92 research outputs found

    Els estranys vertebrats de les Balears pre-humanes

    Get PDF
    La fauna vertebrada que va habitar les illes de Mallorca i Menorca abans de l'arribada de l'hom

    Significación sedimentológica y paleogeográfica del nivel arcilloso con corales del Senonuense superior de los alrededores de la Pobla de Segur (Prov. Lérida)

    Full text link
    There is in this note a facies description of the upper Cre- taceous clay levels with corals from Pobla de Segur surroundings and á sedimentological interpretation is give regardin, the regional paleogeographic evolution

    El medi lenític de S'Albufera de Mallorca

    Get PDF
    Al segle passat, i amb l'objectiu de dessecar S'Albufera, s'enturaren estanys i es construí un sistema de canals que condueixen les aigües de forma regular cap a la mar. El que abans era un gradient de divagació de les aigües amb poca energia potencial s'ha transformat en un dràstic gradient amb alguns estanys com l'estany de la Font de Sant Joan, el des Colombar, el des Cibollar, el des Ponts i petits estanys d'aigües intermitents que són objecte del present estudi. Els estanys presenten diferents propietats físico-quimiques i morfològiques i, en conseqüència, tenen un model de dinàmica anual particular. Exceptuant l'estany des Cibollar, altament eutròfic i meromiòtic, els estanys tenen una dinàmica dominada per process os naturals com ara canvis de salinitat i períodes de producció-descomposició. Es pot resumir la dinàmica de la manera següent: primaveres amb inici de producció i sota una creixent salinització. Estius productius i altament salinitzats. Tardors desalinitzades amb descomposició de la biomassa produïda a l'estiu. Hiverns relativament poc salinitzats i amb materia mineralitzada.In the last century and with the aims of dessication of the Albufera many lagoons were filled up and a canal system was made to lead waters directly to the sea. This change transformed a water dispersal gradient with low potential energy into a strong gradient with some ponds and lagoons, such as: Font de Sant Joan, Colombar lagoons, Cibollar, Ponts and small ponds with intermittent waters. The lagoons display different physico-chemical features and annual dynamics. With the exception of the Cibollar, which is strongly eutrophic and meromictic, the lagoons display natural dynamics such as changes in salinity and periods of production-decomposition. One may summarize as follows: spring seasons under the influence of the sea with incipient production, summer production with high salinity, desalinized autumns with decomposition of the summer production and low salinity winters with mineralized matter

    El medi lòtic de S'Albufera de Mallorca

    Get PDF
    Al segle passat, i amb l'objectiu de dessecar S'Albufera, s'enturaren estanys i es construí un sistema de canals que condueixen les aigües de forma regular cap a la mar. El que abans era un gradient de divagació de les aigües amb poca energia potencial s'ha transformat principalment en un sistema de canals on es pot veure un fort gradient físico-quimic, que va des de les aigües dolces enriquides en nitrogen de les parts altes properes als conreus, fins a les alques salinitzades i enriquides en fosfats a les parts baixes que comuniquen amb la mar i són pròximes a desenvolupaments urbanístics. Aquest gradient presenta un model general de dinàmica anual que es pot resumir de la manera següent: homogeneització autumnal de les característiques físico-quimiques del medi i, posteriorment, un lent període d'heterogeneització, que es maximitza durant l'estiu en els anys amb climatologia típica.In the last century and with the aims of dessication of the Albufera many lagoons were filled up and a canal system was made to drive the waters to the sea. A dispersal gradient of waters with low potential energy was changed in a canal system with strong physico-chemical gradient. These canals show a gradient from fresh waters enriched with N upstream near the farming area down to the saline phosphate-rich waters near the sea and adjoining an urban development. The annual cycle is characterized by an autumnal contraction reflecting homogeneization, followed by a phase of heterogeneization which peaks in the summer

    La vegetació aquàtica submergida de S'Albufera de Mallorca

    Get PDF
    Al segle passat, i amb l'objectiu de dessecar S'Albufera, s'enturaren estanys i es construí un sistema de canals que condueixen les aigües de forma regular cap a la mar: la majoria d'estanys del que actualment es parc natural quedaren dessecats. Actualment S'Albufera és un gradient ambiental amb diferents aportaments d'aigua. Consequentment, hi ha una diversitat d'hàbitats colonitzats per moltes espècies i és un lloc ideal per als estudis de les toleràncies ambientals de les espècies. S'estudiaren onze espècies de carofícies i deu de plantes vasculars submergides, respecte a set variables ambientals mitjançant un test de significació. Se n'obtingué una visió global mitjançant una anàlisi de components principals per a variables, les quals formen l'espai multidimensional on s'han projectat els hàbitats físico-químics de les espècies. D'aquesta anàlisi es poden extreure conclusions sobre les preferències d'hàbitat de les espècies, Nitellopsis obtusa, Tolypella glomerata, Chara globularis, C. connivens i C. aspera apareixen en aigües mesohalines, mesotròtiques 0 oligotròfiques. C. major i C. vulgaris accepten un cert nivell d'eutrofia i C galioides, C. hispida i C. canescens es presenten en llocs amb nivells baixos d'eutròfia. Lamprothamnium papulosum ocupa llocs altament salinitzats i poc eutrofitzats. A l'àrea d'estudi i en referència als paràmetres estudiats es pot dir que C. canescens, C. globularis, C. vulgaris, Tolypella glomerata, Lamprothamnium papulosum, C. hispida i C. galioides són espècies amb una tolerància global àmplia i C. connivens, Nitellopsis obtusa i C. major són molt menys tolerants. Myriophyllum spicatum, Najas marina, Potamogeton crispus, P. pectinatus i Zannichellia pedunculata són espècies àmpliament distribuïdes a S'Albufera. Ceratophyllum submersum i Ruppia maritima var. brevirrostris s'han de considerar estenoiques dins l'ambient d'estudi. La tolerància de Ceratophyllum submersum a la salinitat es significativament baixa mentre que la de Ruppia cirrhosa i R. maritima var. brevirrostris significativament alta. Ceratophyllum submersum té una distribució significativament negativa respecte a les altes concentracions de clorofil·la a fitoplanctònica i a les altes concentracions de fosfats. Ceratophyllum demersum i C. submersum es presenten principalment als llocs rics amb composts de nitrogen, mentre que Ruppia cirrhosa es presenta en llocs on hi ha baixes concentracions de nitrats a l'aigua.In the last century and with the aims of dessication of the S'Albufera were filled up many lagoons and a canal system was made. Now the S'Albufera is a graded system of coastal marshes with several sources of water input. Consequently there is a diversity of habitats colonized by many species and it is an ideal site for the study of environmental tolerances. Eleven species of Characeae and ten species of submerged vascular plants have been analyzed for seven environmental variables by means of a significance test. A synthetic view has been obtained through a principal component analysis for variables which form the multidimensional space where we project the species physico-chemical habitat. From such analysis we can obtain conclusions on the relative habitat preferences of the Characeae and of the submerged vascular plats of the S'Albufera. Nitellopsis obtusa, Tolypella glomerata, Chara globularis, C. connivens and C. aspera appear in mesohaline and mesotrophic or oligotrophic zones. C. major and C. vulgaris accept some degree of eutrophy and C galioides, C. hispida and C. canescens low levels of eutrophy. Lamprothamnium papulosum appears over strongly salinized sites which are poorly eutrophied. In the study area and in relation to parameters under study, we regard C. canescens, C. globularis, C. vulgaris, Tolypella glomerata, Lamprothamnium papulosum, C. hispida and C. galioides as species with a wide global tolerance and C. connivens, Nitellopsis obtusa and C. major as being decreasingly tolerant. Myriophyllum spicatum, Najas marina, Potamogeton crispus, P. pectinatus and Zannichellia pedunculata are widely distributed in the S'Albufera. Ceratophyllum submersum and Ruppia maritima var. brevirrostris are considered stenoic. The tolerance of Ceratophyllum submersum to salt is significantly low and that of Ruppia cirrhosa and R. maritima var. brevirrostris significantly high. Ceratophyllum submersum has a significantly negative distribution with regard to phytoplanctonic chlorophyll a and phosphate concentrations. Ceratophyllum demersum and C. submersum primarily occur in nitrate-rich waters whereas Ruppia cirrhosa primarily occurs in low nitrate waters

    Sex and age effects on monk parakeet home-range variation in the urban habitat

    Get PDF
    Home-range size is a key aspect of space-use, and variation in home-range size and structure may have profound consequences for the potential impact of damage and control strategies for invasive species. However, knowledge on home-range structure of naturalized parrot species is very limited. The aim of this study was to quantify patterns of home-range variation according to sex and age of the monk parakeet Myiopsitta monachus, an invasive parakeet in Europe. Mean kernel home-range size was 12.4 ± 1.22 ha (range 1.7–74.1 ha; N = 73 birds). Juveniles had a larger home-range size than adults, but sexes did not differ in kernel home-range size. The mean maximum distance moved by monk parakeets was 727 ± 37.0 m (range: 150–1581 m), and it was not dependent on either the sex or age of the birds. Having a small home range is one of the conditions for the feasible eradication of an invasive species; hence, the small home range of urban monk parakeets that we report here is good news for pest managers. However, this small home-range size can limit the effectiveness of culling operations with traps or feeders with contraceptives or poison, and other alternatives, such as funnel nets or traps, should be used

    Early Origin for Human-Like Precision Grasping: A Comparative Study of Pollical Distal Phalanges in Fossil Hominins

    Get PDF
    Altres ajuts: Generalitat de Catalunya 2006 FI 00065 i beca de viatge 2008 BE1 00370Background: The morphology of human pollical distal phalanges (PDP) closely reflects the adaptation of human hands for refined precision grip with pad-to-pad contact. The presence of these precision grip-related traits in the PDP of fossil hominins has been related to human-like hand proportions (i.e. short hands with a long thumb) enabling the thumb and finger pads to contact. Although this has been traditionally linked to the appearance of stone tool-making, the alternative hypothesis of an earlier origin-related to the freeing of the hands thanks to the advent of terrestrial bipedalism-is also possible given the human-like intrinsic hand proportion found in australopiths. - Methodology/Principal Findings: We perform morphofunctional and morphometric (bivariate and multivariate) analyses of most available hominin pollical distal phalanges, including Orrorin, Australopithecus, Paranthropous and fossil Homo, in order to investigate their morphological affinities. Our results indicate that the thumb morphology of the early biped Orrorin is more human-like than that of australopiths, in spite of its ancient chronology (ca. 6 Ma). Moreover, Orrorin already displays typical human-like features related to precision grasping. - Conclusions: These results reinforce previous hypotheses relating the origin of refined manipulation of natural objects-not stone tool-making-with the relaxation of locomotor selection pressures on the forelimbs. This suggests that human hand length proportions are largely plesiomorphic, in the sense that they more closely resemble the relatively short-handed Miocene apes than the elongated hand pattern of extant hominoids. With the advent of terrestrial bipedalism, these hand proportions may have been co-opted by early hominins for enhanced manipulative capabilities that, in turn, would have been later co-opted for stone tool-making in the genus Homo, more encephalized than the previous australopiths. This hypothesis remains may be further tested by the finding of more complete hands of unequivocally biped early hominins

    Chronicle of an early demise, surname extinction in the fifteenth and the seventeenth centuries

    Get PDF
    This is the Author’s Original Manuscript of an article published by Taylor & Francis in Historical Methods: A Journal of Quantitative and Interdisciplinary History on 2018, available online: http://www.tandfonline.com/10.1080/01615440.2018.1462747It has been amply demonstrated that individuals' reproductive capability is the key explanatory phenomenon for understanding onomastic disappearance during the early modern period. This article analyzes the evolution and consequences of surname extinction in a specific population: Catalonia in the sixteenth and seventeenth centuries. In this article two aspects are examined. First, the observed disappearance of surnames is estimated through historical data collected in the Llibres d'Esposalles (Marriage Books) from 1481 to 1600 at Barcelona Cathedral. Second, the estimated natural extinction of those surnames registered in 1481 is forecast by applying a statistical branching processResearch has been funded by Projects MTM2016-76969-P (Spanish State Research Agency, AEI) and MTM2013-41383-P (Spanish Ministry of Economy, Industry and Competitiveness), both co-funded by the European Regional Development Fund (ERDF), IAP network from Belgian Science Policy. Work of J. Ameijeiras-Alonso has been supported by the Ph.D. Grant BES-2014-071006 from the Spanish Ministry of Economy, Industry and CompetitivenessNO
    corecore