'A boy would be friends with boys... and a girl... with girls' : gender norms in early adolescent friendships in Egypt and Belgium

Purpose: A gender analysis was conducted to illuminate the key elements of friendships highlighted by early adolescent girls and boys in two sites for the purpose of better understanding the impact of gender norms on adolescent friendships in different contexts. Methods: Narrative interviews with early adolescents were conducted in two sites: Assiut, Egypt (n = 37) and Ghent, Belgium (n = 30). The interviews were recorded, transcribed, translated into English, and coded using Atlas.ti for analysis. Results: In both Assiut and Ghent, early adolescents reported some similarities in defining key characteristics of their same-sex friends as well as in the activities they share. However, differences were noticed among boys and girls within each site. In addition, the scope of shared activity was broader in Ghent than in Assiut. In both sites, few opposite-sex friendships were reported. Gender norms influenced choice of friends as well as the type and place of shared activities. Conclusions: Building on knowledge that adolescent friendships guide and reinforce attitudes, beliefs, and behaviors that impact immediate and long-term health, our findings indicate that gender norms inform early adolescent friendships, which may impact healthy development

Low-power, 10-Gbps 1.5-Vpp differential CMOS driver for a silicon electro-optic ring modulator

We present a novel driver circuit enabling electro-optic modulation with high extinction ratio from a co-designed silicon ring modulator. The driver circuit provides an asymmetric differential output at 10Gbps with a voltage swing up to 1.5V(pp) from a single 1.0V supply, maximizing the resonance-wavelength shift of depletion-type ring modulators while avoiding carrier injection. A test chip containing 4 reconfigurable driver circuits was fabricated in 40nm CMOS technology. The measured energy consumption for driving a 100fF capacitive load at 10Gbps was as low as 125fJ/bit and 220fJ/bit at 1V(pp) and 1.5V(pp) respectively. After flip-chip integration with ring modulators on a silicon-photonics chip, the power consumption was measured to be 210fJ/bit and 350fJ/bit respectively

Exploration of gender norms and socialization among early adolescents : the use of qualitative methods for the global early adolescent study

Purpose: The Global Early Adolescent Study (GEAS) was launched in 2014 with the primary goal of understanding the factors in early adolescence that predispose young people to subsequent sexual risks, and conversely, those that promote healthy sexuality across different cultural contexts. The present article describes the methodology that was used for the first phase of GEAS, which consisted of conducting qualitative research to understand the gendered transitions into adolescence and the role that gender norms play within the key relationships of adolescents. Researchers from each of the sites that had completed data collection were also elicited for their feedback on the key strengths, challenges, and lessons learned from conducting research among 11- to 14-year-old adolescents. The purpose of this article is to present the description of each of the methods that were used in GEAS, as well as the researchers' perspectives of using the methods among early adolescents in their sites. Methods: The GEAS is being implemented through a collaboration of university and nongovernmental institutions from 15 cities: Assiut (Egypt) Baltimore (U.S.), Blantyre (Malawi), Cape Town (South Africa), Cochabomba (Bolivia), Cuenca (Ecuador), Edinburgh (Scotland), Ghent (Belgium), Hanoi (Vietnam), Ile-Ife (Nigeria), Kinshasa (DRC), Nairobi (Kenya), New Delhi (India), Ouaga-dougou (Burkina Faso), and Shanghai (China). Approximately 30 in-depth interviews among adolescents and 30 in-depth interviews with their parent/guardian were conducted at each site, with adults and adolescents interviewed separately. To build trust and increase engagement among the adolescent participants, we used two different visual research methods: (1) timeline exercise which was small group based and (2) the Venn diagram exercise which was conducted individually and used at the start of the in-depth interview. Results: The visual aspects of both the timeline and the Venn diagrams not only helped to produce data for the purposes of the study, but also were a successful way of engaging the adolescent participants across sites. While the narrative interviews produced extremely rich data, researchers did notice that there were a few challenges among the younger adolescents. Challenges were related to the length of the interview, comprehension of questions, as some of the questions were either too abstract or asked adolescents about an experience they had not yet had and therefore could not address or articulate. Conclusions: Conducting the first phase of GEAS revealed important insights for research with participants who are in this developmental phase of early adolescence. Methods that involve greater engagement and those that are visual were shown to work well irrespective of the cultural setting

Marching to a different drummer : a cross-cultural comparison of young adolescents who challenge gender norms

Purpose: Little is known about how gender norms regulate adolescents' lives across different cultural settings. This study aims to illustrate what is considered as violating gender norms for boys and girls in four urban poor sites as well as the consequences that follow the challenging of gender norms. Methods: Data were collected as part of the Global Early Adolescent Study, a 15-country collaboration to explore gender norms and health in early adolescence. The current study analyzed narrative and in-depth interviews conducted in urban poor sites in two middle-income (Shanghai, China; and New Delhi, India) and two high-income countries (Baltimore, U.S.; and Ghent, Belgium). A total of 238 participants, 59 boys and 70 girls aged 11-13 years old and 109 of their parents/guardians (28 male adults and 81 female adults), were interviewed. A thematic analysis was conducted across sites using Atlas. Ti 7.5 software. Results: Findings revealed that although most perceptions and expressions about gender were regulated by stereotypical norms, there was a growing acceptability for girls to wear boyish clothes and engage in stereotypical masculine activities such as playing soccer/football. However, there was no comparable acceptance of boys engaging in traditional feminine behaviors. Across all sites, challenging gender norms was often found to lead to verbal, physical, and/or psychological retribution. Conclusions: While it is sometimes acceptable for young adolescents to cross gender boundaries, once it becomes clear that a behavior is socially defined as typical for the other sex, and the adolescent will face more resistance. Researchers, programmers, and clinicians working in the field of adolescent health need not only attend to those who are facing the consequences of challenging prevailing gender norms, but also to address the environment that fosters exclusion and underscores differences

Functional Polymorphisms in PRODH Are Associated with Risk and Protection for Schizophrenia and Fronto-Striatal Structure and Function

PRODH, encoding proline oxidase (POX), has been associated with schizophrenia through linkage, association, and the 22q11 deletion syndrome (Velo-Cardio-Facial syndrome). Here, we show in a family-based sample that functional polymorphisms in PRODH are associated with schizophrenia, with protective and risk alleles having opposite effects on POX activity. Using a multimodal imaging genetics approach, we demonstrate that haplotypes constructed from these risk and protective functional polymorphisms have dissociable correlations with structure, function, and connectivity of striatum and prefrontal cortex, impacting critical circuitry implicated in the pathophysiology of schizophrenia. Specifically, the schizophrenia risk haplotype was associated with decreased striatal volume and increased striatal-frontal functional connectivity, while the protective haplotype was associated with decreased striatal-frontal functional connectivity. Our findings suggest a role for functional genetic variation in POX on neostriatal-frontal circuits mediating risk and protection for schizophrenia

Precipitation with polyethylene glycol followed by washing and pelleting by ultracentrifugation enriches extracellular vesicles from tissue culture supernatants in small and large scales

Extracellular vesicles (EVs) provide a complex means of intercellular signalling between cells at local and distant sites, both within and between different organs. According to their cell-type specific signatures, EVs can function as a novel class of biomarkers for a variety of diseases, and can be used as drug-delivery vehicles. Furthermore, EVs from certain cell types exert beneficial effects in regenerative medicine and for immune modulation. Several techniques are available to harvest EVs from various body fluids or cell culture supernatants. Classically, differential centrifugation, density gradient centrifugation, size-exclusion chromatography and immunocapturing-based methods are used to harvest EVs from EV-containing liquids. Owing to limitations in the scalability of any of these methods, we designed and optimised a polyethylene glycol (PEG)based precipitation method to enrich EVs from cell culture supernatants. We demonstrate the reproducibility and scalability of this method and compared its efficacy with more classical EV-harvesting methods. We show that washing of the PEG pellet and the re-precipitation by ultracentrifugation remove a huge proportion of PEG co-precipitated molecules such as bovine serum albumine (BSA). However, supported by the results of the size exclusion chromatography, which revealed a higher purity in terms of particles per milligram protein of the obtained EV samples, PEG-prepared EV samples most likely still contain a certain percentage of other non-EV associated molecules. Since PEG-enriched EVs revealed the same therapeutic activity in an ischemic stroke model than corresponding cells, it is unlikely that such co-purified molecules negatively affect the functional properties of obtained EV samples. In summary, maybe not being the purification method of choice if molecular profiling of pure EV samples is intended, the optimised PEG protocol is a scalable and reproducible method, which can easily be adopted by laboratories equipped with an ultracentrifuge to enrich for functional active EVs

Mujeres y cultura en la Argentina del siglo XIX

Este libro es el resultado de buscar y rebuscar, acuciadas en un primer momento por una natural curiosidad hacia el siglo XIX, en el baúl de nuestras abuelas o incluso bisabuelas. Y nos encontramos no sólo con el pasado sino con nuestro pasado, rico, complejo, sorprendente en su infinita variedad de hallazgos. Experimentamos un sentimiento de ternura por esas mujeres y de profunda solidaridad ante el esfuerzo que realizaron, muchas veces en condiciones inhóspitas, incomprendidas por sus contemporáneos, varones y mujeres. No sólo mujeres con nombre propio sino mujeres generalmente anónimas forman una parte esencial de la historia no contada, oculta(da) en el polvo acumulado durante el transcurso de los años. Nuestra tarea, nuestra pasión es desenvolverla, descubrirla, deconstruirla. Un acto compartido entre muchas mujeres y algunos varones. En mayor o menor grado, cada artículo en Mujeres y cultura en la Argentina del siglo XIXcontribuye a este fin y también al de la construcción –la re-construcción- de la historia de mujeres en la Argentina. Hay todavía mucho por revolver en esos arcones. Sabemos que hay nombres escondidos todavía en publicaciones que debemos encontrar. Nombres de mujeres, sus labores, que han sido muy poco investigadas o que sencillamente desconocemos. Se trata de hacer visible una producción ignorada y una tradición desdibujada