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Petrogenesis of Quebrada de la Mina and Altar North porphyries (Cordillera of San Juan, argentina): Crustal assimilation and metallogenic implications

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Geoscience Frontiers 2017年第5期8卷 1135-1159页

作者： laura Maydagán Marta Franchini Massimo Chiaradia Verónica Bouhier Noelia Di Giuseppe Roger Rey Luis Dimieri Centro Patagónico de Estudios Metalogenéticos-CONICET Argentina INGEOSUR-CONICET Departamento de Geología Universidad Nacional del Sur San Juan 670 8000 Bahía Blanca Argentina Instituto de Investigación en Paleobiología y Geología Universidad Nacional de Río Negro Av. Roca 1242 8332 Roca Argentina departamento de Geología y Petróleo Facultad de Ingeniería Universidad Nacional del Comahue Buenos Aires 1400 8300 Neuquén Argentina Section of Earth and Environmental Sciences University of Geneva Switzerland Minera Peregrine argentina S.A Santa Fe (Oeste) 117 Piso 4B Edificio Derby Ciudad San Juan Argentina

We investigate the geology of Altar North(Cu-Au) and Quebrada de la Mina(Au) porphyry deposits located in San Juan Province(argentina), close to the large Altar porphyry copper deposit(995 Mt,0.35% Cu, 0.083 g/t Au), to present constraints on the magmatic processes that occurred in the parental magma chambers of these magmatic-hydrothermal systems. Altar North deposit comprises a plagioclase-amphibole-phyric dacite intrusion(Altar North barren porphyry) and a plagioclaseamphibole-biotite-phyric dacite stock(Altar North mineralized porphyry, 11.98 ± 0.19 Ma). In Quebrada de la Mina, a plagioclase-amphibole-biotite-quartz-phyric dacite stock(QDM porphyry,11.91±0.33 Ma) crops out. High Sr/Y ratios(92-142) and amphibole compositions of Altar North barren and QDM porphyries reflect high magmatic oxidation states(fO_2= NNO+1.1 to+1.6) and high fH_2O conditions in their magmas. Zones and rims enriched in anorthite(An_(37-48))), SrO(0.22-0.33 wt.%)and FeO(0.21-0.37 wt.%) in plagioclase phenocrysts are evidences of magmatic recharge processes in the magma chambers. Altar North and Quebrada de la Mina intrusions have relatively homogeneous isotopic compositions(^(87)Sr/^(86)Sr_(t)= 0.70450-0.70466, ε_(ND)(t) = +0.2 to +1.2) consistent with mixed mantle and crust contributions in their magmas. Higher Pb isotopes ratios(^(207)Pb/^(204)Pb=15.6276-15.6294) of these intrusions compared to other porphyries of the district, reflect an increase in the assimilation of high radiogenic Pb components in the magmas. Ages of zircon xenocrysts(297,210,204,69 Ma) revealed that the magmas have experienced assimilation of Miocene, Cretaceous, Triassic and Carboniferous crustal *** that precipitated sulfides in the Altar deposit may have remobilized Pb from the host rocks, as indicated by the ore minerals being more radiogenic(207Pb/204 Pb = 15.6243-15.6269) than their host intrusions. Au/Cu ratio in Altar porphyries(average Au/Cu ratio of 0.14 ×10^(-4)by weight in Altar Central)is hig

关键词： Porphyry High sulfidation epithermal Magmatic recharge Radiogenic isotopes Crustal assimilation Argentinian Andes

The Gondwana Orogeny in northern North Patagonian Massif:Evidences from the Caita Có granite, la Se?a and Pangaré mylonites,argentina

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Geoscience Frontiers 2016年第4期7卷 621-638页

作者： Daniel A.Gregori Bernhardt Saini-Eidukat Leonardo Benedini Leonardo Strazzere Mercedes Barros José Kostadinoff Cátedra de Geología argentina Departamento de Geología Universidad Nacional del Sur and INGEOSUR department of Geosciences North Dakota State University Cátedra de Campos Gravitacionales Departamento de Física Universidad Nacional del Sur

Structural analyses in the northern part of the North Patagonia Massif, in the foliated Caita Co granite and in la Sefia and Pangare mylonites, indicate that the pluton was intruded as a sheet-like body into an opening pull-apart structure during the Gondwana Orogeny. Geochronological studies in the massif indicate a first, lower to middle Permian stage of regional deformation, related to movements during indentation tectonics, with emplacement of foliated granites in the western and central areas of the North Patagonian Massif. Between the upper Permian and lower Triassic, evidence indicates emplacement of undeformed granitic bodies in the central part of the North Patagonian Massif. A second pulse of deformation between the middle and upper Triassic is related to the emplacement of the Caita CO granite, the development of mylonitic belts, and the opening of the Los Menucos Basin. During this pulse of deformation, compression direction was from the eastern quadrant.

关键词： Gondwana Orogeny Northern Patagonia Foliated granite Mylonites argentina

Middle Eocene chondrichthyan fauna from Antarctic Peninsula housed in the Museo de la Plata,argentina

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Advances in Polar Science 2024年第1期35卷 14-47页

作者： Martina CHARNELLI Soledad GOUIRIC-CAVALLI Marcelo A.REGUERO Alberto L.CIONE Agencia Nacional de Promoción Científica y Tecnológica(ANPCyT) Godoy Cruz 2370Argentina División Paleontología Vertebrados Museo de La PlataPaseo del Bosque s/nLa Plata B1900FWAArgentina Facultad de Ciencias Naturales y Museo de la Plata(FCNyM) Universidad Nacional de La Plata(UNLP)La Plata CP 1900Argentina Instituto Antártico Argentino(IAA) General San Martín B1650HMKArgentina Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET) Buenos Aires C1425FQBArgentina

In recent years,the taxonomy and systematics of the cartilaginous fish taxa from the Eocene la Meseta Formation of Seymour(Marambio)Island,Antarctica have been extensively discussed in a series of papers,resulting in a complete revision of the Antarctic Eocene ichthyofauna housed in the Vertebrate Paleontology collection of the Museo de la Plata,*** collection constitutes one of the largest and taxonomically most diverse in the world,with approximately 20000 specimens,which provides a solid database used for the analysis of qualitative and quantitative chondrichthyan taxonomic *** information provided herein might be useful to understand the sudden decline in chondrichthyan taxonomic diversity towards the top of la Meseta Formation as well as its potential relationship with environmental changes during the Eocene.

关键词： Gondwana Antarctica Paleogene ichthyofauna Seymour(Marambio)Island

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Simplified Life Cycle Analysis: A Rural School in la Pampa, argentina

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American Journal of Climate Change 2014年第1期3卷 22-32页

作者： Mariela I. Marcilese Jorge D. Czajkowski laboratorio de Arquitectura y Hábitat Sustentable (layHS) Facultad de Arquitectura y Urbanismo (FAU) La Plata Argentina universidad Nacional de la Plata (UNLP) La Plata Argentina

This study case is a rural school in la Pampa, argentina, where we compare two energy efficiency systems for construction: the local traditional building type and a proposed one, based on passive system design during its life cycle. In addition, we assume that savings of emissions of greenhouse-gases are valued in terms of argentina’s energy matrix. The efficiency, in terms of energy, involves the consumption for its manufacture (extraction, transport and assembly of materials), construction, maintenance and dismantling, recycling and final disposal of waste. Knowing this information at the preliminary stage can be advantageous to evaluate the selected materials in terms of energy and cost savings to amortize its value over the life cycle, and introduce other types of design. At present, there are significant problems of resource scarcity. The implementation of the analysis of life cycle (LC) should be a significant contribution in the field of construction in reference to awareness about energy conservation and efficiency, and therefore contributing to the sustainable development of societies.

关键词： Energy Efficiency Rural School Life Cycle

Complementarity between quantum coherence and mixedness:a majorization approach

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Communications in Theoretical Physics 2023年第5期75卷 73-83页

作者： Yanet Alvarez Marcelo Losada Mariela Portesi Gustavo M Bosyk Instituto de Física la Plata CONICET–UNLP1900 La PlataArgentina Facultad de Ciencias Exactas Universidad Nacional de La Plata1900 La PlataArgentina Facultad de Matemática AstronomíaFísica y ComputaciónUniversidad Nacional de Córdoba5000 CórdobaArgentina

Quantum coherence is a relevant resource for various quantum information processing tasks,but it is fragile since it is generally affected by environmental *** is reflected in the loss of purity of the system,which in turn limits the amount of quantum coherence of *** a consequence,a complementarity relation between coherence and mixedness *** works characterize this complementarity through inequalities between theℓ1-norm of coherence and linear entropy,and between the relative entropy of coherence and von Neumann ***,coherence-mixedness complementarity is expected to be a general feature of quantum systems,regardless of the measures ***,an alternative approach to coherence-mixedness complementarity,based on majorization theory,is *** quantifiers of coherence and mixedness,namely the coherence vector and the spectrum,respectively,are used,instead of scalar measures.A majorization relation for the tensor product of both vectorial quantifiers is obtained,capturing general aspects of the trade-off between coherence and *** optimal bound for qubit systems and numerical bounds for qutrit systems are ***,coherence-mixedness complementarity relations are derived for a family of symmetric,concave and additive *** results provide a deeper insight into the relation between quantum coherence and mixedness.

关键词： coherence mixedness complementarity majorization

Trophic Status of Shallow lakes of la Pampa (argentina) and Its Relation with the land Use in the Basin and Nutrient Internal Load

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Journal of Environmental Protection 2013年第11期4卷 51-60页

作者： Santiago A. Echaniz Alicia M. Vignatti departamento de Ciencias Biológicas Facultad de Ciencias Exactas y Naturales Universidad Nacional de La Pampa Santa Rosa Argentina.

Phosphorus and nitrogen are essential nutrients for living organisms. Their concentration in the water of an aquatic ecosystem is one of the factors responsible for the trophic status of the lake and is related to the soils of the region and to the human activities carried out in their basins. These nutrients are also found in the bottom sediments, where they can either be retained or re-enter the water column. Since the information about the concentrations of nutrients in the water of some lakes of la Pampa (argentina) is fragmentary, the aim of this study is to describe the trophic status of some shallow lakes of the semiarid center of argentina and analyze its relation with the human activities in their basins, the concentrations of nutrients and organic matter and particle size distribution of sediments. To this end, we studied ten shallow lakes subjected to different anthropogenic influences (agriculture, agriculture and livestock and impacted by cities). All were hypertrophic and the concentrations of total phosphorus and total nitrogen were among the highest reported globally. Since some lakes had no fish, cladoceran grazing (top-down effect) led them have reduced concentrations of phytoplankton chlorophyll-a and high water transparency. This relativizes the use of these parameters to determine the trophic status. The sediments of seven of the studied lakes were predominated by fine sands, whereas three were predominated by silts. Nutrient and organic matter content were high, with higher concentrations in lakes with prevalence of fine particles. The reduced adsorption capacity of sediments, the resuspension by wind, the anthropogenic input and the accumulation favored by the arheic character of the basins would explain the high concentrations of nutrients in the water of these Pampean environments.

关键词： Eutrophication Trophic State Total Phosphorus Shallow lakes Internal Load land Use

Distal nucleotides affect the rate of stop codon read-through

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Quantitative Biology 2023年第1期11卷 44-58页

作者： Luciana I.Escobar Andres M.Alonso Jorge R.Ronderos Luis Diambra CREG Universidad Nacional de La Plata-CONICETLa Plata CP 1900Argentina INTechUniversidad Nacional de San MartinChascomus CP 7130Argentina FCNyMUniversidad Nacional de La PlataLa Plata CP 1900Argentina

Background:A key step in gene expression is the recognition of the stop codon to terminate translation at the correct ***,it has been observed that ribosomes can misinterpret the stop codon and continue the translation in the 3′UTR *** phenomenon is called stop codon read-through(SCR).It has been suggested that these events would occur on a programmed basis,but the underlying mechanisms are still not well ***:Here,we present a strategy for the comprehensive identification of SCR events in the Drosophila melanogaster transcriptome by evaluating the ribosomal density *** associated ribosomal leak rate was estimated for every event identified.A statistical characterization of the frequency of nucleotide use in the proximal region to the stop codon in the sequences associated to SCR events was ***:The results show that the nucleotide usage pattern in transcripts with the UGA codon is different from the pattern for those transcripts ending in the UAA codon,suggesting the existence of at least two mechanisms that could alter the translational termination ***,a linear regression models for each of the three stop codons was developed,and we show that the models using the nucleotides at informative positions outperforms those models that consider the entire sequence context to the stop ***:We report that distal nucleotides can affect the SCR rate in a stop-codon dependent manner.

关键词： translational readthrough stop codons translational termination ribosomal density profiles nucleotide usage frequency

Sudden openings and gradual closures in canopy cover modulate acclimation,survival,and growth of a shade-tolerant rainforest tree species

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Journal of Forestry Research 2024年第5期35卷 78-90页

作者： Ana Paula Moretti Flavia Yesica Olguin Juan Marcelo Gauna Corina Graciano INFIVE(CONICET-universidad Nacional de la Plata) Diagonal 113 N°4951900 La PlataProvincia de Buenos AiresArgentina CONICET Godoy Cruz 2290C1425FQB Buenos AiresArgentina Facultad de Ciencias Agrariasy Forestales Universidad Nacional de La PlataCalle 60y 1181900 La PlataProvincia de Buenos AiresArgentina Facultad de Ciencias Forestales Universidad Nacional de MisionesBertoni 124 km 33380 EldoradoProvincia de MisionesArgentina

Forest disturbances at gap levels are one of the most important events for the regeneration and establishment of intermediate tree *** canopy openings expose plants to high light intensity and high evaporative demands that stress shade-acclimated ***,the slow closure of gaps reduces light availability to plants established when the incident irradiation was *** work evaluated the morphological and physiological acclimation of Cabralea canjerana(Vell)*** to sudden and to gradual changes in canopy cover.A pot experiment was carried out with plants exposed to a sudden opening.A few days after the light shock,plants rapidly increased photosynthetic rates and decreased leaf water *** two months,plants activated physiological responses at leaf and whole plant levels to high light and water stresses,e.g.,increased stoma-tal conductance,stomatal index and reduction of leaf:fine roots ratio and *** seven months,hydraulic conductivity of petioles and the whole leaf increased,and growth was much higher than plants that remained under the *** a field experiment in gaps in the rainforest,plants acclimated to all canopy *** years after planting,growth was maximum in open environments within the gaps,even if the canopy closed during the first 20 months after *** conclusion,if this species is planted to enrich the rainforest,positions within gaps with lower canopy cover should be chosen and gap closure will not affect *** manage *** natural regeneration,the opening of gaps and removal of understory will increase survival and growth without the risk that the stress caused by these sudden openings could lead to the death of ***-bining pot and field experiments helps to understand the autecology of trees with particular ecological interest,and to build sound restoration practices.

关键词： Cabralea canjerana Atlantic forest Abiotic stress Regeneration Seedling

Distribution of action movements （DAM）： a descriptor for human action recognition

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Frontiers of Computer Science 2015年第6期9卷 956-965页

作者： Franco RONCHETTI Facundo QUIROGA laura laNZARINI Cesar ESTREBOU Instituto de Investigacion en Informatica III-LIDI Facultad de Informatica Universidad Nacional de La Plata La Plata B 1900AWX Argentina

Human action recognition from skeletal data is an important and active area of research in which the state of the art has not yet achieved near-perfect accuracy on many well- known datasets. In this paper, we introduce the Distribution of Action Movements descriptor, a novel action descriptor based on the distribution of the directions of the motions of the joints between frames, over the set of all possible mo- tions in the dataset. The descriptor is computed as a normal- ized histogram over a set of representative directions of the joints, which are in turn obtained via clustering. While the descriptor is global in the sense that it represents the overall distribution of movement directions of an action, it is able to partially retain its temporal structure by applying a window- ing scheme. The descriptor, together with performs several state-of-the-art known datasets. a standard classifier, out- techniques on many well-

关键词： human action recognition descriptor Prob-SOM MSRC12 Action3D