On the crystallization behavior of syndiotactic-b-atactic polystyrene stereodiblock copolymers, atactic/syndiotactic polystyrene blends, and aPS/sPS blends modified with sPS-b-aPS

International audienceCrystallization and morphological features of syndiotactic-b-atactic polystyrene stereodiblock copolymers (sPS-b-aPS), atactic/syndiotactic polystyrene blends (aPS/sPS), and aPS/sPS blends modified with sPS-b-aPS, with different compositions in aPS and sPS, have been investigated using differential scanning calorimetry (DSC), polarized light optical microscopy (POM) and wide angle X-ray diffraction (WAXRD) techniques. For comparative purposes, the properties of parent pristine sPS samples were also studied. WAXRD analyses revealed for all the samples, independently from their composition (aPS/sPS ratio) and structure (blends, block copolymers, blends modified with block copolymers), the same polymorphic β form of sPS. The molecular weight of aPS and sPS showed opposite effects on the crystallization of 50:50 aPS/sPS blends: the lower the molecular weight of aPS, the slower the crystallization while the lower the molecular weight of sPS, the faster the crystallization. DSC studies performed under both isothermal and non-isothermal conditions, independently confirmed by POM studies, led to a clear trend for the crystallization rate at a given sPS/aPS ratio (ca. 50:50 and 20:80): sPS homopolymers > sPS-b-aPS block copolymers ∼sPS/aPS blends modified with sPS-b-aPS copolymers > sPS/aPS blends. Interestingly, sPS-b-aPS block copolymers not only crystallized faster than blends, but also affected positively the crystallization behavior of blends. At 50:50 sPS/aPS ratio, blends (Blend-2), block copolymers (Cop-1) and blends modified with block copolymers (Blend-2-mod) crystallized via spherulitic crystalline growth controlled by an interfacial process. In all cases, an instantaneous nucleation was observed. The density of nuclei in block copolymers (160,000−190,000 nuclei mm−3) was always higher than that in blends and modified blends (30,000−60,000 nuclei mm−3), even for quite different sPS/aPS ratio. At 20:80 sPS/aPS ratio, the block copolymers (Cop-2) preserved the same crystallization mechanism than at 45:55 ratio (Cop-1). On the other hand, the 20:80 sPS/aPS blend (Blend-4) and blend modified with block copolymers (Blend-4-mod) showed a spinodal decomposition

Saint sinner or execrated saint? Self care in women with HIV

Esta pesquisa foi realizada com mulheres portadoras de HIV/Aids, integrantes de uma ONG no Distrito Federal, com o objetivo de conhecer seu processo de adesão ao autocuidado. Teve como objetivos investigar a relação entre o autocuidado e a sua auto-estima e auto-imagem, e como o conceito de autocuidado se relaciona com as suas vivências com o parceiro e com seus familiares. Problema: construção de significados sobre autocuidado por mulheres soropositivas para HIV. Instrumento: entrevista de grupo focal. As construções de sentido foram: histórias de descuido; eu até me cuido, se for para outra pessoa...; desqualificando-se para se relacionar! e profissionais como facilitadoras ou não de sua inclusão social. Os resultados caminharam no sentido de se perceber que a subjetividade dessas mulheres permanece sem alternativa de reedição e, portanto, atrelada à identidade de pecadora por ter o HIV e de santa por sofrer apartada para que os outros não se contaminem.This research was developed with HIV positive women, members of a NGO, in the Federal District, and its aim was to acknowledge their process of adhering to self-care. Its specific aims were to investigate the relation between self-care, self-esteem and self-image of these women, how the concept of self-care was related with their lives, their partners and their families. The main issue was the construction of meanings for self-care by these women. The instrument used was the focal-group interview. The "sense-zones" construed through the aualitative investigation method were: stories of abandonment; I'll look after myself only for the sake of someone else ; undermining themselves in their relationship! and professionals as a means for bridging them or not into social inclusion. The results showed that the subjectivity of these women remain without alternative, therefore linked with the identity of "sinner" for being HIV positive and of "saint" for suffering apart, so that the others will not be contaminated

Estudio de prefactibilidad y plan de gestión para la construcción de un centro recreacional evangélico en Cartagena

La Comunidad Evangélica, a nivel mundial cuenta hoy en día con varios servicios como librerías, canales de televisión, emisoras de radio, fundaciones, hoteles, empresas de publicidad, centro recreacionales, todos estos orientados bajo principios y valores cristianos que buscan dejar huella en la comunidad y aportar a una sociedad más armónica a la luz de la palabra del Creador; a nivel nacional, se encuentran librerías Cristianas tales como León de Judá, Librería Cristiana Shalom, y Círculo de Lectores Cristianos, también se encuentran sitios para servicios de Avivamientos como el Centro Mundial, Comunidad Cristiana La Unción - Canal 5 de UNE, Cadena Radial Auténtica, Periódico Valores Cristianos, Centro Misionero Bethesda, Fundación Ayudar de Colombia, Radio Huellas Cali, Shalom Hospedaje Cristiano, Centro Bíblico Internacional, Directorio Nacional Cristiano, entre otros. Sin embargo el país carece de un lugar de esparcimiento con las características de un centro recreacional en el que se pueda divertir y fortalecer las costumbres y creencias de los evangélicos, ya que estos por no tener opción visitan los sitios que promueven actividades recreativas a la comunidad en general, la cual ofrece diferentes atractivos y alternativas para la integración y el esparcimiento, a pesar de ello, algunas de las alternativas no califican dentro de las características de diversión que tienen las comunidades evangélicas, como es la forma en que se llevan a cabo los eventos sociales y musicales donde el consumo de licor y tabaco, los bailes y vestimenta atrevida se constituyen en ingredientes que nunca faltan.Incluye bibliografía, anexo

Functional resonance magnetic imaging (fMRI) in adolescents with idiopathic musculoskeletal pain: a paradigm of experimental pain

Background: Studies on functional magnetic resonance imaging (fMRI) have shown that adults with musculoskeletal pain syndromes tolerate smaller amount of pressure (pain) as well as differences in brain activation patterns in areas related to pain. The objective of this study was to evaluate, through fMRI, the brain activation in adolescents with idiopathic musculoskeletal pain (IMP) while performing an experimental paradigm of pain. Methods: The study included 10 consecutive adolescents with idiopathic musculoskeletal pain (average age 16.3 +/- 1.0) and 10 healthy adolescents age-matched. fMRI exams were performed in a 3 T scanner (Magnetom Trio, Siemens) using an event-related design paradigm. Pressure stimuli were performed in the nondominant hand thumb, divided into two stages, fixed pain and variable pain. The two local Research Ethics Committees (Ethics Committee from Universidade Federal de Sao Paulo- Brazil, process number 0688/11, on July 1st, 2011 and Ethics Committee from Hospital Israelita Albert Einsten - Brazil, process number 1673, on October 19th, 2011) approved the study. Results: The idiopathic musculoskeletal pain (IMP) group showed a reduced threshold for pain (3.7 kg/cm(2) versus 4. 45 kg/cm2, p = 0.005). Control group presented increased bain activation when compared to IMP group in the following areas: thalamus (p = 0.00001), precentral gyrus (p = 0.0004) and middle frontal gyrus (p = 0.03). In intragroup analysis, IMP group showed greater brain activation during the unpredictable stimuli of the variable pain stage, especially in the lingual gyrus (p = 0.0001), frontal lobe (p = 0.0001), temporal gyrus (p = 0.0001) and precentral gyrus (p = 0.03), when compared to predictable stimulus of fixed pain. The same intragroup analysis with the control group showed greater activation during the unpredictable stimuli in regions of the precentral gyrus (p = 0.0001), subcallosal area (p = 0.0001), right and left occipital fusiform gyrus (p = 0.0001; (p = 0.0007), middle gyrus (p = 0.01) and precuneus p = (0.02). Conclusion: Adolescents with idiopathic musculoskeletal pain (IMP) tend to request higher brain function in cognitive-emotional areas when interpreting unpredictable sensory-perceptual situations. Therefore, it is assumed that this difference in pain processing in adolescents with IMP make the subjective experience of pain something more intense and unpleasant.Hospital Israelita Albert EinsteinCAPES (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior)Univ Fed Sao Paulo, Escola Paulista Med, Dept Pediat, Researcher Rheumatol Sect, Sao Paulo, BrazilHosp Israelita Albert Einstein, Brain Inst, Sao Paulo, BrazilHosp Israelita Albert Einstein, Dept Diagnost Imaging, Sao Paulo, BrazilHosp Israelita Albert Einstein, Brain Inst, Sao Paulo, BrazilHosp Israelita Albert Einstein, Sao Paulo, BrazilUniv Minho, Braga, PortugalUniv Fed Sao Paulo, Escola Paulista Medicina, Dept Pediat, Pediat Rheumatol Unit, Rua Borges Lagoa 802,Vila Clementino, BR-04038002 Sao Paulo, SP, BrazilHosp Israelita Albert Einstein, Dept Pediat, Rua Borges Lagoa 802,Vila Clementino, BR-04038002 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Dept Pediat, Researcher Rheumatol Sect, Sao Paulo, BrazilUniv Fed Sao Paulo, Escola Paulista Medicina, Dept Pediat, Pediat Rheumatol Unit, Rua Borges Lagoa 802,Vila Clementino, BR-04038002 Sao Paulo, SP, BrazilWeb of Scienc

Estimation of admixture in two Venezuelan populations using Ancestry Informative Markers and haplogroups of mitochondrial DNA

Los marcadores informativos de ancestralidad (AIM) autosómicos y los del ADN mitocondrial (ADNmt) son muy útiles para identificar el origen y los patrones de migración de las poblaciones. En este trabajo se estimó el mestizaje a partir de siete AIM en 188 individuos venezolanos, 84 del estado Guárico y 104 de la región centro occidental de Venezuela (RCO), se estimó la ancestralidad mitocondrial en el estado Guárico y se compararon ambas poblaciones según su origen y desarrollo histórico. Este estudio representa la primera aproximación a la composición genética de Guárico y es el primer reporte para Venezuela utilizando marcadores tipo AIM. Los resultados revelaron que los aportes amerindio y europeo predominan en estas poblaciones, pero el amerindio es mayor en Guárico (50,57%) que en RCO (44,92%), y el europeo lo es en RCO (38,46% vs. 33,72%). El origen del ADNmt en Guárico es de predominio amerindio (80%), tendencia similar a lo reportado para RCO (75%). El aporte amerindio en Guárico es el más alto reportado para Venezuela. Se concluye que las diferencias encontradas entre ambas muestras podrían deberse a la colonización más temprana de la RCO y a su desarrollo industrial moderado durante el siglo XIX. Así mismo, planteamos que los AIM aquí utilizados lograron una buena discriminación del aporte de los tres grupos ancestrales principales y que su uso simultáneo con polimorfismos de origen uniparental permite obtener, en forma económica, una mejor aproximación genética para explicar la dinámica del proceso de mestizaje que dio origen a la población venezolana actualAncestral informative markers (AIMs) and mitochondrial DNA (mtDNA) are highly useful to understand the origin of populations and their migration patterns. In this work, admixture was estimated using seven AIMs in 188 Venezuelan individuals, 84 belonging to the state of Guárico and 104 belonging to the central western region of Venezuela (RCO). Mitochondrial ancestry of Guárico was also determined, and both populations were compared according to their origin and historical development. This study constitutes the first approximation to the genetic composition of Guárico, and it is the first report for Venezuela using AIMs. The results revealed that Amerindian and European contributions predominate in these populations, but Amerindian is higher in Guárico (50.57%) than in RCO (44.92%), while European is higher in RCO (38.46% vs. 33.72%). In Guárico mtDNA is predominantly Amerindian (80%), as previously reported for RCO (75%). The Amerindian contribution in Guárico is the highest reported for Venezuela. We conclude that the differences found between both samples could be due to an earlier colonization of RCO and to its moderate industrial development during the nineteenth century. We also conclude that the AIMs used here made a good differentiation of the contribution of the three main ancestral groups at a relatively low cost, so that their use, together with polymorphisms of uniparental origin, allows a better genetic approach to explaining the dynamics of the mixing process giving rise to the current Venezuelan population.Asociación de Antropología Biológica de la República Argentin

Transcriptional Profile and Structural Conservation of SUMO-Specific Proteases in Schistosoma mansoni

Small ubiquitin-related modifier (SUMO) is involved in numerous cellular processes including protein localization, transcription, and cell cycle control. SUMOylation is a dynamic process, catalyzed by three SUMO-specific enzymes and reversed by Sentrin/SUMO-specific proteases (SENPs). Here we report the characterization of these proteases in Schistosoma mansoni. Using in silico analysis, we identified two SENPs sequences, orthologs of mammalian SENP1 and SENP7, confirming their identities and conservation through phylogenetic analysis. In addition, the transcript levels of Smsenp1/7 in cercariae, adult worms, and in vitro cultivated schistosomula were measured by qRT-PCR. Our data revealed upregulation of the Smsenp1/7 transcripts in cercariae and early schistosomula, followed by a marked differential gene expression in the other analyzed stages. However, no significant difference in expression profile between the paralogs was observed for the analyzed stages. Furthermore, in order to detect deSUMOylating capabilities in crude parasite extracts, SmSENP1 enzymatic activity was evaluated using SUMO-1-AMC substrate. The endopeptidase activity related to SUMO-1 precursor processing did not differ significantly between cercariae and adult worms. Taken together, these results support the developmentally regulated expression of SUMO-specific proteases in S. mansoni

NEDD8 conjugation in Schistosoma mansoni : genome analysis and expression profiles.

NEDD8 is an ubiquitin-like molecule that covalently binds to target proteins through an enzymatic cascade analogous to ubiquitylation. This modifier is known to bind to p53 and p73, as well as all Cullin family proteins, which are essential components of Skp1/Cul-1/F-box protein (SCF)-like Ub ligase complexes. Here, we focused on a genomic analysis of the genes involved in the NEDD8 conjugation pathway in Schistosoma mansoni. The results revealed seven genes related to NEDD8 conjugation that are conserved in Schistosoma japonicum, Caenorhabditis elegans, Drosophila melanogaster and Homo sapiens. We performed quantitative RT-PCR (qRT-PCR), which showed differential profiles for Smnedd8, Smapp1, Smuba3, Smube2f, Smdcn1, Smrbx and Smsenp8 throughout the life cycle of S. mansoni. Upregulation was observed in 3-day-old schistosomula and adult worms for all analysed genes. We also analysed the transcription levels of Cullin family members Smp63 and Smp73, and observed upregulation in early schistosomula, while cercariae and adult worms showed expression levels similar to one another. Taken together, these results suggest that the NEDDylation/ DeNEDDylation pathway controls important cellular regulators during worm development from cercariae to schistosomula and, finally, to adult

Exposure to trauma-relevant pictures is associated with tachycardia in victims who had experienced an intense peritraumatic defensive response : the tonic immobility.

Tonic immobility is an involuntary, last-ditch defensive reaction characterized by physical inactivity in a context of inescapable threat that has been described in many species, including humans. The occurrence of this defensive response is a predictor of the severity of psychiatric disorders and may be considered as an index of an intense reaction to a traumatic event. Here, we investigated whether the retrospective reports of peritraumatic tonic immobility reaction in participants exposed to a traumatic event would modify their cardiac responses to pictures related to their trauma. Using a questionnaire of life-threating events, we selected students who experienced violent crime as their most intense trauma and students who had never experienced a violent crime trauma, but experienced other traumatic events. All participants completed a questionnaire that estimated the intensity of tonic immobility during their most intense trauma. Electrocardiographic recordings were collected during exposure to pictures. Participants viewed emotional pictures (human attack with guns) and neutral pictures. These emotional stimuli were selected to be trauma-relevant to the violent crime group and non trauma-relevant to the no violent crime trauma group. Violent crime group showed a positive correlation between heart rate changes after viewing trauma-related pictures and tonic immobility scores. We observed that low tonic immobility scores were associated with bradycardia and high scores with tachycardia in response to trauma-relevant pictures. For the no violent crime group, no significant correlation was detected. These results suggest that the relevance of the stimuli and the magnitude of the defensive response during a previous trauma event were important factors triggering more intense defensive responses