus, and Quercus more than standard Warm days during the main pollen seasons in the years 2010–2014 in Tel Aviv and Jerusalem (Israel). Slight variation was observed between the main pollen seasons in Tel Aviv compared to Jerusalem resulting from differences in temperature and relative humidity percentages. Additionally, more Sharav conditions occurred in Jerusalem than in Tel Aviv during the study period. The highest pollen concentrations occurred during Sharav days for Amaranthaceae, Poaceae, and Pinus but not for Morus and Quercus. Therefore, individuals who are allergic to Amaranthaceae, Poaceae, and Pinus pollen, and exposed to high pollen concentrations during Sharav days, might suffer more allergy symptoms than on Warm days.     

齐口裂腹鱼幼鱼疲劳后游泳特性恢复状况研究

以中国地质公园（神农架）野生动物繁育基地提供的齐口裂腹鱼（Schizothorax prenanti）幼鱼（体长为14.017.5 cm,体重为39.665.6 g）为研究对象,利用自制鱼类游泳特性（Swimming performance）研究装置,运用递增流速法（Stepped velocity test）,研究了鱼类疲劳后20d和40d的游泳特性恢复状况。结果表明:（1）在20d内齐口裂腹鱼临界游泳速度（Critical swimming speed,Ucrit）相比于初次测试（20d前）有所降低,20d内的恢复状况较差;而在40d后,临界游泳速度已经基本恢复到最初状况,40d内的恢复状况较好。（2）疲劳后鱼类游泳效率显著下降,并且在40d后无法恢复正常。虽然40d后速度指数低于20d后速度指数,40d后游泳效率高于20d后游泳效率,但是相对于初次测试,40d后游泳效率恢复效果并不明显。（3）齐口裂腹鱼在疲劳后40d内,恢复能力（Recovery capability）无法恢复到正常状况,但由于3次测试中疲劳后过量耗氧（Excess post-exercise oxygen cost,EPOC） 波动并不大,说明疲劳对其恢复能力影响并不大。（4）20d后和40d后无氧呼吸时间均较第一次测试时提前,说明疲劳损伤对其有氧呼吸能力产生了持续影响。（5）疲劳对鱼类生态行为（Ecological behavior）影响不明显。研究有利于为鱼道建设提供基础资料,对生物多样性保护具有深远意义。       

Effects of personality traits on the manifestations of irritable bowel syndrome

Objective

Previous studies have reported that patients with irritable bowel syndrome (IBS) show high neuroticism. However, the precise association between the IBS subtypes and the degree of neuroticism in younger populations is largely unknown. We tested our hypothesis that subjects with diarrhea-predominant IBS may have a higher degree of neuroticism than subjects without IBS or those with other subtypes of IBS. We also verified the additional hypothesis that the severity of neuroticism might be correlated with the severity of IBS in younger populations.

Methods

We conducted a cross-sectional survey of 557 university students, ranging in age from 18 to 21 years. Presence/ absence of IBS and determination of the IBS subtype was by the Rome II Modular Questionnaire, while the severity of IBS was determined by the IBS severity index (IBS-SI). The degree of neuroticism was evaluated using the Maudsely Personality Inventory (MPI). The presence/absence of psychological distress was measured with the K6 scale.

Results

Neuroticism scores in the subjects with diarrhea-predominant IBS were significantly higher than those in the non-IBS subjects or subjects with constipation-predominant IBS. The neuroticism scores were significantly correlated with the IBS-SI scores in all subjects with IBS.

Conclusion

These results suggest that neuroticism is involved in the pathophysiology of IBS in young subjects, especially in that of the diarrhea-predominant subtype.

     

Force control of quadriceps muscle is bilaterally impaired in subacute stroke

We tested the hypothesis that force variability and error during maintenance of submaximal isometric knee extension are greater in subacute stroke patients than in controls and are related to motor impairments. Contralesional (more-affected) and ipsilesional (less-affected) legs of 33 stroke patients with sufficiently high motor abilities (62 ± 13 yr, 16 ± 2 days postinjury) and the dominant leg of 20 controls (62 ± 10 yr) were tested in sitting position. After peak knee extension torque [maximum voluntary contraction (MVC)] was established, subjects maintained 10, 20, 30, and 50% of MVC as steady and accurate as possible for 10 s by matching voluntary force to the target level displayed on a monitor. Coefficient of variation (CV) and root-mean-square error (RMSE) were used to quantify force variability and error, respectively. The MVC was significantly smaller in the more-affected than less-affected leg, and both were significantly lower than in controls. The CV was significantly larger in the more-affected than less-affected leg at 20 and 50% MVC, whereas both were significantly larger compared with controls across all force levels. Both more-affected and less-affected legs of patients showed significantly greater RMSE than controls at 30 and 50% MVC. The CV and RMSE were not related to the Fugl-Meyer motor score or to the Rivermead Mobility Index. The CV negatively correlated with MVC in controls but only in the less-affected leg of patients. It is concluded that isometric knee extension strength and force control are bilaterally impaired soon after stroke but more so in the more-affected leg. Future studies should examine possible mechanisms and the evolution of these changes.     

Correlations of the Characteristics of Evoked EEG Potentials with the Neuroticism Level in Healthy Adults

We studied correlations between the estimates of the neuroticism level (one of the most significant factors of the emotional sphere of a personality) and the amplitude/time characteristics of evoked EEG potentials (EPs). Passive and negative emotiogenic, as well as neutral (from the emotional aspect) visual images (stimuli from the set of the International Affective Picture System, IAPS), were presented to 102 tested persons. The neuroticism level was estimated based on Eysenck’s personality questionnaire. We found that subjects with high estimates of the neuroticism level are characterized, in general, by somewhat higher rates and intensities of processing of emotionally negative information, a higher level of activation of the processes of automatic attention, and readiness to react to both significant and insignificant visual signals (with the aim of probably fighting of a threat). These peculiarities were manifested as relatively shorter latencies of the Р1, N1, Р2, N2, and Р3 components and as higher amplitudes of the Р2 component in the EPs induced by emotionally negative stimuli, as compared with the corresponding indices in subjects with a low neuroticism level. The amplitudes of the N2 component in the case of presentation of negative and neutral stimuli showed a trend toward a decrease. The approach used can be applied for obtaining objective indices interpreted as correlates of peculiarities of the emotional responsiveness typical of a personality.     

Psychosis-Proneness and Neural Correlates of Self-Inhibition in Theory of Mind

Impaired Theory of Mind (ToM) has been repeatedly reported as a feature of psychotic disorders. ToM is crucial in social interactions and for the development of social behavior. It has been suggested that reasoning about the belief of others, requires inhibition of the self-perspective. We investigated the neural correlates of self-inhibition in nineteen low psychosis prone (PP) and eighteen high PP subjects presenting with subclinical features. High PP subjects have a more than tenfold increased risk of developing a schizophrenia-spectrum disorder. Brain activation was measured with functional Magnetic Resonance Imaging during a ToM task differentiating between self-perspective inhibition and belief reasoning. Furthermore, to test underlying inhibitory mechanisms, we included a stop-signal task. We predicted worse behavioral performance for high compared to low PP subjects on both tasks. Moreover, based on previous neuroimaging results, different activation patterns were expected in the inferior frontal gyrus (IFG) in high versus low PP subjects in self-perspective inhibition and simple response inhibition. Results showed increased activation in left IFG during self-perspective inhibition, but not during simple response inhibition, for high PP subjects as compared to low PP subjects. High and low PP subjects showed equal behavioral performance. The results suggest that at a neural level, high PP subjects need more resources for inhibiting the self-perspective, but not for simple motor response inhibition, to equal the performance of low PP subjects. This may reflect a compensatory mechanism, which may no longer be available for patients with schizophrenia-spectrum disorders resulting in ToM impairments.     

Measuring activity patterns using actigraphy in multiple sclerosis

Multiple sclerosis (MS) is a demyelinating disease resulting in impairments in motor and mental performance and restrictions in activities. Self-report instruments are commonly used to measure activity patterns; alternatively, actigraphs can be placed on several parts of the body. The aims of this study were to evaluate the superiority and specificity of actigraph placement (wrist vs. ankle) in subjects with MS and healthy controls and explore the relationship between self-report and objective activity patterns. A total of 19 subjects with definite MS and 10 healthy volunteers wore actigraphs on the non-dominant wrist and ankle for three days while they kept a log to register performed activities every .5 h. Wrist and ankle actigraphs produced similar activity patterns during the most active hours (09:00-20:30 h) (ANOVA, time×location interaction: F=.901, df=23, p=.597) in individuals with MS and healthy controls (between subjects factor F=3.275, p=.083). Wrist placement of the actigraphs was better tolerated than ankle placement. Wrist actigraph data corresponded to a higher degree with self-reported activities of the upper limbs in the early afternoon, whereas ankle data seem to reflect better whole body movements in the later afternoon/early evening. Overall, actigraph data correlated moderately with self-reported activity (r=.57 for ankle and r=.59 for wrist). The regression model revealed that self-reported activities explained 44% of the variance in ankle and 50% of wrist data. Wrist and ankle actigraphs produce similar activity patterns in subjects with MS and in healthy controls; however, the placement of actigraphs on the wrist is better tolerated. Ankle actigraphs reflect general movement but underestimate upper body activity. Subjective registration of activity level partly matches with objective actigraph measurement. A combination of both objective and subjective activity registration is recommended to evaluate the physical activity pattern of subjects with MS.     

Moderate prenatal carbon monoxide exposure produces persistent, and apparently permanent, memory deficits in rats

The effects of moderate (150 +/- 2 ppm) prenatal carbon monoxide (CO) exposure (maternal HbCO concentrations of 15.6 +/- 1.1%) on learning and memory were assessed in young and aged adult rats using a two-way active avoidance paradigm. In experiment 1, the prenatal CO-exposed rats at 120 days of age acquired a conditioned avoidance response equally well as control animals in a 100-trial session. However, following a 24-hr interval the CO-exposed rats failed to demonstrate significant retention of the task as indicated by the absence of significant improvement in performance over the indicated by the absence of significant improvement in performance over the previous day; control subjects did show significant retention. In experiment 2, in which 120-day-old animals received 50 training trials per day until a criterion of ten consecutive avoidance responses was met, the prenatal CO-exposed subjects again acquired the task as well as control animals. When tested for retention 28 days later, a significant memory impairment was again observed in terms of trials required to reattain the avoidance criterion as well as in total percent avoidance responding. In neither experiment did an analysis of initial or average latency to escape the footshock stimulus reveal any significant alterations. These latter results suggest that the observed performance impairment reflected a memory deficit and not a disruption of sensory, motor, or motivational factors. In experiment 3, prenatal CO-exposed rats approximately 1 year of age (300-360 days of age) showed impairment relative to air-exposed controls in both the original learning and retention of the two-way avoidance response. Again, however, there was no evidence for alterations in performance factors per se. Collectively these data indicate that while young adult rats prenatally exposed to 150 ppm CO demonstrate an associative deficit restricted to memory impairment, aged adults similarly exposed during the prenatal period display a more pronounced deficit similar to that recently reported for animals tested as juveniles. The importance of parametric manipulations in uncovering long-term toxicity is also discussed.     

Neuroticism modifies psychophysiological responses to fearful films

Background

Neuroticism is a personality component frequently found in anxious and depressive psychiatric disorders. The influence of neuroticism on negative emotions could be due to its action on stimuli related to fear and sadness, but this remains debated. Our goal was thus to better understand the impact of neuroticism through verbal and physiological assessment in response to stimuli inducing fear and sadness as compared to another negative emotion (disgust).

Methods

Fifteen low neurotic and 18 high neurotic subjects were assessed on an emotional attending task by using film excerpts inducing fear, disgust, and sadness. We recorded skin conductance response (SCR) and corrugator muscle activity (frowning) as indices of emotional expression.

Results

SCR was larger in high neurotic subjects than in low neurotics for fear relative to sadness and disgust. Moreover, corrugator activity and SCR were larger in high than in low neurotic subjects when fear was induced.

Conclusion

After decades of evidence that individuals higher in neuroticism experience more intense emotional reactions to even minor stressors, our results indicate that they show greater SCR and expressive reactivity specifically to stimuli evoking fear rather than to those inducing sadness or disgust. Fear processing seems mainly under the influence of neuroticism. This modulation of autonomic activity by neurotics in response to threat/fear may explain their increased vulnerability to anxious psychopathologies such as PTSD (post traumatic stress disorder).     

The relationship between chronotype and personality among patients with alcohol dependence syndrome: Pilot study

The study investigates the distribution of chronotypes among alcohol-dependent subjects and the relationship between personality and chronotype. Fifty-eight alcohol-dependent patients and 29 age-matched healthy controls were studied using Ogińska’s Chronotype Questionnaire (ChQ), Eysenck’s Personality Questionnaire – Revised (EPQ-R), Selzer’s Michigan Alcoholism Screening Test (MAST) and a sociodemographic status questionnaire designed by the authors. The alcohol-dependent patients tended to be morning type, based on the morningness–eveningness ChQ scale, with a weakly marked rhythm, based on the distinctness ChQ scale. Preference towards morningness was associated with older age, but no relation between chronotype and severity of alcohol dependence was found. A high amplitude of the rhythm was associated with higher neuroticism. Therefore, despite being in the minority, patients with a distinct circadian rhythm (i.e. with a high amplitude) are at greater risk of mood and anxiety disorders and hence should be given special consideration.     

5‐HTTLPR S‐allele: a genetic plasticity factor regarding the effects of life events on personality?

The S-allele of the 5-HTTLPR has been identified as a genetic vulnerability factor, being associated with an increased risk for affective disorders and/or maladaptive traits (e.g. neuroticism), especially after exposition to negative life-events (LEs). Alternatively, it has been hypothesized that this genetic risk factor might constitute a genetic plasticity factor. That is, S-allele carriers are not only vulnerable to the negative effects of a preponderance of stressful LEs but also disproportionally benefit from a preponderance of positive environmental influences. We tested this hypothesis in 357 subjects who were genotyped for the 5-HTTLPR and provided self-reports of neuroticism, life-satisfaction and LEs. Results showed a relatively increased number of positive LEss to be associated with reduced neuroticism (men: β = -0.501, P < 0.05, women: β = -0.369, P < 0.005) and increased life satisfaction (β = 0.494, P < 0.001) within SS-homozygotes. Within SL-heterozygotes, similar tendencies were found. No associations were detected in LL-homozygotes. Extreme Group comparisons revealed a genotype × LE interaction (F(2,198) = 5.593, P < 0.005), with SS-homozygotes having experienced predominantly positive LEs exhibiting reduced neuroticism (women: F(1,34) = 4.764, P < 0.05; men: F(1,17) = 2.092, P = 0.17), and increased life satisfaction (F(1,53) = 4.057, P < 0.05), as compared to LL-homozygotes having experienced predominantly positive LEs. Our data support the idea that the S-allele of the 5-HTTLPR is associated with an overall increased reactivity to environmental influences, be they positive or negative in nature. These findings constitute a promising add-on to earlier data and support the plasticity hypothesis.     

Measuring Activity Patterns Using Actigraphy in Multiple Sclerosis

Multiple sclerosis (MS) is a demyelinating disease resulting in impairments in motor and mental performance and restrictions in activities. Self‐report instruments are commonly used to measure activity patterns; alternatively, actigraphs can be placed on several parts of the body. The aims of this study were to evaluate the superiority and specificity of actigraph placement (wrist vs. ankle) in subjects with MS and healthy controls and explore the relationship between self‐report and objective activity patterns. A total of 19 subjects with definite MS and 10 healthy volunteers wore actigraphs on the non‐dominant wrist and ankle for three days while they kept a log to register performed activities every. 5 h. Wrist and ankle actigraphs produced similar activity patterns during the most active hours (09∶00–20∶30 h) (ANOVA, time×location interaction: F=.901, df=23, p=.597) in individuals with MS and healthy controls (between subjects factor F=3.275, p=.083). Wrist placement of the actigraphs was better tolerated than ankle placement. Wrist actigraph data corresponded to a higher degree with self‐reported activities of the upper limbs in the early afternoon, whereas ankle data seem to reflect better whole body movements in the later afternoon/early evening. Overall, actigraph data correlated moderately with self‐reported activity (r=.57 for ankle and r=.59 for wrist). The regression model revealed that self‐reported activities explained 44% of the variance in ankle and 50% of wrist data. Wrist and ankle actigraphs produce similar activity patterns in subjects with MS and in healthy controls; however, the placement of actigraphs on the wrist is better tolerated. Ankle actigraphs reflect general movement but underestimate upper body activity. Subjective registration of activity level partly matches with objective actigraph measurement. A combination of both objective and subjective activity registration is recommended to evaluate the physical activity pattern of subjects with MS.     

The effects of creatine loading on thermoregulation and intermittent sprint exercise performance in a hot humid environment

The purpose of this study was to determine the effects creatine (Cr) loading may have on thermoregulatory responses during intermittent sprint exercise in a hot/humid environment. Ten physically active, heat-acclimatized men performed 2 familiarization sessions of an exercise test consisting of a 30-minute low-intensity warm-up followed by 6 x 10 second maximal sprints on a cycle ergometer in the heat (35 degrees C, 60% relative humidity). Subjects then participated in 2 different weeks of supplementation. The first week, subjects ingested 5 g of a placebo (P, maltodextrin) in 4 flavored drinks (20 g total) per day for 6 days and were retested on day 7. The second week was similar to the first except a similar dose (4 x 5 g/day) of creatine monohydrate (Cr) replaced maltodextrin in the flavored drinks. Six days of Cr supplementation produced a significant increase in body weight (+1.30 +/- 0.63 kg), whereas the P did not (+0.11 +/- 0.52 kg). Compared to preexercise measures, the exercise test in the heat produced a significant increase in core temperature, a loss of body water determined by body weight change during exercise, and a relative change in plasma volume (%PVC); however, these were not significantly different between P and Cr. Sprint performance was enhanced by Cr loading. Peak power and mean power were significantly higher during the intermittent sprint exercise test following 6 days of Cr supplementation. It appears that ingestion of Cr for 6 days does not produce any different thermoregulatory responses to intermittent sprint exercise and may augment sprint exercise performance in the heat.     

Evoked potentials in the brain of adolescents in norm and those with attention deficit during recognition of short-term acoustic stimuli

The effect of stimulus duration on auditory event-related potentials and performance of oddball task was studied in normal children and those with attention-deficit symptoms. Mismatch negativity was absent on presentation of short-term (11 ms) stimuli and present with longer stimuli (50 ms). The adolescents with deficit of attention performed much worse (errors of omission) with the short stimuli. The RT was significantly larger in subjects with attention-deficit with all types of tested stimulus duration. They also manifested a smaller P3b amplitude in response to task-relevant deviant stimuli and larger N2b peaks in response to the standard stimuli. It was possible to differentiate between the MMN and the N2b components owing to the fact that the MMN was absent with shorter stimuli. The findings suggest that there is a deficit in processing of sensory information at the cortical level in subjects with the attention-deficit symptoms.     

Study of trace elements in blood of cancer patients by proton-induced X-ray emission (PIXE) analysis

Proton-induced X-ray emission (PIXE) analysis was employed to determine the concentrations of six elements in the plasma and erythrocytes of 18 cancer subjects (15 males and 3 females) with neoplastic disorders and in 70 controls (35 males and 35 females). It was found that the concentrations of Br, K, and Zn were significantly elevated in the erythrocytes of the cancer subjects compared to the controls, whereas the concentration of Fe was significantly depressed, but with no difference observed in the concentration of Ca. In the plasma, the concentrations of Br, Cu, Ca, and K were significantly elevated, whereas the concentrations of Fe and Zn were found to be significantly depressed compared to the controls.     

Sexual experience modulates neuronal activity in male Japanese quail

After an initial increase, repeated exposure to a particular stimulus or familiarity with an event results in lower immediate early gene expression levels in relevant brain structures. We predicted that similar effects would occur in Japanese quail after repeated sexual experience within brain areas involved in sexual behavior, namely, the medial preoptic nucleus (POM), the bed nucleus of stria terminalis (BST), and the nucleus taeniae of the amygdala (TnA), an avian homolog of medial amygdala. High experience subjects copulated with a female once on each of 16 consecutive days, whereas low experience subjects were allowed to copulate either once or twice. Control subjects were never exposed to a female. High experience subjects were faster to initiate sexual interaction, performed more cloacal contacts, and completed each cloacal contact faster than low experience subjects. Low experience subjects showed an increase in egr-1 (ZENK) expression, an immediate early gene product used as marker of neural activation in birds, in the areas of interest. In contrast, in high experience animals, egr-1 expression in the POM, BST, and the periaqueductal gray (PAG) was not different than the level of expression in unmated controls. These results show that experience modulates the level of immediate early gene expression in the case of sexual behavior. Our results also indicate that immediate early gene expression in specific brain areas is not necessarily related to behavioral output but depends on the behavioral history of the subjects.     

Soluble CD40 ligand levels in otherwise healthy subjects with impaired fasting glucose

Unlike diabetes mellitus and impaired glucose tolerance, it is not clear whether the subjects with impaired fasting glucose (IFG) are at increased risk of atherosclerosis and cardiovascular diseases. The CD40-CD40 ligand interaction is involved in the mechanism of atherosclerosis. We investigated whether soluble CD40L (sCD40L) as well as high sensitive C-reactive protein (hsCRP) levels are increased in subjects with IFG having no confounding factors for inflammation or atherosclerosis. Twenty four IFG subjects with no additional disorders and 40 appropriate healthy controls were studied. sCD40L and hsCRP levels in the IFG and control groups were similar. Blood pressures, total and LDL-cholesterol, and triglyceride levels were also similar, whereas HDL-cholesterol was lower and HOMA-IR indexes were higher in the IFG group. Though the sample size was small, the present data show that sCD40L seems not to alter in subjects with IFG suggesting that it might not be an independent risk factor for atherosclerosis.