120 resultados para mating choice


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As far as healthy food is concerned, it cannot be categorized simply as "good" or "bad" since its effect on health depends mainly on the amount and method consumed. Today's recommendations include a diversified diet, a diet which targets energy-balance and provides all nutrients necessary. Living in an affluent society aggravates healthy choices because of a constantly available, large assortment of food items. In general, the way food is prepared these days has changed a lot: mainly, the energy content has constantly increased, while the fiber and natural micronutrient concentrations decreased. Food items with a high energy yield, containing a lot of fat and sugar, affects our energy balance, which may lead to diseases of affluence such as type 2 diabetes, cardiovascular diseases, and some kinds of tumors.

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Humans are noted for their capacity to over-ride self-interest in favor of normatively valued goals. We examined the neural circuitry that is causally involved in normative, fairness-related decisions by generating a temporarily diminished capacity for costly normative behavior, a 'deviant' case, through non-invasive brain stimulation (repetitive transcranial magnetic stimulation) and compared normal subjects' functional magnetic resonance imaging signals with those of the deviant subjects. When fairness and economic self-interest were in conflict, normal subjects (who make costly normative decisions at a much higher frequency) displayed significantly higher activity in, and connectivity between, the right dorsolateral prefrontal cortex (DLPFC) and the posterior ventromedial prefrontal cortex (pVMPFC). In contrast, when there was no conflict between fairness and economic self-interest, both types of subjects displayed identical neural patterns and behaved identically. These findings suggest that a parsimonious prefrontal network, the activation of right DLPFC and pVMPFC, and the connectivity between them, facilitates subjects' willingness to incur the cost of normative decisions.

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Individuals differ widely in how steeply they discount future rewards. The sources of these stable individual differences in delay discounting (DD) are largely unknown. One candidate is the COMT Val158Met polymorphism, known to modulate prefrontal dopamine levels and affect DD. To identify possible neural mechanisms by which this polymorphism may contribute to stable individual DD differences, we measured 73 participants' neural baseline activation using resting electroencephalogram (EEG). Such neural baseline activation measures are highly heritable and stable over time, thus an ideal endophenotype candidate to explain how genes may influence behavior via individual differences in neural function. After EEG-recording, participants made a series of incentive-compatible intertemporal choices to determine the steepness of their DD. We found that COMT significantly affected DD and that this effect was mediated by baseline activation level in the left dorsal prefrontal cortex (DPFC): (i) COMT had a significant effect on DD such that the number of Val alleles was positively correlated with steeper DD (higher numbers of Val alleles means greater COMT activity and thus lower dopamine levels). (ii) A whole-brain search identified a cluster in left DPFC where baseline activation was correlated with DD; lower activation was associated with steeper DD. (iii) COMT had a significant effect on the baseline activation level in this left DPFC cluster such that a higher number of Val alleles was associated with lower baseline activation. (iv) The effect of COMT on DD was explained by the mediating effect of neural baseline activation in the left DPFC cluster. Our study thus establishes baseline activation level in left DPFC as salient neural signature in the form of an endophenotype that mediates the link between COMT and DD.

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Disruption of function of left, but not right, lateral prefrontal cortex (LPFC) with low-frequency repetitive transcranial magnetic stimulation (rTMS) increased choices of immediate rewards over larger delayed rewards. rTMS did not change choices involving only delayed rewards or valuation judgments of immediate and delayed rewards, providing causal evidence for a neural lateral-prefrontal cortex-based self-control mechanism in intertemporal choice.

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Switzerland is officially free from bovine Tritrichomonas foetus. While bulls used for artificial insemination (AI) are routinely examined for this pathogen, bulls engaged in natural mating, as well as aborted fetuses, are only very sporadically investigated, indicating that the disease awareness for bovine tritrichomoniasis is low. Natural mating in cattle is becoming increasingly popular in Switzerland. Accordingly, a re-introduction/re-occurrence of T. foetus in cattle seems possible either via resurgence from a yet unknown bovine reservoir, or via importation of infected cattle. The low disease awareness for bovine tritrichomoniasis might favor an unnoticed re-establishment of T. foetus in the Swiss cattle population. The aim of our study was thus to search for the parasite, and if found, to assess the prevalence of bovine T. foetus in Switzerland. We included (1) bulls over two years of age used in natural mating and sent to slaughter, (2) bulls used for natural service in herds with or without fertility problems and (3) aborted fetuses. Furthermore, the routinely examined bulls used for AI (4) were included in this study. In total, 1362 preputial samples from bulls and 60 abomasal fluid samples of aborted fetuses were analyzed for the presence of T. foetus by both in vitro cultivation and molecular analyses. The parasite could not be detected in any of the samples, indicating that the maximal prevalence possibly missed was about 0.3% (95% confidence). Interestingly, in preputial samples of three bulls of category 1, apathogenic Tetratrichomonas sp. was identified, documenting a proof-of-principle for the methodology used in this study.

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Objective: We examined the influence of clinical, radiologic, and echocardiographic characteristics on antithrombotic choice in patients with cryptogenic stroke (CS) and patent foramen ovale (PFO), hypothesizing that features suggestive of paradoxical embolism might lead to greater use of anticoagulation. Methods: The Risk of Paradoxical Embolism Study combined 12 databases to create the largest dataset of patients with CS and known PFO status. We used generalized linear mixed models with a random effect of component study to explore whether anticoagulation was preferentially selected based on the following: (1) younger age and absence of vascular risk factors, (2) “high-risk” echocardiographic features, and (3) neuroradiologic findings. Results: A total of 1,132 patients with CS and PFO treated with anticoagulation or antiplatelets were included. Overall, 438 participants (39%) were treated with anticoagulation with a range (by database) of 22% to 54%. Treatment choice was not influenced by age or vascular risk factors. However, neuroradiologic findings (superficial or multiple infarcts) and high-risk echocardiographic features (large shunts, shunt at rest, and septal hypermobility) were predictors of anticoagulation use. Conclusion: Both antithrombotic regimens are widely used for secondary stroke prevention in patients with CS and PFO. Radiologic and echocardiographic features were strongly associated with treatment choice, whereas conventional vascular risk factors were not. Prior observational studies are likely to be biased by confounding by indication.

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We introduce a version of operational set theory, OST−, without a choice operation, which has a machinery for Δ0Δ0 separation based on truth functions and the separation operator, and a new kind of applicative set theory, so-called weak explicit set theory WEST, based on Gödel operations. We show that both the theories and Kripke–Platek set theory KPKP with infinity are pairwise Π1Π1 equivalent. We also show analogous assertions for subtheories with ∈-induction restricted in various ways and for supertheories extended by powerset, beta, limit and Mahlo operations. Whereas the upper bound is given by a refinement of inductive definition in KPKP, the lower bound is by a combination, in a specific way, of realisability, (intuitionistic) forcing and negative interpretations. Thus, despite interpretability between classical theories, we make “a detour via intuitionistic theories”. The combined interpretation, seen as a model construction in the sense of Visser's miniature model theory, is a new way of construction for classical theories and could be said the third kind of model construction ever used which is non-trivial on the logical connective level, after generic extension à la Cohen and Krivine's classical realisability model.

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External circumstances and internal bodily states often change and require organisms to flexibly adapt valuation processes to select the optimal action in a given context. Here, we investigate the neurobiology of context-dependent valuation in 22 human subjects using functional magnetic resonance imaging. Subjects made binary choices between visual stimuli with three attributes (shape, color, and pattern) that were associated with monetary values. Context changes required subjects to deviate from the default shape valuation and to integrate a second attribute in order to comply with the goal to maximize rewards. Critically, this binary choice task did not involve any conflict between opposing monetary, temporal, or social preferences. We tested the hypothesis that interactions between regions of dorsolateral and ventromedial prefrontal cortex (dlPFC; vmPFC) implicated in self-control choices would also underlie the more general function of context-dependent valuation. Consistent with this idea, we found that the degree to which stimulus attributes were reflected in vmPFC activity varied as a function of context. In addition, activity in dlPFC increased when context changes required a reweighting of stimulus attribute values. Moreover, the strength of the functional connectivity between dlPFC and vmPFC was associated with the degree of context-specific attribute valuation in vmPFC at the time of choice. Our findings suggest that functional interactions between dlPFC and vmPFC are a key aspect of context-dependent valuation and that the role of this network during choices that require self-control to adjudicate between competing outcome preferences is a specific application of this more general neural mechanism.

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Developing career-choice readiness is an important task in adolescence, but current theory and research has provided a rather static view of the phenomenon. The present study investigated the development of career-choice readiness among a group of 325 Swiss students assessed four times every 5 months from seventh through eighth grade. A variable-centered approach applying latent curve modeling showed not only a linear increase of readiness over time but also significant inter-individual differences in the level and development of readiness. Higher levels were predicted by more self-esteem and generalized self-efficacy and fewer perceived barriers while increase in readiness was predicted by increase in occupational information. A person-centered approach applying latent class-growth analysis identified four distinct developmental trajectories: high-increasing (42%), high-decreasing (5%), moderate-increasing (42%), and constantly low (11%). Students with different trajectories showed significant differences in core self-evaluations, occupational knowledge, and barriers. The results suggest that environmental demands promote a developmental trend in readiness development that overrules individual differences for the majority of students. Individual differences affect the level of readiness to a greater extent than the process of its development. Career information seems pivotal for readiness increase.

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This longitudinal panel study investigated predictors and outcomes of active engagement in career preparation among 349 Swiss adolescents from the beginning to the end of eighth grade. Latent variable structural equation modeling was applied. The results showed that engagement in terms of self- and environmental-exploration and active career planning related positively to interindividual increases in career decidedness and choice congruence. More perceived social support, early goal decidedness, and particular personality traits predicted more engagement. Support and personality impacted outcomes only mediated through engagement. Early decidedness and congruence were significant predictors of their respective later levels. Implications for practice are presented.

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Our contribution analyses the influence of campaign advertisements on vote choice in the 2011 elections to the Swiss National Council. Concretely, we ask whether and to what extent the relative exposure to party ads of a preferred party exerts a reinforcing effect on an individual's party choice. We make use of the two-wave panel structure contained in the RCS survey data of the Selects 2011 and combine it with data on advertisements in 20 important national and regional newspapers. We find that increasing exposure to the campaign of one's preferred party may reinforce individuals with strong party attachment in their initial vote choice. Yet this effect only materializes with substantial campaign duration and exposure. Additional and exploratory analyses revealed that particularly the two recently emerged parties, the GLP and BDP, might have made a slight difference by potentially persuading defecting voters with the help of their campaign.

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A frequent applied method in career assessment to elicit clients’ self-concepts is asking them to predict their interest assessment results. Accuracy in estimating one’s interesttype is commonly taken as a sign of more self-awareness and career choice readiness. The study evaluated the empirical relation of accuracy of self-estimation to career choice readiness within a sample of 350 Swiss secondary students in seventh grade. Overall, accuracy showed only weak relations to career choice readiness. However, accurately estimating one’s first interest-type in a three-letter RIASEC interests-code emerged as a sign of more vocational identity and total career choice readiness. Accuracy also correlated positively with interest profile consistency, differentiation, and congruence to career aspirations. Implications of the results for career counseling and assessment practice are presented.