On Maltsev digraphs

The original publication is available at www.springerlink.com Copyright SpringerWe study digraphs preserved by a Maltsev operation, Maltsev digraphs. We show that these digraphs retract either onto a directed path or to the disjoint union of directed cycles, showing that the constraint satisfaction problem for Maltsev digraphs is in logspace, L. (This was observed in [19] using an indirect argument.) We then generalize results in [19] to show that a Maltsev digraph is preserved not only by a majority operation, but by a class of other operations (e.g., minority, Pixley) and obtain a O(V G4)-time algorithm to recognize Maltsev digraphs. We also prove analogous results for digraphs preserved by conservative Maltsev operations which we use to establish that the list homomorphism problem for Maltsev digraphs is in L. We then give a polynomial time characterisation of Maltsev digraphs admitting a conservative 2-semilattice operation. Finally, we give a simple inductive construction of directed acyclic digraphs preserved by a Maltsev operation.Peer reviewe

Early release from prison in time of COVID-19: Determinants of unfavourable decisions towards Black prisoners

On the onset of the COVID-19 pandemic, the overcrowding in prisons led to efforts to decarcerate in order to prevent and control outbreaks in prisons. This study analyses how public support for such exceptional measures are determined by cognitive and ideological factors known to create and maintain racial biases in the criminal system. Participants were asked to express their level of agreement with the early-release of hypothetical prisoners. Results showed participants to be less favourable to the early-release of Black compared to White prisoners, when they had committed a stereotypically Black crime. As expected, the congruency between the crime stereotypicality and the colour of the prisoner's skin did not emerge for White prisoners. Moreover, the difference between the agreement with the release of the Black vs. the White prisoner when both committed a stereotypically Black crime was higher as the level of endorsement of Meritocracy increased. Contrastingly, Anti-egalitarianism only predicted an overall disagreement with prisoners' early-release. This paper highlights the cumulative explanation by different levels of analysis of this current problem and implications for the development of the public opinion on penal subjects.info:eu-repo/semantics/publishedVersio

Degradation of fluoroanilines by the wild strain Labrys portucalensis

Aromatic amine compounds, many of them with halogenated substituents, constitute a major class of environmental pollutants that have been released into soil and water due to extensive use in industries and agriculture. Biodegradation has been found to be a major route for the removal of this kind of toxic and recalcitrant pollutants from the environment. Whereas the degradation of mono- and dichlorinated anilines has been studied, very little is known about fluorinated anilines. Therefore, the objective of this study was to investigate, under aerobic conditions, the degradation of 2-, 3- and 4-fluoroaniline by a previously isolated pure bacterium, designated as strain F11. This microorganism, identified as Labrys portucalensis, was isolated from a contaminated site in northern Portugal and has the unique capacity to utilize fluorobenzene as a sole carbon and energy source,. The results of the biodegradation of 2-, 3- and 4-fluoroaniline by strain F11 showed that this microorganism is able to completely degrade 2- fluoroaniline and partially degrade 4-fluoroaniline, when these compounds are present as a sole carbon and energy source. Biodegradation of these two compounds also occurred, although at a lower rate, in the absence of an external nitrogen source in the culture medium. To our knowledge, this is the first study reporting the biodegradation of 2- and 4-fluoroaniline as a sole carbon and energy source by a pure microbial culture. C.L. Amorim and M.F. Carvalho wish to acknowledge a research grant from Fundação para a Ciência e Tecnologia (FCT), Portugal (Ref. SFRH/BD/47109/2008 and SFRH/BPD/44670/2008, respectively) and Fundo Social Europeu (III Quadro Comunitário de Apoio). This work was supported by the FCT Project - PTDC/BIO/67306/200

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

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

Biological treatment of a contaminated gaseous emission from a leather industry in a suspended-growth bioreactor

A suspended-growth bioreactor (SGB) was operated for the treatment of a gaseous stream mimicking emissions generated at a leather industrial company. The main volatile organic compounds (VOCs) present in the gaseous stream consisted of 1-methoxy-2-propanol, 2,6-dimethyl-4-heptanone, 2-butoxyethanol, toluene and butylacetate. A microbial consortium able to degrade these VOCs was successfully enriched. A laboratory- scale SGB was established and operated for 210-d with an 8 h cycle period and with shutdowns at weekends. Along this period, the SGB was exposed to organic loads (OL) between 6.5 and 2.3 £ 102 g h¡1 m¡3. Most of the compounds were not detected at the outlet of the SGB. The highest total VOC removal efficiency (RE) (ca 99%) was observed when an OL of 1.6 £ 102 g h¡1 m¡3 was fed to the SGB. The maximum total VOC elimination capacity (1.8 £ 102 g h¡1 m¡3) was achieved when the OL applied to the SGB was 2.3 £ 102 g h¡1 m¡3. For all the operating conditions, the SGB showed high levels of degradation of toluene and butylacetate (RE t 100%). This study also revealed that recirculation of the gaseous effluent improved the performance of the SGB. Overall, the SGB was shown to be robust, showing high performance after night and weekend shutdown periods.info:eu-repo/semantics/acceptedVersio

Collagen from Atlantic cod (Gadus morhua) skins extracted using CO2 acidified water with potential application in healthcare

This work has received funding from European Union, under the scope of European Regional Development Fund (ERDF) through the Structured Project NORTE-01-0145-FEDER-000021 (Norte2020) and under the scope of the European Union Seventh Framework Programme (FP7/2007-2013) through grant agreement ERC-2012-ADG 20120216-321266 (ERC Advanced Grant ComplexiTE). PhD grant of C. O. (Norte-08-5369-000037) with financial support by Norte 2020. The authors would like to acknowledge Frigoríficos da Ermida, Lda. (Gafanha da Nazaré, Portugal) for the kind offer of Atlantic cod skins and to Dr. Manuela Pintado, Dr. Raquel Madureira and Joana Costa (Universidade Católica Portuguesa, Porto) for the use of microDSC and assistance during measurements. The authors also thank to Dr. Catarina Marques and Dr. Sandra Pina (3B’s Research Group) for assistance on XRD measurements, to Dr. Rita Lopez-Cebral (3B’s Research Group) for assistance on SEC measurements and to Dr. Alexandre Barros for discussions.The extraction of collagen from fish skins is being proposed as strategy for valorization of marine origin by-products, being a sustainable alternative to mammal collagen. The method commonly uses solutions of organic acids, but new methodologies are arising, aiming to improve process yields and/or the properties of the resulting products. In this work, skins removed from salt brine Atlantic cod (Gadus morhua) were used to extract collagen, using water acidified with CO2, obtaining an extraction yield of 13.8% (w/w). Acidified water extracted collagen (AWC) presented a total content of proline-like amino acids of 151/1000 residues, with a degree of hydroxylation of 38%, and its SDS-PAGE profile is compatible with type I collagen. Moreover, FTIR, CD and XRD results suggest the presence of preserved triple helix, having a denaturation temperature of 32.3 °C as determined by micro-DSC. AWC exhibited a typical shear thinning behavior, interesting regarding their further processing, namely in jelly-like formulations. Additionally, the presence of AWC in MRC-5 human fibroblasts culture did not affect cell viability, demonstrating the non-cytotoxic behavior. Overall, the results support the efficiency of the proposed approach for collagen extraction and further enable the design of methodologies to address AWC use in biomedical or cosmetic context.authorsversionpublishe