Does Cell Lineage in the Developing Cerebral Cortex Contribute to its Columnar Organization?

Since the pioneer work of Lorente de Nó, Ramón y Cajal, Brodmann, Mountcastle, Hubel and Wiesel and others, the cerebral cortex has been seen as a jigsaw of anatomic and functional modules involved in the processing of different sets of information. In fact, a columnar distribution of neurons displaying similar functional properties throughout the cerebral cortex has been observed by many researchers. Although it has been suggested that much of the anatomical substrate for such organization would be already specified at early developmental stages, before activity-dependent mechanisms could take place, it is still unclear whether gene expression in the ventricular zone (VZ) could play a role in the development of discrete functional units, such as minicolumns or columns. Cell lineage experiments using replication-incompetent retroviral vectors have shown that the progeny of a single neuroepithelial/radial glial cell in the dorsal telencephalon is organized into discrete radial clusters of sibling excitatory neurons, which have a higher propensity for developing chemical synapses with each other rather than with neighboring non-siblings. Here, we will discuss the possibility that the cell lineage of single neuroepithelial/radial glia cells could contribute for the columnar organization of the neocortex by generating radial columns of sibling, interconnected neurons. Borrowing some concepts from the studies on cell–cell recognition and transcription factor networks, we will also touch upon the potential molecular mechanisms involved in the establishment of sibling-neuron circuits

Attitude dynamics and stability of a simple solar photon thruster

This paper is dedicated to the development of a model of the attitude dynamics for a nonideal Simple Solar Photon Thruster (SSPT) and to the analysis of sailcraft motions with respect to their centre of mass. Derivation of the expressions for force and torque due to solar radiation that is valid for the case, when there is a misalignment of the SSPT axis with the sun direction, is followed by study of sailcraft dynamics and stability properties. Analysis of stability shows that an ideally reflecting sail is unstable, while for a sailcraft with nonideal collector, the symmetry axis is stable with respect to the Sun direction for large variety of system parameters. The motion around symmetry axis is always unstable and requires an active stabilizer.FCT, COMPETE, QREN, FEDE

Employment, Careers and Productivity: Lessons from Three E.U. Countries

This thesis is composed of four empirical studies which use data from Portugal, the United Kingdom and Germany to examine four topical aspects of employment, careers and productivity in these countries' labour markets. The second chapter studies the impact that a 49.3% change in the legal minimum wage for workers aged 18 and 19 in Portugal had on the wages and employment of this age group of workers. It uses firm-level micro data to compare the employment growth of 18-19 year old workers with employment growth of older workers. It also looks separately at firms more and less likely to be affected by the minimum wage shock. The third chapter studies the impact of foreign direct investment (FDI) on the productivity of domestic firms in the UK. It uses a plant-level panel covering UK manufacturing to find evidence of FDI spillovers. It does so by investigating the correlation between a domestic plant's TFP and the foreign-affiliate share of employment in that plant's industry and, independently, in that plant's region. A number of different specifications are estimated in order to minimise potential endogeneity bias. The fourth chapter estimates returns to job tenure and labour market experience in the United Kingdom and Germany using various methods to correct for heterogeneity and endogeneity biases. It also estimates the returns to tenure and experience by qualification group. Results are interpreted in light of the differences between the two labour market's institutions. The fifth chapter compares returns to tenure and experience in union and non-union jobs in the United Kingdom in the 80s and 90s. It uses longitudinal data and instrumental variables methods to correct for potential individual and job match heterogeneity biases. Returns are also calculated separately for jobs with and without seniority wage scales

Associations of Adiponectin with Adiposity, Insulin Sensitivity, and Diet in Young, Healthy, Mexican Americans and Non-Latino White Adults.

Low circulating adiponectin levels may contribute to higher diabetes risk among Mexican Americans (MA) compared to non-Latino whites (NLW). Our objective was to determine if among young healthy adult MAs have lower adiponectin than NLWs, independent of differences in adiposity. In addition, we explored associations between adiponectin and diet. This was an observational, cross-sectional study of healthy MA and NLW adults living in Colorado (U.S.A.). We measured plasma total adiponectin, adiposity (BMI, and visceral adipose tissue), insulin sensitivity (IVGTT), and self-reported dietary intake in 43 MA and NLW adults. Mean adiponectin levels were 40% lower among MA than NLW (5.8 ± 3.3 vs. 10.7 ± 4.2 µg/mL, p = 0.0003), and this difference persisted after controlling for age, sex, BMI, and visceral adiposity. Lower adiponectin in MA was associated with lower insulin sensitivity (R² = 0.42, p < 0.01). Lower adiponectin was also associated with higher dietary glycemic index, lower intake of vegetables, higher intake of trans fat, and higher intake of grains. Our findings confirm that ethnic differences in adiponectin reflect differences in insulin sensitivity, but suggest that these are not due to differences in adiposity. Observed associations between adiponectin and diet support the need for future studies exploring the regulation of adiponectin by diet and other environmental factors

Argumentación sobre arte: aportes de la retórica al estudio de los argumentos en la crítica de arte

A partir del análisis argumentativo de distintas críticas de arte de circulación académica, se destaca la importancia de integrar aspectos vinculados con el ethos y el pathos en la interpretación de los argumentos. Asimismo, se ilustran las relaciones entre dichos argumentos, las figuras retóricas empleadas y las representaciones sociales que se infieren de los textos estudiados. El trabajo pone en evidencia que cada argumento es portador de una representación del mundo del arte, del rol del crítico y del lugar del público, que el análisis argumentativo elaborado desde la perspectiva retórica permite mostrar

O ofício de traduzir e suas implicações

O tema deste artigo é a tradução com enfoque na literária, pois tem sua complexidade ampliada pela ação conotativa e é a que exige, de quem exerce esse ofício artesanal e artístico, um esforço intelectual maior. Na tradução, as palavras etemas estão amalgamados de subjetividade e ambiguidades, que ensejam a abertura deum leque de interpretações tais, que resultam na difícil tarefa de verter para a língua, que não a do autor, o que esse disse e sentiu. O destaque aqui será para a essência literária: a linguagem poética. É preciso considerar na trajetória deste ofício as diferenças culturais e seus valores e manter particularidades de estilo, sem ocomprometimento do texto original. Ocorre com frequência mostrar-se a tradução impermeável, isto é, impossibilitar a busca do equivalente na língua para a qual se traduz. Cabe então, ao tradutor, agir com eficiência e bom senso para que não seproduzam absurdos tradutórios. O texto reflete também sobre a ética do tradutor e algumas de suas posturas e fatores essenciais, tais como: respeito (com o texto, o autor,o leitor e consigo mesmo), fidedignidade, ampla cultura geral, predisposição àpesquisa e um longo “etecétera”.PALAVRAS-CHAVE: Platero - Transcriar - PesquisaRESUMEN: El tema de este artículo es la traducción con enfoque en la literaria, puestiene su complejidad ampliada por la acción connotativa y es la que exige, de quienejerce ese oficio artesanal y artístico, un mayor esfuerzo intelectual. En la traducción,las palabras y temas se amalgaman de subjetividad y ambigüedades, que admiten la apertura de un abanico de interpretaciones tales, que resultan en la difícil tarea de verter para la lengua, que no la del autor, lo que ése dijo y sintió. Aquí se destaca laesencia literaria: el lenguaje poético. Hay que considerar en la trayectoria de ese oficiolas diferencias culturales y sus valores y así mantener particularidades de estilo, sincomprometer el texto original. Frecuentemente se pone la traducción impermeable, esdecir, imposibilita la búsqueda del equivalente en la lengua para la cual se traduce. Cabe, entonces, al traductor actuar con eficiencia y discernimiento para que no seproduzcan absurdos traductorios. El texto reflexiona también acerca de la ética deltraductor y algunas de sus posturas y factores esenciales, tales como: respeto (con eltexto, el autor, el lector y consigo mismo), fidedignidad, amplia cultura general,predisposición a la investigación y un largo “etecetera”.PALAVRAS CLAVE: Platero - Transcrear - Investigació

Influence of process parameters and initial microstructure on the oxidation resistance of Ti48Al2Cr2Nb coating obtained by laser metal deposition

[EN] Ti6Al4V have been the most important and versatile titanium alloys currently used, due to their excellent combination of low density and good mechanical properties, despite their application temperature being limited to up to 300 °C. In this work, a Ti6Al4V sheet was coated with a Ti48Al2Cr2Nb alloy by laser cladding process, with the process parameters resulting in laser-specific energy densities of 70, 80, 90 and 180 J/mm2, laser power between 600 and 900W and scanning speed of 100 to 300 mm/min. In order to analyze the oxidation resistance at elevated temperature, isothermal oxidation tests were carried out at 800 °C for 5, 10, 25, 50, 100 and 150 h in static air. The oxidized samples were characterized by optical microscopy (OM), scanning electron microscopy (SEM), field emission microscopy (FESEM) with energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) analysis. Two groups of coatings with similar microstructures were obtained, and their influence on the formation of thermally oxidized growth layers was studied. From the isothermal oxidation tests, it was observed that the Ti48Al2Cr2Nb coatings have good resistance to oxidation in air at 800 °C in comparison with the Ti6Al4V substrate by obtaining layers of oxides up to 12 ¿m thick after 150 h of oxidation. The structure of the oxide layers is complex and comprises the growth of successive layers from the outer surface of the coating. The effect of the microstructure of the coating on the density of the oxide layer formed was evaluated.The authors would like to thank the Ministerio de Ciencia e Innovacion of the Spanish Government for their financial support through research project MAT2011-28492-C03 and the Generalitat Valenciana through grant ACOMP/2014/151.Zambrano Carrullo, JC.; Pereira Falcón, JC.; Amigó, V. (2019). Influence of process parameters and initial microstructure on the oxidation resistance of Ti48Al2Cr2Nb coating obtained by laser metal deposition. Surface and Coatings Technology. 358:114-124. https://doi.org/10.1016/j.surfcoat.2018.11.015S11412435

Population dynamics: seasonal variation of phytoplankton functional groups in brazilian reservoirs (Billings and Guarapiranga, São Paulo)

A comunidade fitoplanctônica pode funcionar como sensor das variações do ambiente aquático respondendo rapidamente as essas alterações. Em sistemas aquáticos continentais é comum a coexistência de espécies que possuem as mesmas necessidades ecológicas e apresentam as mesmas tolerâncias ambientais, tais grupos de espécies fitoplanctônicas são denominados grupos funcionais. O uso de grupos funcionais fitoplanctônicos para avaliar tais alterações tem se mostrado muito útil e eficaz. Assim, o objetivo do estudo foi avaliar a ocorrência de grupos funcionais fitoplanctônicos em dois reservatórios (Billings e Guarapiranga) que suprem de água milhões de pessoas na Região Metropolitana de São Paulo, Sudeste do Brasil. As amostras foram coletadas mensalmente na superfície da coluna d'água e foram analisadas as variáveis físicas, químicas e biológicas (análises qualitativa e quantitativa do fitoplâncton). Os maiores valores de biovolume (mm3.L-1) das espécies descritoras e grupos funcionais foram representados por Anabaena circinalis (H1), Microcystis aeruginosa (LM/M) e Mougeotia sp. (T) no Reservatório Guarapiranga e por Cylindrospermopsis raciborskii (SN), Microcystis aeruginosa e M. panniformis (LM/M), Planktothrix agardhii e P. cf. clathrata (S1) no Reservatório Billings. Os principais fatores ambientais que interferiram na dinâmica do fitoplâncton foram: temperatura da água, zona eufótica, turbidez, condutividade, pH, oxigênio dissolvido, nitrato e fósforo totalPhytoplankton may function as a "sensor" of changes in aquatic environment and responds rapidly to such changes. In freshwaters, coexistence of species that have similar ecological requirements and show the same environmental requirements frequently occurs; such species groups are named functional groups. The use of phytoplankton functional groups to evaluate these changes has proven to be very useful and effective. Thus, the aim of this study was to evaluate the occurrence of functional groups of phytoplankton in two reservoirs (Billings and Guarapiranga) that supply water to millions of people in São Paulo city Metropolitan Area, southeastern Brazil. Surface water samples were collected monthly and physical, chemical and biological (quantitative and qualitative analyses of the phytoplankton) were performed. The highest biovolume (mm3.L-1) of the descriptor species and functional groups were represented respectively by Anabaena circinalis Rabenh. (H1), Microcystis aeruginosa (Kützing) Kützing (LM/M) and Mougeotia sp. (T) in the Guarapiranga reservoir and Cylindrospermopsis raciborskii (Wolosz.) Seen. and Subba Raju (SN), Microcystis aeruginosa and M. panniformis Komárek et al. (LM/M), Planktothrix agardhii (Gom.) Anagn. and Komárek and P. cf. clathrata (Skuja) Anagn. and Komárek (S1) in the Billings reservoir. The environmental factors that most influenced the phytoplankton dynamics were water temperature, euphotic zone, turbidity, conductivity, pH, dissolved oxygen, nitrate and total phosphorou