The notion of the Cambrian pananimalia genome.

The toil by photosynthesizing cyanobacteria and blue-green algae of nearly three billion years appeared to have finally resulted in the sufficient accumulation of molecular oxygen. So, the stage was set for the emergence, at the ocean bottom, of diverse animals that were consumers of molecular oxygen. It now appears that this Cambrian explosion, during which nearly all the extant animal phyla have emerged, was of an astonishingly short duration, lasting only 6-10 million years. Inasmuch as only a 1% DNA base sequence change is expected in 10 million years under the standard spontaneous mutation rate, I propose that all those diverse animals of the early Cambrian period, some 550 million years ago, were endowed with nearly identical genomes, with differential usage of the same set of genes accounting for the extreme diversities of body forms. Some of the more pertinent genes that are thought to be included in the Cambrian pananimalia genome are as follows. (i) A gene for lysyloxidase that, in the presence of molecular oxygen, crosslinked collagen triple helices to produce ligaments and tendons, thus contributing to the stout bodies of the Cambrian animals. (ii) Genes for hemoglobin; these internal transporters of molecular oxygen are today seen sporadically in members of diverse animal phyla. (iii) The Pax-6 gene for eye formation; the eyes of a ribbon worm to a human are organized by this gene. In animals without eyes, the same gene organizes other sensory systems and organs. (iv) A series of Hox genes for the anterior-posterior (cranio-caudal) body plans: these genes are also present in all phyla of the kingdom Animalia.

No surviving evolved companions of the progenitor of SN 1006

Type Ia supernovae are thought to occur when a white dwarf made of carbon and oxygen accretes sufficient mass to trigger a thermonuclear explosion(1). The accretion could be slow, from an unevolved (main-sequence) or evolved (subgiant or giant) star(2,3) (the single-degenerate channel), or rapid, as the primary star breaks up a smaller orbiting white dwarf(3,4) (the double-degenerate channel). A companion star will survive the explosion only in the single-degenerate channel(5). Both channels might contribute to the production of type Ia supernovae(6,7), but the relative proportions of their contributions remain a fundamental puzzle in astronomy. Previous searches for remnant companions have revealed one possible case for SN 1572 (refs 8, 9), although that has been questioned(10). More recently, observations have restricted surviving companions to be small, main-sequence stars(11-13), ruling out giant companions but still allowing the single-degenerate channel. Here we report the results of a search for surviving companions of the progenitor of SN 1006 (ref. 14). None of the stars within 4 arc minutes of the apparent site of the explosion is associated with the supernova remnant, and we can firmly exclude all giant and subgiant stars from being companions of the progenitor. In combination with previous results, our findings indicate that fewer than 20 per cent of type Ia supernovae occur through the single-degenerate channel.

Efeito da adição de fibras de cana-de-açúcar pré-tratadas na produção de metano advinda da biodigestão anaeróbia de gorduras do leite

A digestão anaeróbia é uma alternativa para o tratamento de resíduos com altas concentrações de matéria orgânica. Por meio dos processos anaeróbios é possível a produção de biogás, fonte de energia renovável e ambientalmente amigável. Elevadas concentrações de lipídios, todavia, apesar de representarem elevado potencial metanogênico, interferem negativamente nos sistemas de tratamento, podendo inibir a atividade microbiana e, consequentemente, a produção de metano. O presente projeto avaliou o efeito da adição de bagaço de cana-de-açúcar no processo de biodigestão anaeróbia de elevadas concentrações de gorduras advindas de efluentes de laticínio. Para tanto foi utilizado bagaço de cana-de-açúcar in natura e pré-tratadas pelos seguintes métodos: organossolve, hidrotérmico, explosão à vapor e ácido diluído. O uso desse material lignocelulósico teve o objetivo de controlar a inibição causada pelos produtos da hidrólise dos lipídios por meio de sua adsorção e, consequentemente, diminuição das concentrações de tais compostos no meio. Outra hipótese era que o bagaço de cana-de-açúcar pudessem agir como co-substrato no processo de biodigestão anaeróbia. Inicialmente realizaram-se ensaios de biodegradabilidade anaeróbia com concentrações crescentes de gordura, que resultaram em relação entre substrato e microrganismo 0,06, 0,1, 0,2, 0,4 e 0,6 g DQO/gSTV. O ensaio com concentração em que foi verificada a inibição severa (0,4 gDQO/gSTV) do processo foi repetido com adição das fibras tratadas e não tratadas. Aos dados de produção acumulada de metano ajustou-se modelo de Gompertz, e parâmetros cinéticos foram inferidos. O bagaço de cana-de-açúcar mostrou potencial como adsorvente de gordura, pois as produções metanogênicas foram superiores à condição inibida sem adição desse material. A adição de fibras pré-tratadas por método organossolve resultou nas maiores produções de metano.

An Introduction to Conservation Easements in the United States: A Simple Concept and a Complicated Mosaic of Law

The idea of a conservation easement – restrictions on the development and use of land designed to protect the land’s conservation or historic values – can be relatively easily understood. More significant and more challenging is the complex body of state and federal laws that shapes the creation, funding, tax treatment, enforcement, modification, and termination of conservation easements. The explosion in the number of conservation easements over the past four decades has made them one of the most popular land protection mechanisms in the United States. The National Conservation Easement Database estimates that the total number of acres encumbered by conservation easements exceeds 40 million.Because conservation easements are both novel and ubiquitous, understanding how they actual work is essential for practicing lawyers, policymakers, land trust professionals, and students of conservation. This article provides a “quick tour” through some of the most important aspects of the developing mosaic of conservation easement law. It gives the reader a sense of the complex inter-jurisdictional dynamics that shape conservation transactions and disputes about conservation easements. Professors of property law, environmental law, tax law, and environmental studies who wish to cover conservation easements in the context of a more general course can use the article to provide their students with a broad but comprehensive overview of the relevant legal and policy issues.

Pulsar timing irregularities and the imprint of magnetic field evolution

Context. The rotational evolution of isolated neutron stars is dominated by the magnetic field anchored to the solid crust of the star. Assuming that the core field evolves on much longer timescales, the crustal field evolves mainly though Ohmic dissipation and the Hall drift, and it may be subject to relatively rapid changes with remarkable effects on the observed timing properties. Aims. We investigate whether changes of the magnetic field structure and strength during the star evolution may have observable consequences in the braking index n. This is the most sensitive quantity to reflect small variations of the timing properties that are caused by magnetic field rearrangements. Methods. We performed axisymmetric, long-term simulations of the magneto-thermal evolution of neutron stars with state-of-the-art microphysical inputs to calculate the evolution of the braking index. Relatively rapid magnetic field modifications can be expected only in the crust of neutron stars, where we focus our study. Results. We find that the effect of the magnetic field evolution on the braking index can be divided into three qualitatively different stages depending on the age and the internal temperature: a first stage that may be different for standard pulsars (with n ~ 3) or low field neutron stars that accreted fallback matter during the supernova explosion (systematically n < 3); in a second stage, the evolution is governed by almost pure Ohmic field decay, and a braking index n > 3 is expected; in the third stage, at late times, when the interior temperature has dropped to very low values, Hall oscillatory modes in the neutron star crust result in braking indices of a high absolute value and both positive and negative signs. Conclusions. Current magneto-thermal evolution models predict a large contribution to the timing noise and, in particular, to the braking index, from temporal variations of the magnetic field. Models with strong (≳ 1014 G) multipolar or toroidal components, even with a weak (~1012 G) dipolar field are consistent with the observed trend of the timing properties.

Culture Industries in a Postindustrial Age: Entertainment, Leisure, Creativity, Design

This article reviews the evolution of the concept of culture industries, when neither industry nor culture themselves are today what they were at the time when the term was coined. It attempts to explain the dilution of the term into more nebulous terms (“leisure industries,” “entertainment industries” or “creative industries”) and suggests new challenges for the research on culture industries. What is at stake is no longer an application of a Fordist production to culture, a one-directional mass communication and a mediation by experts, but rather: (1) a cultural experience which is no longer clearly separated from other activities (leisure in general, consumption and even work); (2) the communicative explosion of all industrial production in a media environment, where industrialized symbolic products are mixed with culturalized industrial products; and (3) the empowerment of the recipient, which on one hand ignores the traditional experts and on the other leads to post-productive (recreational and even creative) cultural practices.

On the formation and evolution of the first Be star in a black hole binary MWC 656

We find that the formation of MWC 656 (the first Be binary containing a black hole) involves a common envelope phase and a supernova explosion. This result supports the idea that a rapidly rotating Be star can emerge out of a common envelope phase, which is very intriguing because this evolutionary stage is thought to be too fast to lead to significant accretion and spin up of the B star. We predict ∼10–100 of B-BH binaries to currently reside in the Galactic disc, among which around 1/3 contain a Be star, but there is only a small chance to observe a system with parameters resembling MWC 656. If MWC 656 is representative of intrinsic Galactic Be-BH binary population, it may indicate that standard evolutionary theory needs to be revised. This would pose another evolutionary problem in understanding black hole (BH) binaries, with BH X-ray novae formation issue being the prime example. Future evolution of MWC 656 with an ∼5 M⊙ BH and with an ∼13 M⊙ main-sequence companion on an ∼60 d orbit may lead to the formation of a coalescing BH–NS (neutron star) system. The estimated Advanced LIGO/Virgo detection rate of such systems is up to ∼0.2 yr−1. This empirical estimate is a lower limit as it is obtained with only one particular evolutionary scenario, the MWC 656 binary. This is only a third such estimate available (after Cyg X-1 and Cyg X-3), and it lends additional support to the existence of so far undetected BH–NS binaries.

Desenvolvimento sustentável: a educação e o ambiente

O desenvolvimento sustentável é um tema atual que tem despertado preocupações e crescente interesse social. A acentuada explosão demográfica nos anos 50 pôs em causa a relação entre a sociedade e o ambiente. Este estudo tem como objetivo sensibilizar a comunidade educativa para os problemas ambientais e contribuir para a formação de cidadãos ambientalmente cultos e globalmente intervenientes. Utilizou-se como metodologia a pesquisa bibliográfica através de livros, revistas e fontes eletrónicas. O aumento da população mundial e a intervenção antrópica, são as principais causas dos problemas ambientais. Em Portugal, o desenvolvimento sustentável e a educação ambiental são temáticas abordadas nos vários anos de escolaridade, numa perspetiva horizontal e vertical.

Doença de Hirschsprung : abordagem sumária de um caso clínico

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Malta Transformed by Multi-level Governance: More Than Just an Outcome of Europeanisation. Occasional Paper 03/2014

Malta has been transformed in many ways with and by EU Membership. This paper goes beyond the more obvious impacts of ‘Europeanisation’ and instead reviews the implications of an explosion of multi-level governance on doing politics in Malta. While for most of its recent political history, there has been a clawing back of power by the central government – as when the Gozo Civic Council (1960-1973), an early foray into regional government, was “unceremoniously dissolved” in 1973 – this trend was reversed with the setting up of local councils as from 1994, an advisory Malta Council for Economic and Social Development (MCESD) in 2001, and then EU membership in 2004. These events have created a profligacy of decision-making tiers and multiplied the tensions that exist between different levels of governance in this small archipelago state. Malta has never experienced such pluralism before. In fact, since 1966, only two political parties have been represented in the national legislature and, therefore, there has been no division of powers between the executive and the national parliament. This paper reviews the implications of these developments on two hot political issues in 2014: the International Investor Programme (IIP) proposed by the Labour Government in its 2014 Budget; and the location of a Liquid Natural Gas (LNG)-storage vessel inside Marsaxlokk harbour.

War Crimes and Shifting Borders in the Middle East. CEPS Essay No. 14, 11 September 2014

The summer of 2014 saw an explosion of violence in the Middle East: Israel delivered a sledgehammer blow against Gaza, Lebanon was again the scene of terrorist onslaught, and the relentless war in Syria pushed the numbers of casualties and displaced people to record highs. In terms of geopolitical change, however, the advance of the ‘Islamic State’ and the emergence of a de facto independent Iraqi Kurdistan are the most important recent developments in the region. Common to all these conflicts are the levels of barbarity involved in this struggle for a place in the region’s security order.

Alteration of natural ³⁷Ar activity concentration in the subsurface by gas transport and water infiltration

High ³⁷Ar activity concentration in soil gas is proposed as a key evidence for the detection of underground nuclear explosion by the Comprehensive Nuclear Test-Ban Treaty. However, such a detection is challenged by the natural background of ³⁷Ar in the subsurface, mainly due to Ca activation by cosmic rays. A better understanding and improved capability to predict ³⁷Ar activity concentration in the subsurface and its spatial and temporal variability is thus required. A numerical model integrating ³⁷Ar production and transport in the subsurface is developed, including variable soil water content and water infiltration at the surface. A parameterized equation for ³⁷Ar production in the first 15 m below the surface is studied, taking into account the major production reactions and the moderation effect of soil water content. Using sensitivity analysis and uncertainty quantification, a realistic and comprehensive probability distribution of natural ³⁷Ar activity concentrations in soil gas is proposed, including the effects of water infiltration. Site location and soil composition are identified as the parameters allowing for a most effective reduction of the possible range of ³⁷Ar activity concentrations. The influence of soil water content on ³⁷Ar production is shown to be negligible to first order, while ³⁷Ar activity concentration in soil gas and its temporal variability appear to be strongly influenced by transient water infiltration events. These results will be used as a basis for practical CTBTO concepts of operation during an OSI.

Morphomechanical Innovation Drives Explosive Seed Dispersal

How mechanical and biological processes are coordinated across cells, tissues, and organs to produce complex traits is a key question in biology. Cardamine hirsuta, a relative of Arabidopsis thaliana, uses an explosive mechanism to disperse its seeds. We show that this trait evolved through morphomechanical innovations at different spatial scales. At the organ scale, tension within the fruit wall generates the elastic energy required for explosion. This tension is produced by differential contraction of fruit wall tissues through an active mechanism involving turgor pressure, cell geometry, and wall properties of the epidermis. Explosive release of this tension is controlled at the cellular scale by asymmetric lignin deposition within endocarp b cells-a striking pattern that is strictly associated with explosive pod shatter across the Brassicaceae plant family. By bridging these different scales, we present an integrated mechanism for explosive seed dispersal that links evolutionary novelty with complex trait innovation.

Halogen deposition in polar snow and ice

The atmospheric chemistry of iodine and bromine in polar regions is of interest due to the key role of halogens in many atmospheric processes, particularly tropospheric ozone destruction. Bromine is emitted from the open ocean but is enriched above first-year sea ice during springtime bromine explosion events, whereas iodine is emitted from biological communities hosted by sea ice. It has been previously demonstrated that bromine and iodine are present in Antarctic ice over glacial-interglacial cycles. Here we investigate seasonal variability of bromine and iodine in polar snow and ice, to evaluate their emission, transport and deposition in Antarctica and the Arctic and better understand potential links to sea ice. We find that bromine enrichment (relative to sea salt content) and iodine concentrations in polar ice do vary seasonally in Arctic snow and Antarctic ice and we relate such variability to satellite-based observations of tropospheric halogen concentrations. Peaks of bromine enrichment in Arctic snow and Antarctic ice occur in spring and summer, when sunlight is present. Iodine concentrations are largest in winter Antarctic ice strata, contrary to contemporary observations of summer maxima in iodine emissions.