A comparison of the kinematics of the dolphin kick in humans and cetaceans

Prerecorded video footage of 9 female and 13 male Olympic level athletes swimming underwater by using the dolphin kick was analyzed and comparisons of the stroke kinematics were made with a previous analysis of cetacean swimming conducted by Rohr and Fish (Rohr, J. J., & Fish, F. E. (2004). Strouhal numbers and optimization of swimming by odontocete cetaceans. The Journal of Experimental Biology, 207, 1633-1642). The velocities of the swimmers ranged from 1.12 m/s to 1.85 m/s which corresponded to a range of effort levels. While some swimmers performed the dolphin kick on their backs (dorsal), others employed the prone (ventral) or the side (lateral) position and no distinctions were made between these positions when considering the results. The raw quantities measured were body length L (from the fingertips of the outstretched arms to the tips of the toes), time T(L) taken by the swimmer to traverse a body length, kick amplitude A at the toes, and the number of video frames per kick. These allowed us to determine the average velocity U of the swimmer, the kick frequency f, the reduced or length-specific velocity U/L (body lengths traversed per second), and the non-dimensional quantities kick amplitude A/L, the Strouhal number fA/U (ratio of tip or toe speed to forward speed) and the quantity fL/U (kicks per body length traversed). Trends of these dimensional and non-dimensional quantities were examined for the swimmers and compared to the cetaceans. Results showed that humans and cetaceans have comparable non-dimensional kick amplitudes, but kick frequency in humans was greater than for cetaceans swimming at equivalent speeds. Human swimmers required up to five kicks per body length traveled, while cetaceans require only 1.3. Length-specific velocities reached a maximum of 0.81 for humans and this was about half that of cetaceans. Human swimmers had a mean Strouhal number of 0.80, which was above the range considered optimal for underwater undulatory propulsion.     

Ergebnisse der Katathymimaginativen Psychotherapie

The goal of this study was to examine the effect of guided affective imagery therapy in an outpatient setting.At first, 140 patients were recruited.Unfortunately, there were many drop-outs at the beginning of the study as well as at later assessments.The data of 66 patients could be evaluated.The patients were assessed at the beginning of the therapy, after 25 sessions, at the end of the therapy and 18 month after the end of the therapy. Because of too many drop-outs, the originally planned waiting-control-design was realized only to some extent.The diagnoses of the patients consisted mainly of neurotic disorders,many of them with a dysthymia. Data were gathered by standardized questionnaires. There were marked effects of the therapies at the end of the treatments and also at the follow-up evaluation.Effect sizes were larger than 0.8 in somatic symptoms, mood, depression and life satisfaction.On the one hand, therefore, these therapies had been very effective. On the other hand, it became obvious during the course of the study, how difficult it is to conduct such a design with many therapists in a private practice and without financial support.     

How many hindsight biases are there?

The answer is three: questioning a conceptual default assumption in hindsight bias research, we argue that the hindsight bias is not a unitary phenomenon but consists of three separable and partially independent subphenomena or components, namely, memory distortions, impressions of foreseeability and impressions of necessity. Following a detailed conceptual analysis including a systematic survey of hindsight characterizations in the published literature, we investigated these hindsight components in the context of political elections. We present evidence from three empirical studies that impressions of foreseeability and memory distortions (1) show hindsight effects that typically differ in magnitude and sometimes even in direction, (2) are essentially uncorrelated, and (3) are differentially influenced by extraneous variables. A fourth study found similar dissociations between memory distortions and impressions of necessity. All four studies thus provide support for a separate components view of the hindsight bias. An important consequence of such a view is that apparent contradictions in research findings as well as in theoretical explanations (e.g., cognitive vs. social-motivational) might be alleviated by taking differences between components into account. We also suggest conditions under which the components diverge or converge.     

Finding groups using model-based cluster analysis: heterogeneous emotional self-regulatory processes and heavy alcohol use risk

Model-based cluster analysis is a new clustering procedure to investigate population heterogeneity utilizing finite mixture multivariate normal densities. It is an inferentially based, statistically principled procedure that allows comparison of nonnested models using the Bayesian information criterion to compare multiple models and identify the optimum number of clusters. The current study clustered 36 young men and women on the basis of their baseline heart rate and heart rate variability (HRV), chronic alcohol use, and reasons for drinking. Two cluster groups were identified and labeled the high alcohol risk and normative groups. Compared to the normative group, individuals in the high alcohol risk group had higher levels of alcohol use and more strongly endorsed disinhibition and suppression reasons for use. The high alcohol risk group showed significant HRV changes in response to positive and negative emotional and appetitive picture cues, compared to neutral cues. In contrast, the normative group showed a significant HRV change only to negative cues. Findings suggest that individuals with autonomic self-regulatory difficulties may be more susceptible to heavy alcohol use and use of alcohol for emotional regulation.     

Inclusion-exclusion of positive and negative past selves: mood congruence as information

The current research challenges the widespread truism that recalling a positive self necessarily increases self-esteem, whereas recalling a negative self necessarily decreases self-esteem. Four experiments demonstrate that chronically happy people show a relative increase in self-esteem by recalling either a positive or a negative self. Chronically sad people, however, show a relative decrease in self-esteem by recalling either a positive or a negative self. These effects are due to divergent perceptions of mood congruence between the recalled self and the current self. Specifically, happy people perceive high mood congruence between a recalled positive self and the current self but low mood congruence between a recalled negative self and the current self. In contrast, sad people perceive high mood congruence between a recalled negative self and the current self but low mood congruence between a recalled positive self and the current self. Independent of chronic mood, mood congruence leads to perceptions of temporal recency, whereas mood incongruence leads to perceptions of temporal distance. In line with the inclusion-exclusion model of social judgment, perceived temporal recency elicits assimilation effects on self-esteem, whereas perceived temporal distance elicits contrast effects on self-esteem.     

The Association Between Childhood Gender Atypical Behavior and Adult Psychiatric Symptoms is Moderated by Parenting Style

The association between childhood gender atypical behavior (GAB) i.e. behavior traditionally considered more typical for children of the opposite sex, and adult psychiatric symptoms as well as cold or over-controlling parenting style as a moderator of the association were studied in a sample of 1767 Finnish participants aged 33 to 43 years (M?=?37.5). Participants completed the Gender Identity/Gender Role Questionnaire, the Brief Symptom Inventory 18, and the Measure of Parenting Style. Regression analyses showed that women recalled more GAB than men did, and that participants who recalled more GAB reported significantly more psychiatric symptoms. Negative parenting style was associated with psychiatric symptoms. Structural equation modeling showed that parenting style significantly moderated the association between childhood GAB and adult psychiatric symptoms with positive parenting reducing the association and negative parenting sustaining it.     

Minds, persons, and space: an fMRI investigation into the relational complexity of higher-order intentionality

Mental state reasoning or theory-of-mind has been the subject of a rich body of imaging research. Although such investigations routinely tap a common set of regions, the precise function of each area remains a contentious matter. With the help of functional magnetic resonance imaging (fMRI), we sought to determine which areas are involved when processing mental state or intentional metarepresentations by focusing on the relational aspect of such representations. Using non-intentional relational representations such as spatial relations between persons and between objects as a contrast, the results ascertained the involvement of the precuneus, the temporal poles, and the medial prefrontal cortex in the processing of intentional representations. In contrast, the anterior superior temporal sulcus and the left temporo-parietal junction were implicated when processing representations that refer to the presence of persons in relational contexts in general. The right temporo-parietal junction, however, was specifically activated for persons entering spatial relations. The level of representational complexity, a previously unexplored factor, was also found to modulate the neural response in some brain regions, such as the medial prefrontal cortex and the right temporo-parietal junction. These findings highlight the need to take into account the critical roles played by an extensive network of neural regions during mental state reasoning.     

Circulating fibrinogen but not D-dimer level is associated with vital exhaustion in school teachers

Meta-analyses have established elevated fibrinogen and D-dimer levels in the circulation as biological risk factors for the development and progression of coronary artery disease (CAD). Here, we investigated whether vital exhaustion (VE), a known psychosocial risk factor for CAD, is associated with fibrinogen and D-dimer levels in a sample of apparently healthy school teachers. The teaching profession has been proposed as a potentially high stressful occupation due to enhanced psychosocial stress at the workplace. Plasma fibrinogen and D-dimer levels were measured in 150 middle-aged male and female teachers derived from the first year of the Trier-Teacher-Stress-Study. Log-transformed levels were analyzed using linear regression. Results yielded a significant association between VE and fibrinogen (p = 0.02) but not D-dimer controlling for relevant covariates. Further investigation of possible interaction effects resulted in a significant association between fibrinogen and the interaction term "VE x gender" (p = 0.05). In a secondary analysis, we reran linear regression models for males and females separately. Gender-specific results revealed that the association between fibrinogen and VE remained significant in males but not females. In sum, the present data support the notion that fibrinogen levels are positively related to VE. Elevated fibrinogen might be one biological pathway by which chronic work stress may impact on teachers' cardiovascular health in the long run.