Morphology and flexibility of graphene and few-layer graphene on various substrates

We report on detailed microscopy studies of graphene and few-layer-graphene produced by mechanical exfoliation on various semi-conducting substrates. We demonstrate the possibility to prepare and analyze graphene on (001)-GaAs, manganese p-doped (001)-GaAs and InGaAs substrates. The morphology of graphene on these substrates was investigated by scanning electron and atomic force microscopy and compared to layers on silicon oxide. It was found that graphene sheets strongly follow the texture of the sustaining substrates independent on doping, polarity or roughness. Furthermore resist residues exist on top of graphene after a lithographic step. The obtained results provide the opportunity to research the graphene-substrate interactions

Gene-Targeting zur Herstellung einer IgE überexprimierenden Maus

Die hier vorliegende Arbeit stellt ein neues Mausmodell vor, mit dem der Einfluß von IgE in der Entstehung einer Allergie und die Folgen vermehrter IgE-Produktion in-vivo untersucht werden können. Erreicht wurde dies durch eine definierte Mutation im Erbgut von Mäusen. Mittels homologer Rekombination wurde durch ein knock-in-Verfahren eines der beiden g1-Allele im Immunglobulingenlocus durch die Sequenz, die für den IgE-Isotyp codiert, ersetzt

As Percepções políticas da elite econômica-representativa do cooperativismo agroindustrial

Orientador: Prof. Dr. Paulo R. Neves CostaTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Humanas, Programa de Pós-Graduação em Ciência Política. Defesa : Curitiba, 19/03/2019Inclui referências: p. 195-211Resumo: O presente trabalho se insere nos estudos de elite e cultura política, ao abordar as características dos presidentes de grandes cooperativas agroindustriais e suas concepções acerca da política, especificamente: a Democracia, a relação entre Democracia e Economia e uma autoavaliação de sua Ação Política. Pela utilização da prosopografia e do método qualitativo indutivo de Análise do Padrão Coletivo de Interpretação/significação (Deutungsmusteranalyse - DMA), foi materializado um tipo ideal morfológico e atitudinal dessa elite. A conjugação dos dois métodos não guarda entre si uma relação de causa e efeito. Seu tipo ideal pode ser resumido como um conjunto de homens brancos, brasileiros, de meia idade, com longas carreiras únicas na cooperativa, que atuam politicamente através da entidade de representação, tendo por base uma orientação da ação movida por uma mentalidade coletiva de ator econômico. Aderem à Democracia porque são partidários da livre economia, meio para garantir o valor do empreendedorismo. Constatamos, também, elementos singulares que caracterizam a elite cooperativista distinguindo-a da elite empresarial. Por exemplo, a sobreposição de duas dimensões: a econômica, enquanto controladores de grandes empreendimentos econômicos e a representativa, dado que também ocupam postos de direção na entidade de representação política da categoria econômica do cooperativismo. A caracterização de uma elite econômica que age politicamente e é pouco estudada fornece dados para comparação e aprofundamento com outros trabalhos da Ciência Política; a reconstrução dos estoques de conhecimento coletivos permitem identificar os vetores da orientação da ação dos atores, produzindo dados além das justificativas, acarretando ganhos aos estudos de cultura política de elites. Palavras-chaves: Cooperativas Agroindustriais; Cooperativismo; Cultura política; OCEPAR; Elite cooperativista; Elite econômica e política.Abstract: This work falls within the studies of political elite and culture, approaching the traits of the presidents of big agri-industrial co-operatives and their notions on politics, specifically: Democracy, relation between Democracy and Economy and self-assesment of their political action. By usage of prosopography and the inductive qualitative method of Collective Mindset Analysis (Deutungsmusteranalyse - DMA), an ideal morphologic and atitudinal type of such elite was embodied. The combination of both methods does not hold within it a cause-and-effect relation. Its ideal type may be summarized as a set of white males, Brazilians, middle-aged, with long and single careers in the co-operative, who act politically through the representation entity, based on an orientation of the action moved by a collective mindset of economic player. They adhere to Democracy because they advocate free economy, the means to ensure the value of entrepreneurship. We also noted singular elements that characterize this elite, distinguishing it from the corporate elite. For example, the overlapping of two dimensions: the economic, as holders of big economic enterprises, and the representative, given that they also take management seats with the political representation entity of cooperativism's economic class. The characterization of an economic elite that acts politically and is undereducated provides data for comparison and deepening with other studies of Political Science; the reconstruction of collective knowledge inventories allows identification of the vectors of the players' orientation of action, producing data beyond the justifications, entailing gains to the studies of political culture of elites. Keywords: Agro-industrial Co-operatives; Cooperativism; Political culture; OCEPAR; Cooperativism Elite; Economic and political elite

Geometry-sensitive protrusion growth directs confined cell migration

The migratory dynamics of cells can be influenced by the complex micro-environment through which they move. It remains unclear how the motility machinery of confined cells responds and adapts to their micro-environment. Here, we propose a biophysical mechanism for a geometry-dependent coupling between the front of the cell and the nucleus that leads to directed migration. We apply our model to geometry-guided cell migration to obtain insights into the origin of directed migration on asymmetric adhesive micro-patterns and the polarization enhancement of cells observed under strong confinement. Remarkably, for cells that can choose between channels of different size, our model predicts an intricate dependence for cellular decision making as a function of the two channel widths, which we confirm experimentally

Modulation of the Hypothalamic Nutrient Sensing Pathways by Sex and Early-Life Stress

There are sex differences in metabolic disease risk, and early-life stress (ES) increases the risk to develop such diseases, potentially in a sex-specific manner. It remains to be understood, however, how sex and ES affect such metabolic vulnerability. The hypothalamus regulates food intake and energy expenditure by sensing the organism’s energy state via metabolic hormones (leptin, insulin, ghrelin) and nutrients (glucose, fatty acids). Here, we investigated if and how sex and ES alter hypothalamic nutrient sensing short and long-term. ES was induced in mice by limiting the bedding and nesting material from postnatal day (P)2-P9, and the expression of genes critical for hypothalamic nutrient sensing were studied in male and female offspring, both at P9 and in adulthood (P180). At P9, we observed a sex difference in both Ppargc1a and Lepr expression, while the latter was also increased in ES-exposed animals relative to controls. In adulthood, we found sex differences in Acacb, Agrp, and Npy expression, whereas ES did not affect the expression of genes involved in hypothalamic nutrient sensing. Thus, we observe a pervasive sex difference in nutrient sensing pathways and a targeted modulation of this pathway by ES early in life. Future research is needed to address if the modulation of these pathways by sex and ES is involved in the differential vulnerability to metabolic diseases

O ESTADO E A AÇÃO POLÍTICA ORGANIZADA: COOPERATIVISMO AGROPECUÁRIO NO ESTADO DO PARANÁ (1907-1988)

O cooperativismo agropecuário ocupa papel relevante na economia do Paraná, alcançando elevado percentual no PIB estadual, bem como respeitável número de participação humana (OCEPAR, 2013). Em análise histórica do “movimento cooperativo” notamos a presença de intensa tutela estatal nas cooperativas até 1988. Para entendimento da dimensão e influencia do Estado em um setor privado da sociedade, procedemos análise das ações estatais, incluindo a atividade legislativa, no período de (1907-1988). Comprovamos a influencia do Estado desde a formação dos grupos organizados cooperativos até a o apoio à estruturação da entidade de representação, sendo esta presença do Estado elemento essencial na arquitetura que resultou a estruturação do “sistema cooperativo” paranaense da atualidade. Metodologicamente dividimos a análise em quatro períodos históricos principais: (i) definição legal das primeiras organizações cooperadas (1907-1938); (ii) estruturação dos grupos cooperativos (1944-1964); (iii) institucionalização da entidade de representação (1965-1971); (iv) regulação do cooperativismo – criação e extinção da tutela estatal nas organizações cooperativas (1971-1988). As conclusões preliminares demonstram que o cooperativismo passou por diversas fases de desenvolvimento até alcançar o pleno estabelecimento de uma organização liberta do Estado com ação em prol dos interesses de seus membros (OLSON, 2011; MANCUSO, 2007; COSTA, 2012).

Effects of early-life stress on peripheral and central mitochondria in male mice across ages

Exposure to early-life stress (ES) increases the vulnerability to develop metabolic diseases as well as cognitive dysfunction, but the specific biological underpinning of the ES-induced programming is unknown. Metabolic and cognitive disorders are often comorbid, suggesting possible converging underlying pathways. Mitochondrial dysfunction is implicated in both metabolic diseases and cognitive dysfunction and chronic stress impairs mitochondrial functioning. However, if and how mitochondria are impacted by ES and whether they are implicated in the ES-induced programming remains to be determined. ES was applied by providing mice with limited nesting and bedding material from postnatal day (P)2-P9, and metabolic parameters, cognitive functions and multiple aspects of mitochondria biology (i.e. mitochondrial electron transport chain (ETC) complex activity, mitochondrial DNA copy number, expression of genes relevant for mitochondrial function, and the antioxidant capacity) were studied in muscle, hypothalamus and hippocampus at P9 and late adulthood (10–12 months of age). We show that ES altered bodyweight (gain), adiposity and glucose levels at P9, but not in late adulthood. At this age, however, ES exposure led to cognitive impairments. ES affected peripheral and central mitochondria in an age-dependent manner. At P9, both muscle and hypothalamic ETC activity were affected by ES, while in hippocampus, ES altered the expression of genes involved in fission and antioxidant defence. In adulthood, alterations in ETC complex activity were observed in the hypothalamus specifically, whereas in muscle and hippocampus ES affected the expression of genes involved in mitophagy and fission, respectively. Our study demonstrates that ES affects peripheral and central mitochondria biology throughout life, thereby uncovering a converging mechanism that might contribute to the ES-induced vulnerability for both metabolic diseases and cognitive dysfunction, which could serve as a novel target for intervention.</p

Assaying microglia functions in vitro

Microglia, the main immune modulators of the central nervous system, have key roles in both the developing and adult brain. These functions include shaping healthy neuronal networks, carrying out immune surveillance, mediating inflammatory responses, and disposing of unwanted material. A wide variety of pathological conditions present with microglia dysregulation, highlighting the importance of these cells in both normal brain function and disease. Studies into microglial function in the context of both health and disease thus have the potential to provide tremendous insight across a broad range of research areas. In vitro culture of microglia, using primary cells, cell lines, or induced pluripotent stem cell derived microglia, allows researchers to generate reproducible, robust, and quantifiable data regarding microglia function. A broad range of assays have been successfully developed and optimised for characterizing microglial morphology, mediation of inflammation, endocytosis, phagocytosis, chemotaxis and random motility, and mediation of immunometabolism. This review describes the main functions of microglia, compares existing protocols for measuring these functions in vitro, and highlights common pitfalls and future areas for development. We aim to provide a comprehensive methodological guide for researchers planning to characterise microglial functions within a range of contexts and in vitro models