University of Lisbon

About: University of Lisbon is a education organization based out in Lisbon, Lisboa, Portugal. It is known for research contribution in the topics: Population & Context (language use). The organization has 19122 authors who have published 48503 publications receiving 1102623 citations. The organization is also known as: Universidade de Lisboa & Lisbon University.

What is bioturbation? The need for a precise definition for fauna in aquatic sciences

Abstract: The term 'bioturbation' is frequently used to describe how living organisms affect the substratum in which they live. A closer look at the aquatic science literature reveals, however, an inconsistent usage of the term with increasing perplexity in recent years. Faunal disturbance has often been referred to as particle reworking, while water movement (if considered) is re ferred to as bioirrigation in many cases. For consistency, we therefore propose that, for contemporary aquatic scientific disciplines, faunal bioturbation in aquatic environments includes all transport processes carried out by animals that directly or indirectly affect sediment matrices. These pro- cesses include both particle reworking and burrow ventilation. With this definition, bioturbation acts as an 'umbrella' term that covers all transport processes and their physical effects on the sub- stratum. Particle reworking occurs through burrow construction and maintenance, as well as ingestion and defecation, and causes biomixing of the substratum. Organic matter and microor- ganisms are thus displaced vertically and laterally within the sediment matrix. Particle reworking animals can be categorized as biodiffusors, upward conveyors, downward conveyors and regen- erators depending on their behaviour, life style and feeding type. Burrow ventilation occurs when animals flush their open- or blind-ended burrows with overlying water for respiratory and feeding purposes, and it causes advective or diffusive bioirrigation ex change of solutes between the sedi- ment pore water and the overlying water body. Many bioturbating species perform reworking and ventilation simultaneously. We also propose that the effects of bioturbation on other organisms and associated processes (e.g. microbial driven biogeochemical transformations) are considered within the conceptual framework of ecosystem engineering.

Assemblathon 2: evaluating de novo methods of genome assembly in three vertebrate species

Abstract: Background: The process of generating raw genome sequence data continues to become cheaper, faster, and more accurate. However, assembly of such data into high-quality, finished genome sequences remains challenging. Many genome assembly tools are available, but they differ greatly in terms of their performance (speed, scalability, hardware requirements, acceptance of newer read technologies) and in their final output (composition of assembled sequence). More importantly, it remains largely unclear how to best assess the quality of assembled genome sequences. The Assemblathon competitions are intended to assess current state-of-the-art methods in genome assembly. Results: In Assemblathon 2, we provided a variety of sequence data to be assembled for three vertebrate species (a bird, a fish, and snake). This resulted in a total of 43 submitted assemblies from 21 participating teams. We evaluated these assemblies using a combination of optical map data, Fosmid sequences, and several statistical methods. From over 100 different metrics, we chose ten key measures by which to assess the overall quality of the assemblies. (Continued on next page)

The North Atlantic Oscillation influence on Europe: climate impacts and associated physical mechanisms

Abstract: A multivariable analysis of the influence of the North Atlantic Oscillation (NAO) on the climate of the North Atlantic and European sectors is presented using the 40 yr (1958-1997) consis- tent data set from NCEP. Using high and low NAO index composites, anomaly fields of climate vari- ables are then interpreted based on physical mechanisms associated with the anomalous mean flow (characterised by the surface wind field) and the anomalous eddy activity (characterised by the sur- face vorticity and the 500 hPa storm track fields). It is shown that NAO-related temperature patterns are mainly controlled by the advection of heat by the anomalous mean flow. However, large asym- metries between minimum and maximum temperatures, and more significantly, between positive and negative phases of NAO imply the importance of a different mechanism, namely, the modulation of short wave and long wave radiation by cloud cover variations associated with the NAO. Further- more, NAO influence on 2 different precipitation-related variables—precipitation rate and precip- itable water—displays different patterns. Precipitable water is shown to be strongly related to the corresponding anomaly fields of temperature while precipitation rate appears to be controlled by the surface vorticity field and associated strength of the tropospheric synoptic activity.

European Society of Cardiology: Cardiovascular Disease Statistics 2017

Abstract: Background: The European Society of Cardiology (ESC) Atlas has been compiled by the European Heart Agency to document cardiovascular disease (CVD) statistics of the 56 ESC member countries. A major aim of this 2017 data presentation has been to compare high income and middle income ESC member countries, in order to identify inequalities in disease burden, outcomes and service provision. Methods: The Atlas utilizes a variety of data sources, including the World Health Organization, the Institute for Health Metrics and Evaluation, and the World Bank to document risk factors, prevalence and mortality of cardiovascular disease and national economic indicators. It also includes novel ESC sponsored survey data of health infrastructure and cardiovascular service provision provided by the national societies of the ESC member countries. Data presentation is descriptive with no attempt to attach statistical significance to differences observed in stratified analyses. Results: Important differences were identified between the high income and middle income member countries of the ESC with regard to CVD risk factors, disease incidence and mortality. For both women and men, the age-standardised prevalence of hypertension was lower in high income countries (18.3% and 27.3%) compared with middle income countries (23.5% and 30.3%). Smoking prevalence in men (not women) was also lower (26% vs 41.3%), and together these inequalities are likely to have contributed to the higher CVD mortality in middle income countries. Declines in CVD mortality have seen cancer becoming a more common cause of death in a number of high income member countries, but in middle income countries declines in CVD mortality have been less consistent where CVD remains the leading cause of death. Inequalities in CVD mortality are emphasised by the smaller contribution they make to potential years of life lost in high income compared with middle income countries both for women (13% vs. 23%) and men (20% vs. 27%). The downward mortality trends for CVD may, however, be threatened by the emerging obesity epidemic that is seeing rates of diabetes increasing across all ESC member countries. Survey data from the National Cardiac Societies (n=41) showed that rates of cardiac catheterization and coronary artery bypass surgery, as well as the number of specialist centres required to deliver them, were greatest in the high income member countries of the ESC. The Atlas confirmed that these ESC member countries, where the facilities for the contemporary treatment of coronary disease were best developed, were often those in which declines in coronary mortality have been most pronounced. Economic resources were not the only driver for delivery of equitable cardiovascular healthcare, as some middle income ESC member countries reported rates for interventional procedures and device implantations that matched or exceeded the rates in wealthier member countries. Conclusion: In documenting national CVD statistics, the Atlas provides valuable insights into the inequalities in risk factors, healthcare delivery and outcomes of CVD across ESC member countries. The availability of these data will underpin the ESC’s ambitious mission “to reduce the burden of cardiovascular disease” not only in its member countries, but also in nation states around the world.

A Gaia DR2 view of the open cluster population in the Milky Way

Abstract: Context. Open clusters are convenient probes of the structure and history of the Galactic disk. They are also fundamental to stellar evolution studies. The second Gaia data release contains precise astrometry at the submilliarcsecond level and homogeneous photometry at the mmag level, that can be used to characterise a large number of clusters over the entire sky.Aims. In this study we aim to establish a list of members and derive mean parameters, in particular distances, for as many clusters as possible, making use of Gaia data alone.Methods. We compiled a list of thousands of known or putative clusters from the literature. We then applied an unsupervised membership assignment code, UPMASK, to the Gaia DR2 data contained within the fields of those clusters.Results. We obtained a list of members and cluster parameters for 1229 clusters. As expected, the youngest clusters are seen to be tightly distributed near the Galactic plane and to trace the spiral arms of the Milky Way, while older objects are more uniformly distributed, deviate further from the plane, and tend to be located at larger Galactocentric distances. Thanks to the quality of Gaia DR2 astrometry, the fully homogeneous parameters derived in this study are the most precise to date. Furthermore, we report on the serendipitous discovery of 60 new open clusters in the fields analysed during this study.