Proteolytic degradation of atrial sarcomere proteins underlies contractile defects in atrial fibrillation.

Atrial fibrillation (AFib) is the most common cardiac rhythm disturbance, often treated via electrical cardioversion. Following rhythm restoration, a period of depressed mechanical function known as atrial stunning occurs, suggesting that defects in contractility occur in AFib and are revealed upon restoration of rhythm. This project aims to define the contractile remodeling that occurs in AFib. To assess contractile function, we used a canine atrial tachypacing model of induced AFib. Mass spectrometry analysis showed dysregulation of contractile proteins in samples from AFib compared to sinus rhythm atria. Atrial cardiomyocytes showed reduced force of contraction, decreased resting tension, and increased calcium sensitivity in skinned single cardiomyocyte studies. These alterations correlated with degradation of myofilament proteins including myosin heavy chain altering force of contraction, titin altering resting tension, and TnI altering calcium sensitivity. We measured degradation of other myofilament proteins including cMyBP-C and actininshowing significant degradation in the AFib samples compared to sinus rhythm atria. Many of the protein degradation products appeared as discrete cleavage products that are generated by calpain proteolysis. We assessed calpain activity and found it to be significantly increased. These results provide an understanding of the contractile remodeling that occurs in AFib and provide insight into the molecular explanation for atrial stunning and the increased risk of atrial thrombus and stroke in AFib.

Proteolytic degradation of atrial sarcomere proteins underlies contractile defects in atrial fibrillation.

Aims: Atrial fibrillation (AFib) is the most common cardiac rhythm disturbance. Treatment of AFib involves restoration of the atrial electrical rhythm. Following rhythm restoration, a period of depressed mechanical function known as atrial stunning occurs that involves decreased blood flow velocity and reduced atrial contractility. This suggests that defects in contractility occur in AFib and are revealed upon restoration of rhythm. The aim of this project is to define the contractile remodeling that occurs in AFib. Methods and Results: To assess contractile function, we used a canine atrial tachypacing model of induced AFib. Mass spectrometry analysis showed dysregulation of contractile proteins in samples from AFib compared to sinus rhythm atria. Atrial cardiomyocytes showed reduced force of contraction in skinned single cardiomyocyte calcium-force studies. There were no significant differences in myosin heavy chain isoform expression. Resting tension is decreased in the AFib samples correlating with reduced full-length titin in the sarcomere. We measured degradation of other myofilament proteins including cMyBP-C, actinin, and cTnI, showing significant degradation in the AFib samples compared to sinus rhythm atria. Many of the protein degradation products appeared as discrete cleavage products that are generated by calpain proteolysis. We assessed calpain activity and found it to be significantly increased. Skinned cardiomyocytes from AFib atria showed decreased troponin I phosphorylation, consistent with the increased calcium sensitivity that was found within these cardiomyocytes. Conclusions: With these results it can be concluded that AFib causes alterations in contraction that can be explained by both molecular changes occurring in myofilament proteins and overall myofilament protein degradation. These results provide an understanding of the contractile remodeling that occurs in AFib and provides insight into the molecular explanation for atrial stunning and the increased risk of atrial thrombus and stroke in AFib.

Second-order nonlinear optical coefficients of the monoclinic crystal BaGa4Se7.

We characterize the magnitude and relative signs of the second-order nonlinear optical coefficients of the biaxial crystal BaGa4Se7 (BGSe) combining measurements of phase-matched and non-phase-matched second-harmonic generation at different wavelengths using slabs and a sphere.

Contribuições da psicologia para a relação professor-aluno / Contribuciones de la psicología a la relación maestro-estudiante / Contributions of psychology to the teacher-student relationship

As concepções de diferentes abordagens da psicologia - e de outros campos de saber - sobre como o ser humano conhece podem contribuir para a compreensão da relação que se estabelece entre adultos e crianças, adultos e adolescentes e adultos e adultos nos diversos segmentos educacionais, da creche à universidade. Trata-se de artigo de revisão de literatura que tem por objetivo explicitar os principais conceitos das teorias de Jean Piaget, Lev Vigotski, Wilhelm Reich e Martin Buber, buscando com isso elementos que ajudem na compreensão da complexa relação professor-aluno, que vai além da sala de aula, rompendo com uma concepção de ensino como transferência de conhecimento. Essa relação se constrói em um determinado tempo e espaço, marcados por valores, ideologias, normas e discursos. As contribuições da psicologia para a educação devem caminhar no sentido de ajudar a compreender as complexas interações que se estabelecem no interior das instituições educativas, contextualizando os fenômenos e abordando-os no âmbito das relações entre as pessoas, considerando a complexidade que envolve essa discussão.(AU)

The views of different approaches of psychology - and of other fields of knowledge - about the way human being acquires knowledge, may contribute to the comprehension of the relation that is established between adults and kids, adults and teenager and adults and adults in the many educational segments, from day care to university. The goal of the article is to explain the main concepts of theories of Jean Piaget, Lev Vigotski, Wilhelm Reich and Martin Buber, seeking with this, elements that help in the comprehension of the complex teacher-student relationship that goes beyond the classroom and disrupting with a view of education as transfer of knowledge. This relationship is built in a given time and space, marked by values, ideologies, norms and discourses. The contributions of psychology to education must move towards helping to understand the complex interactions established within educational institutions, contextualizing the phenomena and addressing them in the context of relationships between people, considering the complexity involved in this discussion.(AU)

Concepciones de diferentes enfoques de la psicología - y otras áreas del conocimiento - acerca de cómo el ser humano conoce, pueden contribuir a la comprensión de la relación que se establece entre adultos y niños, adultos y adolescentes y adultos y adultos en los diferentes segmentos educativos, desde la guardería a la universidad. Se trata de un artículo de revisión de la literatura cuyo objetivo es explicar los principales conceptos de las teorías de Jean Piaget, Lev Vigotski, Wilhelm Reich y Martin Buber, buscando elementos que contribuyan a la comprensión de la compleja relación profesor-alumno, que va más allá de la clase, rompiendo con una concepción de la enseñanza como transferencia de conocimiento. Esa relación se construye en un tiempo y un espacio determinados, marcados por valores, ideologías, normas y discursos. Las contribuiciones de la psicología a la educación deben ayudar a comprender las complejas interacciones que se establecen al interior de las instituciones educativas, contextualizando los fenómenos en el ámbito de las relaciones entre las personas, considerando la complejidad que involucra esa discusión.(AU)

Development and experimental demonstration of negative first-order quasi-phase matching in a periodically poled Rb-doped KTiOPO4 crystal.

We worked on a new scheme of quasi-phase matching (QPM) based on the negative first order of the spatial modulation of the sign of the second-order nonlinearity. Applying this scheme in the case of angular-QPM (AQPM) in a biaxial crystal reveals new directions of propagation for efficient parametric frequency conversion as well as "giant" spectral acceptances. The experimental validation is performed in a periodically poled rubidium-doped KTiOPO4 biaxial crystal. This new approach naturally extends to other periodically poled uniaxial crystals such as periodically poled LiNbO3.

Lack of virologic suppression is associated with lower HIV-related disclosure stigma in people living with HIV.

Stigma remains a leading barrier to HIV care. To determine the influence of disclosure stigma (DS), fear of disclosing one's serostatus, on virologic suppression, a cross-sectional study was performed at the largest publicly-funded HIV clinic in South Texas. A survey was administered to participants who were: ≥18 years old, living with HIV, and receiving antiretroviral therapy. Surveys included demographics, adherence questionnaire, and a validated HIV-stigma scale with DS as the sum of 10 items ranked 0-3, with score of 30 indicating highest stigma. The primary outcome was lack of virologic suppression (LOVS): most recent HIV-1 RNA > 20 copies/ml. A bivariate analyses examined predictors of DS, dichotomized at the median. Depression score, perceived stress, and lack of friend/family support were associated with DS. Logistic regression models examined the relationship between DS, as a continuous variable, and LOVS. For 275 participants (69% Hispanic), median DS score was 18.5. DS was significantly inversely associated with LOVS (aOR 0.94 per 1 scale point; CI 0.89, 0.99) after adjustment for age, gender/sexual orientation, race/ethnicity, and drug use. The unanticipated inverse association between DS and LOVS highlights the complexity of this relationship. However, the balance of data in this cohort demonstrate an overall negative impact of DS.

Mulinane and Azorellane Diterpenoid Biomarkers by GC-MS from a Representative Apiaceae (Umbelliferae) Species of the Andes.

Extracts of bled resin from Azorella compacta, of the Azorelloideae family from the Andes (>4000 m), were analyzed by gas chromatography-mass spectrometry. The mass spectra of the dominant compounds of the resin and its hydrogenation products were documented. The most abundant compounds were oxygenated diterpenoids, namely mulinadien-20-oic (Δ11,13 and Δ11,14) acids, azorell-13-en-20-oic acid, 13α,14ß-dihydroxymulin-11-en-20-oic acid, and azorellanol, with a group of azorellenes and mulinadienes. The mass spectra of the novel diterpenoid hydrocarbons with the azorellane and mulinane skeletons were also presented. This study documents the molecular diversity of these diterpenoid classes, and could be of great utility for future organic geochemical, environmental, archeological, pharmaceutical, and forensic chemistry studies.

Validation of the angular quasi-phase-matching theory for the biaxial optical class using PPRKTP.

We report the first experimental validation of angular quasi-phase-matching (AQPM) theory in a biaxial crystal by performing second-harmonic generation (SHG) in the periodically-poled Rb-doped KTiOPO4 (PPRKTP) crystal cut as a sphere. Both AQPM and birefringence phase-matching (BPM) angles were measured thanks to a Kappa circle.

Formação humana, visão de mundo, diálogo e educação: a atualidade de paulo freire e martin buber / Human formation, world vision, dialogue and education: the present relevance of paulo freire and martin buber

RESUMO: Este artigo discute questões contemporâneas da educação no que se refere às relações entre professores e alunos e à formação, a partir das teorias de Paulo Freire e de Martin Buber. Inicialmente, o texto explicita a aproximação entre a teoria de Freire e Buber. Em seguida, destaca aspectos fundantes da obra dos dois pensadores por favorecerem uma formação que se situe e que atue para o diálogo, contra a desumanização e qualquer tipo de humilhação, discriminação ou exclusão. Ao final, sintetiza contribuições de Paulo Freire e Martin Buber para uma educação voltada para a formação de comunidade e que seja crítica, criativa, dialógica. Nas considerações finais, fica evidenciada a atualidade de Freire e Buber, seu legado teórico para ações práticas e políticas.

ABSTRACT: This article discusses contemporary issues of education regarding the relationship between teachers and students and training/education, from the theories of Paulo Freire and Martin Buber. Initially, the text explains the proximity between the theories of Paulo Freire and Martin Buber. Next, it highlights fundamental aspects of the works of the two thinkers for favoring training/education that lies in and acts for dialogue, against the dehumanization and any kind of humiliation, discrimination or exclusion. Finally, it summarizes Freire's and Buber's contribution to an education focused on community training/education and that is critical, creative, dialogical. In the final considerations, the present relevance of Martin Buber and Paulo Freire, their theoretical legacy for practical and political actions is evident.

Expression of the Aeluropus littoralis AlSAP Gene Enhances Rice Yield under Field Drought at the Reproductive Stage.

We evaluated the yields of Oryza sativa L. 'Nipponbare' rice lines expressing a gene encoding an A20/AN1 domain stress-associated protein, AlSAP, from the halophyte grass Aeluropus littoralis under the control of different promoters. Three independent field trials were conducted, with drought imposed at the reproductive stage. In all trials, the two transgenic lines, RN5 and RN6, consistently out-performed non-transgenic (NT) and wild-type (WT) controls, providing 50-90% increases in grain yield (GY). Enhancement of tillering and panicle fertility contributed to this improved GY under drought. In contrast with physiological records collected during previous greenhouse dry-down experiments, where drought was imposed at the early tillering stage, we did not observe significant differences in photosynthetic parameters, leaf water potential, or accumulation of antioxidants in flag leaves of AlSAP-lines subjected to drought at flowering. However, AlSAP expression alleviated leaf rolling and leaf drying induced by drought, resulting in increased accumulation of green biomass. Therefore, the observed enhanced performance of the AlSAP-lines subjected to drought at the reproductive stage can be tentatively ascribed to a primed status of the transgenic plants, resulting from a higher accumulation of biomass during vegetative growth, allowing reserve remobilization and maintenance of productive tillering and grain filling. Under irrigated conditions, the overall performance of AlSAP-lines was comparable with, or even significantly better than, the NT and WT controls. Thus, AlSAP expression inflicted no penalty on rice yields under optimal growth conditions. Our results support the use of AlSAP transgenics to reduce rice GY losses under drought conditions.

Combining Image Analysis, Genome Wide Association Studies and Different Field Trials to Reveal Stable Genetic Regions Related to Panicle Architecture and the Number of Spikelets per Panicle in Rice.

Number of spikelets per panicle (NSP) is a key trait to increase yield potential in rice (O. sativa). The architecture of the rice inflorescence which is mainly determined by the length and number of primary (PBL and PBN) and secondary (SBL and SBN) branches can influence NSP. Although several genes controlling panicle architecture and NSP in rice have been identified, there is little evidence of (i) the genetic control of panicle architecture and NSP in different environments and (ii) the presence of stable genetic associations with panicle architecture across environments. This study combines image phenotyping of 225 accessions belonging to a genetic diversity array of indica rice grown under irrigated field condition in two different environments and Genome Wide Association Studies (GWAS) based on the genotyping of the diversity panel, providing 83,374 SNPs. Accessions sown under direct seeding in one environement had reduced Panicle Length (PL), NSP, PBN, PBL, SBN, and SBL compared to those established under transplanting in the second environment. Across environments, NSP was significantly and positively correlated with PBN, SBN and PBL. However, the length of branches (PBL and SBL) was not significantly correlated with variables related to number of branches (PBN and SBN), suggesting independent genetic control. Twenty- three GWAS sites were detected with P ≤ 1.0E-04 and 27 GWAS sites with p ≤ 5.9E-04. We found 17 GWAS sites related to NSP, 10 for PBN and 11 for SBN, 7 for PBL and 11 for SBL. This study revealed new regions related to NSP, but only three associations were related to both branching number (PBN and SBN) and NSP. Two GWAS sites associated with SBL and SBN were stable across contrasting environments and were not related to genes previously reported. The new regions reported in this study can help improving NSP in rice for both direct seeded and transplanted conditions. The integrated approach of high-throughput phenotyping, multi-environment field trials and GWAS has the potential to dissect complex traits, such as NSP, into less complex traits and to match single nucleotide polymorphisms with relevant function under different environments, offering a potential use for molecular breeding.

Ocular Surface as Barrier of Innate Immunity.

Sight is one of the most important senses that human beings possess. The ocular system is a complex structure equipped with mechanisms that prevent or limit damage caused by physical, chemical, infectious and environmental factors. These mechanisms include a series of anatomical, cellular and humoral factors that have been a matter of study. The cornea is not only the most powerful and important lens of the optical system, but also, it has been involved in many other physiological and pathological processes apart from its refractive nature; the morphological and histological properties of the cornea have been thoroughly studied for the last fifty years; drawing attention in its molecular characteristics of immune response. This paper will review the anatomical and physiological aspects of the cornea, conjunctiva and lacrimal apparatus, as well as the innate immunity at the ocular surface.

Interações, práticas, políticas e modos de gestão: o referencial histórico cultural nas teses e dissertações do grupo INFOC de 2003 a 2013 / Interactions, practices, policies and methods of management: the benchmark in cultural history of theses and dissertations in INFOC group 2003-2013

Tendo em perspectiva que o pesquisador que pretende investigar as crianças como sujeitos deve levar em conta quem são as crianças, como participam do processo de produção dos conhecimentos, que significados produzem sobre a realidade que as cerca, este artigo faz o levantamento da presença de Vigotski na produção acadêmica do grupo INFOC – Infância Formação e cultura, envolvendo pesquisas no período de 2003 a 2013. De 30 pesquisas, oito trazem Vigotski como referência para analisar interações e práticas entre crianças e destas com os adultos em creches, pré-escolas. Um estudo se realiza em um museu e dois abordam políticas de educação infantil e formação de profissionais. Este artigo faz também o levantamento dos livros utilizados como fonte de pesquisa, bem como que conceitos estão presentes. Com este levantamento, pretendeu-se verificar como o enraizamento das ideias de Vigotski, enquanto um dos autores de referência desse grupo, se ramifica nas pesquisas individuais.

The researcher who intends to investigate children as subjects must consider who they are, how do they participate of the knowledge production process and which meanings do they produce about reality. In this perspective, this paper presents a survey of Vigotski’s appearance in the academic production of INFOC - Infância, Formação e Cultura, between 2003 and 2013. Considering thirty thesis and dissertations, in eight we found Vigotski as a reference to analize interactions and practices between children and between children and adults in kindergartens and pre-schools. One study takes place in a museum and two are about policies for Early Education and teacher´s training. This paper also analizes which of Vigotski’s books and concepts were taken as theorical sources. This survey focused on how the ideas of Vigotski, as an reference author of INFOC group, is present in each of the individuals researches.

Laser operation of Yb3+ in the acentric RbTiOPO4 codoped with Nb5+.

We report on continuous-wave lasing of Yb(3+) at room temperature in the noncentrosymmetric RbTiOPO(4) crystal, codoped with Nb(5+), for all three possible polarizations. A maximum output power of 154 mW at 1050 nm was obtained for an absorbed power of 386 mW. The highest slope efficiency reached approximately 60% and the lowest threshold (with respect to the absorbed power) was 18 mW. The laser was tunable from 1009 to 1081 nm.

Yb(3+) spectroscopy in (Nb or Ta):RbTiOPO(4) single crystals for laser applications.

Single crystals of Yb:RbTiOPO(4) codoped with Nb(5+) or Ta(5+) were grown by the top seeded solution growth slow-cooling technique. The ytterbium concentration in the crystals varies as a function of the molar ratio of the precursor oxides and of the codopant, reaching a maximum value of 1.9x10(20) Yb(3+) ions/cm(3). The broad band near 1 mum in absorption and emission spectra at room temperature is due to the large splitting of the Yb(3+) ground state. The ytterbium (2)F(5/2) level radiative lifetime in Nb:RbTiOPO(4) (tau(rad) = 2.7 ms), was calculated and then compared to the measured fluorescence decay time (tau(em) = 2.2 ms), giving an intrinsic quantum efficiency of 81%. To evaluate the potentiality of these crystals for self-frequency doubling, preliminary results of Yb(3+) laser operation and fundamental wavelength measurements for type-II non-critical second harmonic generation ( lambda(NCPM)) are also reported.