Self-Organization, Layered Structure, and Aggregation Enhance Persistence of a Synthetic Biofilm Consortium

Microbial consortia constitute a majority of the earth’s biomass, but little is known about how these cooperating communities persist despite competition among community members. Theory suggests that non-random spatial structures contribute to the persistence of mixed communities; when particular structures form, they may provide associated community members with a growth advantage over unassociated members. If true, this has implications for the rise and persistence of multi-cellular organisms. However, this theory is difficult to study because we rarely observe initial instances of non-random physical structure in natural populations. Using two engineered strains of Escherichia coli that constitute a synthetic symbiotic microbial consortium, we fortuitously observed such spatial self-organization. This consortium forms a biofilm and, after several days, adopts a defined layered structure that is associated with two unexpected, measurable growth advantages. First, the consortium cannot successfully colonize a new, downstream environment until it selforganizes in the initial environment; in other words, the structure enhances the ability of the consortium to survive environmental disruptions. Second, when the layered structure forms in downstream environments the consortium accumulates significantly more biomass than it did in the initial environment; in other words, the structure enhances the global productivity of the consortium. We also observed that the layered structure only assembles in downstream environments that are colonized by aggregates from a previous, structured community. These results demonstrate roles for self-organization and aggregation in persistence of multi-cellular communities, and also illustrate a role for the techniques of synthetic biology in elucidating fundamental biological principles

A new class of glycomimetic drugs to prevent free fatty acid-induced endothelial dysfunction

Background: Carbohydrates play a major role in cell signaling in many biological processes. We have developed a set of glycomimetic drugs that mimic the structure of carbohydrates and represent a novel source of therapeutics for endothelial dysfunction, a key initiating factor in cardiovascular complications. Purpose: Our objective was to determine the protective effects of small molecule glycomimetics against free fatty acid­induced endothelial dysfunction, focusing on nitric oxide (NO) and oxidative stress pathways. Methods: Four glycomimetics were synthesized by the stepwise transformation of 2,5­dihydroxybenzoic acid to a range of 2,5­substituted benzoic acid derivatives, incorporating the key sulfate groups to mimic the interactions of heparan sulfate. Endothelial function was assessed using acetylcholine­induced, endotheliumdependent relaxation in mouse thoracic aortic rings using wire myography. Human umbilical vein endothelial cell (HUVEC) behavior was evaluated in the presence or absence of the free fatty acid, palmitate, with or without glycomimetics (1µM). DAF­2 and H2DCF­DA assays were used to determine nitric oxide (NO) and reactive oxygen species (ROS) production, respectively. Lipid peroxidation colorimetric and antioxidant enzyme activity assays were also carried out. RT­PCR and western blotting were utilized to measure Akt, eNOS, Nrf­2, NQO­1 and HO­1 expression. Results: Ex vivo endothelium­dependent relaxation was significantly improved by the glycomimetics under palmitate­induced oxidative stress. In vitro studies showed that the glycomimetics protected HUVECs against the palmitate­induced oxidative stress and enhanced NO production. We demonstrate that the protective effects of pre­incubation with glycomimetics occurred via upregulation of Akt/eNOS signaling, activation of the Nrf2/ARE pathway, and suppression of ROS­induced lipid peroxidation. Conclusion: We have developed a novel set of small molecule glycomimetics that protect against free fatty acidinduced endothelial dysfunction and thus, represent a new category of therapeutic drugs to target endothelial damage, the first line of defense against cardiovascular disease

Links between perception of parental actions and prosocial behavior in early adolescence

We analyzed the links between parental styles, practices, and empathy and specific forms of prosocial behaviors in early adolescence. The Argentine scale of perception of relationships with parents for children and young adolescents, prosocial tendencies measure, parenting practices measure, and children’s perception of parental empathy were administered to a sample of 289 middle class children, aged 10–16, of both sexes, from primary and secondary schools in Buenos Aires, Argentina. Correlations and hierarchical regressions were used to examine (1) relationships between parental styles, children’s perception of parental empathy, parental practices, and children’s prosocial behavior, (2) the amount of unique prediction from parental styles, children’s perception of parental empathy, and parental practices to children’s prosocial behavior. Results indicated that different aspects of parental actions (parental styles, practice, and empathy) have a differential relation according to the type of prosocial behavior involved. When taking these three kinds of parental behavior into account, parental styles are related to public and responsive aspects especially through extreme control by the mother. Parental practices, in turn, are related mainly with anonymous and altruistic aspects, but with this latter negatively. Finally, adolescents’ perception of parental empathy explains added variance in all the cases, though to a lesser extent.Fil: Richaud, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Centro Interdisciplinario de Investigaciones En Psicología Matemática y Experimental Dr. Horacio J.a Rimoldi; ArgentinaFil: Mesurado, Maria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Centro Interdisciplinario de Investigaciones En Psicología Matemática y Experimental Dr. Horacio J.a Rimoldi; ArgentinaFil: Lemos, Viviana Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Centro Interdisciplinario de Investigaciones En Psicología Matemática y Experimental Dr. Horacio J.a Rimoldi; Argentin

Perception of Parenting Style by Children with ADHD and Its Relation with Inattention, Hyperactivity/Impulsivity and Externalizing Symptoms

Children’s perception of their parents’ behavior is very important for their adjustment. Raising a child with Attention-Deficit/Hyperactivity Disorder (ADHD) can be particularly challenging. However, little is known about how children with ADHD perceive their parents’ childrearing style. The main purpose of this paper is to study how children with ADHD perceive acceptance and control in parent–child relationships and this perception’s relationship with inattention, hyperactivity/impulsivity, and externalizing behaviors. Participants were children between 7 and 13 years old with ADHD who were attending psychotherapy (ADHD), children without ADHD who were attending psychotherapy (APG), and children with unknown ADHD status who were not attending psychotherapy (NPG). Furthermore, one parent of each child participated in the study. An analysis of variance (ANOVA) showed that children with ADHD perceived higher levels of pathological control in their relationships with their mothers than did APG and NPG children. NPG children perceived higher extreme autonomy than ADHD and APG children. Linear regression analyses revealed that the perception of pathological parental control and extreme autonomy predicted externalizing symptoms in children with ADHD. The perception of maternal acceptance and pathological control predicted inattention in APG children. Also, perceived maternal pathological control and perceived paternal acceptance predicted externalizing symptoms in APG children. Thus, these results show the importance of taking into account children’s perception of their relationships with their parents in addition to parental reports of their own behavior.Fil: Molina, María Fernanda. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Musich, Francisco Martín. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; Argentina. Universidad Favaloro; Argentin

Friendship Relationships in Children and Adolescents: Positive Development and Prevention of Mental Health Problems

Studying childhood and adolescence from the perspective of Positive Development involves seeing them from the creation of skills and values that allow the child and the adolescent to move towards adulthood in a successful way, as well as considering them from the avoidance and prevention of violence, addiction, depression and other mental health problems.Developmental Psychology theorists such as Harry Stack Sullivan have put forward that friendships can provide a unique developmental context in which children and adolescents learn about Conflict and Negotiation and develop Perspective Taking Skills and Empathic Concern; also in that relationship, furthermore, they satisfy social needs of Companionship and Intimacy.First of all, in this chapter it is presented the Argentine adaptation of Bukowski Friendship Quality Scale (children´s version), an instrument that evaluates friendship quality and explores six dimensions of peer relationships: Companionship, Balance, Conflict, Help, Security and Closeness.Subsequently, two studies conducted with this instrument, in the adolescent version, are presented. The first study evaluates the relationship between Friendship quality and Loneliness feelings in adolescents. It is observed that the rejection of peers and loneliness self-perception feelings with their peers, are negatively correlated with Friendship quality dimensions: Balance, Companionship, Help, Security and Closeness. The Conflict Friendship dimension correlates positively with Family loneliness and Peer loneliness.In the second study, it is presented the results of the hierarchical regressions performed to evaluate Empathy and Values dimensions as predictive variables of Friendship Quality dimensions. Regarding Value Scale, Honesty is the best predictor of Friendship Quality dimensions; and regarding Empathy, Perspective Taking and Empathic Concern are the best predictors of Friendship Quality dimensions.Finally, it is considered how these contributions highlight the important role of friendship and peer relationships in the prevention of mental health problems.Fil: Rodriguez, Lucas Marcelo. Pontificia Universidad Catolica Argentina "santa Maria de Los Bs. As.". Facultad Teresa de Avila. Centro de Investigacion Interdisciplinar En Valores, Integracion y Desarrollo Social.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Moreno, José Eduardo. Pontificia Universidad Catolica Argentina "santa Maria de Los Bs. As.". Facultad Teresa de Avila. Centro de Investigacion Interdisciplinar En Valores, Integracion y Desarrollo Social.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mesurado, Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Centro Interdisciplinario de Investigaciones en Psicología Matemática y Experimental Dr. Horacio J. A. Rimoldi; Argentin