Detrital zircon from a late Paleozoic accretionary complex of SW Iberia (Variscan Belt): History of crustal growth and recycling at the Rheic convergent margin

In this study we present new U-Pb ages of detrital zircons from greywackes and quartzites of the Pulo do Lobo Anticline (PLA) that have been interpreted to represent a Late Paleozoic accretionary complex in SW Iberia. The PLA separates the Ossa Morena Zone, which has a North- Gondwana affinity throughout Late Ediacaran and Early Paleozoic times, from the South Portuguese Zone, which is considered to be underlain by Laurussia basement. The PLA stratigraphy most likely represents a synorogenic basin that records the closure of the Late Paleozoic Rheic Ocean and the amalgamation of Pangaea. The youngest formations of the PLA contain upper Devonian microfossils.The results obtained indicate that the detrital zircons from the PLA represent a wide range of Precambrian and Paleozoic crystallization ages. Recycling of older sedimentary units of the Late Ediacaran active margin (Cadomian/Pan-African orogenies) as well as of the Early Paleozoic rifting and passive margin (Rheic Ocean) stages, accounts for the older populations with North-Gondwana affinity (Cambrian, Neoproterozoic, Paleoproterozoic and Archean, with a gap of Mesoproterozoic-age). However, the Mesoproterozoic detrital zircon ages found in the greywackes of the Pulo do Lobo Formation (< 7%) that do not correspond to any substantial source within North-Gondwana, could come from recycled sedimentary deposits or from denudation of Grenville-age basement (Laurussia?). The more recent formations present in the northern limb (Ferreira-Ficalho Group) of the PLA show a significant age cluster in the upper Devonian (c. 378 Ma), whereas on the southern limb (Chança Group), samples have from base to top of the stratigraphic sequence: a minor age cluster in the middle Devonian (c. 390 Ma), a significant age cluster in upper Devonian (c. 380 Ma) and very significant age cluster in the upper Devonian (c. 372 Ma). The presence of middle-upper Devonian detrital zircons in combination with very low abundances of Mesoproterozoic detrital zircon suggests that the PLA sedimentary rocks were not derived from exotic sources but rather have a North-Gondwanan origin. The zircon population in the interval c. 390-380 Ma has no identified corresponding magmatic or stratigraphic source in SW Iberia. Considering that, during the development of the upper Devonian basins of SW Iberia, Laurussia basement was not exposed and that there was no magmatic arc on the North-Gondwana margin, we suggest that the c. 390- 380 Ma detrital zircons are most probably derived from denudation of a (intra-oceanic) magmatic arc related to the closure of the Rheic Ocean

Trait-based prediction of extinction risk

Species are declining and going extinct at unprecedented rates due to human activity. Understanding the drivers of extinction may help conservationists to proactively protect the species most in need. Species’ vulnerability to extinction has been hypothesised to be related to both their intrinsic biological traits and external human factors, often in synergy. In the past twenty years, many studies have compared the traits of threatened species to those of non-threatened species, within taxonomic groups. However, the literature in the topic has often focussed on few taxa or geographical realms, which has limited our capacity to find and understand general predictors and mechanisms of extinction. The primary aim of this dissertation is to identify which traits are related with extinction risk across the generality of life forms and geographical realms. To do so, I have applied a set of three distinct approaches: in Chapter I, I have identified gaps in research and synthesised past literature using a meta-analytical approach. Given the identified gaps and biases, in Chapter II I compiled a dataset including species from all realms and 15 taxonomic groups, to find predictors of extinction risk across taxa. Because traits and human threats are likely to interact, in Chapter III, I have implemented, tested, and analysed a virtual conceptual model to understand how different traits interact with the different threats to increase the extinction risk of species. The literature review of Chapter included 173 publications with most studies focussing on either mammal or bird taxa. The spatial extent of studies has also been narrow, with a very strong focus on the Palaearctic realm, particularly for invertebrate and plant groups. Body size was the most studied trait, followed by geographical range and fecundity. Among the top 10% studied traits, geographical range size had the greatest percentage of significant relationships with extinction risk. Meta-analyses were possible for geographical range size, habitat breadth and body size, with the first two being negatively related to extinction risk, and the third showing no consistent effect. In Chapter II, I compiled and analysed trait-extinction risk relationships for 10 traits, with a dataset consisting of 874 species evenly sampled from 15 taxonomic groups ranging from vertebrates, invertebrates, and plants. I identified narrow habitat breadth as a universal predictor of extinction risk across vertebrates, invertebrates, and plants. Long generation length, low fecundity, and large offspring size - characteristic of species with slow life cycles - and small climatic breadth were also identified as general predictors, but available data was limited and therefore results are not conclusive for these traits. Poor dispersal ability is a general predictor among invertebrates and plants, but not among vertebrates. The remaining traits (body size, microhabitat verticality, trophic level, and diet breadth) showed contrasting responses depending on the taxa. In the third Chapter, my aim was to understand how different anthropogenic drivers may impact species with different traits. I built a conceptual agent-based model with virtual organisms competing in a virtual environment for resources, upon which I simulated human threats. My model simulations showed that traits and threats interact in predictable ways. Namely, threats that directly increase the mortality of individuals - direct killing- have a higher impact on organisms with slow life cycles and poor dispersal ability. Threats decreasing the amount of habitat - habitat loss and fragmentation- negatively affect large sized, poorly fecund organisms. The effect on dispersal ability depends on the spatial configuration of the threat. Finally, threats decreasing habitat quality or the amount of resources available to organisms - habitat degradation and invaders - severely affect large, fast-lived, and highly fecund organisms. For a clearer picture on which traits predispose species to extinction, more data should be collected on underrepresented groups and regions, such as invertebrates, plants, and fungi in the tropics. Despite this shortcoming, in this thesis I demonstrate that some traits predispose species to and can be used as predictors of extinction. Species with narrow geographical and habitat breadths, two of the classical dimensions of rarity, are more at risk. Slow life cycles and narrow climatic breadths should also drive greater extinction risk. Other traits do not seem to have a general response but are taxon-dependent. Finally, intrinsic traits must in the future be studied considering anthropogenic threat types, as these two dimensions interact to drive species extinctions.Lajit vähenevät ja kuolevat sukupuuttoon ennennäkemättömällä nopeudella ihmisen toiminnan vuoksi. Sukupuuttoon johtavien syiden ymmärtäminen voi auttaa luonnonsuojelijoita suojelemaan uhanalaisimpia lajeja ennaltaehkäisevästi. Kuinka ja miksi eri lajit kuolevat herkemmin sukupuuttoon kuin toiset on oletettu liittyvän sekä lajien sisäisiin biologisiin ominaisuuksiin että ulkoisiin, ihmisistä riippuviin tekijöihin. Viimeisten 20 vuoden aikana monissa tutkimuksissa on verrattu uhanalaisten lajien ominaisuuksia ei-uhanalaisten lajien ominaisuuksiin eri taksonien sisällä. Aiheeseen liittyvä kirjallisuus on keskittynyt kuitenkin usein vain muutamaan taksoniin tai maantieteelliseen alueeseen, mikä on rajoittanut kykyämme löytää ja ymmärtää yleisiä, sukupuuttoon liittyviä ennusmerkkejä ja mekanismeja. Tutkielmani ensisijainen tavoite on tunnistaa, mitkä ominaisuudet liittyvät sukupuuttoriskiin kaikki elämänmuodot ja maantieteelliset alueet huomioiden. Tätä varten olen soveltanut kolmea erilaista lähestymistapaa: luvussa I olen tunnistanut aukkoja tutkimuksessa ja yhdistänyt aiemman kirjallisuuden tuloksia käyttämällä meta-analyyttista lähestymistapaa. Tunnistetut aukot ja vinoumat huomioiden olen luvussa II koonnut tietoaineiston, joka sisältää lajeja kaikilta alueilta ja 15 taksonomisesta ryhmästä selkärankaisten, selkärangattomien ja kasviryhmien joukosta, löytääkseni sukupuuttoriskin ennusmerkkejä eri taksoneissa. Koska lajiominaisuudet ja ihmisten aiheuttamat uhat ovat todennäköisesti vuorovaikutuksessa, olen luvussa III soveltanut, testannut ja analysoinut virtuaalista käsitemallia ymmärtääkseni, kuinka eri ominaisuudet ovat vuorovaikutuksessa eri uhkien kanssa kasvattaen lajien sukupuuttoriskiä. Aiempaan kirjallisuuteen tutustuminen vahvisti, että suurin osa tutkimuksista on keskittynyt nisäkkäisiin tai lintuihin, ja erityisesti selkärangattomien tai kasvien kohdalla ne ovat maantieteellisesti rajoittuneet palearktiseen alueeseen. Ylivoimaisesti eniten tutkittu ominaisuus oli ruumiinkoko, mitä seurasivat maantieteellinen alue ja hedelmällisyys. 10 prosentissa eniten tutkituista ominaisuuksista maantieteellisen levinneisyysalueen koko oli prosentuaalisesti merkittävin sukupuuttoriskiin vaikuttava seikka. Meta-analyysit olivat mahdollisia maantieteellisen levinneisyysalueen koon, elinympäristön laajuuden ja ruumiinkoon osalta. Kaksi ensimmäistä vaikuttivat negatiivisesti sukupuuttoriskiin, kolmannella ei puolestaan näyttänyt olevan johdonmukaista vaikutusta. Luvussa II kokosin ja analysoin ominaisuuksien ja sukupuuttoriskin suhdetta 10 ominaisuuden osalta. Tietoaineisto koostui 874 lajista, jotka on valittu tasaisesti 15 taksonomisesta, selkärankaisten, selkärangattomien ja kasvien ryhmästä. Havaitsin suppean elinympäristön olevan yleinen sukupuuttoriskin ennusmerkki niin selkärankaisten, selkärangattomien kuin kasvienkin kohdalla. Pitkä sukupolviväli, alhainen hedelmällisyys ja jälkeläisten suuri koko – mikä on ominaista lajeille, joiden elinkaari on hidas – sekä pieni ilmastollinen levinneisyys, vaikuttivat myös olevan yleisiä ennusmerkkejä. Tietoja oli käytettävissä kuitenkin rajoitetusti, joten tulokset eivät ole ratkaisevia näiden ominaisuuksien osalta. Selkärangattomien ja kasvien joukossa huono leviämiskyky oli yleinen ennusmerkki. Näin ei kuitenkaan ollut selkärankaisten keskuudessa. Jäljellä olevat ominaisuudet (ruumiinkoko, mikroelinympäristön vertikaalisuus, trofiataso ja ruokavalion laajuus) viittasivat päinvastaisiin tuloksiin taksonista riippuen. Kolmannessa luvussa tavoitteeni oli ymmärtää, kuinka erilaiset ihmisen aiheuttamat tekijät mahdollisesti vaikuttavat ominaisuuksiltaan erilaisiin lajeihin. Rakensin käsitteellisen, ainepohjaisen mallin, jossa virtuaaliset organismit kilpailevat resursseista virtuaalisessa ympäristössä ihmisten aiheuttamien uhkien ollessa läsnä. Mallisimulaationi osoittivat, että ominaisuudet ja uhat vaikuttavat toisiinsa ennustettavalla tavalla. Yksilöiden kuolleisuutta suoraan lisäävät uhat – suora tappaminen – vaikuttavat nimittäin enemmän sellaisiin organismeihin, joiden elinkaari on hidas ja leviämiskyky huono. Elinympäristöä pienentävät uhat – elinympäristön häviäminen ja pirstoutuminen – vaikuttavat negatiivisesti suurikokoisiin ja heikosti lisääntyviin organismeihin. Vaikutus leviämiskykyyn riippuu uhan spatiaalisesta rakenteesta. Elinympäristön laatua tai organismien käytettävissä olevien resurssien määrää heikentävät uhat – elinympäristön rappeutuminen ja vieraslajit – vaikuttavat erittäin paljon suurikokoisiin ja tehokkaasti lisääntyviin organismeihin, joiden elinkaari on nopea. Jotta saataisiin selkeämpi kuva siitä, mitkä ominaisuudet altistavat lajit sukupuuttoon kuolemiselle, pitäisi kerätä enemmän tietoa aliedustetuista ryhmistä ja alueista, kuten tropiikissa elävistä selkärangattomista, kasveista ja sienistä. Tästä vajavaisuudesta huolimatta osoitan tässä tutkielmassa, että tietyt ominaisuudet altistavat lajeja sukupuutolle ja että näitä ominaisuuksia voidaan käyttää ennustavina tekijöinä. Lajit, joiden maantieteellinen levinneisyys ja elinympäristö ovat suppeita, eli kaksi klassista, harvinaisuutta kuvaavaa piirrettä, ovat suuremmassa vaarassa. Myös elinkaareltaan hitaiden ja suppeilla ilmastoalueilla asuvien lajien sukupuuttoriski on suurempi. Muilla ominaisuuksilla ei näytä olevan yleistä vaikutusta, vaan ne riippuvat taksoneista. Luontaisia ominaisuuksia on tulevaisuudessa tutkittava antropogeeniset uhkatyypit huomioiden, koska nämä kaksi tekijää vaikuttavat yhdessä lajien sukupuuttoon

Corporate foresight: A bibliometric analysis on research trends

The pressure on companies, influenced by the rapid dissemination of technological innovations increased the volatility of business environments making difficult for companies to decide and act when faced with market uncertainties. Corporate foresight (CF) is a fundamental management tool, which has been object of study in recent decades. CF enables companies to achieve better market position, sustainable profits and ultimately provides competitive advantages in the medium/long term, while also dealing positively with uncertainty. This research aims to identify investigate trends in CF based on previous studies. From a query created in Web of Science (WoS), we obtained our initial data sample, comprised between the period 2001 to 2021. Thus, allowing us to study the frequency of publications and total citations, as well as descriptively study journals, authors, keywords, and references. We then carried out a bibliometric analysis using CiteSpace software to study research patterns and trends. The results of the bibliometric analysis suggest a progressive interest in open foresight and the opportunity for new explanatory research as a method for understanding and validating corporate foresight.A pressão influenciada pela célere disseminação das inovações tecnológicas aumentou a imprevisibilidade dos ambientes de negócio dificultando as capacidades de decisão e de atuação das empresas, quando confrontadas com incertezas de mercado. Corporate foresight (CF) é um instrumento de gestão fundamental, que tem sido objeto de estudo nas últimas décadas. O CF capacita as empresas com melhores posições de mercado e lucros sustentáveis lidando também com a incerteza o que e proporciona vantagens competitivas a médio-longo prazo. Este estudo tem como objetivo identificar tendências de investigação sobre CF tendo como base estudos anteriores. A partir de uma query criada no Web of Science (WoS) obtivemos a nossa amostra inicial de dados, compreendida entre o período de 2001 a 2021. Assim foi-nos permitido estudar a frequência de publicações e citações totais bem como, analisar descritivamente jornais, autores, palavras-chaves e referências. Posteriormente realizámos uma análise bibliométrica utilizando o software CiteSpace para examinar padrões e tendências de investigação. Os resultados da análise bibliométrica sugerem um progressivo interesse em open foresight e a oportunidade de novas investigações explanatórias como instrumento de compreensão e validação do corporate foresight

Biological traits interact with human threats to drive extinctions : A modelling study

How a particular threat influences extinction risk may depend on biological traits. Empirical studies relating threats and traits are needed, but data are scarce, making simulations useful. We implemented an ecoevolutionary model to analyse how five threat types influence the extinction risk of virtual organisms differing in body size, maturity age, fecundity, and dispersal ability. The model consisted of observing the evolutionary shift in the mean trait values of an assemblage of organisms when a threat was added into the virtual world where they lived. If a positive shift was found in trait values, we considered that the threat negatively influenced organisms with lower values for that trait. Direct killing mostly affected organisms with slow life cycles (slower-living) and poorly dispersive organisms. Habitat loss caused a reduction in the average dispersal ability of organisms. Habitat fragmentation caused an increase of average dispersal ability, and had a negative effect on larger, less fecund organisms. Habitat degradation and the introduction of invasive competitors had similar effects, mostly affecting large and fast-living organisms, with habitat degradation also affecting highly fecund and poorly dispersive organisms. These results agree with previous empirical studies in which larger, slower-lived, and less fecund organisms are more vulnerable to a greater range of threats. On the other hand, our results challenge two commonly seen hypotheses in the literature: that organisms with high dispersal ability fare well under any high habitat loss scenarios, and that fast-living, highly fecund organisms always do well during environmental change. Our study shows that highly dispersive organisms may be the losers when habitat loss removes large continuous areas of habitat, and fast-living and highly reproductive organisms may be the losers when resources or energy availability dwindle to very low levels. Most importantly, our study underpins the importance of considering the type of threat when analysing the relation between traits and extinction. Even in simple scenarios such as the ones modelled here, different threats lead to different, sometimes opposite, extinction probabilities according to the biological traits of organisms.Peer reviewe

~ 610 Ma: a critical age for the Iberian consolidation

AIMS OF THE MEETING: The scientific sessions will be focused on the Pan-African and Cadomian Orogenies recorded in North Africa and western Europe across the Ediacaran Cambrian transition and its bearing in the assembly and demise of Pannotia. Contributions dealing with structural, magmatic, provenance sources, palaeomagnetic, sedimentary, chronostratigraphic and radiometric constraints are particularly welcome. ORGANIZING COMMITTEE: J. Javier Álvaro, Instituto de Geociencias (CSIC-UCM), Spain Martim Chichorro, Universidade Nova de Lisboa, Portugal Gabriel Gutiérrez-Alonso, Universidad de Salamanca, Spain.ABSTRACT: Both the Pan-African orogenic cycle and the peri-Gondwanan Cadomian Orogeny took part in the global tectonic event that led to the rearrangement of Gondwana's west-northern block. An approach to determine the nature of Cadomian - Pan-African events using detrital zircons population from Neoproterozoic-Lower Paleozoic (rift-to-drift cycle) stratigraphic record in Iberian Massif is here discussed.info:eu-repo/semantics/publishedVersio

Scene understanding from 3D point clouds and RGB images for autonomous driving

Autonomous cars are often equipped with 3D data acquisition sensors and devices, e.g., LiDAR, which provide a 3D point cloud that describes the surroundings. Direct acquisition of 3D data from these sensors is commonly used for obstacle avoidance and mapping. Analysing 3D point clouds is complex since point clouds are unstructured, unordered, and contain a varying number of points. The most common approach used for scene understanding in images is the Convolutional Neural Network. Although CNNs achieve high performance in image analysis, they cannot be applied naturally on point clouds. Several methods for extending CNNs to 3D point cloud analysis have been proposed, such as rasterization into a 3D voxel grid to use directly a CNN or using a Graph Convolutional Network. The main goal of this dissertation is to study and compare different approaches for scene understanding from 3D point clouds within the scope of driving automation systems. Moreover, the project contemplates the study of sensor fusion approaches, namely how to combine 3D point clouds and images. In light of this, this project uses a sensor fusion technique called pointpainting, which uses images segmentation to enhance 3D object detection on point clouds

The Ediacaran-early Palaeozoic Cadomian zircon province fringing Northwest Gondwana

publishersversionpublishe

Foreword : the Ediacaran-early Palaeozoic Cadomian zircon province fringing Northwest Gondwana

This special issue grew out of the "The Panafrican and Cadomian orogenies in North Africa and western Europe" meeting, held online in June 2021. It includes a selection of contributions presented at the workshop with the aim of covering a broad range of challenges derived from the application of the Cadomian zircon province concept