Limb Preference in Animals: New Insights into the Evolution of Manual Laterality in Hominids

Until the 1990s, the notion of brain lateralization—the division of labor between the two hemispheres—and its more visible behavioral manifestation, handedness, remained fiercely defined as a human specific trait. Since then, many studies have evidenced lateralized functions in a wide range of species, including both vertebrates and invertebrates. In this review, we highlight the great contribution of comparative research to the understanding of human handedness’ evolutionary and developmental pathways, by distinguishing animal forelimb asymmetries for functionally different actions—i.e., potentially depending on different hemispheric specializations. Firstly, lateralization for the manipulation of inanimate objects has been associated with genetic and ontogenetic factors, with specific brain regions’ activity, and with morphological limb specializations. These could have emerged under selective pressures notably related to the animal locomotion and social styles. Secondly, lateralization for actions directed to living targets (to self or conspecifics) seems to be in relationship with the brain lateralization for emotion processing. Thirdly, findings on primates’ hand preferences for communicative gestures accounts for a link between gestural laterality and a left-hemispheric specialization for intentional communication and language. Throughout this review, we highlight the value of functional neuroimaging and developmental approaches to shed light on the mechanisms underlying human handedness.

Perceiver Effects in First Impressions Reflect Generalized Stereotypes: Evidence of Consistency Across Time, Groups, and Contexts

In interpersonal perception, perceivers’ tendencies for judging the average target (perceiver effects) are commonly assumed to reflect generalized stereotypes about “the other.” This is empirically supported by findings of consistent rank-orders of perceiver effects across measurement occasions, but previous studies could not rule out important alternative explanations for consistency. Here, we present a strict test of the generalized stereotype account in two studies ( ns 146 and 295) in which participants provided mutual impressions in distinct, uniquely composed groups. Results reveal that perceiver effects are quite consistent on the level of global evaluation and acquiescence but less consistent on the level of specific trait- or item-content. The finding that perceivers who saw others in globally positive or negative ways in one situation also saw other targets in similar ways in entirely different situations across time, groups, and contexts is strong evidence for the generalized stereotype account and has vital implications.

The Effect of Flux Dysconnectivity Functions on Concentration Gradients Changes in a Multicomponent Model of Convectional Reaction-Diffusion by the Example of a Neurovascular Unit

A convectional diffusion of nutrients around the blood vessels in brain occurs in well-structured neurovascular units (NVU) including neurons, glia and micro vessels. A common feature of the process is a combination of a relatively high-speed delivery solution stream inside the blood vessel and a low-speed convectional flow in parenchyma. The specific trait of NVU is the existence of a tight cover layer around the vessels which is formed by shoots (end-feet) of astrocytes. This layer forms so called blood-brain barrier (BBB). Under different pathological states the permeability of BBB is changed. The concentration gradient of a chemical compound in NVU has been modelled using a combination of mathematical description of a cerebral blood flow (CBF) and further 3D diffusion away from the blood vessels borders. The governing equation for the blood flow is the non-steady-state Navier–Stokes equation for an incompressible non-Newtonian fluid flow without buoyancy effects. BBB is modeled by the flux dysconnectivity functions. The velocity of fluid flow in the paravascular space was estimated using Darcy's law. Finally, the diffusion of the nutrient is considered as a convectional reaction-diffusion in a porous media. By the example of glucose, it was shown that increased permeability of BBB yields an increased level of the nutrient even under essential (on 70%) decrease of CBF. Contrarily, a low BBB permeability breeds a decreased concentration level under increased (on 50%) CBF. Such a phenomenon is explained by a smooth enlarge of the direct diffusion area for a blood-to-brain border glucose transport having three-level organization.

Transference of Self Concept in First Impressions of Similar Others

<p>Forming rapid and reasonably accurate impressions of other people to determine the potential for threat is a crucial human skill that has evolved over millennia. That said, often these first impressions may be inaccurate as the processes underlying person perception are subject to bias. Transference is one such bias which occurs when an encountered novel individual, for whatever reason, is similar enough that he or she activates the mental representation of a ‘significant other’ which is then “transferred” to that novel individual. In particular, judgments of the new person are assimilated to both evaluations (positive or negative) as well as the specific trait content of the activated representation. The current research proposed that the self-concept as activated by self-similar stimuli can act in a similar fashion. Specifically, it was proposed that activation of the self-concept – through encountering an individual who is similar to the self – may trigger transference of self-concept-related feelings and emotions to a novel other. The current research tested this prediction in four experiments by comparing participant judgements of own self-concept with trait-related judgements about novel targets, half of which were modified to resemble the perceiver. It was expected that participants would rate participant-similar stimuli as more similar to themselves than non-similar stimuli. Overall, experimental results did not support this hypothesis in that participant judgements and evaluations of self-resembling faces did not differ significantly from judgements and evaluations of stranger-similar faces in any reliable pattern. The implications of these findings are discussed in relation to previous research on first impressions, transference, and self-concept.</p>

Transference of Self Concept in First Impressions of Similar Others

<p>Forming rapid and reasonably accurate impressions of other people to determine the potential for threat is a crucial human skill that has evolved over millennia. That said, often these first impressions may be inaccurate as the processes underlying person perception are subject to bias. Transference is one such bias which occurs when an encountered novel individual, for whatever reason, is similar enough that he or she activates the mental representation of a ‘significant other’ which is then “transferred” to that novel individual. In particular, judgments of the new person are assimilated to both evaluations (positive or negative) as well as the specific trait content of the activated representation. The current research proposed that the self-concept as activated by self-similar stimuli can act in a similar fashion. Specifically, it was proposed that activation of the self-concept – through encountering an individual who is similar to the self – may trigger transference of self-concept-related feelings and emotions to a novel other. The current research tested this prediction in four experiments by comparing participant judgements of own self-concept with trait-related judgements about novel targets, half of which were modified to resemble the perceiver. It was expected that participants would rate participant-similar stimuli as more similar to themselves than non-similar stimuli. Overall, experimental results did not support this hypothesis in that participant judgements and evaluations of self-resembling faces did not differ significantly from judgements and evaluations of stranger-similar faces in any reliable pattern. The implications of these findings are discussed in relation to previous research on first impressions, transference, and self-concept.</p>

The integration of language and society

Language and society are closely integrated and mutually supportive (rather than one being dependant on the other). An unusual (non-universal) facet of a language can relate to a specific trait of social organisation, or life-style, etc., evidenced among the society of language users. On the basis of detailed individual studies, we put forward inductive generalisations concerning recurrent correlations underlying the congruence, or mutual integration, of language and society, and outline dependencies between the established correlations. We identify the following linguistic parameters demonstrably sensitive to societal traits: reference classification: the composition and use of genders and classifiers, types of possession, directing and addressing, information source, transmission of information, interaction patterns, and special speech styles. The focal clusters of the following non-linguistic traits can be shown to be integrated with these linguistic features: A. Relations within a community, social hierarchies, and kinship categorisation; B. Social constraints (taboo and avoidance); C. Principles of interaction and attitudes to information and its sources; D. Beliefs, religion, spirits, and dreams; E. Means of subsistence and physical environment; and F. Language awareness, language engineering, and sensitivity to societal changes. Grammatical categories which show a degree of integration with the society constitute integration points. These may change if social conditions change. A combination of synchronic and diachronic approaches to the integration of language and society brings us a step further towards answering the crucial question: why language are the way they are.

Perceiver effects in first impressions reflect generalized stereotypes: Evidence of consistency across time, groups, and contexts.

In interpersonal perception, perceivers’ tendencies for judging the average target (perceiver effects) are commonly assumed to reflect generalized stereotypes about “the other”. This is empirically supported by findings of consistent rank-orders of perceiver effects across measurement occasions, but previous studies could not rule out important alternative explanations for consistency. Here, we present a strict test of the generalized stereotype account in two studies (ns 146 and 295) in which participants provided mutual impressions in distinct, uniquely composed groups. Results reveal that perceiver effects are quite consistent on the level of global evaluation and acquiescence but less consistent on the level of specific trait- or item-content. The finding that perceivers who saw others in globally positive or negative ways in one situation also saw other targets in similar ways in entirely different situations across time, groups, and contexts is strong evidence for the generalized stereotype account and has vital implications.

Perceiver Effects in Person Perception Reflect Acquiescence, Positivity, and Trait-Specific Content: Evidence From a Large-Scale Replication Study

Person judgments reflect perceiver effects: differences in how perceivers judge the average person. The factorial structure of such effects is still discussed. We present a large-scale, preregistered replication study using over 1 million person judgments (different groups of 200 perceivers judged 200 targets in one of 20 situations, using 30 personality items). Results unanimously favored a model comprising three systematic components: acquiescence (endorsing all items more than other perceivers), positivity (endorsing positive over negative items), and trait specificity (endorsing items reflecting a specific trait more). The latter two factors each accounted for approximately a quarter of the variance in perceiver effects, and acquiescence accounted for less than 10%. Positivity was more influential for evaluative items and was strongly associated with how likable perceivers found their targets to be ( r = .55). With considerable statistical power and generalizability, our findings significantly improve the knowledge base regarding the structure of perceiver effects.

Identification of Clinical Isolates of Candida albicans with Increased Fitness in Colonization of the Murine Gut

The commensal and opportunistic pathogen Candida albicans is an important cause of fungal diseases in humans, with the gastrointestinal tract being an important reservoir for its infections. The study of the mechanisms promoting the C. albicans commensal state has attracted considerable attention over the last few years, and several studies have focused on the identification of the intestinal human mycobiota and the characterization of Candida genes involved in its establishment as a commensal. In this work, we have barcoded 114 clinical C. albicans isolates to identify strains with an enhanced fitness in a murine gastrointestinal commensalism model. The 114 barcoded clinical isolates were pooled in four groups of 28 to 30 strains that were inoculated by gavage in mice previously treated with antibacterial therapy. Eight strains that either exhibited higher colonization load and/or remained in the gut after antibiotic removal were selected. The phenotypic analysis of these strains compared to an RFP-tagged SC5314 wild type strain did not reveal any specific trait associated with its increased colonization; all strains were able to filament and six of the eight strains displayed invasive growth on Spider medium. Analysis of one of these strains, CaORAL3, revealed that although mice required previous bacterial microbiota reduction with antibiotics to be able to be colonized, removal of this procedure could take place the same day (or even before) Candida inoculation. This strain was able to colonize the intestine of mice already colonized with Candida without antibiotic treatment in co-housing experiments. CaORAL3 was also able to be established as a commensal in mice previously colonized by another (CaHG43) or the same (CaORAL3) C. albicans strain. Therefore, we have identified C. albicans isolates that display higher colonization load than the standard strain SC5314 which will surely facilitate the analysis of the factors that regulate fungal colonization.

Phenological, Morphological and Yield based Characterization of Chickpea (Cicer arietinum L.) Germplasm Lines

Background: The characterization of chickpea genetic resources is a vital step to explore genetic variability in breeding programs. In the present study, we characterized 90 germplasm lines of desi chickpea collected across the Indian chickpea growing region. The identified trait-specific germplasm lines will be used as a valuable genetic resource for the chickpea improvement programme. Methods: An experiment was conducted in augmented design to characterize germplasm lines of chickpea for 13 qualitative and 17 quantitative agro-morphological traits under Bundelkhand agro-climatic conditions. Result: Ample variation was observed for qualitative and quantitative traits. The study revealed that the presences of high variability in qualitative and quantitative traits are useful in the identification of plant genotype for a specific trait, genetic purity analysis, germplasm conservation and also possible use of potential genotype in the breeding program.