Recent evidence in natural and semi-natural settings has revealed a variety of left-right perceptual asymmetries among vertebrates. These include preferential use of the left or right visual ...hemifield during activities such as searching for food, agonistic responses, or escape from predators in animals as different as fish, amphibians, reptiles, birds, and mammals. There are obvious disadvantages in showing such directional asymmetries because relevant stimuli may be located to the animal's left or right at random; there is no a priori association between the meaning of a stimulus (e.g., its being a predator or a food item) and its being located to the animal's left or right. Moreover, other organisms (e.g., predators) could exploit the predictability of behavior that arises from population-level lateral biases. It might be argued that lateralization of function enhances cognitive capacity and efficiency of the brain, thus counteracting the ecological disadvantages of lateral biases in behavior. However, such an increase in brain efficiency could be obtained by each individual being lateralized without any need to align the direction of the asymmetry in the majority of the individuals of the population. Here we argue that the alignment of the direction of behavioral asymmetries at the population level arises as an "evolutionarily stable strategy" under "social" pressures occurring when individually asymmetrical organisms must coordinate their behavior with the behavior of other asymmetrical organisms of the same or different species.
The aim of this study is to evaluate orbital symmetry in goat and sheep skulls. For this purpose, a total of 83 skulls, including 50 sheep and 33 goat skulls, were used in the study. Geometric ...morphometry method was applied. For symmetric analysis, one side of each orbit was photographed twice and mirror images were created. There were 36 landmards marked to determine the outer limit of the orbita. As a result of the study, asymmetric components (fluctuating asymmetry and directional asymmetry) for shape were statistically significant in both goats and sheep (p < 0.0001). The first three principal components explained 52.558% of the total shape variation in goats and 61.245% in sheep. This value for symmetric components was 59.095% and 67.742% for goats and sheep, respectively, and 66.791% and 71.154% for asymmetric components. As a result of discriminant function analysis, right and left orbital shapes showed grouping characteristics with similar success rates according to species. Although limited, the right orbit in goats (100%) and the left orbit in sheep (96.5%) were grouped more accurately.
Because of high information asymmetry, in the days before earnings announcements, stock trading is decreased. After checking it was found that the decrease in trading is asymmetric (imbalancing) and ...the decrease in purchases of shares in these days is more than of the sales decline the decision of traders to sell will lead to positive returns after the earnings announcement. Among the factors affecting the selling of shares, is increasing the cost of transactions. The contribution of this study was to define the new assumptions and investigating of profitability news and return variables in the form of simultaneous equations, that it was not any other reason. After reviewing data from 147 firms in Tehran Stock Exchange during the period of 2009-2014 was marked that profit news, investor attention and sell pressure variables have direct affect on return variable. As well as the relationship between investor attention and returns variables with profit news is direct, but the impact of selling pressure on profitability news is reversed.
The conventional assumption in human cognitive electrophysiology using EEG and MEG is that the presentation of a particular event such as visual or auditory stimuli evokes a "turning on" of ...additional brain activity that adds to the ongoing background activity. Averaging multiple event-locked trials is thought to result in the cancellation of the seemingly random phased ongoing activity while leaving the evoked response. However, recent work strongly challenges this conventional view and demonstrates that the ongoing activity is not averaged out due to specific non-sinusoidal properties. As a consquence, systematic modulations in ongoing activity can produce slow cortical evoked responses reflecting cognitive processing. In this review we introduce the concept of "rhythmic pulsing" to account for this specific non-sinusoidal property. We will explain how rhythmic pulsing can create slow evoked responses from a physiological perspective. We will also discuss how the notion of rhythmic pulsing provides a unifying framework linking ongoing oscillations, evoked responses and the brain's capacity to process incoming information.
The global level of hierarchical stimuli (Navon's stimuli) is typically processed quicker and better than the local level; further differential hemispheric dominance is described for local (left ...hemisphere, LH) and global (right hemisphere, RH) processing. However, neuroimaging and behavioral data indicate that stimulus category (letter or object) could modulate the hemispheric asymmetry for the local level processing. Besides, when the targets are unpredictably displayed at the global or local level, the participant has to switch between levels, and the magnitude of the switch cost increases with the number of repeated-level trials preceding the switch. The hemispheric asymmetries associated with level switching is an unresolved issue. LH areas may be involved in carrying over the target level information in case of level repetition. These areas may also largely participate in the processing of level-changed trials. Here we hypothesized that RH areas underly the inhibitory mechanism performed on the irrelevant level, as one of the components of the level switching process. In an experiment using a within-subject design, hierarchical stimuli were briefly presented either to the right or to the left visual field. 32 adults were instructed to identify the target at the global or local level. We assessed a possible RH dominance for the non-target level inhibition by varying the attentional demands through the manipulation of level repetitions (two or gour repeated-level trials before the switch). The behavioral data confirmed a LH specialization only for the local level processing of letter-based stimuli, and detrimental effect of increased level repetitions before a switch. Further, data provides evidence for a RH advantage in inhibiting the non-target level. Taken together, the data supports the notion of the existence of multiple mechanisms underlying level-switch effects.
Detailed time-series of the resultant joint moments and segmental interactions during soccer instep kicking were compared between the preferred and non-preferred kicking leg. The kicking motions of ...both legs were captured for five highly skilled players using a three-dimensional cinematographic technique at 200 Hz. The resultant joint moment (muscle moment) and moment due to segmental interactions (interaction moment) were computed using a two-link kinetic chain model composed of the thigh and lower leg (including shank and foot). The mechanical functioning of the muscle and interaction moments during kicking were clearly illustrated. Significantly greater ball velocity (32.1 vs. 27.1 m · s
−1
), shank angular velocity (39.4 vs. 31.8 rad · s
−1
) and final foot velocity (22.7 vs. 19.6 m · s
−1
) were observed for the preferred leg. The preferred leg showed a significantly greater knee muscle moment (129.9 N · m) than the non-preferred leg (93.5 N · m), while no substantial differences were found for the interaction moment between the two legs (79.3 vs. 55.7 N · m). These results indicate that the highly skilled soccer players achieved a well-coordinated inter-segmental motion for both the preferred and non-preferred leg. The faster leg swing observed for the preferred leg was most likely the result of the larger muscle moment.
Out of The Books: Field Philosophy Despret, Vinciane
Parallax (Leeds, England),
10/2018, Volume:
24, Issue:
4
Journal Article, Web Resource
Peer reviewed
Open access
Many philosophers, from Socrates to William James or Leibniz, have conducted inquiries and constituted what is now called in social sciences, "fields". How can we inherit from them? And what is our ...specificity, as philosophers, in relation to the practices of the human and social sciences? Based on a field experience that questioned the usual routines of the inquiry, and in particular the practice of anonymity, this article proposes to think about how these routines have some effects both on the people surveyed, and on the knowledge produced with or upon them. This gesture of questioning the practices which forces us to adopt other ways of addressing the situation leads the philosopher inquirer to consider his investigation as a real experiment, and thus it subjects the inquirer to the obligation to think of inquiry as a creative practice. On analysis, one realizes that it is not however proper to the philosophical inquiry, but that it is the essential dimension of any them, be that the scientist explicitly claims it or that she tries on the contrary to minimize to make her inquiry a copy of the reality she claims to reveal.
Microfinance, the provision of small individual and business loans, has experienced dramatic growth, reaching over 150 million borrowers worldwide. Much of the success of microfinance has been ...attributed to attempts to overcome the challenges of information asymmetries in uncollateralized lending. However, very little is known about the optimal contract structure of these loans, and there is substantial variation across lenders, even within a particular setting. This paper exploits a plausibly exogenous change in the liability structure offered by a microfinance program in India, which shifted from individual to group liability lending. We find evidence that the lending model matters: for the same borrower, the required monthly loan installments are 11 percent less likely to be missed under the group liability setting in comparison with individual liability. In addition, compulsory savings deposits are 20 percent less likely to be missed under group liability contracts.
Les tâches quotidiennes exercées par les sapeurs-pompiers (SP) peuvent induire d’importantes contraintes musculo-squelettiques, des risques cardiovasculaires, du burnout et des blessures. L’objectif ...de ce travail doctoral est de caractériser la blessure des SP français et d’analyser l’influence de la pratique d’activité physique AP), du burnout, des stratégies de coping, des traits de personnalité, et des buts d’accomplissement dans l’occurrence des blessures. Nous défendons la thèse selon laquelle la blessure des SP français serait expliquée à la fois par des facteurs psychologiques et physiologiques. Au travers de quatre études expérimentales, les principaux résultats obtenus indiquent que l’entorse de la cheville est la blessure majeure dans cette population. Même si les missions des SP sont dangereuses et variées, les blessures surviennent paradoxalement au cours des heures de pratique de l’AP pendant les jours de garde. De plus, le nombre d’heures d’AP total pratiqué par semaine est associé aux blessures. Nous observons également que les performances réalisées au Y-balance test, au « weight bearing lunge test » sont prédictives de l’entorse de la cheville. Même si nos investigations permettent de mettre en évidence que la blessure est à la fois causée par des facteurs psychologiques (e.g., burnout) et physiologiques, la pratique de l’AP, obligatoire et nécessaire chez les SP, demeure paradoxalement le plus grand pourvoyeur d’accident de travail
Daily tasks of firefighters may induce significant musculoskeletal constraints, cardiovascular risks, burnout and injuries. The aim of this doctoral work was to characterize the specific injuries of French firefighters, and to analyze influence of physical activity (PA), burnout, coping strategies, personality traits, and achievement goal in this injury occurrence. We hypothesize that injuries of French firefighters would be explained by both psychological and physiological factors. Through four experimental studies, the main results indicate that ankle sprain is the major injury in this population. Although SP missions are dangerous and varied, paradoxically injuries occur during the hours of PA practice in day guard. In addition, the total number of hours AP practiced per week is associated with injury. We also observed that the performances achieved in the Y-balance test, the "weight bearing lunge test" are predictive of ankle sprains. Although our investigations have highlighted that the injury was caused by psychological (e.g., burnout) and physiological factors, practicing sessions of AP is compulsory and required in this job, and paradoxically remains the largest provider of occupational incident
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