Contextual blending of ingroup/outgroup face stimuli and word valence: LPP modulation and convergence of measures

<p>Abstract</p> <p>Background</p> <p>Several event related potential (ERP) studies have investigated the time course of different aspects of evaluative processing in social bias research. Various reports suggest that the late positive potential (LPP) is modulated by basic evaluative processes, and some reports suggest that in-/outgroup relative position affects ERP responses. In order to study possible LPP blending between facial race processing and semantic valence (positive or negative words), we recorded ERPs while indigenous and non-indigenous participants who were matched by age and gender performed an implicit association test (IAT). The task involved categorizing faces (ingroup and outgroup) and words (positive and negative). Since our paradigm implies an evaluative task with positive and negative valence association, a frontal distribution of LPPs similar to that found in previous reports was expected. At the same time, we predicted that LPP valence lateralization would be modulated not only by positive/negative associations but also by particular combinations of valence, face stimuli and participant relative position.</p> <p>Results</p> <p>Results showed that, during an IAT, indigenous participants with greater behavioral ingroup bias displayed a frontal LPP that was modulated in terms of complex contextual associations involving ethnic group and valence. The LPP was lateralized to the right for negative valence stimuli and to the left for positive valence stimuli. This valence lateralization was influenced by the combination of valence and membership type relevant to compatibility with prejudice toward a minority. Behavioral data from the IAT and an explicit attitudes questionnaire were used to clarify this finding and showed that ingroup bias plays an important role. Both ingroup favoritism and indigenous/non-indigenous differences were consistently present in the data.</p> <p>Conclusion</p> <p>Our results suggest that frontal LPP is elicited by contextual blending of evaluative judgments of in-/outgroup information and positive vs. negative valence association and confirm recent research relating in-/outgroup ERP modulation and frontal LPP. LPP modulation may cohere with implicit measures of attitudes. The convergence of measures that were observed supports the idea that racial and valence evaluations are strongly influenced by context. This result adds to a growing set of evidence concerning contextual sensitivity of different measures of prejudice.</p

Hematology, Biochemistry and Serum Protein Analyses of Antarctic and non-Antarctic Skuas

Determination of hematological and biochemical parameters provides important data to assess the physiological condition in wild birds. Therefore, to carry out ecophysiology or conservation studies it is essential to establish baseline physiological parameters and how these change with age and life history events. Hematological (hematocrit, hemoglobin and erythrocyte sedimentation) and biochemical (glucose, total lipids and proteins, aspartate and alanine aminotransferase activities and electrolyte concentration) reference values were determined in two Antarctic migratory bird species, the Brown Skua (Stercorarius antarcticus) and South Polar Skua (S. maccormicki), from South Shetland Island during breeding season. Also, hematological data (hematocrit) were determined for non-Antarctic skuas, with Chilean (S. chilensis) and Falkland (S. antarcticus antarcticus) skuas sampled in the Beagle Channel islands (Tierra del Fuego Province) and Viana Island (Chubut Province), Argentina, respectively. Differences between adult Antarctic skua species were observed in hemoglobin, erythrocyte sedimentation, total lipids and aspartate aminotransferase activity. In addition, age-related differences in Antarctic skuas in hematocrit, hemoglobin, glucose and total protein values were observed. Serum reference protein fractions (Albumin, α1, α2, and globulins) were assessed by electrophoresis for Antarctic and non-Antarctic skuas. Similar protein patterns were observed between South Polar and Chilean skuas as well between Falkland Skua and Brown Skua. The differences between adult sympatric Antarctic skuas may be related to their nutritional status and species-specific migrations, feeding habits and the differential use of the breeding niches, while the age variation may be related to physiological development processes in chicks or to the energy expenditure in adults during breeding.Facultad de Ciencias Naturales y Muse

Poor body conditions during the breeding period in a seabird population with low breeding success

Breeding has a high energetic cost and, in central place foragers, also restricts the ability of parents for self-foraging, with afecting on their body and immunological conditions. In migratory species, breeding overlaps the period of recovery of body conditions before the following outbound migration. Those factors may reduce the breeding success and even lead parents to abandon their ofspring if parental body condition cannot guarantee the success of the next migration. We studied the body and immunological conditions of a low breeding success population of Brown Skuas (Stercorarius antarcticus lonnbergi) throughout their breeding season. We evaluated changes in their body mass, blood parameters and heterophil:lymphocyte ratios (H:L), at three stages of their breeding period: Incubation, Early rearing and Late rearing. The body mass of female Brown skuas decreased during the initial stages of the breeding period and recovered towards the end. The changes in metabolites suggest a use of protein body reserves but not of lipid reserves. The H:L ratio did not indicate changes in the immune condition of the birds. Our results suggest that this low breeding success population begins its breeding period with a poor body condition that it continues to decline throughout the season. Those poor body conditions added to the need for recovery for the next migration may be the cause of the abandonment of almost totally feathered chicks. Our evidence highlights the importance of food availability, in either the breeding or wintering sites, or both, on the health of the populations of migratory top predators.Facultad de Ciencias Naturales y Muse

Early Neural Markers of Implicit Attitudes: N170 Modulated by Intergroup and Evaluative Contexts in IAT

The Implicit Association Test (IAT) is the most popular measure to evaluate implicit attitudes. Nevertheless, its neural correlates are not yet fully understood. We examined event related potentials (ERPs) in response to face- and word processing while indigenous and non-indigenous participants performed an IAT displaying faces (ingroup and outgroup members) and words (positive and negative valence) as targets of category judgments. The N170 component was modulated by valence of words and by ingroup/outgroup face categorization. Contextual effects (face–words implicitly associated in the task) had an influence on the N170 amplitude modulation. On the one hand, in face categorization, right N170 showed differences according to the association between social categories of faces and affective valence of words. On the other, in word categorization, left N170 presented a similar modulation when the task implied a negative-valence associated with ingroup faces. Only indigenous participants showed a significant IAT effect and N170 differences. Our results demonstrate an early ERP blending of stimuli processing with both intergroup and evaluative contexts, suggesting an integration of contextual information related to intergroup attitudes during the early stages of word and face processing. To our knowledge, this is the first report of early ERPs during an ethnicity IAT, opening a new branch of exchange between social neuroscience and social psychology of attitudes

Diferencias en la alimentación del skúa pardo (Stercorarius antarcticus) en la península antártica: reproductivos vs no reproductivos

El skúa pardo, Stercorarius antarcticus, es un depredador oportunista que se alimenta de recursos terrestres (carroña, huevos y pichones de aves) y marinos (peces y crustáceos). En Bahía Esperanza, península Antártica, en las cercanías de la colonia reproductiva de pingüinos adelia (Pygoscelis adeliae) se encuentran gran cantidad de nidos y grupos no reproductivos (clubes) de skúas pardos. En este trabajo, se comparó la alimentación de estos dos grupos de skúas teniendo en cuenta su comportamiento alimenticio, mediante análisis de frecuencia de ocurrencia de los diferentes ítems presa presentes en egagrópilas.Facultad de Ciencias Naturales y Muse

Diferencias en la alimentación del skúa pardo (Stercorarius antarcticus) en la península antártica: reproductivos vs no reproductivos

El skúa pardo, Stercorarius antarcticus, es un depredador oportunista que se alimenta de recursos terrestres (carroña, huevos y pichones de aves) y marinos (peces y crustáceos). En Bahía Esperanza, península Antártica, en las cercanías de la colonia reproductiva de pingüinos adelia (Pygoscelis adeliae) se encuentran gran cantidad de nidos y grupos no reproductivos (clubes) de skúas pardos. En este trabajo, se comparó la alimentación de estos dos grupos de skúas teniendo en cuenta su comportamiento alimenticio, mediante análisis de frecuencia de ocurrencia de los diferentes ítems presa presentes en egagrópilas.Facultad de Ciencias Naturales y Muse

Diferencias en la alimentación del skúa pardo (Stercorarius antarcticus) en la península antártica: reproductivos vs no reproductivos

El skúa pardo, Stercorarius antarcticus, es un depredador oportunista que se alimenta de recursos terrestres (carroña, huevos y pichones de aves) y marinos (peces y crustáceos). En Bahía Esperanza, península Antártica, en las cercanías de la colonia reproductiva de pingüinos adelia (Pygoscelis adeliae) se encuentran gran cantidad de nidos y grupos no reproductivos (clubes) de skúas pardos. En este trabajo, se comparó la alimentación de estos dos grupos de skúas teniendo en cuenta su comportamiento alimenticio, mediante análisis de frecuencia de ocurrencia de los diferentes ítems presa presentes en egagrópilas.Facultad de Ciencias Naturales y Muse

Declining health status of Brown Skua (<i>Stercorarius antarcticus</i> lonnbergi) parents and their offspring during chick development

During breeding, Brown Skuas (Stercorarius antarcticus lonnbergi) perform a great physical effort in the care and maintenance of the nest. Interestingly, the breeding colony on which this work was conducted is in steady decline in recent years. In order to understand the physiological background responsible for the trade off between reproductive effort and health status, in adults and the possible reasons for the colony decline, we evaluated the health status in Brown Skuas parents and growing chicks and blood samples were obtained in three different breeding stages from adults: In (incubation), Er (after egg hatching), and Lr (during chick rearing) and from developing chicks. Serum albumin, α-, β-. and γ-globulin fractions, IgY level and corticosterone were determined in adults, while plasma proteins concentration, electrolytes, and γ-globulins were determined in chicks. Differences in albumin, α-, and γ-globulins and IgY levels were observed in adults through the reproductive stages, indicating a decline in nutritional status and immunocompetence during breeding. In addition, a decline in body condition and immune status was observed in growing chicks, indicating a close relationship between the decrease of the health status and reproductive effort performed by adults and the physiological status of the nestlings during development.Facultad de Ciencias Naturales y MuseoConsejo Nacional de Investigaciones Científicas y Técnica

Phenotypic plasticity in <i>Pygoscelis adeliae</i> physiology and immunity under anthropogenic pressure: a proteomic and biochemical scenario

The capacity of seabirds to shape their physiological and immune phenotypes may often be constrained by the ecological context. While phenotypic plasticity in physiological traits has been previously studied, the molecular mechanisms underlying phenotype plasticity in response to environmental stress have been little explored. This prompted us to enquire about how the nutritional and immune status are involved in physiological adaptations in breeding seabirds under anthropogenic pressure. At Esperanza (Hope) Bay, Antarctic Peninsula exists one of the biggest breeding penguin colony of Pygoscelis adeliae (Adelie). At this location, penguins nest nearby the Argentinian Esperanza Station and, therefore, are exposed to high levels of disturbance, whereas there is a low disturbed area, where penguins also breed far away from the Station. In both areas, the nutritional and immune status in breeding individuals was addressed and serum protein expression level was analyzed using a proteomic approach. Body mass, proteins, albumin, and triacylglycerol were higher in penguins from the low disturbance area, whereas uric acid increased in individuals from the disturbed area, indicating a poorer body condition of penguins under anthropogenic pressure. Immune responses were elevated in penguins from the disturbed area (IgY, γ-globulins and hemagglutinating activity). Finally, individuals breeding under anthropogenic pressure overexpressed proteins with immune, antioxidant, and metabolic functions. The poor nutritional status of penguins under disturbance may be the consequence of the reallocation of resources to the immune system. Altogether, this would constitute a potential strategy to preserve an adequate immune phenotype under stressed environments.Facultad de Ciencias Naturales y MuseoInstituto de Biotecnología y Biología Molecula

Justificación del uso de la TCHC en la evaluación del soporte óseo en enfermedad periodontal

38 p.Los signos de la enfermedad periodontal se pesquisan de manera clínica y radiográfica. Los exámenes imagenológicos de primera elección son las radiografías convencionales, y complementan la información clínica. Sin embargo, las radiografías pueden entregar información limitada, debido a la sobreproyección de estructuras, esto debido a la reproducción bidimensional de estructuras tridimensionales. Para superar esto, surge la posibilidad de usar la tomografía computarizada de haz cónico. Esta genera imágenes tridimensionales y en cualquier plano del espacio, de las estructuras de soporte óseo periodontal, aunque con dosis de radiación ionizante que suele ser mayor que las radiografías convencionales. Por lo tanto, la indicación de uso de tomografía computarizada de haz cónico debe ser justificada. El modelo jerárquico de eficacia diagnóstica y las guías clínicas respaldan la indicación de tomografía computarizada de haz cónico para evaluar el soporte óseo periodontal en pacientes con defectos intraóseos y de furca, además de mencionar la utilidad en planificación y control de procedimientos quirúrgicos regenerativos. La literatura recomienda indicar tomografía computarizada de haz cónico sólo cuando la evaluación clínica y radiográfica convencional no aportan la información necesaria para un correcto diagnóstico y planificación de tratamiento, por lo que como primera elección no es indicada. // ABSTRACT: Periodontal disease signs are detected by clinical and radiographic examination. First choice radiographic examinations are conventional radiographies, which complement clinical information. However, radiographies may bring limited information because of structure superimposition, which occurs because of two-dimensional reproduction of three-dimensional structures. To overcome this, emerges the possibility to use cone-beam computed tomography. This produces images in all three-dimensions of space of periodontal bone support structures, usually with higher dose of ionizing radiation than conventional radiographies. Therefore, cone-beam computed tomography indication must be justified. The hierarchical model of diagnostic efficacy and practice guidelines support the indication of cone-beam computed tomography for periodontal bone support evaluation in patients with infrabony and furcation defects, also considering the utility in planning and control of regenerative surgical treatments. Literature recommends cone-beam computed tomography only when clinical and conventional radiographic evaluation does not provide necessary information for a correct diagnosis and treatment planning, so it is not indicated as a first choice imagining method