1,087 research outputs found

    Composición elemental de otolitos revela áreas de desove separadas de la anchoveta, Engraulis ringens, en Chile central y en el norte de la Patagonia

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    The anchoveta (Engraulis ringens) is widely distributed throughout the Humboldt Current (4°30′-44°S). In recent years, its eggs and larvae have also been found inside fjords and channels of northern Patagonia, close to the southern limit of the central-south Chilean fishery zone. Currently, it is unclear whether these southern individuals constitute an independent subpopulation. This study analysed the elemental composition of otoliths from 102 specimens from central Chile and northern Patagonia using laser ablation inductively coupled plasma mass spectrometry. The results indicated that the elemental composition of the otolith cores (Mg, Pb, Zn, Ba) differed significantly between sites, revealing the existence of two discrete spawning zones, one in central Chile and one in northern Patagonia. However, the low significant differences of elemental signatures of otolith edges suggest that either individuals from both areas move between spawning areas and mix at certain periods of the year, or they represent pocket units that form part of a larger stock that moves along the coast.La anchoveta (Engraulis ringens), está ampliamente distribuida a lo largo de la Corriente de Humboldt (4°30′-44°S). En años recientes, sus huevos y larvas han sido encontradas dentro de fiordos y canales del norte de la Patagonia, cerca del límite sur de la zona de pesca centro-sur chilena. Actualmente, no está claro si estos individuos del sur constituyen una subpoblación independiente. Este estudio analiza la composición elemental de otolitos de 102 especímenes de Chile central y Patagonia norte utilizando Ablación Láser con Espectrometría de Masas con Plasma Acoplado Inductivamente. Los resultados indican que la composición elemental (Mg, Pb, Zn, Ba) de los centros de los otolitos difieren significativamente revelando la existencia de dos zonas discretas de desove, una en Chile central y la otra en la Patagonia norte. Sin embargo, las escasas diferencias en las señales de los elementos en los bordes de los otolitos sugieren que los individuos de ambas áreas pueden moverse entre zonas de desove y mezclarse en ciertos periodos del año, o bien, que ellos representan unidades pequeñas que forman parte de un stock mayor que se mueve a lo largo de la costa

    New Insights into the Distribution, Physiology and Life Histories of South American Galaxiid Fishes, and Potential Threats to this Unique Fauna

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    South American galaxiids occupy both Patagonia and the ichthyogeographic Chilean Province, encompassing glacial Andean deep lakes, shallow plateau lakes, reservoirs, short Pacific rivers and long Atlantic rivers. The total fish fauna includes 29 species, comprising Neotropical fishes (siluriforms and characids), galaxiids, percichthyids, atherinopsids and mugilids, two lamprey species, and several exotic fishes (salmonids, Gambusia spp. and common carp). The family Galaxiidae shares a common ancestry with the Gondwanan temperate fish fauna, played a major role in the post-glacial colonization of Andean lakes and streams, and contributes key species to the food webs. Galaxiid species occupy an enormous latitudinal gradient, show a wide variety of life history patterns and are the southernmost native freshwater fishes of the world. Knowledge of South American galaxiids has improved notably, but new challenges arise due to climate change, biological invasions, damming, aquaculture and contamination. In this changing environment, the future of South American galaxiids should be carefully considered as a legacy of the old Gondwana and a unique attribute of the freshwaters of southern South America.Fil: Cussac, Victor Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; ArgentinaFil: Barrantes, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Boy, Claudia Clementina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Górski, Konrad. Universidad Austral de Chile; ChileFil: Habit, Evelyn. Universidad de Concepción; ChileFil: Lattuca, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Rojo, Javier Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

    High trophic niche overlap between a native and invasive mink does not drive trophic displacement of the native mink during an invasion process

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    The pressure elicited by invasive species on native species significantly increases with the increase of the overlap of their ecological niches. Still, the specific mechanisms of the trophic displacement of native species during the invasion process are unclear. The effects of the invasive American mink (Neovison vison) on the critically endangered European mink (Mustela lutreola) was assessed by analyses of diet and niche overlap during the invasion process. To do this, the isotopic composition (δ13C and δ15N) of both species of mink and their four main types of prey was analysed. Significant trophic overlap between the native European mink and invasive American mink was found when they coexisted in sympatry. Furthermore, both mink species were characterised by significant individual variation in diet and no obvious change in diet of the native species in response to the arrival of the introduced species was observed. High niche overlap registered between both species in sympatry with no displacement in diet of the native mink in response to the arrival of the invasive mink is expected to have important consequences for the viability and conservation of the native mink populations, as it suggests high competitive pressure

    Impact of climatic fluctuations on commercial fisheries in the Paraná River along the last century

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    We analysed the effects of decadal and annual hydrologic fluctuations on freshwater fisheries catches in the Middle Paraná River for a period of six decades from the 1930s to the 1980s. We first analysed changes in the flow regime of the Paraná River for the period between 1930s and 1980s, with focus on the variations of the flood pulse. To build and compare flow typology among years, we used cluster analysis. Principal component analysis (PCA) was used to assess overall similarity of flows among years. The fisheries catch analysed (1935-1983) were obtained along this river corridor. The obtained data consisted of landing reports on monthly/annual catches (total and by species) in ports along the Paraná River. Differences in total catches among decades were tested using a one-way permutational analysis (PERMANOVA). The canonical analysis of the principal coordinates (CAP) was used to assess temporal patterns of similarity in fish catches per decades. To analysed the effects of flow regime variables on the variation of fish commercial catches we used distance-based redundancy analyses (dbRDAs). The climatic fluctuations in this period strongly affected the hydrology of the Middle Paraná River and the characteristics of its flow regime. The magnitude of floods as well as maximum, minimum and mean water levels increased progressively from 1930s until the 1980s concomitantly with increasing frequency and intensity of ENSO events that resulted in differentiation of distinct hydrological periods. The flood pulses were significantly more frequent and of greater magnitudes during the 1970s and 1980s. These large floods resulted in increased commercial fish catches in the 1980s, possibly due to enhanced recruitment. Specifically, large floods increased the commercial fish catches two years later. This effect was stronger for species that use floodplain habitats as areas of reproduction and larval nurseries, such as Prochilodus lineatus. We conclude that the natural flow regime of the Paraná River and perhaps other large subtropical rivers must be preserved in order to sustain their productive fisheries.Trabajo publicado en Acta Bioquímica Clínica Latinoamericana; no. 52, supl. 2, parte II, diciembre de 2018.Universidad Nacional de La Plat

    Budżetowanie działalności jednostek gospodarczych Teoria i praktyka. Część V

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    Z wprowadzenia: "Przekazujemy do rąk Czytelników część monografii dotyczącej budżetowania jednostek gospodarczych. Jej przygotowanie zbiegło się z ukazaniem się manifestu Precz z budżetami Jeremiego Норе’а i Robina Frasera. Autorzy poddają tam ostrej krytyce dotychczasowe praktyki stosowania budżetowania kosztowego. Stąd niniejsza publikacja - między innymi - dlatego różni się istotnie od poprzednich. Od pewnego czasu - także w Polsce - pojawiały się głosy wskazujące na istotne niedoskonałości budżetowania kosztowego, na przykład J. Gierusz [Materiały konferencyjne 2001], G. H. Świderska [Rachunkowośćzarządcza i rachunek kosztów, 2002]. Nie odnosiły one jednak skutku. Nie zauważono też dotąd narastającej listy zarzutów wytaczanych przeciw finansowym jednostkom miary stosowanym w budżetowaniu kosztowym, na przykład G. K. Świderska [jak wyżej], M. Sierpińska, B. Niedbała [Controllingoperacyjny wpnedsiębiorstwie, 2003]. Bez echa pozostało postawione przez autora pytanie: „zmierzch czy rozwój budżetowania?” [„Controlling i rachunkowość zarządcza” 9/2002], gdzie jednoznacznie wskazano, że budżetowanie kosztowe obejmuje jedynie jedną sferę działalności przedsiębiorstwa i tym samym nie może stanowić wystarczającej podstawy do sterowania przedsiębiorstwem. Zwolennicy budżetowania kosztowego nawet zgadzali się ze stawianymi zarzutami, jednak nie reagowali na propozycje zmian w filozofii i metodologii budżetowania."(...

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

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    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good
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