Short Employment Spells in Italy, Germany and the UK: Testing the Port of Entry Hypothesis

This paper looks at short employment spells in three European countries: Great Britain, whose labour market is considered the most flexible in the EU; Italy, regarded as the least flexible; and Germany, tightly regulated, but characterised by a deservedly famous apprenticeship system. In particular, it aims to assess whether young people in short-lived jobs stand a better chance of finding a 'good job' compared to their older colleagues. The increasingly held belief that - in modern economies - a 'bad job' at the beginning of one's career is the 'port-of-entry' to stable employment and to upward mobility, makes this assessment particularly relevant; ie it matters greatly if short-duration jobs are entry ports into better employment or become long term-traps. The lack of accepted benchmarks makes it difficult to reach strong conclusions in regard to the 'efficiency' of labour markets, however, this study should help to highlight the effect of different labour market institutions on mobility and on the soundness of the 'port-of-entry' hypothesis.

Evolution of the mass, size, and star formation rate in high-redshift merging galaxies MIRAGE - A new sample of simulations with detailed stellar feedback

We aim at addressing the questions related to galaxy mass assembly through major and minor wet merging processes in the redshift range 1<z<2. A consequent fraction of Milky Way like galaxies are thought to have undergone an unstable clumpy phase at this early stage. Using the adaptive mesh refinement code RAMSES, with a recent physically-motivated implementation of stellar feedback, we build the Merging and Isolated high-Redshift Adaptive mesh refinement Galaxies (MIRAGE) sample. It is composed of 20 mergers and 3 isolated idealized disks simulations with global physical properties in accordance with the 1<z<2 mass complete sample MASSIV. The numerical hydrodynamical resolution reaches 7 parsecs in the smallest Eulerian cells. Our simulations include: star formation, metal line cooling, metallicity advection, and a recent implementation of stellar feedback which encompasses OB-type stars radiative pressure, photo-ionization heating, and supernovae. The initial conditions are set to match the z~2 observations, thanks to a new public code DICE. The numerical resolution allows us to follow the formation and evolution of giant clumps formed in-situ from Jeans instabilities triggered by high initial gas fraction. The star formation history of isolated disks shows stochastic star formation rate, which proceeds from the complex behavior of the giant clumps. Our minor and major gas-rich merger simulations do not trigger starbursts, suggesting a saturation of the star formation in a turbulent and clumpy interstellar medium fed by substantial accretion from the circum-galactic medium. Our simulations are close to the normal regime of the disk-like star formation on a Schmidt-Kennicutt diagram. The mass-size relation and its rate of evolution matches observations, suggesting that the inside-out growth mechanisms of the stellar disk do not necessarily require to be achieved through a cold accretion.Comment: 18 pages, 12 figures. Accepted in A&

Caracterização da Amazônia Legal e macrotendências do ambiente externo.

O Comitê Diretivo da Embrapa Estudos Estratégicos e Capacitação, respondendo à demanda dos Centros de Pesquisa sediados na Amazônia, da Diretoria Executiva e das Unidades Centrais, encomendou ao Núcleo de Estudos Estratégicos a elaboração de um estudo sobre a Embrapa na Amazônia. O objetivo central desse estudo é disponibilizar informações para a orientação futura das pesquisas agropecuárias na região, as quais poderão ser incorporadas, inclusive, na reformulação dos Planos Diretores das respectivas unidades. O Estudo Estratégico Embrapa na Amazônia, após a sua conclusão, será composto por uma série de documentos de apoio (DA), por um relatório final e por informações complementares que ficarão disponíveis na intranet da Embrapa. O presente texto é a versão preliminar, para discussão e posterior aperfeiçoamento, do Documento de Apoio 1 (DA-1), Caracterização da Amazônia Legal e macrotendências do ambiente externo. Outros documentos de apoio que serão disponibilizados nos meses vindouros versarão sobre Arranjos institucionais para a Embrapa na Amazônia (DA-2); Síntese das entrevistas e consultas eletrônicas com especialistas (DA-3); Macroestratégia para a pesquisa na Amazônia (DA-4) e Macroestratégia para a transferência de tecnologia na Amazônia (DA-5). Quanto aos objetivos desse primeiro documento de apoio tem-se: (i) caracterizar, segundo uma visão multifacetada, a Amazônia Legal; e (ii) apresentar e analisar grandes tendências para o setor agropecuário. Para a sua elaboração, foram consultados estudos sobre temas relavantes da região, extraindo deles componentes importantes para o possível reposicionamento futuro da pesquisa na região. Estes estudos serão posteriormente disponibilizados para consulta em biblioteca virtual. Complementarmente, nossa equipe avançou em análises inéditas, as quais serão igualmente disponibilizadas à comunidade científica oportunamente.bitstream/item/48150/1/GBMJ-EstudoAMZ-DA1-vISSN.pd

Amazônia: diferentes contextos, diferentes interpretações (síntese das entrevistas).

Como parte do estudo "Embrapa na Amazônia", foram realizadas diversas entrevistas com estudiosos de diferentes vínculos institucionais e experiências profissionais. Este documento tem o objetivo de sintetizar os excertos mais salientes das entrevistas, indicativos de temas relevantes e argumentos merecedores de maior atenção. Este relatório apresenta três partes principais. Na primeira delas, são sequenciados temas entendidos como majoritariamente convergentes, ou mais falados, indicando uma presumida concordância entre a maioria dos entrevistados, ainda que diversas nuances específicas possam ocorrer. Na segunda seção, são arroladas diversas manifestações selecionadas que parecem sugerir temas e focos de maior divergência, o principal deles, como seria esperado, a oposição entre "produção e ambiente". Para diversos analistas, esta é ainda uma polaridade, uma antinomia insuperável e um consenso que permita harmonizá-las ainda precisará percorrer caminho mais longo. Finalmente, este texto oferece uma terceira seção, final e mais sucinta, onde são arrolados alguns temas que parecem ser mais "neutros", se afastando de posicionamentos tão explícitos e apenas listando sugestões ou opiniões antes não apresentadas, nas duas seções anteriores.bitstream/item/48147/1/Entrevistas-DA4-V.ISSN.pd

Age Dating of a High-Redshift QSO B1422+231 at Z=3.62 and its Cosmological Implications

The observed Fe II(UV+optical)/Mg II lambda lambda 2796,2804 flux ratio from a gravitationally lensed quasar B1422+231 at z=3.62 is interpreted in terms of detailed modeling of photoionization and chemical enrichment in the broad-line region (BLR) of the host galaxy. The delayed iron enrichment by Type Ia supernovae is used as a cosmic clock. Our standard model, which matches the Fe II/Mg II ratio, requires the age of 1.5 Gyr for B1422+231 with a lower bound of 1.3 Gyr, which exceeds the expansion age of the Einstein-de Sitter Omega_0=1 universe at a redshift of 3.62 for any value of the Hubble constant in the currently accepted range, H_0=60-80 km,s^{-1},Mpc^{-1}. This problem of an age discrepancy at z=3.62 can be unraveled in a low-density Omega_0<0.2 universe, either with or without a cosmological constant, depending on the allowable redshift range of galaxy formation. However, whether the cosmological constant is a required option in modern cosmology awaits a thorough understanding of line transfer processes in the BLRs.Comment: 7 pages including 3 figures, to appear in ApJ Letter

Integral field spectroscopy with SINFONI of VVDS galaxies. II. The mass-metallicity relation at 1.2 < z < 1.6

This work aims to provide a first insight into the mass-metallicity (MZ) relation of star-forming galaxies at redshift z~1.4. To reach this goal, we present a first set of nine VVDS galaxies observed with the NIR integral-field spectrograph SINFONI on the VLT. Oxygen abundances are derived from empirical indicators based on the ratio between strong nebular emission-lines (Halpha, [NII]6584 and [SII]6717,6731). Stellar masses are deduced from SED fitting with Charlot & Bruzual (2007) population synthesis models, and star formation rates are derived from [OII]3727 and Halpha emission-line luminosities. We find a typical shift of 0.2-0.4 dex towards lower metallicities for the z~1.4 galaxies, compared to the MZ-relation in the local universe as derived from SDSS data. However, this small sample of eight galaxies does not show any clear correlation between stellar mass and metallicity, unlike other larger samples at different redshift (z~0, z~0.7, and z~2). Indeed, our galaxies lie just under the relation at z~2 and show a small trend for more massive galaxies to be more metallic (~0.1 logarithmic slope). There are two possible explanations to account for these observations. First, the most massive galaxies present higher specific star formation rates when compared to the global VVDS sample which could explain the particularly low metallicity of these galaxies as already shown in the SDSS sample. Second, inflow of metal-poor gas due to tidal interactions could also explain the low metallicity of these galaxies as two of these three galaxies show clear signatures of merging in their velocity fields. Finally, we find that the metallicity of 4 galaxies is lower by ~0.2 to 0.4 dex if we take into account the N/O abundance ratio in their metallicity estimate.Comment: 7 pages, 4 figures, accepted in A&A Comments: Comments: more accurate results with better stellar mass estimate

Photometric Observations of Star Formation Activity in Early Type Spirals

We observationally study the current star formation activities of early type spiral galaxies. We construct a complete sample of 15 early type spirals having far-infrared (FIR) to optical B band luminosity ratios, L(FIR)/L(B), larger than the average of the type, and make their CCD imaging of the R and H-alpha bands. The equivalent widths of H-alpha emission increase with increasing L(FIR)/L(B), indicating that L(FIR)/L(B) can be an indicator of star formation for such early type spirals with star formation activities higher than the average. For all of the observed early type spirals, the extended HII regions exist at the central regions with some asymmetric features. H-alpha emission is more concentrated to the galactic center than the R band light, and the degree of the concentration increases with the star formation activity. We also analyze the relation between the star formation activities and the existence of companion galaxies in the sample galaxies and other bright early type spirals. No correlation is found and this suggests that the interaction is not responsible for all of the star formation activities of early type spirals.Comment: LaTex, 23 pages (2 tables included), plus 9 Postscript figures & 1 table. To be published in AJ (November issue

Dimensão econômica de sistemas de integração lavoura-pecuária.

Os sistemas de integração lavoura-pecuária (ILP) têm sido propostos como solução tecnológica para atender critérios de sustentabilidade, mas tal assertiva tem-se baseado principalmente em indicadores agronômicos e ambientais. Neste trabalho, explorou-se a perspectiva econômica da ILP. Os benefícios econômicos potenciais desses sistemas podem refletir-se em economia de escopo (diminuição do custo, em razão da produção de múltiplos produtos) ou nos efeitos de redução de risco pela diversificação. Além disso, eles podem envolver menor variabilidade produtiva e maior produtividade. A mensuração acurada das interações entre os componentes lavoura e animal (pastagem) é etapa-chave a ser perseguida. A tomada de decisão em prol de sistemas diversificados vis?à?vis sistemas especializados deve ser feita de acordo com os preços relativos. A ILP compete com sistemas especializados de pecuária, mas não apresenta taxas de retorno competitivas em comparação a sistemas especializados com soja. A elevada demanda por capital da ILP, particularmente para a aquisição de animais em recria para a engorda, explica as menores taxas de retorno da ILP e é vista como uma das principais restrições para a ampla adoção de sistemas mistos. O desenho de mecanismos de financiamento inovadores será essencial para promover e acelerar a adoção em larga escala da tecnologia.Título em inglês: Economic dimension of integrated crop?livestock systems

Embrapa: its origins and changes.

Brazilian agriculture is a success story. The country that until the 1960s systematically received food donations from abroad. and up to the 1980s was still a large food importer, had its agriculture profoundly changed. The traditional agriculture that prevailed in Brazil until the 1970s was progressively transformed in the following decades into a modern and highly competitive agriculture based on science. Along with this structural transformation in the primary sector, the industry and service sectors directly linked to agriculture also became two of the world's biggest and most competitive. Furthermore, as food production increased at higher rates than food demand over time. food prices decreased.? These gains in consurner surplus took place due partially to lower income for Brazilian farmers.Na publicação: Eliseu Alves