377 research outputs found
A longitudinal study of dominance and aggression in greylag geese (Anser anser)
A variety of factors are known to affect dominance and aggression in social vertebrates. In the present study, we used a long-term data set on greylag geese (Anser anser) to investigate the complex relationships between individual life histories, the social environment, and dominance-related behaviors. We applied a multifactorial approach to assess the relative importance of factors in different life-history stages. Previous studies in geese documented effects of sex and social status and achieved differing results for the effects of family size, age, and body weight on dominance and aggression. Extrinsic factors like season or flock structure were generally not considered. Our analyses showed that a considerable number of factors related to individual life histories, season, and the social environment affected dominance and aggression in greylag geese, but not all significant effects were necessarily strong effects. Pronounced effects on aggression rates were caused by the flock's sex ratio, parental effects, individual social status, and sex. Whether individuals interacted with the same opponents repeatedly was influenced most by parental effects and the sex ratio, whereas the strongest determinants of dominance rank were parental effects and social status. Hence, dominance behaviors may not only be influenced by intrinsic factors but also by season and an individual's social environment. Furthermore, our study indicates that optimal choices for achieving or maintaining a high dominance rank may vary considerably between life-history stages. This highlights the value of long-term studies and multifactorial approaches for understanding the complexities of dominance relationships in social vertebrate
Problematic mobile phone use of Swiss adolescents : is it linked with mental health or behaviour?
To investigate the associations between problematic mobile phone use and mental health and behavioural problems in 412 Swiss adolescents owning a mobile phone while controlling for amount of mobile phone use.; Problematic mobile phone use was determined by the MPPUS-10 (Mobile Phone Problem Use Scale) and related to health and behavioural problems by means of multivariable regression modelling.; MPPUS-10 was 4.7 (95 % CI 1.8, 7.6) units higher in girls than in boys, increased significantly with age and was significantly decreased with increasing educational level of the parents. Furthermore, problematic mobile phone use was associated with impaired psychological well-being, impaired parent and school relationships and more behavioural problems but was not related to peer support and social acceptance.; Our study indicates that problematic mobile phone use is associated with external factors such as worse home and school environment and internal factors such as impaired mental health and behavioural problems of the adolescents and thus problematic mobile phone use should be addressed, in particular when dealing with adolescents showing behavioural or emotional problems
A behavioural syndrome, but less evidence for a relationship with cognitive traits in a spatial orientation context
Final LMMs with significant confounding factors on personality and cognitive traits in harvest mice. Table S2. Between-individual correlations among personality and cognitive traits (spatial recognition and spatial learning performance) in harvest mice, calculated from a multivariate mixed model. Table S3. Within-individual correlations between personality and cognitive traits (spatial recognition and spatial learning performance) in harvest mice, calculated from a multivariate mixed model. Table S4. Test for a cognitive syndrome caused by a speed-accuracy trade-off in harvest mice: Between-individual correlations among personality traits and decision styles (decision speed and accuracy) calculated from a multivariate mixed model. Table S5. Test for a cognitive syndrome caused by a speed-accuracy trade-off in harvest mice: Within-individual correlations between personality traits and decision styles (decision speed and accuracy) calculated from a multivariate mixed model. (PDF 324Â kb
Sources of individual variation in plasma testosterone levels
The steroid hormone testosterone (T) plays a central role in the regulation of breeding in males, because many physiological, morphological and behavioural traits related to reproduction are T dependent. Moreover, in many seasonally breeding vertebrates, male plasma T levels typically show a pronounced peak during the breeding season. While such population-level patterns are fairly well worked out, the sources and the implications of the large variability in individual T levels within the seasonal cycle remain surprisingly little understood. Understanding the potential sources of individual variation in T levels is important for behavioural and evolutionary ecologists, for at least two reasons. First, in ‘honest signalling’ theory, T is hypothesized to play a critical role as the assumed factor that enforces honesty of the expression of sexually selected quality indicators. Second, T is often considered a key mediator of central life-history trade-offs, such as investment in survival versus reproduction or in mating versus parental care. Here, we discuss the patterns of within- and between-individual variation in male plasma T levels in free-living populations of birds. We argue that it is unclear whether this variability mainly reflects differences in underlying individual quality (intrinsic factors such as genetic or maternal effects) or in the environment (extrinsic factors including time of day, individual territorial status and past experience). Research in avian behavioural endocrinology has mainly focused on the effects of extrinsic factors, while other sources of variance are often ignored. We suggest that studies that use an integrative approach and investigate the relative importance of all potential sources of variation are essential for the interpretation of data on individual plasma T levels
Cardiotrophin-1 Induces Tumor Necrosis Factor α Synthesis in Human Peripheral Blood Mononuclear Cells
Chronic heart failure (CHF) is associated with elevated concentrations of tumor necrosis factor (TNF) α and cardiotrophin-1 (CT-1) and altered peripheral blood mononuclear cell (PBMC) function. Therefore, we tested whether CT-1 induces TNFα in PBMC of healthy volunteers.
CT-1 induced in PBMC TNFα protein in the supernatant and TNFα mRNA in a concentration- and time-dependent manner determined by ELISA and real-time PCR, respectively. Maximal TNFα protein was achieved with 100 ng/mL CT-1 after 3–6 hours and maximal TNFα mRNA induction after 1 hour. ELISA data were confirmed using immunofluorescent flow cytometry. Inhibitor studies with actinomycin D and brefeldin A showed that both protein synthesis and intracellular transport are essential for CT-1 induced TNFα expression. CT-1 caused a dose dependent nuclear factor (NF) κB translocation. Parthenolide inhibited both NFκB translocation and TNFα protein expression indicating that NFκB seems to be necessary.
We revealed a new mechanism for elevated serum TNFα concentrations and PBMC activation in CHF besides the hypothesis of PBMC activation by bacterial translocation from the gut
Clinical examination and patients’ history are not suitable for neonatal hip screening
PURPOSE: To assess the percentage of missed developmental dysplasia of the hip, which escape the German criteria for newborn hip high-risk screening, we analyzed our data gained from the general neonatal sonographic hip screening performed at our department. The aim of the study was to determine the number of potentially belatedly treated developmental dysplasia of the hip. METHODS: The data from 1145 standardized newborn hip ultrasound examinations according to the Graf technique were analyzed retrospectively comparing findings for general neonatal sonographic hip screening and high-risk screening subgroups. RESULTS: We diagnosed developmental dysplasia of the hip in 18 of the 1145 newborns via ultrasound. A total of 10 out of 18 developmental dysplasia of the hip would have been missed by high-risk screening, which corresponds to a proportion of 55.6% false-negative results. The sensitivity of high-risk screening was only 44.4% and specificity, 78.3%. The positive predictive value was 3.2%. Family history as a screening criterion yielded false-negative results in 77.8% and false-positive results in 16.8%. In all, 83.3% of the children who were born with developmental dysplasia of the hip but not from breech position as a risk factor were false negative. The clinical examination was false negative in 88.9% and false positive in 0.6%. CONCLUSION: High-risk screening detected less than every second developmental dysplasia of the hip, rendering the first month as the most effective treatment window unavailable for inapparent dysplastic hips, potentially resulting in the need for more invasive treatment. Due to the high sensitivity of ultrasound in the detection of developmental dysplasia of the hip, we recommend to replace the current German high-risk screening guidelines with a general newborn screening for all neonates using Graf ultrasound in the first week of life. LEVEL OF EVIDENCE: Level II
A multivariate analysis of genetic constraints to life history evolution in a wild population of red deer.
Evolutionary theory predicts that genetic constraints should be widespread, but empirical support for their existence is surprisingly rare. Commonly applied univariate and bivariate approaches to detecting genetic constraints can underestimate their prevalence, with important aspects potentially tractable only within a multivariate framework. However, multivariate genetic analyses of data from natural populations are challenging because of modest sample sizes, incomplete pedigrees, and missing data. Here we present results from a study of a comprehensive set of life history traits (juvenile survival, age at first breeding, annual fecundity, and longevity) for both males and females in a wild, pedigreed, population of red deer (Cervus elaphus). We use factor analytic modeling of the genetic variance-covariance matrix ( G: ) to reduce the dimensionality of the problem and take a multivariate approach to estimating genetic constraints. We consider a range of metrics designed to assess the effect of G: on the deflection of a predicted response to selection away from the direction of fastest adaptation and on the evolvability of the traits. We found limited support for genetic constraint through genetic covariances between traits, both within sex and between sexes. We discuss these results with respect to other recent findings and to the problems of estimating these parameters for natural populations
Taking shortcuts: Cognitive conflict during motivated rule-breaking
Deliberate rule violations have typically been addressed from a motivational perspective that
asked whether or not agents decide to violate rules based on contextual factors and moral considerations.
Here we complement motivational approaches by providing a cognitive perspective
on the processes that operate during the act of committing an unsolicited rule violation.
Participants were tested in a task that allowed for violating traffic rules by exploiting forbidden
shortcuts in a virtual city maze. Results yielded evidence for sustained cognitive conflict that
affected performance from right before a violation throughout actually committing the violation.
These findings open up a new theoretical perspective on violation behavior that focuses on
processes occurring right at the moment a rule violation takes place
Taking shortcuts: Cognitive conflict during motivated rule-breaking
Deliberate rule violations have typically been addressed from a motivational perspective that
asked whether or not agents decide to violate rules based on contextual factors and moral considerations.
Here we complement motivational approaches by providing a cognitive perspective
on the processes that operate during the act of committing an unsolicited rule violation.
Participants were tested in a task that allowed for violating traffic rules by exploiting forbidden
shortcuts in a virtual city maze. Results yielded evidence for sustained cognitive conflict that
affected performance from right before a violation throughout actually committing the violation.
These findings open up a new theoretical perspective on violation behavior that focuses on
processes occurring right at the moment a rule violation takes place
The influence of fractionated radiotherapy on the stability of spinal bone metastases: a retrospective analysis from 1047 cases
Background: The effect of radiotherapy, in particular the application of different multi-fraction schedules in the management of unstable spinal bone metastases (SBM), is incompletely understood. This study aims to compare the radiological response regarding various dose and fractionation schedules of radiotherapy in the palliative treatment of SBM.
Methods: We retrospectively assessed 1047 patients with osteolytic SBM, treated with palliative radiotherapy at our department between 2000 and 2015. Lung cancer (40.2%), breast (16.7%) and renal cancer (15.2%) were the most common solid tumors in this study. Different common multi-fraction regimen (5x4Gy, 10x3Gy, 14 × 2.5Gy and 20x2Gy) were compared with regard to radiological response and recalcification at 3 and 6 months after radiotherapy. The Taneichi score was used for classification of osteolytic SBM.
Results: Median follow up was 6.3 months. The median overall survival (OS) in the short-course radiotherapy (SCR) group using less than 10 treatment fractions was 5.5 months vs. 9.5 months in the long-course radiotherapy (LCR) group using in excess of 10 fractions (log rank p < .0001). Overall survival (OS) in the SCR group after 3 and 6 months was 66.8 and 49.1%, respectively vs 80.9 and 61.5%, respectively in the LCR group. 17.6% (n = 54/306) and 31.1% (n = 89/286) of unstable SBM were classified as stable in the SCR group at 3 and 6 months post radiotherapy, respectively (p < .001 for both). In the LCR group, 24.1% (n = 28/116) and 34.2% (n = 38/111) of unstable SBM were stabilized after 3 and 6 months, respectively (p < .001 for both).
Conclusions: Our study shows no significant difference in stabilization achieving recalcification rates between multi-fraction schedules (SCR vs. LCR) in the palliative management of unstable SBM. Both groups with multi-fraction regimen demonstrate a stabilizing effect following 3 and 6 months after radiotherapy
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