165 research outputs found
Support for group-based inequality among members of low-status groups as an ingroup status-enhancement strategy
We discuss the idea that competition-based motives boost low-status group members’ support for group-based hierarchy and inequality. Specifically, the more low-status group members feel motivated to compete with a relevant high-status outgroup, based on the belief that existing status positions may be reversed, the more they will defend status differentials (i.e., high social dominance orientation; SDO). Using minimal groups (N = 113), we manipulated ingroup (low vs. high) status, and primed unstable status positions to all participants. As expected, we found that SDO positively mediates the relation between ingroup identification and collective action, when ingroup’s status is perceived to be low and status positions are perceived as highly unstable. We discuss the implications of considering situational and contextual factors to better understand individuals’ support for group-based hierarchies and inequality, and the advantages of considering ideological processes in predicting collective action.info:eu-repo/semantics/publishedVersio
Functional cell microcarriers: a new platform for cell separation and expansion
Publicado em "Journal of Tissue Engineering and Regenerative Medicine", vol. 7, supp. 1 (2013)The success of many stem cell applications in the biomedical field is highly dependent on the
development of separation techniques for isolation and purification of cells with a very high yield and
purity. Despite all the achievements made in the field over the past several years, new systems for
effective cell separation are still needed. Previous work from our group demonstrated that functional
chitosan films grafted with antibodies promote selective cell adhesion. 1
Herein we developed chitosan microparticles able to capture a specific cell types based in the concept
of antibody coating for cell sorting. Our goal was to create new biomaterial surfaces capable of recruit a
specific cell population within a mixture, reducing cell manipulation and time-consuming allowing at the
same time cell expansion. Such system acts as a microcarrier for cell expansion of a specific cell
target. Microcarrier culture system offers the advantage of providing a larger surface area for the
growth of anchorage-dependent cells in a suspension culture system. Chitosan was chosen due to the
excellent biocompatibility, gel forming properties, chemistry surface and low cell adhesion. This allows
the modification with specific biochemical cues, for a controllable cell attachment. Here we develop
functional biotinylated microparticles, such system allows tailoring microparticles to a variety of
functional biomolecules. Here we tested the immobilization of antibodies to target specific cell types,
CD31 for endothelial cells and CD90 for adipose stem cells.
Primarily designed for an application in tissue engineering, two main challenges are accomplished with
the herein presented microparticles: separation and scale-up expansion of specific cell type. The herein
developed polymeric microparticles can also be used for directly deliver cells in vivo to repair and
regenerate tissues
Functional chitosan microcarriers for selective cell attachment and expansion
The success of many stem cell applications in the biomedical field is highly dependent on the development of reliable techniques either for isolation or selection of specific cell populations with a very high yield and purity.1 In this work we propose the use of chitosan microparticles (μPs) to capture a specific cell type based in the concept of antibody-antigen binding. Our goal was to create new biomaterials capable of selecting within a heterotypic cell suspension, a specific sub-population, and supporting subsequent cell expansion. Such system simultaneously allows the selection and acts as a microcarrier for a specific target, thus reducing cell manipulation and time-consumption
Geochemical fingerprinting of Roman pottery production from Manta Rota kilns (Southern Portugal)
The Roman site of Manta Rota, located in Algarve region, Portugal, is known from the XIXth century when Estacio da Veiga recovered a few pottery fragments and identified the foundations of Roman structures. References in early XXth century refer to a pottery kiln and to the remains of both amphorae and lamps. In 1992, emergency excavations directed by Cristina Garcia excavated a structure identified as a kiln and recovered abundant amphorae fragments of a locally produced Dressel 14 type. There is evidence of production of tiles, common ware and amphora. The study of the remains collected (terra sigillata and amphorae) in the excavations shows that Roman occupation of the site covers a period from the middle of the 1st century until the 5th century AD. The major production of the kiln area was the Dressel 14 fish sauce amphora centered in the middle/second half of the 1st century but the production of Almagro 51c is also attested. A preliminary macroscopic analysis of both the amphorae and the common ware show identical features. The aim of this paper is to present chemical characterization of the production of Manta Rota and to compare the results with different workshops in the Algarve region as Quinta do Lago, near Faro or S. Bartolomeu de Castro Marim, in the proximity of the studied area, in order to establish geochemical fingerprints of Manta Rota ceramic production center. Preliminary results point to a fine geochemical differentiation of the Manta Rota ceramics in comparison with the other two roman production centers of Algarve region
The effect of chitosan on the in vitro biological performance of chitosan-poly(butylene succinate) blends
Chitosan blends with synthetic biodegradable polymers have been proposed for various biomedical applications
due to their versatile mechanical properties and easier processing. However, details regarding the main surface
characteristics that may benefit from the blending of these two types of materials are still missing. Hence, this
work aims at investigating the surface properties of chitosan-based blends, illustrating the way these properties
determine the material-proteins interactions and ultimately the behavior of osteoblast-like cells. The surface
characteristics of modified and nonmodified blends were assessed using complimentary techniques such as optical
microscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR-ATR), X-ray
photoelectron spectroscopy (XPS), contact angle measurements and surface energy calculations. The adsorption
of human serum albumin (HSA) and human plasma fibronectin (HFN) onto the different surfaces was quantified
by association of an indirect method with a colorimetric assay. It was found that the presence of chitosan on the
surface promoted the adsorption of proteins. Moreover, a preferential adsorption of albumin over fibronectin was
registered. The in vitro biological performance of the studied materials was further investigated by a direct contact
assay with an osteoblastic-like cell line (SaOs-2). A synergistic effect of the two components of the blend was
observed. While the synthetic polyester promoted the adhesion of SaOs-2, the presence of chitosan significantly
enhanced the osteoblastic activity of these cells. This work further confirmed the interest in designing polymeric
blends with natural polymers as a successful strategy to enhance the biological performance of a biomaterial
Social Dominance Orientation Boosts Collective Action Among Low-Status Groups
We propose that low-status group members' support for group-based hierarchy and inequality (i.e., social dominance orientation; SDO) may represent an ideological strategy to guarantee the legitimacy of future ingroup status-enhancement. Specifically, we argue that, under unstable social structure conditions, SDO serves as an ideological justification for collective action tendencies aimed at competing for a higher status. In such context, SDO should be positively related with actions aimed to favor the ingroup (i.e., collective actions) by increasing group members' motivation to engage in direct competition with a relevant higher-status outgroup. We conducted two studies under highly competitive and unstable social structure contexts using real life groups. In Study 1 (N = 77), we induced Low vs. High Ingroup (University) Status and in Study 2 (N = 220) we used competing sports groups. Overall, results showed that, among members of low-status groups, SDO consistently increased individuals' motivation to get involved in actions favoring the ingroup, by boosting their motivation to compete with the opposing high-status outgroup. We discuss the results in light of the social dominance and collective action framework.info:eu-repo/semantics/publishedVersio
Essential genetic findings in neurodevelopmental disorders
Neurodevelopmental disorders (NDDs) represent a growing medical challenge in modern societies. Ever-increasing sophisticated diagnostic tools have been continuously revealing a remarkably complex architecture that embraces genetic mutations of distinct types (chromosomal rearrangements, copy number variants, small indels, and nucleotide substitutions) with distinct frequencies in the population (common, rare, de novo). Such a network of interacting players creates difficulties in establishing rigorous genotype-phenotype correlations. Furthermore, individual lifestyles may also contribute to the severity of the symptoms fueling a large spectrum of gene-environment interactions that have a key role on the relationships between genotypes and phenotypes.Herein, a review of the genetic discoveries related to NDDs is presented with the aim to provide useful general information for the medical community.info:eu-repo/semantics/publishedVersio
Knowledge and beliefs about herb/supplement consumption and herb/supplement–drug Interactions among the general population, including healthcare professionals and pharmacists: a systematic review and guidelines for a smart decision system
The increased consumption of a variety of herbs/supplements has been raising serious health concerns. Owing to an inadequate understanding of herb/supplement–drug interactions, the simultaneous consumption of these products may result in deleterious effects and, in extreme cases, even fatal outcomes. This systematic review is aimed at understanding the knowledge and beliefs about the consumption of herbs/supplements and herb/drug–supplement interactions (HDIs). The study follows the PRISMA guidelines. Four online databases (Web of Science; PubMed; Cochrane; and EBSCOhost) were searched, and a total of 44 studies were included, encompassing 16,929 participants. Herb and supplement consumption is explained mostly by the reported benefits across multiple conditions and ease of use. Regarding HDIs, most people take both herbs/supplements and prescription drugs simultaneously. Only a small percentage of participants have knowledge about their interaction effects, and many reported adverse interactions or side effects. Nevertheless, the main reason for stopping the prescribed drug intake is the perceived lack of its effect, and not due to interactions. Therefore, it is important to increase the knowledge about supplement use so that further strategies can be elaborated to better detect or be alert for whenever a potentially dangerous reaction and/or interaction may occur. This paper raises awareness regarding the need for developing a decision support system and ends with some considerations about the development of a technological solution capable of detecting HDIs and, thereby, aiding in the improvement of pharmacy services.info:eu-repo/semantics/publishedVersio
Evidence of Genetic Segregation among Meagre (Argyrosomus regius) Atlantic Spawning Areas
The meagre Argyrosomus regius, one of the largest sciaenidae in the world, is a valuable resource for fisheries and aquaculture. Despite its socioeconomic relevance, knowledge about population dynamics and wild stocks is still scarce, and conservation risks are associated with overexploitation. Two genetic distinct groups, one in the North Atlantic Ocean and one in the eastern Mediterranean Sea, were identified by previous studies. However, little is known about the genetic structure of the Atlantic group, where four important spawning areas have been identified. To assess if each spawning area is an independent breeding unit, the genetic diversity, populational structure, and demographic history of A. regius along the North–East and Eastern Central Atlantic coast were analyzed, using 15 microsatellite loci. Results corroborate the hypothesis tested, suggesting four genetic groups: a first group encompassing individuals from the Gironde spawning area, a second group encompassing individuals from the Tagus spawning area, a third group corresponding to individuals captured in the Algarve region, and a forth group gathering individuals from Morocco and Mauritania. This study reveals the need for specific fisheries management plans considering genetic structure information, and highlights the need for international cooperation.info:eu-repo/semantics/publishedVersio
Evidence of Genetic Segregation among Meagre (Argyrosomus regius) Atlantic Spawning Areas
The meagre Argyrosomus regius, one of the largest sciaenidae in the world, is a valuable resource for fisheries and aquaculture. Despite its socioeconomic relevance, knowledge about population dynamics and wild stocks is still scarce, and conservation risks are associated with overexploitation. Two genetic distinct groups, one in the North Atlantic Ocean and one in the eastern Mediterranean Sea, were identified by previous studies. However, little is known about the genetic structure of the Atlantic group, where four important spawning areas have been identified. To assess if each spawning area is an independent breeding unit, the genetic diversity, populational structure, and demographic history of A. regius along the North-East and Eastern Central Atlantic coast were analyzed, using 15 microsatellite loci. Results corroborate the hypothesis tested, suggesting four genetic groups: a first group encompassing individuals from the Gironde spawning area, a second group encompassing individuals from the Tagus spawning area, a third group corresponding to individuals captured in the Algarve region, and a forth group gathering individuals from Morocco and Mauritania. This study reveals the need for specific fisheries management plans considering genetic structure information, and highlights the need for international cooperation
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