Trans-Pacific migrations of the loggerhead turtle (Caretta caretta) demonstrated with mitochondrial DNA markers.

Juvenile loggerhead turtles (Caretta caretta) have recently been documented in the vicinity of Baja California and thousands of these animals have been captured in oceanic fisheries of the North Pacific. The presence of loggerhead turtles in the central and eastern North Pacific is a prominent enigma in marine turtle distribution because the nearest documented nesting concentrations for this species are in Australia and Japan, over 10,000 km from Baja California. To determine the origin of the Baja California feeding aggregate and North Pacific fishery mortalities, samples from nesting areas and pelagic feeding aggregates were compared with genetic markers derived from mtDNA control region sequences. Overall, 57 of 60 pelagic samples (95%) match haplotypes seen only in Japanese nesting areas, implicating Japan as the primary source of turtles in the North Pacific Current and around Baja California. Australian nesting colonies may contribute the remaining 5% of these pelagic feeding aggregates. Juvenile loggerhead turtles apparently traverse the entire Pacific Ocean, approximately one-third of the planet, in the course of developmental migrations, but mortality in high-seas fisheries raises concern over the future of this migratory population.

Desigualdade social entre as crianças menores de 5 anos em diferentes regiões mundiais

Introdução: A Organização Mundial da Saúde indica que a prevalência do déficit de altura tem diminuído no planeta nas últimas décadas, pouco se sabe ainda sobre os fatores associados a este declínio ou sua associação com a desigualdade social. Objetivo: Descrever a evolução do déficit de altura e da desigualdade socioeconômica em diferentes regiões do mundo. Métodos: A pesquisa foi baseada em dados secundários provenientes do programa Demografic Health Surveys DHS de 6 sub-regiões do mundo representando 24 países em um total de 48 pesquisas na década de 90 e na primeira década do século 21 com 377.151 crianças menores de 5 anos. Foi considerada como variável de interesse o Déficit de altura para idade considerado como a ocorrência deste índice inferior a -2 escore Z da distribuição de referência WHO-2006. Foram imputados através de modelo de regressão os valores faltantes das variáveis água para beber, esgoto sanitário e escolaridade materna. Foi estimado o Índice de Concentração para as variáveis déficit de altura, educação materna deficiente, água para beber insegura, esgoto domiciliar deficiente e ocorrência de doenças, tendo como variável de ranqueamento o Índice de Riqueza. Dados do poder de paridade de compra fornecidos pelo Banco Mundial foram utilizados para verificar as diferenças na evolução da desnutrição. Resultados: Nessa análise acerca da evolução da desigualdade socioeconômica do déficit de altura para idade em países em desenvolvimento constatou-se que: a) a prevalência do déficit de altura para idade decresceu em 87 por cento dos países; b) apenas 8 países (33 por cento ) aumentaram a diferença entre prevalência do déficit de altura nos quintos extremos c) quatorze países (58 por cento ) evoluíram com diminuição do déficit de altura e aumento do índice de concentração; d) Dois países que diminuíram a o déficit de altura e a desigualdade tinham os menores valores de escolaridade materna deficiente; e) 13 países (93 por cento ) daqueles que diminuíram déficit mas aumentaram a desigualdade possuíam indicadores de vulnerabilidade infantil deficientes. Conclusões: Os países em desenvolvimento apresentam redução no déficit de altura em crianças menores de 5 anos. A diminuição da desigualdade na riqueza e na escolaridade materna deficiente explicaram maior parte da melhoria da desigualdade do déficit de altura para idade.

DUst around NEarby Stars. The survey observational results

Context. Debris discs are a consequence of the planet formation process and constitute the fingerprints of planetesimal systems. Their solar system counterparts are the asteroid and Edgeworth-Kuiper belts. Aims. The DUNES survey aims at detecting extra-solar analogues to the Edgeworth-Kuiper belt around solar-type stars, putting in this way the solar system into context. The survey allows us to address some questions related to the prevalence and properties of planetesimal systems. Methods. We used Herschel/PACS to observe a sample of nearby FGK stars. Data at 100 and 160 μm were obtained, complemented in some cases with observations at 70 μm, and at 250, 350 and 500 μm using SPIRE. The observing strategy was to integrate as deep as possible at 100 μm to detect the stellar photosphere. Results. Debris discs have been detected at a fractional luminosity level down to several times that of the Edgeworth-Kuiper belt. The incidence rate of discs around the DUNES stars is increased from a rate of ~12.1% ± 5% before Herschel to ~20.2% ± 2%. A significant fraction (~52%) of the discs are resolved, which represents an enormous step ahead from the previously known resolved discs. Some stars are associated with faint far-IR excesses attributed to a new class of cold discs. Although it cannot be excluded that these excesses are produced by coincidental alignment of background galaxies, statistical arguments suggest that at least some of them are true debris discs. Some discs display peculiar SEDs with spectral indexes in the 70–160 μm range steeper than the Rayleigh-Jeans one. An analysis of the debris disc parameters suggests that a decrease might exist of the mean black body radius from the F-type to the K-type stars. In addition, a weak trend is suggested for a correlation of disc sizes and an anticorrelation of disc temperatures with the stellar age.

Competitividade da cadeia produtiva do Arapaima gigas, o pirarucu da Amazônia brasileira

Com um quinto da água doce do planeta, o sistema fluvial da Amazônia apresenta um enorme potencial para piscicultura. De acordo com a FAO, em função das suas condições geográficas, o Brasil é um dos poucos países que tem condições de atender à crescente demanda mundial, podendo tornar-se um dos maiores produtores de peixes do mundo. A observação desse potencial amazônico motivou o desenvolvimento desta pesquisa que se debruça sobre a questão da competitividade da cadeia produtiva de Arapaima gigas, o pirarucu da Amazônia brasileira. As pesquisas de campo levaram ao mapeamento de duas cadeias: a cadeia extrativista e a piscicultura. A abordagem sistêmica permitiu a verificação das características dos atores e as bases sob as quais as transações se estabelecem. À luz da teoria das restrições foram identificados os gargalos que impedem a competitividade do sistema, inclusive alertando para os recursos com restrição de capacidade. Comprovou-se que a falta de uma cadeia produtiva devidamente organizada pode provocar graves prejuízos a determinados elos, enquanto outros membros aproveitam-se de ações oportunistas para ampliar suas margens de lucro. Da mesma forma, a ausência de uma cadeia produtiva completa impede a fixação do valor gerado na região de origem das matérias-primas. No entanto, também foi possível comprovar que há possibilidade de desenvolver o extrativismo atribuindo valor econômico aos recursos naturais e gerando renda para a comunidade local. Além de apresentar o panorama do setor na região delimitada, este estudo culminou em reflexões capazes de orientar políticas públicas para o desenvolvimento de cadeias produtivas completas na região da Amazônia brasileira.

EChO. Exoplanet characterisation observatory

A dedicated mission to investigate exoplanetary atmospheres represents a major milestone in our quest to understand our place in the universe by placing our Solar System in context and by addressing the suitability of planets for the presence of life. EChO—the Exoplanet Characterisation Observatory—is a mission concept specifically geared for this purpose. EChO will provide simultaneous, multi-wavelength spectroscopic observations on a stable platform that will allow very long exposures. The use of passive cooling, few moving parts and well established technology gives a low-risk and potentially long-lived mission. EChO will build on observations by Hubble, Spitzer and ground-based telescopes, which discovered the first molecules and atoms in exoplanetary atmospheres. However, EChO’s configuration and specifications are designed to study a number of systems in a consistent manner that will eliminate the ambiguities affecting prior observations. EChO will simultaneously observe a broad enough spectral region—from the visible to the mid-infrared—to constrain from one single spectrum the temperature structure of the atmosphere, the abundances of the major carbon and oxygen bearing species, the expected photochemically-produced species and magnetospheric signatures. The spectral range and resolution are tailored to separate bands belonging to up to 30 molecules and retrieve the composition and temperature structure of planetary atmospheres. The target list for EChO includes planets ranging from Jupiter-sized with equilibrium temperatures T_ eq up to 2,000 K, to those of a few Earth masses, with T _eq \u223c 300 K. The list will include planets with no Solar System analog, such as the recently discovered planets GJ1214b, whose density lies between that of terrestrial and gaseous planets, or the rocky-iron planet 55 Cnc e, with day-side temperature close to 3,000 K. As the number of detected exoplanets is growing rapidly each year, and the mass and radius of those detected steadily decreases, the target list will be constantly adjusted to include the most interesting systems. We have baselined a dispersive spectrograph design covering continuously the 0.4–16 μm spectral range in 6 channels (1 in the visible, 5 in the InfraRed), which allows the spectral resolution to be adapted from several tens to several hundreds, depending on the target brightness. The instrument will be mounted behind a 1.5 m class telescope, passively cooled to 50 K, with the instrument structure and optics passively cooled to \u223c45 K. EChO will be placed in a grand halo orbit around L2. This orbit, in combination with an optimised thermal shield design, provides a highly stable thermal environment and a high degree of visibility of the sky to observe repeatedly several tens of targets over the year. Both the baseline and alternative designs have been evaluated and no critical items with Technology Readiness Level (TRL) less than 4–5 have been identified. We have also undertaken a first-order cost and development plan analysis and find that EChO is easily compatible with the ESA M-class mission framework.

Chromospheric activity and rotation of FGK stars in the solar vicinity. An estimation of the radial velocity jitter

Context. Chromospheric activity produces both photometric and spectroscopic variations that can be mistaken as planets. Large spots crossing the stellar disc can produce planet-like periodic variations in the light curve of a star. These spots clearly affect the spectral line profiles, and their perturbations alter the line centroids creating a radial velocity jitter that might “contaminate” the variations induced by a planet. Precise chromospheric activity measurements are needed to estimate the activity-induced noise that should be expected for a given star. Aims. We obtain precise chromospheric activity measurements and projected rotational velocities for nearby (d ≤ 25 pc) cool (spectral types F to K) stars, to estimate their expected activity-related jitter. As a complementary objective, we attempt to obtain relationships between fluxes in different activity indicator lines, that permit a transformation of traditional activity indicators, i.e., Ca II H & K lines, to others that hold noteworthy advantages. Methods. We used high resolution (~50 000) echelle optical spectra. Standard data reduction was performed using the IRAF ECHELLE package. To determine the chromospheric emission of the stars in the sample, we used the spectral subtraction technique. We measured the equivalent widths of the chromospheric emission lines in the subtracted spectrum and transformed them into fluxes by applying empirical equivalent width and flux relationships. Rotational velocities were determined using the cross-correlation technique. To infer activity-related radial velocity (RV) jitter, we used empirical relationships between this jitter and the R’_HK index. Results. We measured chromospheric activity, as given by different indicators throughout the optical spectra, and projected rotational velocities for 371 nearby cool stars. We have built empirical relationships among the most important chromospheric emission lines. Finally, we used the measured chromospheric activity to estimate the expected RV jitter for the active stars in the sample.

Percepções sociais sobre o futuro da humanidade no planeta: um estudo na cidade de Piracicaba, SP

A pesquisa sobre as percepções de residentes da região de Piracicaba em relação às questões ambientais e ao futuro da humanidade no planeta foi desenvolvida com base em um questionário semi-estruturado. As questões buscaram levantar dados autoavaliativos sobre perfil, comportamentos, estado de humor, qualidade de vida, condição econômica e hábitos de consumo, práticas para destinação de resíduos, iniciativas de exercício de cidadania em prol da sustentabilidade socioambiental, para enfim, indagar sobre percepções de futuro e avaliações sobre o contexto socioambiental dos participantes da pesquisa. A aplicação dos questionários foi feita de forma aleatória estratificada nos bairros das cinco regiões da cidade de Piracicaba: Norte, Sul, Leste, Oeste e Centro. Por meio dessas aplicações, foram obtidos 655 questionários, que foram sistematizados, tabulados e analisados estatisticamente, utilizando-se gráficos de frequência, o Teste de Kruskal Wallis, os Testes de Correlação de Spearman e Kendall, o Teste de Qui-Quadrado e o Teste Exato de Fisher. Foram também criadas nuvens de palavras, desenvolvidas no software online \"Wordle\" (FEINBERG, 2014). Os resultados obtidos com essa pesquisa e as análises desenvolvidas indicam que 227 pessoas, isto é, aproximadamente 35% dos respondentes, possui uma percepção pessimista sobre o futuro da humanidade no planeta. Porém, 493 pessoas, o equivalente a aproximadamente 75% do total de respondentes, considerou que, dentre as alternativas apresentadas no questionário (Desenvolvimento de tecnologias; Controle de natalidade; Educação e mudanças culturais; Cobrança de impostos com base nos impactos ambientais; Intervenção do Estado), a educação e mudanças culturais são fundamentais no processo de transformação social e de superação das problemáticas ambientais. Observou-se também que a crise hídrica vivenciada na época em que os questionários foram aplicados também influenciou na percepção social dos respondentes, uma vez que a palavra \"água\" foi citada 380 vezes. Por meio do trabalho, foi também possível analisar o comportamento ambiental dos pesquisados, notando-se que ainda há a necessidade de promoção de atividades educacionais e comunicacionais que possam estimular a adoção de hábitos e comportamentos mais comprometidos com ideias de sustentabilidade e que levem a mudanças mais efetivas nos padrões de relacionamento entre sociedade e meio ambiente.

El occidente musulmán en los mapas del Mediterráneo de la «escuela de al-Baljî»

Las costas enfrentadas de al-Andalus y del Mágreb como una reinterpretación de un Mediterráneo en el que se recogen únicamente las costas musulmanas del mismo, especialmente en la cartografía de la conocida como "escuela de al-Baljî", con un eco de esta concepción, reflejado posteriormente en la descripción como "costas enfrentadas" de Al-Masâlik wa-l-mamâlik escrito por el andalusí al-Bakrî (s. XI).

Ni bueno, ni bonito, ni barato. El problema de la simplificación de la naturaleza

Modern society has lost its natural connection with the environment. Present agriculture methods and city planning around the world support this fact. Humanity has always simplified nature in order to control it but, far from this, we have contributed to enhance current environmental issues as air and water pollution, soil fertility loss, species extinction and climate change. Therefore, it may be reasonable to change our point of view of nature. By assuming that we are an inseparable part of nature and vice versa, we may achieve a true conservation of the richness of our planet. We must synthesise nature because every living being is a part of a bigger whole. We need to live the complexity of life. Nowadays, we have reached a turning point after which we must decide either changing our ways or sacrificing our future. Hopefully, a slight impulse is sometimes enough to change the course of History.

Pulsar science with the SKA

The unprecedented sensitivity and large field of view of SKA will be of paramount importance for pulsar science, and for many related research fields. In particular, beside the obvious discovery of many more pulsars (even those with very low luminosity), and the extremely accurate timing analysis of the current pulsar population, SKA will allow to use pulsars to measure or put strong constraints on gravitational waves, Galactic magnetism, planet masses, general relativity and nuclear physics.

Earth’s Rotation: A Challenging Problem in Mathematics and Physics

A suitable knowledge of the orientation and motion of the Earth in space is a common need in various fields. That knowledge has been ever necessary to carry out astronomical observations, but with the advent of the space age, it became essential for making observations of satellites and predicting and determining their orbits, and for observing the Earth from space as well. Given the relevant role it plays in Space Geodesy, Earth rotation is considered as one of the three pillars of Geodesy, the other two being geometry and gravity. Besides, research on Earth rotation has fostered advances in many fields, such as Mathematics, Astronomy and Geophysics, for centuries. One remarkable feature of the problem is in the extreme requirements of accuracy that must be fulfilled in the near future, about a millimetre on the tangent plane to the planet surface, roughly speaking. That challenges all of the theories that have been devised and used to-date; the paper makes a short review of some of the most relevant methods, which can be envisaged as milestones in Earth rotation research, emphasizing the Hamiltonian approach developed by the authors. Some contemporary problems are presented, as well as the main lines of future research prospected by the International Astronomical Union/International Association of Geodesy Joint Working Group on Theory of Earth Rotation, created in 2013.

Tackling the Big Challenges of the Future: The Role of Chemistry

The end of 2015 was the deadline that 189 countries gave themselves to achieve the United Nations Millennium Development Goals (MDGs), a list of eight goals that were agreed upon and approved by the UN after the Millennium Summit in year 2000. Despite some legitimate criticism, the MDGs were revealed as an important tool towards building a more equitable and sustainable world. Yet our planet still faces many challenges. In September 2015, the UN approved a new set of 17 goals, the Sustainable Development Goals (SDGs), aiming to develop and implement strategies to create “The Future We Want”; strategies that 192 countries agreed upon to work together towards a more sustainable planet.

Student mathematical proofs by Edward Stephen (?) Wigglesworth, 1788

Sheet with two handwritten mathematical proofs signed "Wigglesworth, 1788," likely referring Harvard student Edward Stephen Wigglesworth. The first proof, titled "Problem 1st," examines a prompt beginning, "Given the distance between the Centers of the Sun and Planet, and their quantities of matter; to find a place where a body will be attracted to neither of them." The second proof, titled "Problem 2d," begins "A & B having returned from a journey, had riden [sic] so far that if the square of the number of miles..." and asks "how many miles did each of them travel?"

Como seria a Terra sem a lua?

A vida que existe na Terra resulta de um conjunto de circunstâncias muito particulares e raras nas quais se inclui a presença da Lua. A Lua é o satélite natural da Terra e os dois planetas influenciam-se mutuamente. Apesar de ser um pequeno planeta a Lua é responsável por vários fenómenos terrestres como as marés que afetam a velocidade de rotação da Terra. O seu afastamento, apesar de lento é constante e provocará alterações nas condições do planeta que permitem sustentar a vida e afectará algumas espécies em particular.

Análise do regime de produção distribuída fotovoltaica para autoconsumo

Tese de mestrado integrado em Engenharia da Energia e do Ambiente, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2016