Analysis of admixture and genetic structure of two Native American groups of Southern Argentinean Patagonia.

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Sala, Andrea; Corach, Daniel

2014-03-01

Argentinean Patagonia is inhabited by people that live principally in urban areas and by small isolated groups of individuals that belong to indigenous aboriginal groups; this territory exhibits the lowest population density of the country. Mapuche and Tehuelche (Mapudungun linguistic branch), are the only extant Native American groups that inhabit the Argentinean Patagonian provinces of Río Negro and Chubut. Fifteen autosomal STRs, 17 Y-STRs, mtDNA full length control region sequence and two sets of Y and mtDNA-coding region SNPs were analyzed in a set of 434 unrelated individuals. The sample set included two aboriginal groups, a group of individuals whose family name included Native American linguistic root and urban samples from Chubut, Río Negro and Buenos Aires provinces of Argentina. Specific Y Amerindian haplogroup Q1 was found in 87.5% in Mapuche and 58.82% in Tehuelche, while the Amerindian mtDNA haplogroups were present in all the aboriginal sample contributors investigated. Admixture analysis performed by means of autosomal and Y-STRs showed the highest degree of admixture in individuals carrying Mapuche surnames, followed by urban populations, and finally by isolated Native American populations as less degree of admixture. The study provided novel genetic information about the Mapuche and Tehuelche people and allowed us to establish a genetic correlation among individuals with Mapudungun surnames that demonstrates not only a linguistic but also a genetic relationship to the isolated aboriginal communities, representing a suitable proxy indicator for assessing genealogical background.

Nuevas citas de Coleoptera acuáticos y Megaloptera para la provincia de Chubut (Argentina New records of aquatic Coleoptera and Megaloptera from Chubut province (Argentina

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Miguel Archangelsky

2004-12-01

Full Text Available Se informa acerca de nuevos hallazgos de coleópteros acuáticos, de Dytiscidae, Gyrinidae, Hydrophilidae y Elmidae para la provincia de Chubut (Argentina. También se cita por primera vez a las Sialidae (Megaloptera, género Protosialis Weele, para la República Argentina.New records of aquatic Coleoptera, in the families Dytiscidae, Gyrinidae, Hydrophilidae and Elmidae, are reported for the Chubut province (Argentina. The Sialidae (Megaloptera, genus Protosialis Weele, is reported for the first time in Argentina.

A Tenebrionid beetle's dataset (Coleoptera, Tenebrionidae) from Peninsula Valdés (Chubut, Argentina).

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Cheli, Germán H; Flores, Gustavo E; Román, Nicolás Martínez; Podestá, Darío; Mazzanti, Renato; Miyashiro, Lidia

2013-12-18

The Natural Protected Area Peninsula Valdés, located in Northeastern Patagonia, is one of the largest conservation units of arid lands in Argentina. Although this area has been in the UNESCO World Heritage List since 1999, it has been continually exposed to sheep grazing and cattle farming for more than a century which have had a negative impact on the local environment. Our aim is to describe the first dataset of tenebrionid beetle species living in Peninsula Valdés and their relationship to sheep grazing. The dataset contains 118 records on 11 species and 198 adult individuals collected. Beetles were collected using pitfall traps in the two major environmental units of Peninsula Valdés, taking into account grazing intensities over a three year time frame from 2005-2007. The Data quality was enhanced following the best practices suggested in the literature during the digitalization and geo-referencing processes. Moreover, identification of specimens and current accurate spelling of scientific names were reviewed. Finally, post-validation processes using DarwinTest software were applied. Specimens have been deposited at Entomological Collection of the Centro Nacional Patagónico (CENPAT-CONICET). The dataset is part of the database of this collection and has been published on the internet through GBIF Integrated Publishing Toolkit (IPT) (http://data.gbif.org/datasets/resource/14669/). Furthermore, it is the first dataset for tenebrionid beetles of arid Patagonia available in GBIF database, and it is the first one based on a previously designed and standardized sampling to assess the interaction between these beetles and grazing in the area. The main purposes of this dataset are to ensure accessibility to data associated with Tenebrionidae specimens from Peninsula Valdés (Chubut, Argentina), also to contribute to GBIF with primary data about Patagonian tenebrionids and finally, to promote the Entomological Collection of Centro Nacional Patagónico (CENPAT

A Tenebrionid beetle’s dataset (Coleoptera, Tenebrionidae from Peninsula Valdés (Chubut, Argentina

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German Cheli

2013-12-01

Full Text Available The Natural Protected Area Peninsula Valdés, located in Northeastern Patagonia, is one of the largest conservation units of arid lands in Argentina. Although this area has been in the UNESCO World Heritage List since 1999, it has been continually exposed to sheep grazing and cattle farming for more than a century which have had a negative impact on the local environment. Our aim is to describe the first dataset of tenebrionid beetle species living in Peninsula Valdés and their relationship to sheep grazing. The dataset contains 118 records on 11 species and 198 adult individuals collected. Beetles were collected using pitfall traps in the two major environmental units of Peninsula Valdés, taking into account grazing intensities over a three year time frame from 2005–2007. The Data quality was enhanced following the best practices suggested in the literature during the digitalization and geo-referencing processes. Moreover, identification of specimens and current accurate spelling of scientific names were reviewed. Finally, post-validation processes using DarwinTest software were applied. Specimens have been deposited at Entomological Collection of the Centro Nacional Patagónico (CENPAT-CONICET. The dataset is part of the database of this collection and has been published on the internet through GBIF Integrated Publishing Toolkit (IPT (http://data.gbif.org/datasets/resource/14669/. Furthermore, it is the first dataset for tenebrionid beetles of arid Patagonia available in GBIF database, and it is the first one based on a previously designed and standardized sampling to assess the interaction between these beetles and grazing in the area. The main purposes of this dataset are to ensure accessibility to data associated with Tenebrionidae specimens from Peninsula Valdés (Chubut, Argentina, also to contribute to GBIF with primary data about Patagonian tenebrionids and finally, to promote the Entomological Collection of Centro Nacional Patag

A Tenebrionid beetle’s dataset (Coleoptera, Tenebrionidae) from Peninsula Valdés (Chubut, Argentina)

Science.gov (United States)

Cheli, Germán H.; Flores, Gustavo E.; Román, Nicolás Martínez; Podestá, Darío; Mazzanti, Renato; Miyashiro, Lidia

2013-01-01

Abstract The Natural Protected Area Peninsula Valdés, located in Northeastern Patagonia, is one of the largest conservation units of arid lands in Argentina. Although this area has been in the UNESCO World Heritage List since 1999, it has been continually exposed to sheep grazing and cattle farming for more than a century which have had a negative impact on the local environment. Our aim is to describe the first dataset of tenebrionid beetle species living in Peninsula Valdés and their relationship to sheep grazing. The dataset contains 118 records on 11 species and 198 adult individuals collected. Beetles were collected using pitfall traps in the two major environmental units of Peninsula Valdés, taking into account grazing intensities over a three year time frame from 2005–2007. The Data quality was enhanced following the best practices suggested in the literature during the digitalization and geo-referencing processes. Moreover, identification of specimens and current accurate spelling of scientific names were reviewed. Finally, post-validation processes using DarwinTest software were applied. Specimens have been deposited at Entomological Collection of the Centro Nacional Patagónico (CENPAT-CONICET). The dataset is part of the database of this collection and has been published on the internet through GBIF Integrated Publishing Toolkit (IPT) (http://data.gbif.org/datasets/resource/14669/). Furthermore, it is the first dataset for tenebrionid beetles of arid Patagonia available in GBIF database, and it is the first one based on a previously designed and standardized sampling to assess the interaction between these beetles and grazing in the area. The main purposes of this dataset are to ensure accessibility to data associated with Tenebrionidae specimens from Peninsula Valdés (Chubut, Argentina), also to contribute to GBIF with primary data about Patagonian tenebrionids and finally, to promote the Entomological Collection of Centro Nacional Patag

Using dental enamel wrinkling to define sauropod tooth morphotypes from the Cañadón Asfalto Formation, Patagonia, Argentina.

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Femke M Holwerda

Full Text Available The early Middle Jurassic is regarded as the period when sauropods diversified and became major components of the terrestrial ecosystems. Not many sites yield sauropod material of this time; however, both cranial and postcranial material of eusauropods have been found in the Cañadón Asfalto Formation (latest Early Jurassic-early Middle Jurassic in Central Patagonia (Argentina, which may help to shed light on the early evolution of eusauropods. These eusauropod remains include teeth associated with cranial and mandibular material as well as isolated teeth found at different localities. In this study, an assemblage of sauropod teeth from the Cañadón Asfalto Formation found in four different localities in the area of Cerro Condor (Chubut, Argentina is used as a mean of assessing sauropod species diversity at these sites. By using dental enamel wrinkling, primarily based on the shape and orientation of grooves and crests of this wrinkling, we define and describe three different morphotypes. With the exception of one taxon, for which no cranial material is currently known, these morphotypes match the local eusauropod diversity as assessed based on postcranial material. Morphotype I is tentatively assigned to Patagosaurus, whereas morphotypes II and III correspond to new taxa, which are also distinguished by associated postcranial material. This study thus shows that enamel wrinkling can be used as a tool in assessing sauropod diversity.

Using dental enamel wrinkling to define sauropod tooth morphotypes from the Cañadón Asfalto Formation, Patagonia, Argentina.

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Holwerda, Femke M; Pol, Diego; Rauhut, Oliver W M

2015-01-01

The early Middle Jurassic is regarded as the period when sauropods diversified and became major components of the terrestrial ecosystems. Not many sites yield sauropod material of this time; however, both cranial and postcranial material of eusauropods have been found in the Cañadón Asfalto Formation (latest Early Jurassic-early Middle Jurassic) in Central Patagonia (Argentina), which may help to shed light on the early evolution of eusauropods. These eusauropod remains include teeth associated with cranial and mandibular material as well as isolated teeth found at different localities. In this study, an assemblage of sauropod teeth from the Cañadón Asfalto Formation found in four different localities in the area of Cerro Condor (Chubut, Argentina) is used as a mean of assessing sauropod species diversity at these sites. By using dental enamel wrinkling, primarily based on the shape and orientation of grooves and crests of this wrinkling, we define and describe three different morphotypes. With the exception of one taxon, for which no cranial material is currently known, these morphotypes match the local eusauropod diversity as assessed based on postcranial material. Morphotype I is tentatively assigned to Patagosaurus, whereas morphotypes II and III correspond to new taxa, which are also distinguished by associated postcranial material. This study thus shows that enamel wrinkling can be used as a tool in assessing sauropod diversity.

Presence of Arctotherium (Carnivora, Ursidae, Tremarctinae in a pre-cultural level of Baño Nuevo-1 cave (Central Patagonia, Chile

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López Mendoza, P.

2015-12-01

Full Text Available The description of an I3 assigned to Arctotherium sp. obtained from the Baño Nuevo-1 site (Central Patagonia, Chile is presented. The finding was recovered from Layer 5 and it is associated to Macrauchenia sp., Lama guanicoe, Felidae, Camelidae, Equidae and Mylodontidae, within a sterile deposit of cultural material, dated between ca. 13.500 and 11.200 BP. Despite the fact that it is only a single specimen, such finding extends the known distribution for the genus in Chile.Se presenta la descripción de un I3 asignado a Arctotherium sp. proveniente del sitio Baño Nuevo-1 (Patagonia Central, Chile. El hallazgo fue realizado en la Capa 5 y está asociado a restos de Macrauchenia sp., Lama guanicoe, Felidae, Camelidae, Equidae y Mylodontidae dentro de un depósito estéril de material cultural, datado entre los ca. 13.500 y 11.200 años AP. Aunque se trata de un único espécimen, amplía el rango de distribución conocido para este género en Chile.

Patagonia

DEFF Research Database (Denmark)

O'Rourke, Dara; Strand, Robert

2017-01-01

.” Specifically, this case study focuses on Patagonia’s durable water repellent (DWR) problem. DWR is a highly effective chemical treatment used to waterproof jackets (supporting the quality objective) but has by-products that are toxic and persist in the environment (undermining the sustainability objective......This article examines the tensions that arise when Patagonia simultaneously pursues sustainability and quality objectives embedded within its mission statement: “Build the best product, cause no unnecessary harm, use business to inspire and implement solutions to the environmental crisis......). This case explores the challenges Patagonia has faced and presents some creative solutions to them....

Un primitivo Notonychopidae (Litopterna del Paleoceno inferior de Punta Peligro, Chubut, Argentina

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Morales, J.

1997-12-01

Full Text Available The discovery of a new ungulate species, Requisia vidmari gen. nov., nov. sp. in the lower Paleocene of Punta Peligro, Chubut (Argentine represents the earliest known record of Litopterna. The dental morphology of this new genus is very similar to that known for Notonychops powelli Soria, 1989, differing mainly by its more primitive M3, which is less elongated and less selenodont. Requisia vidmari, together with Wainka tshotshe Simpson, 1948, can be included in the family Notonychopidae, which appear to represent an ancestral grade in the evolution of Litopterna. Because cladogenesis of South American ungulates clearly took place prior to the Punta Peligro fauna and was apparently rapid, phylogenetic interpretation is difficult.Se comunica un nuevo ungulado con dentición pre-selenodonta del Paleoceno inferior, Peligrense, de Patagonia, Argentina. Su morfología dentaria es muy similar a la de Notonychops powelli Soria, 1989, pero con caracteres más primitivos. La morfología de las cúspides, el tipo de desgaste y los caracteres crescentiformes del M3 indican que Requisia vidmari gen. nov., sp. nov. presenta fuertes evidencias del desarrollo de caracteres selenodontos, por lo que se lo considera como el más primitivo representante del orden Litopterna. Requisia vidmari y probablemente Wainka tshotshe Simpson, 1948, son primitivos en relación a Notonychops, pero su similitud morfológica justificaría su inclusión en la misma familia Notonychopidae. Se considera que la radiación adaptativa de los ungulados paleocenos de América del Sur fue precoz, eventualmente rápida, lo que dificulta encontrar un modelo filogenético suficientemente explicativo.

Paleontology, sedimentology and paleoenvironment of a new fossiliferous locality of the Jurassic Cañadón Asfalto Formation, Chubut Province, Argentina

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Gallego, Oscar F.; Cabaleri, Nora G.; Armella, Claudia; Volkheimer, Wolfgang; Ballent, Sara C.; Martínez, Sergio; Monferran, Mateo D.; Silva Nieto, Diego G.; Páez, Manuel A.

2011-02-01

A new Late Jurassic assemblage of “conchostracans”, ostracods, bivalves and caddisfly cases from the locality “Estancia La Sin Rumbo”, Chubut Province (Patagonia, Argentina) is recorded. The fossils occur in the upper part of an outcropping 45 m thick volcaniclastic lacustrine sequence of yellowish tuffs and tuffites of the Puesto Almada Member, which is the upper member of the Cañadón Asfalto Formation with U/Pb age of 161 ± 3 Ma. The sequence represents one sedimentary cycle composed of a (lower) hemicycle of expansion and a (higher) hemicycle of contraction of the water body. The invertebrates lived in small freshwater bodies during the periods of expansion of the lake. The occurrence of a great number of small spinicaudatans, associated with mud-cracks, is evidence of dry climatic conditions and suggests several local mortality events. The spinicaudatan record of the fushunograptid-orthestheriid (component of the Eosestheriopsis dianzhongensis fauna) and the presence of Congestheriella rauhuti Gallego and Shen, suggest a Late Jurassic (Oxfordian to Tithonian) age. Caddisfly cases are recorded for the first time in the Cañadón Asfalto Basin.

Aeolian sediment mass fluxes on a sandy soil in Central Patagonia

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Sterk, G.; Parigiani, J.; Cittadini, E.; Peters, P.; Scholberg, J.; Peri, P.

2012-01-01

The climate of Patagonia is semi-arid and characterised by frequent strong winds. Wind erosion is potentially a serious soil degradation process that impacts long-term sustainability of local agricultural systems, but the conditions and the rates of wind erosion in this region have not been

FRUPAT: A Tool to Quantify Inputs and Outputs of Patagonian Fruit Production Systems

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Cittadini, E.D.; Keulen, van H.; Peri, P.L.

2006-01-01

A software called FRUPAT was developed for calculating input and output coefficients (Technical Coefficients) of fruit production systems in South Patagonia. FRUPAT combined locations (Río Chubut valley; Sarmiento valley; Los Antiguos valley; Río Chico valley), edaphic environment (good quality soil

Selected contributions from the 9th International Conference on Tidal Sedimentology, November 2015, Puerto Madryn, Patagonia, Argentina: an introduction

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Scasso, Roberto A.; Cuitiño, José I.

2017-08-01

This special issue of Geo-Marine Letters presents selected contributions from the 9th International Conference on Tidal Sedimentology held on 17-19 November 2015 in Puerto Madryn, Chubut Province, Patagonia, Argentina. The guest editors are the conference organizers Roberto A. Scasso and José I. Cuitiño. Gerardo M. Perillo was the head of the Scientific Committee. The conferences on tidal sedimentology have been traditionally held every 4 years. However, only 3 years separated the last conference held in Caen (France, 2012) from this conference. Increasing numbers of contributions and the growing interest in tidal sedimentation have been the reasons for shortening the inter-conference period. The 2015 conference served as a discussion forum focusing on advances in modern and ancient tidal sedimentation at different locations worldwide. The papers presented in this Special Issue provide a selective view of the latest research results, the main topics dealing with tidal hydrodynamics and sediment transport, tidal coastal morphodynamics, modern and ancient tidal sedimentation, geotechnical processes in tidal environments, and tidal basins, facies and reservoirs.

Spatial distribution, feeding and length–mass relationships of Diamphipnopsis samali (Plecoptera, Diamphipnoidae in a North Patagonia Andean stream, Argentina

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Guillermo H. OMAD

2015-01-01

Full Text Available RESUMEN. Fueron estudiados algunos aspectos de la biología y ecología (patrones de distribución espacial, hábitos alimenticios y relación largo-masa de una población de Diamphipnopsis samali en un arroyo de primer orden que atraviesa un bosque exótico de pino en el centro-norte de Patagonia (Chubut, Argentina. Dos series de muestreos fueron realizados durante períodos de aguas altas y aguas bajas. Toda la información fue tratada con ANOVAS de dos factores y efectos fijos para evaluar diferencias significativas. El análisis de las piezas bucales de D. samali indica que corresponden a un tipo intermedio entre el tipo carnívoro y herbívoro-detritívoro. El contenido estomacal muestra que esta especie se alimenta de hifas fúngicas y madera, aunque en los estadios tempranos se encuentran restos de insectos. No se hallaron diferencias significativas en la alimentación entre períodos de aguas altas y aguas bajas, sin embargo, existieron diferencias significativas entre la dieta de larvas grandes y pequeñas. Fue clara la preferencia por el sustrato tronco y cascada, y también significativamente diferente entre los tipos pozón y corredera. No hubo diferencias significativas en la elección de hábitat entre los períodos de aguas bajas y aguas altas. Esta especie endémica de Patagonia parece estar bien adaptada a la presencia de un bosque ripario exótico, utilizando los troncos caídos como alimento y refugio.

Mortalidad en la población galesa de Gaiman, provincia de Chubut, Argentina

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Caratini, Alicia Liliana

2005-01-01

Full Text Available El objetivo de este trabajo es analizar la evolución en el tiempo de las defunciones y de las causas de muerte por edad y sexo de la población galesa de Gaiman, provincia de Chubut, Argentina. Los datos fueron obtenidos de las Actas de Defunción del Archivo del Registro Civil de la ciudad de Rawson, Chubut. El período de estudio se extendió de 1892 a 1961 y para su descripción y análisis se lo dividió en decenios. Se registraron 2103 defunciones de las cuales 1039 (49% correspondieron a galeses y sus descendientes, lo cual representa un promedio de 14.6 muertes por año. Se detectó una sobremortalidad masculina (59%, esperable en una población colonizadora con predominio de varones. Se observó un incremento, en el tiempo, de la edad media de defunción, lo que indica mejoras en las condiciones socioeconómicas y de salud de la población. La mortalidad infantil y los natimortos representaron el 20% y el 11%, respectivamente, de las defunciones y se constató una transición desde una mortalidad provocada por enfermedades de naturaleza exógena a otra de causalidad endógena. Al compararse nuestros datos con los de la provincia de Chubut y el país, se comprobó, en todos los casos, un descenso de la mortalidad en el tiempo, aunque en Gaiman esa disminución fue más significativa, probablemente por la atención que la comunidad le dedicaba a la educación y a la salud.

Holocene Dynamics of Temperate Rainforests in West-Central Patagonia

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Virginia Iglesias

2018-01-01

Full Text Available Analyses of long-term ecosystem dynamics offer insights into the conditions that have led to stability vs. rapid change in the past and the importance of disturbance in regulating community composition. In this study, we (1 used lithology, pollen, and charcoal data from Mallín Casanova (47°S to reconstruct the wetland, vegetation, and fire history of west-central Patagonia; and (2 compared the records with independent paleoenvironmental and archeological information to assess the effects of past climate and human activity on ecosystem dynamics. Pollen data indicate that Nothofagus-Pilgerodendron forests were established by 9,000 cal yr BP. Although the biodiversity of the understory increased between 8,480 and 5,630 cal yr BP, forests remained relatively unchanged from 9,000 to 2,000 cal yr BP. The charcoal record registers high fire-episode frequency in the early Holocene followed by low biomass burning between 6,500 and 2,000 cal yr BP. Covarying trends in charcoal, bog development, and Neoglacial advances suggest that climate was the primary driver of these changes. After 2,000 cal yr BP, the proxy data indicate (a increased fire-episode frequency; (b centennial-scale shifts in bog and forest composition; (c the emergence of vegetation-fire linkages not recorded in previous times; and (d paludification in the last 500 years possibly associated with forest loss. Our results therefore suggest that Nothofagus-Pilgerodendron dominance was maintained through much of the Holocene despite long-term changes in climate and fire. Unparalleled fluctuations in local ecosystems during the last two millennia were governed by disturbance-vegetation-hydrology feedbacks likely triggered by greater climate variability and deforestation.

Variation in the proximate composition and fatty acid profile recovered from Argentine hake (Merluccius hubbsi) waste from Patagonia

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Cretton, M.; Rost, E.; Mazzuca-Sobczuk, T.; Mazzuca, M.

2016-07-01

The fish processing operations in Patagonia produce large amounts of waste. The main fishery resource in Argentina is the Argentine hake (Merluccius hubbsi). The ports of the province of Chubut (the most important of which are Puerto Madryn, Rawson and Comodoro Rivadavia), together with Caleta Paula Port (province of Santa Cruz), in the Argentine Patagonia, capture more than 82,000 tons of hake annualy, 80% of which are of M. hubbsi, which is mostly converted into fillets. From this capture, about 2,296 tons of liver would be available for the extraction of oil. To promote the recovery and industrial use of fish oil, in the present study, we determined the variation in the proximate composition and fatty acid profile of Argentine hake waste from the ports mentioned above at different catch times. Proximate composition was determined according of the Official Methods of Analysis (AOAC). Fatty acid profile was analyzed by gas chromatography of the fatty acid methyl esters (FAMEs). A standard mixture of FAMEs was run under identical conditions to identify the compounds on the basis of their retention times. Fatty acids were quantified using heptadecanoic acid (C17:0) as internal standard. The highest lipid recovery (27.0 to 41.8% of total lipids) was obtained from the liver fraction. Palmitic acid (C16:0), oleic acid (18:1 n9), docosahexaenoic acid (22:6 n3), eicosapentaenoic acid (20:5 n3) and palmitoleic acid (16:1) were the main constituents. Protein levels in viscera without livers (V-L) were higher than those in the liver. The extraction of marine fish oil and the production of fish offal meal from waste from fish factories would contribute to the sustainability of the regional industry, because it would also decrease the volume of waste, with benefits to the environment. (Author)

Dieta de Hatcheria macraei (Girard, 1855 (Teleostei, Siluriformes, Trichomycteridae en el río Chubut, Argentina Diet of Hatcheria macraei (Girard, 1855 (Teleostei, Siluriforms, Trichomycteridae in the Chubut River, Argentina

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Ricardo A Ferriz

2012-03-01

Full Text Available Se realizó un estudio sobre la dieta de Hatcheria macraei capturados en el río Chubut, Bajada del Cóndor (43°31'21,12''S, 69°06'22,1''W, en abril 2000. El régimen alimentario de este tricomictérido correspondió al tipo carnívoro bentófago y las presas dominantes, tanto en juveniles como en adultos, fueron larvas de chironómidos, larvas de tricópteros y cladóceros. Los ejemplares adultos presentaron una mayor diversidad en la dieta que los juveniles.A study of the diet of Hatcheria macraei caught in Chubut River, Bajada del Cóndor (43°31'21,12''S; 69°06'22,1''W was performed in April 2000. The feeding regime of this Trichomycteridae agreed with the carnivorous bentophagous type, and the dominant preys of both adults and juveniles were chironomid larvae, tricopter larvae, and cladocerans. The adult specimens exhibited a more diverse diet than the juveniles.

Peopling of Northern Argentinean Patagonia during Late Holocene: paleoenvironments and social imperatives

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María Teresa BOSCHÍN

2012-03-01

Full Text Available In this paper, the role of central plateaus –dated at ca. 3500 AP– in the peopling of the southern end of America that started at around ca. 13000 AP, is discussed. A revision and updating of the archaeological and paleoclimatic evidences and their absolute chronologies were made. To Mid Holocene, the space that we defined as the periphery of central plateaus –Atlantic coast, Colorado, Limay and Chubut rivers– was conformed. During Late Holocene, the inland sites were characterized by a progresively increase in the density of archaeological remains, with dense occupations towards upper levels or the final settlement stage on the Plateaus. An inland Norpatagonia peopling model is proposed, based on which of the peripheral population loci could provoke exploratory and migratory movements, and paleoenvironmental and social explanations are considered.

Variabilidad morfométrica dental en muestras arqueológicas tardías del sudeste de la región pampeana y noreste de Patagonia

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Bernal, Valeria

2003-01-01

Full Text Available Recientemente, se ha postulado la ocurrencia de un proceso de expansión demográfico y geográfico de las poblaciones del norte de Patagonia durante el Holoceno tardío, con posterioridad a la denominada Anomalía Climática Medieval (ca. 800 - 1350 AD. En el marco del proyecto "La Dinámica Evolutiva de Poblaciones y Metapoblaciones Humanas en las Regiones Pampeana y Patagónica (33°- 52° Lat. Sur durante el Holoceno Tardío" (Subsidio de Inicio de Carrera Fundación Antorchas Nº 14116-111 se están desarrollando estudios orientados a analizar la variación morfológica craneal y postcraneal de las poblaciones humanas de ambas regiones, con el fin de discutir la dinámica poblacional durante el Holoceno tardío. En este contexto, el objetivo del presente trabajo es analizar la variabilidad morfométrica dental de muestras diacrónicas procedentes del SE de la Región Pampeana y NE de Patagonia (v.g. valles de los ríos Chubut y Negro, litoral atlántico sudbonaerense. Las variables consideradas incluyen diámetros mesiodistales y bucolinguales sobre la corona dental y el margen cervical, medidos sobre piezas dentales permanentes. Los resultados obtenidos mediante el empleo de test estadísticos uni y multivariados, serán discutidos con relación al resto de la evidencia morfológica actualmente disponible para ambas regiones.

Marine reptiles from the Late Cretaceous of northern Patagonia

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Gasparini, Z.; Casadio, S.; Fernández, M.; Salgado, L.

2001-04-01

During the Campanian-Maastrichtian, Patagonia was flooded by the Atlantic and reduced to an archipelago. Several localities of northern Patagonia have yielded marine reptiles. Analysis of several assemblages suggests that the diversity and abundance of pelagic marine reptiles in northern Patagonia was higher by the end of the Cretaceous than previously thought. Several plesiosaurids, including Aristonectes parvidens and the polycotylid Sulcusuchus, and the first remains of mosasaurinae have been found. The Cretaceous marine reptile record from South America is scanty. Nevertheless, materials described here suggest that Tethyan and Weddelian forms converged in northern Patagonia, as seen with invertebrates.

Paleomagnetism of Jurassic and Cretaceous rocks in central Patagonia: a key to constrain the timing of rotations during the breakup of southwestern Gondwana?

Science.gov (United States)

Geuna, Silvana E.; Somoza, Rubén; Vizán, Haroldo; Figari, Eduardo G.; Rinaldi, Carlos A.

2000-08-01

A paleomagnetic study in Jurassic and Cretaceous rocks from the Cañadón Asfalto basin, central Patagonia, indicates the occurrence of about 25-30° clockwise rotation in Upper Jurassic-lowermost Cretaceous rocks, whereas the overlying mid-Cretaceous rocks do not show evidence of rotation. This constrains the tectonic rotation to be related to a major regional unconformity in Patagonia, which in turn seems to be close in time with the early opening of the South Atlantic Ocean. The sense and probably the timing of this rotation are similar to those of other paleomagnetically detected rotations in different areas of southwestern Gondwana, suggesting a possible relationship between these and major tectonic processes related with fragmentation of the supercontinent. On the other hand, the mid-Cretaceous rocks in the region yield a paleopole located at Lat. 87° South, Long. 159° East, A95=3.8°. This pole position is consistent with coeval high-quality paleopoles of other plates when transferred to South American coordinates, implying it is an accurate determination of the Aptian (circa 116 Ma) geomagnetic field in South America.

La identidad en la encrucijada: la comunidad galesa del Chubut y las conmemoraciones del Centenario y Bicentenario de la Revolución de Mayo

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Geraldine Lublin

2013-12-01

Full Text Available El presente artículo se propone rastrear a grandes rasgos la relación ―especial‖ entre el estado nacional argentino y, a partir de 1958, la provincia de Chubut por una parte y los colonos galeses que se establecieron en Chubut desde 1865 y sus descendientes por otra, a través del análisis de la posición de la colectividad galesa del Chubut en dos momentos históricos destacados: el Centenario y el Bicentenario de la Revolución de Mayo (1810. Al corresponderse el perfil de los galeses con la idea de poblaciones "civilizadas" que las autoridades pretendían impulsar en desmedro de los legítimos pobladores originales, estas políticas dieron lugar a una fuerte identificación histórica de la Provincia de Chubut con la llamada "gesta galesa". Se generó asimismo una peculiar dinámica triangular de las relaciones estatales, cuya evolución a través del tiempo ha desembocado en la actual promoción de la identidad chubutense como el resultado de la fusión de las culturas de los tehuelches originarios y los colonos galeses.

Patagonia: tocando las fibras internas

OpenAIRE

Velasco Tafur, Ximena; Borrero Caldas, Silvio

2013-01-01

El presente caso, está enfocado en Patagonia, una compañía que desde sus inicios ha desarrollado una forma poco convencional en su estilo de hacer negocios. La gerencia de Patagonia considera que muchos errores administrativos obedecen a que las empresas formulan las mismas soluciones para todos los problemas que enfrentan. Además, desde la revolución industrial, tales soluciones han privilegiado las ganancias económicas sobre la sostenibilidad ambiental, y el planeta está pasando factura por...

Actividad antimicrobiana de bacterias ácido lácticas aisladas de invertebrados marinos de la costa del Chubut (Patagonia – Argentina

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Parada Romina

2017-11-01

Full Text Available Se estudió la actividad antagonista de cepas de bacterias ácido lácticas (BAL aisladas de invertebrados marinos de la costa del Chubut. Dentro de los 92 aislamientos, 22 exhibieron actividad, de las cuales 3 cepas se clasificaron como Lactobacillus y 19 como Enterococcus. En todos los casos, después de la neutralización con NaOH y tratamiento térmico, la actividad inhibitoria del sobrenadante libre de células de las cepas estudiadas permaneció activa. El tratamiento con lisozima y catalasa no afectó la actividad antimicrobiana; sin embargo la actividad enzimática de la tripsina abolió la acción inhibitoria de los sobrenadantes, confirmando la naturaleza proteica de los compuestos activos. Las actividades contra Listeria inocua ATCC 33090 logradas por cepas de Enterococcus variaron entre 640 y 163.840 unidades arbitrarias/mililitro (AU/ml, mientras que las cepas de Lactobacillus exhibieron actividades entre 20 y 40 AU/ml. Las cepas E. mundtii 278Pe, E. hirae 463Me y E. hirae 471Me exhibieron las actividades inhibitorias más altas contra un amplio espectro de bacterias patógenas y/o contaminantes de alimentos. A pesar de la amplia información disponible sobre estos microorganismos, existen pocos estudios de BAL aisladas a partir de invertebrados de origen marino. Los resultados obtenidos en este estudio sugieren que esta fuente puede contribuir al hallazgo de nuevas bacteriocinas con potencial uso en la industria alimentaria.

Variation in the proximate composition and fatty acid profile recovered from Argentine hake (Merluccius hubbsi waste from Patagonia

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Cretton, M.

2016-03-01

Full Text Available The fish processing operations in Patagonia produce large amounts of waste. The main fishery resource in Argentina is the Argentine hake (Merluccius hubbsi. The ports of the province of Chubut (the most important of which are Puerto Madryn, Rawson and Comodoro Rivadavia, together with Caleta Paula Port (province of Santa Cruz, in the Argentine Patagonia, capture more than 82,000 tons of hake annualy, 80% of which are of M. hubbsi, which is mostly converted into fillets. From this capture, about 2,296 tons of liver would be available for the extraction of oil. To promote the recovery and industrial use of fish oil, in the present study, we determined the variation in the proximate composition and fatty acid profile of Argentine hake waste from the ports mentioned above at different catch times. Proximate composition was determined according of the Official Methods of Analysis (AOAC. Fatty acid profile was analyzed by gas chromatography of the fatty acid methyl esters (FAMEs. A standard mixture of FAMEs was run under identical conditions to identify the compounds on the basis of their retention times. Fatty acids were quantified using heptadecanoic acid (C17:0 as internal standard. The highest lipid recovery (27.0 to 41.8% of total lipids was obtained from the liver fraction. Palmitic acid (C16:0, oleic acid (18:1 n9, docosahexaenoic acid (22:6 n3, eicosapentaenoic acid (20:5 n3 and palmitoleic acid (16:1 were the main constituents. Protein levels in viscera without livers (V-L were higher than those in the liver. The extraction of marine fish oil and the production of fish offal meal from waste from fish factories would contribute to the sustainability of the regional industry, because it would also decrease the volume of waste, with benefits to the environment.El procesamiento de pescados en Patagonia produce gran cantidad de residuos. El recurso de pesca más importante en la Argentina es la merluza argentina (Merluccius hubbsi. En Patagonia

Evaluation of the Cerro Solo nuclear ore, province of Chubut. The Cerro Solo project within the frame of uranium exploration in Argentina. Pt. 1

International Nuclear Information System (INIS)

Solis, R.J.; Navarra, P.R.; Benitez, A.F.; Gallucci, A.R.

1993-01-01

The Cerro Solo ore deposit was selected by the CNEA to invest in an assessment project because of their promising grade and amount of known and potential resources, significant to Argentina's uranium requirements. The deposit, which is located in the central region of the Chubut Province, belongs to the sandstone type and is hosted by the cretaceous Chubut Group. Technical studies carried out forecast an important growth of nuclear capacity to meet Argentina's energy requirements in the first two decades of of the the next century. To be in position to confront the challenge presented by increasing uranium resources to fuel the nuclear powers plants it is very important, as a first step, to improve the geological knowledge of uranium favorability in the country. The preliminary results of the Cerro Solo project indicate that the eastern slope of the Pichinan hills is a promising area for development of uranium resources, increasing the favorability of the San Jorge Basin in order to allow contributing to meet future uranium requirements. The Cerro Solo Project was planned in a sequential manner, as a multidisciplinary effort which includes studies on: geologic setting of mineralization, resource estimates, costs of mining and milling methods, economic analysis and environmental impact research. Among the mining methods, studies include the alternative of the in-situ leaching technology, which is becoming a low producing cost interesting possibility. (Author)

The Maritime Cultural Landscape of Northern Patagonia

Science.gov (United States)

Lira, Nicolás

2017-12-01

This article is a contribution to the study of the indigenous navigation and its boats in the region of northern Patagonia. This article also aims to contribute to the understanding of indigenous navigation practices and technologies and their origins from prehistoric times to the mid-twentieth century. It presents and discusses the concept of Westerdahl's Maritime Cultural Landscape in relation to other landscape concepts. This model is applied to northern Patagonia in order to discuss if it is possible to speak of a true maritime culture in the region. For this purpose, archaeological, historical and ethnographic data are presented in an integrative and innovative methodology for the discipline. Finally, the Maritime Cultural Landscape model will allow the integration of aquatic and terrestrial landscapes as routes traveled by native inhabitants of northern Patagonia and southern Chile, and propose an important and diversified maritime, river and lake tradition.

Mineralogical data on angelaite, Cu2AgPbBiS4, from the Los Manantiales District, Chubut, Argentina

DEFF Research Database (Denmark)

Topa, D.; Paar, W.H.; Putz, H.

2010-01-01

Angelaite, ideally Cu2AgPbBiS4, occurs as a hypogene mineral in polymetallic ores at the Ángela groups of veins in the mining district of Los Manantiales, in the province of Chubut, Argentina. The new mineral species is predominantly associated with pyrite, sphalerite, chalcopyrite, hematite...

Plan de comercialización Heliraid Patagonia

OpenAIRE

Mella, Natalia

2012-01-01

La Patagonia Argentina Austral, es considerada un icono a nivel mundial, reúne un conjunto de provincias y aspectos naturales únicos en el mundo1. La Cordillera de los Antes, sus paisajes, su geografía, y su historia. Muchos han sido los aventureros que dieron su vida por explorar y conocer esta zona. Y no todos vivieron para contarlo. Tradicionalmente, la Patagonia se caracterizaba por un escaso desarrollo comercial a raíz de los altos costos y su inaccesibilidad geográfica. Hoy, el desarrol...

Nocturnal feeding under artificial light conditions by Brown-hooded Gull (Larus maculipennis) in Puerto Madryn harbour (Chubut Province, Argentina)

NARCIS (Netherlands)

Leopold, M.F.; Philippart, C.J.M.; Yorio, P.

2010-01-01

This paper describes nocturnal, marine feeding behaviour in the Brown-hooded Gull (Larus maculipennis) in November 2009. The gulls assembled at night at the end of a long pier, running 800 m offshore into the Golfo Nuevo, at Puerto Madryn, Chubut Province, Argentina. Powerful lights predictably

Análisis de sistema de conversores fluido-dinámicos de energía renovable para la Patagonia Austral de Argentina

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Carlos Victor Manuel Labriola

2014-06-01

Full Text Available El potencial de energía en mares y océanos se puede clasificar de distintas formas, por ejemplo: * La energía de las mareas ó Mareomotriz * La energía de las corrientes marinas * La energía de las olas ó Undimotriz * La energía térmica oceánica (OTEC. De estas formas de energía oceánica, tres son posibles en la zona Atlántica de nuestra Patagonia Austral, la Mareomotriz, la Undimotriz y la de corrientes marinas. La Energía Mareomotriz se da desde Viedma hasta Tierra del Fuego con amplitudes de mareas de 4m hasta 20m, la Energía de las Olas se da en la costa de Chubut y Santa Cruz con potenciales de 10 a 30kW/m lineal de frente de ola y el aprovechamiento de las corrientes marinas se puede dar en lugares puntuales como ser la desembocadura del río Deseado o la de Río Gallegos. Para estas Fuentes de Energía se está realizando un banco de pruebas de modelos conversores de las mismas a Energía Eléctrica, en la Unidad Académica Caleta Olivia (UACO de la Universidad Nacional de la Patagonia Austral (UNPA. Este banco dispondrá de dos canales de ensayos hidrodinámicos uno para energía de las corrientes marinas y otro para las olas. El primero dispondrá de una bomba de circulación con velocidad de fluido variable entre 0 y 4m/s. El banco para olas tendrá un sistema de batido del agua para producir ondas de amplitud y período variable. Además se están dimensionando dos modelos de conversores de energía oceánica. Uno es una turbina, tipo eólica sumergida y el otro modelo es de tubo electromecánico oscilante como conversor energético de las olas.

Genomic insights into the origin and diversification of late maritime hunter-gatherers from the Chilean Patagonia.

Science.gov (United States)

de la Fuente, Constanza; Ávila-Arcos, María C; Galimany, Jacqueline; Carpenter, Meredith L; Homburger, Julian R; Blanco, Alejandro; Contreras, Paloma; Cruz Dávalos, Diana; Reyes, Omar; San Roman, Manuel; Moreno-Estrada, Andrés; Campos, Paula F; Eng, Celeste; Huntsman, Scott; Burchard, Esteban G; Malaspinas, Anna-Sapfo; Bustamante, Carlos D; Willerslev, Eske; Llop, Elena; Verdugo, Ricardo A; Moraga, Mauricio

2018-04-24

Patagonia was the last region of the Americas reached by humans who entered the continent from Siberia ∼15,000-20,000 y ago. Despite recent genomic approaches to reconstruct the continental evolutionary history, regional characterization of ancient and modern genomes remains understudied. Exploring the genomic diversity within Patagonia is not just a valuable strategy to gain a better understanding of the history and diversification of human populations in the southernmost tip of the Americas, but it would also improve the representation of Native American diversity in global databases of human variation. Here, we present genome data from four modern populations from Central Southern Chile and Patagonia ( n = 61) and four ancient maritime individuals from Patagonia (∼1,000 y old). Both the modern and ancient individuals studied in this work have a greater genetic affinity with other modern Native Americans than to any non-American population, showing within South America a clear structure between major geographical regions. Native Patagonian Kawéskar and Yámana showed the highest genetic affinity with the ancient individuals, indicating genetic continuity in the region during the past 1,000 y before present, together with an important agreement between the ethnic affiliation and historical distribution of both groups. Lastly, the ancient maritime individuals were genetically equidistant to a ∼200-y-old terrestrial hunter-gatherer from Tierra del Fuego, which supports a model with an initial separation of a common ancestral group to both maritime populations from a terrestrial population, with a later diversification of the maritime groups.

Caracterización de un proceso de biorremediación de hidrocarburos en deficiencia de nitrógeno en un suelo de la Patagonia Argentina

OpenAIRE

Acuña, Adrián Javier; Pucci Ceima, Oscar Héctor; Pucci Bissetta, Graciela Natalia

2008-01-01

La zona central de la Patagonia, Argentina, se encuentra sometida a explotación petrolera y sus suelos se caracterizan por ser deficientes en nitrógeno. Esto causaría un efecto negativo en los procesos de atenuación natural que se desarrollan en los suelos contaminados con hidrocarburos. El objeto de este estudio fue determinar cual es el efecto de la deficiencia de nitrógeno sobre la biodegradación de los hidrocarburos en un suelo de la Patagonia, Argentina. Se trabajó con tres micr...

Human effects in Holocene fire dynamics of Central Western Patagonia (~44° S, Chile

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César Méndez

2016-08-01

Full Text Available The forest-steppe ecotone of the eastern slope of the Andes in Central Western Patagonia (43°40'-49°15' S, Chile, South America provides a unique area for assessing long and short term dynamics between humans and past environments. Central Western Patagonian was a demographically marginal zone inhabited intermittently and with low intensity by hunter-gatherers during the Holocene. This paper adopts a novel approach in order to assess the relationship between trends in the archaeological, pollen and charcoal records. The recognition of temporal and spatial scales in both archaeology and paleoecology is crucial for defining roles in paleofire records. The main goal of the paper is to assess the role of climate and human beings as potential ignitors of wildfires by acknowledging the scales in which they operate and the different roles either one played in paleofire trends. We investigated a case study in the Cisnes River Valley where the frequencies and magnitudes of fire episodes – reconstructed from macro-charcoal particles from the Lake Shaman intermoraine sequence – can be attributed to human action, while acknowledging the driving role of climate over broader time scales. The Lake Shaman charcoal record spanning the last 19000 cal years is compared to the archaeological record starting at 11500 cal years BP. After comparing paleofires, reconstructed from the charcoal record, with peaks and troughs in the radiocarbon record and archaeological evidence at local and site scales, we argue that this approach provides insights for assessing the timing and magnitude of human effects on the environment. We examine collation and correlation scenarios for comparative trends between the archaeological, pollen and charcoal records. The correlation of occupational events at the El Chueco 1 archaeological site and other sites along the Cisnes River Valley with the results obtained at Lake Shaman is suggestive of a combination of human agency and

Patagonia: nature and territories

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Alejandro Fabián Schweitzer

2014-12-01

This paper analyzes the place occupied by Patagonia in today’s fin de siècle scenario of commodities, hegemony crisis and multi-polar world emergence concurring with the convergence of consumerist guidelines, all of which would apparently lead to an in-depth socio-ecological crisis as well as to an accelerated dispute over nature and territory sense.

Gravimetric model of the Gastre trough, province of Chubut, Argentina; Modelo gravimetrico en la fosa de Gastre, provincia de Chubut, Argentina

Energy Technology Data Exchange (ETDEWEB)

Lince Klinger, F.; Nacif, S.; Martinez, M. P.; Gimenez, M. E.; Ruiz, F.; Alvarez, O.

2011-07-01

A gravimetric study of the Gastre trough in the Province of Chubut, to the southwest of the Canadon Asfalto basin, has allowed us to determine the geometry of its crystalline basement. Using filtering techniques we were able to map residual Bouguer anomalies, which show the heterogeneities situated within the upper crust, some of which are linked to recognised geological structures. The gravimetric minima in the residual Bouguer anomaly map are associated with graben-type basins, flanked by positive gravity values associated with alignments identified on the surface and with the overall topographic relief of the Gastre trough. After suitable treatment of the density values of the outcrops and seismic data we were able to construct a 2D density model, perpendicular to the trough, which indicated a depth of 3600 m. The importance of this study lies in the fact that it has been possible to arrive at a gravimetric characterization of the Gastre trough in the Canadon Asfalto basin sector, a potentially hydrocarbon-bearing area hitherto lacking in reliable data concerning its subsoil. (Author)

Uplift of quaternary shorelines in eastern Patagonia: Darwin revisited

Science.gov (United States)

Pedoja, Kevin; Regard, Vincent; Husson, Laurent; Martinod, Joseph; Guillaume, Benjamin; Fucks, Enrique; Iglesias, Maximiliano; Weill, Pierre

2011-04-01

During his journey on the Beagle, Darwin observed the uniformity in the elevation of coastal Eastern Patagonia along more than 2000 km. More than one century later, the sequences of Quaternary shorelines of eastern Patagonia have been described and their deposits dated but not yet interpreted in terms of geodynamics. Consequently, we i) mapped the repartition of the Quaternary coastal sequences in Argentinean Patagonia, ii) secured accurate altitudes of shoreline angles associated with erosional morphologies (i.e. marine terraces and notches), iii) took into account previous chrono-stratigraphical interpretations in order to calculate mean uplift rates since ~ 440 ka (MIS 11) and proposed age ranges for the higher and older features (up to ~ 180 m), and iv) focused on the Last Interglacial Maximum terrace (MIS 5e) as the best constrained marine terrace (in terms of age and altitude) in order to use it as a tectonic benchmark to quantify uplift rates along the entire passive margin of Eastern South America. Our results show that the eastern Patagonia uplift is constant through time and twice the uplift of the rest of the South American margin. We suggest that the enhanced uplift along the eastern Patagonian coast that interested Darwin during his journey around South America on the Beagle could originate from the subduction of the Chile ridge and the associated dynamic uplift.

Oceanography of the Chilean Patagonia

Science.gov (United States)

Pantoja, Silvio; Luis Iriarte, José; Daneri, Giovanni

2011-03-01

Chilean Patagonia is one of the most extended fjord regions in the world that covers nearly 240,000 km 2 with an extremely complex coastline and topography in one of the least densely populated areas of the country (1-8 inhabitants every 10 km 2). In recent years, the area has been undergoing somewhat intense pressure since several commercial projects in hydroelectricity, tourism, and commercial salmon and mytilid cultures have been developed, or are in progress. Concomitantly, several large research programs have been devised to study the physical, chemical, and biological environment of Patagonia, such as the CIMAR FIORDO, and recently COPAS Sur-Austral based at Universidad de Concepcion, that attempts to close the bridge between oceanographic knowledge and its use by society. In this introductory article we summarize the collection of papers comprising this Special Issue of Continental Shelf Research. These papers deal with aspects of regional oceanography and geology, inorganic and organic geochemistry, ecology of pelagic and benthic organisms, and past changes in productivity.

Patagonia, Land of Nomads: A Glance at a Territory Shaped by Displacement

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Pablo Chiuminatto

2016-05-01

Full Text Available By the end of the nineteenth century, as global voyages became popular, and transcontinental empires settled, remote corners of the third world such as Patagonia began to be explored and became the subject of European travel literatures. The opening of this region to the global scenario produced profound transformations in its territorial conformation, poetic imaginary, and local culture. As Patagonia became a land of travellers, local nomads which had inhabited this land for centuries became extinguished. The historical context of this re-shaping is conceptualised in literary theory through notions such as nomadism, elaborated by Gilles Deleuze and its aesthetical counterpart, geo-poetics, by Kenneth White. The travel literature about Patagonia, such as that produced by Charles Darwin, Lady Florence Dixie, and Bruce Chatwin, depicts the difficulties these travellers faced in trying to endow their writings of adequate descriptions and images. Instead, they recurred to images from their homeland, and thus created an imaginary of Patagonia through displacement: their own, and that of images brought by themselves to this land. When Chilean poets like Gabriela Mistral and Pablo Neruda begun to write about Patagonia, they found it already populated by strange images, shaped indeed, by nomads, travellers and dis-located identities.

Ceratopetalum (Cunoniaceae) fruits of Australasian affinity from the early Eocene Laguna del Hunco flora, Patagonia, Argentina.

Science.gov (United States)

Gandolfo, María A; Hermsen, Elizabeth J

2017-03-01

Radially symmetrical, five-winged fossil fruits from the highly diverse early Eocene Laguna del Hunco flora of Chubut Province, Patagonia, Argentina, are named, described and illustrated. The main goals are to assess the affinities of the fossils and to place them in an evolutionary, palaeoecological and biogeographic context. Specimens of fossil fruits were collected from the Tufolitas Laguna del Hunco. They were prepared, photographed and compared with similar extant and fossil fruits using published literature. Their structure was also evaluated by comparing them with that of modern Ceratopetalum (Cunoniaceae) fruits through examination of herbarium specimens. The Laguna del Hunco fossil fruits share the diagnostic features that characterize modern and fossil Ceratopetalum (symmetry, number of fruit wings, presence of a conspicuous floral nectary and overall venation pattern). The pattern of the minor wing (sepal) veins observed in the Patagonian fossil fruits is different from that of modern and previously described fossil Ceratopetalum fruits; therefore, a new fossil species is recognized. An apomorphy (absence of petals) suggests that the fossils belong within crown-group Ceratopetalum . The Patagonian fossil fruits are the oldest known record for Ceratopetalum . Because the affinities, provenance and age of the fossils are so well established, this new Ceratopetalum fossil species is an excellent candidate for use as a calibration point in divergence dating studies of the family Cunoniaceae. It represents the only record of Ceratopetalum outside Australasia, and further corroborates the biogeographic connection between the Laguna del Hunco flora and ancient and modern floras of the Australasian region. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company.

HOTELES DE TRELEW (CHUBUT, ARGENTINA) HACIA EL DESARROLLO SUSTENTABLE DE LA ACTIVIDAD CON RESPONSABILIDAD SOCIAL

OpenAIRE

Ana M. Gómez; María Elena Sendín

2008-01-01

El trabajo se enmarca en el Proyecto de Investigación “Hotelería Sustentable en la Ciudad de Trelew, Provincia del Chubut, República Argentina” cuyo objetivo general es diseñar un sistema de Administración para la hotelería de Trelew, que viabilice su gestión en el marco del desarrollo sustentable de la actividad hotelera. Como hipótesis de trabajo se supuso que la hotelería estaría en condiciones de tener una gestión sustentable cuando demostrara poseer una cultura empresarial dirigida al...

Reptiles of Chubut province, Argentina: richness, diversity, conservation status and geographic distribution maps

Science.gov (United States)

Minoli, Ignacio; Morando, Mariana; Avila, Luciano Javier

2015-01-01

Abstract An accurate estimation of species and population geographic ranges is essential for species-focused studies and conservation and management plans. Knowledge of the geographic distributions of reptiles from Patagonian Argentina is in general limited and dispersed over manuscripts from a wide variety of topics. We completed an extensive review of reptile species of central Patagonia (Argentina) based on information from a wide variety of sources. We compiled and checked geographic distribution records from published literature and museum records, including extensive new data from the LJAMM-CNP (CENPAT-CONICET) herpetological collection. Our results show that there are 52 taxa recorded for this region and the highest species richness was seen in the families Liolaemidae and Dipsadidae with 31 and 10 species, respectively. The Patagónica was the phytogeographic province most diverse in species and Phymaturus was the genus of conservation concern most strongly associated with it. We present a detailed species list with geographical information, richness species, diversity analyses with comparisons across phytogeographical provinces, conservation status, taxonomic comments and distribution maps for all of these taxa. PMID:25931966

Occurrence of Hirudinea species in a post urban reach of a Patagonian mountain stream

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M. Laura Miserendino

2014-09-01

Full Text Available Temporal (May 2005 to February 2006 and habitat distribution (pools and riffles of Hirudinea species was analyzed at a post urban reach from Esquel stream (Chubut province, Patagonia, Argentina. Site was located 5.7 km downstream a Waste Treatment Plant. Mean values of nutrients: ammonia, nitrates and soluble reactive phosphate, as well water conductivity, turbidity and total suspended solids indicated physical and organic pollution. Leeches assemblage was composed by the glossiphonids: Helobdella scutifera Blanchard, 1900, H. michaelseni (Blanchard, 1900, H. simplex (Moore, 1911, Helobdella sp., H. hyalina Ringuelet, 1942, H. obscura Ringuelet, 1942 and the semiscolecid Patagoniobdella variabilis (Blanchard, 1900. From these H. hyalina and H. obscura are new records for Chubut province. Helobdella hyalina (810 ind.m-2 and H. simplex (465 ind. m-2 clearly dominated the assemblage at the reach. Only H. simplex displayed a spatial preference being significantly more abundant in pools than in riffle habitats (p<0.001. Species recruitment occurred mostly at September, December and March when juveniles were very abundant. Although several species of Helobdella were able to live in the disturbed section of the stream, only H. simplex and H. hyalina sustained large populations at the site and can be considered as tolerant to organic enrichment. This information is valuable to future studies on stream condition assessment in mountainous areas in Patagonia, and in other areas in which these species are present.

Inherited discontinuities and fault kinematics of a multiphase, non-colinear extensional setting: Subsurface observations from the South Flank of the Golfo San Jorge basin, Patagonia

Science.gov (United States)

Paredes, José Matildo; Aguiar, Mariana; Ansa, Andrés; Giordano, Sergio; Ledesma, Mario; Tejada, Silvia

2018-01-01

We use three-dimensional (3D) seismic reflection data to analyze the structural style, fault kinematics and growth fault mechanisms of non-colinear normal fault systems in the South Flank of the Golfo San Jorge basin, central Patagonia. Pre-existing structural fabrics in the basement of the South Flank show NW-SE and NE-SW oriented faults. They control the location and geometry of wedge-shaped half grabens from the "main synrift phase" infilled with Middle Jurassic volcanic-volcaniclastic rocks and lacustrine units of Late Jurassic to Early Cretaceous age. The NE-striking, basement-involved normal faults resulted in the rapid establishment of fault lenght, followed by gradual increasing in displacement, and minor reactivation during subsequent extensional phases; NW-striking normal faults are characterized by fault segments that propagated laterally during the "main rifting phase", being subsequently reactivated during succesive extensional phases. The Aptian-Campanian Chubut Group is a continental succession up to 4 km thick associated to the "second rifting stage", characterized by propagation and linkage of W-E to WNW-ESE fault segments that increase their lenght and displacement in several extensional phases, recognized by detailed measurement of current throw distribution of selected seismic horizons along fault surfaces. Strain is distributed in an array of sub-parallel normal faults oriented normal to the extension direction. A Late Cretaceous-Paleogene (pre-late Eocene) extensional event is characterized by high-angle, NNW-SSE to NNE-SSW grabens coeval with intraplate alkali basaltic volcanism, evidencing clockwise rotation of the stress field following a ∼W-E extension direction. We demonstrate differences in growth fault mechanisms of non-colinear fault populations, and highlight the importance of follow a systematic approach to the analysis of fault geometry and throw distribution in a fault network, in order to understand temporal-spatial variations

Estado actual del conocimiento de la familia Ceratopogonidae en la Patagonia (Diptera: Nematocera Current knowledge of the family Ceratopogonidae in Patagonia (Diptera: Nematocera

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Gustavo R. Spinelli

2009-06-01

Full Text Available Ceratopogonidae incluye pequeños dípteros nematoceros que crían en hábitats acuáticos o semiacuáticos. Hasta los '80, el conocimiento de su taxonomía en la Patagonia se hallaba limitado a la contribución de los comienzos de los '30 de Ingram y Macfie, sobre la base de material capturado en 1926-27, en el área del Parque Nacional Nahuel Huapi y zonas vecinas de Chile. En los últimos 25 años, se pusieron en marcha diferentes proyectos, resultando la descripción o registro de numerosos taxones para la región. Si se contabilizan los datos publicados, 102 especies habitan en la Patagonia, de las cuales 86 (84,31% son endémicas para la región. Este alto porcentaje es evidente en los bosques de Nothofagus, con 71 especies endémicas de este bioma, nueve lo son de la estepa y seis presentan registros en bosque y estepa. Datos aún no publicados concuerdan con este esquema. Diecinueve géneros están representados en la Patagonia, diez de ellos con amplia distribución, tres de distribución transantártica y seis son endémicos para el área. Para la misma, se hallan publicadas las revisiones de Forcipomyia, Atrichopogon, Borkenthelea, Macrurohelea y Paradasyhelea; se han finalizado y aún no publicado aquellas de Dasyhelea y Palpomyia, está muy avanzada la de Stilobezzia y se prevé comenzar con las de Austrohelea, Austrosphaeromias, Physohelea y Bezzia. Se calcula que estos datos no divulgados contienen al menos 55 especies todavía no descriptas. Con respecto a los aspectos biogeográficos se pueden destacar estudios que tienden a establecer relaciones entre las áreas reconocidas en esquemas biogeográficos propuestos para la región andina.Ceratopogonidae includes small nematoceran Diptera which breed in aquatic and semiaquatic habitats. Until the 80´s its taxonomic knowledge in Patagonia was limited to the early 30´s contribution of Ingram and Macfie, from material collected in 1926-27 in the area of the Nahuel Huapi National

The impact of Chilean migration on employment in Patagonia.

Science.gov (United States)

Cariola Sanz, L

1989-06-01

This paper discusses the employment situation of Chilean migrant workers, their impact on labor markets in Patagonia, Argentina, and the government's past and projected responses to this phenomenon. In 1980, Chilean inhabitants of patagonia comprised 11% of the area's population. Chilean migration to patagonia was closely linked to economic activities that began to flourish in the 20th century, such as livestock raising, fruit and vegetable cultivation, and mining for coal and petroleum. No Chilean migrants work in a wide range of sectors. In Patagonia's southern provinces availability and ability to withstand rigorous climate conditions are the main factors which account for the prevalence of Chilean manpower. Chilean migrants do not in general displace local manpower. Legislation and the permeability of the border ensure that most workers enter the country as tourists. Clandestine migration is not an issue. Illegal migrants have provoked negative reactions for several reasons: 1) they comprise a marginal population without formal citizenship; 2) being employed as clandestine workers, they pay no social security, nor do their employers; 3) being illegal, they are obliged to accept lower wages and inferior working conditions which creates unfair competition within labor markets; and 4) as a result of these conditions, xenophobic and endophobic attitudes in relations with Argentine nationalists are reinforced. The government has attempted to solve these problems through various measures. Beginning in 1934, most foreigners entered Argentina with a tourist visa, becoming illegal when they stayed beyond authorized limits. Several measures over the years provided amnesty to illegal migrants. Currently, the law promotes immigration, monitors the admission of foreigners to the country and stipulates their rights and obligations. The law lists 115 articles on immigration promotion and on regulation of the movements of foreigners. Because of the present economic crisis in

Estado del conocimiento taxonómico de la fauna de Chironomidae (Diptera: Nematocera de la Patagonia Current state of the taxonomic knowledge of the Chironomidae fauna (Diptera: Nematocera from Patagonia

Directory of Open Access Journals (Sweden)

Mariano Donato

2009-06-01

Full Text Available La familia Chironomidae (Diptera: Nematocera es uno de los grupos de insectos más ampliamente distribuidos y abundantes en cuerpos de agua dulce. Los representantes de esta familia pueden explotar áreas con amplios gradientes ambientales. La información que se presenta está basada en la recopilación de datos distribucionales bibliográficos, del estudio del material tipo de las especies de Chironomidae depositadas en el Natural History Museum (UK y del material de colección del Museo de La Plata (Argentina. En la Patagonia, se registran 9 subfamilias, la subfamilia monotípica Chilenomyiinae es endémica de esta área. Dentro de estas subfamilias, 53 de los 111 géneros conocidos para América del Sur están presentes en la Patagonia. Del total de géneros de la Patagonia, el 20 % es endémico y 7 de ellos muestran relaciones transantárticas. En la Patagonia, se registran 177 especies de Chironomidae, el 98% de éstas son endémicas, el 3 % son consideradas nomina dubia y el 17% requiere revisión ya que su ubicación sistemática es dudosa. Las descripciones originales de las especies patagónicas de Chironomidae están basadas principalmente sobre machos (n=58 y machos y hembras (n=43, ambas representan el 57% del total; el resto de las especies han sido descriptas con diferentes combinaciones de estadios del ciclo de desarrollo.The Chironomidae (Diptera: Nematocera family is one of the most widely distributed group of insects and often the most abundant in freshwater environments. Representatives of this family can exploit a wide range of environmental gradients. The information here presented is based on the compilation of distributional data obtained from bibliography, the study of the type material deposited in the Natural History Museum (UK and the collection material from Museo de La Plata (Argentina. Nine subfamilies are recorded from Patagonia, being the monotypic subfamily Chilenomyiinae endemic for the area. From the 111 known

Freshwater fishes of Patagonia: conservation and fisheries.

Science.gov (United States)

Cussac, V E; Habit, E; Ciancio, J; Battini, M A; Riva Rossi, C; Barriga, J P; Baigún, C; Crichigno, S

2016-07-01

The absence of much literature on the Patagonian fish fauna in comparison with that of the neotropics, has previously been blamed on its poor species diversity. Knowledge of the fishes of Patagonia, however, rose sharply at the beginning of the present century, allowing for an understanding of the complex biogeographical history that has led to the present diversity and distribution patterns. There are several new and potential threats to biodiversity and conservation of Patagonian fishes, such as the introduction of exotic species, damming, climate change and changes geared to safeguard economic interests, often acting synergistically. A great amount of new information is now available and the aim of the present review is to articulate this knowledge in a comprehensive way in order to aid in the development of tools to face the increasing challenges posed by environmental change and human activity. Knowledge about fishes of Patagonia has grown at the same time as human actions, and presence. © 2016 The Fisheries Society of the British Isles.

Biometric identification of capillariid eggs from archaeological sites in Patagonia.

Science.gov (United States)

Taglioretti, V; Fugassa, M H; Beltrame, M O; Sardella, N H

2014-06-01

Numerous eggs of capillariid nematodes have been found in coprolites from a wide range of hosts and in raptor pellets in archaeological samples from Patagonia. The structure and sculpture of the eggshell of these nematodes and their biometry are commonly used for identification. The aim of this study was to determine whether eggs of the genus Calodium with similar morphology, found in different archaeological samples from Patagonia, belong to the same species. For this purpose, capillariid eggs (N= 843) with thick walls and radial striations were studied by permutational multivariate analysis of variance (PERMANOVA). Eggs exhibiting similar shape and structure also showed similar biometry, regardless of the zoological origin of coprolites (P= 0.84), host diet (P= 0.19), character of the archaeological sites (P= 0.67) and chronology (P= 0.66). Thus, they were attributed to the same species. We suggest that an unidentified zoonotic species of the genus Calodium occurred in the digestive tract of a wide range of hosts in Patagonia during the Holocene and that both human and animal populations were exposed to this parasite during the Holocene in the study area.

A new burmagomphid dragonfly from the Eocene of Patagonia, Argentina

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Julián F. Petrulevičius

2017-11-01

Full Text Available A new burmagomphid anisopteran, Satelitala soberana gen. et sp. nov. is described from the lower Eocene of Laguna del Hunco, Patagonia, Argentina. The new genus is characterised by hindwing characters such as the subdiscoidal triangle not elongated; anal loop divided longitudinally; paranal cell divided longitudinally; five terminal cells between RP and MA; five terminal cells between MP and CuA; and obtuse angle between PsA and CuP+AA. Burmagomphid dragonflies were represented so far only by one specimen from the middle Cretaceous of Southeast Asia. This new record extends the distribution to Patagonia, to the Cenozoic, and also to paleolake deposits.

Programa provincial de lectura del Chubut

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Natalia Alejandra Alaniz

2014-10-01

Full Text Available En el marco del proyecto “Dispositivos pedagógicos en las dinámicas de lavida escolar en contexto de pobreza urbana” lo que se propuso investigar es la forma de implementación del Programa de Lectura de la provincia de Chubut. El mismo fue creado por Resolución Ministerial N° 1044/ 08, a partir de diversos trabajos que comenzaron en el año 2003 a través de la Ley de Educación 26. 026, y que posteriormente se incorporaron a nivel provincial mediante la Resolución N ° 174/12 para revalorizar las trayectorias escolares de cada niño/a. El programa consiste en poner el énfasis en el vínculo pedagógico mediante la adecuación de los espacios curriculares, de tal modo que se pueda lograr una articulación entre los diferentes niveles educativos, desde el nivel inicial al secundario. Articulando para ello recursos materiales y humanos que posibiliten el acompañamiento del proceso de enseñanza y aprendizaje de lectura.A partir de esto, el objetivo de este trabajo fue indagar cómo perciben los docentes de una escuela pública la implementación del Programa Provincial de Lectura, lo que implico utilizar metodologías y técnicas de investigación apropiadas para obtener las experiencias actuales en el territorio y en la cotidianidad de los propios actores escolares. Teniendo en consideración que el dispositivo pedagógico es una construcción histórica, que produce subjetividades, y por consiguiente formas de ver y entender el mundo.

Internal parasites of free-ranging guanacos from Patagonia.

Science.gov (United States)

Beldomenico, P M; Uhart, M; Bono, M F; Marull, C; Baldi, R; Peralta, J L

2003-12-01

In the winter of 2000, a greater than 80% reduction in the guanaco population located in Cabo Dos Bahi;as Wildlife Reserve, Chubut, Argentina, was evident due to massive mortality attributed to starvation. Twelve guanacos were necropsied and samples were analyzed at the Parasitology Laboratory of Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral. Fecal analysis revealed developmental stages of Nematodirus sp., Marshallagia sp., Trichuris sp. and Eimeria spp. Histopathological analysis showed the presence of Sarcocystis sp. in muscle and fascia cysts. Other parasites recovered included Dictyocaulus filaria, Trichuris tenuis and Moniezia expansa. Of these, D. filaria and M. expansa possibly reflect interactions with domestic sheep. This is the first time that T. tenuis has been reported in guanacos.

A new pentatomoid bug from the Ypresian of Patagonia, Argentina

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Julián F. Petrulevičius

2016-12-01

Full Text Available A new pentatomoid heteropteran, Chinchekoala qunita gen. et sp. nov. is described from the lower Eocene of Laguna del Hunco, Patagonia, Argentina. The new genus is mainly characterised by cephalic characters such as the mandibular plates surpassing the clypeus and touching each other in dorsal view; head wider than long; and remarkable characters related to the eyes, which are surrounded antero-laterally and posteriorly by the anteocular processes and the pronotum, as well as they extend medially more than usual in the Pentatomoidea. This is the first pentatomoid from the Ypresian of Patagonia and the second from the Eocene in the region, being the unique two fossil pentatomoids in Argentina.

Green marketing impact on a company’s success : studying the case of Patagonia

OpenAIRE

Ventura, Manuel Robles Machado Simões

2016-01-01

The increased demand for products with low environmental impact has increased the number of green marketing campaigns released during the last years. However, the impact of green marketing in companies’ performance is not clear. It mainly depends on the company’s characteristics and the perceived honesty of their green claims. Thus, the present study aimed to analyze the impact of green marketing in a particular company, Patagonia. Patagonia is recognized as a pioneer in corporate environment...

Valorización de la naturaleza y disputa por el territorio en la Provincia de Santa Cruz

OpenAIRE

Godoy, Pablo; Fasioli, Enzo; Valiente, Silvia; Schweitzer, Alejandro

2013-01-01

Desde los inicios de la colonización europea, la historia de la Patagonia es la trayectoria de la ocupación para la puesta en valor de la riqueza de sus bienes naturales en el suelo, subsuelo y en su extenso litoral marítimo. Asentados primero en la explotación del ovino, luego del petróleo, el gas y el carbón y recientemente de la pesca, la minería metalífera y el turismo internacional, los territorios de las actuales provincias de Santa Cruz, del Chubut y de Tierra del Fuego, al igual que s...

Airborne laser altimetry survey of Glaciar Tyndall, Patagonia

DEFF Research Database (Denmark)

Keller, K.; Casassa, G.; Rivera, A.

2007-01-01

The first airborne laser altimetry measurements of a glacier in South America are presented. Data were collected in November of 2001 over Glaciar Tyndall, Torres del Paine National Park, Chilean Patagonia, onboard a Twin Otter airplane of the Chilean Air Force. A laser scanner with a rotating...

Test strip at the Musters lake area, Chubut province (Argentina)

International Nuclear Information System (INIS)

Lopez, Luis E.

1998-01-01

A local test strip to determine both the system sensitivities and height attenuation coefficients was defined at the Musters Lake area, for its use in airborne spectrometric surveys in the South Patagonia region. The selected calibration range presents both low and uniform radioelement concentration. The mean spectrometer values obtained at ground level were 1.8 % K, 1.6 ppm eU and 7.3 ppm eTh while the variation coefficients were 7.5 %, 27.0 %, and 10.2 %, respectively. These values as well as range dimensions, moisture condition, easy access, easy navigation for aircraft, proximity to a fresh water body and with no flight restrictions are consistent with the international recommendations for setting up a test range. (author)

Test strip at the Musters Lake area, Chubut province (Argentina)

International Nuclear Information System (INIS)

Lopez, Luis E.

1998-01-01

A local test strip to determine both the system sensitivities and height attenuation coefficients was defined at the Musters Lake area, for its use in airborne spectrometric surveys in the South Patagonia region. The selected calibration range presents both low and uniform radioelement concentrations. The mean spectrometer values obtained at ground level were 1.8 % K, 1.6 ppm eU and 7.3 ppm eTh while the variation coefficients were 7.5 %, 27.0 %, and 10.2 %, respectively. These values as well as range dimensions, moisture condition, easy access, easy navigation for aircraft, proximity to a fresh water body and with no flight restrictions are consistent with the international recommendations for setting up a test range. (author)

Indigenous identity and textiles: an economic policy strategies in the province of Chubut La identidad indígena y sus textiles: estrategias de una política económica en la provincia de Chubut

Directory of Open Access Journals (Sweden)

Patricia María Méndez

2010-01-01

Full Text Available From the conception of the identity of individuals and of the groups as an elaboration, arises that the current indigenous identity employed by the state in the province of Chubut is functional to a policy which aims to prevent the emigration of the few people in rural areas of the province. It affirms that such a strategy is not new and that in the past other versions of this identity have also been useful to legitimate power projects. Through ethnographic and historical work, we explore some physical and social characteristics of rural areas of that province, some provincial regulations of government agencies, and certain attributes, preterits and present, of the indigenous identity employed by the state and of one of its symbols, Mapuche tissues. Laterally it refers in what way this identity is considered by some identified.A partir de la concepción de la identidad de las personas y de los grupos como una elaboración, se plantea que la actual identidad indígena empleada por el Estado en la provincia de Chubut resulta funcional a una política que pretende evitar la emigración de los escasos pobladores de las zonas rurales de la provincia. Se afirma que tal estrategia no es novedosa y que en el pasado otras versiones de esa identidad también han resultado útiles a los proyectos del poder legítimo. Mediante un trabajo etnográfico e histórico, se analizan algunas características físicas y sociales de la zona rural de esa provincia, algunas normativas de organismos gubernamentales provinciales, y ciertos atributos pretéritos y actuales de la identidad indígena empleada por el Estado y de uno de sus símbolos, los tejidos mapuches. Lateralmente se refiere de qué manera esa identidad es considerada por algunos identificados.

Quantifying mass balance processes on the Southern Patagonia Icefield

DEFF Research Database (Denmark)

Schaefer, M.; Machguth, Horst; Falvey, M.

2015-01-01

We present surface mass balance simulations of the Southern Patagonia Icefield (SPI) driven by downscaled reanalysis data. The simulations were evaluated and interpreted using geodetic mass balances, measured point balances and a complete velocity field of the icefield for spring 2004. The high m...

A tale of three hydros - post-privatisation in Patagonia

International Nuclear Information System (INIS)

Smith, H.F.

1994-01-01

When Argentina's state-owned utility, operating in northern Patagonia, sold off hydro-electric generating plants in 1993, they were bought by several North American utility companies. This article looks at the problems these companies encountered and examines whether the enterprise has shown itself to be economically valuable. (UK)

Kaolin clays from Patagonia - Argentina. Relationship between the mineralogy and ceramic properties; Arcillas caolinicas de la Patagonia argentina. Relacion entre la mineralogia y las propiedades ceramicas

Energy Technology Data Exchange (ETDEWEB)

Factorovich, J.C.; Badino, D. [Piedra Grande S.A., Buenos Aires (Argentina); Cravero, F.; Dominguez, E. [Universidad Nacional del Sur, Bahia Blanca (Argentina). Dept. de Geologia

1997-12-31

The mineralogy, grain size distribution, chemical composition, S and C contents, plasticity, and cationic exchange capacity are determined in the sedimentary kaolinitic clays from the clay pits Puma Negra, Puma Gris, Tincar Super; and Chenque and Cardenal located in Santa Cruz and Chubut Provinces. Mineralogy and Particle size distribution of > 5, 5-2 and <2{mu} fractions are determined. Modulus of rupture, 1100 and 1250 deg C shrinkage and water absorption and whiteness are found. It is accomplished a statistics correlation between the characteristics of grain size distribution, mineralogy, and other physical properties with the main ceramic properties to understand its influence in the ceramic process. (author) 5 refs., 2 tabs.

UVR-induced photoinhibition of summer marine phytoplankton communities from Patagonia

NARCIS (Netherlands)

Villafane, Virginia E.; Janknegt, Paul J.; de Graaff, Marco; Visser, Ronald J. W.; de Poll, Willem H. van; Buma, Anita G. J.; Helbling, E. Walter

During austral summer 2006, experiments were carried out to evaluate the effects of ultraviolet radiation (UVR, 280-400 nm) on carbon fixation of natural phytoplankton assemblages from Patagonia (Argentina). Surface water samples were collected (ca. 100 m offshore) at mid morning using an

Development of the Cerro solo deposit and uranium favorability of the San Jorge Gulf Basin, province of Chubut

International Nuclear Information System (INIS)

Navarra, P.R.; Benitez, A.F.

1997-01-01

In the future the uranium exploration activities of CNEA would tend to improve the knowledge of geology and uranium favorability; to perform prospection tasks, and research and development in exploration technologies, to contribute to be in a position to meet the requirements of the country in the long term. On the other hand, a strong growth of nuclear capacity is expected in the first two decades of the next century. Based on its promising grade, the Cerro Solo uranium ore deposit was selected in 1990 by the CNEA to carry out an assessment project. The intensive exploration level was accomplished, as follows: definition of general characteristics of the main orebodies; detailed geologic studies; estimation of resources with adequate data; and preliminary selection of mining-milling methods to estimate the potential profitability of the project. The deposit belongs to the sandstone type. The mineralized layers are distributed into the fluvial sandstones and conglomerates of the cretaceous Chubut Group, lying 50 to 130 m deep Resources of the deposit, with an average grade of 0.3% U, in tonnes of recoverable uranium at costs of up to $80/kg U, are: Reasonable Assured Resources (RAR): 800 t U, Estimated Additional Resources, Category I (EAR-I): 2100 t U. Follow-up drilling programmes are being performed at present in some of the target sites defined in the paleochannel that hosts the Cerro Solo deposit, in order to establish the hypothetical resources of the area. The sites were determined as a result of the exploration that CNEA conducted in the Pichinan uranium district. Recently a regional research project was formulated, for the detailed exploration in the San Jorge Gulf Basin, where the Chubut Group is distributed. 17 refs, 4 figs

New records of water mites (Acari: Hydrachnidia, Halacaroidea) from Patagonia (Chile)

NARCIS (Netherlands)

Pešić, V.; Smit, H.; Datry, T.

2010-01-01

New records of water mite species (Acari: Hydrachnidia, Halacaroidea) from Patagonia (Southern Chile) are reported. Four species, Anisitsiellides australis Smit, 2002, Peregrinacarus falklandensis Bartsch, 2001, Lobohalacarus weberi (Romijn & Viets, 1924) and Soldanellonyx monardi Walter, 1919 are

Difilobotriasis humana en la Patagonia, Argentina Human diphyllobothriasis in Patagonia, Argentina

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Liliana Semenas

1997-06-01

Full Text Available OBJETIVO: El objetivo del trabajo fué detectar hospedadores humanos en la zona andino patagónica argentina, teniendo en cuenta las prácticas de pesca desportiva y la importancia de los salmónidos dentro de la zona. MATERIAL Y METODO: Entre 1986 y 1995 se implementaron Campañas de Información en los laboratorios de Análisis Clínicos de la región andinopatagónica argentina, destinadas a lograr una detección más eficiente de la difilobotriasis, a través de análisis coproparasitológicos. RESULTADOS: Adicionalmente, se confeccionaron planillas destinadas a recoger información sobre las características de la infección, del tratamiento y del paciente. Durante este período se detectaron 13 nuevos casos humanos, por identificación directa del parásito o por la presencia de huevos en materia fecal. Las características de las infecciones responden a las descriptas para el género Diphyllobothrium. CONCLUSIONES: En la región, los salmónidos son los peces predilectos en la pesca deportiva. Estos peces, frecuentemente parasitados con larvas, constituyen la principal fuente de contagio para el hombre al ser consumidos insuficientemente cocidos o ahumados en frío.OBJECTIVE: In view of the amateur fishing practices and the importance of salmonids in the region the study sets out to detect human hosts in the Andean-Patagonian zone. MATERIAL AND METHOD: Information campaigns were carried out by Clinical Analysis Laboratories of Andean Patagonia between 1986 and 1995 to detect diphyllobothriasis more efficiently by means of coproparasitological analysis. RESULTS: Further, forms were prepared for the collection of information about infection, treatment and the characteristics of the human host. During this period 13 new cases were registered either through direct identification of the parasite or through the presence of eggs in the faeces. The characteristics of infection are similar to those described for the genus Diphyllobothrium

Ploidy levels and reproductive behaviour in invasive Hieracium pilosella in Patagonia

Czech Academy of Sciences Publication Activity Database

Krahulec, František; Krahulcová, Anna

2011-01-01

Roč. 11, - (2011), s. 25-31 ISSN 1619-0033 R&D Projects: GA ČR GA206/08/0890 Institutional research plan: CEZ:AV0Z60050516 Keywords : Patagonia * ploidy levels * hybridization Subject RIV: EF - Botanics

El patrimonio industrial petrolero en la Patagonia: Comodoro Rivadavia (Argentina y Cerro Sombrero (Chile. Una perspectiva comparada

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Pía Acevedo Méndez

2016-01-01

Full Text Available El hallazgo de petróleo en Comodoro Rivadavia (Chubut, Argentina y en Manantiales (Tierra del Fuego, lado chileno, motivó la construcción de espacios socioproductivos bajo el modelo de Company Towns. En el caso argentino la empresa estatal Yacimientos Petrolíferos Fiscales (Y.P.F creó el Campamento Central y la Empresa Nacional del Petróleo (ENAP creó Cerro Sombrero en Chile, los que en la década de 1970 formaron dos tejidos urbanos (barrio en el caso argentino y pueblo en el caso chileno. En esta dinámica se transformó el modo de habitar de ambos espacios, que se convirtieron en potenciales elementos turísticos, teniendo en cuenta que desde el año 2014 poseen reconocimiento patrimonial relacionado con su pasado petrolero y su arquitectura moderna. El objetivo es comparar cómo ambas empresas petroleras estatales construyeron dichos espacios “urbanos” y sus comunidades sociolaborales e indagar en la relación identidad/ patrimonio de ypefeanos y enapinos.

"Jejenes" (Diptera: Simuliidae of Nahuel Huapi National Park, Patagonia, Argentina: Preliminary results "Jejenes" (Diptera: Simuliidae del Parque Nacional Nahuel Huapi, Patagonia, Argentina: Resultados preliminares

Directory of Open Access Journals (Sweden)

Luis M. Hernández

2009-06-01

Full Text Available The Simuliidae is a family of Diptera with approximately 2072 described species worldwide. The females of the majority of the species feed from vertebrates' blood, which makes them a significant plague that affects both men as well as cattle, birds, and other vertebrates. The objective of this paper is to create an inventory of Simuliidae and to reveal certain aspects of the biology and distribution of this family of aquatic insects in the Nahuel Huapi National Park. Moreover, information on the zoogeography of Simuliidae in Patagonia is provided. Five genera, 3 subgenera and 32 species Simuliidae are recorded from Patagonia: Cnesia (three spp., Cnesiamima (one sp., Gigantodax (14 spp., Paraustrosimulium (one sp., Simulium (Ectemnaspis (one sp., S. (Psaroniocompsa (one sp. and S. ( Pternaspatha (11 spp., At present, we have collected all five genera, one subgenus of Simulium (Pternaspatha, and 19 species of Simuliidae in the park, which amounts to 57% of the Simuliidae fauna in this area. Puerto Blest, a characteristic area of the High-Andean phytogeographical province (humid forest, showed the highest diversity of Simuliidae.Los simúlidos pertenecen a una familia de Diptera (Simuliidae con alrededor de 2.072 especies descritas a nivel mundial. Las hembras de la mayoría de las especies se alimentan con sangre de vertebrados, lo cual las convierte en importantes plagas que afectan tanto al hombre como al ganado, aves y otros vertebrados. Los objetivos de este trabajo son llevar a cabo un inventario de Simuliidae y dar a conocer algunos aspectos de la biología y la distribución de esta familia de insectos acuáticos en el Parque Nacional Nahuel Huapi, Argentina. Además, se proporciona información sobre la biogeografía de Simuliidae en la Patagonia. Cinco géneros, un subgénero y 32 especies de simúlidos han sido registrados para Patagonia: Cnesia (3 spp., Cnesiamima (1 sp., Gigantodax (14 spp., Paraustrosimulium (1 sp., Simulium

Crecimiento y desarrollo de una población infanto juvenil de la provincia de Chubut

Directory of Open Access Journals (Sweden)

Torres, María Fernanda

1999-01-01

Full Text Available La diferenciación y adaptación ontogenética son temas centrales en antropología biológica por cuanto su modificación puede afectar la dinámica evolutiva poblacional. Numerosos factores estresantes actúan provocando variación en la expresión fenotípica y nuevas respuestas adaptativas. En el presente trabajo se determinó el crecimiento de niños de 5 a 14 años contrastando con estándares internacionales. La muestra se constituyó con 473 escolares de Río Mayo (Chubut, de ambos sexos. Se relevaron y calcularon variables corporales. Para la comparación con los estándares los datos fueron convertidos a escores z y contrastados además mediante pruebas de Wilcoxon. La estadística empleada consistió en análisis multifactorial de la varianza y pruebas de LSD. Si bien hubo crecimiento en todos los grupos etáreos analizados, los valores obtenidos difirieron significativamente de los correspondientes al estándar. En varones, a excepción del pliegue subescapular, que presentó escores z superiores al estándar las restantes variables se ubicaron entre 0 y -2 DS, siendo más afectadas las estaturas total y sentado y el área muscular. En mujeres, se observó una situación similar a excepción del área adiposa y la masa corporal, con valores mayores al estándar. Estos resultados evidencian la presencia de una desnutrición que abarca toda la franja etárea. La disminución de la talla y el aumento del tejido adiposo constituyen sin duda, respuestas adaptativas que permiten la supervivencia de los individuos frente a la injuria nutricional.

Late cretaceous aquatic plant world in Patagonia, Argentina.

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N Rubén Cúneo

Full Text Available In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The La Colonia Formation is a geological unit deposited during a Maastrichtian-Danian transgressive episode of the South Atlantic Ocean. This event resulted in the deposition of a series of fine-grained sediments associated with lagoon systems occurring along irregular coastal plains in northern Patagonia. These deposits preserved a diverse biota, including aquatic and terrestrial plants and animals. The aquatic macrophytes can be broadly divided into two groups: free-floating and rooted, the latter with emergent or floating leaves. Free-floating macrophytes include ferns in Salviniaceae (Azolla and Paleoazolla and a monocot (Araceae. Floating microphytes include green algae (Botryoccocus, Pediastrum and Zygnemataceae. Among the rooted components, marsileaceous water ferns (including Regnellidium and an extinct form and the eudicot angiosperm Nelumbo (Nelumbonaceae are the dominant groups. Terrestrial plants occurring in the vegetation surrounding the lagoons include monocots (palms and Typhaceae, ferns with affinities to Dicksoniaceae, conifers, and dicots. A reconstruction of the aquatic plant paleocommuniy is provided based on the distribution of the fossils along a freshwater horizon within the La Colonia Formation. This contribution constitutes the first reconstruction of a Cretaceous aquatic habitat for southern South America.

Late Cretaceous Aquatic Plant World in Patagonia, Argentina

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Cúneo, N. Rubén; Gandolfo, María A.; Zamaloa, María C.; Hermsen, Elizabeth

2014-01-01

In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The La Colonia Formation is a geological unit deposited during a Maastrichtian-Danian transgressive episode of the South Atlantic Ocean. This event resulted in the deposition of a series of fine-grained sediments associated with lagoon systems occurring along irregular coastal plains in northern Patagonia. These deposits preserved a diverse biota, including aquatic and terrestrial plants and animals. The aquatic macrophytes can be broadly divided into two groups: free-floating and rooted, the latter with emergent or floating leaves. Free-floating macrophytes include ferns in Salviniaceae (Azolla and Paleoazolla) and a monocot (Araceae). Floating microphytes include green algae (Botryoccocus, Pediastrum and Zygnemataceae). Among the rooted components, marsileaceous water ferns (including Regnellidium and an extinct form) and the eudicot angiosperm Nelumbo (Nelumbonaceae) are the dominant groups. Terrestrial plants occurring in the vegetation surrounding the lagoons include monocots (palms and Typhaceae), ferns with affinities to Dicksoniaceae, conifers, and dicots. A reconstruction of the aquatic plant paleocommuniy is provided based on the distribution of the fossils along a freshwater horizon within the La Colonia Formation. This contribution constitutes the first reconstruction of a Cretaceous aquatic habitat for southern South America. PMID:25148081

Kaolin clays from Patagonia - Argentina. Relationship between the mineralogy and ceramic properties

International Nuclear Information System (INIS)

Factorovich, J.C.; Badino, D.; Cravero, F.; Dominguez, E.

1997-01-01

The mineralogy, grain size distribution, chemical composition, S and C contents, plasticity, and cationic exchange capacity are determined in the sedimentary kaolinitic clays from the clay pits Puma Negra, Puma Gris, Tincar Super; and Chenque and Cardenal located in Santa Cruz and Chubut Provinces. Mineralogy and Particle size distribution of > 5, 5-2 and <2μ fractions are determined. Modulus of rupture, 1100 and 1250 deg C shrinkage and water absorption and whiteness are found. It is accomplished a statistics correlation between the characteristics of grain size distribution, mineralogy, and other physical properties with the main ceramic properties to understand its influence in the ceramic process. (author)

OSTEOMETRÍA DE VICUGNA VICUGNA MOLINA, 1782 EN EL PLEISTOCENO FINAL DE PATAGONIA MERIDIONAL CHILENA: IMPLICANCIAS PALEOECOLÓGICAS Y BIOGEOGRÁFICAS / Osteometry of Vicugna vicugna Molina, 1782 in the late Pleistocene of southern chilean Patagonia

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Rafael Labarca Encina

2009-12-01

Full Text Available  Se presenta un análisis osteométrico uni y multivariado con los materiales fósiles -principalmente huesos cortos y falanges- de Vicugna sp. del yacimiento Cueva Lago Sofía 4 (13500 – 11000 AP, ubicado en la provincia de Última Esperanza (Región de Magallanes, Chile. Los resultados indican que los elementos analizados poseen un tamaño compatible con los registrados para Vicugna vicugna, no superando en ningún caso a los especímenes conocidos para Vicugna gracilis del Pleistoceno de la región Pampeana. Esto confirma la información morfológica y de ADN antiguo que indicaba la presencia de Vicugna vicugna en la Patagonia meridional chilena. Se discuten los resultados en términos taxonómicos, biogeográficos y paleoecológicos sugiriendo que la presencia de este taxón fuera de su rango actual de distribución se debió a las condiciones ambientales compartidas entre la Puna y Patagonia austral durante la transición Pleistoceno-Holoceno. La extinción de V. vicugna se habría debido al impacto de los cambios climáticos ocurridos al inicio del Holoceno producto de su dieta pastadora y etología no migratoria y territorial, a lo que se habría sumado una caza por parte de depredadores humanos y no humanos.Palabras clave: género Vicugna, osteometría, Pleistoceno, Patagonia AbstractThis contribution presents the results of single and multi-variable osteometric analyses performed on a sample of short bones and phalanxes assigned to Vicugna sp. from Lago Sofía Cave 4 site (13500 – 11000 BP, Región de Magallanes, Chile. The elements analyzed show a similar size to the reference collections for Vicugna vicugna, and do not exceed the metrics for the pampean pleistocenic specimens of Vicugna gracilis. This confirms the morphological and ancient DNA data that indicated the presence of vicuña in southern Chilean Patagonia. The taxonomic, biogeographic and palaeoecologic discussion of these results, suggests that the presence of this

Trabajo femenino en la industria petrolera de Chubut (1919-1962

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Graciela Ciselli

2002-01-01

Full Text Available El artículo compara el trabajo femenino -extradoméstico y doméstico- en dos pueblos de empresas petroleras -la estatal Yacimientos Petrolíferos Fiscales y la privada Astra- ubicadas al norte de Comodoro Rivadavia en la Patagonia Argentina, durante dos épocas: 1919/1945 y 1946/1962. En el primer período se recuperan las formas en que las mujeres aprendieron las tareas femeninas orientadas al trabajo doméstico hogareño. Este aprendizaje les serviría, cuando decidieron o necesitaron, para insertase en el mercado laboral en ocupaciones afines (cocineras, mucamas, lavanderas. En el segundo período, como consecuencia de los cambios sociales, culturales y económicos ocurridos a nivel nacional y local, surgieron para las mujeres nuevas oportunidades en viejas ocupaciones predominantemente masculinas, de las que surgieron v.gr. las telefonistas y enfermeras.

Latest Pleistocene and Holocene Glacier Fluctuations in southernmost Patagonia

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Menounos, B.; Maurer, M.; Clague, J. J.; osborn, G.; Ponce, F.; Davis, P. T.; Rabassa, J.; Coronato, A.; Marr, R.

2011-12-01

Summer insolation has been proposed to explain long-term glacier fluctuations during the Holocene. If correct, the record of glacier fluctuations at high latitudes in the Southern Hemisphere should differ from that in the Northern Hemisphere. Testing this insolation hypothesis has been hampered by dating uncertainties of many Holocene glacier chronologies from Patagonia. We report on our ongoing research aimed at developing a regional glacier chronology at the southern end of the Andes north and west of Ushuaia, Argentina. We have found evidence for an advance of cirque glaciers at the end of the Pleistocene; one or locally two closely spaced moraines extend up to 2 km beyond Little Ice Age moraines. Radiocarbon dating of terrestrial macrofossils recovered from basal sediments behind two of these moraines yielded ages of 10,320 ± 25 and 10,330 ± 30 14C yr BP. These moraines may record glacier advances coeval with the Antarctic Cold Reversal; surface exposure dating of these moraines is currently in progress to test this hypothesis. We find no evidence of Holocene moraines older than 6800 14C yr BP, based on the distribution of Hudson tephra of that age. At some sites, there is evidence for an early Neoglacial advance of glaciers slightly beyond (Peru. We have documented multiple wood mats with stumps in growth position separated by till units in a 100 m section of the northeast lateral moraine at Stoppani Glacier (54.78 S, 68.98 W), 50 km west of Ushuaia. Ten radiocarbon ages on these wood mats range in age from 3510 ± 15 to 135 ± 15 14C yr BP. The mats decrease in age up-section; many overlap with published age ranges for Neoglacial advances in western Canada. Taken together, these data: a) do not support the summer insolation hypothesis for Holocene glacier fluctuations in southernmost Patagonia; b) confirm paleobotanical evidence for a warm, dry early Holocene; and c) suggest that many Neoglacial advances in southernmost Patagonia and western North America

Fe-Ni Micrometorites from Upper Jurassic Cañadon Asfalto Fm., Patagonia, Argentina

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Matteini, M.; Hauser, N.; Cabaleri, N.; Silva Nieto, D.; Cuadros, F. A.; Reyes, S.

2014-09-01

Microspherules from an upper Jurassic sediments from Patagonia, show mineralogical, geochemical and textural features very similar to those reported for I-type micrometeorites whereas some spherules are interpreted as typical G-type micrometeorites.

Geochronologic evidence of a large magmatic province in northern Patagonia encompassing the Permian-Triassic boundary

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Luppo, Tomás; López de Luchi, Mónica G.; Rapalini, Augusto E.; Martínez Dopico, Carmen I.; Fanning, Christopher M.

2018-03-01

The Los Menucos Complex (northern Patagonia) consists of ∼6 km thick succession of acidic and intermediate volcanic and pyroclastic products, which has been traditionally assigned to the Middle/Late Triassic. New U/Pb (SHRIMP) zircon crystallization ages of 257 ± 2 Ma at the base, 252 ± 2 Ma at an intermediate level and 248 ± 2 Ma near the top of the sequence, indicate that this volcanic event took place in about 10 Ma around the Permian-Triassic boundary. This volcanism can now be considered as the effusive terms of the neighboring and coeval La Esperanza Plutono-Volcanic Complex. This indicates that the climax of activity of a large magmatic province in northern Patagonia was coetaneous with the end-Permian mass extinctions. Likely correlation of La Esperanza- Los Menucos magmatic province with similar volcanic and plutonic rocks across other areas of northern Patagonia suggest a much larger extension than previously envisaged for this event. Its age, large volume and explosive nature suggest that the previously ignored potential role that this volcanism might have played in climatic deterioration around the Permian-Triassic boundary should be investigated.

Estado del conocimiento taxonómico de la fauna de Chironomidae (Diptera: Nematocera de la Patagonia

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Mariano DONATO

2009-01-01

Full Text Available La familia Chironomidae (Diptera: Nematocera es uno de los grupos de insectos más ampliamente distribuidos y abundantes en cuerpos de agua dulce. Los representantes de esta familia pueden explotar áreas con amplios gradientes ambientales. La información que se presenta está basada en la recopilación de datos distribucionales bibliográficos, del estudio del material tipo de las especies de Chironomidae depositadas en el Natural History Museum (UK y del material de colección del Museo de La Plata (Argentina. En la Patagonia, se registran 9 subfamilias, la subfamilia monotípica Chilenomyiinae es endémica de esta área. Dentro de estas subfamilias, 53 de los 111 géneros conocidos para América del Sur están presentes en la Patagonia. Del total de géneros de la Patagonia, el 20 % es endémico y 7 de ellos muestran relaciones transantárticas. En la Patagonia, se registran 177 especies de Chironomidae, el 98% de éstas son endémicas, el 3 % son consideradas nomina dubia y el 17% requiere revisión ya que su ubicación sistemática es dudosa. Las descripciones originales de las especies patagónicas de Chironomidae están basadas principalmente sobre machos (n=58 y machos y hembras (n=43, ambas representan el 57% del total; el resto de las especies han sido descriptas con diferentes combinaciones de estadios del ciclo de desarrollo.

A Combined Observational and Modeling Approach to Study Modern Dust Transport from the Patagonia Desert to East Antarctica

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Gasso, S.; Stein, A.; Marino, F.; Castellano, E.; Udisti, R.; Ceratto, J.

2010-01-01

The understanding of present atmospheric transport processes from Southern Hemisphere (SH) landmasses to Antarctica can improve the interpretation of stratigraphic data in Antarctic ice cores. In addition, long range transport can deliver key nutrients normally not available to marine ecosystems in the Southern Ocean and may trigger or enhance primary productivity. However, there is a dearth of observational based studies of dust transport in the SH. This work aims to improve current understanding of dust transport in the SH by showing a characterization of two dust events originating in the Patagonia desert (south end of South America). The approach is based on a combined and complementary use of satellite retrievals (detectors MISR, MODIS, GLAS ,POLDER, OMI,), transport model simulation (HYSPLIT) and surface observations near the sources and aerosol measurements in Antarctica (Neumayer and Concordia sites). Satellite imagery and visibility observations confirm dust emission in a stretch of dry lakes along the coast of the Tierra del Fuego (TdF) island (approx.54deg S) and from the shores of the Colihue Huapi lake in Central Patagonia (approx.46deg S) in February 2005. Model simulations initialized by these observations reproduce the timing of an observed increase in dust concentration at the Concordia Station and some of the observed increases in atmospheric aerosol absorption (here used as a dust proxy) in the Neumayer station. The TdF sources were the largest contributors of dust at both sites. The transit times from TdF to the Neumayer and Concordia sites are 6-7 and 9-10 days respectively. Lidar observations and model outputs coincide in placing most of the dust cloud in the boundary layer and suggest significant de- position over the ocean immediately downwind. Boundary layer dust was detected as far as 1800 km from the source and approx.800 km north of the South Georgia Island over the central sub-Antarctic Atlantic Ocean. Although the analysis suggests the

DETERMINACIÓN DE SISTEMAS FISIOGRÁFICOS PARA EL MANEJO DE RECURSOS NATURALES EN CUENCAS HIDROGRÁFICAS. ARROYOS LOS BERROS Y VENTANA, RÍO NEGRO

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Ana Paula Salcedo

2007-12-01

Full Text Available El paisaje patagónico se caracteriza en líneas generales por la cordillera de los Andes al Oeste, las mesetas de origen sedimentario y basáltico en la porción central y los valles y faldeos dispuestos en sentido Oeste-Este. Dentro de la unidad de mesetas basálticas el macizo de Somuncura es el de mayor dimensión en la Patagonia, ocupando una importante superficie de las provincias de Río Negro y Chubut. El manto basáltico que lo constituye actúa como un gran reservorio del agua que infiltra producto de las precipitaciones, lo que da lugar a la formación de numerosas vertientes en la periferia de la meseta, siendo un importante recurso para el asentamiento humano y el desarrollo de actividades agrícolas y ganaderas. Sin embargo, durante las últimas décadas, distintos factores han confluido en detrimento de las potencialidades para el desarrollo rural en la región, conllevando a un progresivo despoblamiento, a la retracción de las actividades productivas e incluso al abandono de los campos.

La proyección colonial de Chile a la Patagonia Insular en el siglo XVIII

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Urbina Carrasco, María Ximena

2011-12-01

Full Text Available In this article, the geopolitical consequences of the shipwreck of the English frigate Wager and the landfall of the ship Anna into the coasts of the Western Insular Patagonia in 1741 are presented, which were part of the fleet of George Anson. The news reporting the English presence in the deserted and unknown insular and coastal territory southernmost Chiloé, and which had disseminated towards the end of the continent, promoted the deployment of different actions tending to make presence noted, such as military and missionary expeditions, fort establishment and area patrols. None of the latter implied a permanent settlement or effective incorporation of such border, although they indeed involved the creation of a «mobile frontier» for Chiloé and the development of a Western Patagonia image.

Este artículo presenta las consecuencias geopolíticas del naufragio de la fragata inglesa Wager y la recalada de otro barco, el Anna, que formaban parte de la flota de George Anson, en las costas de la Patagonia Occidental Insular en 1741. La noticia de la presencia inglesa en el despoblado y desconocido territorio insular y bordemarino al sur de Chiloé, y que se proyectaba al fin del continente, generó el despliegue de acciones tendentes a marcar presencia, como expediciones militares y misionales, la fundación de un fuerte y el patrullaje por la zona. Nada de esto se tradujo en un asentamiento permanente o incorporación efectiva de dicha frontera, pero si en la conformación de una «frontera móvil» de Chiloé, y la construcción de una imagen de la Patagonia Occidental.

Modulation of Fire Regimes by Vegetation and Site Type in Southwestern Patagonia Since 13 ka

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Patricio I. Moreno

2018-04-01

Full Text Available The degree to which vegetation and site type have influenced fire regimes through the Holocene has not been investigated in detail in the temperate ecosystems of southern Patagonia. Here we present a first attempt using a paired-basin approach to study the evolution of fire regimes in sectors dominated by humid Nothofagus forests and the xeric Patagonian steppe in the Magallanes region of Chilean Patagonia (51°S. We analyzed sediment cores from two small lakes and a bog located within the same climate zone on opposite sides of the forest-steppe ecotone, ~28 km apart. The position of this biological boundary east of the Andes is controlled by the strength and position of the southern westerly winds, which constitute the sole source of precipitation throughout western Patagonia. Our results indicate that fires have occurred in the study region repeated times over the last ~13,000 years at bi- and tridecadal timescales. Sectors currently dominated by Patagonian steppe feature high frequency and low magnitude of local fires, and vice versa in humid forests. Climate-driven expansion of Nothofagus scrubland/woodland into steppe environments over the last ~4,200 years increased the magnitude and lowered the frequency of fire events, culminating with peak Nothofagus abundance, fire magnitude and frequency during the last millennium. We also detect divergences between lake-based vs. bog-based paleofire histories among paired sites located within the Patagonian steppe, ~12 km apart, which we attribute to local burning of the bog at times of lowered water table. This divergence suggests to us that bog-based vegetation and fire histories exacerbate a local, azonal, signal blurring extra-local or regional regimes, thus accounting for some discrepancies in the Quaternary paleovegetation/paleoclimate literature of southern Patagonia.

The Usefulness of Edible and Medicinal Fabaceae in Argentine and Chilean Patagonia: Environmental Availability and Other Sources of Supply

OpenAIRE

Molares, Soledad; Ladio, Ana

2011-01-01

Fabaceae is of great ethnobotanical importance in indigenous and urban communities throughout the world. This work presents a revision of the use of Fabaceae as a food and/or medicinal resource in Argentine-Chilean Patagonia. It is based on a bibliographical analysis of 27 ethnobotanical sources and catalogues of regional flora. Approximately 234 wild species grow in Patagonia, mainly (60%) in arid environments, whilst the remainder belong to Sub-Antarctic forest. It was found that 12.8% (30 ...

Evaluation of the Cerro Solo nuclear ore, province of Chubut. On the economic parameters of the deposit. Pt. 3

International Nuclear Information System (INIS)

Navarra, P.R.; Sardin, P.G.; Urquiza, L.; Bernal, G.J.; Guzman Lobos, D.

1993-01-01

Preliminary results of the resources estimation carried out in the Cerro Solo uranium ore deposit, located in the Chubut Province, 1900 km SW from Buenos Aires and 380 Km W from Trelew, presented in tonnes of uranium recoverable at costs up to U$S 80/kgU, are as follows: a) Reasonable assured resources (indicated): 800 tU; b) Estimates Additional Resources (inferred): 2200 tU. Economic evaluation at the order-of-magnitude level, performed using the grade-tonnage model of the deposit, resulted a useful tool in the different stages of the project to identify the influence of technical parameters on the potential profitability. Research about feasibility of in-situ leaching method of exploitation for this deposit introduces an interesting alternative for future uranium production in the country. (Author)

Peronism and political citizenship in the Patagonia: the look of the magazine Argentina Austral (1946-1955)

OpenAIRE

Ruffini, Martha

2015-01-01

Desde 1929, y durante casi cuarenta años, en la Patagonia circuló la revista Argentina Austral. Esta continuidad fue facilitada por el sello original de la publicación que era propiedad de la empresa ganadera, comercial y naviera más importante del sur argentino: la Sociedad Anónima Importadora y Exportadora de la Patagonia, dirigida por la familia Braun-Menéndez Behety. La revista asumió una postura de demanda de ampliación de los derechos políticos de los habitantes del sur mientras expresa...

Eastern Andean environmental and climate synthesis for the last 2000 years BP from terrestrial pollen and charcoal records of Patagonia

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Sottile, G. D.; Echeverria, M. E.; Mancini, M. V.; Bianchi, M. M.; Marcos, M. A.; Bamonte, F. P.

2015-06-01

The Southern Hemisphere Westerly Winds (SWW) constitute an important zonal circulation system that dominates the dynamics of Southern Hemisphere mid-latitude climate. Little is known about climatic changes in the Southern South America in comparison to the Northern Hemisphere due to the low density of proxy records, and adequate chronology and sampling resolution to address environmental changes of the last 2000 years. Since 2009, new pollen and charcoal records from bog and lakes in northern and southern Patagonia at the east side of the Andes have been published with an adequate calibration of pollen assemblages related to modern vegetation and ecological behaviour. In this work we improve the chronological control of some eastern Andean previously published sequences and integrate pollen and charcoal dataset available east of the Andes to interpret possible environmental and SWW variability at centennial time scales. Through the analysis of modern and past hydric balance dynamics we compare these scenarios with other western Andean SWW sensitive proxy records for the last 2000 years. Due to the distinct precipitation regimes that exist between Northern (40-45° S) and Southern Patagonia (48-52° S) pollen sites locations, shifts on latitudinal and strength of the SWW results in large changes on hydric availability on forest and steppe communities. Therefore, we can interpret fossil pollen dataset as changes on paleohydric balance at every single site by the construction of paleohydric indices and comparison to charcoal records during the last 2000 cal yrs BP. Our composite pollen-based Northern and Southern Patagonia indices can be interpreted as changes in latitudinal variation and intensity of the SWW respectively. Dataset integration suggest poleward SWW between 2000 and 750 cal yrs BP and northward-weaker SWW during the Little Ice Age (750-200 cal yrs BP). These SWW variations are synchronous to Patagonian fire activity major shifts. We found an in phase

Formas terminales de Hippidion (Mammalia, Perissodactyla de los yacimientos del Pleistoceno Tardio-Holoceno de la Patagonia (Argentina y Chile

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Prado, J. L.

1987-04-01

Full Text Available The present study is a revision of the terminal forms of the South-American horses coming from the archeological sites of Patagonia. They are compared with those from the Northwest of Argentine. The study also includes paleoenvironmental and cronological related aspects.El presente estudio comprende una revisión de las formas terminales de caballos sudamericanos recuperados de sitios arqueológicos de la Patagonia. Se comparan con las formas del noroeste argentino. Incluye aspectos paleoambientales y cronológicos relacionados.

Trace elements deposition in the Tierra del Fuego region (south Patagonia) by using lichen transplants after the Puyehue-Cordón Caulle (north Patagonia) volcanic eruption in 2011.

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Conti, Marcelo Enrique; Jasan, Raquel; Finoia, Maria Grazia; Iavicoli, Ivo; Plá, Rita

2016-04-01

Lichen Usnea barbata transplants were tested as a biomonitor of atmospheric deposition in an apparently pristine environment that is Tierra del Fuego region (Patagonia, Argentina). The present survey is connected with the volcanic eruption that started in north Patagonia on June 4, 2011 from the Puyehue-Cordón Caulle volcano, Chile (north Patagonia, at 1700 km of distance of our sampling sites). Lichens were collected in September 2011 (one month of exposure) and September 2012 (1 year of exposure) in 27 sites covering the northern region of the province where trees are not present. The atmospheric deposition of 27 elements by using Neutron Activation Analysis (NAA) was determined in the collected samples. The first aim of the study was to evaluate the influence of the volcanic eruption on the regional atmospheric deposition comparing our results with baseline data we determined in U. barbata in 2006 in the same sites. The second aim was to test possible patterns of bioaccumulation between the two sampling campaigns after the volcanic eruption. With respect to 2006 baseline levels, we found significant higher levels for As, Ba, Co, Cr, Cs, Na, Sb and U in lichens collected after 1 month of exposure (first sampling campaign--2011). Between the two sampling campaigns (2011-2012) after the eruption, lichens reflected the natural contamination by volcanic ashes with significantly higher median levels of Br, Cr, Fe, K, Na, Sc, and Se. Results confirmed the very good aptitude of U. barbata to reflect the levels of elements in the environment at global scale and to reflect the volcanic emissions at distant places. Volcanic eruptions cause the emission in the atmosphere of elevated levels of particulate matter. In this regard, our findings demonstrate the importance to evaluate the metal composition of the particles to avoid possible health effects.

Sedimentology and paleoenvironments of the Las Chacritas carbonate paleolake, Cañadón Asfalto Formation (Jurassic), Patagonia, Argentina

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Cabaleri, Nora G.; Benavente, Cecilia A.

2013-02-01

The Las Chacritas Member is the lower part of the Cañadón Asfalto Formation (Jurassic). The unit is a completely continental limestone succession with volcanic contributions that were deposited during the development of the Cañadón Asfalto Rift Basin (Chubut province, Patagonia, Argentina). A detailed sedimentological analysis was performed in the Fossati depocenter to determine the paleoenvironments that developed in the context of this rift. The Las Chacritas Member represents a carbonate paleolake system with ramp-shaped margins associated with wetlands that were eventually affected by subaerial exposure and pedogenesis. This process is represented by three main subenvironments: a) a lacustrine setting sensu stricto (lacustrine limestone facies association), represented by Mudstones/Wackestones containing porifera spicules (F1), Intraclastic packstones (F6) and Tabular stromatolites (F10) in which deposition and diagenesis were entirely subaqueous; b) a palustrine setting (palustrine limestone facies association) containing Microbial Mudstones (F2), Intraclastic sandy packstone with ostracode remains (F3), Oncolitic packstone (F5), Brecciated limestone (F7) and Nodular-Mottled limestone (F8) representing shallow marginal areas affected by groundwater fluctuations and minor subaerial exposure; and c) a pedogenic paleoenvironment (pedogenic limestone facies association) including Intraclastic limestone (F4) and Packstones containing Microcodium (F9) facies displaying the major features of subaerial exposure, pedogenic diagenesis and the development of paleosols. The fluvial-palustrine-lacustrine succession shows a general shallow upward trend in which contraction-expansion cycles are represented (delimited by exposure and surface erosion). The variations in the successive formations reflect the responses to fluctuations in a combination of two major controls, the tectonic and local climatic variables. The predominance of the palustrine facies associations was

Insectos acuáticos de la Meseta del Somuncura, Patagonia, Argentina. Inventario preliminar Aquatic insects from Somuncura plateau, Patagonia, Argentina. Preliminary inventory

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Javier Muzón

2005-12-01

Full Text Available RESUMEN. Se brinda un inventario preliminar de los insectos acuáticos de la Meseta del Somuncura y su área de influencia (Patagonia, Argentina realizado sobre la base de colecciones y registros previos de especies pertenecientes a los órdenes Ephemeroptera, Odonata, Hemiptera (Heteroptera, Trichoptera, Diptera (familias Ceratopogonidae, Culicidae y Psychodidae y Coleoptera. Se han relevado diversos tipos de ambientes en 14 localidades. El número de especies registrado asciende a 78, agrupadas en 51 géneros y 26 familias, de las cuales 33 se citan por primera vez del área. De los taxa registrados 83% de los géneros corresponden a grupos de amplia distribución (neotropicales, americanos o cosmopolitas, mientras que 41% de las especies presentan una distribución patagónica o andina.ABSTRACT. A preliminary inventory of the aquatic insects from the Somuncura plateau and its area of influence (Patagonia, Argentina is presented. It was done on the basis of the study of collections and previous records of species belonging to the orders Ephemeroptera, Odonata, Hemiptera (Heteroptera, Trichoptera, Diptera (families Ceratopogonidae, Culicidae, and Psychodidae and Coleoptera. Different kinds of environments were surveyed in 14 localities. Seventy eigth species grouped in 51 genera and 26 families were registered, and 33 species are new records for the area. Eighty three % of the registered genera are widely distributed (neotropical, american or cosmopolitan, while 41 % of the species exhibit patagonic or andean distribution.

Glacial lakes of the Central and Patagonian Andes

Science.gov (United States)

Wilson, Ryan; Glasser, Neil F.; Reynolds, John M.; Harrison, Stephan; Anacona, Pablo Iribarren; Schaefer, Marius; Shannon, Sarah

2018-03-01

The prevalence and increased frequency of high-magnitude Glacial Lake Outburst Floods (GLOFs) in the Chilean and Argentinean Andes suggests this region will be prone to similar events in the future as glaciers continue to retreat and thin under a warming climate. Despite this situation, monitoring of glacial lake development in this region has been limited, with past investigations only covering relatively small regions of Patagonia. This study presents new glacial lake inventories for 1986, 2000 and 2016, covering the Central Andes, Northern Patagonia and Southern Patagonia. Our aim was to characterise the physical attributes, spatial distribution and temporal development of glacial lakes in these three sub-regions using Landsat satellite imagery and image datasets available in Google Earth and Bing Maps. Glacial lake water volume was also estimated using an empirical area-volume scaling approach. Results reveal that glacial lakes across the study area have increased in number (43%) and areal extent (7%) between 1986 and 2016. Such changes equate to a glacial lake water volume increase of 65 km3 during the 30-year observation period. However, glacial lake growth and emergence was shown to vary sub-regionally according to localised topography, meteorology, climate change, rate of glacier change and the availability of low gradient ice areas. These and other factors are likely to influence the occurrence of GLOFs in the future. This analysis represents the first large-scale census of glacial lakes in Chile and Argentina and will allow for a better understanding of lake development in this region, as well as, providing a basis for future GLOF risk assessments.

Combined U-Pb SHRIMP and Hf isotope study of the Late Paleozoic Yaminué Complex, Rio Negro Province, Argentina: Implications for the origin and evolution of the Patagonia composite terrane

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Carlos J. Chernicoff

2013-01-01

Combining geological and isotope data, as well as geophysical models, we identify the Yaminué Complex within the La Esperanza-Yaminué crustal block flanked by two other, distinct crustal blocks: the Eastern block which forms part of the Patagonia terrane sensu stricto, located in the eastern Patagonian region, and the Western block forming part of the Southern Patagonia terrane. Their origins and timing of amalgamation to form the Patagonia composite terrane are also discussed.

Aproximación a la emigración española a la provincia del Chubut: los yacimientos petrolíferos fiscales (1915-1933

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Castiñeira Castro, Víctor Manuel

1999-12-01

Full Text Available La ciudad de Comodoro Rivadavia, enclavada en la actual provincia argentina del Chubut, se convirtió a comienzos del presente siglo, y con motivo del descubrimiento en la zona de importantes yacimientos de petróleo, en un destacado foco de atracción de inmigración. A través del análisis de YPF, la empresa más influyente de la zona, observamos la importancia jugada por la colectividad española en este proceso, así como su carácter de inmigración no especializada tendente a ocupar los empleos menos reconocidos en la empresa.

LA PATAGONIA ORIENTAL SEGÚN UNA REAL CÉDULA de 1570 MENOSPRECIADA POR LA HISTORIOGRAFÍA CHILENA

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MANUEL RAVEST MORA

2005-12-01

Full Text Available Versa este trabajo sobre la Real Cédula de Felipe II que, en 1570, fusionó parte de la Patagonia Oriental con la Provincia del Río de la Plata, origen de la República Argentina, donde, al parecer, supieron del documento treinta años después de finalizado el debate con Chile acerca de los derechos al extremo meridional de América. Descubierta por un diplomático chileno, que informó de ella a su Cancillería en 1876 y la mencionó en un libro publicado en 1903, ha sido sistemáticamente ignorada por los escritores chilenos. Examina este trabajo las posibles causas de ese silencio historiográfico, como también las rectificaciones que la RC introduce en la tesis clásica o fundacional de Chile, formulada a mediados del XIX por Miguel Luis Amunátegui, según la cual ese país siempre ejerció jurisdicción sobre la totalidad de la Patagonia Oriental desde 1554This work deals with a 1570 Phillip the II Decree that fused a section of Atlantic Patagonia with the Rio de la Plata Province, origin of late Argentine Republic, who, apparently, learned about it thirty years after ended the discussion held with Chile in respect the rights of each country towards the southern extreme of America. Found by a chilean diplomat, who informed his Ministry of Foreign Affairs in 1876 and wrote about the document in a book published in 1903, it has been systematically ignored by chilean scholars. The work examines the possible causes for this historiographyc silence, and the rectifications that the Royal Decree introduces in the classical chilean thesis about Patagonia, enounced by Miguel Luis Amunategui in middle XIX century, according to which that whole territory always belonged to Chile since 1554

Evaluation of the Cerro Solo nuclear ore, province of Chubut. Geological characteristics of the deposit and of the basin. Pt. 2

International Nuclear Information System (INIS)

Benitez, A.F.; Fuente, A.; Maloberti, A.; Landi, V.A.; Bianchi, R.E.; Marveggio de Bianchi, N.; Gayone, M.R.

1993-01-01

The Cerro Solo uranium ore deposit, is located 420 km west from Trelew city, Chubut province, in the extra-andean. The geologic environment belongs to the northwest edge portion of the intracratonic San Jorge Gulf Basin. The uraniferous district is named Pichinanes Ridge district. The mineralization lies 25 to 130 m depth, and is hosted by Los Adobes formation aged Aptian-Albian, made up by conglomerates, sandstones, coarse-sandstones and less abundant siltstones and claystones. The Cerro Solo ore deposit that belongs to the sandstone type-uranium occurrences are lenticular or tabular shaped, associated with organic material and pyrite, generally roughly parallel to the bedding (Trend-Type). The uranium minerals are uraninite and coffinite associated with organic material and pyrite, and frequently hematite, goethite, calcite, siderite and barite are observed. (Author)

Flavonols, alkaloids, and antioxidant capacity of edible wild berberis species from patagonia.

Science.gov (United States)

Ruiz, Antonieta; Zapata, Moises; Sabando, Constanza; Bustamante, Luis; von Baer, Dietrich; Vergara, Carola; Mardones, Claudia

2014-12-24

There are 20 species of the Berberidaceae family described in Chile, whose fruits are edible and show high anthocyanin and hydroxycinnamic acid levels. Berberis microphylla G. Forst, commonly known as calafate, is the most extensively distributed. Flavonols and alkaloids in seed, pulp, skin, and whole calafate berry extracts and other Berberis were studied using HPLC-DAD-ESI-MS/MS and HPLC with fluorescence detector. Berry samples from different locations in Chilean Patagonia, including different phenological stages, were systematically addressed. Results were compared with other organs of the plant and with other Berberis species. Total flavonol concentration in calafate (n = 65) was 1.33 ± 0.54 μmol/g. Glycosyl metabolites of quercetin and isorhamnetin were the most abundant. Similar profiles were observed in calafate from distinct locations, but important differences were observed for the other edible Berberis species. Calafate pulp and skin have higher flavonol concentrations than seeds, and the maturation process reduced its levels. TEACCUPRAC and TEACABTS of whole calafate extracts and fractions are also explored. Finally, only berberine was detected in the fruit (0.001%), mainly in seeds. Results contribute to the promotion of this berry as a superfruit from Patagonia.

Little Ice Age advance and retreat of Glaciar Jorge Montt, Chilean Patagonia

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A. Rivera

2012-03-01

Full Text Available Glaciar Jorge Montt (48°20' S/73°30' W, one of the main tidewater glaciers of the Southern Patagonian Icefield (SPI, has experienced the greatest terminal retreat observed in Patagonia during the past century, with a recession of 19.5 km between 1898 and 2011. This retreat has revealed trees laying subglacially until 2003. These trees were dated using radiocarbon, yielding burial ages between 460 and 250 cal yrs BP. The presence of old growth forest during those dates indicates that Glaciar Jorge Montt was upvalley of its present position before the commonly recognized Little Ice Age (LIA period in Patagonia. The post-LIA retreat was most likely triggered by climatically induced changes during the 20th century; however, Glaciar Jorge Montt has responded more dramatically than its neighbours. The retreat of Jorge Montt opened a 19.5 km long fjord since 1898, which reaches depths in excess of 390 m. The bathymetry is well correlated with glacier retreat rates, suggesting that dynamic responses of the glacier are at least partially connected to near buoyancy conditions at the ice front, resulting in high calving fluxes, accelerating thinning rates and rapid ice velocities.

Chondrichthyans of the San Matías Gulf, Patagonia, Argentina Los condrictios del Golfo San Matías, Patagonia, Argentina

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María R PERIER

2011-12-01

Full Text Available The San Matías Gulf (SMG; 41°- 42° S; 64°- 65° W is the largest gulf in Northern Patagonia, Argentina. Up to date, the chondrichthyan fauna of this area has not been reported. Therefore, the aim of this work is to provide a list with species presence and biological characteristics of the chondrichthyans recorded in SMG during the last 30 years. A total of 13 sharks distributed in 11 families, 19 skates and rays distributed in six families, and one holocephalan have been so far recorded in SMG. From the zoogeographical point of view, this chondrichthyan fauna is a mixed assemblage of species typically found in the Argentinean and Magellanean Provinces. The holocephalan Callorhinchus callorynchus is the most landed chondricthyan of the local fishery. With it, five sharks and seven skates are also exploited.El Golfo San Matías (SMG; 41°- 42° S - 64°-65° O se encuentra ubicado en el norte de la Patagonia, Argentina. Hasta la fecha no se cuentan con reportes de la fauna de condrictios de esta zona. Por lo tanto, el objetivo de este trabajo es proporcionar una lista de la presencia y las características biológicas de los condrictios registrados en el SMG durante los últimos 30 años. Un total de 13 tiburones distribuidos en 11 familias, 19 batoideos distribuidos en seis familias y un holocefalo han sido reportados para la zona. Desde el punto de vista zoogeográfico, el SMG presenta un ensamble de especies pertenecientes a las Provincias Magallánica y Argentina. El holocefalo Callorhinchus callorynchus es el condrictio más desembarcado de la pesquería local. Con menor importancia son explotadas comercialmente, cinco especies de tiburones y siete de rayas.

Proyecto de Plaza-Embarcadero en Caleta Tortel, Región de Aysén, Patagonia de Chile / Embarcadero Plaza-Project in Tortel, Region of Aysen Patagonia, Chile.

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Medel Santibáñez, Paulina Andrea

2007-06-01

Full Text Available El proyecto de Título de Arquitectura, 2007, que se presenta tiene como objetivo central dar respuesta a necesidades reales, preservando y cuidando del medio local, tanto natural como sociocultural, dentro de la dinámica actual de cambios y apertura. Se reconoce los atributos y potencialidades propios de Caleta Tortel para preservar su identidad cultural y patrimonial a través de la consideración de la relación con su entorno, específicamente, reconociendo el vínculo entre la localidad y el mar como medio elemental que le da origen y permite su desarrollo. La “Plaza-Embarcadero" en Caleta Tortel es un conjunto de carácter público, de escala comunal y con un programa comunitario integrador y abierto para la interacción diaria y directa de los habitantes y visitantes.This work leading to the professional degree in architecture is an answer to certain needs of Caleta Tortel in the Chilean Patagonia, adapting itself to the local environment –social and natural- and to the changes of globalization. The core idea of this project is to preserve the spatial and economic link between the town and the sea. The proposed wharf is a meeting point for the neighbours and tourists.

Caracterización palinológica de las mieles de la llanura del río Senguerr (Chubut-Argentina

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Alicia Forcone

2000-01-01

Full Text Available Forcone, A. & Tellería, M. C. 2000. Caracterización palinológica de las mieles de la llanuradel río Senguerr (Chubut-Argentina. Darwiniana 38(3-4: 267-271.Con el fin de conocer las plantas melíferas de la llanura del río Senguerr, se realizó el análisispalinológico de 19 muestras de miel. El estudio permitió identificar 57 tipos morfológicos y demostrarque las principales fuentes de néctar pertenecen a las familias Fabaceae, Rosaceae, Brassicaceae yAsteraceae. Del total de muestras analizadas 9 resultaron mixtas y 10 monoflorales, de estas últimas, 8fueron de Melilotus sp. y 2 de Rosaceae. Las mieles estudiadas pueden ser caracterizadas por unaasociación polínica de Trifolieae, Brassicaceae, Rosaceae, Acaena sp., Glycyrrhiza astragalina Gillies exHook. & Arn. and Cyperaceae. En la mayoría de las muestras el contenido polínico fue inferior a 2000granos/gramo

Las relaciones sociales en la Meseta Norte de Chubut (1930-1970. Un abordaje desde la perspectiva poscolonial

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Ana María Troncoso

2012-01-01

Full Text Available Nuestro propósito es trabajar con determinados conceptos de la crítica poscolonial para intentar alguna interpretación y explicación acerca de las agencias posibles en los sujetos destinatarios de lo que llamamos «proyecto civilizador» del Estado argentino en la Meseta Central del norte de la provincia del Chubut, Argentina. En el período que proponemos revisar (1930-1970 las familias de la meseta chubutense fueron expuestas a una dinámica importante respecto a los medios de vida (fundamentalmente la tierra, como consecuencia del desarrollo del mercado y de la creciente presencia del estado. Para este trabajo hemos recurrido mayormente a relatos orales, además de documentos oficiales y biografías publicadas, que indican cambios relevantes en la constitución familiar, en especial en lo referente a la conformación de parentelas y a las características de las relaciones familiares y comunitarias. El relevamiento oral ha permitido construir historias de familias tendiendo a la reinterpretación que produce la memoria, con las negociaciones y reevaluaciones de lo acontecido y experimentado, exponiendo la puesta en práctica de racionalidades, estrategias versátiles y resignificaciones en este contexto dinámico, observables en la trama intergeneracional. Mediante los relatos se pueden historizar las comunidades, las parentelas, las familias y los individuos, escapando a la fascinación que producen las fuentes oficiales y sus derivados de sectores dominantes o serviles a él, cuya inercia hacia un enfoque teleológico implica desechar los temas y problemas que parecen estadios inferiores y superados, y que deja al margen a estos pobladores, estereotipándolos, generando un vacío de Historia. Así es que, estas voces legítimas y necesarias relativizan la linealidad de un proceso que supone imposiciones sin contrapuntos obligándonos a reflexionar sobre los posicionamientos y decisiones de grupos sociales subalternos y otrificados sobre

Doble difusión a partir de mediciones de microestructura en los canales Martínez y Baker, Patagonia chilena central (47,85°S

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Iván Pérez-Santos

2013-03-01

Full Text Available Con un microperfilador SCAMP (Self Contained Autonomous MicroProfile se detectó un proceso de Doble Difusión Convectiva (DDC, en los canales Martínez y Baker de la Patagonia central, Chile. Este perfilador midió temperatura y salinidad en la columna de agua con una resolución del orden de milímetros. El muestreo se efectuó en diciembre 2011, en 19 estaciones oceanográficas de ~55 m de profundidad. Los registros del microperfilador permitieron detectar la formación de escaleras termohalinas que caracterizan la formación de la DDC. Por medio del ángulo de Turner se confirmó que debajo de una capa superficial fuertemente estratificada (7-10 m se registraron eventos de DDC a profundidades entre 15 y 45 m. La DDC fue débil en la mayoría de los registros pero se evidenciaron eventos fuertes entre 15 y 40 m. En la capa subsuperficial, su origen se debió al intercalamiento de las masas aguas estuarinas (aguas frías y menos saladas encima de las oceánicas (aguas más cálidas y saladas, mientras que en la superficie la interacción océano-atmósfera favoreció su ocurrencia. La DDC en conjunto con el viento, las mareas y las ondas internas, puede constituir un mecanismo importante para la mezcla vertical, influenciando los flujos de calor, el hábitat de las especies marinas en estas profundidades y la exportación de carbono hacia los sedimentos.

Do coastal fronts influence bioerosion patterns along Patagonia? Late Quaternary ichnological tools from Golfo San Jorge

Science.gov (United States)

Richiano, Sebastián; Aguirre, Marina; Castellanos, Ignacio; Davies, Karen; Farinati, Ester

2017-12-01

Late Quaternary marine molluscan skeletal concentrations from Argentina constitute a remarkable record of variations in palaeoceanographical conditions during interglacial times (mainly ca. 125 ka to present). Particularly, the Golfo San Jorge coastal area represents an extraordinary geographical zone to target from different points of view, mainly due to its linkage between northern and southern Patagonia, characterized by particular and contrasting physico-chemical conditions with direct consequences for littoral marine communities, determining their composition and structure. Among varied biological activities controlled by different environmental factors (i.e., substrate nature, sedimentation rates, water depth, sea surface temperature, salinity, nutrients-productivity), bioerosion traces can provide palaeoenvironmental evidence with important implications for palaeoclimate interpretations. In addition, the application of bioerosion patterns regionally and through time is a recent valuable worthy palaeoenvironmental tool not as yet developed for Patagonia. We attempted to characterize, qualitatively/semiquantitatively, the ichnotaxonomic composition of the coastal area of northern Golfo San Jorge since the Late Pleistocene; to compare results with those obtained for other geographical areas along Patagonia and the Bonaerensian coastal sectors; lastly, to evaluate its palaeoenvironmental/palaeoclimatic significance in a clue area in terms of circulation patterns near the Southern Ocean climatic pump. At Bustamante (Northern Patagonia Frontal System) Domichnia traces were dominant during the Late Pleistocene while Praedichnia in the mid-Holocene. Bustamante exhibits the highest ichnodiversity for the whole Argentinean coastal area. Ichnodiversity is not strongly different between Late Pleistocene and mid-Holocene interglacials and compared to present; however, the relative abundance of some ichnotaxa (e.g., Oichnus, Iramena, Pennatichnus, at Camarones; Oichnus

Un suelo referible al periodo calido medieval en Patagonia Austral y Tierra del Fuego (Argentina. Aspectos cronologicos y paleoclimaticos

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Favier Dubois, C. M.

2002-08-01

Full Text Available Geoarchaeological work done in Southernmost Patagonia and in the north of Tierra del Fuego, have revealed the recurrent presence of a paedogenesis interval represented by a soil of an A-AC-C profile, with a mollic epipedon, in the upper section of eolian and colluvial deposits of the late Holocene. This soil is today buried in the sites that have been analyzed, while it remains exposed in other areas of the landscape. Radiocarbon dates obtained on materials placed below it (maximum ages and those obtained by OCR (Oxidizable Carbon Ratio in the AC horizon of this soil (minimum ages, indicate the beginning of its development around the year 1000 BP. Its chronology and environmental implications suggest a relationship with the medieval climatic fluctuations called Medieval Warm Period or Medieval Optimum in Europe. This period has correlates detected in Patagonia by dendroclimatic studies.Estudios geoarqueológicos realizados en 5 localidades de Patagonia austral y norte Tierra del Fuego han revelado la recurrente presencia de un suelo de perfil A-AC-C, de epipedon mólico, en depósitos eólicos y coluviales del Holoceno tardío. Este suelo se observa sepultado en los yacimientos arqueológicos analizados, mientras que permanece expuesto en otras posiciones del paisaje. Numerosas edades máximas y mínimas obtenidas por 14C y por la técnica de OCR (Oxidizable Carbon Ratio indican el comienzo de su desarrollo hacia el 1000 AP. Su cronología e implicancias ambientales permiten vincularlo con fluctuaciones climáticas desarrolladas durante el denominado Período Cálido Medieval u Optimo Medieval Europeo, con correlatos detectados en Patagonia a través de estudios dendroclimáticos.

Variability of Soil Types in Wetland Meadows in the South of the Chilean Patagonia Variabilidad de Tipos de Suelos en Las Vegas del Sur de la Patagonia Chilena

OpenAIRE

Ladislava Filipová; Radim Hédl; Nilo Covacevich C.

2010-01-01

The wetland meadows and pastures (vegas) of the agricultural zone of the Magallanes Region and the Chilean Patagonia are productive and intensively exploited ecosystems. However, there is scarce data about the typology and the physical and chemical properties of the soils that determine the agricultural potential of vegas sites. Sampling of the main horizons of 47 soil profiles was conducted throughout the area. The profiles were described in the field and consequently classified according to...

Ground level and Lidar monitoring of volcanic dust and dust from Patagonia

Science.gov (United States)

Otero, L. A.; Losno, R.; Salvador, J. O.; Journet, E.; Qu, Z.; Triquet, S.; Monna, F.; Balkanski, Y.; Bulnes, D.; Ristori, P. R.; Quel, E. J.

2013-05-01

A combined approach including ground level aerosol sampling, lidar and sunphotometer measurements is used to monitor suspended particles in the atmosphere at several sites in Patagonia. Motivated by the Puyehue volcanic eruption in June 2011 two aerosol monitoring stations with several passive and active instruments were installed in Bariloche and Comodoro Rivadavia. The main goal which is to monitor ground lifted and transported ashes and dust involving danger to civil aviation, is achieved by measuring continuously aerosol concentration at ground level and aerosol vertical distribution using lidar. In addition, starting from December 2011, continuous series of weekly accumulated aerosol concentrations at Rio Gallegos are being measured to study the impact of Patagonian dust over the open ocean on phytoplankton primary productivity and CO2 removal. These measurements are going to be coupled with LIDAR monitoring and a dust optical response models to test if aerosol extrapolation can be done from the ground to the top of the layer. Laboratory chemical analysis of the aerosols will include elemental composition, solubilisation kinetic and mineralogical determination. Expected deliverables for this study is the estimation of the amount of dust exported from Patagonia towards the South Atlantic, its chemical properties, including bioavailability simulation, from model and comparison to experimental measurements.

The Usefulness of Edible and Medicinal Fabaceae in Argentine and Chilean Patagonia: Environmental Availability and Other Sources of Supply

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Soledad Molares

2012-01-01

Full Text Available Fabaceae is of great ethnobotanical importance in indigenous and urban communities throughout the world. This work presents a revision of the use of Fabaceae as a food and/or medicinal resource in Argentine-Chilean Patagonia. It is based on a bibliographical analysis of 27 ethnobotanical sources and catalogues of regional flora. Approximately 234 wild species grow in Patagonia, mainly (60% in arid environments, whilst the remainder belong to Sub-Antarctic forest. It was found that 12.8% (30 species, mainly woody, conspicuous plants, are collected for food or medicines. Most of the species used grow in arid environments. Cultivation and purchase/barter enrich the Fabaceae offer, bringing it up to a total of 63 species. The richness of native and exotic species, and the existence of multiple strategies for obtaining these plants, indicates hybridization of knowledge and practices. Only 22% of the total species used are mentioned in bothcontexts of food and medicine, reflecting low-use complementation. This study suggests a significant ecological appearance and a high level of availability in shops and exchange networks in Patagonia, highlighting the need to consider the full set of environmental and socioeconomic factors in research related to the use and cultural importance of plants in regional contexts.

The Usefulness of Edible and Medicinal Fabaceae in Argentine and Chilean Patagonia: Environmental Availability and Other Sources of Supply

Science.gov (United States)

Molares, Soledad; Ladio, Ana

2012-01-01

Fabaceae is of great ethnobotanical importance in indigenous and urban communities throughout the world. This work presents a revision of the use of Fabaceae as a food and/or medicinal resource in Argentine-Chilean Patagonia. It is based on a bibliographical analysis of 27 ethnobotanical sources and catalogues of regional flora. Approximately 234 wild species grow in Patagonia, mainly (60%) in arid environments, whilst the remainder belong to Sub-Antarctic forest. It was found that 12.8% (30 species), mainly woody, conspicuous plants, are collected for food or medicines. Most of the species used grow in arid environments. Cultivation and purchase/barter enrich the Fabaceae offer, bringing it up to a total of 63 species. The richness of native and exotic species, and the existence of multiple strategies for obtaining these plants, indicates hybridization of knowledge and practices. Only 22% of the total species used are mentioned in bothcontexts of food and medicine, reflecting low-use complementation. This study suggests a significant ecological appearance and a high level of availability in shops and exchange networks in Patagonia, highlighting the need to consider the full set of environmental and socioeconomic factors in research related to the use and cultural importance of plants in regional contexts. PMID:22194774

A Middle Jurassic heterodontosaurid dinosaur from Patagonia and the evolution of heterodontosaurids

Science.gov (United States)

Pol, Diego; Rauhut, Oliver W. M.; Becerra, Marcos

2011-05-01

Heterodontosauridae is a morphologically divergent group of dinosaurs that has recently been interpreted as one of the most basal clades of Ornithischia. Heterodontosaurid remains were previously known from the Early Jurassic of southern Africa, but recent discoveries and studies have significantly increased the geographical and temporal range for this clade. Here, we report a new ornithischian dinosaur from the Middle Jurassic Cañadón Asfalto Formation in central Patagonia, Argentina. This new taxon, Manidens condorensis gen. et sp. nov., includes well-preserved craniomandibular and postcranial remains and represents the only diagnostic ornithischian specimen yet discovered in the Jurassic of South America so far. Derived features of its anatomy indicate that Manidens belongs to Heterodontosauridae, as the sister taxon of Heterodontosaurus and other South African heterodontosaurids. The presence of posterior dentary teeth with high crowns but lacking extensive wear facets in Manidens suggests that this form represents an intermediate stage in the development of the remarkable adaptations to herbivory described for Heterodontosaurus. The dentition of Manidens condorensis also has autapomorphies, such as asymmetrically arranged denticles in posterior teeth and a mesially projected denticle in the posteriormost teeth. At an estimated total length of 60-75 cm, Manidens furthermore confirms the small size of basal heterodontosaurids.

Estado actual del conocimiento de la familia Ceratopogonidae en la Patagonia (Diptera: Nematocera

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Gustavo R. SPINELLI

2009-01-01

Full Text Available Ceratopogonidae incluye pequeños dípteros nematocerosque crían en hábitats acuáticos o semiacuáticos. Hasta los ‘80, el conocimiento de su taxonomía en la Patagonia se hallaba limitado a la contribución de los comienzos de los ‘30 de Ingram y Macfie, sobre la base de material capturado en 1926-27, en el área del Parque Nacional Nahuel Huapi y zonas vecinasde Chile. En los últimos 25 años, se pusieron en marcha diferentes proyectos, resultando la descripción o registro de numerosos taxones para la región. Si se contabilizan los datos publicados, 102 especies habitan en la Patagonia, de las cuales 86 (84,31% son endémicas para la región. Este alto porcentaje es evidente en los bosques de Nothofagus, con 71 especies endémicas de estebioma, nueve lo son de la estepa y seis presentan registros en bosque y estepa. Datos aún no publicados concuerdan con este esquema. Diecinueve géneros están representados en la Patagonia, diez de ellos con amplia distribución,tres de distribución transantártica y seis son endémicos para el área. Para la misma, se hallan publicadas las revisiones de Forcipomyia, Atrichopogon, Borkenthelea, Macrurohelea y Paradasyhelea; se han finalizado y aún no publicado aquellas de Dasyhelea y Palpomyia, está muy avanzada la de Stilobezzia y se prevé comenzar con las de Austrohelea, Austrosphaeromias, Physohelea y Bezzia. Se calcula que estos datos no divulgados contienen al menos 55 especies todavía no descriptas. Con respecto a los aspectos biogeográficos se pueden destacar estudios que tienden a establecer relaciones entre las áreas reconocidas en esquemas biogeográficos propuestos para la región andina.

Population regulation in Magellanic penguins: what determines changes in colony size?

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Luciana M Pozzi

Full Text Available Seabirds are often studied at individual colonies, but the confounding effects of emigration and mortality processes in open populations may lead to inappropriate conclusions on the mechanisms underlying population changes. Magellanic penguin (Spheniscus magellanicus colonies of variable population sizes are distributed along the Argentine coastline. In recent decades, several population and distributional changes have occurred, with some colonies declining and others newly established or increasing. We integrated data of eight colonies scattered along ∼600 km in Northern Patagonia (from 41°26´S, 65°01´W to 45°11´S, 66°30´W, Rio Negro and Chubut provinces and conducted analysis in terms of their growth rates, production of young and of the dependence of those vital rates on colony age, size, and location. We contrasted population trends estimated from abundance data with those derived from population modeling to understand if observed growth rates were attainable under closed population scenarios. Population trends were inversely related to colony size, suggesting a density dependent growth pattern. All colonies located in the north--which were established during the last decades--increased at high rates, with the smallest, recently established colonies growing at the fastest rate. In central-southern Chubut, where colonies are the oldest, the largest breeding aggregations declined, but smaller colonies remained relatively stable. Results provided strong evidence that dispersal played a major role in driving local trends. Breeding success was higher in northern colonies, likely mediated by favorable oceanographic conditions. However, mean foraging distance and body condition of chicks at fledging were influenced by colony size. Recruitment of penguins in the northern area may have been triggered by a combination of density dependence, likely exacerbated by less favorable oceanographic conditions in the southern sector. Our results

Pasado y presente del uso de plantas silvestres con órganos subterráneos de almacenamiento comestibles en la Patagonia

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Juan J. Ochoa

2011-07-01

Full Text Available El presente trabajo es la primara aproximación acerca del papel de las plantas con órganos de almacenamiento subterráneos comestibles (POAS en la Patagonia, desde una perspectiva temporal y espacial, al integrar datos etnohistóricos y etnográficos actuales ligados al uso de las POAS. El 75 % de las 54 fuentes analizadas mencionan el uso de POAS en la alimentación humana de la Patagonia. Las POAS silvestres comestibles registradas ascienden a 51 especies, siendo mayor el conjunto de POAS con raíces comestibles. La estepa y zonas ecotonales resultaron las de mayor riqueza de POAS, probablemente vinculado a adaptaciones ecológicas de éstas a la aridez en el primer caso, como a la alta diversidad relativa que presentan los ecotonos, en el segundo. El registro etnohistórico mostró discontinuidades marcadas, siendo pocas las especies presentes por más de un siglo, destacándose la continuidad documental de A. tuberosa desde el siglo XVIII al presente, así como la incorporación reciente de especies exóticas. Las fuentes etnohistóricas revisadas y su contraste con datos etnobotánicos recientes de campo sugieren dinamismo en los patrones de utilización, que a lo largo del tiempo han llevado al abandono del uso de las POAS en la práctica alimentaria de la Patagonia. Las singularidades encontradas respecto a lo temporal y espacial pueden vincularse tanto a los conocimientos locales y específicos desarrollados a lo largo del tiempo por los habitantes de la Patagonia, como también a las circunstancias sociopolíticas y académicas de cada una de las fuentes analizadas.

Hydroclimatic conditions trigger record harmful algal bloom in western Patagonia (summer 2016)

OpenAIRE

León-Muñoz, Jorge; Urbina, Mauricio A.; Garreaud, René; Iriarte, José Luis

2018-01-01

A harmful algal bloom (HAB) of the raphidophyta alga Pseudochattonella cf. verruculosa during the 2016 austral summer (February-March) killed nearly 12% of the Chilean salmon production, causing the worst mass mortality of fish and shellfish ever recorded in the coastal waters of western Patagonia. The HAB coincided with a strong El Niño event and the positive phase of the Southern Annular Mode that altered the atmospheric circulation in southern South America and the adjacent Pacific Ocean. ...

Mineralogical association in the zone of argillic advanced alteration in a kaolin deposit of Patagonia Argentina

International Nuclear Information System (INIS)

Rainoldi, A; Oviedo, P.; Maiza, P.; Marfil, S.

2010-01-01

This work is about the mineralogical and petrological relations of the para genetic association of advanced argillic zone in the kaolin deposit in Patagonia.This study allowed to establish the sequence of events that took place in the deposit as well as the conditions under which they were generated

First paleoparasitological study of micromammal coprolites from the holocene of the Somuncurá Plateau Protected Natural Area (Patagonia Argentina).

Science.gov (United States)

Beltrame, María Ornela; Bellusci, Agustín; Andrade, Analía

2018-02-27

The Somuncurá Plateau is a Protected Natural Area located in the middle of the northern extra-Andean arid Patagonia. Inhabited by at least 20 small mammal species, is the place with the uppermost species richness in Patagonia. The aim of this study was to examine the parasite remains from micromammal coprolites collected in association with a bone sequence recovered at the east of the Somuncurá Plateau (site "Alero Las Lechuzas"). Coprolites came from the four temporal units previously defined: unit I (4790 ± 100 yrs. 14 C B.P.), unit II, unit III (7840 ± 120 yrs. 14 C B.P.) and unit IV. Each coprolite was processed, rehydrated, homogenized, processed by spontaneous sedimentation and examined using a light microscope. Coprolites and eggs were described, measured and photographed. Samples were positive for two nematode species: Helminthoxys caudatus Freitas, Lent & Almeida, 1937 (Oxyurida, Oxyuridae) and Trichuris spp. (Trichinellida: Trichuridae). This is the first paleoparasitological study developed for the Somuncurá Plateau Protected Area. Moreover, this is the first time that the genus Helminthoxys is reported from ancient times worldwide. Coprolites were attributed to the mountain cavy Microcavia australis (Rodentia, Caviidae).The presence of H. caudatus for the Middle Holocene of northern Patagonia contributes to the study of the history of the histricomorphs and pinworms relationships. Copyright © 2018 Elsevier B.V. All rights reserved.

A Middle Jurassic abelisaurid from Patagonia and the early diversification of theropod dinosaurs.

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Pol, Diego; Rauhut, Oliver W M

2012-08-22

Abelisaurids are a clade of large, bizarre predatory dinosaurs, most notable for their high, short skulls and extremely reduced forelimbs. They were common in Gondwana during the Cretaceous, but exceedingly rare in the Northern Hemisphere. The oldest definitive abelisaurids so far come from the late Early Cretaceous of South America and Africa, and the early evolutionary history of the clade is still poorly known. Here, we report a new abelisaurid from the Middle Jurassic of Patagonia, Eoabelisaurus mefi gen. et sp. nov., which predates the so far oldest known secure member of this lineage by more than 40 Myr. The almost complete skeleton reveals the earliest evolutionary stages of the distinctive features of abelisaurids, such as the modification of the forelimb, which started with a reduction of the distal elements. The find underlines the explosive radiation of theropod dinosaurs in the Middle Jurassic and indicates an unexpected diversity of ceratosaurs at that time. The apparent endemism of abelisauroids to southern Gondwana during Pangean times might be due to the presence of a large, central Gondwanan desert. This indicates that, apart from continent-scale geography, aspects such as regional geography and climate are important to reconstruct the biogeographical history of Mesozoic vertebrates.

Territorio y ganadería en la Patagonia Argentina: desertificación y rentabilidad en la Meseta Central de Santa Cruz

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Larry Andrade

2002-01-01

Full Text Available El artículo revisa brevemente las características que asume el proceso de desertificación en la Patagonia Austral, con énfasis en la provincia de Santa Cruz, Argentina. Se hacen referencias a la ocupación del territorio santacruceño por el ganado ovino, a fines del siglo XIX y con más intensidad a principios del siglo XX, y el impacto que ello conllevó, especialmente el desencadenamiento de un proceso erosivo (desertificación, producido básicamente por el pastoreo constante (sobrepastoreo del pastizal natural. También se encuentran referencias al sector ganadero y su participación en el producto bruto geográfico (PBG de Santa Cruz y, hacia el final, un análisis comparativo de la cantidad de animales que el productor estima que puede sostener en su campo y la cantidad que el Instituto Nacional de Tecnología Agropecuaria (INTA, con base en relevamientos de pastizal, calcula que podría mantener.

Investigación sobre manejo forestal a largo plazo en Patagonia Sur -Argentina: Lecciones del pasado, desafíos del presente Long-term forest management research in South Patagonia - Argentina: Lessons from the past, challenges from the present

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GUILLERMO J MARTÍNEZ-PASTUR

2010-03-01

Full Text Available Argentina ha basado su economía en la agricultura y el ganado, donde el bosque ha sido visto como un obstáculo para el desarrollo. La cosecha forestal en Patagonia Sur ha sido una actividad basada en la colonización y explotación de nuevas áreas. Esta se realiza principalmente en bosques primarios sin ningún manejo silvícola posterior. A pesar de que el manejo actual no es sustentable, la investigación científica ha definido las bases para conservar, proteger y mejorar las propuestas de manejo forestal para los bosques nativos de Patagonia Sur. Las primeras parcelas de estudio a largo plazo (1965-1966 basaron su monitoreo en parámetros económicos y estructura forestal, estableciéndose cerca de veinte parcelas en bosques fiscales de Tierra del Fuego. La mayoría fueron destruidas o discontinuadas debido a la falta de planificación del uso de la tierra, escaso interés social en la investigación, falta de compromiso de instituciones, y poca colaboración con empresas forestales. Posteriormente, un segundo grupo de nueve parcelas se estableció en Patagonia Sur (1993-2004 basado en la colaboración entre empresas privadas e instituciones nacionales. Los objetivos incluyeron parámetros económicos y ecológicos. Las parcelas se establecieron en tierras privadas conjuntamente con empresas privadas y estancieros, mediante la firma de acuerdos y proyectos de investigación. Los principales problemas encontrados fueron: falta de compromiso de las administraciones forestales, ausencia de proyectos financiados a largo plazo, y que la responsabilidad de las parcelas continúa bajo la iniciativa personal de los investigadores participantes. El estudio de las parcelas permitió: (i proponer nuevos sistemas de regeneración basados en la maximización del rendimiento y el mejoramiento del valor de conservación de los bosques manejados (e.g., retención variable y sistemas silvopastoriles, (ii determinar la factibilidad económica de aplicaci

Inter-subjectivity and Domestication in the Making of a Global Region: Territorialization of Salmon in the Chilean Patagonia.

NARCIS (Netherlands)

Blanco, Gustavo; Arce, A.M.G.; Fisher, E.F.

2016-01-01

This article examines transformations in the Chilean Patagonia, a region that has become a world leader in Salmon production for global markets. Employing ethnographic methods, this study examines the possibilities of considering inter-subjectivities in the processes of conforming important regions

Glaciers in Patagonia: Controversy and prospects

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Kargel, J. S.; Alho, P.; Buytaert, W.; Célleri, R.; Cogley, J. G.; Dussaillant, A.; Guido, Z.; Haeberli, W.; Harrison, S.; Leonard, G.; Maxwell, A.; Meier, C.; Poveda, G.; Reid, B.; Reynolds, J.; Rodríguez, C. A. Portocarrero; Romero, H.; Schneider, J.

2012-05-01

Lately, glaciers have been subjects of unceasing controversy. Current debate about planned hydroelectric facilities—a US7- to 10-billion megaproject—in a pristine glacierized area of Patagonia, Chile [Romero Toledo et al., 2009; Vince, 2010], has raised anew the matter of how glaciologists and global change experts can contribute their knowledge to civic debates on important issues. There has been greater respect for science in this controversy than in some previous debates over projects that pertain to glaciers, although valid economic motivations again could trump science and drive a solution to the energy supply problem before the associated safety and environmental problems are understood. The connection between glaciers and climate change—both anthropogenic and natural—is fundamental to glaciology and to glaciers' practical importance for water and hydropower resources, agriculture, tourism, mining, natural hazards, ecosystem conservation, and sea level [Buytaert et al., 2010; Glasser et al., 2011]. The conflict between conservation and development can be sharper in glacierized regions than almost anywhere else. Glaciers occur in spectacular natural landscapes, but they also supply prodigious exploitable meltwater.

[Outbreak of histoplasmosis in province of Neuquén, Patagonia Argentina].

Science.gov (United States)

Calanni, Liliana María; Pérez, Rufina Ana; Brasili, Susana; Schmidt, Norma Graciela; Iovannitti, Cristina Adela; Zuiani, María Fernanda; Negroni, Ricardo; Finquelievich, Jorge; Canteros, Cristina Elena

2013-01-01

In Argentina, there are no reports of autochthonous cases of histoplasmosis in the southern regions of the country. To report a histoplasmosis outbreak in Zapala town, Province of Neuquén, Patagonia Argentina. We evaluated the clinical and epidemiological characteristics of 5 patients involved in the outbreak. Environmental studies were conducted to determine the source of infection. The genetic profile of Histoplasma capsulatum strains isolated from the index case (IC) were compared with clinical isolates from Argentinean patients not related to the outbreak, using RAPD-PCR with primers 1281-1283. The patients were residents of Zapala, and had not visited other geographical areas before. All patients had an influenza-like syndrome, and X-ray revealed disseminated micronodular images throughout the lung parenchyma. The IC needed specific antifungal therapy; the remaining 4 patients had mild symptoms, and did not require therapy. All of them had a good clinical outcome. Strains of H. capsulatum isolated from blood culture and lung biopsy of the IC showed a genetic profile different from other strains analyzed. The presence of the fungus in the environment was demonstrated by the detection of anti-Histoplasma antibodies in BALB/c mice inoculated with soil obtained in a culvert where workers had dug up earth after a landslide. This outbreak suggests the histoplasmosis endemic area is under the 38° S parallel. Patients from Neuquén, Patagonia Argentina, with compatible symptoms of histoplasmosis should be tested, regardless of their travel or exposure history. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Respiratory function in voluntary participating Patagonia sea lions in sternal recumbency

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Andreas Fahlman

2016-11-01

Full Text Available We measured esophageal pressures (n=4, respiratory flow rates (n=5, and expired O2 and CO2 (n=4 in five adult Patagonia sea lions (Otaria flavescens, body mass range 94.3-286.0 kg during voluntary breaths while laying down. The data were used to estimate the dynamic specific lung compliance (sCL, cmH2O-1, the O2 consumption rate (VO2 and CO2 production rates (VCO2 during rest. Our results indicate that the resting tidal volume in Patagonia sea lions is approximately 47-73% of the estimated total lung capacity. The esophageal pressures indicated that expiration is passive during voluntary breaths. The average sCL of dolphins was 0.41±0.11 cmH2O−1, which is similar to those measured in anesthetized sea lions and awake cetaceans, and significantly higher as compared with humans (0.08 cmH2O−1. The average estimated and using breath-by-breath respirometry were 1.023 ± 0.327 L O2 min-1 (range: 0.695-1.514 L O2 min−1 and 0.777 ± 0.318 L CO2 min-1, (range: 0.510-1.235 L CO2 min-1, respectively, which is similar to previously published metabolic measurements from California and Steller sea lions using conventional flow-through respirometry. Our data provide end-tidal gas composition and provide novel data for respiratory physiology in pinnpeds, which may be important for clinical medicine and conservation efforts.

Nacionalismo territorialista en textos escolares: representaciones de la Patagonia en la dictadura militar argentina (1966-1983 Territorialist nationalism in school textbooks: representations of Patagonia in Argentinian military dictatorship (1966-1983

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Jesús Jaramillo

2012-03-01

Full Text Available Los textos escolares desde hace tiempo se han constituido en una de las fuentes primarias para el campo de la Historia de la Educación en tanto son instrumentos de socialización formal básica. Sea considerado registro escrito editorial, herramienta didáctica o registro de memoria escolar, los textos escolares instituyen - y, en ocasiones, eternizan - concepciones e intereses reflejados en sus contenidos "oficiales". Investigaciones recientes en la búsqueda de la realidad escolar han enfatizado la importancia de los mismos en la construcción de las identidades nacionales, pero también de las identidades de grupos socio-culturales, socio-étnicos y regionales. Este artículo, a partir de una indagación historiográfica sobre libros de lectura, intenta reconstruir las diferentes tramas discursivas textuales e iconográficas en que ha sido representada la Patagonia durante los periodos dictatoriales argentinos 1966-1973 y 1976-1983, en escuelas primarias de Río Negro y Neuquén. En principio, puede advertirse un conjunto de relatos de la Patagonia y sus habitantes sobre la base de tres núcleos de sentido: el de territorio indígena, desierto e inculto; el de promisión para el progreso y el turismo; y el de soberanía nacional. A través de sus argumentos daremos cuenta que los libros escolares de edición nacional con rasgos eminentemente políticos pero también étnicos y raciales fueron medios de formación y, sobre todo, dispositivos que coadyuvaron a la conformación de una línea ideológica, política y pedagógica propia del nacionalismo católico militar.School textbooks have long been taken as one of the primary sources for the field of the History of Education, since they are instruments of basic formal socializing. Either as editorial written records, as didactic tools, or as records of school memory, school textbooks institute - and sometimes crystallize - conceptions and interests reflected in their "official" contents

Evaluation of an indirect elisa for the diagnosis of bovine brucellosis in Patagonia, Argentina

International Nuclear Information System (INIS)

Uzal, F.A.; Carrasco, E.A.; Robles, C.A.; Echaide, S.

1998-01-01

Control and eradication of bovine brucellosis is usually based on the serological detection of antibodies. In Argentina, the Rose Bengal test (RB) and the Buffered Plate antigen test (BPA) are the two screening test officially recognized, while the 2-mercaptoethanol test (2ME) and the Tube Agglutination test (SAT) are the confirmatory assays currently in use. In order to improve the serological diagnosis of bovine brucellosis in Patagonia, Argentina, an indirect ELISA kit produced by the Joint FAO/IAEA Division was evaluated. Sera from negative non-vaccinated, negative but vaccinated and positive animals were tested by all the above techniques. The specificity of the I-ELISA (99.6% and 99.7%) was similar to that of the BPA, RB, 2ME and Complement Fixation test (CF) when used to test sera from non-vaccinated, negative and vaccinated, negative animals, respectively. The sensitivity of the I-ELISA (98%) was higher than the BPA test (96%) and the CF test (95,2%). The I-ELISA kit evaluated in this study was thought to be a valuable tool for the diagnosis of bovine brucellosis in Patagonia region where little epidemiological information is available about this disease and where large numbers of sera should be tested to obtain such information. (author)

Diplodon shells from Northwest Patagonia as continental proxy archives: Oxygen isotopic results and sclerochronological analyses

Science.gov (United States)

Soldati, A. L.; Beierlein, L.; Jacob, D. E.

2009-04-01

Freshwater mussels of the genus Diplodon (Bivalvia, Hyriidae) are the most abundant bivalve (today and in the past) in freshwater bodies at both sides of the South-Andean Cordillera. There are about 25 different Diplodon genera in Argentina and Chile that could be assigned almost completely to the species Diplodon chilensis (Gray, 1828) and two subspecies: D. ch. chilensis and D. ch. patagonicus; this latter species is found in Argentina between Mendoza (32˚ 52' S; 68˚ 51' W) and Chubut (45˚ 51' S; 67˚ 28' W), including the lakes and rivers of the target area, the Nahuel Huapi National Park (Castellanos, 1960). Despite their wide geographic distribution, Diplodon species have only rarely been used as climate archives in the southern hemisphere. Kaandorp et al. (2005) demonstrated for Diplodon longulus (Conrad 1874) collected from the Peruvian Amazonas that oxygen isotopic patterns in the shells could be used in order to reconstruct the precipitation regime and dry/wet seasonal of the monsoonal system in Amazonia. Although this study demonstrated the potential of Diplodon in climatological and ecological reconstructions in the southern hemisphere, as of yet, no systematic study of Diplodon as a multi-proxy archive has been undertaken for the Patagonian region. In this work we present sclerochronological analyses supported by ^18Oshell in recent mussel of Diplodon chilensis patagonicus (D'Orbigny, 1835) collected at Laguna El Trébol (42°S-71°W, Patagonia Argentina), one of the best studied water bodies in the region for paleoclimate analysis. Water temperature was measured every six hours for one year using a temperature sensor (Starmon mini®) placed at 5m depth in the lake, close to a mussel bank. Additionally, ^18Owater was measured monthly for the same time range.g^18Oshell values obtained by micro-milling at high spatial resolution in the growth increments of three Diplodon shells were compared to these records, and to air temperature and

PLANTAS AROMÁTICAS CON ÓRGANOS SUBTERRÁNEOS DE IMPORTANCIA CULTURAL EN LA PATAGONIA ARGENTINA: UNA APROXIMACIÓN A SUS USOS DESDE LA ETNOBOTÁNICA, LA PERCEPCIÓN SENSORIAL Y LA ANATOMÍA

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Soledad Molares

2012-01-01

Full Text Available Se analiza la etnobotánica y anatomía de cinco especies aromáticas de uso medicinal y/o comestible altamente valoradas en la Patagonia argentina: Valeriana clarionifolia, V. carnosa (Valerianaceae, Azorella monantha, Osmorhiza chilensis y Eryngium paniculatum (Apiaceae. El principal énfasis ha sido la caracterización de las estructuras secretoras de sus órganos subterráneos y su posible vinculación con las percepciones sensoriales y usos dados por los pobladores. El trabajo etnobotánico se realizó en dos comunidades indígenas Mapuches de la Provincia de Neuquén y en otras dos de la Provincia de Chubut, con un total de 53 entrevistas. El trabajo anatómico consistió en la observación estructural y ultraestructural de las estructuras secretoras. Los informantes indicaron que E. paniculatum es principalmente usada para tratar trastornos digestivos y hepáticos, O. chilensis para problemas de la visión y A. monantha como urinaria y antitusiva; además los órganos subterráneos de estas tres especiesse consumen crudos y/o cocidos. Las especies de Valeriana son usadas principalmente como analgésicas, digestivas, antitusivas y en síndromes culturales. El sabor y el aroma son las principales propiedades sensoriales usadas para reconocer y usar las especies de Valeriana y O. chilensis. A. monantha y E. paniculatum son reconocidas por sus características morfológicas, aunque también se valoranpor su sabor y aroma. Las observaciones microscópicas revelan la presencia de cavidades secretoras esquizógenas en O. chilensis, E. paniculatum y A. monantha y abundante presencia de almidón. En las especies de Valeriana se observa la peridermiscon elevado contenido de aceites esenciales como gotas. Se concluye que estas cinco especies poseen atributos organolépticos originados en estructuras anatómicas especializadas, los que en parte explicarían sus empleos alimenticios y/o medicinales.

Helminth communities of two populations of Myotis chiloensis (Chiroptera: Vespertilionidae from Argentinean Patagonia

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Antonella C. Falconaro

2018-04-01

Full Text Available Most of the studies on chiropteran endoparasites in Argentina come from the Central and Northeast regions of the country, and there is only one parasitological study of bats from the Argentinean Patagonia. The aim of this study is to describe the helminth fauna of 42 Myotis chiloensis, comparing the composition and the structure of the endoparasite communities between two populations, inhabiting different environments in Andean humid forest and the ecotone between forest and Patagonian steppe. A total of 697 helminths were recovered from 33 bats: five species of trematodes, Ochoterenatrema sp., Paralecithodendrium sp., Parabascus limatulus, Parabascus sp., and Postorchigenes cf. joannae, two species of cestodes, Vampirolepis sp. 1 and Vampirolepis sp. 2, and three species of nematodes, Allintoshius baudi, Physaloptera sp., and Physocephalus sp. All the helminths, but Physocephalus sp., were recovered from the small and large intestine. This is the first survey of M. chiloensis’ helminth fauna. All the species, but A. baudi, represent new records of helminths in Patagonian bats. There were differences of parasite species richness between localities and both bat populations share almost half of the endoparasite species. Different preferences for intestinal regions were found for three species of trematodes in the bats from the site in the humid forest. Myotis chiloensis serves as both a definitive and intermediate host for endoparasites in the Patagonian ecosystem. Keywords: Bats, Parasites, South America

A method for estimation of hydrological sensibility applied in Golfo San Jorge basin. Province of Chubut. Argentina; Un metodo para estimar la sensibilidad hidrologica aplicado en la cuenca del Golfo San Jorge. Provincia de Chubut. Argentina

Energy Technology Data Exchange (ETDEWEB)

Hernandez, M. A.; Scatizza, C.; Rojo, M.; Preiato, S. A.; Hernandez, L.

2009-07-01

A method developed and used in an area of Chubut Province is described. The object of the method is to determine the underground and surficial hydrological sensitivity in order to select the site of petroleum facilities with the least possible environmental hydric risk. It is based on the conjunction of the GOD method used to assess the intrinsic aquifer vulnerability (original version) and the proposed La Plata Method (MLP) for the surficial hydrological sensitivity. The latter method assigns numerical values based on landforms (positive and negative), slope percent and seasonality of the water regime, using a complexive range scale from zero to one. The Surficial Sensitivity factor results from the average of the three indicators and includes five categories, from low to extreme values. For a global coverage in the underground and surficial terrestrial arches (geo environmental map) it is proposed to compare the GOD values with those of the MLP method using a GIS, through the mathematical overlapping of two raster layers (map algebra) in each map pixel. In addition to the cartographic display, attribute tables can be used to estimate the environmental pollution in soils and waters, existing infrastructure and location of new facilities and drillings. The Arc Map 9.1 program was used due to its capacity for a permanent and quasi-automatic updating of thematic mapping. The map corresponding to Cerro for the initial position 2007 is presented as an example. (Author) 6 refs.

Rainforest conifers of Eocene Patagonia: attached cones and foliage of the extant Southeast Asian and Australasian genus Dacrycarpus (Podocarpaceae).

Science.gov (United States)

Wilf, Peter

2012-03-01

Eocene caldera-lake beds at Laguna del Hunco (LH, ca. 52.2 Ma) and Río Pichileufú (RP, ca. 47.7 Ma) in Argentine Patagonia provide copious information about the biological history of Gondwana. Several plant genera from these sites are known as fossils from southern Australia and New Zealand and survive only in Australasian rainforests. The potential presence of Dacrycarpus (Podocarpaceae) holds considerable interest due to its extensive foliage-fossil record in Gondwana, its remarkably broad modern distribution in Southeast Asian and Australasian rainforests, its high physiological moisture requirements, and its bird-dispersed seeds. However, the unique seed cones that firmly diagnose Dacrycarpus were not previously known from the fossil record. I describe and interpret fertile (LH) and vegetative (LH and RP) material of Dacrycarpus and present a nomenclatural revision for fossil Dacrycarpus from South America. Dacrycarpus puertae sp. nov. is the first fossil occurrence of the unusual seed cones that typify living Dacrycarpus, attached to characteristic foliage, and of attached Dacrycarpus pollen cones and foliage. Dacrycarpus puertae is indistinguishable from living D. imbricatus (montane, Burma to Fiji). Dacrycarpus chilensis (Engelhardt) comb. nov. is proposed for Eocene vegetative material from Chile. Modern-aspect Dacrycarpus was present in Eocene Patagonia, demonstrating an astonishingly wide-ranging paleogeographic history and implying a long evolutionary association with bird dispersers. Dacrycarpus puertae provides the first significant Asian link for Eocene Patagonian floras, strengthens the biogeographic connections from Patagonia to Australasia across Antarctica during the warm Eocene, and indicates high-rainfall paleoenvironments.

Cerro Bombero: registro de Hippidion saldiasi Roth, 1899 (Equidae, Perissodactyla en el Holoceno temprano de Patagonia (Santa Cruz, Argentina

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Alberdi, M. T.

2008-06-01

Full Text Available A new record of Hippidion saldiasi with new radiocarbon data referred to early Holocene (8,850 ± 80 year C-14 B.P of Patagonia is reported. Both its peculiar geographic location in a scarcely prospected zone and its radiocarbon age, provide new elements to discuss the previous hypotheses about the extinction of the horses and its relations with the human beings that inhabited the different environments of South America.Presentamos un nuevo registro de Hippidion saldiasi con datación radiocarbónica directa correspondiente al Holoceno temprano de Patagonia (8.850 ± 80 años C-14 AP. Su particular ubicación temporal y geográfica en una zona poco estudiada hasta ahora y su registro reciente, aportan nuevos elementos para discutir las hipótesis previas sobre la extinción de los caballos y su relación con los grupos humanos que colonizaron los diferentes ambientes de América del Sur.

Conflictos ecoterritoriales transfronterizos y megaproyectos extractivistas en cuencas compartidas de la Patagonia; Conflitos ecoterritoriais transfronteiriços e megaprojetos extrativistas nas bacias da Patagônia; Cross-border Eco-territorial Conflicts and Extractivist Megaprojects in the Patagonia River Basins

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Bárbara Jerez Henríquez

2015-01-01

Full Text Available Resumen: Las cuencas transfronterizas de la Patagonia Andina argentino- chilena en los útimos 15 años se ha convertido en un espacio transnacional en el que aterrizan megaproyectos de minería y represas hidroeléctricas que conllevan importantes impactos en los ecosistemas, economías y culturas locales, como parte de una tendencia en América Latina orientada al avance de las territorialidades extractivistas hacia zonas fronterizas que además significa transgredir marcos legales previos para el manejo de cuencas compartidas. En ese contexto emergen fuertes procesos de resistencia desde diversas narrativas que en su conjunto reivindican otras territorialidades en estas cuencas abarcando escalas locales y transfronterizas que plantean nuevos debates y desafíos para discutir los conflictos ecoterritoriales que emergen en zonas de fronteras.     Palabras clave: extractivismo, cuencas, fronteras, territorialidades, Patagonia.       Resumo: As bacias transfronteiriças da Patagônia Andina Argentino-chilena nos últimos 15 anos se converteram em um espaço transnacional em que aterrissam mega-projetos de mineração e represas hidroelétricas que conduzem importantes impactos nos ecossistemas, economias e culturas locais, como parte de uma tendência na América Latina de avanço das territorialidades extrativistas em direção a zonas fronteiriças que, além de tudo, significam transgredir marcos legais para o manejo de bacias divididas. Nesse       contextos emergem fortes processos de resistência desde diversas narrativas que em seu conjunto reivindicam outras territorialidades nestas bacias cobrindo escalas locais e transfronteiriças que colocam novos debates e desafios para se discutir os conflitos ecoterritoriais que emergem nas zonas de fronteira.     Palavras-chave: extrativismo, bacias, fronteiras, territorialidade, Patagônia.       Abstract: The cross-border river basins of the Argentine-Chilean Andean Patagonia have

De Patagonia a Budapest: caminos europeos de fósiles santacrucenses (1845-1956)

OpenAIRE

Vizcaíno, Sergio Fabián; Bargo, M. Susana

2013-01-01

A fines del siglo XIX y principios del XX, acicateados por los descubrimientos de los hermanos Ameghino, los paleontólogos evolucionistas de América del Norte y Europa posaron sus ojos en los mamíferos fósiles de Patagonia. Mientras los primeros organizaron expediciones, los europeos se valieron mayormente de otras formas comunes en la época para hacer colecciones de historia natural, como el intercambio y la compra. En el viejo continente, el devenir de los fósiles patagónicos no escapó a la...

Especies forestales promisorias para la diversificación de forestaciones en la Patagonia Argentina

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Godoy, María Marcela; Defossé, Guillermo E; Thren, Martin

2007-01-01

En el oeste de la Patagonia argentina existen aproximadamente 70 mil hectáreas forestadas, de las cuales el 80% corresponde a Pinus ponderosa y el resto a Pseudotsuga menziesii y Pinus contorta. Con el objetivo de evitar esta tendencia hacia los monocultivos con sus consecuencias ecológicas y sanitarias desfavorables, surge la necesidad de evaluar la posibilidad de cultivar otras especies forestales que permitan la diversificación de las actuales forestaciones. En este trabajo se analizaron p...

A 17-year Record of Meteorological Observations Across the Gran Campo Nevado Ice Cap in Southern Patagonia, Chile, Related to Synoptic Weather Types and Climate Modes

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Stephanie S. Weidemann

2018-05-01

Full Text Available The network of long-term meteorological observations in Southernmost Patagonia is still sparse but crucial to improve our understanding of climatic variability, in particular in the more elevated and partially glaciated Southernmost Andes. Here we present a unique 17-year meteorological record (2000–2016 of four automatic weather stations (AWS across the Gran Campo Nevado Ice Cap (53°S in the Southernmost Andes (Chile and the conventional weather station Jorge Schythe of the Instituto de la Patagonia in Punta Arenas for comparison. We revisit the relationship between in situ observations and large-scale climate models as well as mesoscale weather patterns. For this purpose, a 37-year record of ERA Interim Reanalysis data has been used to compute a weather type classification based on a hierarchical correlation-based leader algorithm. The orographic perturbation on the predominantly westerly airflow determines the hydroclimatic response across the mountain range, leading to significant west-east gradients of precipitation, air temperature and humidity. Annual precipitation sums heavily drop within only tens of kilometers from ~7,500 mm a−1 to less than 800 mm a−1. The occurrence of high precipitation events of up to 620 mm in 5 days and wet spells of up to 61 consecutive days underscore the year-around wet conditions in the Southernmost Andes. Given the strong link between large-scale circulation and orographically controlled precipitation, the synoptic-scale weather conditions largely determine the precipitation and temperature variability on all time scales. Major synoptic weather types with distinct low-pressure cells in the Weddell Sea or Bellingshausen Sea, causing a prevailing southwesterly, northwesterly or westerly airflow, determine the weather conditions in Southernmost Patagonia during 68% of the year. At Gran Campo Nevado, more than 80% of extreme precipitation events occur during the persistence of these weather types. The

Chronological study of the pre-jurassic basement rocks of southern Patagonia

International Nuclear Information System (INIS)

Pankhurst, R.J; Rapela, C.W; Loske, W.P; Fanning, C.M

2001-01-01

Southern Patagonia east of the Andes was the site of extensive rhyolite volcanism during the Jurassic rifting of Gondwana and subsequent shallow marine basin formation during the Cretaceous. Thus exposures of pre-Jurassic basement are extremely sparse. Nevertheless, extraction of the maximum amount of information from these scattered outcrops of granite and metamorphic rocks is crucial to assessment of the Palaeozoic and earliest Mesozoic history and crustal structure of the Pacific margin of the supercontinent. In particular, the identification and possible correlation of early terrane accretion on this margin depends on comparison of pre-Jurassic igneous and metamorphic events with adjacent areas. This is a preliminary report on work now in progress to this end (au)

Sweet cherries from the end of the world: options and constraints for fruit production systems in South Patagonia, Argentina

NARCIS (Netherlands)

Cittadini, E.D.

2007-01-01

In South Patagonia, development of the fruit production sector has been almost exclusively based on the production of sweet cherry, with an area increase from 176 ha in 1997 to 578 ha at the end of 2006. These orchards are designed as intensive systems and oriented to export markets. Even though

Tithonian age of dinosaur fossils in central Patagonian, Chile: U-Pb SHRIMP geochronology

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Suárez, Manuel; De La Cruz, Rita; Fanning, Mark; Novas, Fernando; Salgado, Leonardo

2016-11-01

Three Tithonian concordant U-Pb SHRIMP zircon ages of 148.7 ± 1.4, 147.9 ± 1.5 and 147.0 ± 1.0 from tuffs intercalated in a clastic sedimentary succession with exceptional dinosaur bones including the new taxon Chilesaurus diegosuarezi gen. et sp. nov. exposed in central Chilean Patagonia (ca. 46°30'S) are reported herein. The fossiliferous beds accumulated in a synvolcanic fan delta reaching a shallow marine basin as indicated by glauconite present in some of the beds, and coeval with the beginning of the transgression of the Aysén Basin.

Madera de Pinus ponderosa en Patagonia Argentina : Jornada Forestal Tecnológica

OpenAIRE

Refort, María Mercedes; Keil, Gabriel Darío; Spavento, Elena

2013-01-01

El día 15 de noviembre de 2012 se realizó en el Edificio de Bosques de la Facultad de Ciencias Agrarias y Forestales de la UNLP, la Primera Jornada Tecnológica sobre Madera de Pinus ponderosa en Patagonia Argentina, destinadas a profesionales de diferentes áreas, estudiantes, investigadores y docentes. Las Jornadas fueron organizadas por el Laboratorio de Investigaciones en Madera (LIMAD) y la Secretaría de Investigaciones de la Facultad de Ciencias Agrarias y Forestales, UNLP y auspiciadas p...

Mercury in lichens of Nahuel Huapi National Park, Patagonia, Argentina

International Nuclear Information System (INIS)

Ribeiro Guevara, S.; Bubach, D.; Arribere, M.; Nacional de Cuyo Universidad, Bariloche

2004-01-01

Mercury and other elements of interest are determined in lichens collected in Nahuel Huapi National Park, Northern Patagonia, Argentina. Pooled samples are analyzed by instrumental neutron activation analysis. Mercury contents in Usnea sp. collected from undisturbed sites range from 0.0558 ± 0.0083 to 1.38 ± 0.18 μg x g -1 . Other potential pollutants are identified by the analysis of Usnea sp. samples, namely Sb, As, Br, Zn, and Se. Previous experiments with foliose and fruticose lichens are also discussed. The analysis of mercury contents of foliose lichens sampled from urban and periurban sites of Bariloche city, and from undisturbed regions, demonstrate that the atmosphere of Bariloche city is enriched in mercury compared to the surroundings. The result is confirmed by transplantation experiments from undisturbed zones to urban sites. (author)

Capacity building for freshwater insect studies in northern Patagonia, Argentina: DARWIN Initiative programme

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Stephen J. BROOKS

2009-01-01

Full Text Available Este proyecto fue financiado durante un período de tres años, desde septiembre de 2006 a través de la Iniciativa Darwin del gobierno Británico. El objetivo de este trabajo es el estudio de los insectos acuáticos del Parque Nacional Nahuel Huapi (PNNHP, Patagonia, Argentina. El parque incluye una gran variedad de hábitats que comprenden arroyos, ríos y lagos los cuales se distribuyen desde el bosque siempreverde frío, hasta la zona árida de estepa. Todo el material será identificado y depositado en las colecciones del Museo La Plata y el Museo de Historia Natural de Londres. Los fondos de la Iniciativa Darwin han sido utilizados para equipar un laboratorio de biodiversidad en las oficinas del PNNHP en Bariloche y la estación de investigación en Puerto Blest. Toda la información de los insectos acuáticos y las distintas formaciones vegetales donde éstos se han encontrado, se incluirá en una base de datos (la primera de su tipo en Patagonia que utilizará la metodología GIS para analizar patrones de distribución de las especies en el parque. En estos momentos se están produciendo varias guías de campo para identificar los insectos acuáticos del PNNHP. Es nuestro deseo que los resultados obtenidos en este proyecto, contribuyan a la conservación de los sistemas acuáticos en Argentina y América del Sur

Domestication and human demographic history in South America.

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Perez, S Ivan; Postillone, María Bárbara; Rindel, Diego

2017-05-01

The early groups of hunter-gatherers who peopled South America faced significant ecological changes in their trophic niche for a relatively short period after the initial peopling. In particular, the incorporation of cultigens during the Holocene led to a wider trophic niche and probably to an increased carrying capacity of the environment. Here, we study the relationship between the incorporation of domestic resources during the Holocene and the demographic dynamics of human populations at a regional scale in South America. We employ mitochondrial DNA (mtDNA), radiocarbon data and Bayesian methods to estimate differences in population size, human occupation and explore the demographic changes of human populations in three regions (i.e., South-Central Andes, Northwest, and South Patagonia). We also use archaeological evidence to infer the main diet changes in these regions. The absolute population size during the later Late Holocene was fifteen times larger in the South-Central Andes than in Northwest Patagonia, and two times larger in the latter region than in South Patagonia. The South-Central Andes display the earlier and more abrupt population growth, beginning about 9000 years BP, whereas Northwest Patagonia exhibits a more slow growth, beginning about 7000-7500 years BP. South Patagonia represents a later and slower population increase. In this work we uncovered a well-supported pattern of the demographic change in the populations from South-Central Andes and Patagonia, obtained on the basis of different data and quantitative approaches, which suggests that the incorporation of domestic resources was paramount for the demographic expansion of these populations during the Holocene. © 2017 Wiley Periodicals, Inc.

Saccharomyces eubayanus and Saccharomyces uvarum associated with the fermentation of Araucaria araucana seeds in Patagonia.

Science.gov (United States)

Rodríguez, M Eugenia; Pérez-Través, Laura; Sangorrín, Marcela P; Barrio, Eladio; Lopes, Christian A

2014-09-01

Mudai is a traditional fermented beverage, made from the seeds of the Araucaria araucana tree by Mapuche communities. The main goal of the present study was to identify and characterize the yeast microbiota responsible of Mudai fermentation as well as from A. araucana seeds and bark from different locations in Northern Patagonia. Only Hanseniaspora uvarum and a commercial bakery strain of Saccharomyces cerevisiae were isolated from Mudai and all Saccharomyces isolates recovered from A. araucana seed and bark samples belonged to the cryotolerant species Saccharomyces eubayanus and Saccharomyces uvarum. These two species were already reported in Nothofagus trees from Patagonia; however, this is the first time that they were isolated from A. araucana, which extends their ecological distribution. The presence of these species in A. araucana seeds and bark samples, led us to postulate a potential role for them as the original yeasts responsible for the elaboration of Mudai before the introduction of commercial S. cerevisiae cultures. The molecular and genetic characterization of the S. uvarum and S. eubayanus isolates and their comparison with European S. uvarum strains and S. eubayanus hybrids (S. bayanus and S. pastorianus), allowed their ecology and evolution us to be examined. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

La proyección colonial de Chile a la Patagonia Insular en el siglo XVIII

OpenAIRE

Urbina Carrasco, María Ximena

2011-01-01

In this article, the geopolitical consequences of the shipwreck of the English frigate Wager and the landfall of the ship Anna into the coasts of the Western Insular Patagonia in 1741 are presented, which were part of the fleet of George Anson. The news reporting the English presence in the deserted and unknown insular and coastal territory southernmost Chiloé, and which had disseminated towards the end of the continent, promoted the deployment of different actions tending to make presence no...

Relaciones polen-vegetación de algunos taxa de la estepa patagónica (Argentina Pollen-vegetation relationships of some taxa from the Patagonian steppe (Argentina

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LIDIA S. BURRY

2001-06-01

Full Text Available La aplicación de un análisis de regresión lineal simple a datos de lluvia de polen y de vegetación, en una zona de la Patagonia (Provincia de Chubut, Argentina permitió relacionar cuantitativamente los porcentajes de lluvia polínica y de cobertura de la vegetación para los taxa Poaceae, Papilionoideae, tipo Senecio y Mulinum spinosum. Se obtuvo un buen ajuste de las rectas de regresión para cada uno de los taxa considerados, con coeficientes de correlación r de Pearson altos para M. spinosum (0,82 y tipo Senecio (0,81 y coeficientes algo menores en el caso de Poaceae (0,66 y Papilionoideae (0,61. Estas regresiones permitieron inferir la presencia o ausencia de polen regional y el valor predictivo de la presencia de polen en ausencia de la vegetación que lo produce. Al respecto, la lluvia de polen estudiada incluye el aporte regional (excepto Papilionoideae aun cuando M. spinosum tiene una baja contribución. Esta sobrerrepresentación es atribuible al transporte de larga distancia, a través de los vientos que provienen del oeste. Estas relaciones cuantitativas nos permitirán extrapolar cambios vegetacionales pasados en estos taxa a partir de espectros de polen fósil para el área de estudioThe use of simple linear regression to data of pollen rain and vegetation cover in Patagonia (Province of Chubut, Argentina allowed us to develop quantitative relationships between modern pollen rain perecentages and vegetation cover for the taxa Poaceae, Papilionoideae, Senecio type, and Mulinum spinosum. The analysis revealed a good fit of data to regression lines for all taxa, with high Pearson r coefficient values in the case of M. spinosum (0.82 and Senecio type (0.81, and somewhat lower values in the case of Poaceae (0.66 and Papilionoideae (0.61. These regressions allowed us to infer the presence or absence of regional pollen and predict the quantity of pollen in the absence of the vegetation producing it. In this regard, the studied pollen

Alien invasions and the game of hide and seek in Patagonia.

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Martin Lindegren

Full Text Available The introduction, establishment and spread of alien species is a major threat to biodiversity and the provision of ecosystem services for human wellbeing. In order to reduce further loss of biodiversity and maintain productive and sustainable ecosystems, understanding the ecological mechanisms underlying species invasions and avoiding potentially harmful effects on native communities is urgently needed, but largely lacking. We here demonstrate, by means of hydroacoustics and advanced spatial modelling, how native fish species as a result of previous exposure to native predators may successfully respond to invasive novel predators through a complicated game of hide and seek, minimizing spatio-temporal overlap with predators, and potentially facilitating coexistence between native prey species (Galaxiids and introduced novel predators (Salmonids in a deep Andean lake, Patagonia.

HOTELES DE TRELEW (CHUBUT, ARGENTINA HACIA EL DESARROLLO SUSTENTABLE DE LA ACTIVIDAD CON RESPONSABILIDAD SOCIAL

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Ana M. Gómez

2008-12-01

Full Text Available El trabajo se enmarca en el Proyecto de Investigación “Hotelería Sustentable en la Ciudad de Trelew, Provincia del Chubut, República Argentina” cuyo objetivo general es diseñar un sistema de Administración para la hotelería de Trelew, que viabilice su gestión en el marco del desarrollo sustentable de la actividad hotelera. Como hipótesis de trabajo se supuso que la hotelería estaría en condiciones de tener una gestión sustentable cuando demostrara poseer una cultura empresarial dirigida al desarrollo sustentable, llevando a cabo una actividad económica viable, con equidad social y respeto a los recursos naturales, culturales y de biodiversidad; es decir, con Responsabilidad Social Empresarial. Combinando la metodología de encuesta con la de entrevista en profundidad se abordó a la totalidad de los propietarios/administradores de los hoteles de la ciudad, sumando un total de diez. En la entrevista, además de recabar valiosa información por parte de los entrevistados, se les proporcionó un cuestionario que contenía preguntas pertinentes para la elaboración de indicadores de impacto. De los entregados fueron devueltos nueve cuestionarios, redefiniéndose de esta manera el universo a analizar. Los datos fueron trabajados en primer lugar en forma unidimensional, para detectar las categorías de mayor frecuencia de respuesta y se rescataron los resultados más significativos. Luego, dada la cantidad de indicadores involucrados (alrededor de 70 preguntas en el cuestionario, se hizo un estudio multidimensional con una técnica de escalonamiento multidimensional: la de componentes principales. Con este procedimiento estadístico se logra un índice de nivel de compromiso hacia el desarrollo sustentable de la actividad, que permite realizar un análisis comparativo entre los hoteles participantes. Por otra parte, la Provincia del Chubut categoriza a los hoteles desde 1980 de acuerdo a la infraestructura y comodidades ofrecidas. Hoy

Respuesta dietaria de tres rapaces frente a una presa introducida en Patagonia Dietary response of three raptor species to an introduced prey in Patagonia

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ANA L. MONSERRAT

2005-09-01

Full Text Available Los depredadores de marcada respuesta funcional pueden poseer la capacidad de estabilizar las poblaciones de sus presas, lo cual es destacable en el caso de presas introducidas, que suelen causar impactos negativos en los ecosistemas nativos y las actividades agropecuarias. La situación actual de la Patagonia es crítica respecto a la introducción de especies. Estudios previos indican que los depredadores nativos exhiben un cambio general en sus dietas debido a la introducción de presas exóticas que están reemplazando a sus presas originales. Determinamos los hábitos alimenticios del águila (Geranoaetus melanoluecus, el búho magallánico (Bubo magellanicus y el aguilucho común (Buteo polyosoma, tres de las principales aves depredadoras de la liebre europea (Lepus europaeus, introducida en el noroeste de Patagonia. Para esto analizamos 321, 115 y 78 egagrópilas de águila, búho y aguilucho respectivamente. Evaluamos las respuestas funcionales a la densidad de liebre europea y comparamos las dietas entre sitios diferentes. Las principales presas del aguilucho y del búho fueron los roedores sigmodontinos y en segundo lugar los tuco-tucos (Ctenomys spp.. El águila consumió principalmente liebres y en segundo lugar tuco-tucos, presentando una respuesta funcional significativa para la presa introducida. La dieta de este rapaz fue diferente entre sitios con alta y baja densidad de liebres. Para los otros dos rapaces no encontramos una respuesta funcional significativa para la liebre europea, pero la dieta del aguilucho varió en función del sitio geográfico. Concluimos que tanto el águila mora como el aguilucho se alimentan de manera generalista, siendo el búho el único de los tres rapaces con tendencia especialista sobre pequeños roedores. Por otra parte, la variación de la dieta del águila en función de la densidad de liebre europea le brinda el potencial de contribuir a la regulación de las poblaciones de la misma

Cultural Transmission of Traditional Knowledge in two populations of North-western Patagonia

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Lozada Mariana

2008-12-01

Full Text Available Abstract Background In the present study we have investigated the cultural transmission of two types of traditional plant knowledge in two communities of North-western Patagonia, Argentina. In the Pilcaniyeu community, we studied the transmission of traditional knowledge related to horticultural practices in home-gardens, greenhouses and gardens; while in the community of Cuyin Manzano, we studied wild plant gathering customs. Methods Ethnobotanical fieldwork was conducted by means of semi-structured interviews, in which we investigated which plants are used, at what life history phase was learned, modes of transmission and who the principal transmitters were in childhood and adulthood. In both communities, each of this three aspects related to cultural transmission were categorized and the frequencies of each category were obtained. The total number of species recorded in each community was also calculated. Frequencies were analyzed with the Chi-square test of independence. Results and discussion In both communities, transmission of traditional plant knowledge begins at an early age, as a family custom, in which women play a predominant role. Wild plant use and horticultural knowledge continue to be learned during adulthood. This was particularly registered associated with horticultural learning, which receives greater influence from extension agents who are introducing new practices and technology. This outside influence, which implies novelty, could imply syncretism but also traditional knowledge loss. Conclusion Given the remarkable acculturation processes occurring at present in rural communities of Northwestern Patagonia, it might be of vital importance to document traditional knowledge of ancient practices. Moreover, it could be interesting to share our results with both populations in order to encourage participatory activities within the communities which could enhance traditional knowledge horizontal transmission, particularly among

Rehabilitación de la Patagonia. Un territorio periférico escrito por la narrativa argentina actual

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Alejandro Gasel

2011-06-01

Full Text Available La comunicación consiste en la exposición de las formas de la inscripción de la Patagonia Austral en la contemporaneidad de la narrativa argentina. Puntualmente pensando dos novelas: Falsa Calma de Sonia Cristoff (2004 y La Siberia de Cristina Siscar (2006 trataremos de razonar qué sigue de vigente y qué aparece como una rehabilitación de este territorio en el proceso de producción narrativa. En este sentido, pensamos que podemos plantear no solamente el fenómeno de la representación actual de este territorio sino la productividad reconocida en los textos a partir de un juego intertextual, que sincretiza a una memoria precedente que ha descripto y inscripto el territorio con la necesidad de referencia la crisis del presente o actualidad del territorio en formas de umbralidad. Para dar cuenta de este proceso hemos de remitirnos a pensar la enunciación de los textos, los usos de géneros discursivos, en especial, el relato viaje y la implicancia de la historia y la memoria para referirse políticamente a la Patagonia Austral argentina que sigue siendo tematizado en el variopinto paisaje de la Literatura Argentina.

A promising location in Patagonia for paleoclimate and paleoenvironmental reconstructions revealed by shallow firn core from Monte San Valentin (Northern patagonia Icefield, Chile)

DEFF Research Database (Denmark)

Vimeux, F.; de Angelis, M.; Ginot, P.

2008-01-01

temperature is -11.9°C at 10-m depth allowing to expect well preserved both chemical and isotopic signals, unperturbed by water percolation. The dating of the core, on the basis of a multi-proxy approach combining annual layer counting and radionuclide measurements, shows that past environment and climate can......The study of past climate variability from ice core investigations has been largely developed both in polar areas over the past decades and, more recently, in tropical regions, specifically along the South American Andes between 0° and 20°S. However a large gap still remains at mid......-latitudes in the Southern Hemisphere. In this framework, a 15.3-m long shallow firn core has been extracted in March 2005 from the summit plateau of Monte San Valentín (3747 m, 46°35'S, 73°19'W) in the Northern Patagonia Icefield to test its potential for paleoclimate and paleoenvironmental reconstructions. The firn...

Distribución del ictioplancton en la Patagonia austral de Chile: potenciales efectos del deshielo de Campos de Hielo Sur Ichthyoplankton distribution in South Patagonia, Chile: potential effects of ice melting from the Southern Ice Field

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Mauricio F Landaeta

2011-07-01

Full Text Available Durante octubre-noviembre de 2009 se realizó un crucero oceanográfico entre 50 y 53°S de Chile austral, en las cercanías del glaciar Campos de Hielo Sur. Las estaciones cercanas al glaciar presentaron baja temperatura (1-3°C y salinidad ( 0,1 ciclos s-1. Los principales taxa del ictioplancton fueron huevos y larvas de sardina fueguina Sprattus fuegensis, pez hacha Maurolicus parvipinnis, Macrouridae y merluza austral Merluccius australis. El desove principal de S. fuegensis (~ 8000 huevos 10 m-2 ocurrió en zonas mezcladas de la plataforma continental adyacente, mientras que el desove de M. parvipinnis ocurrió en canales intermedios asociado a valores intermedios de estabilidad (N~0,06 ciclos s-1. Se observó una nula o baja abundancia de huevos y larvas de peces en las cercanías del glaciar, y la abundancia de huevos de M. parvipinnis estuvo relacionada positivamente con la temperatura y salinidad de la columna de agua y negativamente con la estabilidad de la columna de agua. Además, hubo una relación negativa entre la densidad del agua de mar y el diámetro de los huevos de S. fuegensis. La relación entre deshielo e ictioplancton podría tener consecuencias en el transporte advectivo y mortalidad masiva de huevos y larvas de peces y el acople pelágico-bentónico en la Patagonia austral de Chile. Como el cambio climático global ha incrementado los deshielos de glaciares en latitudes altas, y el aumento del ingreso de aguas de baja temperatura y salinidad podría tener consecuencias en el ictioplancton de la Patagonia chilena.In October-November 2009, an oceanographic survey was carried out between 50 and 53°S off southern Chile, near the Southern Ice Field. The stations near the glacier showed low temperatures (1-3°C and salinity ( 0.1 cycles s-1. Main ichthyoplankton taxa were eggs and larvae of southern sprat Sprattus fuegensis, lightfish Maurolicus parvipinnis, Macrouridae, and southern hake Merluccius australis. The main

Sexual dimorphism in the mandible of the armadillo Chaetophractus villosus (Desmarest, 1804) (Dasypodidae) from northern Patagonia, Argentina

OpenAIRE

Squarcia, SM.; Sidorkewicj, NS.; Camina, R.; Casanave, EB.

2009-01-01

The aim of this study was to study the sexual dimorphism in adult Chaetophractus villosus (Desmarest, 1804), from northern Patagonia, Argentina. Eight mandibular traits were measured in 37 males and 34 females. Univariate and multivariate morphometric analysis were applied to the data set. Results showed that C. villosus was sexually dimorphic, with higher absolute values corresponding to females. The total length of the mandible was the most important variable to discriminate sexes, followed...

Revisión de la distribución de Hyalella Smith, 1874 (Crustacea, Amphipoda) en la Patagonia e islas adyacentes Revision of the distribution of Hyalella Smith, 1874 (Crustacea, Amphipoda) in Patagonia and adjacent islands

OpenAIRE

Patricio De los Ríos-Escalante; Andrés Mansilla; Christopher B Anderson

2012-01-01

Se realiza una revisión de las especies de anfípodos del género Hyalella en aguas continentales de la Patagonia, isla Tierra del Fuego, Reserva de la Biosfera de Cabo de Hornos e islas adyacentes (38-54°S). Esta zona austral presenta numerosos tipos de ambientes acuáticos continentales como lagos, humedales y arroyos, y las principales especies en ambientes bentónicos corresponden a anfípodos del género Hyalella. La bibliografía menciona la presencia de H. costera, H. chiloensis, H. falklande...

A new species of Parapsectrocladius Cranston (Diptera: Chironomidae: Orthocladiinae) from Patagonia, Argentina.

Science.gov (United States)

Donato, Mariano; Mauad, Melina; Fuentes, María Cecilia

2015-01-21

Parapsectrocladius setosus sp. n. is described and figured as pupa and male imago, based on material collected in Patagonia, Argentina. The male of the new species groups with P. escondido Cranston & Añón Suárez by having the anal point tapering triangular; inferior volsella simple, rounded, without any dorsal ridge and apically blunt. It can be distinguished from P. escondido by the possession of strong setae on the inner margin of inferior volsella. New material of Parapsectrocladius belonging from several localities allows us to emend the generic diagnosis of the adult male, female and larva of Parapsectrocladius, discuss its phylogenetic position and to expand the geographic distribution of P. acuminatus Cranston, P. escondido and P. reissi. Cranston. 

Biometría del esqueleto postcraneal en muestras del Holoceno tardío de la Cuenca del Lago Salitroso (provincia de Santa Cruz

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Barrientos, Gustavo

2001-01-01

Full Text Available El objetivo de la presente comunicación es presentar la información osteométrica correspondiente al esqueleto postcraneal de una muestra de 18 individuos adultos de diferente sexo y edad, provenientes la cuenca del lago Salitroso (N.O. de la provincia de Santa Cruz. Los mismos fueron recuperados a partir de la excavación de chenques y hoquedades naturales sobre roca, con un rango de edades radiocarbónicas situado entre ca. 2500 y 300 años AP. El presente estudio se integra a una investigación de mayores alcances orientada a analizar la evolución de las poblaciones humanas del centro-sur de la Patagonia continental durante el Holoceno tardío. En este estudio se consideraron 45 variables métricas correspondientes a 10 unidades anatómicas del esqueleto postcraneano (húmero, radio, cúbito, clavícula, fémur, tibia, peroné, escápula, sacro y coxal. A nivel de la localidad, se establecieron comparaciones basadas en análisis uni y multivariados entre el conjunto de entierros más antiguo (ca. 2500-1800 años AP con el más reciente (ca. 1000-300 años AP, con la finalidad de detectar diferencias significativas entre ambas submuestras cronológicas. Finalmente, se analizaron los datos regionales en relación con la variabilidad registrada en otras muestras de Patagonia continental (Chubut y sur de Santa Cruz y Tierra del Fuego.

Origin and evolution of the Laguna Potrok Aike maar (Patagonia, Argentina)

Science.gov (United States)

Gebhardt, A. C.; de Batist, M.; Niessen, F.; Anselmetti, F. S.; Ariztegui, D.; Ohlendorf, C.; Zolitschka, B.

2009-04-01

Laguna Potrok Aike, a maar lake in southern-most Patagonia, is located at about 110 m a.s.l. in the Pliocene to late Quaternary Pali Aike Volcanic Field (Santa Cruz, southern Patagonia, Argentina) at about 52°S and 70°W, some 20 km north of the Strait of Magellan and approximately 90 km west of the city of Rio Gallegos. The lake is almost circular and bowl-shaped with a 100 m deep, flat plain in its central part and an approximate diameter of 3.5 km. Steep slopes separate the central plain from the lake shoulder at about 35 m water depth. At present, strong winds permanently mix the entire water column. The closed lake basin contains a sub saline water body and has only episodic inflows with the most important episodic tributary situated on the western shore. Discharge is restricted to major snowmelt events. Laguna Potrok Aike is presently located at the boundary between the Southern Hemispheric Westerlies and the Antarctic Polar Front. The sedimentary regime is thus influenced by climatic and hydrologic conditions related to the Antarctic Circumpolar Current, the Southern Hemispheric Westerlies and sporadic outbreaks of Antarctic polar air masses. Previous studies demonstrated that closed lakes in southern South America are sensitive to variations in the evaporation/precipitation ratio and have experienced drastic lake level changes in the past causing for example the desiccation of the 75 m deep Lago Cardiel during the Late Glacial. Multiproxy environmental reconstruction of the last 16 ka documents that Laguna Potrok Aike is highly sensitive to climate change. Based on an Ar/Ar age determination, the phreatomagmatic tephra that is assumed to relate to the Potrok Aike maar eruption was formed around 770 ka. Thus Laguna Potrok Aike sediments contain almost 0.8 million years of climate history spanning several past glacial-interglacial cycles making it a unique archive for non-tropical and non-polar regions of the Southern Hemisphere. In particular, variations of

Rehabilitación de la Patagonia. Un territorio periférico escrito por la narrativa argentina actual

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Alejandro Gasel

2011-07-01

Full Text Available http://dx.doi.org/10.5007/1984-784X.2011v11n16p50 La comunicación consiste en la exposición de las formas de la inscripción de la Patagonia Austral en la contemporaneidad de la narrativa argentina. Puntualmente pensando dos novelas: Falsa Calma de Sonia Cristoff (2004 y La Siberia de Cristina Siscar (2006  trataremos de razonar qué  sigue de vigente y qué aparece como una rehabilitación  de este territorio en el proceso de producción narrativa. En este sentido, pensamos que podemos plantear  no solamente el fenómeno de la representación actual de este territorio sino la productividad reconocida en los textos a partir de un juego intertextual, que sincretiza a una memoria precedente que ha descripto y inscripto el territorio con la necesidad de referencia la crisis del presente o actualidad del territorio en formas de umbralidad. Para dar cuenta de este proceso  hemos de remitirnos a pensar la enunciación  de los textos, los usos de géneros discursivos, en especial, el relato viaje y la implicancia de la historia y la memoria para referirse políticamente a la Patagonia Austral argentina que sigue siendo tematizado en el variopinto paisaje de la Literatura Argentina.

Cuatro nuevas especies del género Liolaemus (Iguania: Liolaemidae, pertenecientes al grupo boulengeri, de la Patagonia, Argentina

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Abdala, Cristian Simón

2003-12-01

Full Text Available Se describen cuatro nuevas especies del género Liolaemus, pertenecientes al grupo boulengeri, caracterizado por la presencia de un parche femoral de escamas agrandadas en la parte posterior del fémur. Una especie fue colectada en el sur de la provincia de Neuquén y las otras tres en el suroeste, centro y este de la provincia de Río Negro, en la Patagonia Argentina. Dentro del grupo las nuevas especies están relacionadas fenéticamente a Liolaemus boulengeri. Se estudiaron 98 caracteres morfológicos externos, referidos principalmente a caracteres de lepidosis, patrón de coloración y proporciones corporales, corrientemente estudiados en Liolaemus. Las diferencias más significativas entre estas especies y Liolaemus boulengeri se dan principalmente en el patrón de coloración y en algunos caracteres de escamación. Estas especies ocupan parte de las tres regiones patagónicas que se diferencian con base en la orografía y vegetación asociada. Las nuevas especies del centro y suroeste de la provincia de Río Negro, soportan grandes diferencias de temperatura diarias y estacionales. Las cuatro especies que se describen aquí se alimentan principalmente de insectos. Four new species of Liolaemus are described from the Patagonia region of southern Argentina. One species was collected in southern Neuquén Province and the other three are from Río Negro Province. Each of the new species has a patch of enlarged scales on the posterior surface of the thighs, indicating their relationship to members of the boulengeri group. Within this group, the four new species are morphologically most similar, and may be most closely related to, Liolaemus boulengeri. A total of 98 external morphological characters, principally squamation, color pattern, and body proportions, were recorded for these new members of the boulengeri group and compared with those for Liolaemus boulengeri. Significant differences between the new species and Liolaemus boulengeri were

A widespread devonian methamorphic episode in northern Patagonia, Argentina

International Nuclear Information System (INIS)

Ostera, H.A.; Linares, E; Haller, M.J; Cagnoni, M.C.; Lopez de Luchi, M

2001-01-01

One of the greatest difficulties in Rb-Sr dating on metamorphic rocks is the lack of evidences of complete re-homogenization and the assumption of a common initial ratio for all the samples analyzed. The redistribution of parent-daughter elements and the concomitant partial or complete equilibration of the isotopic system could occur on mineral or regional size domains. This fact led to many authors to discard or disapprove the use of this method in metamorphic terranes. However, recent papers suggested that this opinion has been premature and that additional information could be obtained by the Rb-Sr method despite the difficulties that it implies (Patel et al., 1999). Many reports on well fitted Rb-Sr isochrons giving the age of metamorphism in regionally metamorphosed rocks, suggest that the Sr isotopic equilibrium can take place at different scales. This paper presents data and the Rb-Sr system behaviour from a metamorphic unit (Cushamen Formation) in the Northern Patagonia, as a contribution to elucidate the evolution of the North Patagonian Massif (au)

LAS NORMAS JURÍDICAS Y LAS POLÍTICAS PÚBLICAS SOBRE BOSQUES CULTIVADOS EN LAS REGIONES DEL CENTRO Y DE PATAGONIA EN ARGENTINA

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C. M. MINAVERRY

2017-08-01

Full Text Available El eje central de este trabajo es analizar el nivel de desarrollo de las normas jurídicas, de las políticas públicas, y de la idoneidad de las autoridades de aplicación sobre bosques cultivados, en las regiones del Centro y de la Patagonia en Argentina. Se trata de una investigación de carácter exploratorio, donde se aplicó el método de la hermenéutica jurídica y los indicadores ambientales PER. Se puede concluir que los niveles de desarrollo normativo de las provincias no son uniformes, y que la mayoría de las normas jurídicas y de las políticas públicas tienden a establecer incentivos económicos para aprovechar el efecto del mercado, sin orientarse hacia una protección integral de los ecosistemas boscosos, y que las autoridades de aplicación en su mayoría no son técnicamente adecuadas para eso.

Diversos usos instrumentales del aparato masticatorio en restos humanos de la Patagonia Argentina

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Kozameh, Livia Febes

2005-01-01

Full Text Available Desgastes dentarios atípicos y disarmónicos, asociados a patologías sugirieron la posibilidad que los mismos se hubieran producido por una actividad masticatoria excesiva y no alimentaria. La variedad de rastros registrados sugiere el uso de la boca con fines instrumentales, como recurso posiblemente constante. Los casos seleccionados son seis y sus rasgos predominantes se describen sucintamente. 1 Muestra dentaria de canoeros fueguinos. Fracturas cuspídeas pulimentadas únicamente en denticiones femeninas.2Resto de cazador canoero del Beagle. Notables desgastes dentarios con distintas angulaciones a modo de zigzag. Raíces en función oclusal con procesos alveolares concomitantes. 3Resto de cazador pedestre de Tierra del Fuego. Disminución del tamaño coronal de los dientes anteriores y primeros premolares, con pérdida completa de su morfología. Los bordes incisales exhiben tres planos de desgaste con diferentes direcciones. 4 y 5Cazadores de Santa Cruz. En uno de ellos los desgastes coronales son convexos en todos sus dientes. Patologías alveolares. En el otro ejemplar el desgaste tornó cilíndricas las coronas de las piezas anteriores. 6Resto femenino de Chubut. Pérdida prematura de los cuatro dientes anteriores con compromiso óseo y canino transpuesto.

Los dueños del rebaño. Origen étnico y capacidad ovina en Chubut

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Fernando Coronato

2015-04-01

Full Text Available Continuando la línea de investigación inaugurada por Elsa Barbería en “Los dueños de la tierra” en Santa Cruz, avanzamos sobre la distribución de las diferentes comunidades étnicas y su parte en el poblamiento patagónico a partir del análisis cartográfico diacrónico. Para el último período del proceso utilizamos la base de datos del catastro del Chubut (2006 para evaluar « la capacidad ganadera» (entendida como la acumulación de hectáreas y ovinos de cada comunidad étnica. Estas fueron asociadas a los grupos patronímicos identificados previamente, a saber: alemán, bóer, británico (inglés y escocés, español, francés, galés, italiano, mapuche, polaco, tehuelche y vasco. Las Sociedades Anónimas se consideraron como un grupo aparte. Del tratamiento estadístico de los datos se obtuvo la superficie media de las (más de 2000 propiedades, la talla media del rebaño y la cosecha de lana de cada grupo, detectándose diferencias significativas entre algunos de ellos. Las Sociedades Anónimas se despegan solitarias hacia los latifundios, mientras que en el extremo opuesto se ubican los grupos aborígenes, arrinconados en los minifundios y la subsistencia. Estos datos relativamente actuales muestran la continuidad de los procesos identificados en el análisis catastral de etapas previas del poblamiento que se remontan a más de un siglo.

INVITACIÓN AL GEOTURISMO. REFLEXIONES SOBRE GEODIVERSIDAD Y POTENCIAL GEOTURÍSTICO EN LA PATAGONIA ARGENTINA

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María de la Paloma Martínez Fernandez

2013-12-01

Full Text Available Geotourism as a type of nature tourism comes to fill an empty field on the use of geological resources of the landscape in Argentina. With an approach sustained by the ideas and progresses achieved along the last decades about sustainable tourism, geosites and geoparks are getting a boost worldwide. However, in Argentina this concept has not being incorporated yet within public or private touristic policies, despite owning a valuable geodiversity both scientific or aesthetically. Based on a review of concepts and foreign experiences on the subject, this article analyses the possibilities and parameters for geotourism developing in Argentinean Patagonia.

Respuesta del microfitoplancton a la adición de nitrato y ácido silícico en fiordos de la Patagonia chilena

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Pamela Labbé-Ibáñez

2015-03-01

Full Text Available La Patagonia chilena está experimentando un aumento del uso del suelo y océano costero y el acelerado derretimiento de algunos glaciares, por lo que uno de los escenarios a futuro es que los fiordos adyacentes reciban cantidades variables de agua dulce y nutrientes inorgánicos. Se estudió la respuesta de ensambles de fitoplancton de los fiordos Reloncaví en invierno y Comau en primavera, a la adición de nitrato y ácido silícico en experimentos de microcosmos. Los ensambles fitoplanctónicos estudiados respondieron a la adición de nutrientes con incrementos en la abundancia celular biomasa autotrófica (clorofila-a y cambios en la composición específica, destacando el cambio de dominancia de especies de diatomeas pennadas a céntricas formadoras de cadenas. Estos resultados dan indicios acerca de los factores que afectan a las comunidades microalgales en un escenario de cambio climático e intervención antrópica de los fiordos de la Patagonia Norte.

Noble gas composition of subcontinental lithospheric mantle: An extensively degassed reservoir beneath Southern Patagonia

Science.gov (United States)

Jalowitzki, Tiago; Sumino, Hirochika; Conceição, Rommulo V.; Orihashi, Yuji; Nagao, Keisuke; Bertotto, Gustavo W.; Balbinot, Eduardo; Schilling, Manuel E.; Gervasoni, Fernanda

2016-09-01

Patagonia, in the Southern Andes, is one of the few locations where interactions between the oceanic and continental lithosphere can be studied due to subduction of an active spreading ridge beneath the continent. In order to characterize the noble gas composition of Patagonian subcontinental lithospheric mantle (SCLM), we present the first noble gas data alongside new lithophile (Sr-Nd-Pb) isotopic data for mantle xenoliths from Pali-Aike Volcanic Field and Gobernador Gregores, Southern Patagonia. Based on noble gas isotopic compositions, Pali-Aike mantle xenoliths represent intrinsic SCLM with higher (U + Th + K)/(3He, 22Ne, 36Ar) ratios than the mid-ocean ridge basalt (MORB) source. This reservoir shows slightly radiogenic helium (3He/4He = 6.84-6.90 RA), coupled with a strongly nucleogenic neon signature (mantle source 21Ne/22Ne = 0.085-0.094). The 40Ar/36Ar ratios vary from a near-atmospheric ratio of 510 up to 17700, with mantle source 40Ar/36Ar between 31100-6800+9400 and 54000-9600+14200. In addition, the 3He/22Ne ratios for the local SCLM endmember, at 12.03 ± 0.15 to 13.66 ± 0.37, are higher than depleted MORBs, at 3He/22Ne = 8.31-9.75. Although asthenospheric mantle upwelling through the Patagonian slab window would result in a MORB-like metasomatism after collision of the South Chile Ridge with the Chile trench ca. 14 Ma, this mantle reservoir could have remained unhomogenized after rapid passage and northward migration of the Chile Triple Junction. The mantle endmember xenon isotopic ratios of Pali-Aike mantle xenoliths, which is first defined for any SCLM-derived samples, show values indistinguishable from the MORB source (129Xe/132Xe =1.0833-0.0053+0.0216 and 136Xe/132Xe =0.3761-0.0034+0.0246). The noble gas component observed in Gobernador Gregores mantle xenoliths is characterized by isotopic compositions in the MORB range in terms of helium (3He/4He = 7.17-7.37 RA), but with slightly nucleogenic neon (mantle source 21Ne/22Ne = 0.065-0.079). We

Getting water right: A case study in water yield modelling based on precipitation data.

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Pessacg, Natalia; Flaherty, Silvia; Brandizi, Laura; Solman, Silvina; Pascual, Miguel

2015-12-15

Water yield is a key ecosystem service in river basins and especially in dry regions around the World. In this study we carry out a modelling analysis of water yields in the Chubut River basin, located in one of the driest districts of Patagonia, Argentina. We focus on the uncertainty around precipitation data, a driver of paramount importance for water yield. The objectives of this study are to: i) explore the spatial and numeric differences among six widely used global precipitation datasets for this region, ii) test them against data from independent ground stations, and iii) explore the effects of precipitation data uncertainty on simulations of water yield. The simulations were performed using the ecosystem services model InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) with each of the six different precipitation datasets as input. Our results show marked differences among datasets for the Chubut watershed region, both in the magnitude of precipitations and their spatial arrangement. Five of the precipitation databases overestimate the precipitation over the basin by 50% or more, particularly over the more humid western range. Meanwhile, the remaining dataset (Tropical Rainfall Measuring Mission - TRMM), based on satellite measurements, adjusts well to the observed rainfall in different stations throughout the watershed and provides a better representation of the precipitation gradient characteristic of the rain shadow of the Andes. The observed differences among datasets in the representation of the rainfall gradient translate into large differences in water yield simulations. Errors in precipitation of +30% (-30%) amplify to water yield errors ranging from 50 to 150% (-45 to -60%) in some sub-basins. These results highlight the importance of assessing uncertainties in main input data when quantifying and mapping ecosystem services with biophysical models and cautions about the undisputed use of global environmental datasets. Copyright �

210 Pb fluxes in sediment layers sampled from Northern Patagonia lakes

International Nuclear Information System (INIS)

Ribeiro Guevara, S.; Sanchez, R.; Arribere, M.; Rizzo, A.

2003-01-01

Unsupported 210 Pb fluxes were determined from sediment core inventories in lakes located in Northern Patagonia, Argentina. Total 210 Pb, 226 Ra, associated with supported 210 Pb, and 137 Cs specific activity profiles were measured by gamma-ray spectrometry. Unsupported 210 Pb fluxes showed very low values when compared to other regions, with a 12 fold variation, ranging from 4 to 48 Bq m -2 x y -1 . The linear correlation observed between the 210 Pb fluxes and 137 Cs cumulative fluxes in sediment cores sampled from water bodies within a zone with similar precipitation demonstrated that both radioisotopes behave in the same manner in these systems concerning the processes occurred from fallout to sediment deposition, and that there are no appreciable local or regional sources of unsupported 210 Pb. Positive correlation of 210 Pb fluxes with organic matter contents of the uppermost sediment core layers was also observed. (author)

A Gigantic, Exceptionally Complete Titanosaurian Sauropod Dinosaur from Southern Patagonia, Argentina

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Lacovara, Kenneth J.; Lamanna, Matthew C.; Ibiricu, Lucio M.; Poole, Jason C.; Schroeter, Elena R.; Ullmann, Paul V.; Voegele, Kristyn K.; Boles, Zachary M.; Carter, Aja M.; Fowler, Emma K.; Egerton, Victoria M.; Moyer, Alison E.; Coughenour, Christopher L.; Schein, Jason P.; Harris, Jerald D.; Martínez, Rubén D.; Novas, Fernando E.

2014-01-01

Titanosaurian sauropod dinosaurs were the most diverse and abundant large-bodied herbivores in the southern continents during the final 30 million years of the Mesozoic Era. Several titanosaur species are regarded as the most massive land-living animals yet discovered; nevertheless, nearly all of these giant titanosaurs are known only from very incomplete fossils, hindering a detailed understanding of their anatomy. Here we describe a new and gigantic titanosaur, Dreadnoughtus schrani, from Upper Cretaceous sediments in southern Patagonia, Argentina. Represented by approximately 70% of the postcranial skeleton, plus craniodental remains, Dreadnoughtus is the most complete giant titanosaur yet discovered, and provides new insight into the morphology and evolutionary history of these colossal animals. Furthermore, despite its estimated mass of about 59.3 metric tons, the bone histology of the Dreadnoughtus type specimen reveals that this individual was still growing at the time of death. PMID:25186586

Nueva especie de Planorbidae (Gastropoda: Basommatophora en la Patagonia chilena: Biomphalaria cristiani sp. nov. First record of Planorbidae (Mollusca: Basommatophora in Chilean Patagonia: Biomphalaria cristiani sp. nov.

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Carmen Fuentealba

2012-11-01

Full Text Available En Chile la familia Planorbidae está representada por el género Biomphalaria Preston, 1910, compuesta por siete especies distribuidas desde Isluga hasta el río Puelo. De estas especies, solo B.peregrina, ampliamente distribuida en el neotrópico, y Biomphalaria aymara de Isluga, han sido reconocidas sobre la base de la morfología del sistema reproductor y la rádula, caracteres que fueron utilizados en el presente estudio para diferenciar a Biomphalaria cristiani como nueva especie del grupo y primer registro de la familia en la Patagonia chilena, ampliando su actual rango de distribución. Los caracteres que permiten la diagnosis de B. cristiani son el saco vaginal vestigial truncado, ausencia del desarrollo de los músculos suspensores del pene, vaina del pene corta en relación al prepucio, oviducto largo en relación al espermioducto y vaso deferente más delgado y largo que la vaina del pene, de tamano similar al prepucio. La localidad tipo de Biomphalaria cristiani sp. nov. es Laguna Cisnes (47°7'10.02"S, 72°27'40.65"W, región de Aysén.The family Planorbidae in Chile is represented by the genus Biomphalaria Preston, 1910, consisting of seven species distributed from Isluga to Puelo River. Of these species, only Biomphalaria peregrina widely distributed in the neotropical and Biomphalaria aymara from Isluga are recognized based on the morphology of the reproductive system and radula, characters that were used in the following study to differentiate Biomphalaria cristiani as a new species of this group and first record of the family in Chilean Patagonia, extending its current distribution range. The characters for the diagnosis of B. cristiani are: truncated vestigial vaginal pouch, lack of development of the penis retractor muscles, penis sheath shorter than the prepuce, oviduct longer than the spermiduct and vas deferens thinner and longer than the penis sheath, similar size to the prepuce. The type locality of B. cristiani nov. sp

Aportes de los "intermediarios culturales" en la conformación de los paisajes fronterizos del norte de la patagonia a fines del siglo XVIII

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Laura Aylén Enrique

2012-12-01

Full Text Available A fines del siglo XVIII la Corona española envió expedicionarios a reconocer el norte de la Patagonia, un territorio dominado por grupos indígenas pero de importancia estratégica para los hispanocriollos. Los funcionarios del Virreinato del Río de la Plata que llevaron a cabo dichas exploraciones registraron sus impresiones en diarios de viaje que analizamos con el objetivo de examinar los modos en que el paisaje norpatagónico fue construido simbólicamente. Consideramos que dicho paisaje se constituyó en base a las luchas desplegadas tanto por hispanocriollos como por indígenas buscando dar sentido al territorio. Sostenemos que, en este contexto, los personajes que se desempeñaban como intérpretes ejercían un rol fundamental en la configuración del territorio, dada la ambigüedad de su posición de intermediarios en las relaciones interétnicas.By late eighteen century the Spanish Crown sent expedition to recognize north Patagonia, a territory dominated by indigenous groups but also of strategic importance to the Hispanic-Creole population. River Plate Viceroyalty officials in charge of the above-mentioned explorations registered their impressions in travel diaries that are thoroughly analyzed in order to discover the ways this landscape of north Patagonia was symbolically constructed. We think this mestizo landscape was the result of struggles maintained between Hispanic-Creoles and natives searching to convey meaning to the territory. Moreover, we state that in this context, the actors who served as interpreters developed a key role in the territorial configuration, given the ambiguity of their position as intermediaries of interethnic relations.

Modelling Soil Carbon Content in South Patagonia and Evaluating Changes According to Climate, Vegetation, Desertification and Grazing

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Pablo Luis Peri

2018-02-01

Full Text Available In Southern Patagonia, a long-term monitoring network has been established to assess bio-indicators as an early warning of environmental changes due to climate change and human activities. Soil organic carbon (SOC content in rangelands provides a range of important ecosystem services and supports the capacity of the land to sustain plant and animal productivity. The objectives in this study were to model SOC (30 cm stocks at a regional scale using climatic, topographic and vegetation variables, and to establish a baseline that can be used as an indicator of rangeland condition. For modelling, we used a stepwise multiple regression to identify variables that explain SOC variation at the landscape scale. With the SOC model, we obtained a SOC map for the entire Santa Cruz province, where the variables derived from the multiple linear regression models were integrated into a geographic information system (GIS. SOC stock to 30 cm ranged from 1.38 to 32.63 kg C m−2. The fitted model explained 76.4% of SOC variation using as independent variables isothermality, precipitation seasonality and vegetation cover expressed as a normalized difference vegetation index. The SOC map discriminated in three categories (low, medium, high determined patterns among environmental and land use variables. For example, SOC decreased with desertification due to erosion processes. The understanding and mapping of SOC in Patagonia contributes as a bridge across main issues such as climate change, desertification and biodiversity conservation.

Insectos acuáticos de la Meseta del Somuncura, Patagonia, Argentina. Inventario preliminar

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Javier MUZÓN

2005-01-01

Full Text Available Se brinda un inventario preliminar de los insectos acuáticos de la Meseta del Somuncura y su área de influencia (Patagonia, Argentina realizado sobre la base de colecciones y registros previos de especies pertenecientes a los órdenes Ephemeroptera, Odonata, Hemiptera (Heteroptera, Trichoptera, Diptera (familias Ceratopogonidae, Culicidae y Psychodidae y Coleoptera. Se han relevado diversos tipos de ambientes en 14 localidades. El número de especies registrado asciende a 78, agrupadas en 51 géneros y 26 familias, de las cuales 33 se citan por primera vez del área. De los taxa registrados 83% de los géneros corresponden a grupos de amplia distribución (neotropicales, americanos o cosmopolitas, mientras que 41% de las especies presentan una distribución patagónica o andina.

Toxocariasis in Carnivora from Argentinean Patagonia: Species molecular identification, hosts, and geographical distribution

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R.M. Vega

2018-04-01

Full Text Available Twenty four specimens of seven species belonging to the families Felidae, Mustelidae, and Canidae were obtained in Lanín and Nahuel Huapi National Parks from March 1996 to April 2016. Specimens were processed by necropsy in order to contribute to the knowledge of toxocariasis in wild carnivores of Argentinean Patagonia. The only Puma concolor and the seven Leopardus geoffroyi were positive for Toxocara cati. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP of the ITS-1 region from larval and adult DNA was carried out to confirm parasite species identification. This is the first molecular determination of T. cati from wild felids in Argentina and the study also fill gaps about the spatial distribution and hosts for Toxocara cati. Keywords: Toxocara cati, Puma concolor, Leopardus geoffroyi, Molecular identification, Argentina

Estado actual de las investigaciones tafonómicas naturalistas en Punta Entrada y Monte León (patagonia meridional)

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Muñoz, Sebastián Ramón; Cruz, Isabel

2017-01-01

Se presentan los resultados de las investigaciones tafonómicas naturalistas realizadas desde 2005 en la desembocadura del río Santa Cruz y el parque Nacional Monte león (Patagonia Meridional) dirigidas a conocer los modos en que tiene lugar el reciclado de restos de vertebrados en un mismo contexto ambiental, la estepa costera patagónica. Se resume el conocimiento generado sobre: el tiempo involucrado en la desarticulación de carcasas de vertebrados; los procesos y actores intervinientes y ...

Análisis del gradiente edáfico en la región Andinopatagónica Analysis of soil gradient in Andean Patagonia Region

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Juan José Gaitán

2007-07-01

Full Text Available Se analizaron las relaciones entre la ubicación geográfica, precipitación media anual y nueve variables edáficas de 95 perfiles de suelos de origen volcánico distribuidos a lo largo de la región Andina de las provincias de Neuquén, Río Negro y Chubut. Con las variables edáficas correspondientes a dos profundidades (0-20 cm y 30-60 cm se realizó un análisis de cluster que permitió agrupar a los perfiles en cinco grupos principales. Se realizó un análisis de componentes principales y se observó que los grupos se diferenciaron a lo largo del eje 1. Este eje se relaciona con la longitud. Desde los suelos de régimen xérico de estepa ubicados en el este de la región hacia los suelos de régimen údico de bosque ubicados en el oeste, se incrementa el pH (NaF, la concentración de carbono orgánico y la capacidad de retención hídrica y disminuye, el pH (H2O, el pH (KCl y la densidad aparente.The relationships among location, mean annual precipitation and nine edaphic variables were studied for 95 profiles of volcanic soils throughout the Andean Region of the provinces of Neuquen, Rio Negro and Chubut. A cluster analysis conducted with the edaphic variables at two depths (0-20 cm and 30-60 cm indicated five main groups. Principal component analysis (PCA allowed to differentiate the groups for the axis 1. This axis was positively related to longitude, indicating an increase of pH (NaF, organic C and water retention capacity, and a decrease of pH (H2O, pH (KCl and bulk density from the xeric steppe soils at east to the udic forest soils at west.

Is forage productivity of meadows influenced by the afforestation of upstream hillsides? A study in NW Patagonia

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Weigandt, M.; Gyenge, J.; Fernandez, M. E.; Varela, S.; Schlichter, T.

2011-07-01

Meadows are important reserves of water, with a key role in the maintenance of the biodiversity and productivity of ecosystems. In Patagonia, Argentina, afforestation with fast-growing exotic conifers has slowly but continuously increased over recent decades; though unfortunately, knowledge of the effects of afforestation on water resources remains scarce, with no information at all related to its impact on water dynamics and productivity of meadows located down slope to it. The effects of Pinus ponderosa afforestation on water dynamics (soil moisture contents and groundwater level) and productivity (aboveground forage productivity) of Northwest Patagonia meadows under xeric and humid conditions were analyzed. In the humid meadow, gravimetric soil water content, groundwater level and forage productivity were similar down slope of forested and non-forested slopes, with a trend towards higher forage productivity on the forested slope. In the xeric meadow, gravimetric soil water content was always higher down slope of the non-forested slope, with no difference in groundwater level between treatments. Forage productivity was statistically similar between situations (down slope of forested and non-forested slopes), with a trend towards higher productivity in the zone with higher soil water content. The main difference in the latter was related to differences in soil texture between zones. These results suggest that coniferous plantations located upstream of this type of meadow do not produce a direct effect on its aboveground forage productivity. These systems have high complexity linked to precipitation, geomorphology and previous history of land use, which determine primarily soil water dynamics and consequently, forage productivity. (Author) 42 refs.

La evolución del espacio social y urbano en la capital de la Patagonia chilena. Punta Arenas

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Luis Inostroza Pino

2008-05-01

Razones del contexto mundial apoyadas por adecuadas decisiones a nivel local, son las que permitieron el desarrollo de la Patagonia y de la ciudad de Punta Arenas fundamentalmente hasta fines del siglo XIX. La iniciación del tráfico regular entre Europa y el Pacífico, con recalada obligada en la colonia, y las medidas de Puerto libre y de incentivo a la inmigración de colonos nacionales y extranjeros, influirán decisivamente en ese desarrollo. El modesto pueblo se transforma en un importante centro urbano.

APOROCOTYLE MARIACHRISTINAE N. SP., AND A. YMAKARA VILLALBA & FERNANDEZ, 1986 (DIGENEA: APOROCOTYLIDAE) OF THE PINK CUSK-EEL, GENYPTERUS BLACODES (OPHIDIIFORMES: OPHIDIIDAE) FROM PATAGONIA, ARGENTINA

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Hernandez-Orts, J.S.; Alama-Bermejo, Gema; Carillo, J.M.; García, N.A.; Crespo, E.A.; Raga, J. A.; Montero, E. E.

2012-01-01

Roč. 19, č. 4 (2012), s. 319-330 ISSN 1252-607X R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Aporocotylidae * Aporocotyle * A. mariachristinae n. sp. * A. ymakara * Genypterus blacodes * Ophidiidae * Patagonia * Argentina * rDNA sequences Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.116, year: 2012

Forest Typification to Characterize the Structure and Composition of Old-growth Evergreen Forests on Chiloe Island, North Patagonia (Chile

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Jan R. Bannister

2013-11-01

Full Text Available The Evergreen forest type develops along the Valdivian and North-Patagonian phytogeographical regions of the south-central part of Chile (38° S–46° S. These evergreen forests have been scarcely studied south of 43° S, where there is still a large area made up of old-growth forests. Silvicultural proposals for the Evergreen forest type have been based on northern Evergreen forests, so that the characterization of the structure and composition of southern Evergreen forests, e.g., their typification, would aid in the development of appropriate silvicultural proposals for these forests. Based on the tree composition of 46 sampled plots in old-growth forests in an area of >1000 ha in southern Chiloé Island (43° S, we used multivariate analyses to define forest groups and to compare these forests with other evergreen forests throughout the Archipelago of North-Patagonia. We determined that evergreen forests of southern Chiloé correspond to the North-Patagonian temperate rainforests that are characterized by few tree species of different shade tolerance growing on fragile soils. We discuss the convenience of developing continuous cover forest management for these forests, rather than selective cuts or even-aged management that is proposed in the current legislation. This study is a contribution to forest classification for both ecologically- and forestry-oriented purposes.

Composición corporal de escolares pertenecientes a diferentes contextos socioeconómicos de Puerto Madryn, Chubut, Argentina

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Dahinten, Silvia Lucrecia

2007-01-01

Full Text Available El desigual desarrollo del tejido muscular y de la distribución de tejido adiposo que tiene lugar durante el crecimiento humano presenta dimorfismo sexual (DS, en condiciones de vida saludables. Esta variación ha sido traducida en algoritmos utilizando la circunferencia y pliegues subcutáneos del brazo y se han elaborado ecuaciones para calcular áreas. El objetivo fue evaluar el DS observado en el crecimiento corporal de escolares de 6 a 14 años de hogares con diferente NBI -(NBI alto y (NBI bajo-. Se estudió transversalmente una muestra de 500 mujeres y 570 varones de la ciudad de Puerto Madryn, Chubut. Se relevaron: perímetro braquial y pliegues subcutáneos tricipital y subescapular y se calcularon las áreas adiposa (AAB y muscular (AMB. Se utilizaron pruebas de Wilcoxon, p= 0.05. El AAB de las mujeres fue a casi todas las edades superior a la de los varones (NBI bajo p=0.09; NBI alto p=0.02. A edades tempranas, el AMB mostró que los varones presentaron cifras similares a las mujeres. A partir de los 12 años, sin embargo, los varones comenzaron a incrementar la masa muscular. En las niñas este aumento se hizo mucho más lento (NBI alto p=0.01; NBI bajo p=0.03. La ausencia de DS en el NBI bajo, para los caracteres considerados, se relaciona con el aumento de tejido adiposo en los varones de este sector que muestra la adopción dentro de la comunidad, de dietas de alto contenido en grasas y carbohidratos acompañadas de altas tasas de obesidad.

Polen y vegetación en la Patagonia extraandina argentina a 45º S

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Burry, Lidia S.

2005-12-01

Full Text Available Modern pollen dispersal and deposition in relation to vegetation and environmental variables at 45° S was studied in Argentinian Patagonia east of the Andes to build a modern pollen model. This model will serve to identify modern pollen assemblages that are analog of past pollen assemblages. A west-to-east gradient of decreasing precipitation and increasing temperature determines four vegetation units: (1 grass steppe, (2 grass-bush steppe, (3 bush steppe and (4 bush-brush steppe. Pollen samples were analyzed by classification and ordination methods, and correlated to environmental variables. The steppes (a dominated by the functional type grass, (1 grass steppe, and (2 grass-bush steppe located in the more humid and cooler west end of the region were separated from the (b bush-dominated steppes (3 bush steppe and (4 bush-brush steppe occurring in the central and eastern parts of the region, where conditions are drier and warmer. Azonal communities were identified as halophytic bush steppes within different vegetation units along the west-east gradient. Environmental variables related to vegetation distribution are temperature and interannual precipitation variability associated with the precipitation gradient from the cordillera to the coast, and soil salinity in the case of azonal communities.Se investigó la relación de la dispersión-deposición del polen actual con la vegetación y con variables ambientales en la Patagonia extraandina argentina a 45° S con el fin de construir un modelo polínico actual. Este modelo servirá para identificar los conjuntos polínicos actuales que sean análogos de conjuntos polínicos fósiles. En la región hay un gradiente decreciente de precipitación y creciente de temperatura de oeste a este, que determina la existencia de diferentes unidades de vegetación: (1 estepa graminosa; (2 estepa graminosa-arbustiva; (3 estepa arbustiva y (4 estepa arbustiva-matorral. Los datos de polen de muestras de suelo

Crecimiento anual de cuatro especies arbóreas con yemas desnudas nativas de los bosques templados húmedos de Patagonia

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Sosa, Claudia M; Puntieri, Javier G

2016-01-01

Las especies vegetales que habitan en regiones con bajo nivel de estacionalidad en el clima suelen presentar rasgos morfo-arquitecturales que ocurren con menor frecuencia en especies de regiones con clima estacional. El objetivo de este estudio fue evaluar el crecimiento primario en vivero de cuatro especies leñosas típicas de los bosques templados húmedos de Patagonia, conocidos como selva valdiviana, donde el grado de estacionalidad es menos marcado que en otros bosques patagónicos. Las esp...

Cystobasidiomycetes yeasts from Patagonia (Argentina): description of Rhodotorula meli sp. nov. from glacial meltwater.

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Libkind, Diego; Sampaio, José Paulo; van Broock, Maria

2010-09-01

A basidiomycetous yeast, strain CRUB 1032(T), which formed salmon-pink colonies, was isolated from glacial meltwater in Patagonia, Argentina. Morphological, physiological and biochemical characterization indicated that this strain belonged to the genus Rhodotorula. Molecular taxonomic analysis based on the 26S rDNA D1/D2 domain and internal transcribed spacer region sequences showed that strain CRUB 1032(T) represents an undescribed yeast species, for which the name Rhodotorula meli sp. nov. is proposed (type strain is CRUB 1032(T)=CBS 10797(T)=JCM 15319(T)). Phylogenetic analysis showed that Rhodotorula lamellibrachii was the closest known species, which, together with R. meli, formed a separate cluster related to the Sakaguchia clade within the Cystobasidiomycetes. Additional Patagonian yeast isolates of the class Cystobasidiomycetes are also investigated in the present work.

A large Cretaceous theropod from Patagonia, Argentina, and the evolution of carcharodontosaurids

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Novas, Fernando E.; Valais, Silvina; Vickers-Rich, Pat; Rich, Tom

2005-05-01

The Cretaceous Carcharodontosauridae is the latest clade of carnosaurs, including the largest predatory dinosaurs yet recorded. Albeit spectacular for their size, the skeletal anatomy of these theropods remains poorly-known, and their diversity was until recently restricted to two Cenomanian species: the highly derived Giganotosaurus carolinii, from southern South America, and the incompletely known Carcharodontosaurus saharicus, from northern Africa. Here we describe an older and basal member of the group, Tyrannotitan chubutensis gen. et sp. nov., from Aptian strata of Patagonia, Argentina. The new taxon gives new insights into the systematics and evolution of carcharodontosaurids and offers a better understanding of the evolution of Southern theropod faunas. We suggest that carcharodontosaurids radiated in Gondwana sharing with spinosaurids the role of top-predators until their extinction in Cenomanian Turonian times. During this interval, the diplodocoid sauropods and giant titanosaurians went extinct (probably as part of a global-scale crisis), and the smaller abelisaurid theropods took dominance, reigning until the end of the Cretaceous. Electronic Supplementary Material is available.

Hydroclimatic conditions trigger record harmful algal bloom in western Patagonia (summer 2016).

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León-Muñoz, Jorge; Urbina, Mauricio A; Garreaud, René; Iriarte, José Luis

2018-01-22

A harmful algal bloom (HAB) of the raphidophyta alga Pseudochattonella cf. verruculosa during the 2016 austral summer (February-March) killed nearly 12% of the Chilean salmon production, causing the worst mass mortality of fish and shellfish ever recorded in the coastal waters of western Patagonia. The HAB coincided with a strong El Niño event and the positive phase of the Southern Annular Mode that altered the atmospheric circulation in southern South America and the adjacent Pacific Ocean. This led to very dry conditions and higher than normal solar radiation reaching the surface. Using time series of atmospheric, hydrologic and oceanographic data we show here that an increase in surface water temperature and reduced freshwater input resulted in a weakening of the vertical stratification in the fjords and sounds of this region. This allowed the advection of more saline and nutrient-rich waters, ultimately resulting in an active harmful algal bloom in coastal southern Chile.

Ethical and Civic Education. Difficulties during the Curricular Reform in Argentine Patagonia

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Isabelino Siede

2015-04-01

Full Text Available DOI: http://dx.doi.org/10.17227/01234870.41folios51.68 What type of ethical and civic education is effectively provided at school? This article analyzes the curricular prescriptions of Ethical and Citizenship Education in primary schools of the Argentine Patagonia, as well as its relations and contradictions with the school practices of moral education It inquires the process of definition of the area in the context of the Educational Reform in the 90s. Also, it pursuits to remake the way it was incorporated in the provincial curriculum design. Throughout focus groups and interviews to teachers from different public and private schools of three towns from de north of Santa Cruz, we analyze the descriptions and expectative of the teachers about their teaching practice in the moral area, as well as the possible causes of the differences and the contradictions between the policies of the curricular statement and educational proposals offered at school.

A single haplotype hyposensitive to light and requiring strong vernalization dominates Arabidopsis thaliana populations in Patagonia, Argentina.

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Kasulin, Luciana; Rowan, Beth A; León, Rolando J C; Schuenemann, Verena J; Weigel, Detlef; Botto, Javier F

2017-07-01

The growing collection of sequenced or genotyped Arabidopsis thaliana accessions includes mostly individuals from the native Eurasian and N. African range and introduced North American populations. Here, we describe the genetic and phenotypic diversity, along with habitats and life history, of A. thaliana plants collected at the southernmost end of its worldwide distribution. Seed samples were harvested from plants growing in four sites within a ~3500-km 2 -area in Patagonia, Argentina, and represent the first germplasm to be collected in South America for this species. Whole-genome resequencing revealed that plants from the four sites and a Patagonia herbarium specimen collected in 1967 formed a single haplogroup (Pat), indicating that the phenotypic variation observed in the field reflected plastic responses to the environment. admixture and principal components analyses suggest that the ancestor of the Pat haplogroup either came from Italy or the Balkan/Caucasus regions of Eurasia. In the laboratory, plants from the Pat haplogroup were hyposensitive to continuous red (Rc) and shade light, with corresponding changes in the expression of phytochrome signalling genes. Pat had higher PIF3 and PIF5 and lower HY5 expression under Rc light; and lower expression of PIL1, ATHB2 and HFR1 under shade compared to Col-0. In addition, Pat plants had a strong vernalization requirement associated with high levels of FLC expression. We conclude that including Pat in studies of natural variation and in comparison with other introduced populations will provide additional information for association studies and allow for a more detailed assessment of the demographic events following colonization. © 2017 John Wiley & Sons Ltd.

«Hay que argentinizar la Patagonia». Miradas sobre la Nación y la Ciudadanía en tiempos de cambio (1916-1930

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Ruffini, Martha

2011-12-01

Full Text Available The Goverment of Civic Radical Union (1916-1930 encourage politicals and socials transformations, that for the National territories could implyed a modification on its marginal politic. The expressions of the leadership supported this perception, but the concepts of Nation and citizenship were redefined as considering the Patagonia a place to argentinized. The argentinization was introduced as priority ,because of rural worker conflictivity,determinating the extension from politic rights to orders validity, security and social control.

El gobierno de la Unión Cívica Radical (1916-1930 alentó transformaciones políticas y sociales que para los Territorios Nacionales podían implicar la modificación de su marginalidad política. Las expresiones de la dirigencia avalaron esta percepción pero los conceptos de Nación y Ciudadanía fueron resignificados al pensar la Patagonia como espacio a «argentinizar». La argentinización del sur se presentó como prioridad debido a la conflictividad obrera-rural, condicionando la ampliación de los derechos políticos a la vigencia del orden, la seguridad y el control social.

Primer registro paleoparasitológico de Trichuris SP (nematoda, capilariidae en muestras asociadas a restos humanos del Holoceno tardío de Patagonia septentrional

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Fugassa, Martín H.

2009-01-01

Full Text Available En el marco de los estudios paleoepidemiológicos que se realizan en restos arqueológicos asignados a poblaciones de cazadores-recolectores de Patagonia, este trabajo presenta información novedosa acerca de la presencia de parásitos en muestras de sedimento de las cavidades pélvicas correspondientes a individuos que habitaron la costa norte de Patagonia durante el Holoceno Tardío. Fueron analizados 3 casos de diferente cronología y en dos de ellos, los de menor antigüedad relativa, los resultados fueron positivos para la presencia de Trichuris trichiura. Es interesante mencionar al respecto que para el período que involucra a los dos casos positivos, la información arqueológica registra un proceso de intensificación en el que se explota una mayor diversidad de fauna y se incrementan los artefactos de molienda en los sitios. Entre las posibles causas propuestas para este proceso se encuentran el aumento demográfico y/o el nucleamiento poblacional en espacios favorables que comienzan a saturarse, hecho consistente con la evidencia cultural obtenida al momento y con la presencia de Trichuris sp.

First South American Agathis (Araucariaceae), Eocene of Patagonia.

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Wilf, Peter; Escapa, Ignacio H; Cúneo, N Rubén; Kooyman, Robert M; Johnson, Kirk R; Iglesias, Ari

2014-01-01

Agathis is an iconic genus of large, ecologically important, and economically valuable conifers that range over lowland to upper montane rainforests from New Zealand to Sumatra. Exploitation of its timber and copal has greatly reduced the genus's numbers. The early fossil record of Agathis comes entirely from Australia, often presumed to be its area of origin. Agathis has no previous record from South America. We describe abundant macrofossils of Agathis vegetative and reproductive organs, from early and middle Eocene rainforest paleofloras of Patagonia, Argentina. The leaves were formerly assigned to the New World cycad genus Zamia. Agathis zamunerae sp. nov. is the first South American occurrence and the most complete representation of Agathis in the fossil record. Its morphological features are fully consistent with the living genus. The most similar living species is A. lenticula, endemic to lower montane rainforests of northern Borneo. Agathis zamunerae sp. nov. demonstrates the presence of modern-aspect Agathis by 52.2 mya and vastly increases the early range and possible areas of origin of the genus. The revision from Zamia breaks another link between the Eocene and living floras of South America. Agathis was a dominant, keystone element of the Patagonian Eocene floras, alongside numerous other plant taxa that still associate with it in Australasia and Southeast Asia. Agathis extinction in South America was an integral part of the transformation of Patagonian biomes over millions of years, but the living species are disappearing from their ranges at a far greater rate.

Reptile and rodent parasites in raptor pellets in an archaeological context: the case of Epullán Chica (northwestern Patagonia, Argentina)

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Beltrame, María Ornela; Fernández, Fernando Julián; Sardella, Norma Haydeé

2015-07-01

Paleoparasitology is the study of parasite remains from archaeological and paleontological sites. Raptor pellets can be used as source for paleoparasitological information in archaeological sites. However, this zooarchaeological material has been scarcely studied. Epullán Chica (ECh) is an archaeological site in northwestern Patagonia. This cave yielded remains from more than 2000 years before present. The aim of this paper was to study the parasite remains found in owl pellets from the archaeological site ECh, and to discuss the paleoparasitological findings in an archaeological context. Twenty two raptor pellets were examined for parasites. The pellets were whole processed by rehydration in a 0.5% water solution of trisodium phosphate, followed by homogenization, filtered and processed by spontaneous sedimentation. Eight out of 22 bird pellets examined were positive for parasites from reptiles and rodents. Representatives of 12 parasite taxa were recorded; nine of this parasitic species were reported for the first time from ancient samples from Patagonia. This is the first time that pellets give evidences of ancient reptile parasites from archaeological contexts. It is noteworthy that Late Holocene hunter-gatherers of the upper Limay River basin, could have been exposed to some of these zoonotic parasites. Future paleoparasitological studies on owl pellets may reflect even more the parasitological diversity of all micromammal and reptile species presents in ancient times.

Revisión de la distribución de Hyalella Smith, 1874 (Crustacea, Amphipoda) en la Patagonia e islas adyacentes

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De los Ríos-Escalante,Patricio; Mansilla,Andrés; Anderson,Christopher B

2012-01-01

Se realiza una revisión de las especies de anfípodos del género Hyalella en aguas continentales de la Patagonia, isla Tierra del Fuego, Reserva de la Biosfera de Cabo de Hornos e islas adyacentes (38-54°S). Esta zona austral presenta numerosos tipos de ambientes acuáticos continentales como lagos, humedales y arroyos, y las principales especies en ambientes bentónicos corresponden a anfípodos del género Hyalella. La bibliografía menciona la presencia de H. costera, H. chiloensis, H. falklande...

Is the prominent ericoid mycorrhizal fungus Rhizoscyphus ericae absent in the Southern Hemisphere’s Ericaceae? A case study on the diversity of root mycobionts in Gaultheria spp. from northwest Patagonia, Argentina

Czech Academy of Sciences Publication Activity Database

Brusone, M. C.; Fontenla, S. B.; Vohník, Martin

2015-01-01

Roč. 25, č. 1 (2015), s. 25-40 ISSN 0940-6360 R&D Projects: GA MŠk 7AMB12AR014 Institutional support: RVO:67985939 Keywords : ericoid mycorrhiza * Gaultheria * Patagonia Subject RIV: EF - Botanics Impact factor: 3.252, year: 2015

Condiciones productivas y exigencias de calidad en la fruticultura de la Patagonia argentina

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Belén Alvaro

2013-01-01

Full Text Available La producción alimentaria está regida, a partir de los años noventa, por requerimientos de calidad e inocuidad que modifican sustancialmente las condiciones productivas del eslabón primario, en el marco de una reestructuración del sistema agroalimentario mundial. El caso en estudio aborda la conformación social de la cadena frutícola localizada en el norte de la Patagonia argentina, donde estos requerimientos se formalizan, entre otros, en las buenas prácticas agrícolas, abordadas como dispositivos de control que interpelan y vuelven complejas las condiciones de reproducción social de los chacareros, como productores independientes en la cadena, con impactos en sus trayectorias vitales y productivas. Se consultaron fuentes secundarias, y se realizó el relevamiento primario de casos. Las conclusiones se inscriben en las tensiones entre configuraciones productivas locales y avances de los controles del capital concentrado.

Efectos de la instalación de un gasoducto sobre algunas propiedades del suelo superficial y la cobertura vegetal en el NE de Chubut Gas-pipeline installation effects on superficial soil properties and vegetation cover in Northeastern Chubut

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Esteban Kowaljow

2008-07-01

Full Text Available En este trabajo describimos el impacto del tendido de un gasoducto y de la reposición parcial del material removido, sobre algunas propiedades físicas y químicas del suelo y sobre la cobertura vegetal en tres sitios ecológicos del nordeste de Chubut. En cada sitio se identificaron 4 zonas diferentes: zona 1, faja desmontada y compactada por el tránsito de maquinaria pesada; zona 2, faja desmontada, con posterior reposición del suelo y la vegetación removidos; y otras dos zonas correspondientes a la estepa adyacente no disturbada: montículos asociados a arbustos y espacios entre montículos. Los mayores valores de densidad aparente se encontraron en los suelos de la zona 1 y en los del entremontículo (1,43 Mg m-3. La resistencia a la penetración fue significativamente mayor en las zonas 1 y 2, ambas zonas presentaron valores de resistencia a la penetración superiores a 1 MPa. La tasa de infiltración fue mucho mayor en el montículo (261 mm h-1 que en el resto de las zonas. La velocidad de infiltración de la zona 2 (85 mm h-1 fue mayor a la de la zona 1 (35 mm h-1 y el entremontículo (50 mm h-1. Los contenidos de carbono orgánico y nitrógeno de los suelos de las zonas 1 y 2 fueron similares a los del entremontículo y significativamente inferiores a los del montículo, excepto en la zona 2 de uno de los sitios ecológicos. La remoción de la vegetación y el suelo superficial, y el posterior tránsito de maquinaria pesada durante la instalación del gasoducto produjeron un fuerte impacto sobre las propiedades físicas del suelo. La mayor limitación de los suelos disturbados fue su baja capacidad para incorporar agua, derivada principalmente de su elevada compactación y baja porosidad, lo que explicaría en parte la lenta recuperación de la cobertura vegetal en la zona 1. En ninguno de los tres sitios estudiados, la reposición del material removido por la actividad del desmonte significó una medida de recuperación eficaz

Timing of the deglaciation in southern Patagonia: Testing the applicability of K-Feldspar IRSL

DEFF Research Database (Denmark)

Blomdin, Robin; Murray, Andrew S.; Thomsen, Kristina Jørkov

2012-01-01

need evaluation against an absolute chronology. The aim of this project is to investigate the applicability of OSL dating to sediments from southern Patagonia; in particular, we examine the dating potential of K-feldspar IRSL signals. Samples were collected from landforms interpreted as being deposited...... to our individual dose estimates based on the over-dispersion (OD) observed in laboratory gamma dose recovery experiments (22% for small aliquots and 18% for single grains). Then the possible effects of incomplete bleaching and differential fading are examined. For our natural samples we observe...... environmental ODs between 30 and 130% and mean residual doses between ∼30 and 80 Gy. Minimum age models are used to identify the part of the dose population that is most likely to have been well-bleached and results from these models are compared. The models give ages that are consistent with each other...

High Resolution Land Surface Modeling over the NEF Basin in the Chilean Patagonia

Science.gov (United States)

Somos-Valenzuela, M. A.

2017-12-01

Stakeholders and policy makers perceive that water and climate change adaptation are among the most vulnerable issues that need to be addressed. Therefore, there is a need not only from the scientific community but also from the society to use integrated methodologies that link advances in climatology with hydrology to provide data that helps us to provide adaptation strategies. The Andes and the Chilean-Argentinean Patagonia have been steadily warming up to 0.5 Celsius degrees per decades at the same time that precipitation is decreasing by 10 to 12 % per decade. In the future is expected that these trends will continue which will have impacts in the annual water budget. The Chilean Patagonia has brought a lot of attention during last decade because two hydroelectric project seek to build dams in one of the most pristine environments in the world. Also, in the Baker River basin a series of Glacier Lakes Outburst Flood have occurred which is perceived as an undeniable consequence of the effects of climate change in the glacier system. Major attention is mainly situated in the impact of climate change in glaciers contribution to sea level rise, GLOF studies given the numerous supra glacier lakes that are forming, and the study of stream flow point observation. The objectives of this research are: 1) Study the historical trends of precipitation, temperature, land cover changes and streamflow available in the Baker Basin; 2) Use a couple glacier model with a land surface model to predict the evolution of glaciers and their effects in the water availability. To address these objectives, I will analyze trends in hydro meteorology observations and correlation with trends in Land Cover Changes. Use the WRF-hydro framework to generate data in a small watershed that will allow to calibrate a high resolution hydro glaciology model to understand the partition between glaciered and non-glaciered runoff. The parameters estimated in the small domain could have the potential to

Unravelling the collapse mechanisms at a Jurassic caldera of the Chon Aike silicic LIP in Southern Patagonia (47 deg. 15 'S, 71 deg. 40'W), Argentina

International Nuclear Information System (INIS)

Sruoga, P; Japas, S; Salani, F; Kleiman, L; Graffigna, M

2008-01-01

La Peligrosa Caldera is located at Sierra Colorada (47 0 15'S, 71 0 40' W) in the Chon-Aike silicic LIP. It represents an unique window to understand the eruptive mechanisms that prevailed throughout the ignimbritic flare-up in Southern Patagonia during middle to late Jurassic times. Key pieces of lithologic and structural evidences are taken into account to reconstruct the volcanic structure.

Unravelling the collapse mechanisms at a Jurassic caldera of the Chon Aike silicic LIP in Southern Patagonia (47° 15 'S, 71° 40'W), Argentina

Science.gov (United States)

Sruoga, P.; Japas, S.; Salani, F.; Kleiman, L.; Graffigna, M.

2008-10-01

La Peligrosa Caldera is located at Sierra Colorada (47° 15'S, 71° 40' W) in the Chon-Aike silicic LIP. It represents an unique window to understand the eruptive mechanisms that prevailed throughout the ignimbritic flare-up in Southern Patagonia during middle to late Jurassic times. Key pieces of lithologic and structural evidences are taken into account to reconstruct the volcanic structure.

Application of DNA forensic techniques for identifying poached guanacos (Lama guanicoe) in Chilean Patagonia*.

Science.gov (United States)

Marín, Juan C; Saucedo, Cristian E; Corti, Paulo; González, Benito A

2009-09-01

Guanaco (Lama guanicoe) is a protected and widely distributed ungulate in South America. A poacher, after killing guanacos in Valle Chacabuco, Chilean Patagonia, transported and stored the meat. Samples were retrieved by local police but the suspect argued that the meat was from a horse. Mitochondrial cytochrome b gene (774 pb), 15 loci microsatellites, and SRY gene were used to identify the species, number of animals and their population origin, and the sex of the animals, respectively. Analysis revealed that the samples came from a female (absence of SRY gene) Patagonian guanaco (assignment probability between 0.0075 and 0.0282), and clearly distinguishing it from sympatric ungulates (E-value = 0). Based on the evidence obtained in the field in addition to forensic data, the suspect was convicted of poaching and illegally carrying fire arms. This is the first report of molecular tools being used in forensic investigations of Chilean wildlife indicating its promising future application in guanaco management and conservation.

Geomorphological evidences of Quaternary tectonic activities in the Santa Cruz river valley, Patagonia, Argentina

International Nuclear Information System (INIS)

Massabie, A.; Sanguinetti, A.; Nestiero, O.

2007-01-01

From Argentin lake, at west on Andean hills, to Puerto Santa Cruz on Atlantic coast, Santa Cruz river cross eastward Santa Cruz province over 250 km in Patagonia at southern Argentina. Present bed of the river has a meandering outline with first order meanders of great ratio bends and second order meanders of minor ratio bends. Principal wanderings are 45 to 55 km spaced from near Estancia La Julia or Rio Bote at west to Comandante Luis Piedrabuena at east. On river's bed middle sector these great curvatures are located at Estancia Condor Cliff and Estancia Rincon Grande. Regional and partial detailed studies allow to recognize structural control on river's bed sketch and valley s geomorphology that relates first order bends with reactivated principal faults. These faults fit well with parallel system of northwest strike of Austral Basin.On geological, geomorphologic and structural evidences recognized in Santa Cruz river, quaternary tectonic activity, related to Andean movements in southern Patagonian foreland, is postulated. (author)

Geology and Conceptual Model of the Domuyo Geothermal Area, Patagonia, Argentina

Science.gov (United States)

Fragoso, A. S.; Ferrari, L.; Norini, G.

2017-12-01

Cerro Domuyo is the highest mountain in Patagonia and its western slope is characterized by thermal springs with boiling fluids as well as silicic domes and pyroclastic deposits that suggest the existence of a geothermal reservoir. Early studies proposed that the thermal springs were fault-controlled and the reservoir was located in a graben bounded by E-W normal faults. A recent geochemical study estimated a temperature of 220ºC for the fluid reservoir and a thermal energy release of 1.1 GW, one of the world largest advective heat flux from a continental volcanic center. We carried out a geologic survey and U-Pb and U-Th geochronologic study to elaborate an updated conceptual model for the Domuyo geothermal area. Our study indicates that the Domuyo Volcanic Complex (DVC) is a dome complex overlying an older, Middle Miocene to Pliocene volcanic sequence widely exposed to the southwest and to the north, which in turn covers: 1) the Jurassice-Early Creteacoeus Neuquen marine sedimentary succession, 2) silicic ignimbrites dated at 186.7 Ma and, 3) the Paleozoic metamorphic basement intruded by 288 Ma granite bodies. These pre-Cenozoic successions are involved in dominantly N-S trending folds and thrust faults later displaced by E-W striking normal faults with a right lateral component of motion that underlie the DVC. The volcanic cycle forming the DVC is distinctly bimodal with the emplacement of massive silicic domes but also less voluminous olivine basalts on its southern slope. The central dome underwent a major collapse that produced 0.35 km3 of ash and block flow and associated pyroclastic flows that filled the valley to the southwest up to 30 km from the source. This was followed by a voluminous effusive activity that formed silicic domes dated between 254-322 Ky, which is inferred to overlain a partially molten silicic magma chamber. Integrating the geologic model with magnetotelluric and gravity surveys we developed a conceptual model of the geothermal system

Desarrollo de un proyecto agrícola en la región marginal de la Patagonia Meridional Argentina. El caso de Gobernador Gregores

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María Eugenia Cepparo de Grosso

2012-02-01

Full Text Available Santa Cruz, provincia ubicada en el extremo sur del territorio continental argentino, posee un ambiente fuertemente condicionado por la fragilidad de sus características naturales y una situación socioeconómica tradicionalmente orientada a la monoactividad ganadera en el área rural y a los servicios públicos en los centros urbanos. En ese marco, y durante la década de 1990, surgió una iniciativa apoyada por organismos del Estado y financiada por bancos provinciales para estimular un proyecto agrícola adaptado a las limitadas aptitudes agrícolas de la región. Un reducido número de agricultores, inquietos por generar actividades que diversificaran el tradicional modelo pastoril, experimentaron los dilemas de los comienzos y las crisis de un proyecto de estímulo económico en un territorio marginal. Este trabajo contribuye con una serie de reflexiones acerca de las motivaciones que justifican el estudio de pequeñas sociedades en áreas marginales; de la confrontación entre el marco conceptual de la marginalidad según los países centrales y los periféricos; y del accionar y el compromiso de los actores sociales motivados por una alternativa de desarrollo local en una localidad ubicada en el centro de la Patagonia Meridional Argentina.

Gamma irradiation as a phytosanitary treatment for fresh pome fruits produced in Patagonia

Science.gov (United States)

Pérez, J.; Lires, C.; Horak, C.; Pawlak, E.; Docters, A.; Kairiyama, E.

2009-07-01

Argentina produces 1.8 million tons/year of apples ( Malus domestica L.) and pears ( Pyrus communis L.) in the Patagonia region. Cydia pomonella, codling moth, and Grapholita molesta, Oriental fruit moth, ( Lepidoptera: Tortricidae) are quarantine pests in pome fruits. Irradiation is a promising phytosanitary treatment because a dose of 200 Gy completely prevents pest adult emergence. A pilot irradiation process of commercially packaged 'Red Delicious' apples and 'Packham's Triumph' pears was performed in an irradiation facility with a Cobalt 60 source. Quality analyses were carried out at 0, 2, 4, 6 and 8 months of storage (1 °C, RH 99%) to evaluate fruit tolerance at 200, 400 and 800 Gy. Irradiation at 200 and 400 Gy had no undesirable effects on fruit quality (pulp firmness, external colour, soluble solids content (SSC), titratable acidity (TA) and sensory evaluations). Irradiation of 'Red Delicious' apples and 'Packham's Triumph' pears can be applied as a commercial quarantine treatment with a minimum absorbed dose of 200 Gy (to control codling moth and Oriental fruit moth) and <800 Gy (according to quality results).

Fouling community dominated by Metridium senile (Cnidaria: Anthozoa: Actiniaria in Bahía San Julián (southern Patagonia, Argentina

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Juan Pablo Martin

2015-06-01

Full Text Available The objective of this study is to provide information about a harbour-fouling community dominated by Metridium senile in southern Patagonia. Several steel tubes from the wharf of Puerto San Julián were extracted to perform repair tasks, allowing the attached benthic community to be studied. Sampling was conducted at three levels: lower intertidal, 3-4 m depth and 6-7 m depth. In the lower intertidal, M. senile had a relative abundance of 43%, the most abundant accompanying species being Perumytilus purpuratus, Mytilus edulis platensis and Aulacomya atra atra. At subtidal level, the anemone showed relative abundances of 64% and 65%, and was accompanied by Monocorophium insidiosum at 3-4 m depth and by polychaetes of families Sabellidae and Syllidae at 6-7 m at depth. In the lower intertidal, epibiosis was more frequent on P. purpuratus, A. atra atra and M. edulis platensis, while in the subtidal, the richness of substrate-organisms increased significantly and the anemone was fixed to A. atra atra, M. edulis platensis, Paramolgula gregaria, Crepipatella dilatata, Austromegabalanus psittacus, Hiatella arctica, Polyzoa opuntia, Pyura sp. and Sabellidae tubes. The ability of M. senile to settle on many different organisms, along with other strategies, makes it a colonizer able to displace other species that could compete with it for substratum. Given the cosmopolitan nature of M. senile, the fact that this species has not been previously reported in the coastal zone of the region, and the results of our study, we discuss the possibility that this sea anemone is an invasive alien species in southern Patagonia, or at least a cryptogenic species.

The role of natural mineral particles collected at one site in Patagonia as immersion freezing ice nuclei

Science.gov (United States)

López, María Laura; Borgnino, Laura; Ávila, Eldo E.

2018-05-01

This work studies the role of mineral particles collected in the region of Patagonia (Neuquén, Argentina) as ice nuclei particles (INPs) by immersion freezing mode. The particle immersion-freezing ability was analyzed under laboratory conditions by using an established drop-freezing technique. Mineralogical composition was characterized by using X-ray diffraction and electron micro probe analysis. Dynamic light scattering was used to determine the grain size distribution of particles, while the N2 adsorption and methylene blue adsorption methods were applied to determine their specific surface area. Water droplets of different volumes containing different concentrations of particles were cooled until droplets were frozen. For all the analyzed drop volumes, an increase in the freezing temperature of the drops was observed with increasing dust concentration. In the same way, the freezing temperature increased when the drop volume was increased at constant dust concentration. Both behaviors were linked to the availability of active sites in the particles. A plateau in the freezing temperature was observed at high suspension concentration for all the drop volumes. This plateau was related to the aggregation of the particles when the suspension concentration was increased and to the consequent decrease in the number of active sites. The active sites per unit of surface area were calculated and reported. For the studied range of temperature, results are in agreement with those reported for different sites and particles. From the chemical and morphological analysis of the particle components and the results obtained from the literature, it was concluded that even though montmorillonite was the main mineral in the collected sample, the accessory minerals deserve to be analyzed in detail in order to know if they could be responsible for the ability of the collected soil particles to act as INPs. Considering that the region of Patagonia has been identified as an important

Análisis de la diversidad biológica y mestizaje en la ciudad de Puerto Madryn (Prov. de Chubut, Argentina

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Parolín, María Laura

2013-12-01

Full Text Available En el marco del estudio de la composición genética de las poblaciones cosmopolitas de Argentina, se analizó una muestra poblacional de la localidad de Puerto Madryn (PM con la finalidad de evaluar su diversidad biológica mediante la utilización de marcadores biparentales y uniparentales y comparar los resultados con los obtenidos previamente por nuestro equipo de investigación en seis poblaciones cosmopolitas de distintas regiones de la Argentina, aunque poniendo el énfasis en las correspondientes a la Región Patagónica.Las muestras biológicas fueron tomadas con consentimiento informado a 82 dadores de sangre no emparentados que concurrieron al Banco de Sangre y al Hospital Subzonal de dicha localidad, a quienes también se les realizó una encuesta genealógica. A partir de los datos proporcionados por los marcadores autosómicos, se registró una contribución europea de 67.2%, amerindia de 29.4% y africana de 3.4%. A un origen amerindio fueron adscriptos el 59.9% y 8.7% de los linajes maternos y paternos, respectivamente, revelando un desigual aporte autóctono por género.El aporte europeo se vio representado principalmente por el Hg H (19.5% y se detectaron sólo dos linajes subsaharianos.En PM las migraciones desde el centro del país han generado un fuerte impacto, reflejado en la mayor contribución de marcadores europeos respecto de dos muestras estudiadas previamente en Chubut (Comodoro Rivadavia y Esquel. Estas diferencias al interior de una misma provincia nos advierten que no puede abordarse el análisis de la constitución genética de las poblaciones sin dar cuenta de las particularidades regionales.

Checklist of the Discomycetes (Fungi of Patagonia, Tierra del Fuego and adjacent antarctic areas

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Irma J. Gamundí

2004-01-01

Full Text Available La información brindada en este catálogo consiste en registrar las especies de hongos pertenecientes a los órdenes Cyttariales, Helotiales, Ostropales, Pezizales, Rhytismatales y Thelebolales (Discomycetes coleccionadas en Patagonia, Tierra del Fuego y áreas adyacentes antárticas (Patagonia. Además datos sobre sus organismos asociados fueron localizados, resumidos, validados y editados. Las fuentes de información fueron las exsiccatae depositadas en colecciones de Argentina y otros países y de las publicaciones listadas en la bibliografía. Otros registros derivaron de observaciones de campo sobre material fresco y colecciones de referencia. La información fue acumulada en un sistema computarizado relacional de datos taxonómicos, nomenclaturales, bibliográficos, de distribución geográfica y de observaciones biológicas. Este sistema permite la acumulación de datos paralelos en diferentes idiomas, y distingue la información original de la opinión corriente de lo que puede significar esa información. En la Biological Records Database, 5029 registros fueron creados para observaciones sobre la ocurrencia temporal y espacial de los organismos vivos de la región. De éstos, 2613 corresponden a registros de colecciones de Discomycetes de la Patagonia y Tierra del Fuego, con la siguiente distribución: 1854 para a la Argentina, 687 para Chile y 72 para áreas adyacentes antárticas. Excluyendo los sinónimos, los Discomycetes están representados por 361 especies y taxones subespecíficos (160 géneros, 22 familias y 7 órdenes. Los registros remanentes fueron de organismos asociados con los Discomycetes: 163 animales (8 especies, 8 géneros, 6 familias y 5 órdenes; 2 Chromista; 223 hongos (52 especies, 54 géneros, 26 familias y 13 ódenes; 2028 plantas (159 especies, 122 géneros, 59 familias y 39 órdenes. Cada uno de estos taxones (y cada sinónimo conocido está representado por un registro separado en la Base de Datos Taxon

Spatial distribution of volcanic ash deposits of 2011 Puyehue-Cordón Caulle eruption in Patagonia as measured by a perturbation in NDVI temporal dynamics

Science.gov (United States)

Easdale, M. H.; Bruzzone, O.

2018-03-01

Volcanic ash fallout is a recurrent environmental disturbance in forests, arid and semi-arid rangelands of Patagonia, South America. The ash deposits over large areas are responsible for several impacts on ecological processes, agricultural production and health of local communities. Public policy decision making needs monitoring information of the affected areas by ash fallout, in order to better orient social, economic and productive aids. The aim of this study was to analyze the spatial distribution of volcanic ash deposits from the eruption of Puyehue-Cordón Caulle in 2011, by identifying a sudden change in the Normalized Difference Vegetation Index (NDVI) temporal dynamics, defined as a perturbation located in the time series. We applied a sparse-wavelet transform using the Basis Pursuit algorithm to NDVI time series obtained from the Moderate Resolution Image Spectroradiometer (MODIS) sensor, to identify perturbations at a pixel level. The spatial distribution of the perturbation promoted by ash deposits in Patagonia was successfully identified and characterized by means of a perturbation in NDVI temporal dynamics. Results are encouraging for the future development of a new platform, in combination with data from forecasting models and tracking of ash cloud trajectories and dispersion, to inform stakeholders to mitigate impact of volcanic ash on agricultural production and to orient public intervention strategies after a volcanic eruption followed by ash fallout over a wide region.

Paleoecología: el uso de los quironómidos fósiles (Diptera: Chironomidae en reconstrucciones paleoambientales durante el Cuaternario en la Patagonia Paleoecology: the use of fossil chironomids (Diptera: Chironomidae for paleoenvironmental reconstructions in Patagonia

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Julieta Massaferro

2009-06-01

Full Text Available Entre los indicadores biológicos lacustres más utilizados en las reconstrucciones ambientales, se encuentran el polen, los ostrácodos y las diatomeas, y entre los insectos, los coleópteros y los quironómidos. Este grupo ha cobrado gran importancia en los últimos tiempos, debido a los resultados prometedores que se han obtenido en reconstrucciones climáticas realizadas en América del Norte y Europa. En América del Sur, el uso de los quironómidos fósiles en estudios cuaternarios es relativamente limitado, principalmente por su escaso conocimiento taxonómico regional. La mayor parte de estos estudios fueron realizados en lagos glaciares patagónicos de Argentina y Chile. Las larvas de quironómidos constituyen una valiosa herramienta paleolimnológica, por ser un grupo de organismos altamente sensible a cambios ambientales, tanto naturales como artificiales. Además, es un grupo de insectos ampliamente distribuido y con una abundancia y diversidad relativamente altas. Sus cápsulas cefálicas se preservan en los sedimentos lacustres y poseen caracteres importantes que permiten identificar géneros y muchas veces especies. El estudio de los ensambles de quironómidos en sedimentos lacustres puede ser utilizado con distintos objetivos, por ejemplo, para estudios de eutrofización, ya que responden rápidamente a cambios en la concentración de nutrientes, materia orgánica y otros elementos, como metales pesados. No obstante, uno de los potenciales más importantes de este grupo de insectos es su sensibilidad a los cambios de temperatura, por este motivo, la aplicación más importante de su estudio en sedimentos se centra en las reconstrucciones climáticas. Esta contribución es una síntesis de los resultados de los trabajos publicados en la Patagonia argentina y chilena, sobre la base del uso de los quironómidos fósiles en reconstrucciones paleoambientales.Pollen, ostracods, diatoms and insects such as beetles and chironomids are

The sea anemone Bunodactis octoradiata (Anthozoa: Actiniaria from southern Patagonia: morphological study and new records

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Agustín Garese

2014-10-01

Full Text Available Bunodactis Verril, 1899 comprises at present 19 nominal species of sea anemones. The validity of the genus is under discussion. The description of the species, Bunodactis octoradiata Carlgren, 1899, is insufficient for reliable identification, and although subsequent works have provided additional information on the species, its description still needs to be complemented. Herein we describe B. octoradiata based on histological sections of the internal anatomy, and give a complete and detailed description of the external anatomy. The cnidom is composed of spirocysts, basitrichs and microbasic p-mastigophores; their distribution in the organism, sizes and relative abundances are provided. The presence of zooxanthellae is reported for the first time. Bunodactis octoradiata is distributed in groups that vary from 5.6 to 45 ind./m² in the field. Additionally, our data extends the distribution of the species along the coast of southern Patagonia (47°44'36"-49°15'13"S and 65°50'26"-67°39'45"W.

Unravelling the collapse mechanisms at a Jurassic caldera of the Chon Aike silicic LIP in Southern Patagonia (47 deg. 15 'S, 71 deg. 40'W), Argentina

Energy Technology Data Exchange (ETDEWEB)

Sruoga, P [CONICET-SEGEMAR. Av. J. A. Roca 651. Buenos Aires (Argentina); Japas, S; Salani, F [CONICET-UBA. Depto. Cs. Geologicas, Pabellon II, Ciudad Universitaria, C1428EHA, Buenos Aires (Argentina); Kleiman, L [Gerencia de Exploration de Materias Primas, Comision Nacional de EnergIa Atomica, Avda. del Libertador 8250, 1419, Buenos Aires (Argentina); Graffigna, M [Universidad Nacional de San Juan (Argentina)], E-mail: patysruoga@yahoo.com.ar, E-mail: msjapas@gl.fcen.uba.ar, E-mail: fms@gl.fcen.uba.ar, E-mail: kleiman@cae.cnea.gov.ar

2008-10-01

La Peligrosa Caldera is located at Sierra Colorada (47{sup 0} 15'S, 71{sup 0} 40' W) in the Chon-Aike silicic LIP. It represents an unique window to understand the eruptive mechanisms that prevailed throughout the ignimbritic flare-up in Southern Patagonia during middle to late Jurassic times. Key pieces of lithologic and structural evidences are taken into account to reconstruct the volcanic structure.

Spatial dynamics of Fabiana imbricata shrublands in northwestern Patagonia in relation to natural fires

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L. Ghermandi

2010-05-01

Full Text Available Fire is a critical disturbance in the structuring and functioning of most Mediterranean ecosystems. In northwestern Patagonia, vegetation patterns are strongly influenced by fire and environmental heterogeneity. Dendroecology, together with satellite imagery and GIS, have been demonstrated to be useful tools in studies that relate to fire effects with patches, patterns and species dynamics at landscape scale. Such studies can be approached from landscape ecology, which has evolved in the last years supported by the development of remote sensing and GIS technologies. This study evaluates the spatial dynamic of F. imbricata in response to fire using remote sensing, GIS and dendrochronology techniques, at landscape scale. Two sites were evaluated and one of them was affected by fire in the year 1999. The digital processing images (using the NBR spectral index and the dendroecological analysis verified this. A fire, occurring in 1978, was also detected by the analysis of F. imbricata growth rings. The relation between F. imbricata shrubland dynamics and spatial configuration with fire, land topography and hydrography was established in the study area.

Inter-subjectivity and Domestication in the Making of a Global Region: Territorialization of Salmon in the Chilean Patagonia

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Gustavo Blanco Wells

2016-01-01

Full Text Available This article examines transformations in the Chilean Patagonia, a region that has become a world leader in Salmon production for global markets. Employing ethnographic methods, this study examines the possibilities of considering inter-subjectivities in the processes of conforming important regions in the global production of foods in contrast to some perspectives that emphasize inter-objectivity in analyzing human and non-human relations. In a complex and globalized world, assembly theory permits us to understand how forms of bio-power stimulate regional transformations that then generate new relationships between life, agency and nature. The analysis focuses on experiments, encounters and affects, decentering conventional perspectives about the domestication of species, regional development and food production. It opens a debate about the potentialities and limits of non-lineal interpretations of reality.

UNA CONCEPTUALIZACIÓN ACERCA DE LA CRONOLOGÍA DE LAS ESTACIONES ENTRE LOS TEHUELCHES DEL EXTREMO SUR DE PATAGONIA

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Fabián Arias

2006-12-01

Full Text Available El presente trabajo intenta repasar un conjunto de categorías lingüísticas por medio de las cuales los tehuelches de la Patagonia austral significaron distintos ciclos cronológicos que se sucedían en el transcurso del año. Estos períodos remitían a fenómenos de índole natural que afectaron la cotidianeidad de las tolderías y determinaron, durante mucho tiempo, las condiciones en las que se organizó el poblamiento regional. Son justamente esas circunstancias las que se van a ver cada vez más intermediadas a partir de la incorporación del caballo, sucedida en el extremo sur, hacia la mitad del siglo XVIII.

Caracterización y modelación del transporte preferencial de plaguicidas organofosforados en suelos productivos bajo riego. Aplicación al Distrito Colonia Centenario, Patagonia Argentina.

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DUFILHO, ANA CECILIA AMALIA

2016-01-01

[EN] In this thesis, transport and fate of organophosphate pesticides - azinphos-methyl and chlorpyrifos- in productive soils from the valley of the Neuquén River in the Patagonia Argentina are analysed. Climate of the region is arid, so traditional fruit production is under flood irrigation. The soils in the floodplain are predominant Aridisols with textures from sandy loam to clay loam. Methodologically, the thesis was based on: field experiments and data and information processing condu...

Larval fish feeding ecology, growth and mortality from two basins with contrasting environmental conditions of an inner sea of northern Patagonia, Chile.

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Landaeta, Mauricio F; Bustos, Claudia A; Contreras, Jorge E; Salas-Berríos, Franco; Palacios-Fuentes, Pámela; Alvarado-Niño, Mónica; Letelier, Jaime; Balbontín, Fernando

2015-05-01

During austral spring 2011, a survey was carried out in the inland sea (41°30'-44°S) of north Patagonia, South Pacific, studying a northern basin (NB: Reloncaví Fjord, Reloncaví Sound and Ancud Gulf) characterized by estuarine regime with stronger vertical stratification and warmer (11-14 °C) and most productive waters, and a southern basin (SB: Corcovado Gulf and Guafo mouth), with more oceanic water influence, showed mixed conditions of the water column, colder (11-10.5 °C) and less productive waters. Otolith microstructure and gut content analysis of larval lightfish Maurolicus parvipinnis and rockfish Sebastes oculatus were studied. Larval M. parvipinnis showed similar growth rates in both regions (0.13-0.15 mm d(-1)), but in NB larvae were larger-at-age than in SB. Larval S. oculatus showed no differences in size-at-age and larval growth (0.16 and 0.11 mm d(-1) for NB and SB, respectively). M. parvipinnis larvae from NB had larger number of prey items (mostly invertebrate eggs), similar total volume in their guts and smaller prey size than larvae collected in SB (mainly calanoid copepods). Larval S. oculatus had similar number, volume and body width of prey ingested at both basins, although prey ingestion rate by size was 5 times larger in NB than in SB, and prey composition varied from nauplii in NB to copepodites in SB. This study provides evidence that physical-biological interactions during larval stages of marine fishes from Chilean Patagonia are species-specific, and that in some cases large size-at-age correspond to increasing foraging success. Copyright © 2015 Elsevier Ltd. All rights reserved.

A multi-decadal remote sensing study on glacial change in the North Patagonia Ice Field Chile

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Tetteh, Lucy Korlekwor

Glaciers in the North Patagonian Ice Fields are temperate glaciers and can be studied to understand the dynamics of climate change. However, the ice field has been neglected in mass balance studies. In this study, multi decadal study of glacial mass balance, glacier retreat and glacial lake expansion in the North Patagonia were studied. Landsat (TM, ETM+ and 8) and ASTER images were used. San Quintin glacier experienced the highest retreat. Demarcation of glacier lakes boundaries indicated an increase in glacial lake area an addition of 4 new glacial lakes. Nef glacier recorded the highest mass gain of 9.91 plus or minus 1.96 m.w.e.a.-1 and HPN-4 glacier recorded the highest mass loss of -8.9 plus or minus 1.96 m.w.e.a. -1. However, there is a high uncertainty in the elevation values in the DEM due to the rugged nature of the terrain and presence of the heavy snow cover.

Marine pollution effects on the southern surf crab Ovalipes trimaculatus (Crustacea: Brachyura: Polybiidae) in Patagonia Argentina.

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Lezcano, Aníbal Hernán; Rojas Quiroga, María Laura; Liberoff, Ana Laura; Van der Molen, Silvina

2015-02-28

We compared the carapace shape and thickness as well as the energy density of Ovalipes trimaculatus inhabiting areas comprising a gradient of marine pollution: high, moderate and undetected, in the Nuevo gulf (Patagonia Argentina). The carapace shape was evaluated by means of individual asymmetry scores (=fluctuating asymmetry) whereas the carapace thickness was assessed by measuring the carapace dry weight. The energy density was analyzed through its negative relationship with water content in muscle tissue. The individual asymmetry scores as well as the percentage of water content in muscle tissue were proportional to the marine pollution gradient, whereas the carapaces thickness did not differ among sampling sites. Our results are consistent with previous findings and demonstrate the direct effect of marine pollution on other taxa different from gastropods, cephalopods and polyplacophora and add to long-standing concerns about detrimental effects caused by marine pollution on the benthic community of the Nuevo gulf. Copyright © 2014 Elsevier Ltd. All rights reserved.

CO2 and CH4 fluxes of contrasting pristine bogs in southern Patagonia (Tierra del Fuego, Argentina)

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Münchberger, Wiebke; Blodau, Christian; Kleinebecker, Till; Pancotto, Veronica

2015-04-01

South Patagonian peatlands cover a wide range of the southern terrestrial area and thus are an important component of the terrestrial global carbon cycle. These extremely southern ecosystems have been accumulating organic material since the last glaciation up to now and are - in contrast to northern hemisphere bogs - virtually unaffected by human activities. So far, little attention has been given to these pristine ecosystems and great carbon reservoirs which will potentially be affected by climate change. We aim to fill the knowledge gap in the quantity of carbon released from these bogs and in what controls their fluxes. We study the temporal and spatial variability of carbon fluxes in two contrasting bog ecosystems in southern Patagonia, Tierra del Fuego. Sphagnum-dominated bog ecosystems in Tierra del Fuego are similar to the ones on the northern hemisphere, while cushion plant-dominated bogs can almost exclusively be found in southern Patagonia. These unique cushion plant-dominated bogs are found close to the coast and their occurrence changes gradually to Sphagnum-dominated bogs with increasing distance from the coast. We conduct closed chamber measurements and record relevant environmental variables for CO2 and CH4 fluxes during two austral vegetation periods from December to April. Chamber measurements are performed on microforms representing the main vegetation units of the studied bogs. Gas concentrations are measured with a fast analyzer (Los Gatos Ultraportable Greenhouse Gas Analyzer) allowing to accurately record CH4 fluxes in the ppm range. We present preliminary results of the carbon flux variability from south Patagonian peat bogs and give insights into their environmental controls. Carbon fluxes of these two bog types appear to be highly different. In contrast to Sphagnum-dominated bogs, cushion plant-dominated bogs release almost no CH4 while their CO2 flux in both, photosynthesis and respiration, can be twice as high as for Sphagnum

Root proliferation in native perennial grasses of arid Patagonia, Argentina

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Yanina A. TORRES; Mara M. MUJICA; Sandra S. BAIONI; Jos ENTO; Mara N. FIORETTI; Guillermo TUCAT; Carlos A. BUSSO; Oscar A. MONTENEGRO; Leticia ITHURRART; Hugo D. GIORGETTI; Gustavo RODRGUEZ; Diego BENTIVEGNA; Roberto E. BREVEDAN; Osvaldo A. FERNNDEZ

2014-01-01

Pappophorum vaginatum is the most abundant C4 perennial grass desirable to livestock in rangelands of northeastern Patagonia, Argentina. We hypothesized that (1) defoliation reduce net primary productivity, and root length density and weight in the native species, and (2) root net primary productivity, and root length density and weight, are greater in P. vaginatum than in the other, less desirable, native species (i.e., Aristida spegazzinii, A. subulata and Sporobolus cryptandrus). Plants of all species were either exposed or not to a severe defoliation twice a year during two growing seasons. Root proliferation was measured using the cylinder method. Cylindrical, iron structures, wrapped up using nylon mesh, were buried diagonally from the periphery to the center on individual plants. These structures, initially filled with soil without any organic residue, were dug up from the soil on 25 April 2008, after two successive defoliations in mid-spring 2007. During the second growing season (2008-2009), cylinders were destructively harvested on 4 April 2009, after one or two defoliations in mid-and/or late-spring, respectively. Roots grown into the cylinders were obtained after washing the soil manually. Defoliation during two successive years did reduce the study variables only after plants of all species were defoliated twice, which supported the first hypothesis. The greater root net primary productivity, root length den-sity and weight in P. vaginatum than in the other native species, in support of the second hypothesis, could help to explain its greater abundance in rangelands of Argentina.

Reconstruction of a glacial lake outburst flood (GLOF) in the Engaño Valley, Chilean Patagonia: Lessons for GLOF risk management.

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Anacona, Pablo Iribarren; Mackintosh, Andrew; Norton, Kevin

2015-09-15

Floods from moraine-dammed lake failures can have long standing effects not only on riverine landscapes but also on mountain communities due to the high intensity (i.e. great depth and high velocities) and damaging capacity of glacial lake outburst floods (GLOFs). GLOFs may increase in frequency as glaciers retreat and new lakes develop and there is an urgent need to better understand GLOF dynamics and the measures required to reduce their negative outcomes. In Patagonia at least 16 moraine-dammed lakes have failed in historic time, however, data about GLOF dynamics and impacts in this region are limited. We reconstruct a GLOF that affected a small village in Chilean Patagonia in March 1977, by semi structured interviews, interpretation of satellite images and 2D hydraulic modelling. This provides insight into the GLOF dynamics and the planning issues that led to socioeconomic consequences, which included village relocation. Modelling shows that the water released by the GLOF was in the order of 12-13 × 10(6)m(3) and the flood lasted for about 10h, reaching a maximum depth of ~1.5m in Bahía Murta Viejo, ~ 26 km from the failed lake. The lake had characteristics in common with failed lakes worldwide (e.g. the lake was in contact with a retreating glacier and was dammed by a narrow-steep moraine). The absence of land-use planning and the unawareness of the GLOF hazard contributed to the village flooding. The Río Engaño GLOF illustrates how small-scale and short-distance migration is a reasonable coping strategy in response to a natural hazard that may increase in frequency as atmospheric temperature rises and glaciers retreat. Copyright © 2015 Elsevier B.V. All rights reserved.

Distribución de macroinvertebrados (Plecoptera y Aeglidae en ecosistemas fluviales de la Patagonia chilena: ¿Muestran señales biológicas de la evolución geomorfológica postglacial? Distribution of macroinvertebrates (Plecoptera and Aeglidae in fluvial ecosystems of the Chilean Patagonia: Do they show biological signals of the postglacial geomorphological evolution?

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CLAUDIO VALDOVINOS

2010-06-01

Full Text Available La Patagonia chilena incluye uno de los sistemas hídricos más complejos de Sudamérica y uno de los menos intervenidos del mundo, los cuales fueron intensamente modelados por la actividad glacial del Cuaternario. El objetivo de este estudio fue determinar si en esta área existen zonas de endemismo de macroinvertebrados bentónicos fluviales y analizar los patrones de diversidad de organismos de alta (Plecoptera y baja vagilidad (Aeglidae. Entre el 2006 y 2009 se muestrearon 183 sitios entre 42°50' y 54°43' S, focalizándose en las principales cuencas. Los muéstreos se realizaron con una red "kicknet", cubriendo una superficie de fondo de 8 m². En toda el área se registraron 30 especies de Plecoptera y dos de Aeglidae. Se identificó una zona de endemismo en la cuenca del río Aysén, sustentada por el plecóptero Ceratoperla fazi y el cangrejo Aegla neuquensis. Esta última especie correspondería a una población relictual procedente de los ríos de la estepa Argentina, que habría quedado atrapada en la Patagonia chilena, luego que se invirtiera el flujo del cauce del río que originalmente fluía hacia el Atlántico. Un marcado cambio latitudinal en la diversidad de especies fue evidente a lo largo del área de estudio (R² = 0.72, P The Chilean Patagonia includes one of the most complex hydrological systems of South America and one of the least modified systems of the world. These systems were intensely modified by the glacial activity of the Quaternary. The objectives of this study were to determine whether or not in this area exists zones of endemic benthic fluvial macroinvertebrates, and to analyze the patterns of diversity of species composed by organisms of high (Plecoptera and low (Aeglidae vagility. A collection of 183 selected sites, located between the latitude 42° 50' and 54°43' S, were sampled during 2006 and 2009. The sampling was focused on the main river basins and a "kicknet" was used to cover a surface of 8 m² at

Propiedades microbiológicas en un suelo de la patagonia argentina bajo la influencia de diferentes especies forestales Microbiological properties of a soil of the argentine patagonia under the influence of different tree species

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Diana Noemí Effron

2011-12-01

Full Text Available En los sistemas forestales, la hojarasca es generalmente la principal fuente de nutrientes para la vegetación y microorganismos, pudiendo variar éstos en relación a la biomasa y calidad de los materiales aportados por diferentes especies. Las raíces de los árboles ejercen influencia en el desarrollo y actividad de la microflora. El objetivo de este trabajo fue evaluar la influencia sobre el suelo de dos especies arbóreas implantadas, con distinta composición del residuo vegetal aportado al suelo. El suelo está clasificado como un Andisol y está ubicado en la Estación Forestal Trevelín, Chubut, Argentina, Lat. 43º Sur, Long 71º31´ Oeste. Se extrajeron muestras superficiales de suelo de dos parcelas de bosque con una especie dominante cada una: Pino radiata (Pinus radiata D. Don. y Roble europeo (Quercus robur. Se determinó carbono orgánico, respiración microbiana, actividad deshidrogenasa, diversidad funcional de comunidades microbianas asociadas y se calculó el índice de diversidad de Shanon Weaver (H. Se cuantificaron bacterias totales, bacterias amilolíticas, actinomicetes y hongos. Los valores de respiración microbiana y carbono orgánico resultaron significativamente superiores en el suelo debajo de Roble. No se encontraron diferencias significativas entre valores de deshidrogenasa. Los recuentos de flora bacteriana total y de bacterias amilolíticas dieron significativamente superiores en el suelo asociado a Roble, mientras que los actinomicetes y hongos no mostraron diferencias significativas entre especies. El análisis de componentes principales mostró variaciones significativas en la fisiología de las comunidades microbianas asociadas a estas dos especies. El índice de diversidad H de la microflora fue significativamente mayor para Pino. Los residuos de Roble por ser una especie latifoliada y por lo tanto poseer menor contenido de sustancias recalcitrantes que una conífera, asociado al mayor desarrollo de

Primer registro de Naupactus ruizi (Coleoptera: Curculionoidea asociado con Pinus ponderosa (Gymnospermae: Pinaceae en Patagonia

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Cecilia A. GOMEZ

2006-01-01

Full Text Available Naupactus ruizi (Brèthes es un gorgojo de rostro corto, distribuido en la Argentina y Chile, que habita en ambientes áridos asociado con vegetación xerofítica y alcanza el rango más austral entre los miembros de la tribu Naupactini. Un relevamiento de insectos y de patógenos como plagas potenciales, realizado durante el 2005 en plantaciones de Pinus spp. en la Patagonia andina argentina, resultó en el hallazgo de adultos de N. ruizi que se alimentaban de acículas de Pinus ponderosa Dougl. ex Laws. Este hallazgo es sorprendente dado que las especies de Naupactini, consumen casi exclusivamente angiospermas. Interpretamos que el cambio de huésped, habría ocurrido como consecuencia de una colonización reciente favorecida por la amplia distribución geográfica del gorgojo y su capacidad para sobrevivir en hábitats marginales, donde probablemente las plantas nativas son escasas y el nuevo huésped presenta una gran abundancia local.

Deglacial palaeoclimate at Puerto del Hambre, subantarctic Patagonia, Chile

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Heusser, Calvin J.; Heusser, Linda E.; Lowell, Thomas V.; Moreira M., Andrés; Moreira M., Simón

2000-02-01

The primary objective of this study is to further substantiate multistep climatic forcing of late-glacial vegetation in southern South America. A secondary objective is to establish the age of deglaciation in Estrecho de Magallanes-Bahía Inútil. Pollen assemblages at 2-cm intervals in a core of the mire at Puerto del Hambre (53°3621S, 70°5553W) provide the basis for reconstructing the vegetation and a detailed account of palaeoclimate in subantarctic Patagonia. Chronology over the 262-cm length of core is regulated by 20 AMS radiocarbon dates between 14 455 and 10 089 14C yr BP. Of 13 pollen assemblage zones, the earliest representing the Oldest Dryas chronozone (14 455-13 000 14C yr BP) records impoverished steppe with decreasing frequencies and loss of southern beech (Nothofagus). Successive 100-yr-long episodes of grass/herbs and of heath (Empetrum/Ericaceae) before 14 000 14C yr BP infer deglacial successional communities under a climate of increased continentality prior to the establishment of grass-dominated steppe. The Bølling-Allerød (13 000-11 000 14C yr BP) is characterised by mesic grassland under moderating climate that with abrupt change to heath dominance after 12 000 14C yr BP was warmer and not as humid. At the time of the Younger Dryas (11 000-10 000 14C yr BP), grass steppe expanded with a return of colder, more humid climate. Later, with gradual warming, communities were invaded by southern beech. The Puerto del Hambre record parallels multistep, deglacial palaeoclimatic sequences reported elsewhere in the Southern Andes and at Taylor Dome in Antarctica. Deglaciation of Estrecho de Magallanes-Bahía Inútil is dated close to 14 455 14C yr BP, invalidating earlier dates of between 15 800 and 16 590 14C yr BP.

Volcanic nutrient inputs and trophic state of Lake Caviahue, Patagonia, Argentina

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Pedrozo, Fernando L.; Temporetti, Pedro F.; Beamud, Guadalupe; Diaz, Mónica M.

2008-12-01

The strategies for eutrophication control, remediation, and policy management are often defined for neutral to alkaline freshwater systems, as they are most suitable for human use. The influence of nutrients on eutrophication in a naturally-acidic lake is poorly known. The main purpose of the present work is to evaluate the significance of volcanic nutrients in the control of the trophic state of the acidic Lake Caviahue, located at North Patagonia, Argentina. Acidic water systems were most studied on artificial acidified lakes, such as mining lakes in Germany or pit lakes in the United States. Lake Caviahue received a very high P load (42-192 ton P/yr) and low N load (14 ton N/yr), mainly as ammonium with quite low N:P ratios (Copahue volcano represents the main natural contribution of nutrients and acidity to the Lake Caviahue. The lake is oligotrophic in terms of CHLa. Neither the transparency nor the nutrient, dissolved or particulate, contents are to date representative of the trophic state of the lake. High P loads do not imply the eutrophication of the lake. We suggest that nitrogen and not phosphorus represents the key control nutrient in volcanically acidified lakes as TON was better related to CHLa observed (0.13-0.36 mg/m 3) in the lake. The pH increased around one unit (pH 2.0-3.0) during the last five years suggesting that the lake has not yet returned to a stable state.

Organic carbon in glacial fjords of Chilean Patagonia

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Pantoja, Silvio; Gutiérrez, Marcelo; Tapia, Fabián; Abarzúa, Leslie; Daneri, Giovanni; Reid, Brian; Díez, Beatriz

2016-04-01

The Southern Ice Field in Chilean Patagonia is the largest (13,000 km2) temperate ice mass in the Southern hemisphere, yearly transporting ca. 40 km3 of freshwater to fjords. This volume of fresh and cold water likely affects adjacent marine ecosystems by changing circulation, productivity, food web dynamics, and the abundance and distribution of planktonic and benthic organisms. We hypothesize that freshwater-driven availability of inorganic nutrient and transport of organic and inorganic suspended matter, as well as microbes, become a controlling factor for productivity in the fjord associated with the Baker river and Jorge Montt glacier. Both appear to be sources of silicic acid, but not of nitrate and particulate organic carbon, especially during summer, when surface PAR and glacier thawing are maximal. In contrast to Baker River, the Jorge Montt glacier is also a source of dissolved organic carbon towards a proglacial fjord and the Baker Channel, indicating that a thorough chemical description of sources (tidewater glacier and glacial river) is needed. Nitrate in fiord waters reaches ca. 15 μM at 25 m depth with no evidence of mixing up during summer. Stable isotope composition of particulate organic nitrogen reaches values as low as 3 per mil in low-salinity waters near both glacier and river. Nitrogen fixation could be depleting δ15N in organic matter, as suggested by the detection at surface waters of nif H genes belonging to diazotrophs near the Montt glacier. As diazotrophs have also been detected in other cold marine waters (e.g. Baltic Sea, Arctic Ocean) as well as glaciers and polar terrestrial waters, there is certainly a potential for both marine and freshwater microbes to contribute and have a significant impact on the Patagonian N and C budgets. Assessing the impact of freshwater on C and N fluxes and the microbial community structure in Patagonian waters will allow understanding future scenarios of rapid glacier melting. This research was funded

LOS MISTERIOS Y LAS ANDANZAS DE UN TRABAJO DE CAMPO EN LA PATAGONIA: EL LUGAR DE LOS 100 AÑOS DE COMODORO RIVADAVIA

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Elena M. Pacheco

2003-12-01

Full Text Available Desde hace algunos años la línea de investigación que estoy desarrollando está centrada en los rituales urbanos, más específicamente analizo fiestas aniversario y otras festividades que desde el año 1990 se celebran de manera interrumpida en distintas localidades patagónicas que han sido organizadas a partir de la acción modeladora de la empresa estatal Yacimientos Petrolíferos Fiscales (Y.P.F.. El abordaje considera cómo a través de los “nuevos festejos” las localidades impactadas por el proceso de reestructuración del estado y la consecuente privatización de la petrolera estatal (Y.P.F. buscan llenar los vacíos de simbolismo que otrora ocupaba el petróleo. El 23 de febrero del año 2001 “mi ciudad” (Comodoro Rivadavia, Chubut festejó 100 años de su fundación y fui hacer trabajo de campo a efectos de completar un informe de investigación. Preparé el grabador, los casettes, la libreta de campo y todo lo necesario para “actuar” como etnógrafa.

An Assessment of Oil Pollution in the Coastal Zone of Patagonia, Argentina

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Commendatore, Marta Graciela; Esteves, José Luis

2007-11-01

The Patagonian coast is considered a relatively pristine environment. However, studies conducted along coastal Patagonia have showed hydrocarbon pollution mostly concentrated at ports that have fishing, oil loading, general merchant, and/or tourist activities. A high value of total aliphatic hydrocarbons (TAH) was found at the Rawson fishing port (741 μg/g dw). In other ports with and without petroleum-related activities, hydrocarbon values were approximately 100 μg/g dw. The highest values for TAH and total aromatic hydrocarbons (TArH) were found in Faro Aristizábal, north of San Jorge gulf (1304 and 737 μg/g dw, respectively). This is very likely the result of petroleum-related activities at the Comodoro Rivadavia, Caleta Cordova, and Caleta Olivia ports located within this gulf. In other coastal areas away from potential anthropogenic sources, hydrocarbon values were less than 2 and 3 μg/g dw for TAH and TArH, respectively. This review of published and unpublished information suggests that ports are important oil pollution sources in the Patagonian coast. More detailed studies are needed to evaluate the area affected by port activities, to understand the mechanisms of hydrocarbon distribution in surrounding environments, and to assess bioaccumulation in marine organisms. Despite that some regulations exist to control oil pollution derived from port and docked vessel activities, new and stricter management guidelines should be implemented.

Saccharomyces uvarum is responsible for the traditional fermentation of apple chicha in Patagonia.

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Rodríguez, Maria E; Pérez-Través, Laura; Sangorrín, Marcela P; Barrio, Eladio; Querol, Amparo; Lopes, Christian A

2017-01-01

Apple chicha is a fresh low alcoholic beverage elaborated by aboriginal communities of Andean Patagonia (Argentina and Chile). In the present work, we identified the yeast microbiota associated with this fermentation, and characterized genetically those belonging to the genus Saccharomyces. Both Saccharomyces cerevisiae and S. uvarum were found in the analyzed fermentations. Phylogenetic and population structure analyses based on genes sequence analysis were carried out for both S. cerevisiae and S. uvarum strains obtained in this study and a set of additional strains from diverse origins. The results demonstrate that S. cerevisiae strains from apple chicha belong to the big group of wine/European strains of this species, while S. uvarum strains were included in the Holartic population of this species. Additionally, some S. uvarum strains from chichas evidenced as an admixture of both pure Holartic and pure South American populations. Our results suggest that Holartic strains could have been introduced in South America together with the domestication of apple trees by Mapuche communities. This Holartic population suffered admixis with the naturally present South American population of this species, originating strains bearing genetic features from the two populations, detectable in both chichas and natural habitats. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

LA GEOPEDOLOGIA COMO BASE PARA ZONIFICAR LA APTITUD FORESTAL EN UNA CUENCA DEL NOROESTE DE LA PATAGONIA ARGENTINA

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Maria Cristina Frugoni

2016-12-01

Full Text Available Geopedology at a semi-detailed scale (1:50.000 was carried out in Buta Mallín catchment which includes an area of 21.065ha, in the northwest of Neuquén province, Argentine Patagonia. Geopedology provides a spatial dimension of soil-landscape relations, which are displayed in a map and its legend, showing the geoforms (contours and their soils (content, based on the premise that soil is landscape as well as profile. According to this approach three landscapes were recognized: glacial modeled mountains, plateau and valley. The relief consists mainly of steep to very steep slopes, and valley bottoms with poorly drained soils. Lithology (parent material corresponds to holocene volcanic ash in the western sector of the study area, while the eastern sector is dominated by tuff. Twenty terrain forms and their soils were identified. With this basic information, attribute tables were constructed considering landscape and soil properties. Regarding soils, physical fertility properties were considered, since these are the most correlated ones with Pinus ponderosa (pino ponderosa growth, the main species used in afforestation in Patagonia. Those tables were included and analized with a GIS (Geographic Information System to obtain a forest suitability map. The study area shows four forest suitability classes. Suitable: 37ha; moderately suitable: 4.512ha; marginally suitable: 6.072ha; not suitable: 10.444ha. The main limitations of the area are the very steep slopes, height and the areas dominated by rock outcrops and detrital covers. Nothofagus antarctica (ñire shrubs cover part of the suitable areas; because of conservation criteria of these natural communities, these lands were considered not suitable. On the other side, there are more than 4.000 ha of moderately suitable lands, which can be considered for a more detailed study. Transhumant cattle raising is the main land use system in this catchment, which is an ancient culture of the Northern Neuquian

P-wave velocity structure beneath the northern Antarctic Peninsula: evidence of a steeply subducting slab and a deep-rooted low-velocity anomaly beneath the central Bransfield Basin

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Park, Yongcheol; Kim, Kwang-Hee; Lee, Joohan; Yoo, Hyun Jae; Plasencia L., Milton P.

2012-12-01

Upper-mantle structure between 100 and 300 km depth below the northern Antarctic Peninsula is imaged by modelling P-wave traveltime residuals from teleseismic events recorded on the King Sejong Station (KSJ), the Argentinean/Italian stations (JUBA and ESPZ), an IRIS/GSN Station (PMSA) and the Seismic Experiment in Patagonia and Antarctica (SEPA) broad-band stations. For measuring traveltime residuals, we applied a multichannel cross-correlation method and inverted for upper-mantle structure using VanDecar's method. The new 3-D velocity model reveals a subducted slab with a ˜70° dip angle at 100-300 km depth and a strong low-velocity anomaly confined below the SE flank of the central Bransfield Basin. The low velocity is attributed to a thermal anomaly in the mantle that could be as large as 350-560 K and which is associated with high heat flow and volcanism in the central Bransfield Basin. The low-velocity zone imaged below the SE flank of the central Bransfield Basin does not extend under the northern Bransfield Basin, suggesting that the rifting process in that area likely involves different geodynamic processes.

Intestinal helminth fauna of the South American sea lion Otaria flavescens and fur seal Arctocephalus australis from northern Patagonia, Argentina.

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Hernández-Orts, J S; Montero, F E; Juan-García, A; García, N A; Crespo, E A; Raga, J A; Aznar, F J

2013-09-01

We report on the intestinal helminth fauna of 56 South American sea lions, Otaria flavescens, and 5 South American fur seals, Arctocephalus australis, from northern Patagonia, Argentina. A total of 97,325 helminth specimens were collected from sea lions. Gravid individuals were represented by 6 species of parasites: 1 digenean (Ascocotyle (Ascocotyle) patagoniensis), 1 cestode (Diphyllobothrium spp.), 3 nematodes (Uncinaria hamiltoni, Contracaecum ogmorhini s.s., Pseudoterranova cattani) and 1 acanthocephalan (Corynosoma australe). In addition, third-stage larvae of 2 nematodes (Contracaecum sp. and Anisakis sp. type I) and 3 juvenile acanthocephalans (Andracantha sp., Profilicollis chasmagnathi and Corynosoma cetaceum) were also collected. Andracantha sp., C. ogmorhini s.s. and P. chasmagnathi represent new host records. A total of 1516 helminth specimens were collected from fur seals. Gravid individuals were represented by three species of parasites, namely, Diphyllobothrium spp., C. ogmorhini s.s. and C. australe. In addition, larvae of Contracaecum sp. and P. cattani, juveniles of C. cetaceum and immature cestodes (Tetrabothriidae gen. sp.) were also collected. Corynosoma australe was the most prevalent and abundant parasite in both hosts, accounting for >90% of all specimens. Sea lions and furs seals from northern Patagonia harbour the intestinal helminth communities that could be predicted for otariids, i.e. the combination of species of the genera Corynosoma, Diphyllobothrium, Pseudoterranova, Contracaecum and, in pups, Uncinaria. Additionally, both species of otariid are apparently unsuitable hosts (i.e. non-hosts) for as many as five parasite taxa. The inclusion or exclusion of these species affects estimation of species richness at both component community (11 versus 6 species in sea lions; 7 versus 3 species in fur seals) and infracommunity (mean: 3.1 versus 2.6 in sea lions; 2.2 versus 1.7 species) levels. Information about the reproductive status of

ESTIMACIÓN DE EROSIÓN HIDRICA DE SUELOS PARA PLAN DE MANEJO DEL CAMPO FORESTAL AGUAS FRÍAS, PATAGONIA ARGENTINA

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Ana C. Dufilho

2011-12-01

Full Text Available In Argentine Patagonia there exist large extensions of lands degraded by overgrazing, this favours soil water erosion. Two million hectares are eligible for forestation (Gallo et al. 2005, with some environmental limitations that require previous studies to prepare development and sustainability proposals. The study area is located in the right margin of the Litrán River, 25 kms of its estuary in Aluminé Lake (Province of Neuquén. In this area, some Mapuche (araucanian communities carry out stock breeding (mainly goats using a migrating system. This region presents very severe Aeolian and hydrological erosion. The objective of the afforestation management plan of this land, is the design of control measures, to stop erosion, like perimeter close, afforestation and structural measures for controlling erosional gully. It is then necessary, to characterize the actual and potential erosion, that would allow to carry out with measures monitoring to implement controls and mitigation. Paper presents, pedology map by interpreting and georreferencing satellite images by a Geographical Information System. (GIS. The mapping methodology was based in Hierarchical Classification of Landforms, which is the structure of the geopedology focus for mapping soil (Zinck, 1989. The classification of actual erosion was obtained from the method of the Bureau of Land Management (USDI by visual inspection of seven aspects of erosion in surface. The estimation of the potential erosion of the floors of the forest field was carried out utilizing the Universal Soil Lost Equation (USLE and ArcGis 9,2 (ESRI, 2006 to carry out the spatial analysis, obtaining a map of annual soil loss ( tn/has/year with a spatial resolution of 30 m. The application of spatial analysis tools in the study of soil water erosion in Patagonia, Argentina contributes to the objective of defining define a program of development and adequate management, as a function of the state and degree of

Diversity, distribution and floral specificity of tangle-veined flies (Diptera: Nemestrinidae in north west Patagonia, Argentina Diversidad, distribución y especificidad floral de nemestrínidos (Diptera en el noroeste de la Patagonia, Argentina

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MARIANO DEVOTO

2006-03-01

Full Text Available Tangle-veined flies (Nemestrinidae constitute a primitive and rather widespread family among Diptera. The genus Trichophthalma occurs in Australia and South America and is the only one in the family with a typically Gondwanian, disjoint distribution. The ecology and distribution of most southern South American species of this genus remains virtually unknown. We studied the diversity, distribution and flower specificity of flower-visiting species of the genus Trichophthalma in the temperate forests of southern South America in ten sites along an east-west rainfall gradient (37-40°S on the eastern slope of the Andes. We recorded nine species of Trichophthalma, which showed an overlapped distribution along the gradient and different degrees of floral specificity. Three species are reported for Argentina for the first time and three are first recorded as flower visitors to the local flora. Our results show that while in southern Africa tangle-veined flies are engaged in highly specialized pollination interactions with long-tubed species, the Trichophthalma spp. of Patagonia share their flowers with a diverse and rather unspecialized visitor fauna among which several species of flies, bees and birds are presentLos nemestrínidos constituyen una familia de Dípteros primitiva y de amplia distribución. El género Trichophthalma se encuentra en Australia y Sudamérica y es el único en la familia con una distribución disjunta típicamente gondwánica. La ecología y distribución de la mayoría de las especies sudamericanas permanecen virtualmente desconocidas. Estudiamos la diversidad, distribución y especificidad floral de las especies del género Trichophthalma de los bosques templados del sur de Sudamérica en diez sitios ubicados a lo largo de un gradiente de precipitación este-oeste (37-40°S sobre la vertiente occidental de los Andes. Registramos nueve especies de Trichophthalma, las cuales mostraron una distribución superpuesta a lo largo

Morfometría externa y reparto de recursos en zorros simpátricos (Pseudalopex culpaeus y P. griseus) en el sureste de la Patagonia Argentina

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Zapata, Sonia C.; Procopio, Diego E.; Martínez-Peck, Rolando; Zanón, Juan I.; Travaini, Alejandro

2008-01-01

Estudios previos han demostrado que el tamaño corporal de zorros grises o chillas (Pseudalopex griseus) y colorados o culpeos (P. culpaeus) es similar en alopatría, y que en simpatría se produce una divergencia en el tamaño de ambos zorros. El aumento en la diferencia del tamaño corporal entre las dos especies hacia la porción más austral de su distribución (Patagonia Argentina y sur de Chile) permitiría una especialización hacia diferentes recursos favoreciendo su coexistencia. Sin embargo, ...

A new sauropodomorph dinosaur from the Early Jurassic of Patagonia and the origin and evolution of the sauropod-type sacrum.

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Diego Pol

2011-01-01

Full Text Available The origin of sauropod dinosaurs is one of the major landmarks of dinosaur evolution but is still poorly understood. This drastic transformation involved major skeletal modifications, including a shift from the small and gracile condition of primitive sauropodomorphs to the gigantic and quadrupedal condition of sauropods. Recent findings in the Late Triassic-Early Jurassic of Gondwana provide critical evidence to understand the origin and early evolution of sauropods.A new sauropodomorph dinosaur, Leonerasaurus taquetrensis gen. et sp. nov., is described from the Las Leoneras Formation of Central Patagonia (Argentina. The new taxon is diagnosed by the presence of anterior unserrated teeth with a low spoon-shaped crown, amphicoelous and acamerate vertebral centra, four sacral vertebrae, and humeral deltopectoral crest low and medially deflected along its distal half. The phylogenetic analysis depicts Leonerasaurus as one of the closest outgroups of Sauropoda, being the sister taxon of a clade of large bodied taxa composed of Melanorosaurus and Sauropoda.The dental and postcranial anatomy of Leonerasaurus supports its close affinities with basal sauropods. Despite the small size and plesiomorphic skeletal anatomy of Leonerasaurus, the four vertebrae that compose its sacrum resemble that of the large-bodied primitive sauropods. This shows that the appearance of the sauropod-type of sacrum predated the marked increase in body size that characterizes the origins of sauropods, rejecting a causal explanation and evolutionary linkage between this sacral configuration and body size. Alternative phylogenetic placements of Leonerasaurus as a basal anchisaurian imply a convergent acquisition of the sauropod-type sacrum in the new small-bodied taxon, also rejecting an evolutionary dependence of sacral configuration and body size in sauropodomorphs. This and other recent discoveries are showing that the characteristic sauropod body plan evolved gradually

Utility of high-altitude infrared spectral data in mineral exploration: Application to Northern Patagonia Mountains, Arizona

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Berger, B.R.; King, T.V.V.; Morath, L.C.; Phillips, J.D.

2003-01-01

Synoptic views of hydrothermal alteration assemblages are of considerable utility in regional-scale minerals exploration. Recent advances in data acquisition and analysis technologies have greatly enhanced the usefulness of remotely sensed imaging spectroscopy for reliable alteration mineral assemblages mapping. Using NASA's Airborne Visible Infrared Imaging Spectrometer (AVIRIS) sensor, this study mapped large areas of advanced argillic and phyllic-argillic alteration assemblages in the southeastern Santa Rita and northern Patagonia mountains, Arizona. Two concealed porphyry copper deposits have been identified during past exploration, the Red Mountain and Sunnyside deposits, and related published hydrothermal alteration zoning studies allow the comparison of the results obtained from AVIRIS data to the more traditional field mapping approaches. The AVIRIS mapping compares favorably with field-based studies. An analysis of iron-bearing oxide minerals above a concealed supergene chalcocite deposit at Red Mountain also indicates that remotely sensed data can be of value in the interpretation of leached caps above porphyry copper deposits. In conjunction with other types of geophysical data, AVIRIS mineral maps can be used to discriminate different exploration targets within a region.

Dietary analysis of Homonota darwini (Squamata: Gekkoni-dae in Northern Patagonia

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Marcelo E. KUN, Carla PIANTONI, John D. KRENZ, Nora R. IBARGÜENGOYTÍA

2010-08-01

Full Text Available Our study investigated the diet of the southernmost gecko in the world, Homonota darwini. Fifty-three specimens were captured during spring and summer in four locations in Patagonia, Argentina. The stomach contents of the specimens were identified, and we found that prey consisted of six main groups: Coleoptera, Hymenoptera, Homoptera and Araneae, and the adults and larvae of moth Lepidoptera. Lepidoptera was the major dietary component. The presence of ants and moths as common prey suggests an ambush feeding strategy. In spring, females consumed more ants than males although no other dietary differences between males and females were evident. We found nine geckos with empty stomachs and six parasitized by nematodes. Presence of empty stomachs corroborates previous observations of other nocturnal geckos and non-gecko lizards. Reduced foraging success of nocturnal lizards could be due to difficulty in prey detection due to dim light, reduced or erratic activity of insect prey at night, or shorter activity times of geckos relative to diurnal success. Sex and season were not associated with the incidence of empty stomachs. Principal component analysis showed that four food alternatives correlated with season. The constraint of nocturnality, coupled with low night-time temperatures restricting feeding to only a few hours after sunset, appear to have caused a generality of diet which may limit energy acquisition. We conclude that H. darwini is an arthropod generalist and likely an ambush forager, as are many other nocturnal gekkonids [Current Zoology 56 (4: 406–410, 2010].

Desarrollo morfológico y conductual de pollos del aguilucho chico Buteo albigula (Aves: Accipitridae en el noroeste de la Patagonia argentina Morphologic and behavioral development of white-throated hawk Buteo albigula (Aves: Accipitridae nestlings in northwestern Argentine Patagonia

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VALERIA OJEDA

2003-09-01

Full Text Available El desarrollo morfológico y conductual del aguilucho chico (Buteo albigula en el nido fue estudiado en cercanías de San Carlos de Bariloche, al noroeste de la Patagonia argentina. El estudio se basó en el seguimiento de dos pollos producidos en diferentes nidos en la temporada reproductiva 2001-2002, y se lo complementó con datos tomados ad libitum en otros nidos, esa misma y anteriores temporadas. Los pollos permanecieron en el nido por aproximadamente seis semanas. Durante su desarrollo morfológico se evidenciaron diversos cambios; notablemente, la aparición secuencial de dos plumones natales, que solo fue observada entre especies de Buteo neotropicales, para B. brachyurus. La conducta de los pollos se encuadró en los patrones comunes para otras especies de Buteo de tamaño corporal similar. Además, se caracterizó, por primera vez para la Argentina, un juvenil (muerto accidentalmente, y se tomaron medidas y peso (por primera vez para B. albigula de dos adultos anillados cerca de sus nidos. El juvenil fue relativamente similar al descrito en Chile. Los adultos, que serían los primeros aguiluchos chicos en ser anillados, se suman a los escasos ejemplares medidos en el área reproductiva conocida de la especie.The morphological and behavioral development of white-throated hawk (Buteo albigula nestlings was studied near San Carlos de Bariloche, in northwestern Argentine Patagonia. The study was mainly based on the monitoring of two nestlings produced at different nests during 2001-2002 breeding season, and was reinforced with data obtained at libitum in other nests the same and previous breeding seasons. The nestling period extended for approximately 6 weeks. Morphological development was characterized by several changing features, but the most surprising was the development of first and second natal down, which was only known, among Neotropical Buteo species, for B. brachyurus. Nestling behavioral development matched the general

Nuisance ecology: do scavenging condors exact foraging costs on pumas in Patagonia?

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Elbroch, L Mark; Wittmer, Heiko U

2013-01-01

Predation risk describes the energetic cost an animal suffers when making a trade off between maximizing energy intake and minimizing threats to its survival. We tested whether Andean condors (Vultur gryphus) influenced the foraging behaviors of a top predator in Patagonia, the puma (Puma concolor), in ways comparable to direct risks of predation for prey to address three questions: 1) Do condors exact a foraging cost on pumas?; 2) If so, do pumas exhibit behaviors indicative of these risks?; and 3) Do pumas display predictable behaviors associated with prey species foraging in risky environments? Using GPS location data, we located 433 kill sites of 9 pumas and quantified their kill rates. Based upon time pumas spent at a carcass, we quantified handling time. Pumas abandoned >10% of edible meat at 133 of 266 large carcasses after a single night, and did so most often in open grasslands where their carcasses were easily detected by condors. Our data suggested that condors exacted foraging costs on pumas by significantly decreasing puma handling times at carcasses, and that pumas increased their kill rates by 50% relative to those reported for North America to compensate for these losses. Finally, we determined that the relative risks of detection and associated harassment by condors, rather than prey densities, explained puma "giving up times" (GUTs) across structurally variable risk classes in the study area, and that, like many prey species, pumas disproportionately hunted in high-risk, high-resource reward areas.

A new species of Ascocotyle (Trematoda: Heterophyidae) from the South American sea lion, Otaria flavescens, off Patagonia, Argentina.

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Hernández-Orts, Jesús Servando; Montero, Francisco Esteban; Crespo, Enrique Alberto; García, Néstor Aníbal; Raga, Juan Antonio; Aznar, Francisco Javier

2012-08-01

We describe a new heterophyid species, Ascocotyle (Ascocotyle) patagoniensis n. sp., based on specimens collected from the intestines of the South American sea lion Otaria flavescens from Patagonia (Argentina). Ascocotyle (A.) patagoniensis n. sp. is distinguished from the other species of the subgenus by the number of circumoral spines, which are arranged in 2 rows of 18 to 23. The new species also differs from the other species in having a gonotyl without papillae. The specimens exhibited the widest seminal receptacle described for a species of this subgenus. Species of the subgenus Ascocotyle usually infect fish-eating birds or mammals in freshwater or brackish habitats. Ascocotyle (A.) patagoniensis n. sp. is the first species of the subgenus described from a marine mammal. However, no metacercariae of Ascocotyle spp. were found in 542 marine teleosts from 20 species collected in the same locality. The life cycle of the marine species from the Ascocotyle -complex infecting pinnipeds remains elusive.

Firewood Resource Management in Different Landscapes in NW Patagonia

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Daniela V. Morales

2017-09-01

Full Text Available Ecosystems, their components, processes and functions are all subject to management by human populations, with the purpose of adapting the environments to make them more habitable and ensuring the availability and continuity of subsistence resources. Although a lot of work has been carried out on resources of alimentary or medicinal interest, little has been done on associating processes of domestication with firewood extraction, a practice considered to be destructive of the environment. In the arid steppe of NW Patagonia, inhabited and managed for different purposes for a long time by Mapuche-Tehuelche communities, the gathering of combustible plant species has up to the present time played a crucial role in cooking and heating, and work is required to achieve sustainability of this resource. In this study we evaluate whether environments with less landscape domestication are more intensively used for firewood gathering. Using an ethnobiological approach, information was obtained through participant observation, interviews and free listing. The data were examined using both qualitative and quantitative approaches. Twenty-eight firewood species are gathered, both native (75% and exotic (25%. The supply of firewood mainly depends on gathering from the domesticated (10 species, semi-domesticated (17 species and low human intervention landscapes (17 species. In contrast to our hypothesis, average use intensity is similar in all these landscapes despite their different levels of domestication. That is, the different areas are taken advantage of in a complementary manner in order to satisfy the domestic demand for firewood. Neither do biogeographic origin or utilitarian versatility of collected plants vary significantly between the different landscape levels of domestication. Our results show that human landscape domestication for the provision of firewood seems to be a socio-cultural resilient practice, and shed new light on the role of culture in

Estudio transversal de las parasitosis intestinales en poblaciones infantiles de Argentina

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Graciela Teresa Navone

2017-06-01

Full Text Available RESUMEN Objetivo Determinar la distribución de las enteroparasitosis en niños de nueve provincias representativas del mosaico de ambientes contrastantes de Argentina. Métodos Estudio descriptivo, observacional y transversal en niños preescolares (de 5 años o menos y escolares (de 6 a 14 años de las provincias de Buenos Aires (muestra tomada entre 2005 y 2013, Chubut (2010-2013, Corrientes (2012, Entre Ríos (2010-2012, Formosa (2014, La Pampa (2006, Mendoza (2008-2011, Misiones (2005-2008 y 2013 y Salta (2012-2013. Se procesaron muestras seriadas, fecales y de escobillado anal, mediante técnicas de concentración. Los resultados se analizaron por sexo, intervalo de edad y provincia. Se calcularon la frecuencia de parasitosis (monoparasitosis y parasitosis múltiple, la riqueza de especies y el coeficiente de similitud de Sørensen. Resultados Misiones presentó la mayor frecuencia de niños parasitados y Chubut la menor (82,0% vs. 38,4%; p ˂ 0,01. El número de especies fue mayor en Misiones y Buenos Aires y menor en Chubut y La Pampa. Los varones estuvieron más parasitados que las mujeres solo en Buenos Aires. Las mayores frecuencias se encontraron en los preescolares de Buenos Aires y los escolares de Mendoza y Misiones (p < 0,05. La monoparasitosis fue más frecuente en Chubut (67,9% y las parasitosis múltiples en Formosa (69,2%. Las especies más frecuentes en la mayoría de las provincias fueron Blastocystis sp. y Enterobius vermicularis. De los geohelmintos, Misiones presentó la mayor frecuencia (23,3% y Mendoza la menor (0,6%; no se hallaron en Chubut, La Pampa y Salta. Buenos Aires, Formosa y Misiones presentaron una composición de especies similar, al igual que Chubut y La Pampa. Conclusiones Las frecuencias de parasitosis en Argentina responden al complejo mosaico de variabilidad climática y socioeconómica del país y revelan una tendencia descendente de norte a sur y de este a oeste.

Southern westerly winds: a pacemaker of Holocene glacial fluctuations in Patagonia?

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Sagredo, E. A.; Reynhout, S.; Kaplan, M. R.; Patricio, M. I.; Aravena, J. C.; Martini, M. A.; Schaefer, J. M.

2017-12-01

A well-resolved glacial chronology is crucial to compare sequences of glacial/climate events within and between regions, and thus, to unravel mechanisms underlying past climate changes. Important efforts have been made towards understanding the Holocene climate evolution of the Southern Andes; however, the timing, patterns and causes of glacial fluctuations during this period still remain elusive. Recent advances in terrestrial cosmogenic nuclide surface exposure dating, together with the establishment of a Patagonian 10Be production rate, have opened new possibilities for establishing high-resolution glacial chronologies at centennial/decadal scale. Here we present a 10Be surface exposure chronology of fluctuations of a small, climate-sensitive mountain glacier at Mt. Fitz Roy area (49.3°S), spanning from the last glacial termination to the present. Thirty new 10Be ages show glacial advances and moraine building events at 17.1±0.9 ka, 13.5±0.5 ka, 10.2±0.7 ka or 9.9±0.5 ka, 6.9±0.2 ka, 6.1±0.3 ka, 4.5±0.2 ka and 0.5±0.1 ka. Similar to the pattern observed in New Zealand, this sequence features progressively less extensive glacial advances during the late-glacial and early Holocene, followed by advances of roughly similar extent during the mid- to late-Holocene. We suggest that while the magnitude of Holocene glacial fluctuations in Patagonia is modulated by SH summer insolation ("modulator"), the specific timing of these glacial events is influenced by centennial-scale shifts of the Southern Westerly Winds ("pacemaker").

Autolysis at the disintegrin domain of patagonfibrase, a metalloproteinase from Philodryas patagoniensis (Patagonia Green Racer; Dipsadidae) venom.

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Peichoto, María E; Paes Leme, Adriana F; Pauletti, Bianca A; Batista, Isabel Correia; Mackessy, Stephen P; Acosta, Ofelia; Santoro, Marcelo L

2010-09-01

Patagonfibrase is a 57.5-kDa hemorrhagic metalloproteinase isolated from the venom of Philodryas patagoniensis (Patagonia Green Racer), a South American rear-fanged snake. Herein we demonstrate that patagonfibrase undergoes autolysis at its pH optimum (7.5) and at 37 degrees C, primarily producing a approximately 32.6 kDa fragment composed of disintegrin-like and cysteine-rich domains, as identified by mass spectrometry and N-terminal sequencing. The autolysis site for production of this fragment is similar to that observed for metalloproteinases from front-fanged Viperidae snake venoms. In the presence of Ca(2+), patagonfibrase was only partially autolysed, giving rise mainly to one fragment of approximately 52.2 kDa. In addition, calcium markedly enhanced the azocaseinolytic activity of patagonfibrase. Our findings contribute to the understanding of the structural and mechanistic bases of this family of metalloenzymes that are widely distributed among snake venoms, demonstrating that important post-translational modifications such as proteolysis can also contribute to the diversity and complexity of proteins found in rear-fanged snake venoms. Copyright © 2010 Elsevier B.V. All rights reserved.

[Cross-sectional study of intestinal parasitosis in child populations in Argentina].

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Navone, Graciela Teresa; Zonta, María Lorena; Cociancic, Paola; Garraza, Mariela; Gamboa, María Inés; Giambelluca, Luis Alberto; Dahinten, Silvia; Oyhenart, Evelia Edith

2017-06-08

Determine the distribution of intestinal parasitosis in children in nine provinces representative of Argentina's mosaic of contrasting environments. Descriptive, observational, cross-sectional study of preschool children (5 years old or under) and school-age children (6-14 years) in the provinces of Buenos Aires (sample taken between 2005 and 2013), Chubut (2010-2013), Corrientes (2012), Entre Ríos (2010-2012), Formosa (2014), La Pampa (2006), Mendoza (2008-2011), Misiones (2005-2008 and 2013), and Salta (2012-2013). Serial samples, fecal samples, and anal swabs were processed using concentration techniques. The results were analyzed by sex, age interval, and province. Frequency of parasitosis (monoparasitosis and multiple parasitoses), wealth of species, and Sørensen similarity coefficient were calculated. Misiones presented the highest frequency of parasitized children and Chubut the lowest (82.0% vs 38.4%; p parasitosis in Formosa (69.2%). The most frequent species in the majority of provinces were Blastocystis sp. and Enterobius vermicularis. Misiones presented the highest frequency of soil-transmitted helminthes (23.3%) and Mendoza the lowest (0.6%); none were found in Chubut, La Pampa, or Salta. Buenos Aires, Formosa, and Misiones presented a similar species composition, as did Chubut and La Pampa. The frequency of parasitosis in Argentina corresponds to the country's complex mosaic of climatic and socioeconomic variability and shows a declining trend from north to south and from east to west.

Late Cretaceous paleosols as paleoclimate proxies of high-latitude Southern Hemisphere: Mata Amarilla Formation, Patagonia, Argentina

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Varela, Augusto N.; Raigemborn, M. Sol; Richiano, Sebastián; White, Tim; Poiré, Daniel G.; Lizzoli, Sabrina

2018-01-01

Although there is general consensus that a global greenhouse climate characterized the mid-Cretaceous, details of the climate state of the mid-Cretaceous Southern Hemisphere are less clearly understood. In particular, continental paleoclimate reconstructions are scarce and exclusively derived from paleontological records. Using paleosol-derived climofunction studies of the mid- to Upper Cretaceous Mata Amarilla Formation, southern Patagonia, Argentina, we present a reconstruction of the mid-Cretaceous climate of southern South America. Our results indicate that at 60° south paleolatitude during the Cenomanian-Santonian stages, the climate was subtropical temperate-warm (12 °C ± 2.1 °C) and humid (1404 ± 108 mm/yr) with marked rainfall seasonality. These results are consistent with both previous estimations from the fossil floras of the Mata Amarilla Formation and other units of the Southern Hemisphere, and with the previous observations of the displacement of tropical and subtropical floras towards the poles in both hemispheres. The data presented here show a more marked seasonality and slightly lower mean annual precipitation and mean annual temperature values than those recorded at the same paleolatitudes in the Northern Hemisphere.

Reproductive biology of Sympterygia bonapartii (Chondrichthyes: Rajiformes: Arhynchobatidae in San Matías Gulf, Patagonia, Argentina

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María L. Estalles

2017-04-01

Full Text Available ABSTRACT This study estimates and analyses the reproductive parameters and cycle of Sympterygia bonapartii in San Matías Gulf, northern Patagonia, Argentina. A total of 827 males and 1,299 females were analysed. Males ranged from 185 to 687 mm of total length (TL and females from 180 to 742 mm TL. Sexual dimorphism was detected; females were larger, heavier, exhibited heavier livers, wider discs and matured at lager sizes than males. Immature females ranged from 180 to 625 mm TL, maturing females from 408 to 720 mm TL, mature ones from 514 to 742 mm TL and females with egg capsules from 580 to 730 mm TL. Immature males ranged from 185 to 545 mm TL, maturing ones from 410 to 620 mm TL and mature males from 505 to 687 mm TL. Size at which 50% of the skates reached maturity was estimated to be 545 mm TL for males and 594 mm TL for females. According to the reproductive indexes analysed, S. bonapartii exhibited a seasonal reproductive pattern. Mating may occur during winter-early spring and the egg-laying season, during spring and summer.

Late Pleistocene ecological, environmental and climatic reconstruction based on megafauna stable isotopes from northwestern Chilean Patagonia

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González-Guarda, Erwin; Domingo, Laura; Tornero, Carlos; Pino, Mario; Hernández Fernández, Manuel; Sevilla, Paloma; Villavicencio, Natalia; Agustí, Jordi

2017-08-01

Stable isotope analyses have been performed on the bioapatite (δ13C; δ18O) and collagen (δ13C; δ15N) of four late Pleistocene South American megafaunal taxa (Notiomastodon platensis, Equus andium, cf. Hemiauchenia paradoxa and Xenarthra indet.) to evaluate paleoclimatic and paleoenvironmental conditions as well as paleoecological features of this time period. The analyzed megafauna was found at several locations in the northwestern Chilean Patagonia (38°-42°S, 74°-71°W). The bioapatite δ13C values indicated the presence of C3 vegetation ranging from forestal to woodland areas. The collagen δ15N values pointed to temperate and humid ecosystems, and to the consumption of shrubs, trees, grasses and sedges. Mean annual temperatures estimated from bioapatite δ18OPO4 values show a similarity to modern temperatures and suggested that the megafauna under study may have lived during warm stages (interstadials) of the late Pleistocene. When comparing our results with those obtained from other South American regions, we find that the diet of this particular Chilean megafauna appears to have been more influenced by resource availability than by the potential dietary range of the taxa.

Chemosensory perception and medicinal plants for digestive ailments in a Mapuche community in NW Patagonia, Argentina.

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Molares, Soledad; Ladio, Ana

2009-06-25

To document the richness of plant species used in gastrointestinal disorders and to investigate about the criteria of aroma and flavor associated with its recognition, classification, selection and use. Ethnobotanical fieldwork consisted of interviews to 30 inhabitants living in a Mapuche community of Northwestern Patagonia; data collected was analyzed by means of non-parametric statistics. This work records 75 ethnospecies, pertaining to 40 botanic families. Lamiaceae, Asteraceae and Chenopodiaceae were the most frequently mentioned and described in terms of smell and taste. Most of species (69%) have notable aroma and/or flavor characteristics. The species presenting highest consensus in the population are positively associated with a higher frequency of organoleptic descriptions. In addition, local people consider these perceptions to be potentially useful in the search for substitutes when species are scarce or disappear from a locality. It is possible to establish a preliminary system of classification of medicinal plants based on their organoleptic characteristics and relate this to their effects on health. Moreover the cultural interpretation of smell and taste is of great heuristic importance to ethnopharmacology, in that it indicates which plants are most likely to contain the main active ingredients sought.

Do native grazers from Patagonia, Argentina, consume the invasive kelp Undaria pinnatifida? ¿Pueden los pastoreadores nativos de Patagonia, Argentina, consumir al alga invasora Undaria pinnatifida?

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S. Valeria Teso

2009-06-01

Full Text Available The invasive kelp Undaria pinnatifida (Phaeophyceae, Laminariales was first reported in Golfo Nuevo in 1992 and since then it has spread widely over more than 170 km, all along the northern Patagonian coast, Argentina. Field observations in the region have indicated the potential role of invertebrate grazers, like the sea urchins Arbacia dufresnii and Pseudechinus magellanicus and the gastropod Tegula patagonica, in controlling algal density. Laboratory experiments were conducted to ascertain whether, and if so, to what extent these grazers actually feed on the algae. The studied sea urchins fed on the alga, whereas the snail scraped off biofouling adhered to its surface. Higher densities of grazers were observed on the kelp during summer and might be attributed to increasing in metabolism with increasing temperature, and degradation of blades and sporophylls, which possibly increase their palatability.El alga invasora Undaria pinnatifida (Phaeophyceae, Laminariales fue reportada por primera vez en Golfo Nuevo en 1992, dispersándose ampliamente a lo largo de 170 km de costa en el norte de la Patagonia, Argentina. Observaciones de campo hechas en los erizos de mar Arbacia dufresnii y Pseudechinus magellanicus y en el gasterópodo Tegula patagonica evidenciaron que son posibles consumidores de Undaria pinnatifida en la población local. Se realizaron experimentos de laboratorio con el objetivo de probar si estos pastoreadores eran capaces de consumir el alga. Los erizos de mar estudiados consumen el alga, mientras que el gasterópodo ramonea los epibiontes presentes sobre su superficie. Altas densidades de ramoneadores fueron encontradas sobre el alga durante el verano y podrían ser atribuidas a un aumento del su metabolismo con el aumento de la temperatura y a la degradación de las láminas y esporofilos, lo cual posiblemente aumente la palatabilidad del alga.

Saturación del carbonato de calcio en un área de cultivo de mitílidos en el Seno Reloncaví, Patagonia norte, Chile

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Emilio Alarcón

2015-05-01

Full Text Available Se realizaron mediciones de temperatura, salinidad, alcalinidad total y carbono inorgánico disuelto del agua de mar superficial dentro de un área dedicada a la producción de semillas de mitílidos en el Seno de Reloncaví, Patagonia norte, durante el otoño (mayo 2012 y el verano austral (enero 2013. Se determinó que el estado de saturación del carbonato de calcio (ΩCaCO3 dentro del área de estudio fue bajo (Ωaragonita < 2, inclusive con aguas superficiales "corrosivas" para el CaCO3 (i.e., aguas subsaturadas, Ω < 1, cuando aguas de baja salinidad (<28 y alcalinidad total (<1.800 μmol kg-1 fueron advectadas dentro del centro de producción en mayo de 2012. En enero 2013 la baja salinidad (<25 fue asociada a aguas de baja alcalinidad total (ca. 1700 μmol kg-1 provocando bajos niveles de Ωaragonita en aguas superficiales equilibradas totalmente con la atmósfera (i.e., 400 μatm. Así, se sugiere que eventos corrosivos para el CaCO3 (i.e., aguas subsaturads Ω < 1 pueden ser una condición frecuente en esta área de producción de mitílidos en la Patagonia norte. La potencial disminución en productividad de Mytilus chilensis asociados a la acidificación del océano (AO recientemente descrita por Navarro et al. (2013 y la detección de aguas corrosivas para el carbonato de calcio encontradas, sugieren la necesidad de incluir el monitoreo regular del sistema carbonatos como una variable clave para la evaluación de la capacidad de carga de este sistema de aguas interiores.

Uso del agua y productividad de los bosques nativos e implantados en el NO de la Patagonia: aproximaciones desde la ecohidrología y la ecofisiología

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Gyenge, Javier E; Fernández, M Elena; Licata, Julián; Weigandt, Mariana; Bond, Barbara J; Schlichter, Tomás M

2011-01-01

Existe preocupación por el posible uso excesivo de agua de las forestaciones con especies exóticas de rápido crecimiento en comparación con las especies nativas a las cuales reemplazan en la región NO de la Patagonia. Debido a ello, se han realizado estudios de productividad, consumo y eficiencia en el uso del agua tanto en plantaciones de especies exóticas como en sistemas vegetales naturales en zonas con distintos niveles de déficit hídrico. Esto se llevó a cabo mediante aproximaciones ecoh...

Biological invasion of Pinus ponderosa and Pinus contorta: case study of a forest plantation in Northwestern Patagonia; Invasion biologica de Pinus ponderosa y Pinus contorta: estudio de caso de una plantacion en la Patagonia noroccidental

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Dezzotti, A.; Sbrancia, R.; Mortoro, A.; Monte, C.

2009-07-01

In the Southern Hemisphere, Pinus species from plantations can bring about processes of biological invasion that cause significant and permanent changes on the structure and functioning of surrounding natural ecosystems. The invasive character of Pinus ponderosa (P) and Pinus contorta (C) was examined for a 20-year old plantation located in the Alicura Forest Station (40 degree centigrade 40' S and 71 degree centigrade 00' W), through the analysis of abundance, age and spatial structures, and dispersal of natural regeneration. Seedlings and saplings were located largely within the plantation boundaries, and exhibited a density of 6.9 ind / ha (41 % for P and 59 % for C), a clustered spatial pattern with clumps dispersed not randomly, and a mean dispersal rate of 9.5 m / yr for P. ponderosa and 5.4 m / yr for P. contorta. Both species were invading the adjacent area, according to technical criteria based on ecological responses. However, regeneration niche is strongly hindering tree establishment and dispersal, probably due to high plant cover, presence of vertic soils, and absence of ectomycorrhizal fungi. These results can contribute to predict the capability of P. contorta and P. ponderosa to become invasive, in order to maximize the positive balance of forestry based on these species in northwestern Patagonia. (Author) 50 refs.

The youngest South American rhynchocephalian, a survivor of the K/Pg extinction.

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Apesteguía, Sebastián; Gómez, Raúl O; Rougier, Guillermo W

2014-10-07

Rhynchocephalian lepidosaurs, though once widespread worldwide, are represented today only by the tuatara (Sphenodon) of New Zealand. After their apparent early Cretaceous extinction in Laurasia, they survived in southern continents. In South America, they are represented by different lineages of Late Cretaceous eupropalinal forms until their disappearance by the Cretaceous/Palaeogene (K/Pg) boundary. We describe here the only unambiguous Palaeogene rhynchocephalian from South America; this new taxon is a younger species of the otherwise Late Cretaceous genus Kawasphenodon. Phylogenetic analysis confirms the allocation of the genus to the clade Opisthodontia. The new form from the Palaeogene of Central Patagonia is much smaller than Kawasphenodon expectatus from the Late Cretaceous of Northern Patagonia. The new species shows that at least one group of rhynchocephalians not related to the extant Sphenodon survived in South America beyond the K/Pg extinction event. Furthermore, it adds to other trans-K/Pg ectotherm tetrapod taxa, suggesting that the end-Cretaceous extinction affected Patagonia more benignly than the Laurasian landmasses. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Allochthonous subsidies of organic matter across a lake-river-fjord landscape in the Chilean Patagonia: Implications for marine zooplankton in inner fjord areas

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Vargas, Cristian A.; Martinez, Rodrigo A.; San Martin, Valeska; Aguayo, Mauricio; Silva, Nelson; Torres, Rodrigo

2011-03-01

Ecosystems can act as both sources and sinks of allochthonous nutrients and organic matter. In this sense, fjord ecosystems are a typical interface and buffer zone between freshwater systems, glaciated continents, and the coastal ocean. In order to evaluate the potential sources and composition of organic matter across fjord ecosystems, we characterized particulate organic matter along a lake-river-fjord corridor in the Chilean Patagonia using stable isotope (δ 13C) and lipid (fatty acid composition) biomarker analyses. Furthermore, estimates of zooplankton carbon ingestion rates and measurements of δ 13C and δ 15N in zooplankton (copepods) were used to evaluate the implications of allochthonous subsidies for copepods inhabiting inner fjord areas. Our results showed that riverine freshwater flows contributed an important amount of dissolved silicon but, scarce nitrate and phosphate to the brackish surface layer of the fjord ecosystem. Isotopic signatures of particulate organic matter from lakes and rivers were distinct from their counterparts in oceanic influenced stations. Terrestrial allochthonous sources could support around 68-86% of the particulate organic carbon in the river plume and glacier melting areas, whereas fatty acid concentrations were maximal in the surface waters of the Pascua and Baker river plumes. Estimates of carbon ingestion rates and δ 13C in copepods from the river plume areas indicated that terrestrial carbon could account for a significant percentage of the copepod body carbon (20-50%) during periods of food limitation. Particulate organic matter from the Pascua River showed a greater allochthonous contribution of terrigenous/vascular plant sources. Rivers may provide fjord ecosystems with allochthonous contributions from different sources because of the distinct vegetation coverage and land use along each river's watershed. These observations have significant implications for the management of local riverine areas in the context of

Monopolizar la violencia en una frontera colonial. Policías y militares en Patagonia austral (Argentina y Chile, 1870-1922

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Alberto Harambour R.

2016-01-01

Full Text Available Este artículo analiza la monopolización de la violencia en el ciclo inicial de colonización de Patagonia austral para lo cual propone, primero, que la precariedad local de los Estados de Argentina y Chile descansó en la fuerza expansiva de la industria ganadera para la instalación de su sobe- ranía territorial; y segundo, que la clausura de la delimitación fronteriza solo se produjo en el verano de 1922, como resultado de la represión a la insurgencia obrera. A partir de una extensa investigación en fuentes oficiales y empresariales referidas a Santa Cruz, Magallanes y Tierra del Fuego, así como en la prensa local, se investiga y compara la presencia de la fuerza policial y militar en las subdivisiones administrativas del extremo sur; además se examinaron similitudes y diferencias en las estra- tegias de control social.

Bedrock morphology and structure, upper Santa Cruz Basin, south-central Arizona, with transient electromagnetic survey data

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Bultman, Mark W.; Page, William R.

2016-10-31

The upper Santa Cruz Basin is an important groundwater basin containing the regional aquifer for the city of Nogales, Arizona. This report provides data and interpretations of data aimed at better understanding the bedrock morphology and structure of the upper Santa Cruz Basin study area which encompasses the Rio Rico and Nogales 1:24,000-scale U.S. Geological Survey quadrangles. Data used in this report include the Arizona Aeromagnetic and Gravity Maps and Data referred to here as the 1996 Patagonia Aeromagnetic survey, Bouguer gravity anomaly data, and conductivity-depth transforms (CDTs) from the 1998 Santa Cruz transient electromagnetic survey (whose data are included in appendixes 1 and 2 of this report).Analyses based on magnetic gradients worked well to identify the range-front faults along the Mt. Benedict horst block, the location of possibly fault-controlled canyons to the west of Mt. Benedict, the edges of buried lava flows, and numerous other concealed faults and contacts. Applying the 1996 Patagonia aeromagnetic survey data using the horizontal gradient method produced results that were most closely correlated with the observed geology.The 1996 Patagonia aeromagnetic survey was used to estimate depth to bedrock in the upper Santa Cruz Basin study area. Three different depth estimation methods were applied to the data: Euler deconvolution, horizontal gradient magnitude, and analytic signal. The final depth to bedrock map was produced by choosing the maximum depth from each of the three methods at a given location and combining all maximum depths. In locations of rocks with a known reversed natural remanent magnetic field, gravity based depth estimates from Gettings and Houser (1997) were used.The depth to bedrock map was supported by modeling aeromagnetic anomaly data along six profiles. These cross sectional models demonstrated that by using the depth to bedrock map generated in this study, known and concealed faults, measured and estimated magnetic

Range expansion of Oligoryzomys longicaudatus (Rodentia, Sigmodontinae in Patagonian Chile, and first record of Hantavirus in the region Ampliación del rango de distribución de Oligoryzomys longicaudatus (Rodentia, Sigmodontinae en la Patagonia de Chile y primer registro de Hantavirus en la región

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SEBASTIÁN BELMAR-LUCERO

2009-06-01

Full Text Available At present, 20 species of Oligoryzomys (Rodentia, Sigmodontinae are recognized in the Neotropical region, most of them distinguished by their karyotypes, which fluctuates between 46-70 chromosomes. Two species are currently recognized in Chile, Oligoryzomys longicaudatus (Bennet, 1832; "colilargo" or the long-tailed pygmy rice rat; 2n = 56, which ranges from 27° to approximately 51° S, and O. magellanicus (Bennet, 1836; Magellanic pygmy rice rat; 2n = 54, south of 51° S in the Patagonian region of Chile and Argentina. As part of an ongoing research on the southern Patagonia of Chile, we report the results of small mammal samplings in six localities. We karyotyped 28 specimens and we also sequenced the hypervariable mtDNA region I in 22 individuals, aligning these sequences with an under development phylogeny of O. longicaudatus. We also evaluated the serology and viral charge in all captured specimens to detect the presence of antibodies to Andes virus (ANDV through Strip Immunoblot Assay (SIA, and of viral genome by RT-PCR. The results consistently showed that the karyotype of southern Patagonia specimens was 2n = 56, equal to that of O. longicaudatus, and that individuals from this area do not differentiate phylogenetically from those of the northern range of distribution. In addition, the serology showed the presence of antibodies IgG anti-ANDV and of viral genome in heart, kidney, spleen, and lungs of a single specimen of Oligoryzomys from the locality of Fuerte Bulnes in the Magallanes region. We conclude that all specimens trapped south of 51° S correspond to Oligoryzomys longicaudatus, thus expanding the distribution of this specie! from 51° to at least 55° S. The results also extended the disiribution of the Andes strain of Hantavirus to southernmost Patagonia.Actualmente se reconocen 20 especies de Oligoryzomys (Rodentia, Sigmodontinae en la región Neotropical, la mayoría de ellas distinguidas por sus cariotipos, los que fluct

Sexual dimorphism in the mandible of the armadillo Chaetophractus villosus (Desmarest, 1804) (Dasypodidae) from northern Patagonia, Argentina Dimorfismo sexual da mandíbula do tatu Chaetophractus villosus (Desmarest, 1804) (Dasypodidae) do norte da Patagônia Argentina

OpenAIRE

SM. Squarcia; NS. Sidorkewicj; R. Camina; EB. Casanave

2009-01-01

The aim of this study was to study the sexual dimorphism in adult Chaetophractus villosus (Desmarest, 1804), from northern Patagonia, Argentina. Eight mandibular traits were measured in 37 males and 34 females. Univariate and multivariate morphometric analysis were applied to the data set. Results showed that C. villosus was sexually dimorphic, with higher absolute values corresponding to females. The total length of the mandible was the most important variable to discriminate sexes, followed...

Conflicting evolutionary patterns due to mitochondrial introgression and multilocus phylogeography of the Patagonian freshwater crab Aegla neuquensis.

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Brian R Barber

Full Text Available BACKGROUND: Multiple loci and population genetic methods were employed to study the phylogeographic history of the Patagonian freshwater crab Aegla neuquensis (Aeglidae: Decopoda. This taxon occurs in two large river systems in the Patagonian Steppe, from the foothills of the Andes Mountains east to the Atlantic Ocean. METHODOLOGY/PRINCIPAL FINDINGS: A nuclear phylogeny and multilocus nested clade phylogeographic analysis detected a fragmentation event between the Negro and Chico-Chubut river systems. This event occurred approximately 137 thousand years ago. An isolation-with-migration analysis and maximum-likelihood estimates of gene flow showed asymmetrical exchange of genetic material between these two river systems exclusively in their headwaters. We used information theory to determine the best-fit demographic history between these two river systems under an isolation-with-migration model. The best-fit model suggests that the Negro and the ancestral populations have the same effective population sizes; whereas the Chico-Chubut population is smaller and shows that gene flow from the Chico-Chubut into the Negro is four times higher than in the reverse direction. Much of the Chico-Chubut system appears to have only been recently colonized while the Negro populations appear to have been in place for most of the evolutionary history of this taxon. CONCLUSIONS/SIGNIFICANCE: Due to mitochondrial introgression, three nuclear loci provided different phylogeographic resolution than the three mitochondrial genes for an ancient fragmentation event observed in the nuclear phylogeny. However, the mitochondrial locus provided greater resolution on more recent evolutionary events. Our study, therefore, demonstrates the need to include both nuclear and mitochondrial loci for a more complete understanding of evolutionary histories and associated phylogeographic events. Our results suggest that gene flow between these systems, before and after fragmentation

Latest Pleistocene and Holocene glacial events in the Colonia valley, Northern Patagonia Icefield, southern Chile

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Nimick, David A.; Mcgrath, Daniel; Mahan, Shannon; Friesen, Beverly A.; Leidich, Jonathan

2016-01-01

The Northern Patagonia Icefield (NPI) is the primary glaciated terrain worldwide at its latitude (46.5–47.5°S), and constraining its glacial history provides unique information for reconstructing Southern Hemisphere paleoclimate. The Colonia Glacier is the largest outlet glacier draining the eastern NPI. Ages were determined using dendrochronology, lichenometry, radiocarbon, cosmogenic 10Be and optically stimulated luminescence. Dated moraines in the Colonia valley defined advances at 13.2 ± 0.95, 11.0 ± 0.47 and 4.96 ± 0.21 ka, with the last being the first constraint on the onset of Neoglaciation for the eastern NPI from a directly dated landform. Dating in the tributary Cachet valley, which contains an ice-dammed lake during periods of Colonia Glacier expansion, defined an advance at ca. 2.95 ± 0.21 ka, periods of advancement at 810 ± 49 cal a BP and 245 ± 13 cal a BP, and retreat during the intervening periods. Recent Colonia Glacier thinning, which began in the late 1800s, opened a lower-elevation outlet channel for Lago Cachet Dos in ca. 1960. Our data provide the most comprehensive set of Latest Pleistocene and Holocene ages for a single NPI outlet glacier and expand previously developed NPI glacial chronologies.

Pensar una Patagonia con dos océanos: el proyecto de desarrollo de Ezequiel Ramos Mexía

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Susana Bandieri

2009-01-01

Full Text Available Las posibilidades productivas de la región, con escasas condi - ciones para las prácticas agrícolas pero adecuadas para la ganadería extensiva, predominantemente lanar, hicieron finalmente que la inser - ción patagónica se pensara dentro del mismo modelo de crecimiento “hacia afuera” delineado para el conjunto nacional sobre fines del siglo XIX y comienzos de XX. El único intento superador producido en ese período, aunque frustrado, lo constituyó el proyecto de desarro - llo patagónico elaborado por el Ministro de Obras Públicas del presi - dente Figueroa Alcorta, Ezequiel Ramos Mexía, concretado en la “Ley de Fomento de los Territorios Nacionales” nº 5.559 del año 1908. El ministro, hijo y nieto de estancieros bonaerenses, tenía una concep - ción amplia en materia de desarrollo económico y, en ese sentido, la Patagonia aparecía como el territorio adecuado para generar algunos cambios en un país que por entonces sólo se pensaba en términos agrícolas y pastoriles.

EXPERIENCIA OBRERA, CONSTRUCCIONES SINDICALES Y OR-GANIZACIONES POLÍTICAS DE LA CLASE OBRERA: LOS TRABA-JADORES DE LA PATAGONIA ARGENTINA DURANTE LA DÉCA-DA DEL ‘80

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Gonzalo Pérez Álvarez

2015-09-01

Full Text Available Exploramos la relación entre experiencia obrera y organización partidaria de los trabajadores, a partir del estudio de la experiencia que desarrolla un conjunto de trabajadores afincados en la Patagonia argentina durante el auge del proyecto de promoción industrial para la región. Para ello describiremos algunas experiencias de organización partidaria de grupos obreros, intentando problematizar la búsqueda que realizan estos trabajadores de construir programas políticos propios, los límites y potencialidades que se expresan y el intento de desarrollar propuestas alternativas a las conducciones sindicales tradicionales. Señalamos los momentos de quiebre de esta experiencia, y la relación que guardan con la transformación en la estructura económica de la región. La consolidación hegemónica del neoliberalismo necesitaba la destrucción de las construcciones que pudiesen plantear proyectos alternativos al del capital financiero.Palabras clave: Experiencia, sindicatos, partidos políticos, clase obrera._________________________We explore the relationship between working experience and party organization of workers, from the study of the experience that develops a set of workers settled in Patagonia Argentina during the rise of industrial promotion project for the region. This will describe some experiences of party organization groups of workers, trying to problematize the search performed by these workers to build own political agendas, the limits and potentialities that are expressed and the attempt to develop al-ternative approaches to traditional union lines. Note the break in time of this experience, and how they relate to the transformation in the economic structure of the region. The hegemonic consolidation of neoliberalism needed destruction of buildings that may pose alternative to finance capital projects.Keywords: Experience, trade unions, political parties, working class.

Especies de Ulva del Golfo San Jorge, Patagonia Argentina: variaciones bioquímicas estacionales - espaciales y su relación con la producción de metabolitos bioactivos

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Analía Verónica Uhrich

Full Text Available Objetivos: Investigar especies de Ulva del Golfo San Jorge, Patagonia Argentina, integrando aspectos bioquímicos, actividad biológica y variaciones estacionales/habitacionales que permitan determinar su potencial aplicación en Salud. Métodos: Las algas se colectaron estacionalmente en playas con y sin contaminación antrópica; se secaron, molieron y extrajeron con etanol. Los extractos se fraccionaron mediante solventes de distinta polaridad. Cada fracción fue caracterizada mediante reacciones químicas cualitativas y cromatografía. Las fracciones ricas en flavonoides se analizaron por HPLC-DAD y los lípidos, por TLC. La actividad biológica se ensayó mediante el test de citotoxicidad de Artemia salina, inhibición de la elongación radicular, inhibición de la xantino oxidasa, actividad antioxidante y antibacteriana. Resultados: Se identificaron Ulva rigida y Ulva lactuca. Ambas evidenciaron flavonoides, taninos, quinonas, lípidos, carbohidratos, esteroides. Los flavonoides resultaron mayoritarios en U. rigida (otoño e invierno y en U. lactuca (primavera e invierno, destacándose kayaflavona. Se detectaron alcaloides en Ulva rigida (verano. Los lípidos fueron mayoritarios en verano; U. lactuca en invierno mostró monogalactosildiacilglicérido y en otoño, digalactosilacilglicérido y fosfatidilcolina. La actividad inhibitoria de la elongación radicular, que presume actividad antitumoral, fue importante y dosis dependiente, destacándose U. rigida de otoño y primavera (DE50= 480 y 520 µg/ml, respectivamente. Las demás bioactividades resultaron escasas o negativas. Conclusiones: Las variaciones metabólicas observadas muestran la importancia de considerar las condiciones espacio - temporales al planificar una colecta de ejemplares para su estudio y/o aplicación. Este primer análisis integral de especies de Ulva de la Patagonia Argentina, evidencia su potencialidad como antitumoral.

Climatology of hail in Argentina

Science.gov (United States)

Mezher, Romina N.; Doyle, Moira; Barros, Vicente

2012-10-01

The annual cycle, annual and seasonal frequency and geographical distribution of hail in Argentina during the 1960-2008 period are examined. Eight regions covering the whole territory were defined based on the correlation of the mean annual hail frequency between all weather stations. Regions lying between 30° and 40°S as well as those dominated by mountains present the highest hail frequencies in Argentina. The eastern and coastal areas of the country experience hail events mainly during springtime but they may start in late winter and continue through the beginning of summer. Events in western and central Argentina also predominate in spring but the maximum frequencies are observed during summer months. Trends in the annual number of hail events calculated for each region indicate that events in northwestern and northeastern Argentina have been increasing as well as in southern Patagonia. On the other hand, in central Argentina, southern Buenos Aires-La Pampa, northern Buenos Aires-Litoral and northern Patagonia trends are negative and statistically significant in the first two regions, basically by the decrease of events during spring and summer.

Peat decomposition records in three pristine ombrotrophic bogs in southern Patagonia

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T. Broder

2012-04-01

Full Text Available Ombrotrophic bogs in southern Patagonia have been examined with regard to paleoclimatic and geochemical research questions but knowledge about organic matter decomposition in these bogs is limited. Therefore, we examined peat humification with depth by Fourier Transformed Infrared (FTIR measurements of solid peat, C/N ratio, and δ¹³C and δ¹⁵N isotope measurements in three bog sites. Peat decomposition generally increased with depth but distinct small scale variation occurred, reflecting fluctuations in factors controlling decomposition. C/N ratios varied mostly between 40 and 120 and were significantly correlated (R² > 0.55, p < 0.01 with FTIR-derived humification indices. The degree of decomposition was lowest at a site presently dominated by Sphagnum mosses. The peat was most strongly decomposed at the driest site, where currently peat-forming vegetation produced less refractory organic material, possibly due to fertilizing effects of high sea spray deposition. Decomposition of peat was also advanced near ash layers, suggesting a stimulation of decomposition by ash deposition. Values of δ¹³C were 26.5 ± 2‰ in the peat and partly related to decomposition indices, while δ¹⁵N in the peat varied around zero and did not consistently relate to any decomposition index. Concentrations of DOM partly related to C/N ratios, partly to FTIR derived indices. They were not conclusively linked to the decomposition degree of the peat. DOM was enriched in ¹³C and in ¹⁵N relative to the solid phase probably due to multiple microbial modifications and recycling of N in these N-poor environments. In summary, the depth profiles of C/N ratios, δ¹³C values, and FTIR spectra seemed to reflect changes in environmental conditions affecting decomposition, such as bog wetness, but were dominated by site specific factors, and are further influenced by ash

High abundance and diversity of consumers associated with eutrophic areas in a semi-desert macrotidal coastal ecosystem in Patagonia, Argentina

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Martinetto, Paulina; Daleo, Pedro; Escapa, Mauricio; Alberti, Juan; Isacch, Juan Pablo; Fanjul, Eugenia; Botto, Florencia; Piriz, Maria Luz; Ponce, Gabriela; Casas, Graciela; Iribarne, Oscar

2010-07-01

Here we evaluated the response to eutrophication in terms of abundance and diversity of flora and fauna in a semi-desert macrotidal coastal system (San Antonio bay, Patagonia, Argentina, 40° 48' S) where signs of eutrophication (high nutrient concentration, seaweed blooms, high growth rate of macroalgae) have been reported. We compared abundances and species composition of macroalgae, small infaunal and epifaunal invertebrates, and birds associated with tidal channels of the San Antonio Bay subject to contrasting anthropogenic influence. Macroalgae were more abundant and diverse in the channel closer to human activity where nutrient concentrations were also higher. In contrast to what others have observed in eutrophic sites, small invertebrates and birds were also more abundant and diverse in the channel with macroalgal blooms and high nutrient concentration. The large water flushing during the tidal cycle could prevent anoxic or hypoxic events, making the environment suitable for consumers. Thus, this could be a case in which eutrophication supports high densities of consumers by increasing food availability, rather than negatively affecting the survival of organisms.

Fluid typing and tortuosity analysis with NMR-DE techniques in volcaniclastic reservoirs, Patagonia/Argentina

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Bustos, Ulises Daniel [Schlumberger Argentina S.A., Buenos Aires (Argentina); Breda, Eduardo Walter [Repsol YPF Comodoro Rivadavia, Chubut (Argentina)

2004-07-01

Alternative hydrocarbon-detection techniques are used to differentiate water from hydrocarbon where resistivity-based methods are difficult to apply, such as freshwater reservoirs and complex lithologies. One of these areas is represented by the complex volcaniclastic freshwater reservoirs in the Golfo San Jorge basin, Patagonia Argentina, where water and oil have often identical response on conventional logs. Some advances in hydrocarbon identification based on nuclear magnetic resonance (NMR) techniques were achieved in long T1 environments (very light oils, gas) in the Golfo San Jorge basin by previous NMR fluid typing methods. However, since medium to heavy oils are commonly present in these intervals, hydrocarbon detection by such techniques cannot be properly achieved. In addition, restricted diffusion phenomena recognized in these intervals, constitute further complications in fluid typing since its presence have similar response than native oil. To address this problem, a fluid characterization method using NMR Diffusion-Editing techniques and processing/interpretation with D-T2 maps in a suite of NMR measurements was applied. The technique allowed the detection and evaluation of restricted diffusion in these reservoirs, enabling better hydrocarbon characterization in a broad viscosity range (from light to heavy). The method also improved the petrophysical evaluation because restricted diffusion is related to tortuosity in the reservoir. Since the application of this innovative reservoir evaluation method, fluid prognosis vs well completion results was increased from around 68% to around 88% in Golfo San Jorge basin. Moreover, in some of these areas rates above 95% were recently achieved in 2004. (author)

Salud y enfermedad en Patagonia Austral, líneas de análisis, problemas y perspectivas

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Guichón, Ricardo Aníbal

2005-01-01

Full Text Available La dispersión de enfermedades durante el proceso de contacto europeo aborigen en Patagonia Austral es un tema complejo en el cual estamos comenzando a trabajar. Partiendo de algunas consideraciones generales sobre el proceso de ocupación humana en la región se analiza la información sobre: ¿Qué tipos de enfermedades actuaron en momentos pre y post contacto europeo aborigen? ¿Cuál es la muestra osteológica humana disponible y que información tiene asociada? ¿Dónde y cómo aparece el registro biológico humano? Asimismo se hace referencia a algunos avances en dos líneas de trabajo: tafonomía de restos humanos a partir del análisis de propiedades óseas intrínsecas y otra sobre Paleoparasitología. En el marco de proyectos de colaboración con arqueólogos, se señalan los trabajos iniciados en dos sitios: el primer asentamiento español en el estrecho de Magallanes (1584 y La Misión Salesiana "La Candelaria" de Río Grande, Tierra del Fuego. El desafió es coordinar esfuerzos entre bioantropólogos, biólogos, paleopatólogos, paleoparasitólogos, médicos, arqueólogos e historiadores.

Evaluación de la técnica de MSP-PCR para la caracterización molecular de aislamientos de Rhodotorula mucilaginosa provenientes de la Patagonia noroccidental Assessment of the MSP-PCR technique for the molecular characterization of Rhodotorula mucilaginosa isolates from northwestern Patagonia

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D. Libkind

2007-09-01

Full Text Available La identificación rápida de levaduras de origen ambiental o clínico es de importancia para el estudio de la biodiversidad de estos microorganismos y para la detección de posibles patógenos. Rhodotorula mucilaginosa es una levadura ubicua y pigmentada, capaz de producir infecciones en pacientes inmunocomprometidos. En este trabajo se evaluó la utilidad de la técnica de fingerprinting conocida como MSP-PCR (Micro/Minisatellite-Primed PCR en la caracterización e identificación de aislamientos ambientales de R. mucilaginosa provenientes de la Patagonia noroccidental. Sobre la base de sus caracteres fenotípicos, de un total de 200 levaduras pigmentadas se seleccionaron 110 aislamientos que presuntamente corresponderían a la especie R. mucilaginosa. Se evaluaron los iniciadores (GTG5, (GAC5 y M13 en aislamientos representativos, y se seleccionó el iniciador (GTG5 por ser el que permitió una mejor agrupación de los aislamientos pertenecientes a R. mucilaginosa y una mejor diferenciación de éstos con los de especies filogenéticamente próximas. Utilizando dicho iniciador, el 87% de los aislamientos de R. mucilaginosa presentó un perfil de MSP-PCR similar (> 60% al de la cepa de referencia CBS 316T de R. mucilaginosa. La técnica de MSP-PCR resultó efectiva, tanto para caracterizar e identificar un número elevado de aislamientos ambientales de R. mucilaginosa como para detectar polimorfismos en la especie.The rapid identification of environmental or clinical yeast isolates is important for biodiversity studies and the detection of probable pathogens. Rhodotorula mucilaginosa is a ubiquitous and pigmented yeast capable of infecting immunocompromised patients. In this study, we evaluated the Micro/mini satellite-primed PCR (MSP-PCR fingerprinting method for the characterization and identification of R. mucilaginosa isolates from natural environments in northwestern Patagonia. There were selected 110 putative R. mucilaginosa isolates

Cenozoic intraplate tectonics in Central Patagonia: Record of main Andean phases in a weak upper plate

Science.gov (United States)

Gianni, G. M.; Echaurren, A.; Folguera, A.; Likerman, J.; Encinas, A.; García, H. P. A.; Dal Molin, C.; Valencia, V. A.

2017-11-01

Contraction in intraplate areas is still poorly understood relative to similar deformation at plate margins. In order to contribute to its comprehension, we study the Patagonian broken foreland (PBF) in South America whose evolution remains controversial. Time constraints of tectonic events and structural characterization of this belt are limited. Also, major causes of strain location in this orogen far from the plate margin are enigmatic. To unravel tectonic events, we studied the Cenozoic sedimentary record of the central sector of the Patagonian broken foreland (San Bernardo fold and thrust belt, 44°30‧S-46°S) and the Andes (Meseta de Chalia, 46°S) following an approach involving growth-strata detection, U-Pb geochronology and structural modeling. Additionally, we elaborate a high resolution analysis of the effective elastic thickness (Te) to examine the relation between intraplate contraction location and variations in lithospheric strength. The occurrence of Eocene growth-strata ( 44-40 Ma) suggests that contraction in the Andes and the Patagonian broken foreland was linked to the Incaic phase. Detection of synextensional deposits suggests that the broken foreland collapsed partially during Oligocene to early Miocene. During middle Miocene times, the Quechua contractional phase produced folding of Neogene volcanic rocks and olistostrome deposition at 17 Ma. Finally, the presented Te map shows that intraplate contraction related to Andean phases localized preferentially along weak lithospheric zones (Te < 15 km). Hence, the observed strain distribution in the PBF appears to be controlled by lateral variations in the lithospheric strength. Variations in this parameter could be related to thermo-mechanical weakening produced by intraplate rifting in Paleozoic-Mesozoic times.

Primer registro de Naupactus ruizi (Coleoptera: Curculionoidea asociado con Pinus ponderosa (Gymnospermae: Pinaceae en Patagonia First record of Naupactus ruizi (Coleoptera: Curculionoidea associated to Pinus ponderosa (Gymnospermae: Pinaceae in Patagonia

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Cecilia A. Gómez

2006-07-01

Full Text Available Naupactus ruizi (Brèthes es un gorgojo de rostro corto, distribuido en la Argentina y Chile, que habita en ambientes áridos asociado con vegetación xerofítica y alcanza el rango más austral entre los miembros de la tribu Naupactini. Un relevamiento de insectos y de patógenos como plagas potenciales, realizado durante el 2005 en plantaciones de Pinus spp. en la Patagonia andina argentina, resultó en el hallazgo de adultos de N. ruizi que se alimentaban de acículas de Pinus ponderosa Dougl. ex Laws. Este hallazgo es sorprendente dado que las especies de Naupactini, consumen casi exclusivamente angiospermas. Interpretamos que el cambio de huésped, habría ocurrido como consecuencia de una colonización reciente favorecida por la amplia distribución geográfica del gorgojo y su capacidad para sobrevivir en hábitats marginales, donde probablemente las plantas nativas son escasas y el nuevo huésped presenta una gran abundancia local.Naupactus ruizi (Brèthes is a broad-nosed weevil recorded from Argentina and Chile , that inhabits arid environments with xerophitic vegetation and reaches the southern most distribution of the tribe Naupactini. A survey of potential insect pests and pathogens of plantations of Pinus spp. and other forest species, conducted during 2005 in Argentinean Patagonian Andean forestations, allowed to find N. ruizi feeding on pine needles of Pinus ponderosa Dougl. ex Laws. This finding was unexpected, since species of Naupactini consume almost exclusively angiosperms. We interpret that the new host association may represent a recent host shift, probably facilitated by the broad range of the weevil, its capacity to survive in marginal habitats where natural hosts are scarce, and the local abundance of the new host.

Solapamiento trófico entre el lobo marino de un pelo Otaria flavescens y la pesquería de arrastre demersal del golfo San Matías, Patagonia, Argentina Trophic overlap between the South American sea lion Otaria flavescens and the demersal trawl fishery in San Matías Gulf, Patagonia, Argentina

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María Alejandra Romero

2011-07-01

Full Text Available A nivel internacional, paralelo a la declinación y al colapso de pesquerías de gran escala, surgió un interés creciente por el estudio de las interacciones entre mamíferos marinos y pesquerías. El golfo San Matías (Patagonia, Argentina es considerado un ecosistema pesquero independiente de las aguas de la Plataforma Continental Argentina, con condiciones oceanográficas y biológicas particulares. La condición de sistema semi-cerrado podría generar escenarios particulares para la interacción entre la flota pesquera de arrastre de fondo y la población de lobos marinos de un pelo Otaria flavescens. En el presente trabajo se caracterizó la dieta del predador y la composición de las capturas pesqueras a fin de evaluar el solapamiento trófico entre ambos componentes. A partir de este análisis y la comparación de las tallas de las presas consumidas, se encontró que la posibilidad de una interacción competitiva entre la flota pesquera y los lobos marinos, a partir de la utilización de recursos similares, sería baja en el ecosistema del golfo San Matías.As world fisheries began to decline and massive collapses were observed, the competition between marine mammals and fisheries became an issue of growing concern. San Matías Gulf (Patagonia, Argentina is considered to be a fishery ecosystem independent of the Argentine Continental Shelf waters, with particular oceanographic and biological properties. As a semi-enclosed ecosystem, this gulf may generate particular scenarios for interactions between the demersal trawl fishery fleet and the population of South American sea lions Otaria flavescens. In this paper, the diet of the top predator and the composition of fishery catches were characterized in order to assess the trophic overlap between these two components. This analysis and a comparison of the sizes of prey consumed revealed a low probability of competition for similar resources between the fishing fleet and the marine mammals

El origen y evolución temprana de las serpientes : Análisis anatómico y filogenético de los ofidios cretácicos y paleógenos de la Patagonia y Bolivia

OpenAIRE

Scanferla, Carlos Agustín

2010-01-01

Este trabajo de tesis doctoral tiene como objetivo principal el análisis de dos relevantes escamados procedentes del Cretácico Superior de la Patagonia Argentina, Najash rionegrina y Dinilysia patagonica, como así también dos nuevas serpientes avanzadas del grupo de los Macrostomata, (denominados Taxón A y B) procedentes de la localidad del Terciario Inferior (Paleoceno) de Tiupampa, Bolivia. Se realizó un análisis anatómico detallado de estos taxones fósiles en conjunto con un gran número de...

Heavy metal and trace elements in riparian vegetation and macrophytes associated with lacustrine systems in Northern Patagonia Andean Range.

Science.gov (United States)

Juárez, Andrea; Arribére, María A; Arcagni, Marina; Williams, Natalia; Rizzo, Andrea; Ribeiro Guevara, Sergio

2016-09-01

Vegetation associated with lacustrine systems in Northern Patagonia was studied for heavy metal and trace element contents, regarding their elemental contribution to these aquatic ecosystems. The research focused on native species and exotic vascular plant Salix spp. potential for absorbing heavy metals and trace elements. The native species studied were riparian Amomyrtus luma, Austrocedrus chilensis, Chusquea culeou, Desfontainia fulgens, Escallonia rubra, Gaultheria mucronata, Lomatia hirsuta, Luma apiculata, Maytenus boaria, Myrceugenia exsucca, Nothofagus antarctica, Nothofagus dombeyi, Schinus patagonicus, and Weinmannia trichosperma, and macrophytes Hydrocotyle chamaemorus, Isöetes chubutiana, Galium sp., Myriophyllum quitense, Nitella sp. (algae), Potamogeton linguatus, Ranunculus sp., and Schoenoplectus californicus. Fresh leaves were analyzed as well as leaves decomposing within the aquatic bodies, collected from lakes Futalaufquen and Rivadavia (Los Alerces National Park), and lakes Moreno and Nahuel Huapi (Nahuel Huapi National Park). The elements studied were heavy metals Ag, As, Cd, Hg, and U, major elements Ca, K, and Fe, and trace elements Ba, Br, Co, Cr, Cs, Hf, Na, Rb, Se, Sr, and Zn. Geochemical tracers La and Sm were also determined to evaluate contamination of the biological tissues by geological particulate (sediment, soil, dust) and to implement concentration corrections.

Assessing the impact of plantation forestry on plant biodiversity

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Andreas Ch. Braun

2017-04-01

Full Text Available Effects of plantation forestry on biodiversity are controversially discussed in literature. While some authors stress positive effects, others tend to attribute a largely negative influence to plantations. One important factor steering the influence on biodiversity are management practices. A second important factor is the environmental matrix. Chile offers the option to analyse both factors jointly. The coastal range of central Chile has experienced rapid and widespread replacement of native Nothofagus spp. forests in favour of Pinus radiata plantations. Here, native forests remain limited to small patches surrounded by an environmental matrix of plantations. Management is rather intensive and not designed to maintain biodiversity. While in the coastal range of central Chile the transformation from native forests to non-native tree plantations has almost come to an end, spatial extension of P. contorta and P. ponderosa plantations has just recently begun in Chilean Patagonia. While the management is similar to central Chile, plantations rather exist as small patches surrounded by an environmental matrix of native plant formations (e.g. Nothofagus spp. forests and Nothofagus spp. scrublands. In the framework of this work, effects of the two diametric land usages on biodiversity are assessed and compared. Biodiversity is assessed at the α-, β- and γ-scale. At the α-scale, biodiversity impacts are inferred statistically, using one-way ANOVA and Tukey’s PostHoc test. Biodiversity of plants at both sites is significantly reduced in plantations when compared to native forests or scrublands. Plantation forestry lowers α-biodiversity and does not provide additional habitats for specialists. At the β-scale, weak edge effects due to the presence of native forests are observed. In total, plantation forestry tends to promote plant invasions and impairs the survival of endemics. At the γ-scale, plant species communities where predominantly native

La materia orgánica particulada: comparación de métodos para su determinación y su valor como indicador de calidad de suelos del Chubut Particulate organic-matter: a comparison of methods for its determination and its role as an indicator of soil quality for some soils in the province of Chubut

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Lina Sonia Videla

2008-12-01

Full Text Available La materia orgánica particulada (MOP es un componente dinámico del suelo, que responde selectiva y rápidamente a los cambios de manejo y distintos tipos de disturbios. El objetivo de este estudio fue comparar dos técnicas de determinación de MOP en distintos suelos y evaluar el potencial de esta variable como indicadora de calidad de los mismos. Se estudiaron tres sitios ecológicos de la provincia del Chubut con distinto manejo o afectados por distintos disturbios: Media Luna Clausura (ML C, Media Luna Pastoreo (ML P, Puerto Madryn bioperturbado (PM B, Puerto Madryn no bioperturbado (PM NB, Punta Ninfas no erosionado (PN NE y Punta Ninfas erosionado (PN E. En muestras de suelos extraídas de 0 a 5 cm (PM y PN y de 0 a 10 cm (ML de profundidad se determinó la materia orgánica total (MOT y la MOP por vía húmeda (MOPh (Método Walkley y Black y por ignición en mufla (MOPi a 430 °C. En los Molisoles de ML y en los Aridisoles de PM la MOPi fue mayor que la MOPh, mientras que para los Aridisoles de PN no se registraron diferencias significativas entre los dos métodos. Para los suelos con carbonatos (PM o con alofanos (ML, el método por ignición sobreestimó los contenidos de MOP. La MOT presentó una alta correlación con la MOPh y con la MOPi para todos los suelos en conjunto (r² = 0,89 y r² = 0,73, respectivamente. El suelo que presentó una mayor relación MOP/MOT fue PN NE. En contraste, el suelo PN E, mostró los valores más bajos para esta relación, lo que indicaría, por un lado, que la poca MO que contienen estos suelos está predominantemente asociada a la fracciónParticulate organic-matter (MOP is a dynamic soil component that quickly and selectively responds to management changes and to different disturbance regimes. We compared two techniques to determine the MOP content in different soils and assessed the potential of this variable as an indicator of soil quality. We studied the soils of three ecological sites located

The cephalic lateral line system of temperate perches (Perciformes: Percichthyidae from Argentinean Patagonia

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Rocío M. Vega

Full Text Available ABSTRACT The species of Percichthys (Percichthyidae are endemic to southern South America. Some authors have pointed out that the genus includes four valid species, based on the morphology of the head, jaws, and fins. A phylogenetic analysis published by other authors suggests that three of them are morphotypes belonging to the same species, Percichthys trucha (Valenciennes, 1833. The aim of this study is to describe for the first time the morphology of the cephalic seismosensory system of Patagonian perches, and how these characters vary in the three morphotypes, in order to provide morphological elements to analyze the taxonomy of these fish species. Comparisons of the cephalic seismosensory system between juveniles and adults were also conducted. Juvenile and adult specimens were collected in the northwestern Argentinean Patagonia. Specimens were bleached in 5% H2O2 and the canal systems of their cephalic lateral line were filled with hematoxylin. Specimens were deposited in the Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Argentina. The cephalic lateral line of the studied specimens is a widened type of canal systems, is not connected to the trunk lateral line, and consists of preopercular-mandibular canal, infraorbital canal, supraorbital canal, temporal canal, supratemporal canal, and a supraorbital commisure. The number of pores increases during the ontogeny, while their diameters decrease. The number, position and size of infraorbital canal pores showed significant differences among morphotypes and juveniles. The interpopulation variation regarding the number, position, and size of pores seems to signal an ongoing process of speciation, which is the result adaptations to different environmental conditions. Our study contributes to the knowledge of the morphology of percichthids and describes for the first time the seismosensory system of temperate perches.

LA PATAGONIA COMO TERRITORIO EN DISPUTA: TENSIONES ENTRE EL ESTADO, LA IGLESIA Y LA CONGREGACIÓN SALESIANA POR EL ESPACIO MISIONERO

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María Nicoletti

2012-06-01

Full Text Available La Patagonia fue el primer territorio salesiano “ad gentes”. La creación de su administración bajo la figura de un Vicariato y Prefectura apostólica de parte de la Congregación Salesiana y el Colegio de Propaganda Fide, trajo aparejados numerosos conflictos con las Iglesias Argentina y Chilena y con ambos Estados nacionales. Estos conflictos, en el marco histórico de la construcción de las naciones del siglo XIX y principios del siglo XX, fueron acompañados por los planes de evangelización que la Congregación salesiana había formulado para los pueblos originarios. Bajo la gestión y dirección de los dos primeros rectores mayores de la Congregación, Don Bosco y Don Rua, se resolvieron los problemas con las Iglesias y Estados de ambas naciones, cargados de tensiones en la construcción del territorio de evangelización considerado según cada institución como “terra nullius”, “territorio salesiano” o “territorio nacional y diocesano”.

Levels of essential and toxic elements in Porphyra columbina and Ulva sp. from San Jorge Gulf, Patagonia Argentina

International Nuclear Information System (INIS)

Perez, Adriana Angela; Farias, Silvia Sara; Strobl, Analia Mabel; Perez, Laura Beatriz; Lopez, Clara Magdalena; Pineiro, Adriana; Roses, Otmaro; Fajardo, Maria Angelica

2007-01-01

Baseline concentration levels of As, B, Ca, Cd, Cr, Cu, Co, Fe, Mg, Mn, Mo, Ni, P, Pb, Se, V, and Zn were determined for Porphyra columbina and Ulva sp. collected from three locations along San Jorge Gulf, in Patagonia Argentina. Elements were quantified by inductively coupled plasma-optical emission spectrometry, with the exception of lead and cadmium in some samples which were determined by electrothermal atomic absorption spectrometry. Three stations with different exposure degree to human activities, Bahia Solano, the mouth of Arroyo La Mata stream and Punta Maqueda, were selected as sampling points. The results showed a wide range of metal retention capacity between the two studied species. Regarding the levels of pollutants found in the researched sites, Punta Maqueda seemed to be less influenced by anthropogenic activities than the other two sites except for Cd. Taking into account their toxicities seasonal variations in Pb and Cd levels were studied in both algae in Punta Maqueda. Maximum concentrations of Cd (9.8 μg g -1 dry wt.) were observed in P. columbina during winter, and maximum levels of Pb (0.82 μg g -1 dry wt.) were detected in Ulva sp. during summer. Legislative and health safety aspects were evaluated for Cd and Pb

Levels of essential and toxic elements in Porphyra columbina and Ulva sp. from San Jorge Gulf, Patagonia Argentina

Energy Technology Data Exchange (ETDEWEB)

Perez, Adriana Angela [Catedras de Toxicologia y Quimica Legal, Biologia y Bromatologia y Nutricion, Universidad Nacional de la Patagonia San Juan Bosco, Chubut (Argentina); Farias, Silvia Sara [Comision Nacional de Energia Atomica, Gerencia de Tecnologia y Medio Ambiente, Buenos Aires (Argentina); Strobl, Analia Mabel [Catedras de Toxicologia y Quimica Legal, Biologia y Bromatologia y Nutricion, Universidad Nacional de la Patagonia San Juan Bosco, Chubut (Argentina); Perez, Laura Beatriz [Catedras de Toxicologia y Quimica Legal, Biologia y Bromatologia y Nutricion, Universidad Nacional de la Patagonia San Juan Bosco, Chubut (Argentina); Lopez, Clara Magdalena [Catedra de Toxicologia y Quimica Legal, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires (Argentina); Pineiro, Adriana [Catedra de Toxicologia y Quimica Legal, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires (Argentina); Roses, Otmaro [Catedra de Toxicologia y Quimica Legal, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires (Argentina); Fajardo, Maria Angelica [Catedras de Toxicologia y Quimica Legal, Biologia y Bromatologia y Nutricion, Universidad Nacional de la Patagonia San Juan Bosco, Chubut (Argentina)]. E-mail: copipat@sinectis.com.ar

2007-04-15

Baseline concentration levels of As, B, Ca, Cd, Cr, Cu, Co, Fe, Mg, Mn, Mo, Ni, P, Pb, Se, V, and Zn were determined for Porphyra columbina and Ulva sp. collected from three locations along San Jorge Gulf, in Patagonia Argentina. Elements were quantified by inductively coupled plasma-optical emission spectrometry, with the exception of lead and cadmium in some samples which were determined by electrothermal atomic absorption spectrometry. Three stations with different exposure degree to human activities, Bahia Solano, the mouth of Arroyo La Mata stream and Punta Maqueda, were selected as sampling points. The results showed a wide range of metal retention capacity between the two studied species. Regarding the levels of pollutants found in the researched sites, Punta Maqueda seemed to be less influenced by anthropogenic activities than the other two sites except for Cd. Taking into account their toxicities seasonal variations in Pb and Cd levels were studied in both algae in Punta Maqueda. Maximum concentrations of Cd (9.8 {mu}g g{sup -1} dry wt.) were observed in P. columbina during winter, and maximum levels of Pb (0.82 {mu}g g{sup -1} dry wt.) were detected in Ulva sp. during summer. Legislative and health safety aspects were evaluated for Cd and Pb.

Obtención de inoculantes bacterianos y evaluación de su aplicación en procesos de biorremediación de suelos contaminados con hidrocarburos policíclicos aromáticos (PAH) de la Patagonia semiárida

OpenAIRE

Madueño, Laura

2013-01-01

El objetivo general del siguiente trabajo es contribuir al mejoramiento de los conocimientos básicos que permitan evaluar y mejorar las tecnologías de biorremediación. Los objetivos específicos son: • Aislar a partir de suelos de la Patagonia semiárida, microorganismos degradadores de PAH capaces de resistir condiciones ambientales de la región. • Evaluar la aplicabilidad de las estrategias ABA de bioaumento sobre la biorremediación de suelos patagónicos contami...

Lake-level variations and tides in Lago Argentino, Patagonia: insights from pressure tide gauge records

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Andreas Richter

2015-08-01

Full Text Available Based on precise pressure tide gauge observations lake-level records are derived for two sites in Lago Argentino, southern Patagonia, of 2.5 and 1 years of duration. Applying the tools of time series analysis, the principal processes affecting the lake level are identified and quantified. Lake-level changes reflecting variations in lake volume are dominated by a seasonal cycle of 1.2 m in amplitude. Lake-volume changes occur in addition with a daily period in response to melt water influx from surrounding glaciers. Sporadic lake-volume jumps are caused by bursting of the ice dam of Perito Moreno glacier. Water movements in Lago Argentino are dominated by surface seiches reaching 20 cm in amplitude. Lake tides reach a maximum amplitude of 3 mm. The comparison of the tidal signal extracted from the lake-level observations with a model composed of the contributions of body tide and ocean tidal loading indicates a phase shift of 23° which is most likely explained by an 1 hour phase lag of global ocean tide models in the region of the highly fragmented Pacific coast. The comparison of the obtained results with those of a previous study of Lago Fagnano, Tierra del Fuego, allows to relate differences in the hydrological and hydrodynamic processes between both lakes to morphological properties. This leads to a tentative prediction of the lake-level variability to be expected from other great Patagonian lakes. The presented geodetic results shall serve as a starting point for a detailed limnological investigation of these aquatic ecosystems.

Turismo en la Patagonia: Una amenaza para la integridad ecológica del medio natural

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Luis Inostroza Pino

2008-01-01

The tourism in Patagonia is one of the industries of greater growth during the last decade and on which the development of the region of Magallanes is formed. This fever of the nature tourism is articulating to the social group in a deep functional reconversion, the arrival of the tourists grows and the sector is seen with pride by the authorities. Nevertheless one is tourism base on distributed territorial attributes on one of the natural but fragile surroundings of the country , contradiction that originates the present investigation. A comparative analysis between this tourist development sets out and the natural means , a dialectic approach from the landscape ecology by means of the indirect characterization of the ecosystems through their emergent ecological qualities associated to the properties of their fragments ,establishing the space ecological configuration of natural means and comparing it with the intensity of tourist use to that this being put under . The analysis development completely in GIS (Geographic Information System with mathematical fractal witch allows to complement it with other ecological studies of base being generated a powerful tool to orient the protection of our natural patrimony and to articulate it of a sustainable way but with possibly injurious activities. The model allows to establish a pattern of insensible tourist development with the natural means that take control of the last bastions of the ecosystem of Patagonic Andean Forest, excellent ecological areas outside the legal protection of state which shows the urgent necessity of one better territorial management of the preservation and conservation of our special ecological reality.

Seasonal determination of trace and ultra-trace content in Macrocystis pyrifera from San Jorge Gulf (Patagonia) by Total Reflection X-ray Fluorescence

Science.gov (United States)

Salomone, Vanesa N.; Riera, Marina; Cerchietti, Luciana; Custo, Graciela; Muniain, Claudia

2017-05-01

Seaweed have a great capacity to accumulate heavy metals in their tissues. The chemical characterization of seaweed is important due to their use in environmental monitoring and human or animal food. The aim of the present study was to evaluate the multi-elemental composition of seaweed from San Jorge Gulf (Patagonia, Argentina) by Total Reflection X-ray Fluorescence (TXRF). The elements As, Br, Cu, Cr, Fe, Mn, Ni, Pb, Rb, Sr, V and Zn were seasonally analyzed and quantified in blades of Macrocystis pyrifera. TXRF showed to be a suitable technique for simultaneous multi-element analysis in this kind of samples. The results revealed seasonal variations in the chemical content for some elements; arsenic content was maximum in summer and autumn, iron concentration increased to the winter and zinc concentration was maximum in autumn. The sum of principal micronutrients (Fe + Zn + Mn + Cu) varied between 114 and 171 mg k- 1 g dw. The total As concentration ranged between 36 and 66 mg kg- 1. Lead, nickel and copper were not detected.

A Water Resources Management Model to Evaluate Climate Change Impacts in North-Patagonia, Argentina

Science.gov (United States)

Bucciarelli, L. F.; Losano, F. T.; Marizza, M.; Cello, P.; Forni, L.; Young, C. A.; Girardin, L. O.; Nadal, G.; Lallana, F.; Godoy, S.; Vallejos, R.

2014-12-01

Most recently developed climate scenarios indicate a potential future increase in water stress in the region of Comahue, located in the North-Patagonia, Argentina. This region covers about 140,000 km2 where the Limay River and the Neuquén River converge into the Negro River, constituting the largest integrated basins in Argentina providing various uses of water resources: a) hydropower generation, contributing 15% of the national electricity market; b) fruit-horticultural products for local markets and export; c) human and industrial water supply; d) mining and oil exploitation, including Vaca Muerta, second world largest reserves of shale gas and fourth world largest reserves of shale-oil. The span of multiple jurisdictions and the convergence of various uses of water resources are a challenge for integrated understanding of economically and politically driven resource use activities on the natural system. The impacts of climate change on the system could lead to water resource conflicts between the different political actors and stakeholders. This paper presents the results of a hydrological simulation of the Limay river and Neuquén river basins using WEAP (Water Evaluation and Planning) considering the operation of artificial reservoirs located downstream at a monthly time step. This study aims to support policy makers via integrated tools for water-energy planning under climate uncertainties, and to facilitate the formulation of water policy-related actions for future water stress adaptation. The value of the integrated resource use model is that it can support local policy makers understand the implications of resource use trade-offs under a changing climate: 1) water availability to meet future growing demand for irrigated areas; 2) water supply for hydropower production; 3) increasing demand of water for mining and extraction of unconventional oil; 4) potential resource use conflicts and impacts on vulnerable populations.

Differential use of the Argentine shelf by wintering adults and juveniles southern giant petrels, Macronectes giganteus, from Patagonia

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Blanco, Gabriela S.; Quintana, Flavio

2014-08-01

To study habitat use and at-sea movements of southern giant petrels (SGP) during non-breeding period, we deployed 15 satellite transmitters (six adults, nine juveniles) at Isla Arce and Isla Gran Robredo colonies in Patagonia, Argentina. Birds were instrumented during 81.4 ± 37 days. Adult birds used 74% of the Argentine shelf concentrating mainly at the shelf break, middle shelf waters, and the surroundings of the colony. After fledging, juveniles spread to the Argentine, Uruguayan and Brazilian shelves within the South Atlantic. Adults alternated at-sea excursions (12 ± 5 days) with periods at the colony of 3 ± 0.3 days. Contrarily, juveniles moved first to the shelf break and then traveled northwards reaching the south of Brazil. There was some spatial overlap between age classes, but only during the first 30 days after juveniles had fledged; thereafter there was not overlap between the areas used by both age classes. The Argentine shelf is widely used by different species offering a suitable environment for foraging; this may be why adults SGP from Patagonian colonies spend all year-round within the Argentine shelf. The identification of used areas of non-breeding SGP fills a gap in the species knowledge contributing not only to the preservation the species, but also to the management of marine areas globally recognized as important for many other Procellariiformes.

Relationships between nuclear magnetic resonance parameters used to characterize weathering spilled oil and soil toxicity in central Patagonia.

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Ríos, Stella Maris; Barquin, Mercedes; Katusich, Ofelia; Nudelman, Norma

2014-01-01

Oil spill in the Central Patagonian zone was studied to evaluate if any relationship exists between the parameters used to characterize weathering spilled oil and soil toxicity for two plant species and to evaluate if the phytotoxicity to local species would be a good index for the soil contamination. Nuclear magnetic resonance (NMR) structural indexes and column chromatography compositional indexes were determined to characterize the oil spill in the soil samples. Bioassays were also carried out using Lactuca sativa L (reference) and Atriplex lampa (native species) as test organisms. Measurements of the total petroleum hydrocarbon (TPH) and the electrical conductivity (EC) of the soil were carried out to evaluate the effect on the bioassays. The principal components analysis of the parameters determined by NMR, compositional indexes, EC, TPH, and toxicology data shows that the first three principal components accounted for the 78% of the total variance (40%, 25%, and 13% for the first, second, and third PC, respectively). A good agreement was found between information obtained by compositional indexes and NMR structural indexes. Soil toxicity increases with the increase of EC and TPH. Other factors, such as, the presence of branched and aromatic hydrocarbons is also significant. The statistical evaluation showed that the Euclidean distances (3D) between the background and each one of the samples might be a better indicator of the soil contamination, compared with chemical criterion of TPH.

An Unusual New Theropod with a Didactyl Manus from the Upper Cretaceous of Patagonia, Argentina

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Apesteguía, Sebastián; Smith, Nathan D.; Juárez Valieri, Rubén; Makovicky, Peter J.

2016-01-01

Background Late Cretaceous terrestrial strata of the Neuquén Basin, northern Patagonia, Argentina have yielded a rich fauna of dinosaurs and other vertebrates. The diversity of saurischian dinosaurs is particularly high, especially in the late Cenomanian-early Turonian Huincul Formation, which has yielded specimens of rebacchisaurid and titanosaurian sauropods, and abelisaurid and carcharodontosaurid theropods. Continued sampling is adding to the known vertebrate diversity of this unit. Methodology/ Principal Findings A new, partially articulated mid-sized theropod was found in rocks from the Huincul Formation. It exhibits a unique combination of traits that distinguish it from other known theropods justifying erection of a new taxon, Gualicho shinyae gen. et sp. nov. Gualicho possesses a didactyl manus with the third digit reduced to a metacarpal splint reminiscent of tyrannosaurids, but both phylogenetic and multivariate analyses indicate that didactyly is convergent in these groups. Derived characters of the scapula, femur, and fibula supports the new theropod as the sister taxon of the nearly coeval African theropod Deltadromeus and as a neovenatorid carcharodontosaurian. A number of these features are independently present in ceratosaurs, and Gualicho exhibits an unusual mosaic of ceratosaurian and tetanuran synapomorphies distributed throughout the skeleton. Conclusions/ Significance Gualicho shinyae gen. et sp. nov. increases the known theropod diversity of the Huincul Formation and also represents the first likely neovenatorid from this unit. It is the most basal tetatanuran to exhibit common patterns of digit III reduction that evolved independently in a number of other tetanuran lineages. A close relationship with Deltadromaeus from the Kem Kem beds of Niger adds to the already considerable biogeographic similarity between the Huincul Formation and coeval rock units in North Africa. PMID:27410683

A revised geographical range for Liolaemus elongates Koslowsky, 1896 (Squamata: Liolaemini in Argentina: review of reported and new-data based distribution with new localities

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Ignacio Minoli

2013-12-01

Full Text Available Estimating the effective geographical ranges of species is central to species-oriented conservation and management. In this paper, we review the geographical distribution of Liolaemus elongatus Koslowsky, 1896 with three new records for northern Chubut and southern Río Negro provinces, Argentina. Based on detailed locality records pooled from multiple data sources, including new records obtained for this study, we revise the range of L. elongatus sensu stricto and provide geographical distribution maps comparing the previously recognized range to that proposed herein. Our results show that L. elongatus possesses a much more limited geographic distribution than previously thought, being restricted to areas south of 38°S latitude; the newly proposed range is merely half the species formerly recognized geographical distribution.

Ignition probability of fine dead surface fuels in native Patagonia forests of Argentina

Energy Technology Data Exchange (ETDEWEB)

Bianchi, L.; Defosse, G. E.

2014-06-01

Aim of study: The Canadian Forest Fire Weather Index (FWI) is being implemented all over the world. This index is being adapted to the Argentinean ecosystems since the year 2000. With the objective of calibrating the Fine Fuel Moisture Code (FFMC) of the FWI system to Patagonian forests, we studied the relationship between ignition probability and fine dead surface fuel moisture content (MC) as an indicator of potential fire ignition. Area of study: The study area is located in northwestern Patagonia, Argentina, and comprised two main forest types (cypress and nire) grown under a Mediterranean climate, with a dry summer and precipitations during winter and autumn ({approx}500-800 mm per year). Material and methods: We conducted lab ignition tests fires to determine the threshold of fine dead fuel ignition at different MC levels. Moisture content of dead fine surface fuels in the field was measured every 10-15 days from November to March for three seasons. We calculated the FFMC during these seasons and correlated it with the measured MC by applying a logistic regression model. We combined the results of the ignition tests and of the regressions to suggest FFMC categories for estimating fire danger in Patagonian forests. Main results: The ignition threshold occurred at MC values of 21.5 and 25.0% for cypress and nire sites, respectively. The MC measured varied from 7.3 to 129.6%, and the calculated FFMC varied between 13.4 and 92.6. Highly significant regressions resulted when FFMC was related to MC. The ignition threshold corresponded to a FFMC = 85. We proposed to divide the FFMC scale in three fire danger categories: Low (FFMC {<=} 85), High (85 < FFMC{<=}89) and Extreme (FFMC > 89). Research highlights: Our results provide a useful tool for predicting fire danger in these ecosystems, and are a contribution to the development of the Argentinean Fire Danger Rating and a reference for similar studies in other countries where the FWI is being implemented. (Author)

Checklist of helminths found in Patagonian wild mammals.

Science.gov (United States)

Fugassa, Martin H

2015-09-03

Using available reports, a checklist of the recorded helminth parasites of wild mammals from Patagonia was generated. Records of parasites found in Patagonia were included, together with records from mammals in áreas outside of Patagonia but whose range extends into Patagonia. Information about the host, localities, and references were also included. A total of 1323 records (224 Cestoda, 167 Trematoda, 894 Nematoda, 34 Acanthocephala, and 4 Pentastomida) belonging to 452 helminth species (77 Cestoda, 76 Trematoda, 277 Nematoda, 21 Acanthocephala, and 1 Pentastomida) found in 57 native mammals (22 Rodentia, 4 Didelphimorphia 1 Microbiotheria, 7 Chiroptera, 5 Cingulata, and 13 Carnivora) were listed. However, only 10.6 % of the reports were conducted on samples from Patagonia and corresponded to 25% of mammals in the region. In addition, many studies were made on a few species and, for example, 52% corresponded to studies made on Lama guanicoe. This suggests the need to increase efforts to know the parasitic fauna in a peculiar region as is the Patagonia. This is the first compilation of the helminth parasites of mammals in Argentine Patagonia and is important for parasitological and paleoparasitological studies.

Kelp and dolphin gulls cause perineal wounds in South American fur seal pups (Arctocephalus australis) at Guafo Island, Chilean Patagonia.

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Seguel, Mauricio; Muñoz, Francisco; Montalva, Felipe; Perez-Venegas, Diego; Pavés, Héctor; Gottdenker, Nicole

2017-07-01

During five reproductive seasons, we documented the presence, extent and origin of perineal wounds in South American fur seal pups ( Arctocephalus australis ) on Guafo Island, Northern Chilean Patagonia. The seasonal prevalence of perineal wounds ranged from 5 to 9%, and new cases were more common at the end of the breeding season (February), when pups were on average two months old and were actively expelling hookworms ( Uncinaria sp). Histologically, wounds corresponded to marked ulcerative lymphoplasmacytic and histiocytic dermatitis with granulation tissue and mixed bacterial colonies. In 2015 and 2017, kelp gulls ( Larus dominicanus ) and dolphin gulls ( Leucophaeus scoresbii ) were observed picking and wounding the perineal area of marked pups. This behaviour occurred more frequently after the pups' defecation, when sea gulls engaged in consumption of pups' faeces. The affected pups usually had moderate to marked hookworm infections along with bloody diarrhoea and anaemia. Pups with severe wounds (23% of affected animals) had swollen perineal areas and signs of secondary systemic bacterial infection. We propose that seagulls on Guafo Island have learned to consume remains of blood and parasites in the faeces of pups affected by hookworm infection, causing perineal wounds during this process. We conclude that this perineal wounding is an unintentional, occasional negative effect of an otherwise commensal gull-fur seal relationship.

Discursos Ambientales y Procesos de Fronterización en Patagonia-Aysén (Chile: de los paisajes de la mala hierba a los del bosque sagrado

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Andrés Núñez González

2017-04-01

Full Text Available El texto propone compreder la frontera como el resultado de un proceso de producción social del espacio. En este contexto, el artículo plantea que el territorio de Patagonia-Aysén no es naturalmente fronterizo o marginal sino que aquella condición es el resultado de una producción histórico-geográfica que la fue constituyendo en una espacialidad periférica y que surge en relación al imaginario geográfico producido por y desde la nación. Desde este punto de vista, la agencia estatal desarrolla, mantiene y actualiza vías y estrategias a través de las cuales pueda sostener aquella interpretación fronteriza como justificación para afianzar la ilusión de un espacio homogéneo y común. Analizamos acá dos estrategias: la producción del paisaje ganadero y la del paisaje “verde”.

The early Miocene balaenid Morenocetus parvus from Patagonia (Argentina and the evolution of right whales

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Mónica R. Buono

2017-12-01

Full Text Available Balaenidae (right and bowhead whales are a key group in understanding baleen whale evolution, because they are the oldest surviving lineage of crown Mysticeti, with a fossil record that dates back ∼20 million years. However, this record is mostly Pliocene and younger, with most of the Miocene history of the clade remaining practically unknown. The earliest recognized balaenid is the early Miocene Morenocetus parvus Cabrera, 1926 from Argentina. M. parvus was originally briefly described from two incomplete crania, a mandible and some cervical vertebrae collected from the lower Miocene Gaiman Formation of Patagonia. Since then it has not been revised, thus remaining a frequently cited yet enigmatic fossil cetacean with great potential for shedding light on the early history of crown Mysticeti. Here we provide a detailed morphological description of this taxon and revisit its phylogenetic position. The phylogenetic analysis recovered the middle Miocene Peripolocetus as the earliest diverging balaenid, and Morenocetus as the sister taxon of all other balaenids. The analysis of cranial and periotic morphology of Morenocetus suggest that some of the specialized morphological traits of modern balaenids were acquired by the early Miocene and have remained essentially unchanged up to the present. Throughout balaenid evolution, morphological changes in skull arching and ventral displacement of the orbits appear to be coupled and functionally linked to mitigating a reduction of the field of vision. The body length of Morenocetus and other extinct balaenids was estimated and the evolution of body size in Balaenidae was reconstructed. Optimization of body length on our phylogeny of Balaenidae suggests that the primitive condition was a relatively small body length represented by Morenocetus, and that gigantism has been acquired independently at least twice (in Balaena mysticetus and Eubalaena spp., with the earliest occurrence of this trait in the late

The early Miocene balaenid Morenocetus parvus from Patagonia (Argentina) and the evolution of right whales

Science.gov (United States)

Cozzuol, Mario A.; Fitzgerald, Erich M.G.

2017-01-01

Balaenidae (right and bowhead whales) are a key group in understanding baleen whale evolution, because they are the oldest surviving lineage of crown Mysticeti, with a fossil record that dates back ∼20 million years. However, this record is mostly Pliocene and younger, with most of the Miocene history of the clade remaining practically unknown. The earliest recognized balaenid is the early Miocene Morenocetus parvus Cabrera, 1926 from Argentina. M. parvus was originally briefly described from two incomplete crania, a mandible and some cervical vertebrae collected from the lower Miocene Gaiman Formation of Patagonia. Since then it has not been revised, thus remaining a frequently cited yet enigmatic fossil cetacean with great potential for shedding light on the early history of crown Mysticeti. Here we provide a detailed morphological description of this taxon and revisit its phylogenetic position. The phylogenetic analysis recovered the middle Miocene Peripolocetus as the earliest diverging balaenid, and Morenocetus as the sister taxon of all other balaenids. The analysis of cranial and periotic morphology of Morenocetus suggest that some of the specialized morphological traits of modern balaenids were acquired by the early Miocene and have remained essentially unchanged up to the present. Throughout balaenid evolution, morphological changes in skull arching and ventral displacement of the orbits appear to be coupled and functionally linked to mitigating a reduction of the field of vision. The body length of Morenocetus and other extinct balaenids was estimated and the evolution of body size in Balaenidae was reconstructed. Optimization of body length on our phylogeny of Balaenidae suggests that the primitive condition was a relatively small body length represented by Morenocetus, and that gigantism has been acquired independently at least twice (in Balaena mysticetus and Eubalaena spp.), with the earliest occurrence of this trait in the late Miocene�

Validating numerical simulations of snow avalanches using dendrochronology: the Cerro Ventana event in Northern Patagonia, Argentina

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A. Casteller

2008-05-01

Full Text Available The damage caused by snow avalanches to property and human lives is underestimated in many regions around the world, especially where this natural hazard remains poorly documented. One such region is the Argentinean Andes, where numerous settlements are threatened almost every winter by large snow avalanches. On 1 September 2002, the largest tragedy in the history of Argentinean mountaineering took place at Cerro Ventana, Northern Patagonia: nine persons were killed and seven others injured by a snow avalanche. In this paper, we combine both numerical modeling and dendrochronological investigations to reconstruct this event. Using information released by local governmental authorities and compiled in the field, the avalanche event was numerically simulated using the avalanche dynamics programs AVAL-1D and RAMMS. Avalanche characteristics, such as extent and date were determined using dendrochronological techniques. Model simulation results were compared with documentary and tree-ring evidences for the 2002 event. Our results show a good agreement between the simulated projection of the avalanche and its reconstructed extent using tree-ring records. Differences between the observed and the simulated avalanche, principally related to the snow height deposition in the run-out zone, are mostly attributed to the low resolution of the digital elevation model used to represent the valley topography. The main contributions of this study are (1 to provide the first calibration of numerical avalanche models for the Patagonian Andes and (2 to highlight the potential of Nothofagus pumilio tree-ring records to reconstruct past snow-avalanche events in time and space. Future research should focus on testing this combined approach in other forested regions of the Andes.

Exploring the diversity and antimicrobial potential of marine Actinobacteria from the Comau Fjord in Northern Patagonia, Chile

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Agustina Undabarrena

2016-07-01

Full Text Available Bioprospecting natural products in marine bacteria from fjord environments are attractive due to their unique geographical features. Although Actinobacteria are well known for producing a myriad of bioactive compounds, investigations regarding fjord-derived marine Actinobacteria are scarce. In this study, the diversity and biotechnological potential of Actinobacteria isolated from marine sediments within the Comau fjord, in Northern Chilean Patagonia, were assessed by culture-based approaches. The 16S rRNA gene sequences revealed that members phylogenetically related to the Micrococcaceae, Dermabacteraceae, Brevibacteriaceae, Corynebacteriaceae, Microbacteriaceae, Dietziaceae, Nocardiaceae and Streptomycetaceae families were present at the Comau fjord. A high diversity of cultivable Actinobacteria (10 genera was retrieved by using only five different isolation media. Four isolates belonging to Arthrobacter, Brevibacterium, Corynebacterium and Kocuria genera showed 16S rRNA gene identity <98.7% suggesting that they are novel species. Physiological features such as salt tolerance, artificial sea water requirement, growth temperature, pigmentation and antimicrobial activity were evaluated. Arthrobacter, Brachybacterium, Curtobacterium, Rhodococcus and Streptomyces isolates showed strong inhibition against both Gram-negative Pseudomonas aeruginosa, Escherichia coli and Salmonella enterica and Gram-positive Staphylococcus aureus, Listeria monocytogenes. Antimicrobial activities in Brachybacterium, Curtobacterium and Rhodococcus have been scarcely reported, suggesting that non-mycelial strains are a suitable source of bioactive compounds. In addition, all strains bear at least one of the biosynthetic genes coding for NRPS (91%, PKS I (18% and PKS II (73%.Our results indicate that the Comau fjord is a promising source of novel Actinobacteria with biotechnological potential for producing biologically active compounds.

Patrones de distribución espacial y temporal de floraciones de Alexandrium catenella (Whedon & Kofoid Balech 1985, en aguas interiores de la Patagonia noroccidental de Chile Spatial and temporal distribution patterns of blooms of Alexandrium catenella (Whedon & Kofoid Balech 1985, on inland seas of northwest Patagonia, Chile

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CARLOS MOLINET

2003-12-01

Full Text Available La presencia del dinoflagelado tóxico Alexandrium catenella en las aguas interiores de la Patagonia noroccidental, fue registrada en la década de los 90. A partir de 1995 se iniciaron programas de monitoreo de fitoplancton orientados al seguimiento de este dinoflagelado y sus efectos sobre los mariscos en la Décima y Undécima Región de Chile, financiados por distintas instituciones. Esto permitió recolectar una importante base de datos, aunque incompleta en muchos aspectos debido a la independencia de objetivos de los diferentes estudios. En esta revisión se agruparon todos los datos disponibles para buscar patrones que ayuden a la formulación de hipótesis sobre la dispersión e incidencia espacial y temporal de A. catenella en esta amplia zona y mucho más habitada que la Duodécima Región. Inicialmente se recolectaron muestras mensuales y desde fines de 2000 semanales tanto de fitoplancton como de mariscos en un número de estaciones que varió cada año. Desde fines de 1995 al 2002 se registraron cuatro floraciones de A. catenella, con intensidad y distribución variable, observándose una expansión de la distribución geográfica de esta especie hacia el norte (desde aproximadamente 45° 47' S en 1996 a 42° S, Chiloé en 2002. Las cuatro floraciones registradas fueron marcadamente estacionales, concentradas entre los meses de enero a marzo y coincidieron con los máximos registros del veneno paralizante de los mariscos. Los datos analizados sugieren que el origen de las floraciones de A. catenella en las aguas interiores de la región estaría asociada a la presencia de bancos de quistes, cuyo ciclo de vida se expresa con una variación bianual debido a la variación en condiciones ambientales que favorecen la germinación de estos organismos. La influencia de oscilaciones en el océano adyacente que estarían afectando las características de circulación general de las aguas interiores y las características de la columna de

Revisión sistemática del género Halictillus (Hymenoptera: Halictidae: Augochlorini en la Argentina Systematic revision of the genus Halictillus (Hymenoptera: Halictidae: Augochlorini in Argentina

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Rocío A. González-Vaquero

2010-06-01

Full Text Available Entre los grupos basales de la tribu Augochlorini, se encuentra el género de abejas Halictillus Moure, con sólo dos especies descriptas y ninguna revisión sistemática hasta el momento. En este trabajo, se describen cuatro especies nuevas de Halictillus de la Argentina y Chile. Las especies nuevas son: H. amplilobus sp. nov. (de Buenos Aires, Córdoba y Río Negro, H. peninsularis sp. nov. (de la Península de Valdés, Chubut, H. badiclypeus sp. nov. (de Mendoza, La Rioja y Catamarca y H. reticulatus sp. nov. (de las zonas occidentales de Chubut, Neuquén y Río Negro en la Argentina, y las regiones de La Araucanía y Los Lagos en Chile. Se presenta una clave para la determinación de las seis especies que componen el género, así como descripciones detalladas, imágenes de microscopio electrónico de barrido y un mapa de distribución geográfica de las especies nuevas.Among the basal genera of the tribe Augochlorini is the bee genus Halictillus Moure, which comprises only two described species and has no systematic revision at the moment. Four new species of Halictillus from Argentina and Chile are described in this contribution: H. amplilobus sp. nov. (from Buenos Aires, Córdoba and Río Negro Provinces, H. peninsularis sp. nov. (from Península Valdés, Chubut Province, H. badiclypeus sp. nov. (from Mendoza, La Rioja and Catamarca Provinces and H. reticulatus sp. nov. (from western Chubut, Neuquén and Río Negro Provinces in Argentina, and the regions of La Araucanía and Los Lagos in Chile. A key to the six species of the genus, as well as detailed descriptions, scanning electron microscope images and a map with distributional data of the new species are provided.

OPTICAL FLOW APPLIED TO TIME-LAPSE IMAGE SERIES TO ESTIMATE GLACIER MOTION IN THE SOUTHERN PATAGONIA ICE FIELD

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E. Lannutti

2016-06-01

Full Text Available In this work, we assessed the feasibility of using optical flow to obtain the motion estimation of a glacier. In general, former investigations used to detect glacier changes involve solutions that require repeated observations which are many times based on extensive field work. Taking into account glaciers are usually located in geographically complex and hard to access areas, deploying time-lapse imaging sensors, optical flow may provide an efficient solution at good spatial and temporal resolution to describe mass motion. Several studies in computer vision and image processing community have used this method to detect large displacements. Therefore, we carried out a test of the proposed Large Displacement Optical Flow method at the Viedma Glacier, located at South Patagonia Icefield, Argentina. We collected monoscopic terrestrial time-lapse imagery, acquired by a calibrated camera at every 24 hour from April 2014 until April 2015. A filter based on temporal correlation and RGB color discretization between the images was applied to minimize errors related to changes in lighting, shadows, clouds and snow. This selection allowed discarding images that do not follow a sequence of similarity. Our results show a flow field in the direction of the glacier movement with acceleration in the terminus. We analyzed the errors between image pairs, and the matching generally appears to be adequate, although some areas show random gross errors related to the presence of changes in lighting. The proposed technique allowed the determination of glacier motion during one year, providing accurate and reliable motion data for subsequent analysis.

Large scale hydrogen production from wind energy in the Magallanes area for consumption in the central zone of Chile

International Nuclear Information System (INIS)

Zolezzi, J.M.; Garay, A.; Reveco, M.

2010-01-01

The energy proposal of this research suggests the use of places with abundant wind resources for the production of H 2 on a large scale to be transported and used in the central zone of Chile with the purpose of diversifying the country's energy matrix in order to decrease its dependence on fossil fuels, increase its autonomy, and cover the future increases in energy demand. This research showed that the load factor of the proposed wind park reaches a value of 54.5%, putting in evidence the excellent wind conditions of the zone. This implies that the cost of the electricity produced by the wind park located in the Chilean Patagonia would have a cost of 0.0213 US$ kWh -1 in the year 2030. The low prices of the electricity obtained from the park, thanks to the economy of scale and the huge wind potential, represent a very attractive scenario for the production of H 2 in the future. The study concludes that by the year 2030 the cost of the H 2 generated in Magallanes and transported to the port of Quinteros would be 18.36 US$ MBTU -1 , while by that time the cost of oil would be about 17.241 US$ MBTU -1 , a situation that places H 2 in a very competitive position as a fuel. (author)

Living in an estuary: Commerson's dolphin (Cephalorhynchus commersonii (Lacépède, 1804, habitat use and behavioural pattern at the Santa Cruz River, Patagonia, Argentina

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Rocio Loizaga de Castro

2013-11-01

Full Text Available Commerson's dolphins, Cephalorhynchus commersonii, suffer bycatch in fisheries and are target of dolphin-watching activities along Patagonia. Here we described dolphins' habitat use and behavioural pattern at the estuary of Santa Cruz River. Behavioural observations were made from vantage points using a spotting scope. Boat surveys were conducted randomly from Puerto Santa Cruz to the mouth of the river to analyze the habitat use. The survey area was divided into 1 km² cells and characterized with depth and benthic slope. The described behaviours for the Commerson's dolphin were: travelling, slow travelling, milling, resting, socializing, stationary swimming and diving. A new behavioural context was assigned to diving, a behaviour that showed a high frequency during downing tide, suggesting a benthic foraging strategy. Additionally, we found a strong influence of the tide on Commerson's dolphin behaviour. Habitat use models indicated that dolphins prefer shallow water inside the estuary. The knowledge of the behavioural patterns and the habitat use of these endemic species, in this unexplored area, provide tools for management and conservation purposes.

A 2D hydrodynamic-sedimentological model for gravel-bed rivers. Part I: theory and validation

OpenAIRE

Gabriel Kaless; Mario A. Lenzi; Luca Mao

2013-01-01

This paper presents a novel 2D-depth average model especially developed for gravel-bed rivers, named Lican-Leufú (Lican=pebble and Leufu=river, in Mapuche’s language, the native inhabitants of Central Patagonia, Argentina). The model consists of three components: a hydrodynamic, a sedimentological, and a morphological model. The flow of water is described by the depth-averaged Reynolds equations for unsteady, free-surface, shallow water flows. It includes the standard k-e model for turbulence...

A Large Accumulation of Avian Eggs from the Late Cretaceous of Patagonia (Argentina) Reveals a Novel Nesting Strategy in Mesozoic Birds

Science.gov (United States)

Fernández, Mariela S.; García, Rodolfo A.; Fiorelli, Lucas; Scolaro, Alejandro; Salvador, Rodrigo B.; Cotaro, Carlos N.; Kaiser, Gary W.; Dyke, Gareth J.

2013-01-01

We report the first evidence for a nesting colony of Mesozoic birds on Gondwana: a fossil accumulation in Late Cretaceous rocks mapped and collected from within the campus of the National University of Comahue, Neuquén City, Patagonia (Argentina). Here, Cretaceous ornithothoracine birds, almost certainly Enanthiornithes, nested in an arid, shallow basinal environment among sand dunes close to an ephemeral water-course. We mapped and collected 65 complete, near-complete, and broken eggs across an area of more than 55 m2. These eggs were laid either singly, or occasionally in pairs, onto a sandy substrate. All eggs were found apparently in, or close to, their original nest site; they all occur within the same bedding plane and may represent the product of a single nesting season or a short series of nesting attempts. Although there is no evidence for nesting structures, all but one of the Comahue eggs were half-buried upright in the sand with their pointed end downwards, a position that would have exposed the pole containing the air cell and precluded egg turning. This egg position is not seen in living birds, with the exception of the basal galliform megapodes who place their eggs within mounds of vegetation or burrows. This accumulation reveals a novel nesting behaviour in Mesozoic Aves that was perhaps shared with the non-avian and phylogenetically more basal troodontid theropods. PMID:23613776

A large accumulation of avian eggs from the late cretaceous of patagonia (Argentina) reveals a novel nesting strategy in mesozoic birds.

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Fernández, Mariela S; García, Rodolfo A; Fiorelli, Lucas; Scolaro, Alejandro; Salvador, Rodrigo B; Cotaro, Carlos N; Kaiser, Gary W; Dyke, Gareth J

2013-01-01

We report the first evidence for a nesting colony of mesozoic birds on Gondwana: a fossil accumulation in Late Cretaceous rocks mapped and collected from within the campus of the National University of Comahue, Neuquén City, Patagonia (Argentina). Here, Cretaceous ornithothoracine birds, almost certainly Enanthiornithes, nested in an arid, shallow basinal environment among sand dunes close to an ephemeral water-course. We mapped and collected 65 complete, near-complete, and broken eggs across an area of more than 55 m(2). These eggs were laid either singly, or occasionally in pairs, onto a sandy substrate. All eggs were found apparently in, or close to, their original nest site; they all occur within the same bedding plane and may represent the product of a single nesting season or a short series of nesting attempts. Although there is no evidence for nesting structures, all but one of the Comahue eggs were half-buried upright in the sand with their pointed end downwards, a position that would have exposed the pole containing the air cell and precluded egg turning. This egg position is not seen in living birds, with the exception of the basal galliform megapodes who place their eggs within mounds of vegetation or burrows. This accumulation reveals a novel nesting behaviour in Mesozoic Aves that was perhaps shared with the non-avian and phylogenetically more basal troodontid theropods.

Sequential development of tidal ravinement surfaces in macro- to hypertidal estuaries with high volcaniclastic input: the Miocene Puerto Madryn Formation (Patagonia, Argentina)

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Scasso, Roberto A.; Cuitiño, José I.

2017-08-01

The late Miocene beds of the Puerto Madryn Formation (Provincia del Chubut, Argentina) are formed by shallow marine and estuarine sediments. The latter include several tidal-channel infills well exposed on the cliffy coast of the Peninsula Valdés. The Bahía Punta Fósil and Cerro Olazábal paleochannels are end members of these tidal channels and show a fining-upward infilling starting with intraformational channel lag conglomerates above deeply erosional surfaces interpreted as fluvial ravinement surfaces (the erosion surface formed in the purely fluvial or the fluvially dominated part of the estuary, where erosion is driven by fluvial processes). These are overlain and eventually truncated (and suppressed) by the tidal ravinement surface (TRS), in turn covered with high-energy, bioclastic conglomerates mostly formed in the "tidally dominated/fluvially influenced" part of an estuary. Above, large straight or arcuate point bars with alternatively sandy/muddy seasonal beds and varying trace and body fossil contents were deposited from the freshwater fluvially dominated to saline-water tidally dominated part of the estuary. The upper channel infill is formed by cross-bedded sands with mud drapes and seaward-directed paleocurrents, together with barren, volcaniclastic sandy to muddy heterolithic seasonal rhythmites, both deposited in the fluvially dominated part of the estuary. Volcanic ash driven by the rivers after large explosive volcanic eruptions on land resulted in sedimentation rates as high as 0.9 m per year, preserving (through burial) the morphology of tidal channels and TRSs. The channel deposits were formed in a tide-dominated, macrotidal to hypertidal open estuary with well-developed TRSs resulting from strong tidal currents deeply scouring into the transgressive filling of the channels and eventually cutting the fluvial ravinement surface. The TRSs extended upstream to the inner part of the estuary during long periods of low sedimentation rates

Regional Extinctions and Quaternary Shifts in the Geographic Range of Lestodelphys halli, the Southernmost Living Marsupial: Clues for Its Conservation.

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Anahí E Formoso

Full Text Available The Patagonian opossum (Lestodelphys halli, the southernmost living marsupial, inhabits dry and open environments, mainly in the Patagonian steppe (between ~32 °S and ~49 °S. Its rich fossil record shows its occurrence further north in Central Argentina during the Quaternary. The paleoenvironmental meaning of the past distribution of L. halli has been mostly addressed in a subjective framework without an explicit connection with the climatic "space" currently occupied by this animal. Here, we assessed the potential distribution of this species and the changes occurred in its geographic range during late Pleistocene-Holocene times and linked the results obtained with conservation issues. To this end, we generated three potential distribution models with fossil records and three with current ones, using MaxEnt software. These models showed a decrease in the suitable habitat conditions for the species, highlighting a range shift from Central-Eastern to South-Western Argentina. Our results support that the presence of L. halli in the Pampean region during the Pleistocene-Holocene can be related to precipitation and temperature variables and that its current presence in Patagonia is more related to temperature and dominant soils. The models obtained suggest that the species has been experiencing a reduction in its geographic range since the middle Holocene, a process that is in accordance with a general increase in moisture and temperature in Central Argentina. Considering the findings of our work and the future scenario of global warming projected for Patagonia, we might expect a harsh impact on the distribution range of this opossum in the near future.

Regional Extinctions and Quaternary Shifts in the Geographic Range of Lestodelphys halli, the Southernmost Living Marsupial: Clues for Its Conservation

Science.gov (United States)

Formoso, Anahí E.; Martin, Gabriel M.; Teta, Pablo; Carbajo, Aníbal E.; Sauthier, Daniel E. Udrizar; Pardiñas, Ulyses F. J.

2015-01-01

The Patagonian opossum (Lestodelphys halli), the southernmost living marsupial, inhabits dry and open environments, mainly in the Patagonian steppe (between ~32°S and ~49°S). Its rich fossil record shows its occurrence further north in Central Argentina during the Quaternary. The paleoenvironmental meaning of the past distribution of L. halli has been mostly addressed in a subjective framework without an explicit connection with the climatic “space” currently occupied by this animal. Here, we assessed the potential distribution of this species and the changes occurred in its geographic range during late Pleistocene-Holocene times and linked the results obtained with conservation issues. To this end, we generated three potential distribution models with fossil records and three with current ones, using MaxEnt software. These models showed a decrease in the suitable habitat conditions for the species, highlighting a range shift from Central-Eastern to South-Western Argentina. Our results support that the presence of L. halli in the Pampean region during the Pleistocene-Holocene can be related to precipitation and temperature variables and that its current presence in Patagonia is more related to temperature and dominant soils. The models obtained suggest that the species has been experiencing a reduction in its geographic range since the middle Holocene, a process that is in accordance with a general increase in moisture and temperature in Central Argentina. Considering the findings of our work and the future scenario of global warming projected for Patagonia, we might expect a harsh impact on the distribution range of this opossum in the near future. PMID:26203650

A Basal Lithostrotian Titanosaur (Dinosauria: Sauropoda) with a Complete Skull: Implications for the Evolution and Paleobiology of Titanosauria

Science.gov (United States)

Martínez, Rubén D. F.; Lamanna, Matthew C.; Novas, Fernando E.; Ridgely, Ryan C.; Casal, Gabriel A.; Martínez, Javier E.; Vita, Javier R.; Witmer, Lawrence M.

2016-01-01

We describe Sarmientosaurus musacchioi gen. et sp. nov., a titanosaurian sauropod dinosaur from the Upper Cretaceous (Cenomanian—Turonian) Lower Member of the Bajo Barreal Formation of southern Chubut Province in central Patagonia, Argentina. The holotypic and only known specimen consists of an articulated, virtually complete skull and part of the cranial and middle cervical series. Sarmientosaurus exhibits the following distinctive features that we interpret as autapomorphies: (1) maximum diameter of orbit nearly 40% rostrocaudal length of cranium; (2) complex maxilla—lacrimal articulation, in which the lacrimal clasps the ascending ramus of the maxilla; (3) medial edge of caudal sector of maxillary ascending ramus bordering bony nasal aperture with low but distinct ridge; (4) ‘tongue-like’ ventral process of quadratojugal that overlaps quadrate caudally; (5) separate foramina for all three branches of the trigeminal nerve; (6) absence of median venous canal connecting infundibular region to ventral part of brainstem; (7) subvertical premaxillary, procumbent maxillary, and recumbent dentary teeth; (8) cervical vertebrae with ‘strut-like’ centroprezygapophyseal laminae; (9) extremely elongate and slender ossified tendon positioned ventrolateral to cervical vertebrae and ribs. The cranial endocast of Sarmientosaurus preserves some of the most complete information obtained to date regarding the brain and sensory systems of sauropods. Phylogenetic analysis recovers the new taxon as a basal member of Lithostrotia, as the most plesiomorphic titanosaurian to be preserved with a complete skull. Sarmientosaurus provides a wealth of new cranial evidence that reaffirms the close relationship of titanosaurs to Brachiosauridae. Moreover, the presence of the relatively derived lithostrotian Tapuiasaurus in Aptian deposits indicates that the new Patagonian genus represents a ‘ghost lineage’ with a comparatively plesiomorphic craniodental form, the evolutionary

Nuevo hospedador de Huequenia livida (Coleoptera: Cerambycidae en Argentina New host record for Huequenia livida (Coleoptera: Cerambycidae in Argentina

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José María Villacide

2006-07-01

Full Text Available La presencia de adultos de Huequenia livida (Germain, 1898 (Cerambycidae fue detectada en una plantación de Pinus contorta Douglas ex Loudon var. murrayana (Balf. Engelm. en la localidad de Lago Puelo (Chubut, Argentina. Este es el primer registro del desarrollo de H. livida en una especie hospedadora distinta de Araucaria spp. Esta contribución agrega una nueva especie y una nueva familia al listado de plantas hospedadoras descriptas para este Cerambycidae en Chile.Adult of Huequenia livida (Germain, 1898 (Cerambycidae were captured in a Pinus contorta Douglas ex Loudon var. murrayana (Balf. Engelm. plantation located in Lago Puelo ( Chubut , Argentina . This is the first mention of the development of H. livida on a host species different than Araucaria spp. This contribution also adds a new host species and family to the list of host plants described for this Cerambycidae in Chile .

CRITERIOS ANALÍTICOS PARA EL ESTUDIO DEL CONFLICTO EN EL PASADO. UN CASO DE ESTUDIO EN CAZADORES RECOLECTORES DE NORPATAGONIA / Analytical criteria for the study of conflict in the past. A case study in hunter-gatherers from northeastern Patagonia.

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Florencia Gordón

2015-06-01

Full Text Available La interpretación del conflicto en sociedades del pasado es un proceso ambiguo que puede conducir a subestimar o sobrestimar los niveles de violencia. El objetivo de este trabajo es presentar la metodología aplicada al estudio de los patrones de violencia interpersonal en grupos cazadores-recolectores del Noreste de Patagonia, durante el Holoceno tardío (4000-350 años AP. Si bien la principal línea de evidencia fue bioarqueológica se exploraron líneas independientes y complementarias (i.e. tipos de artefactos potencialmente utilizados en contextos de violencia en la región; información transcultural, etnográfica y etnohistórica relevante. Con el objetivo de conocer la distribución espacio-temporal y sexo-etaria de los traumas se analizó una muestra de cráneos (n=797. Previo al relevamiento de lesiones se evaluó el grado de preservación de las muestras. Para la interpretación de un tipo de traumas particulares (i.e. depresiones lineales se desarrolló un diseño experimental. Las lesiones se describieron macroscópica y microscópicamente. La evaluación estadística se realizó en dos niveles de acuerdo con el grado de ambigüedad de cada lesión. Una metodología basada sobre líneas independientes y complementarias, como así también la utilización de criterios bioarqueológicos y forenses, resultaron ser una herramienta adecuada para analizar los patrones de violencia en el Noreste patagónico durante el Holoceno tardío.   Abstract   The interpretation of conflict in past societies is an ambiguous process that can either underestimate or overestimate the levels of violence. The aim of this paper is to present methodology applied to the study of interpersonal violence patterns in hunter-gatherers groups from Northeastern Patagonia during the late Holocene (4000-350 years BP. While the main explored line of evidence was the bioarchaeological one, independent and complementary lines were taken into account (i.e. types of

U-Th and 10Be constraints on sediment recycling in proglacial settings, Lago Buenos Aires, Patagonia

Science.gov (United States)

Cogez, Antoine; Herman, Frédéric; Pelt, Éric; Reuschlé, Thierry; Morvan, Gilles; Darvill, Christopher M.; Norton, Kevin P.; Christl, Marcus; Märki, Lena; Chabaux, François

2018-03-01

The estimation of sediment transfer times remains a challenge to our understanding of sediment budgets and the relationships between erosion and climate. Uranium (U) and thorium (Th) isotope disequilibria offer a means of more robustly constraining sediment transfer times. Here, we present new uranium and thorium disequilibrium data for a series of nested moraines around Lago Buenos Aires in Argentine Patagonia. The glacial chronology for the area is constrained using in situ cosmogenic 10Be analysis of glacial outwash. Sediment transfer times within the periglacial domain were estimated by comparing the deposition ages of moraines to the theoretical age of sediment production, i.e., the comminution age inferred from U disequilibrium data and recoil loss factor estimates. Our data show first that the classical comminution age approach must include weathering processes accounted for by measuring Th disequilibrium. Second, our combined data suggest that the pre-deposition history of the moraine sediments is not negligible, as evidenced by the large disequilibrium of the youngest moraines despite the equilibrium of the corresponding glacial flour. Monte Carlo simulations suggest that weathering was more intense before the deposition of the moraines and that the transfer time of the fine sediments to the moraines was on the order of 100-200 kyr. Long transfer times could result from a combination of long sediment residence times in the proglacial lake (recurrence time of a glacial cycle) and the remobilization of sediments from moraines deposited during previous glacial cycles. 10Be data suggest that some glacial cycles are absent from the preserved moraine record (seemingly every second cycle), supporting a model of reworking moraines and/or fluctuations in the extent of glacial advances. The chronological pattern is consistent with the U-Th disequilibrium data and the 100-200 kyr transfer time. This long transfer time raises the question of the proportion of freshly

U–Th and 10Be constraints on sediment recycling in proglacial settings, Lago Buenos Aires, Patagonia

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A. Cogez

2018-03-01

Full Text Available The estimation of sediment transfer times remains a challenge to our understanding of sediment budgets and the relationships between erosion and climate. Uranium (U and thorium (Th isotope disequilibria offer a means of more robustly constraining sediment transfer times. Here, we present new uranium and thorium disequilibrium data for a series of nested moraines around Lago Buenos Aires in Argentine Patagonia. The glacial chronology for the area is constrained using in situ cosmogenic 10Be analysis of glacial outwash. Sediment transfer times within the periglacial domain were estimated by comparing the deposition ages of moraines to the theoretical age of sediment production, i.e., the comminution age inferred from U disequilibrium data and recoil loss factor estimates. Our data show first that the classical comminution age approach must include weathering processes accounted for by measuring Th disequilibrium. Second, our combined data suggest that the pre-deposition history of the moraine sediments is not negligible, as evidenced by the large disequilibrium of the youngest moraines despite the equilibrium of the corresponding glacial flour. Monte Carlo simulations suggest that weathering was more intense before the deposition of the moraines and that the transfer time of the fine sediments to the moraines was on the order of 100–200 kyr. Long transfer times could result from a combination of long sediment residence times in the proglacial lake (recurrence time of a glacial cycle and the remobilization of sediments from moraines deposited during previous glacial cycles. 10Be data suggest that some glacial cycles are absent from the preserved moraine record (seemingly every second cycle, supporting a model of reworking moraines and/or fluctuations in the extent of glacial advances. The chronological pattern is consistent with the U–Th disequilibrium data and the 100–200 kyr transfer time. This long transfer time raises the

ON THE UNDERSTANDING OF AEOLIAN SEQUENCE STRATIGRAPHY: AN EXAMPLE FROM MIOCENE-PLIOCENE DEPOSITS IN PATAGONIA, ARGENTINA

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CARLOS ZAVALA

2001-07-01

Full Text Available Upper Tertiary aeolian strata (Río Negro Formation outcrop in extensive sea cliffs at the Northeast of Patagonia. These outcrops show deposits corresponding to a complete suite of aeolian and aeolian related sub-environments, and also provide excellent exposures to analyse the sedimentology and internal architecture from a sequence stratigraphic point of view. Field studies, supplemented withline-drawings of oblique photographs, allowed the recognition of seven aeolian depositional sequences within the succession, each one bounded by regional super surfaces (or deflation surfaces. Internally these aeolian sequences display a cyclic recurrence in facies, that yields a tentative genetic model for their evolution. As documented from field examples, each basic aeolian depositional sequence was deposited during a single aggradational period, and is bounded by unconformities related to degradational periods. Degradational periods are regional deflationary events, that resulted in deep-scoured to flat surfaces, characterised by erosion / non deposition in which the only recognised accumulation is isolated and large angular blocks of fine-grained aggregates, interpreted as residual remnants of deposits of the previous sequence. Aggradational periods are characterised by a near- continuous accumulations responsible for the sequence building. Differences in the aeolian sediment budget to the area and the rising rate of water table control the related facies types, and allow to discriminateearly and late aggradational sub-periods. Early aggradational sub-periods form under conditions of relatively fast rising water tables associated with moderate aeolian sediment budget, thus resulting in the development of extended wet interduneslaterally associated with aeolian dunes and dry interdunes. During late aggradational sub-periods, the depositional surface outdistanced the water table, and aeolian dunes and dry interdunes tend to predominate. This sub

Traditional Mapuche ecological knowledge in Patagonia, Argentina: fishes and other living beings inhabiting continental waters, as a reflection of processes of change.

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Aigo, Juana; Ladio, Ana

2016-12-07

Understanding how people interpret environmental change and develop practices in response to such change is essential to comprehend human resource use. In the cosmology of the American indigenous peoples, as among the Mapuche people, freshwater systems are considered a living entity, where animals have an enormous role to play in the universe of meaning. However, human adaptive responses to freshwater system dynamics are scarcely examined. In this work a survey is carried out in three Mapuche communities of Argentine Patagonia to assess their traditional knowledge of the fishes and other non-human living beings that inhabit lakes and rivers. Both material and symbolic aspects are included, as are the differences in knowledge and use of the fishes between past and present times. Our methods were based on a quali-quantitative fieldwork approach. In-depth interviews were carried out with 36 individuals from three rural Mapuche populations in Neuquén province (Patagonia, Argentina). Free listing was used for inquiring about fish knowledge and use. Fishes were identified scientifically and ethnotaxonomically. In-depth analysis of the discourses was conducted, documenting the recognition, perception, and cultural significance of fluvial environments and their inhabitants. Quantitative survey results were analyzed with categorical statistical methods. The body of knowledge of the communities studied reflects the socio-environmental changes experienced by Patagonian freshwater bodies. According to local perception, non-human beings live in these water bodies, guarding the environment, and they should not be disturbed. At present, five different fish species are identified, three of which are exotic, having been introduced at the beginning of the 20th century by the white man. These exotic trout (Oncorhynchus mykiss and Salvelinus fontinalis) are considered ill omens, indicators of the white man's presence, and therefore their appearance presages negative events for the

Asimetría en el postcráneo de poblaciones humanas prehispánicas de Pampa y Patagonia

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Béguelin, Marien

2007-01-01

Full Text Available En este trabajo se evaluó el patrón de asimetría bilateral de muestras esqueletales de poblaciones cazadoras-recolectoras de Pampa y Patagonia (n=161 en el marco de una investigación centrada en la variación geográfica de la morfología postcraneal. Se analizaron tanto la presencia como el grado de asimetría observado en los huesos largos de los miembros superiores e inferiores (húmero, radio, fémur, tibia. Se examinó también el dimorfismo sexual y la variación interpoblacional. Los análisis se basaron en los porcentajes direccional y absoluto de asimetría. El primero de ellos considera tanto la magnitud de la asimetría como la lateralidad en tanto el segundo se concentra en la magnitud. Se encontró un patrón general de asimetría en todas las muestras, siendo más marcado en los miembros superiores que en los inferiores, y hacia el lado derecho. Los miembros inferiores evidencian una asimetría muy leve, y el fémur mostró una tendencia hacia la izquierda en todas sus dimensiones (fenómeno conocido como asimetría cruzada. Las asimetrías de longitud son mucho menos pronunciadas que las de diámetros de diáfisis. En todas las muestras los grupos masculinos presentan un grado mayor de asimetría que los femeninos. Se discutirán alternativas en torno a la influencia de distintos factores, a saber sexo, tipo de medida (longitud o diámetro y diferencias interpoblacionales sobre el tipo y grado de asimetría.

Silver contamination on abiotic and biotic compartments of Nahuel Huapi National Park lakes, Patagonia, Argentina

International Nuclear Information System (INIS)

Ribeiro Guevara, Sergio; Arribere, Maria; Bubach, Debora; Vigliano, Pablo; Rizzo, Andrea; Alonso, Marcelo; Sanchez, Ricardo

2005-01-01

The Ag contents of abiotic and biotic compartments of different lakes of Nahuel Huapi National Park, Patagonia, Argentina were analyzed. The water bodies studied were lakes Nahuel Huapi, Moreno, Escondido, Espejo Chico and Traful, the latter chosen as a reference lake. The Ag concentration profiles of short sediment cores, dated by 210 Pb and 137 Cs techniques, were analyzed, as well as suspended load collected from three sites of lake Nahuel Huapi. The biota studied were the native mussel Diplodon chilensis (digestive gland and total soft tissues pooled samples) and five species of fish, two native and three introduced (liver and muscle pooled samples). Ag contents were determined by Instrumental Neutron Activation Analysis (INAA). The upper layers of the sediment cores sampled in lake Nahuel Huapi were enriched in Ag contents compared to deep layers in accumulation periods corresponding to the second half of the 20th century, but this enrichment was neither observed in the reference lake Traful, nor in lakes Espejo Chico and Escondido. Ag was enriched over background level (0.1 μg g -1 ) also in suspended load collected in lake Nahuel Huapi. Ag fluxes to sediments were computed for suspended load and enriched sediment core layers. Highest Ag fluxes, from 350 to 470 μg m -2 year -1 , were measured in Nahuel Huapi near the site where the liquid effluents of the Bariloche city sewage treatment plant are released to the lake. The spatial distribution of the other Ag fluxes suggests that this is the main source of Ag to lake Nahuel Huapi and lateral transport occurs within the water body. Ag concentrations on biota samples were consistent with these conclusions. Mussels collected in lake Nahuel Huapi showed higher Ag concentrations than in the other lakes, especially when compared to lake Traful. Ag contents in mussels were strongly associated with sediment intake, but enriched probably due to sediment grain size sorting during the intake processes. Evidence of food

U-Pb zircon constraints on the age of the Cretaceous Mata Amarilla Formation, Southern Patagonia, Argentina: Its relationship with the evolution of the Austral Basin

International Nuclear Information System (INIS)

Varela, Augusto N; Poire, Daniel G; Martin, Thomas; Gerdes, Axel; Goin, Francisco J; Gelfo, Javier N; Hoffmann, Simone

2012-01-01

Despite the abundant fossil content of the Mata Amarilla Formation (Southern Patagonia, Santa Cruz Province, Argentina), its age has always generated a considerable number of questions and debates. The chronological data provided by invertebrates, dinosaurs, fish, turtles, plesiosaurs and fossil flora are contradictory. In this work, twenty U-Pb spot analyses by laser ablation were carried out on the outer parts of the zoned zircon crystals from a tuff layer of the middle section of the Mata Amarilla Formation, yielding a U-Pb concordia age of 96.23±0.71 Ma, which corresponds to the middle Cenomanian. The deposition of the lower section of the Mata Amarilla Formation marks the onset of the foreland stage of the Austral Basin (also known as Magallanes Basin); this transition is characterized by the west-east shift of the depositional systems, which is consistent with the progradation of the Cretaceous fold-and-thrust belt. Thus, the onset of the foreland stage could have occurred between the upper Albian and lower Cenomanian, as the underlying Piedra Clavada Formation is lower Albian in age. On comparing the data obtained with information from the Ultima Esperanza Province in Chile, it can be suggested that the initiation of the closure of the Rocas Verdes Marginal Basin occurred simultaneously

Sequence stratigraphic analysis of Cenomanian greenhouse palaeosols: A case study from southern Patagonia, Argentina

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Varela, Augusto N.; Veiga, Gonzalo D.; Poiré, Daniel G.

2012-10-01

The aim of this contribution is to analyse extrinsic (i.e., tectonics, climate and eustasy) and intrinsic (i.e., palaeotopography, palaeodrainage and relative sedimentation rates) factors that controlled palaeosol development in the Cenomanian Mata Amarilla Formation (Austral foreland basin, southwestern Patagonia, Argentina). Detailed sedimentological logs, facies analysis, pedofeatures and palaeosol horizon identification led to the definition of six pedotypes, which represent Histosols, acid sulphate Histosols, Vertisols, hydromorphic Vertisols, Inceptisols and vertic Alfisols. Small- and large-scale changes in palaeosol development were recognised throughout the units. Small-scale or high-frequency variations, identified within the middle section are represented by the lateral and vertical superimposition of Inceptisols, Vertisols and hydromorphic Vertisols. Lateral changes are interpreted as the result of intrinsic factors to the depositional systems, such as the relative position within the floodplain and the distance from the main channels, that condition the nature of parent material, the sedimentation rate and eventually the palaeotopographic position. Vertical stacking of different soil types is linked to avulsion processes and the relatively abrupt change in the distance to main channels as the system aggraded. The large-scale or low-frequency vertical variations in palaeosol type occurring in the Mata Amarilla Formation are related to long-term changes in depositional environments. The lower and upper sections of the studied logs are characterised by Histosols and acid sulphate Histosols, and few hydromorphic Vertisols associated with low-gradient coastal environments (i.e., lagoons, estuaries and distal fluvial systems). At the lower boundary of the middle section, a thick palaeosol succession composed of vertic Alfisols occurs. The rest of the middle section is characterised by Vertisols, hydromorphic Vertisols and Inceptisols occurring on distal and

Origin and evolution of the Laguna Potrok Aike maar (Southern Patagonia, Argentina) as revealed by seismic data

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Gebhardt, C.; de Batist, M. A.; Niessen, F.; Anselmetti, F.; Ariztegui, D.; Haberzettl, T.; Ohlendorf, C.; Zolitschka, B.

2009-12-01

Seismic reflection and refraction data provide insights into the sedimentary infill and the underlying volcanic structure of Laguna Potrok Aike, a maar lake situated in the Pali Aike Volcanic Field, Southern Patagonia. The lake has a diameter of ~3.5 km, a maximum water depth of ~100 m and a presumed age of ~770 ka. Its sedimentary regime is influenced by climatic and hydrologic conditions related to the Antarctic Circumpolar Current, the Southern Hemispheric Westerlies and sporadic outbreaks of Antarctic polar air masses. Multiproxy environmental reconstructions of the last 16 ka document that this terminal lake is highly sensitive to climate change. Laguna Potrok Aike has recently become a major focus of the International Continental Scientific Drilling Program and was drilled down to 100 m below lake floor in late 2008 within the PASADO project. The sediments are likely to contain a continental record spanning the last ca. 80 kyrs unique in the South American realm. Seismic reflection data show relatively undisturbed, stratified lacustrine sediments at least in the upper ~100 m of the sedimentary infill but are obscured possibly by gas and/or coarser material in larger areas. A model calculated from seismic refraction data reveals a funnel-shaped structure embedded in the sandstone rocks of the surrounding Santa Cruz Formation. This funnel structure is filled by lacustrine sediments of up to 370 m in thickness. These can be separated into two distinct subunits with low acoustic velocities of 1500-1800 m s-1 in the upper subunit pointing at unconsolidated lacustrine muds, and enhanced velocities of 2000-2350 m s-1 in the lower subunit. Below these lacustrine sediments, a unit of probably volcanoclastic origin is observed (>2400 m s-1). This sedimentary succession is well comparable to other well-studied sequences (e.g. Messel and Baruth maars, Germany), confirming phreatomagmatic maar explosions as the origin of Laguna Potrok Aike.

Centralized vs. de-centralized multinationals and taxes

OpenAIRE

Nielsen, Søren Bo; Raimondos-Møller, Pascalis; Schjelderup, Guttorm

2005-01-01

The paper examines how country tax differences affect a multinational enterprise's choice to centralize or de-centralize its decision structure. Within a simple model that emphasizes the multiple conflicting roles of transfer prices in MNEs – here, as a strategic pre-commitment device and a tax manipulation instrument –, we show that (de-)centralized decisions are more profitable when tax differentials are (small) large. Keywords: Centralized vs. de-centralized decisions, taxes, MNEs. ...

Petrological constraints on the recycling of mafic crystal mushes, magma ascent and intrusion of braided sills in the Torres del Paine mafic complex (Patagonia)

Science.gov (United States)

Leuthold, Julien; Müntener, Othmar; Baumgartner, Lukas; Putlitz, Benita

2014-05-01

Cumulate and crystal mush disruption and reactivation are difficult to recognise in coarse grained shallow plutonic rocks. Mafic minerals included in hornblende and zoned plagioclase provide snapshots of early crystallization and cumulate formation, but are difficult to interpret in terms of the dynamics of magma ascent and possible links between silicic and mafic rock emplacement. We will present the field relations, the microtextures and the mineral chemistry of the Miocene mafic sill complex of the Torres del Paine intrusive complex (Patagonia, Chile) and its sub-vertical feeder-zone. The mafic sill complex was built up by a succession of braided sills of shoshonitic and high-K calc-alkaline porphyritic hornblende-gabbro and fine grained monzodioritic sills. The mafic units were over-accreted over 41±11 ka, underplating the overlying granite. Local diapiric structures and felsic magma accumulation between sills indicate limited separation of intercumulus liquid from the mafic sills. Anhedral hornblende cores, with olivine + clinopyroxene ± plagioclase ± apatite inclusions, crystallized at temperatures >900°C and pressures of ~300 to ~500 MPa. The corresponding rims and monzodiorite matrix crystallized at 950°C) from the middle crust reservoir to the emplacement level. We show that hornblende-plagioclase thermobarometry is a useful monitor for the determination of segregation conditions of granitic magmas from gabbroic crystal mushes, and for monitoring the evolution of shallow crustal magmatic crystallization, decompression and cooling.

Geochemical evidence of past earthquakes in sediments of the Reloncaví fjord (Chilean Patagonia) during the last ˜ 1000 years

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Rebolledo, Lorena; Lange, Carina; Muñoz, Práxedes; Salamanca, Marco

2014-05-01

The Chilean fjords are excellent archives of paleoearthquakes, tsunamis and landslides (St-Onge et al., 2012 in Sedimentary Geology 243-244: 89-107). Here we report on new sedimentological and geochemical evidence of past earthquakes in sediments of the Reloncavi fjord, Northern Patagonia (41° S, 72° W), during the last ~1000 years. We recovered four sediment cores from the Reloncaví fjord (RH-5B, RH-5C, RH-6B, RH7B, water depth range = 90-260 m; core length range = 45-75 cm). Age models were based on 210Pb, AMS-14C and the first appearance of the diatom Rhizosolenia setigera cf. pungens in the fossil record as statigraphic marker. The cores span the last ~122 to 800 years of sedimentation with sedimentation rates ranging between 0.1 and 0.24 cm yr-1. The cores revealed evidence of turbidites associated with the historical earthquakes of 1960, 1837, 1737 and 1575 AD, and an earlier period for which there is no historical information, 1200-1400 AD. The turbidites exhibit a grading-up pattern with sand layers, and are characterized by a decrease in organic carbon and biogenic opal, an increase in the C/N molar ratio, negative values of δ13Corg(average -27),and an increase in the relative abundance of Paralia sulcata, a diatom associated with sandy environments, being the turbite layers mainly freshwater in origen. We suggest that these turbidite layers were triggered by past earthquakes that produced movement of land from the cliff areas that surround the Reloncaví fjord. Funding: Project FONDECYT # 11110103 and COPAS Sur-Austral project PFB-31.

Quaternary base-level drops and trigger mechanisms in a closed basin: Geomorphic and sedimentological studies of the Gastre Basin, Argentina

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Bilmes, Andrés; Veiga, Gonzalo D.; Ariztegui, Daniel; Castelltort, Sébastien; D'Elia, Leandro; Franzese, Juan R.

2017-04-01

Evaluating the role of tectonics and climate as possible triggering mechanisms of landscape reconfigurations is essential for paleoenvironmental and paleoclimatic reconstructions. In this study an exceptional receptive closed Quaternary system of Patagonia (the Gastre Basin) is described, and examined in order to analyze factors triggering base-level drops. Based on a geomorphological approach, which includes new tectonic geomorphology investigations combined with sedimentological and stratigraphic analysis, three large-scale geomorphological systems were identified, described and linked to two major lake-level highstands preserved in the basin. The results indicate magnitudes of base-level drops that are several orders of magnitude greater than present-day water-level fluctuations, suggesting a triggering mechanism not observed in recent times. Direct observations indicating the occurrence of Quaternary faults were not recorded in the region. In addition, morphometric analyses that included mountain front sinuosity, valley width-height ratio, and fan apex position dismiss tectonic fault activity in the Gastre Basin during the middle Pleistocene-Holocene. Therefore, we suggest here that upper Pleistocene climate changes may have been the main triggering mechanism of base-level falls in the Gastre Basin as it is observed in other closed basins of central Patagonia (i.e., Carri Laufquen Basin).

Prioridades de conservación aplicando información filogenética y endemicidad: un ejemplo basado en Carabidae (Coleoptera de América del Sur austral Conservation priorities using phylogenetic information and endemicity: an example based on Carabid beetles from Southern South America

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Sergio Roig-Juñent

2004-12-01

Full Text Available Sobre la base de la información distribucional de las especies de Carabidae (Coleoptera de América del Sur austral, se reconocieron 17 áreas de endemismo. Para cada una de ellas se estimó la diversidad gamma, el porcentaje de endemismo, el valor filogenético y la complementariedad, exceptuando Juan Fernández del cual no se pudo obtener ningún valor filogenético. El cálculo del valor filogenético se realizó a través del uso de cuatro índices, el valor filogenético sin ninguna modificación (W, considerando la endemicidad (We, y sus respectivas estandarizaciones (Ws y Wes. Los resultados muestran que la estandarización del valor filogenético (Ws produce un sesgo cuando los cladogramas difieren en tamaño y que el complemento entre áreas es una herramienta secundaria de gran utilidad. Sin embargo, los resultados muestran que para determinar la importancia de las áreas, el complemento debe ser usado en conjunto con la diversidad específica y la endemicidad. Las comparaciones de los resultados obtenidos usando W, We y análisis de complementariedad estrictos y modificados muestran que el valor filogenético que admite endemicidad (We puede ser aplicado como único valor para determinar la importancia de cada área. Aplicando We, las seis primeras áreas seleccionadas acumulan el 72 % del valor filogenético y el 74 % de la diversidad gamma de los carábidos de América del Sur austral, mientras que ninguno de los otros parámetros usados acumula el 70 % de las especies antes de sumar la séptima área. Las seis áreas seleccionadas son la Selva valdiviana, las Sierras pampeanas, Coquimbo, Patagonia occidental, Chile central y La Araucanía. Es de hacer notar que las Sierras pampeanas y la Patagonia occidental son ambientes de pastizales, Coquimbo y Chile central son ambientes áridos y semiáridos, y solo la Selva valdiviana y Araucanía son típicos bosques australesBased on information of the Southern South American carabid

U-Pb zircon constraints on the age of the Cretaceous Mata Amarilla Formation, Southern Patagonia, Argentina: its relationship with the evolution of the Austral Basin Edades U-Pb en circones de la Formación Mata Amarilla (Cretácico, Patagonia Austral, Argentina: su relación con la evoluci��n de la Cuenca Austral

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Augusto N Varela

2012-09-01

Full Text Available Despite the abundant fossil content of the Mata Amarilla Formation (Southern Patagonia, Santa Cruz Province, Argentina, its age has always generated a considerable number of questions and debates. The chronological data provided by invertebrates, dinosaurs, fish, turtles, plesiosaurs and fossil flora are contradictory. In this work, twenty U-Pb spot analyses by laser ablation were carried out on the outer parts of the zoned zircon crystals from a tuff layer of the middle section of the Mata Amarilla Formation, yielding a U-Pb concordia age of 96.23±0.71 Ma, which corresponds to the middle Cenomanian. The deposition of the lower section of the Mata Amarilla Formation marks the onset of the foreland stage of the Austral Basin (also known as Magallanes Basin; this transition is characterized by the west-east shift of the depositional systems, which is consistent with the progradation of the Cretaceous fold-and-thrust belt. Thus, the onset of the foreland stage could have occurred between the upper Albian and lower Cenomanian, as the underlying Piedra Clavada Formation is lower Albian in age. On comparing the data obtained with information from the Última Esperanza Province in Chile, it can be suggested that the initiation of the closure of the Rocas Verdes Marginal Basin occurred simultaneously.A pesar del abundante contenido fosilífero de la Formación Mata Amarilla (Patagonia Austral, Provincia de Santa Cruz, Argentina, siempre se generaron abundantes dudas y debates acerca de cuál es la edad de esta formación. Los datos cronológicos aportados por los invertebrados, los dinosaurios, peces, tortugas, plesiosaurios y flora fósil son dispares. En el presente trabajo se obtuvo una edad U-Pb concordia por la metodología de ablación láser aplicada a 20 puntos de la parte externa de circones zonados provenientes de un nivel tobáceo hallado en la sección media de la Formación Mata Amarilla, lo cual arrojó una edad de 96,23±0,71 Ma, que

Silver contamination on abiotic and biotic compartments of Nahuel Huapi National Park lakes, Patagonia, Argentina

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Ribeiro Guevara, Sergio; Arribere, Maria; Bubach, Debora; Vigliano, Pablo; Rizzo, Andrea; Alonso, Marcelo; Sanchez, Ricardo

2005-01-05

The Ag contents of abiotic and biotic compartments of different lakes of Nahuel Huapi National Park, Patagonia, Argentina were analyzed. The water bodies studied were lakes Nahuel Huapi, Moreno, Escondido, Espejo Chico and Traful, the latter chosen as a reference lake. The Ag concentration profiles of short sediment cores, dated by {sup 210}Pb and {sup 137}Cs techniques, were analyzed, as well as suspended load collected from three sites of lake Nahuel Huapi. The biota studied were the native mussel Diplodon chilensis (digestive gland and total soft tissues pooled samples) and five species of fish, two native and three introduced (liver and muscle pooled samples). Ag contents were determined by Instrumental Neutron Activation Analysis (INAA). The upper layers of the sediment cores sampled in lake Nahuel Huapi were enriched in Ag contents compared to deep layers in accumulation periods corresponding to the second half of the 20th century, but this enrichment was neither observed in the reference lake Traful, nor in lakes Espejo Chico and Escondido. Ag was enriched over background level (0.1 {mu}g g{sup -1}) also in suspended load collected in lake Nahuel Huapi. Ag fluxes to sediments were computed for suspended load and enriched sediment core layers. Highest Ag fluxes, from 350 to 470 {mu}g m{sup -2} year{sup -1}, were measured in Nahuel Huapi near the site where the liquid effluents of the Bariloche city sewage treatment plant are released to the lake. The spatial distribution of the other Ag fluxes suggests that this is the main source of Ag to lake Nahuel Huapi and lateral transport occurs within the water body. Ag concentrations on biota samples were consistent with these conclusions. Mussels collected in lake Nahuel Huapi showed higher Ag concentrations than in the other lakes, especially when compared to lake Traful. Ag contents in mussels were strongly associated with sediment intake, but enriched probably due to sediment grain size sorting during the intake

Le site paléo-indien de Piedra Museo (Patagonie). Sa contribution au débat sur le premier peuplement du continent américainThe palaeo-indian site of Piedra Museo (Patagonia). Its contribution to the debate on the peopling of the Americas.

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Ramirez Rozzi, Fernando V.; d'Errico, Francesco; Zarate, Marcelo

2000-08-01

The Piedra Museo site (Santa Cruz, Argentina), excavated over the past nine years has yielded a rich archaeological record, which contributes to the discussion on the first peopling of the Americas. We present here a new study of the site, based on an analysis of the stratigraphy, spatial distribution of archaeological remains, bone taphonomy, and discussion of new AMS- 14C dates. We conclude that remains of extinct species with cut-marks from the lower levels are contemporaneous of stone tools and cores from the same levels. This demonstrates that humans were present in the southern part of Patagonia around 10 300 and 11 100 years BP and suggests that hunting of large mammals was a part of their subsistence strategies.

Plankton dynamics and photosynthesis responses in a eutrophic lake in Patagonia (Argentina: influence of grazer abundance and UVR Dinámica del plancton y respuestas fotosintéticas en una laguna eutrófica de Patagonia (Argentina: influencia de la abundancia de herbívoros y RUV

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Rodrigo J Gonçalves

2011-01-01

Full Text Available A natural plankton population from the eutrophic lake Cacique Chiquichano, in the Argentine Patagonia, was monitored for one year to evaluate changes in photosynthetic parameters as a result of exposure to ultraviolet radiation (UVR, 280-400 nm, grazer abundance, and the taxonomic composition of the phytoplankton community. Both physical (temperature, solar radiation and biological (grazers, taxonomic composition, photosynthetic parameters variables fluctuated throughout the study. Crustacean zooplankton showed alternating dominance between cladocerans (Daphnia spinulata and copepods (Metacyclops mendocinus. The phytoplankton community underwent concomitant changes throughout the year, with cyanobacteria and diatoms alternately dominating. In addition, although copepod abundance was not significantly related to changes in phytoplankton, the presence of D. spinulata was significant during periods of more transparent water; these periods were dominated by diatoms. On the other hand, cyanobacteria dominated the phytoplankton assemblage when the penetration of solar radiation into the water column was lower. Photosynthetic inhibition due to UVR decreased during the diatom-dominated periods. In contrast, inhibition increased along with the proportion of cyanobacteria, likely as a result of acclimation to low irradiance during the lake's phase of lower transparency. Moreover, the presence of D. spinulata was associated with the increased penetration of solar radiation into the water column, resulting in an indirect increment in the inhibition of cyanobacteria photosynthesis. The results suggest that both solar radiation and grazing abundance strongly influence the dynamics and photosynthetic activity of the phytoplankton in Lake Cacique Chiquichano.Se estudió a lo largo del año una comunidad planctónica natural de la laguna eutrófica Cacique Chiquichano de Patagonia-Argentina, para evaluar los cambios en parámetros fotosintéticos como resultados

Current use of wild plants with edible underground storage organs in a rural population of Patagonia: between tradition and change.

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Ochoa, Juan José; Ladio, Ana Haydee

2015-09-25

Edible plants with underground storage organs (USOs) are neglected resources. We studied the local ecological knowledge edible plants with (USOs) in rural populations of North-Patagonia in order to establish how people are utilizing these plants. Some aspect of corpus-praxis-cosmos complex associated to the local ecological knowledge was documented and discussed. In addition, variation in this ecological knowledge due to age, gender, family structure, ethnic self-determination was also evaluated. Semi-structured interviews were conducted with 51 inhabitants in order to study the relationship between the current use of plants with USOs and the age, sex, family group composition and ethnic self-identification of interviewees. In addition, the Cultural Importance Index for each species was calculated. The current richness of known species in these populations is a total of 9 plants. Plants with USOs tend to be used more frequently as the age of the interviewee increases. Women and men showed no differences in the average richness of species cited. The interviewees who share their homes with other generations use these plants more frequently than those who live alone. Our results indicate that the interviewees who identified themselves as belonging to the Mapuche people use these plants more frequently. For the Mapuche people, wild plants have constituted material and symbolic resources of great importance in their historical subsistence. In addition, they are currently being redefined as elements which present a connection with ancestral practices, produce a strong relationship with the 'land', and become markers which identify the 'natural' (historical) ways of their people; these are key elements in the current political processes of identity revaluation. This research is valuable to stimulate cultural revival and health promotion programs in the communities with their own local, cultural food.

Las sociedades anónimas cruzan los Andes: los inversores chilenos en Neuquén al comenzar el siglo XX

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Graciela Blanco

2012-08-01

Full Text Available El territorio de Neuquén, en el norte de la Patagonia, atrajo la mirada de diversos inversores privados a partir del avance militar que realizó el Estado nacional sobre los grupos indígenas y de la conquista de las tierras del sur argentino; tierras que fueron ofrecidas a particulares en propiedad o arrendamiento en condiciones muy beneficiosas. Este trabajo analiza la conformación en Chile, en los primeros años del siglo XX, de sociedades anónimas que explicitaban como objetivo central la intención de comprar tierras a ambos lados de la Cordillera de los Andes para la explotación agroganadera y la comercialización, y estudia específicamente el origen, itinerario y organización productiva de una de esas sociedades en Neuquén.Neuquen territory, in the north of the Patagonia, attracted the look of diverse investors after from the military advance that realized the national State on the indigenous groups and of the conquest of the lands of the Argentine's south, lands that were offered to individuals in property or lease in very beneficial conditions. This work analyzes the conformation in Chile, in the first years of the 20th century, of joint-stock companies that stated explicitly as central aim the intention of buying lands on both sides of the Mountain chain of the Andes for the agricultural and livestock exploitation and the commercialization, and there studies specifically the origin, itinerary and productive organization of one of these companies in Neuquen.

Changing fluvial styles in volcaniclastic successions: A cretaceous example from the Cerro Barcino Formation, Patagonia

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Umazano, A. Martín; Krause, J. Marcelo; Bellosi, Eduardo S.; Perez, Mariano; Visconti, Graciela; Melchor, Ricardo N.

2017-08-01

The Cretaceous Puesto La Paloma (PLPM) and Cerro Castaño (CCM) members (Cerro Barcino Formation, Chubut Group) are pyroclastic-rich, alluvial successions deposited in the Somuncurá-Cañadón Asfalto Basin during sag and endorheic conditions. The PLPM comprises sheet-like tuffaceous sandstone strata, whereas the overlying CCM includes sheet-to ribbon-channel sandstone bodies intercalated within tuffaceous and fine-grained sediments. In this context, the goals of this contribution were: i) to make a detailed documentation of the contrasting sedimentary palaeonvironments; and ii) to infer the allocyclic controls that governed the sedimentation of both units. The study area is located in the western sector of the basin, where six localities, which were studied. Six facies associations were defined including ash-falls, sheet-floods, shallow lakes, aeolian, fluvial channel-belts, and reworked debris-flows. We defined four stratigraphic intervals for the studied sections, denominated 1 to 4 in chronological order of deposition, which increase their thicknesses toward the Puesto Mesa-Cerro León site. The interval 1 (18-42 m thick) corresponds to the PLPM and includes numerous pedogenized sheet-flood deposits, carbonate-rich lacustrine, aeolian sandy facies, and ash-fall beds. The interval 1 is interpreted as an ephemeral and unconfined alluvial system that interacted with aeolian dunes and dry interdune zones. The interval 2 (20-47 m thick) represents the lower part of the CCM. It shows an alternation of fluvial channel-belt deposits and vegetated floodplain facies with sediments originated from sheet-floods, lakes, and few ash-falls and debris-flows. The mean palaeoflow was toward E-SE, except in the northernmost locality where the drainage was towards SW. Proportion of channel-belt bodies ranges from 10 to 36%, reaching higher values in the northern part of the study area, where they are also thicker. The interval 2 represents a permanent, meandering or locally low

Harnessing maize biodiversity

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Maize is a remarkably diverse species, adapted to a wide range of climatic conditions and farming practices. The latitudinal range of maize is immense, ranging from 54°N in Alberta, Canada, to 45°S in the province of Chubut, Argentina. In terms of altitude, maize is cultivated from sea level to 4000...

A Product Line Analysis for Eco-Designed Fashion Products: Evidence from an Outdoor Sportswear Brand

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Luo Wang

2017-07-01

Full Text Available With the increasing awareness of sustainability, eco-design has been an important trend in the fashion industry. Many fashion brands such as Nike, Adidas, and The North Face have developed sustainable fashion by incorporating eco-design elements. Eco-design is an important part of sustainable supply chains. In this paper, we conducted a product line analysis of eco-designed products from a famous outdoor sportswear brand, Patagonia. We collected Patagonia’s 2017 Spring Season product line data and analyzed the data through descriptive analysis, factor analysis and correlation analysis. We found that Patagonia mainly uses organic, recycled, and traceable materials in their eco-product line development. We identified that the usage of eco-materials may significantly affect the number of color choices and product weight as well as gender difference, pattern design, product fit and online reviewers’ opinions at Patagonia. We argued that Patagonia should focus on functionality more than aesthetics in eco-design. We discussed how sustainable fashion firms should manage eco-design in the supply chain.

Imprints of climate signals in a 204 year 18O tree-ring record of Nothofagus pumilio from Perito Moreno Glacier, southern Patagonia (50°S).

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Grießinger, Jussi; Langhamer, Lukas; Schneider, Christoph; Saß, Björn-Lukas; Steger, David; Skvarca, Pedro; Braun, Matthias H.; Meier, Wolfgang J.-H.; Srur, Ana M.; Hochreuther, Philipp

2018-04-01

A 204 year-long record of 18O in tree-ring cellulose of southern beech (Nothofagus pumilio) from a site near Perito Moreno Glacier (50°S) in southern Patagonia was established to assess its potential for a climate reconstruction. The annually resolved oxygen isotope chronology is built out of seven individual tree-ring 18O series with a significant mean inter-series correlation (r = 0.61) and is the first of its kind located in Southern America south of 50°S. Over a common period from 1960 to 2013 of available stationary and high-resolution gridded CRU TS v. 4.01 data, the 18O chronology exhibits a strong sensitivity towards hydroclimatic as well as temperature parameters as revealed by correlation analyses. Among these, positive correlations with maximum temperature in the first part of the summer season (CRU rONDJ = 0.51, pAmerica. The modulation of positive and negative anomalies within this series can be interlinked to changes in moisture source origin as revealed by backward trajectory modeling. Additionally, these anomalies can be directly associated to positive or negative phases of the Antarctic Oscillation Index (AAOI) and therefore the strength of the Westerlies. Aligned by the analysis on the influence of different main weather types on the 18O chronology it is shown that such time-series hold the potential to additionally capture their respective influence and change during the last centuries.

Molecular characterization of Echinococcus isolates indicates goats as reservoir for Echinococcus canadensis G6 genotype in Neuquén, Patagonia Argentina.

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Soriano, S V; Pierangeli, N B; Pianciola, L; Mazzeo, M; Lazzarini, L E; Saiz, M S; Kossman, A V; Bergagna, H F J; Chartier, K; Basualdo, J A

2010-12-01

Human cystic echinococcosis is a highly endemic zoonotic disease in the province of Neuquén, Patagonia Argentina, although a hydatid control programme has been carried out since 1970. Human infection due to Echinococcus canadensis (G6 genotype) is frequent in Neuquén. However, the reservoir for this species remains undetermined in a region where camels are absent. We investigated the fertility, viability and molecular epidemiology of hydatid cysts obtained from local goats, pigs and sheep in order to identify the possible reservoirs of E. canadensis (G6). We also analyzed isolates from infected dogs. A total of 67 isolates were identified by the DNA sequencing of the mitochondrial cytochrome c oxidase subunit 1 gene. Cysts from sheep (n=16), goats (n=23) and pigs (n=18) and adult worms from 10 infected dogs were analyzed. The fertility of the hydatid cysts was 78.6%; 90.4% and 94.4% for sheep, goats and pigs, respectively. We detected E. canadensis (G6) in 21 of 23 goat samples and in 1 dog isolate, E. canadensis (G7) in all the pig isolates, E. granulosus sensu stricto (G3) in 1 sheep and the G1 genotype in 15 sheep, 2 goats and 9 dog samples. The G1 haplotypes included the common sheep strain sequence and 2 microvariants of this sequence. E. granulosus sensu stricto (G3) is described for the first time in South America. We conclude that goats act as reservoir for E. canadensis (G6) in Neuquén, and that control strategies may have to be adapted to local molecular epidemiology to improve the control of parasite transmission. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

An 18,000 year-long eruptive record from Volcán Chaitén, northwestern Patagonia: Paleoenvironmental and hazard-assessment implications

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Alloway, Brent V.; Pearce, Nick J. G.; Moreno, Patricio I.; Villarosa, Gustavo; Jara, Ignacio; De Pol-Holz, Ricardo; Outes, Valeria

2017-07-01

The 2008 eruption of Volcán Chaitén (VCha) in northwestern Patagonia was the first explosive rhyolitic eruption to have occurred within a century and provided an unprecedented scientific opportunity to examine all facets of the eruption ranging from magma rheology/ascent rates to ash-fall effects on biota and infrastructure. Up to very recently it was thought that the latest eruption prior to the 2008 event occurred c. 9750 cal. a BP. Although a number of researchers have recognised additional eruptive products, but their stratigraphy, age, and geochemical attributes have not been systematically described and/or recorded. In this study, we provide a detailed examination of andic cover-beds and tephra-bearing lake sequences located both proximally and distally to VCha, which record a series of hitherto unknown rhyolitic eruptive products and place all previous observations firmly within a coherent stratigraphic framework. Through major- and trace-element glass shard geochemistry we are able to confidently verify eruptive source. A total of 20 discrete tephra beds are recognised, with at least 10 having widespread areal distributions and/or depositional imprints broadly comparable to, or greater than, the 2008-tephra event. This record indicates that VCha has been continuously but intermittently active as far back as the end of the Last Glacial Maximum (c. 18,000 cal a BP) with two dominant, genetically related magma types and an intermediary 'mixed' type. Before this the eruptive record has been largely obscured and/or erased by widespread Andean piedmont glaciation. However, based on the tempo of VCha activity over the last c. 18,000 years, older VCha eruptives can be anticipated to occur as well as future hazardous explosive events. The new eruptive inventory will ultimately be useful for correlating equivalent-aged sequences and refining long-term eruptive tempo as well as corresponding temporal changes in magmatic evolution.

Biotic diversity of benthic macroinvertebrates at contrasting glacier-fed systems in Patagonia Mountains: The role of environmental heterogeneity facing global warming.

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Miserendino, María Laura; Brand, Cecilia; Epele, Luis B; Di Prinzio, Cecilia Y; Omad, Guillermo H; Archangelsky, Miguel; Martínez, Oscar; Kutschker, Adriana M

2018-05-01

Patagonia is by far the largest glacierized area in South America. However, little is known about ecology, functioning and biodiversity of glacier-fed streams facing global warming. We investigated changes in environmental features and macroinvertebrate communities along a longitudinal gradient of glacier influence of two Patagonian systems that differ in glacier cover magnitude and the spatial sequence of lotic and lentic phases. Both glaciers, Torrecillas (~5.5km 2 , Torrecillas system) and Cónico (~0.44km 2 , Baggilt system), are retreating. Longitudinal distribution of benthic invertebrates partially fitted to predictions for glacierized temperate systems, with Diamesinae spp. dominating at closest sites to the Cónico, and Orthocladiinae increasing downstream, but patterns were unclear at Torrecillas. Generalized Linear Model identified chlorophyll a and conductivity as having significant effect on richness and density respectively at Torrecillas; detritus biomass and gravel influenced species richness, and boulder percentage and water temperature affected density, at Baggilt. Canonical Correspondence Analyses integrating benthic biota and environmental variables revealed that a higher environmental heterogeneity at Baggilt, related with spatial dimension (unshaded/shaded reaches, wetland reaches), local resources (detritus, bryophytes) and temperature, probably explained the unexpected high richness in benthic assemblages (67 taxa). Environmental conditions imposed by the lake outlet (proglacial) at Torrecillas resulted in a less diverse community (31 taxa). Finally our results suggest that these isolated, small glacier-fed streams typical of the Patagonian landscape appear highly vulnerable to global warming. Endemic elements could disappear at upper segments being replaced by other species common at rhithral environments, which might increase local diversity (alfa diversity) but decrease regional diversity (gamma diversity). From an ecosystem perspective

Improvement of isotope-based climate reconstructions in Patagonia through a better understanding of climate influences on isotopic fractionation in tree rings

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Lavergne, Aliénor; Daux, Valérie; Villalba, Ricardo; Pierre, Monique; Stievenard, Michel; Srur, Ana Marina

2017-02-01

Very few studies of stable isotopes exist across the Andes in South America. This study is the first presenting annually resolved chronologies of both δ18 O and δ13 C in Nothofagus pumilio and Fitzroya cupressoides trees from Northern Patagonia. Interannual variability in δ18 O and δ13 C was assessed over the period 1952-2011. Based on these chronologies, we determined the primary climatic controls on stable isotopes and tree physiological responses to changes in atmospheric CO2 concentrations (ca), temperature and humidity. Changes in specific intrinsic water use efficiency (iWUE) were inferred from variations in δ13 C whereas the effects of CO2 increase on stomatal conductance were explored using δ18 O. Over the 60-year period, iWUE increased significantly (by ca. 25%) in coincidence with the rise of ca. The two species appear to have different strategies of gas-exchange. Whereas iWUE variations were likely driven by both stomatal conductance and photosynthetic assimilation rates in F. cupressoides, they were largely related to stomatal conductance in N. pumilio. After removing the low-frequency trends related to increasing ca, significant relationships between δ13 C and summer temperatures were recorded for both species. However, δ13 C variations in F. cupressoides were more strongly influenced by summer temperatures than in N. pumilio. Our results advocate for an indirect effect of summer temperatures on stable isotope ratios, which is mostly influenced by sunlight radiation in F. cupressoides and relative humidity/soil moisture in N. pumilio. δ13 C variations in F. cupressoides were spatially correlated to a large area south of 35°S in southern South America. These promising results encourage the use of δ13 C variations in F. cupressoides for reconstructing past variations in temperature and large-scale circulation indexes such as the Southern Annular Mode (SAM) in the Southern Hemisphere.

Relative Paleointensity of the Geomagnetic Field 12-20 kyr. From Sediment Cores, Lake Moreno (Patagonia, Argentina)

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Gogorza, C. S.; Irurzun, M. A.; Chaparro, M. A.; Lirio, J. M.; Nunez, H.; Sinito, A. M.

2007-05-01

, M.A.E. Chaparro, J.M. Lirio, H. Nunez, P.G. Bercoff, A.M. Sinito. Relative paleointensity of the geomagnetic field over the last 21,000 years BP from sediment cores, Lake El Trébol (Patagonia, Argentina). Earth Planet Space. 58: 1323-1332, 2006.

Lateglacial and Holocene climatic changes in south-eastern Patagonia inferred from carbonate isotope records of Laguna Potrok Aike (Argentina)

Science.gov (United States)

Oehlerich, M.; Mayr, C.; Gussone, N.; Hahn, A.; Hölzl, S.; Lücke, A.; Ohlendorf, C.; Rummel, S.; Teichert, B. M. A.; Zolitschka, B.

2015-04-01

First results of strontium, calcium, carbon and oxygen isotope analyses of bulk carbonates from a 106 m long sediment record of Laguna Potrok Aike, located in southern Patagonia are presented. Morphological and isotopic investigations of μm-sized carbonate crystals in the sediment reveal an endogenic origin for the entire Holocene. During this time period the calcium carbonate record of Laguna Potrok Aike turned out to be most likely ikaite-derived. As ikaite precipitation in nature has only been observed in a narrow temperature window between 0 and 7 °C, the respective carbonate oxygen isotope ratios serve as a proxy of hydrological variations rather than of palaeotemperatures. We suggest that oxygen isotope ratios are sensitive to changes of the lake water balance induced by intensity variations of the Southern Hemisphere Westerlies and discuss the role of this wind belt as a driver for climate change in southern South America. In combination with other proxy records the evolution of westerly wind intensities is reconstructed. Our data suggest that weak SHW prevailed during the Lateglacial and the early Holocene, interrupted by an interval with strengthened Westerlies between 13.4 and 11.3 ka cal BP. Wind strength increased at 9.2 ka cal BP and significantly intensified until 7.0 ka cal BP. Subsequently, the wind intensity diminished and stabilised to conditions similar to present day after a period of reduced evaporation during the "Little Ice Age". Strontium isotopes (87Sr/86Sr ratio) were identified as a potential lake-level indicator and point to a lowering from overflow conditions during the Glacial (∼17 ka cal BP) to lowest lake levels around 8 ka cal BP. Thereafter the strontium isotope curve resembles the lake-level curve which is stepwise rising until the "Little Ice Age". The variability of the Ca isotope composition of the sediment reflects changes in the Ca budget of the lake, indicating higher degrees of Ca utilisation during the period with

Variability of Soil Types in Wetland Meadows in the South of the Chilean Patagonia Variabilidad de Tipos de Suelos en Las Vegas del Sur de la Patagonia Chilena

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Ladislava Filipová

2010-06-01

Full Text Available The wetland meadows and pastures (vegas of the agricultural zone of the Magallanes Region and the Chilean Patagonia are productive and intensively exploited ecosystems. However, there is scarce data about the typology and the physical and chemical properties of the soils that determine the agricultural potential of vegas sites. Sampling of the main horizons of 47 soil profiles was conducted throughout the area. The profiles were described in the field and consequently classified according to the soil typology system of the WRB (IUSS Working Group WRB, 2006. Analyses of bulk and particle densities, capillary water capacity, pH (H2O, pH (CaCl2, texture, organic material, C:N ratio, electrical conductivity, effective cation exchange capacity, N, P, Ca-Mg-K-Na, exchangeable Al,  extractable Al, sulfur SO4(2-, B, and micronutrients (Cu-Zn-Mn-Fe were carried out.  The most frequently recorded groups of soil types in the studied vegas were Histosols - peat soils (20 profiles, and Fluvisols (19. Gleysols (3, Vertisols (1, Regosols (3, Solonchaks (1 and Solonetzs (1 were detected with much less frequency. There is also considerable variability in soil properties among and within the groups of soil types. The principal differences between the Histosols and the Fluvisols are the content of organic matter (often peat, pH level (related to the absence/presence of carbonates and associated soil properties. Fluvisols are more susceptible to salinization under conditions of aridity, whereas the main threat to Histosols is artificial drainage.Las praderas húmedas (vegas de la zona de uso agropecuario de la Región de Magallanes y la Antártica Chilena son ecosistemas productivos e intensamente explotados. No obstante, los conocimientos de los factores edáficos que determinan el potencial de las vegas son escasos. En este trabajo se realizó el muestreo de los horizontes principales de 47 perfiles del suelo de distintos tipos de vegas de la zona. Los perfiles

Transboundary protected area proposals along the Southern Andes of Chile and Argentina: Status of current efforts

Science.gov (United States)

Peter Keller

2007-01-01

An evolving network of protected areas along the southern Andes of Chile and Argentina-the heart of Patagonia-are in various stages of evaluation and potential Transboundary Protected Area designations. This paper examines three such efforts. The first proposal is the North Andean-Patagonia Regional Eco-Corridor, which was the subject of a recent bilateral meeting...

Central sleep apnea

Science.gov (United States)

Sleep apnea - central; Obesity - central sleep apnea; Cheyne-Stokes - central sleep apnea; Heart failure - central sleep apnea ... Central sleep apnea results when the brain temporarily stops sending signals to the muscles that control breathing. The condition ...

Environmental conditions, early life stages distributions and larval feeding of patagonian sprat Sprattusfuegensis and common sardine Strangomerabentincki in fjords and channels of the northern Chilean patagonia

Science.gov (United States)

Contreras, Tabit; Castro, Leonardo R.; Montecinos, Sandra; Gonzalez, Humberto E.; Soto, Samuel; Muñoz, Maria I.; Palma, Sergio

2014-12-01

We assessed ontogenetic changes in distribution and feeding of the Patagonian sprat Sprattus fuegensis and common sardine Strangomera bentincki, and their association with environmental characteristics (hydrography, larval food, gelatinous zooplankton predators), and actual feeding from inshore to offshore areas of the Chilean Patagonia. During the springs of 2007 and 2008, S. bentincki egg and larvae were present north of the Taitao Peninsula (47°S) and S. fuegensis was found to the south of the peninsula. Along the inshore-offshore axis, distributions also differed: while eggs and early larval stages of S. bentincki occurred inshore and seawards, larger larvae occurred mostly seawards. The opposite was observed in S. fuegensis. However, distributions of both species followed the same rule, determined by the size of their prey: eggs and early larval stages occurred in areas of higher abundance of small prey sizes, and larger larvae coincided with the highest abundances of larger prey sizes. No relationship was detected between potential gelatinous predators and the egg and larval distributions of both fish species. Mean ingested prey sizes in both species increased as larvae grew, while maintaining the capacity to feed on small sized items. This ontogenetic feeding pattern and the distributions linked to prey seem to be beneficial in order to take advantage of short term food pulses and to overcome the strong changes in environmental conditions east to west from fjords to open waters.

A community in the wildland-urban interface

Science.gov (United States)

María Cecilia Ciampoli Halaman

2013-01-01

Communities located in the wildland-urban interface undergo a process of transformation until they can guard against fires occurring in the area. This study analyzed this process for the Estación neighborhood in the city of Esquel, Chubut Province, Argentina. The analysis was performed by comparing the level of danger diagnosed for each neighborhood home in 2004 with...

Orden monetario y bancos centrales Monetary order and Central Banks

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Aglietta Michel

1996-06-01

Full Text Available Con el enfoque evolucionista e institucionalista de la economía de las convenciones francesa, este trabajo analiza el surgimiento histórico de la banca central y la creación institucional del 'arte de la banca central'. El artículo estudia los modelos formales del orden monetario, la banca libre y la banca central, y analiza los eventos históricos que llevaron a que el Banco de Inglaterra inventara el arte de manejar los bancos centrales en conjunción con el aprendizaje colectivo e institucional que lo hizo posible. Aglietta muestra que la banca central no es una creación del Estado sino una creación institucional endógena al sistema de mercado.With the evolutionist and institutionalist focus of the economics of the French conventions, this paper analyzes the historical rise of the central bank and the institutional creation of the 'art of the central bank'. The article studies formal models of the monetary order, free banking and the central bank, and analyzes the historie events that led to the Bank of England inventing the art of managing the central banks, in conjunction with the collective and institutional learning that made it possible. Aglietta shows that the central bank is not a creation of the State, but rather aninstitutional creation endogenous to the market system.

The Regional Centrality of Vietnam’s Central Highlands

DEFF Research Database (Denmark)

Salemink, Oscar

2018-01-01

strategic value turned it into a battleground among various Vietnamese parties, France, and the United States. It was here that the outcome of the Indochina wars was determined, but at a terrible price for the local population. After the adoption of economic reforms in reunified Vietnam the Central......Vietnam’s Central Highlands—or Tây Nguyên—area is usually described as remote, backward, and primitive, but this region has played a central role in the history of the surrounding states and the wider East and Southeast Asia region. Far from isolated, the Central Highlands engaged in trade...... various rivalrous polities now known as Vietnam, Champa, Cambodia, Laos, and Thailand, the area occupied a strategic position in the wider mainland Southeast Asia region. With the emergence of a unified, neo-Confucianist Vietnamese state the region lost its centrality until the late colonial era, when its...

Bases para una interpretación tipológica de la vivienda rural introducida en la Patagonia Suroccidental desde el fenómeno de sus adaptaciones al clima

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Juan Pablo Fernández Goycoolea

2014-12-01

Full Text Available Se postula que durante ciertas etapas del desarrollo rural de la Patagonia suroccidental ocurrió un proceso de mixtura y adaptación de tradiciones culturales y constructivas diversas, que dio como resultado una arquitectura introducida pero adaptada al territorio, la que se concreta, particularmente, a través de las relaciones entre los recintos que conforman la vivienda y los que definen su vinculación con el contexto climático. Entre estos últimos, destaca la importancia de los elementos perimetrales, dado su potencial de adaptación al clima local. Se reconoce, asimismo, determinadas organizaciones espaciales que ayudaron a la constitución de una identidad arquitectónica en el contexto de estudio, y se enfatiza en los procesos adaptativos que se desarrollaron en virtud de la condición rural de las viviendas analizadas para relacionarse con el ambiente en su dimensión climática. Se sostiene, finalmente, que esta interpretación permite complementar la valorización del patrimonio arquitectónico, en función de los hábitos de uso relacionados con la condición térmica de las viviendas, antes que por la sola catalogación estética o figurativa.

Influence of precipitation, landscape and hydrogeomorphic lake features on pelagic allochthonous indicators in two connected ultraoligotrophic lakes of North Patagonia

International Nuclear Information System (INIS)

Queimaliños, Claudia; Reissig, Mariana; Diéguez, María del Carmen; Arcagni, Marina; Ribeiro Guevara, Sergio; Campbell, Linda; Soto Cárdenas, Carolina; Rapacioli, Raúl

2012-01-01

We investigated the terrestrial influence on two chained deep ultraoligotrophic lakes of North Patagonia (Argentina) through the seasonal analysis of two pelagic allochthonous indicators: i) water color, as a proxy of allochthonous dissolved organic matter in lakes; and ii) the color to chlorophyll a ratio (Color:Chla), as an indicator of the relationship between allochthonous and autochthonous carbon pools. We also evaluated the potential transfer pathways of the allochthonous dissolved organic matter into the pelagic food webs of these deep lakes, including the natural zooplankton δ 13 C in the analysis. The dynamics of the allochthonous indicators were related to the precipitation regime, water level fluctuations, and hydrogeomorphic and catchment features of lakes Moreno East and Moreno West. The water color (absorbance at 440 nm) was extremely low ( −1 ) in both lakes regardless of the season. However, precipitation and snowmelt regimes drove the increase and decrease of water color, respectively. A significant positive relationship between the zooplankton bulk δ 13 C with the water color would suggest an input of allochthonous organic carbon into the pelagic consumers. The incorporation of the dissolved allochthonous material into higher trophic levels is likely favored by the bacterivorous behavior of planktonic organisms, mixotrophic flagellates and ciliates, which dominate the pelagic food webs of these Patagonian lakes. Morphometric aspects, mainly the higher water residence time, led to lower values of allochthony in Moreno East compared to Moreno West, probably accentuated by its upper position in the lake chain. Overall, our results suggest that these allochthonous signals can bring insight into the magnitude of the interaction between terrestrial environments and lake ecosystems, even in extremely clear and ultraoligotrophic systems, such as the Andean Patagonian lakes. - Highlights: ► Pelagic allochthonous indicators were detected in two

Una vuelta a la “casa bonita”. Un bricolage interpretativo de las fuentes documentales sobre los rituales de menarquía de los pueblos originarios de la Patagonia argentina (Siglos XIX y XX

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Graciela Hernández

2015-12-01

Full Text Available El principal objetivo de este trabajo es proponer un nuevo análisis del texto del británico Georges Musters, de su descripción de una ceremonia de menarquía (a la que denominó “casa bonita” observada entre tehuelches de la Patagonia en 1869, para contextualizarla históricamente y desde una perspectiva de género.Desde la metodología cualitativa hemos armado un bricolage que se expresa en un recorrido articulado por una genealogía de fuentes documentales del siglo XIX, por testimonios producidos en trabajos antropológicos y lingüísticos en la segunda mitad del siglo XX, y por registros etnográficos de nuestros trabajos en historia oral que focalizan en  rituales para propiciar el hilado.La triangulación de fuentes de los documentos seleccionados nos lleva a pensar en la hipótesis que en las ceremonias de primera menstruación, del siglo XIX en adelante, se propiciaba el apego al hilado y tejido,  en sociedades que también  ritualizaron toda la esfera del trabajo textil.

Centralized vs. De-centralized Multinationals and Taxes

DEFF Research Database (Denmark)

Nielsen, Søren Bo; Raimondos-Møller, Pascalis; Schjelderup, Guttorm

2005-01-01

The paper examines how country tax differences affect a multinational enterprise's choice to centralize or de-centralize its decision structure. Within a simple model that emphasizes the multiple conflicting roles of transfer prices in MNEs - here, as a strategic pre-commitment device and a tax...

Tachymenis chilensis Schegel, 1837 (Reptilia: Squamata: Dipsadidae. New record and geographic distribution map

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Morando, Mariana

2012-05-01

Full Text Available We present the first vouchered record from Chubut provincein Futaleufú Department. Suburbs of Esquel city, along Ruta Nacional 259 to Trevelin on El Pinar, Roberts Farm. This is the southernmost record for the species; to our knowledge the previous southernmost registered specimen was based on collected specimens from Piltriquitrón Mountain in El Bolson, Los Lagos Department, Rio Negro Province.

Characterization of black volcanites from the Limay river basin, Patagonia, Argentina, using energy dispersive X-ray fluorescence spectrometry: an aid to infer human group mobility

International Nuclear Information System (INIS)

Palacios, O.M.

2013-01-01

The investigation of hunter-gatherers archaeological sites in the Limay river basin, Patagonia, Argentina, raised questions concerning the lithic technology. The chemical characterization of artifacts, rocks and possible sources of provenances could help to elucidate the hunter-gatherer mobility. In three archaeological sites-Rincon Chico 2 (RCh2/87; 14 C 710 ± 60 BP), Cueva Traful I (CTI; 14 C 9430 ± 230 BP) and Casa de Piedra de Ortega (CPO; 14 C 2840 ± 80 BP), tools and debitage or discarded flakes made in black volcanic rock have been found. Nearby an extensive rock outcrop of black volcanite, Paso Limay quarry (CPL), with similar characteristics was located. Samples coming from these four sites were analyzed by energy dispersive X-ray fluorescence spectrometry. This characterization allowed the geochemical classification of the lithic material and to correlate the samples with the suspected source after a previous statistical analysis. The majority of the samples were classified as dacites and rhyolites. Only samples coming from CPO site, the closest place to CPL were made exclusively with the quarry rocks. A set of five samples from RCh2/87 and two samples from CTI appear to have same chemical composition as CPL in spite of this site is placed in the opposite bank of the Limay river suggesting that hunter-gatherers could accede to the quarry, eventually. Finally, only a set of five samples coming from RCh2/87 and CTI do not group with the quarry. This fact evidences the existence of secondary sources of supply. The information of this research allowed inferring ancient human mobility patterns in the region. (author)

Trans-pacific glacial response to the Antarctic Cold Reversal in the southern mid-latitudes

Science.gov (United States)

Sagredo, Esteban A.; Kaplan, Michael R.; Araya, Paola S.; Lowell, Thomas V.; Aravena, Juan C.; Moreno, Patricio I.; Kelly, Meredith A.; Schaefer, Joerg M.

2018-05-01

Elucidating the timing and regional extent of abrupt climate events during the last glacial-interglacial transition (∼18-11.5 ka) is critical for identifying spatial patterns and mechanisms responsible for large-magnitude climate events. The record of climate change in the Southern Hemisphere during this time period, however, remains scarce and unevenly distributed. We present new geomorphic, chronological, and equilibrium line altitude (ELA) data from a climatically sensitive mountain glacier at Monte San Lorenzo (47°S), Central Patagonia. Twenty-four new cosmogenic 10Be exposure ages from moraines provide a comprehensive glacial record in the mid-latitudes of South America, which constrain the timing, spatial extent and magnitude of glacial fluctuations during the Antarctic Cold Reversal (ACR, ∼14.5-12.9 ka). Río Tranquilo glacier advanced and reached a maximum extent at 13.9 ± 0.7 ka. Three additional inboard moraines afford statistically similar ages, indicating repeated glacier expansions or marginal fluctuations over the ACR. Our record represents the northernmost robust evidence of glacial fluctuations during the ACR in southern South America, documenting not only the timing of the ACR maximum, but also the sequence of glacier changes within this climate event. Based on ELA reconstructions, we estimate a cooling of >1.6-1.8 °C at the peak of the ACR. The Río Tranquilo record along with existing glacial reconstructions from New Zealand (43°S) and paleovegetation records from northwestern (41°S) and central-west (45°S) Patagonia, suggest an uniform trans-Pacific glacier-climate response to an ACR trigger across the southern mid-latitudes. We posit that the equatorial migration of the southern westerly winds provides an adequate mechanism to propagate a common ACR signal across the Southern Hemisphere.

Evaluación del modelo WEPP para predecir la erosión hídrica en pastizales semiáridos del noreste de la Patagonia Evaluation of the WEPP model to predict soil erosion in northeastern Patagonian rangelands

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Marcelo P Chartier

2010-07-01

Full Text Available Los modelos matemáticos son herramientas útiles para la predicción de las pérdidas de suelo por erosión hídrica. El desarrollo reciente del modelo WEPP y su utilización para evaluar los riesgos de erosión en pastizales naturales ha significado un avance interesante en el campo de la erosión y la conservación de suelos de estos ecosistemas. En este trabajo examinamos la eficiencia del modelo WEPP para predecir los procesos hidrológicos y de erosión del suelo en los pastizales naturales semiáridos del noreste de la provincia de Chubut. Se identificaron tres comunidades de plantas ubicadas a lo largo de un gradiente de degradación del suelo: estepa herbácea con arbustos aislados (EH, estepa herbáceo-arbustiva (EHA y estepa arbustiva degradada (EA. En cada una de estas comunidades se aplicó una lluvia simulada (100 mm h-1 durante 30 min sobre parcelas de 1 m² (0,6 x 1,67 m y se colectó el escurrimiento y los sedimentos totales. A partir de los datos de la condición superficial de cada parcela se estimó el escurrimiento y la producción de sedimentos mediante el modelo WEPP. En este trabajo se observó una baja eficiencia del modelo WEPP para predecir el escurrimiento (Eficiencia, E = 0,14 y la erosión del suelo (E = -0,93. La predicción del escurrimiento y pérdida de suelo del modelo WEPP mostró mayor sensibilidad a cambios en los parámetros de lluvia y pendiente del terreno y una sensibilidad moderada a cambios en la cobertura, textura, erodabilidad del suelo y conductividad hidráulica efectiva. El escurrimiento y la producción de sedimentos estimados por WEPP fueron significativamente diferentes en las distintas comunidades de plantas (p Mathematical models are useful tools to predict soil loss by water erosion. The recent development of the WEPP model and its use in assessing the risks of erosion in rangelands has led to significant advances in the field of erosion and soil conservation of these ecosystems. In this

Does Nature and Persistence of Substrate at a Mesohabitat Scale Matter for Chironomidae Assemblages? a Study of Two Perennial Mountain Streams in Patagonia, Argentina

Science.gov (United States)

Epele, Luis Beltrán; Miserendino, María Laura; Brand, Cecilia

2012-01-01

of the Chironomidae assemblage at the habitat scale is significant for conservation purposes and for the management of low order streams in Patagonia. PMID:22947060

Does nature and persistence of substrate at a mesohabitat scale matter for Chironomidae assemblages? A study of two perennial mountain streams in Patagonia, Argentina.

Science.gov (United States)

Epele, Luis Beltrán; Miserendino, María Laura; Brand, Cecilia

2012-01-01

Chironomidae assemblage at the habitat scale is significant for conservation purposes and for the management of low order streams in Patagonia.

Trail impacts and trail impact management related to ecotourism visitation at Torres del Paine National Park, Chile

Science.gov (United States)

Farrell, T.A.; Marion, J.L.

2002-01-01

Ecotourism and protected area visitation in Central and South America are largely dependent upon a relatively undisturbed quality of natural resources. However, visitation may impact vegetation, soil, water and wildlife resources, and degrade visitor facilities such as recreation sites and trails. Findings are reported from trail impact research conducted at Torres del Paine National Park in Patagonia, Chile. The frequency and magnitude of selected trail impacts and the relative effect of the amount of use, vegetation type, trail position and trail grade are investigated. Findings differed from previous studies in that amount of use was significantly related to both trail width increases and trail erosion. Management actions to minimize trail impacts are offered.

Categorías de adscripción y dinámicas políticas en el norte patagónico a partir de la explotación de hidrocarburos Categories of adscription and political dynamics at North Patagonia starting from the hydrocarbon exploitation

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Analía García

2012-06-01

Full Text Available Buta Ranquil es un pueblo de la Patagonia argentina centrado en una ganadería de autosubsistencia donde, a principios de siglo, se inicia la explotación hidrocarburífera en un yacimiento aledaño. Las obras de construcción civil relacionadas con la producción de petróleo dan paso al arribo migratorio de obreros. En poco tiempo, se altera el estilo de vida tradicional y contrasta con la nueva dinámica social que trae aparejada la industria y el comercio. En el presente artículo, el objetivo es analizar cómo operan categorías de adscripción avaladas consuetudinariamente entre los pobladores originarios y la población migrante observando la dinámica política. Estas categorías de adscripción son de marcos conceptuales y estigmatizadores donde se sitúa la distancia social entre migrantes y originarios. Retomamos categorías antropológicas como las de “rumor” y “reputación” a fin de comprender de qué manera la experiencia social del nuevo contexto productivo impacta sobre el entramado sociocultural preexistente. Finalmente, sostendremos que las afinidades personales con base en estas categorías tensionan el cotidiano de alianzas políticas definidas en marcos regionales más amplios.At the beginning of the 21th century, hydrocarbon exploitation began in Buta Ranquil, an Argentine village situated in north Patagonia and grounded on a traditional peasant subsistence economy. There, civil construction related with oil production started and promoted the arrival of migrant workmen. In a very short period of time, the traditional peasant’s way of life started to change and contrast with the new social dynamics that the industry and commerce brought along. In this article, the objective is to analyze how consuetudinary categories of adscription work in a context of social change between the original inhabitants and migrants, focusing on the political dynamics. We argue that these categories serve as frameworks in which social

Influence of precipitation, landscape and hydrogeomorphic lake features on pelagic allochthonous indicators in two connected ultraoligotrophic lakes of North Patagonia

Energy Technology Data Exchange (ETDEWEB)

Queimalinos, Claudia, E-mail: queimalinosc@comahue-conicet.gob.ar [Laboratorio de Fotobiologia, Instituto de Investigaciones en Biodiversidad y Medio Ambiente (INIBIOMA, UNComahue-CONICET), Quintral 1250, R8400FRF Bariloche, Rio Negro (Argentina); Reissig, Mariana; Dieguez, Maria del Carmen [Laboratorio de Fotobiologia, Instituto de Investigaciones en Biodiversidad y Medio Ambiente (INIBIOMA, UNComahue-CONICET), Quintral 1250, R8400FRF Bariloche, Rio Negro (Argentina); Arcagni, Marina; Ribeiro Guevara, Sergio [Laboratorio de Analisis por Activacion Neutronica (LAAN), Centro Atomico Bariloche, Comision Nacional de Energia Atomica, Av. Bustillo 9500, R8402AGP Bariloche, Rio Negro (Argentina); Campbell, Linda [School of Environmental Studies, Saint Mary' s University, 923 Robie Street, Halifax, Nova Scotia, Canada B3H-3C3 (Canada); Soto Cardenas, Carolina [Laboratorio de Fotobiologia, Instituto de Investigaciones en Biodiversidad y Medio Ambiente (INIBIOMA, UNComahue-CONICET), Quintral 1250, R8400FRF Bariloche, Rio Negro (Argentina); Rapacioli, Raul [Facultad de Ingenieria, Universidad Nacional del Comahue, Buenos Aires1400, Q8300IBX Neuquen (Argentina); and others

2012-06-15

We investigated the terrestrial influence on two chained deep ultraoligotrophic lakes of North Patagonia (Argentina) through the seasonal analysis of two pelagic allochthonous indicators: i) water color, as a proxy of allochthonous dissolved organic matter in lakes; and ii) the color to chlorophyll a ratio (Color:Chla), as an indicator of the relationship between allochthonous and autochthonous carbon pools. We also evaluated the potential transfer pathways of the allochthonous dissolved organic matter into the pelagic food webs of these deep lakes, including the natural zooplankton {delta}{sup 13}C in the analysis. The dynamics of the allochthonous indicators were related to the precipitation regime, water level fluctuations, and hydrogeomorphic and catchment features of lakes Moreno East and Moreno West. The water color (absorbance at 440 nm) was extremely low (< 0.28 m{sup -1}) in both lakes regardless of the season. However, precipitation and snowmelt regimes drove the increase and decrease of water color, respectively. A significant positive relationship between the zooplankton bulk {delta}{sup 13}C with the water color would suggest an input of allochthonous organic carbon into the pelagic consumers. The incorporation of the dissolved allochthonous material into higher trophic levels is likely favored by the bacterivorous behavior of planktonic organisms, mixotrophic flagellates and ciliates, which dominate the pelagic food webs of these Patagonian lakes. Morphometric aspects, mainly the higher water residence time, led to lower values of allochthony in Moreno East compared to Moreno West, probably accentuated by its upper position in the lake chain. Overall, our results suggest that these allochthonous signals can bring insight into the magnitude of the interaction between terrestrial environments and lake ecosystems, even in extremely clear and ultraoligotrophic systems, such as the Andean Patagonian lakes. - Highlights: Black-Right-Pointing-Pointer Pelagic

Mammalia, Rodentia, Sigmodontinae, Holochilus brasiliensis (Desmarest, 1819: Distribution extention

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Formoso, A. E.

2010-01-01

Full Text Available We report the southernmost record for the marsh rats Holochilus brasiliensis 20 km S of Pedro Luro on Hwy3, province of Buenos Aires, Argentina (39°41’31.13”S, 62°40’23.5”W extending the range of the species ca. 110 km S.This represents the first contemporaneous record of H. brasiliensis in Patagonia, and also the only species of sigmodontinerodent with amphibious habits reported in Patagonia.

Is banking supervision central to central banking?

OpenAIRE

Joe Peek; Eric S. Rosengren; Geoffrey M. B. Tootell

1997-01-01

Whether central banks should play an active role in bank supervision and regulation is being debated both in the United States and abroad. While the Bank of England has recently been stripped of its supervisory responsibilities and several proposals in the United States have advocated removing bank supervision from the Federal Reserve System, other countries are considering enhancing central bank involvement in this area. Many of the arguments for and against these proposals hinge on the effe...

Anotrichium furcellatum (Ceramiaceae, Rhodophyta en Argentina: Una posible especie invasora Anotrichium furcellatum (Ceramiaceae, Rhodophyta in Argentina: A possible invasive species

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Alicia L. Boraso de Zaixso

2005-12-01

Full Text Available Se reporta la presencia de al menos dos poblaciones de Anotrichium en la costa argentina (provincias de Buenos Aires, Chubut y Santa Cruz. Las poblaciones submareales observadas estaban caracterizadas por una mayoría de talos en estado vegetativo. Solo las poblaciones intermareales mostraron tetrasporofitos con esporangios. Las poblaciones se identificaron provisionalmente de acuerdo a la morfología del talo y de los tetrasporangios como Anotrichium furcellatum (J. Agardh Baldock. Las características de los talos de las poblaciones estudiadas son comparadas con las de las especies de Anotrichium que poseen igualmente pocos tetrasporangios por célula. Se reportan arribazones inusualmente abundantes de esta especie ocurridas en la costa bonaerense en el año 2000.At least two populations of Anotrichium are reported from the coast of Argentina (Buenos Aires, Chubut, and Santa Cruz provinces. These populations have a majority of vegetative thalli. According with their morphological and tetrasporangial characteristics the populations are provisionally assigned to Anotrichium furcellatum (J. Agardh Baldock. The characteristics of the thalli of studied populations are compared with the species of Anotrichium having also a low number of tetrasporangia per cell. Extraordinary high quantities of cast ashore thalli of this species is reported along the Buenos Aires province coast in the year 2000.

The Gondwana Orogeny in northern North Patagonian Massif: Evidences from the Caita Có granite, La Seña and Pangaré mylonites, Argentina

Directory of Open Access Journals (Sweden)

Daniel A. Gregori

2016-07-01

Full Text Available Structural analyses in the northern part of the North Patagonia Massif, in the foliated Caita Có granite and in La Seña and Pangaré 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 Có 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.

Postfire encroachment of Fabiana imbricata is real? Assessing changes of shrubland occupation during 40 years in NW Patagonia steppe

Science.gov (United States)

Lasaponara, Rosa; Oddi, Facundo; Ghermandi, Luciana

2014-05-01

Landscapes are dynamic in space and time, being spatio-temporal processes of particular interest for landscape ecology. In particular, grasslands can change their structure through the expansion of shrubs in the landscape matrix. Shrub encroachment affect biodiversity as well as forage availability that is the key component of the productive use of rangelands. However, despite its recognition as a global problem, knowledge on the rates, dynamics and encroachment patterns is even scarce. For example, although it is generally accepted that fire control shrub encroachment, certain shrubby species could be favored by the occurrence of fire. In northwestern Patagonian steppe, Fabiana imbricata form large monospecific shrublands that are part of the landscape mosaic and its dynamics of regeneration is strongly related to fire. This long-lived shrub (≡ 150 years) is a typical seeder that is killed by fire and recruits seedlings almost exclusively in post-fire, establishing even-age patches. Our objective was to determine whether F. imbricata shrublands have expanded during the last 40 years in a landscape fire prone. The study area corresponds to San Ramon ranch (22,000 ha) located in northwestern Patagonia steppe, Argentina (latitude -41° 04'; longitude -70° 51'). Two distribution maps of the species were made that corresponds to the study area in 1968 and 2011. The 1968 map was elaborated from the digitalization of aerial photographs (1:45000) while the 2011 map was produced with very high resolution satellite images, current aerial photographs and GPS field data. Both maps were loaded into a GIS environment, in which landscape metrics at patch and class level were determined and then compared. From remote sensing and dendroecological techniques, we know that the study area was almost entirely affected by fires during the study period. Therefore, the comparison of both maps allows us to know post-fire changes in the shrublands spatial configuration at the landscape

Central Nervous System Vasculitis

Science.gov (United States)

... of Vasculitis / Central Nervous System (CNS) Vasculitis Central Nervous System (CNS) Vasculitis Swap out your current Facebook Profile ... Facebook personal page. Replace with this image. Central nervous system (CNS) vasculitis is inflammation of blood vessel walls ...

Evolution of the mantle source in an evolving arc-backarc system (Torres del Paine, Patagonia): Evidence from Hf isotopes in zircon

Science.gov (United States)

Ewing, T. A.; Muntener, O.; Leuthold, J.; Baumgartner, L. P.; Putlitz, B.; d'Abzac, F. X.; Chiaradia, M.

2015-12-01

The Miocene Torres del Paine intrusive complex (TPIC) in Patagonia is a transitional alkaline backarc intrusion1 emplaced on short timescales of 162 ± 11 ka2. It is subdivided into two units with distinct ages of ~12.6 Ma and ~12.45 Ma1. Smaller intrusive bodies in the area record a change in chemistry from calc-alkaline at ~16 Ma, to transitional alkaline at ~12.5 Ma. Zircons from ~16 Ma intrusives and the 12.6 Ma part of the TPIC have remarkably consistent, slightly enriched Hf isotope compositions with ɛHf(i) of -1 to +2. An abrupt shift towards more juvenile Hf isotope compositions is observed in the ~12.45 Ma part of the TPIC, with ɛHf(i) of +3 to +6. Bulk rock Nd and Sr isotopes for the TPIC show the same shift towards more juvenile compositions at this time1. The long-term consistency of ɛHf(i) from 16 to 12.6 Ma is surprising, given that in the same period the bulk rock chemistry changes from calc-alkaline to transitional alkaline. Conversely, the major shift in ɛHf(i) is not correlated with any change in bulk rock chemistry, which remains transitional alkaline from 12.6 to 12.45 Ma. The decoupling of major element chemical evolution and Hf isotope signatures suggests that the subsequent rapid influx of juvenile material recorded by our Hf isotope data must have occurred by renewed mantle melting. Subduction of the Chile ridge at ~12.5 Ma in this area caused arc magmatism to move westwards and back-arc extension to initiate. We propose that the first TPIC magmas (12.6 Ma) came from a mantle wedge with a residual subduction signature. Subsequent melting of more juvenile mantle, less contaminated by a subduction component, generated the 12.45 Ma TPIC magmas. These results demonstrate that magmatic complexes such as the TPIC may tap distinct mantle sources even on very short timescales, fingerprinting arc-backarc transition processes. 1Leuthold et al., 2013, JPET, 54: 273-303 2Leuthold et al., 2012, EPSL, 325: 85-92

Outsourcing central banking

DEFF Research Database (Denmark)

Khoury, Sarkis Joseph; Wihlborg, Clas

2005-01-01

The literature on Currency Boards (CB) stops at the water edge in terms of dealing with the totality of the functions of a central bank. Monetary policy, and banking supervisioncan be "outsourced" in an open economy with substantial foreign direct investment (FDI)in the banking sector if political...... nationalism does not trump economic rationality. An orthodox CB renders the central banking function redundant in terms of interest rate and exchange rate determination. FDI in banking could perform the same role for the supervisory function of central banks. We use the case of Estonia to illustrate...... the feasibility of, and constraints on, outsourcing of central bank functions. A brief discussion of the Argentinian experience is used for contrast.Key words: Currency Board, Foreign Banks, Supervision, Regional Integration,outsourcing....

Del Recurso Humano al humano con recursos: una propuesta en el estudio de encadenamientos socioproductivos para el Turismo de intereses especiales en el territorio Patagonia Verde Chile

Directory of Open Access Journals (Sweden)

Guillermo Sebastián Pacheco Habert

2012-01-01

Full Text Available El tema del humano con recurso, enfoque de este trabajo, tiene un papel importantísimo a la hora de transitar de estrategias competitivas hacia estrategias colaborativas, sobre todo cuando se perciben logros ecosocioeconómicos que avanzan hacia la dirección de un desarrollo territorial. Se tiene como hipótesis, que desde el enfoque de los encadenamientos socioproductivos, centrado en el turismo de intereses especiales, es posible comprender y establecer objetivos comunes dentro de actores, organizaciones, emprendimientos y comunidades locales. El objetivo de este artículo es proponer una aproximación teórica sobre el TIE (Turismo de Intereses Especiales sobre las aglomeraciones, sobre los encadenamientos socioproductivos y sobre el enfoque del humano con recurso, para posteriormente relatar los primeros resultados de esta investigación realizada en los cinco municipios que hacen parte del territorio turístico denominado "Patagonia Verde", en el sur de Chile. A partir de la identificación de actores clave, se aplicaron entrevistas a éstos y fichas de caracterización a emprendimientos. Posteriormente se identificaron fortalezas y oportunidades que puedan ser potenciadas a partir de la perspectiva del humano con recurso. A partir de los encadenamientos socioproductivos, contar con individuos conscientes y proactivos dentro de las instituciones y organizaciones en tareas y ejes estratégicos del desarrollo turístico y que compartan con la perspectiva del desarrollo territorial sustentable, es uno de los desafíos que aquí proponemos. Son los sujetos quienes son capaces de generar las condiciones institucionales para otra forma de comprender y actuar en Turismo.

NIDDK Central Repository

Data.gov (United States)

U.S. Department of Health & Human Services — The NIDDK Central Repository stores biosamples, genetic and other data collected in designated NIDDK-funded clinical studies. The purpose of the NIDDK Central...

CENTRAL PLATEAU REMEDIATION

International Nuclear Information System (INIS)

ROMINE, L.D.

2006-01-01

A systematic approach to closure planning is being implemented at the Hanford Site's Central Plateau to help achieve the goal of closure by the year 2035. The overall objective of Central Plateau remediation is to protect human health and the environment from the significant quantity of contaminated material that resulted from decades of plutonium production in support of the nation's defense. This goal will be achieved either by removing contaminants or placing the residual contaminated materials in a secure configuration that minimizes further migration to the groundwater and reduces the potential for inadvertent intrusion into contaminated sites. The approach to Central Plateau cleanup used three key concepts--closure zones, closure elements, and closure process steps--to create an organized picture of actions required to complete remediation. These actions were merged with logic ties, constraints, and required resources to produce an integrated time-phased schedule and cost profile for Central Plateau closure. Programmatic risks associated with implementation of Central Plateau closure were identified and analyzed. Actions to mitigate the most significant risks are underway while high priority remediation projects continue to make progress

Actual versus Perceived Central Bank Transparency : The Case of the European Central Bank

NARCIS (Netherlands)

van der Cruijsen, C.A.B.; Eijffinger, S.C.W.

2007-01-01

Central banks have become more and more transparent about their monetary policy making process. In the central bank transparency lit- erature the distinction between actual and perceived central bank trans- parency is often lacking. However, as perceptions are crucial for the ac- tions of economic

Nuevo hospedador de Huequenia livida (Coleoptera: Cerambycidae en Argentina

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José María VILLACIDE

2006-01-01

Full Text Available La presencia de adultos de Huequenia livida (Germain, 1898 (Cerambycidae fue detectada en una plantación de Pinus contorta Douglas ex Loudon var. murrayana (Balf. Engelm. en la localidad de Lago Puelo (Chubut, Argentina. Este es el primer registro del desarrollo de H. livida en una especie hospedadora distinta de Araucaria spp. Esta contribución agrega una nueva especie y una nueva familia al listado de plantas hospedadoras descriptas para este Cerambycidae en Chile.

Nuevo hospedador de Huequenia livida (Coleoptera: Cerambycidae) en Argentina

OpenAIRE

José María VILLACIDE; Paula SACKMANN; Mario ELGUETA

2006-01-01

La presencia de adultos de Huequenia livida (Germain, 1898) (Cerambycidae) fue detectada en una plantación de Pinus contorta Douglas ex Loudon var. murrayana (Balf.) Engelm. en la localidad de Lago Puelo (Chubut, Argentina). Este es el primer registro del desarrollo de H. livida en una especie hospedadora distinta de Araucaria spp. Esta contribución agrega una nueva especie y una nueva familia al listado de plantas hospedadoras descriptas para este Cerambycidae en Chile.

On the distribution of Rostkovia magellanica (Juncaceae) - a species newly rediscovered in Ecuador

DEFF Research Database (Denmark)

Balslev, Henrik

1979-01-01

Rostkovia magellanica has hitherto been considered a species of Patagonia and the subantarctic islands from New Zealand to South Georgia. An old report from Ecuador has been considered erroneous, but it has now been rediscovered there. Brief notes on the ecology of the species are given, and the ......Rostkovia magellanica has hitherto been considered a species of Patagonia and the subantarctic islands from New Zealand to South Georgia. An old report from Ecuador has been considered erroneous, but it has now been rediscovered there. Brief notes on the ecology of the species are given...

Paleoecología: el uso de los quironómidos fósiles (Diptera: Chironomidae en reconstrucciones paleoambientales durante el Cuaternario en la Patagonia

Directory of Open Access Journals (Sweden)

Julieta MASSAFERRO

2009-01-01

Full Text Available Entre los indicadores biológicos lacustres más utilizados en las reconstrucciones ambientales, se encuentran el polen, los ostrácodos y las diatomeas, y entre los insectos, los coleópteros y los quironómidos. Este grupo ha cobrado gran importancia en los últimos tiempos, debido a los resultados prometedores que se han obtenido en reconstrucciones climáticas realizadas en América del Norte y Europa. En América del Sur, el uso de los quironómidos fósiles en estudios cuaternarios es relativamente limitado, principalmente por su escaso conocimiento taxonómico regional. La mayor parte de estos estudios fueron realizados en lagos glaciares patagónicos de Argentina y Chile. Las larvas de quironómidos constituyen una valiosa herramienta paleolimnológica, por ser un grupo de organismos altamente sensible a cambios ambientales, tanto naturales como artificiales. Además, es un grupo de insectos ampliamente distribuido y con una abundancia y diversidad relativamente altas. Sus cápsulas cefálicas se preservan en los sedimentos lacustres y poseen caracteres importantes que permiten identificar géneros y muchas veces especies. El estudio de los ensambles de quironómidos en sedimentos lacustres puede ser utilizado con distintos objetivos, por ejemplo, para estudios de eutrofización, ya que responden rápidamente a cambios en la concentración de nutrientes, materia orgánica y otros elementos, como metales pesados. No obstante, uno de los potenciales más importantes de este grupo de insectos es su sensibilidad a los cambios de temperatura, por este motivo, la aplicación más importante de su estudio en sedimentos se centra en las reconstrucciones climáticas. Esta contribución es una síntesis de los resultados de los trabajos publicados en la Patagonia argentina y chilena, sobre la base del uso de los quironómidos fósiles en reconstrucciones paleoambientales.

SECURITY THREATS IN CENTRAL ASIA

Directory of Open Access Journals (Sweden)

Çağla Gül Yesevi

2013-07-01

Full Text Available This study will analyze main security threats in Central Asia. It is obvious thatsince the end of Cold War, there have been many security threats in Central Asiaas internal weakness of Central Asian states, terrorism, transnational crime,economic insecurity, environmental issues, drug trafficking, ethnic violence,regional instability. This study will propose thatwith increasing interdependence,states need each other to solve these global security problems. In that sense,regional and sub-regional cooperation between Central Asian states and with otherregional actors has been witnessed. It is clear that the withdrawal of NATO fromAfghanistan will destabilize Central Asia. This study will investigate overallsecurity situation in Central Asia and affects andcontributions of regionalorganizations to Eurasian security

Ventajas competitivas: Una propuesta paso a paso de búsqueda y aplicación de cadena de valor adaptada a empresas aéreas. Caso Patagonia- Argentina

Directory of Open Access Journals (Sweden)

María Alejandra Gazzera

2005-05-01

Full Text Available El desarrollo del proceso de búsqueda de ventajas competitivas de una empresa se puede plantear como un esfuerzo que se sigue en tres grandes líneas de actuación: la búsqueda centrada en la empresa, centrada en el entorno, y centrada en los competidores. Si bien la búsqueda de ventajas competitivas está estrechamente interrelacionada y vinculada entre las tres líneas, el presente trabajo se centrará en la primera de ellas, es decir al interior de la empresa, sin perder de vista la relación que tienen las empresas con su entorno o mercado, mediante la aplicación de la cadena de valor de Michael Porter (1985 adaptada a las empresas aéreas que operaban desde y hacia la ciudad de Neuquen, puerta de entrada a la Patagonia Argentina Es necesario destacar que no existen al presente, año 2005, estudios de este tipo en el sector mencionado en Argentina, pero en otros sectores productivos y aún en empresas aéreas de otros países, la cadena de valor ha demostrado su utilidad como tecnología de reflexión estratégica para generar valor en el cliente y para dirigir los esfuerzos de la empresa hacia la consolidación o creación de ventajas competitivas sostenibles en el tiempo.

Demographic tensions in Central America.

Science.gov (United States)

1986-08-01

This discussion of Central America focuses on the rapid growth of its population, its stagnating economy, and those countries that are socioeconomically advanced. Between 1950-85 the population of Central America tripled, from 9.1 million to 26. 4 million, due to marked mortality declines and the absence of off-setting fertility declines. The distribution of Central Americas's growing populations sets its population growth apart from that of other developing regions. Currently, almost half of all Central Americans live in cities. Although the average growth rate for Central American countries has fallen and is expected to drop further, the decline does not counterbalance the effect of the absolute rise in population numbers. The average annual growth rate of more than 3% annually in the 1960s fell to about 2.6% in recent years, but this decline is due primarily to socioeconomically advanced Costa Rica and Panama. Central America's age structure further complicates the population crisis. About 43% of Central Americans are under the age of 15. When the increasingly larger young population group enters it reproductive years, the potential for future growth (albeit the falling rate of population increase) is unparalleled. UN population projections show the region's population at 40 million by the year 2000. The 1973 oil crisis began a downward spiral for the buoyant post World War II Central American economy. Between 1950-79, real per capita income growth in Central America doubled, with Central American economies growing an average of 5.3% annually. By the early 1980s, overseas markets of the trade-dependent countries of Central America had dried up due to protectionism abroad and slumping basic commodity prices. These and other factors plunged Central America into its current economic malaise of falling real per capita income, rising unemployment, curtailed export led economic growth, and a rising cost of living. In general, economic growth in Central America

Europa central

Directory of Open Access Journals (Sweden)

Karel BARTOSEK

2010-02-01

Full Text Available La investigación francesa continúa interesándose por Europa Central. Desde luego, hay límites a este interés en el ambiente general de mi nueva patria: en la ignorancia, producto del largo desinterés de Francia por este espacio después de la Segunda Guerra Mundial, y en el comportamiento y la reflexión de la clase política y de los medios de comunicación (una anécdota para ilustrar este ambiente: durante la preparación de nuestro coloquio «Refugiados e inmigrantes de Europa Central en el movimiento antifascista y la Resistencia en Francia, 1933-1945», celebrado en París en octubre de 1986, el problema de la definición fue planteado concreta y «prácticamente». ¡Y hubo entonces un historiador eminente, para quién Alemania no formaría parte de Europa Central!.

From Chilean Patagonia to Galapagos, Ecuador: novel insights on blue whale migratory pathways along the Eastern South Pacific

Directory of Open Access Journals (Sweden)

Rodrigo Hucke-Gaete

2018-04-01

Full Text Available Background The most traditional scheme for migration among baleen whales comprises yearly migrations between productive waters at high latitude summer feeding grounds and warmer waters at lower latitudes where whales calve and mate, but rarely feed. Evidence indicates, however, that large departures from this scheme exist among populations and individuals. Furthermore, for some populations there is virtually no information on migratory pathways and destinations. Such is the case of Chilean blue whales throughout the Eastern South Pacific; hence, the goal of this study was to assess its migratory behavior. Methods Dedicated marine surveys and satellite tagging efforts were undertaken during the austral summer and early autumn on blue whale feeding grounds off Chilean Northern Patagonia (CNP during 2013, 2015 and 2016. Positional data derived from satellite tags regarding movement patterns and behavior were analyzed using Bayesian switching first-difference correlated random walk models. Results We instrumented 10 CNP blue whales with satellite transmitters and documented individual variation in departure time, northbound migratory routes and potential wintering grounds. The onset of migration occurred from mid/late austral autumn to well into the austral winter. Blue whales moved in various directions, but ultimately converged toward a general NW movement direction along a wide corridor exceeding 2,000 km. Area-Restricted Search behavior was exhibited within fjords and channels of CNP and also South of Galapagos Archipelago (GA and northern Peru, but never during migration. Interestingly, dive profiles for one whale that reached GA showed a sharp and consistent increase in depth north of 5°S and extreme deep dives of up to 330 m. Discussion Information derived from satellite tagged blue whales in this study is the first of its kind off the Eastern Southern Pacific. Our results provide valuable information on their migratory timing, routes and

Nuevo hospedador de Huequenia livida (Coleoptera: Cerambycidae) en Argentina New host record for Huequenia livida (Coleoptera: Cerambycidae) in Argentina

OpenAIRE

José María Villacide; Paula Sackmann; Mario Elgueta

2006-01-01

La presencia de adultos de Huequenia livida (Germain, 1898) (Cerambycidae) fue detectada en una plantación de Pinus contorta Douglas ex Loudon var. murrayana (Balf.) Engelm. en la localidad de Lago Puelo (Chubut, Argentina). Este es el primer registro del desarrollo de H. livida en una especie hospedadora distinta de Araucaria spp. Esta contribución agrega una nueva especie y una nueva familia al listado de plantas hospedadoras descriptas para este Cerambycidae en Chile.Adult of Huequenia liv...

Population structure and reticulate evolution of Saccharomyces eubayanus and its lager-brewing hybrids.

Science.gov (United States)

Peris, David; Sylvester, Kayla; Libkind, Diego; Gonçalves, Paula; Sampaio, José Paulo; Alexander, William G; Hittinger, Chris Todd

2014-04-01

Reticulate evolution can be a major driver of diversification into new niches, especially in disturbed habitats and at the edges of ranges. Industrial fermentation strains of yeast provide a window into these processes, but progress has been hampered by a limited understanding of the natural diversity and distribution of Saccharomyces species and populations. For example, lager beer is brewed with Saccharomyces pastorianus, an alloploid hybrid of S. cerevisiae and S. eubayanus, a species only recently discovered in Patagonia, Argentina. Here, we report that genetically diverse strains of S. eubayanus are readily isolated from Patagonia, demonstrating that the species is well established there. Analyses of multilocus sequence data strongly suggest that there are two diverse and highly differentiated Patagonian populations. The low nucleotide diversity found in the S. eubayanus moiety of hybrid European brewing strains suggests that their alleles were drawn from a small subpopulation that is closely related to one of the Patagonian populations. For the first time, we also report the rare isolation of S. eubayanus outside Patagonia, in Wisconsin, USA. In contrast to the clear population differentiation in Patagonia, the North American strains represent a recent and possibly transient admixture of the two Patagonian populations. These complex and varied reticulation events are not adequately captured by conventional phylogenetic methods and required analyses of Bayesian concordance factors and phylogenetic networks to accurately summarize and interpret. These findings show how genetically diverse eukaryotic microbes can produce rare but economically important hybrids with low genetic diversity when they migrate from their natural ecological context. © 2014 John Wiley & Sons Ltd.

Central Banking after the Crisis

OpenAIRE

Frederick S. Mishkin

2013-01-01

This paper explores where central banking is heading after the recent financial crisis. First it discusses the central bank consensus before the crisis and then outlines the key facts learned from the crisis that require changes in the way central banks conduct their business. Finally, it discusses four main areas in which central banks are altering their policy frameworks: 1) the interaction between monetary and financial stability policies, 2) nonconventional monetary policy, 3) risk manage...

Central ignition scenarios for TFTR

International Nuclear Information System (INIS)

Zweben, S.J.; Redi, M.H.; Bateman, G.

1986-03-01

The possibility of obtaining ignition in TFTR by means of very centrally peaked density profiles is examined. It is shown that local central alpha heating can be made to exceed local central energy losses (''central ignition'') under global conditions for which Q greater than or equal to 1. Time dependent 1-D transport simulations show that the normal global ignition requirements are substantially relaxed for plasmas with peaked density profiles. 18 refs., 18 figs

Variación de la composición de ácidos grasos de membrana celular de Rhodococcus rodochrous GNP-OHP-38r en respuesta a la temperatura y salinidad Variation in the composition of Rhodococcus rodochrous GNP-OHP-38r cell membrane fatty acids in response to temperature and salinity

Directory of Open Access Journals (Sweden)

G.N. Pucci

2004-06-01

Full Text Available Los integrantes del género Rhodococcus son habitantes frecuentes y abundantes de áreas contaminadas con hidrocarburos y resisten la creciente salinidad que se presenta en la Patagonia central. Este género tiene buena capacidad de eliminar contaminantes hidrocarburos que constituyen el mayor contaminante de la región. En el presente trabajo se estudió la respuesta en la composición de sus ácidos grasos de una cepa aislada de un sistema de landfarming, ante la acción combinada de diferentes temperaturas y concentraciones salinas. La estrategia de la cepa Rhodococcus rodochrous GNP-OHP-38r frente al incremento de temperatura, es el aumento del porcentaje de los ácidos grasos saturados totales (n:0; ácidos grasos ramificados en el carbono terminal con grupos oxidrilo en posición 2 (n:0 iso 2 OH y saturados con grupo metilo en carbono 10 (n:0 10 metil, a expensas de la disminución del porcentaje de los n:1 cis.The members of the genus Rhodococcus are frequent and abundant inhabitants of polluted areas with hydrocarbons and they resist the salinity present in the central Patagonia. This genus has good capacity to eliminate pollution produced by hydrocarbons that constitutes the biggest pollutant agent in the region. The present work studies the answer in the composition of its fatty acids under the combined action of the temperature and saline concentration of an isolated stump of a landfarming system. The strategy of Rhodococcus rodochrous strain GNP-OHP-38r in front of the thermal-osmotic stress is the increase of the percentage of the total saturated fatty acids (n:0; fatty acids branched in the terminal carbon with hidroxyl group in position 2 (n:0 iso 2 OH and saturated with group methyl in carbon 10 (n:0 10 metil when the temperature is increased. These acids increase while the percentage of n:1 cis decrease.

Sirenophila ovis-atra a new species of maritime Teloschistaceae from the Southern Hemisphere

DEFF Research Database (Denmark)

Søchting, Ulrik; Søgaard, Majbrit Zeuthen; Sancho, Leopoldo G.

2016-01-01

A new species, Sirenophila ovis-atra is described from maritime rocks of southern Patagonia, the Falkland Islands and Macquarie Island, where it grows in the upper part of the black ‘Verrucaria-zone’, most often on members of the genus Hydropunctaria. It is so far the only known species of Sireno......A new species, Sirenophila ovis-atra is described from maritime rocks of southern Patagonia, the Falkland Islands and Macquarie Island, where it grows in the upper part of the black ‘Verrucaria-zone’, most often on members of the genus Hydropunctaria. It is so far the only known species...

Seasonal variability of primary production in a fjord ecosystem of the Chilean Patagonia: Implications for the transfer of carbon within pelagic food webs

Science.gov (United States)

Montero, Paulina; Daneri, Giovanni; González, Humberto E.; Iriarte, Jose Luis; Tapia, Fabián J.; Lizárraga, Lorena; Sanchez, Nicolas; Pizarro, Oscar

2011-03-01

We characterized the seasonal cycle of productivity in Reloncaví Fjord (41°30'S), Chilean Patagonia. Seasonal surveys that included measurements of gross primary production, community respiration, bacterioplankton secondary production, and sedimentation rates along the fjord were combined with continuous records of water-column temperature variability and wind forcing, as well as satellite-derived data on regional patterns of wind stress, sea surface temperatures, and surface chlorophyll concentrations. The hydrography and perhaps fjord productivity respond to the timing and intensity of wind forcing over a larger region. Seasonal changes in the direction and intensity of winds, along with a late-winter improvement in light conditions, may determine the timing of phytoplankton blooms and potentially modulate productivity cycles in the region. Depth-integrated gross primary production estimates were higher (0.4-3.8 g C m -2 d -1) in the productive season (October, February, and May), and lower (0.1-0.2 g C m -2 d -1) in the non-productive season (August). These seasonal changes were also reflected in community respiration and bacterioplankton production rates, which ranged, respectively, from 0.3 to 4.8 g C m -2 d -1 and 0.05 to 0.4 g C m -2 d -1 during the productive and non-productive seasons and from 0.05 to 0.6 g C m -2 d -1 and 0.05 to 0.2 g C m -2 d -1 during the same two periods. We found a strong, significant correlation between gross primary production and community respiration (Spearman, r=0.95; p100%, suggesting the use of allochthonous carbon sources by bacterioplankton when the levels of gross primary production are low. Low primary production rates were associated with a greater contribution of small cells to autotrophic biomass, highlighting the importance of small-sized plankton and bacteria for carbon cycling and fluxes during the less productive winter months. Fecal pellet sedimentation was minimal during this period, also suggesting that most of

Colloquium on Central Asia; Colloque sur l'Asie centrale

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

This colloquium on Azerbaijan was organized by the direction of international relations of the French Senate and the French center of foreign trade (CFCE). This document gathers the interventions of the participants and the debates with the audience following these interventions. The topics treated concern: - the present day political-economical situation of Central Asia countries (problem of borders, relations with Russia and China); - the economies of Central Asia countries: short term problems and medium-term perspectives; - the relations with the European Union (political, economical, trade and investments, perspectives); - the European energy stakes of Caspian sea (oil and gas reserves, development of hydrocarbon resources, exploitation and transport constraints, stakes for Europe and France); - TotalFinaElf company in Central Asia (Kazakhstan, Azerbaijan, enclavement problem); - the economical impacts of the TRACECA pathway (Transport Corridor Europe Caucasus Asia). (J.S.)

Alpha current flow betweenness centrality

NARCIS (Netherlands)

Avrachenkov, K.; Litvak, Nelli; Medyanikov, V.; Sokol, M.

2013-01-01

A class of centrality measures called betweenness centralities reflects degree of participation of edges or nodes in communication between different parts of the network. The original shortest-path betweenness centrality is based on counting shortest paths which go through a node or an edge. One of

Micro-environmental changes induced by shape and size of forest openings: effects on Austrocedrus chilensis and Nothofagus dombeyi seedlings performance in a Pinus contorta plantation of Patagonia, Argentina

Energy Technology Data Exchange (ETDEWEB)

Pafundi, L.; Urretavizcaya, M.F.; Defosse, G.E.

2016-07-01

Aim of the study: to analyze, within a Pinus contorta plantation, the effects of artificially created small rectangular and small medium circular canopy gaps on: i) photosynthetic active radiation (PAR), and soil temperature and moisture, and ii) survival and growth of planted Austrocedrus chilensis and Nothofagus dombeyi seedlings, species which formerly composed the natural forest of the area. Study area: A 2 ha stand of a Pinus contorta stand in Los Alerces National Park, Argentina (42°43’S, 71°43’W, 490 m.a.s.l.). Material and methods: The Pinus contorta stand was 25 yr old, 22 m height and 26 cm DBH, presenting 1000 trees ha-1 of density and 53 m2 ha-1 of basal area. In 2009, rectangular and circular gaps were created within the stand and then seedlings were planted. During two growing seasons (2010-2011 and 2011-2012), PAR, soil temperature and moisture were measured in gaps and understory (control), and seedling survival and growth in gaps. Main results: During both seasons, soil temperature did not differ among gaps and control, whereas PAR and soil moisture were lower in control than in gaps. Seedling survival was high in all gaps regardless of species and season. Seedlings showed higher diameter growth in rectangular than in circular gaps. Research highlights: Austrocedrus chilensis and N. dombeyi seedlings survival is high and their growth slightly affected, when planted in differently-sized canopy gaps within a Pinus contorta plantation in Patagonia. However, other gap sizes and stand densities should be tested before recommending which one shows better results for reconverting monocultures into former native forests. Abbreviations used: PAR (Photosynthetic Active Radiation); DBH (Diameter at Breast Height); INTA (Argentinean Institute of Agricultural Technology); IFONA (Argentinean Forest Institute). (Author)

Observations of central stars

International Nuclear Information System (INIS)

Lutz, J.H.

1978-01-01

Difficulties occurring in the observation of central stars of planetary nebulae are reviewed with emphasis on spectral classifications and population types, and temperature determination. Binary and peculiar central stars are discussed. (U.M.G.)

The diet of the South American sea lion (Otaria flavescens at Río Negro, Patagonia, Argentina, during the winter-spring period Dieta del lobo marino de un pelo sudamericano (Otaria flavescens en Río Negro, Patagonia, Argentina, durante el invierno y primavera

Directory of Open Access Journals (Sweden)

Raimundo L. Bustos

2012-12-01

Full Text Available The South American sea lion, Otaria flavescens (Shaw, 1800 population is steadily expanding along the Patagonian coast of Argentina in the last decades. However, little is known about the feeding ecology of the species in the area. The aim of this study was to analyze the food habits of O. flavescens from 91 scats collected at Río Negro province, during the winter and spring of 2005. Fish occurred in 96% of scats containing prey remains, followed by cephalopods (26%. Raneya brasiliensis (Kaup, 1856 was the most frequent and abundant species occurring in 58.6% of samples and constituting almost 50% of fish predated. Second in importance were Porichthys porosissimus (Cuvier, 1829 and Cynoscion guatucupa (Cuvier, 1830 in terms of occurrence (%FO 20.7 and numbers (29.6% respectively. The squid Loligo gahi (d'Orbigny, 1835 was the most frequent cephalopod prey (42.1%, whereas Octopus tehuelchus (d'Orbigny, 1834 was the most abundant (77%. The higher amount and diversity of prey found in the spring in comparison with the winter season might be related to a higher feeding activity of seals or to a seasonal increase in food availability in the area.La población del lobo marino de un pelo sudamericano Otaria flavescens (Shaw, 1800 ha experimentado un crecimiento continuo en las ultimas décadas en las costas de la Patagonia Argentina. Sin embargo, poco se conoce sobre la ecología trófica de la especie en el área. El objetivo de este estudio fue analizar los hábitos alimentarios de O. flavescens a partir de 91 fecas colectadas en la provincia de Río Negro, durante el invierno y la primavera del 2005. Los peces estuvieron presentes en el 96% de las fecas que contenían remanentes presas, seguidos por los cefalópodos (26%. Raneya brasiliensis (Kaup, 1856 fue la especie mas frecuente y abundante ocurriendo en el 58.6% de las muestras y constituyendo casi el 50% de los peces predados. Le siguieron en importancia Porichthys porosissimus (Cuvier, 1829 y

[Central diabetes insipidus: diagnostic difficulties].

Science.gov (United States)

Matoussi, N; Aissa, K; Fitouri, Z; Hajji, M; Makni, S; Bellagha, I; Ben Becher, S

2008-06-01

Central diabetes insipidus is rare in children. Characteristic features include polyuria and polydipsia due to arginine vasopressin deficiency. The differential diagnosis of polyuric states may be difficult. Etiologic diagnosis of central diabetes insipidus may be an equally difficult task. To specify the difficulties encountered in the diagnosis of central diabetes insipidus and to point out features of the etiologic work-up and of long-term follow-up of children with idiopathic central diabetes insipidus. A retrospective study of 12 children admitted with a polyuria/polydipsia syndrome to the pediatric - consultation and emergency unit of the children's hospital of Tunis between 1988 and 2005. Children with acquired nephrogenic central diabetes insipidus were excluded. Fourteen-hour fluid restriction test and/or desmopressin test were used without plasma vasopressin measurement. Eight patients were classified as having central diabetes insipidus, which was severe in seven children and partial in one girl. One patient was classified as having primary polydipsia. The diagnosis remains unclear in three patients. The etiological work-up in eight patients with central diabetes insipidus enabled the identification of Langerhan's-cell histiocytosis in two patients and neurosurgical trauma in one. The cause was considered idiopathic in five patients. The median follow-up of the five patients with idiopathic central diabetes insipidus was five years two months plus or minus six years seven months (range five months, 14.5 years). During this follow-up, neither brain magnetic resonance imaging scans findings nor anterior pituitary function have changed. Fluid restriction and desmopressin tests did not enable an accurate distinction between partial diabetes insipidus and primary polydipsia. Regular surveillance is warranted in patients with idiopathic central diabetes insipidus to identify potential etiologies.

Gangs in Central America

National Research Council Canada - National Science Library

Ribando, Clare

2005-01-01

... activities of Central American gangs. Citizens in several Central American countries have identified crime and gang violence among the top issues of popular concern, and Honduras and El Salvador have recently enacted tough anti-gang legislation...

Influence of arm movement on central tip location of peripherally inserted central catheters (PICCs)

International Nuclear Information System (INIS)

Connolly, Bairbre; Amaral, Joao; Walsh, Sharon; Temple, Michael; Chait, Peter; Stephens, Derek

2006-01-01

PICCs are increasingly employed in children. Some of their risks relate to the location of the central tip. Despite care when placing lines, they sometimes move. To evaluate the influence of arm movement on the central tip location of PICCs placed in children. The central tip location of PICCs was studied in 85 children, with the arm placed in six positions. The variables of side, vein, site and arm position were examined to measure the direction and range of tip movement. The side, site or vein used did not influence the range of movement of the central tip. Change in position of the arm had a significant influence on the central tip location, moving it an average of 2.2 rib spaces, a maximum of 3.5 ribs. Elbow bending and adduction of the arm caused the central tip to move deeper into the chest, compared to when the arm was straight and abducted 90 . Arm position is the significant variable influencing PICC movement. Side, site and vein do not influence the range of movement significantly. Most PICCs descend deeper into the chest with arm adduction and elbow bending. (orig.)

Central presbycusis: an emerging view.

Science.gov (United States)

Gates, George A

2012-07-01

Age-related dysfunction of the central auditory system (central presbycusis) is common but rarely looked for by those who provide aural rehabilitation. Patients who complain of difficulty hearing in noise--the key symptom of central presbycusis--are generally disadvantaged with conventional rehabilitation. This symptom should be documented with commercially available speech-in-noise tests, which use materials that are uncomplicated to administer. Those patients who perform poorly on such tests should have a customized rehabilitation program aimed at optimizing their remaining communication abilities. Otolaryngologists who provide auditory rehabilitation may wish to consider expanding their practices to meet the communication needs of older patients with central presbycusis. Central presbycusis is an emerging area for basic and clinical research in auditory neurotology, particularly in the relation of cognitive dysfunction to impaired auditory processing.

Central Diffraction in ALICE

CERN Document Server

Schicker, R

2012-01-01

The ALICE experiment at the Large Hadron Collider (LHC) at CERN consists of a central barrel, a muon spectrometer and of additional detectors for trigger and event classification purposes. The low transverse momentum threshold of the central barrel gives ALICE a unique opportunity to study the low mass sector of central production at the LHC. I will report on first analysis results of meson production in double gap events in minimum-bias proton-proton collisions at sqrt{s} = 7 TeV, and will describe a dedicated double gap trigger for future data taking.

Central control of body temperature.

Science.gov (United States)

Morrison, Shaun F

2016-01-01

Central neural circuits orchestrate the behavioral and autonomic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response and behavioral states and in response to declining energy homeostasis. This review summarizes the central nervous system circuit mechanisms controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction regulating heat loss and shivering and brown adipose tissue for thermogenesis. The activation of these thermoeffectors is regulated by parallel but distinct efferent pathways within the central nervous system that share a common peripheral thermal sensory input. The model for the neural circuit mechanism underlying central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation, for elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation, and for the discovery of novel therapeutic approaches to modulating body temperature and energy homeostasis.

Imprints of Climate Signals in a 204 Year δ18O Tree-Ring Record of Nothofagus pumilio From Perito Moreno Glacier, Southern Patagonia (50°S

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Jussi Grießinger

2018-04-01

Full Text Available A 204 year-long record of δ18O in tree-ring cellulose of southern beech (Nothofagus pumilio from a site near Perito Moreno Glacier (50°S in Southern Patagonia was established to assess its potential for a climate reconstruction. The annually resolved oxygen isotope chronology is built out of seven individual tree-ring δ18O series with a significant mean inter-series correlation (r = 0.61 and is the first of its kind located in Southern America south of 50°S. Over a common period from 1960 to 2013 of available stationary and high-resolution gridded CRU TS v. 4.01 data, the δ18O chronology exhibits a strong sensitivity toward hydroclimatic as well as temperature parameters as revealed by correlation analyses. Among these, positive correlations with maximum temperature in the first part of the summer season (CRU rONDJ = 0.51, p < 0.01 and negative correlations with precipitation in the latter half of the vegetation period (CRU rONDJ = −0.54, p < 0.01 show the highest sensitivities. A strong supra-regional influence of the Southern Annular Mode (SAM is clearly recorded in this chronology as indicated by significant positive correlations during the vegetation period (rONDJ = 0.62, p < 0.01. This indicates that the presented δ18O-chronology shows great promise to reconstruct the influence and variability of the SAM within the last two centuries in southern South America. The modulation of positive and negative anomalies within this series can be interlinked to changes in moisture source origin as revealed by backward trajectory modeling. Additionally, these anomalies can be directly associated to positive or negative phases of the Antarctic Oscillation Index (AAOI and therefore the strength of the Westerlies. Aligned by the analysis on the influence of different main weather types on the δ18O chronology it is shown that such time-series hold the potential to additionally capture their respective influence and change during the last centuries.

A global central banker competency model

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David W. Brits

2014-07-01

Full Text Available Orientation: No comprehensive, integrated competency model exists for central bankers. Due to the importance of central banks in the context of the ongoing global financial crisis, it was deemed necessary to design and validate such a model. Research purpose: To craft and validate a comprehensive, integrated global central banker competency model (GCBCM and to assess whether central banks using the GCBCM for training have a higher global influence. Motivation for the study: Limited consensus exists globally about what constitutes a ‘competent’ central banker. A quantitatively validated GCBCM would make a significant contribution to enhancing central banker effectiveness, and also provide a solid foundation for effective people management. Research approach, design and method: A blended quantitative and qualitative research approach was taken. Two sets of hypotheses were tested regarding the relationships between the GCBCM and the training offered, using the model on the one hand, and a central bank’s global influence on the other. Main findings: The GCBCM was generally accepted across all participating central banks globally, although some differences were found between central banks with higher and lower global influence. The actual training offered by central banks in terms of the model, however, is generally limited to technical-functional skills. The GCBCM is therefore at present predominantly aspirational. Significant differences were found regarding the training offered. Practical/managerial implications: By adopting the GCBCM, central banks would be able to develop organisation-specific competency models in order to enhance their organisational capabilities and play their increasingly important global role more effectively. Contribution: A generic conceptual framework for the crafting of a competency model with evaluation criteria was developed. A GCBCM was quantitatively validated.

CENTRAL BANKING IN THE NEW ERA

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Bilal Bagis

2017-12-01

Full Text Available This paper analyzes the evolution of central banking, and in particular the American experience of central banking. It provides projections for the future of central banking in the new era of post 2008. The paper initially demonstrates recent improvements in the financial and banking sectors, regulations and different measures of monetary and financial rules both in the USA and the rest of the advanced economies. Then, it claims institutions, such as central banks, will gain new objectives and more significance in this new era and thus will be given new roles, over time and along with the improvements and deepening in the financial system. The paper argues centuries long central bank evolution is not complete yet and that more objectives should be expected to come forward. In that line, there is need for a shift in the conventional policy measures. New trends in central banking such as the helicopter money, popular nominal GDP targeting regime and the retro developmental central banking are all critically analyzed. The paper provides a breakdown of financial development and central banking activities in a historical context and provides a rationale and a new basis for possible future innovations.

Simulation of Dry Matter Productivity and Water Dynamics in a Chilean Patagonian Range Simulación de la Productividad de Materia Seca y Dinámica del Agua en Praderas de la Patagonia Chilena

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Giorgio Castellaro G

2010-09-01

Full Text Available This paper describes a simulation model combining the main components of water balance and growth of perennial grassland steppe in Chilean Patagonia, to estimate long-term annual production (Yr, kg ha-1 and sheep carrying capacity (GC, sheep equivalent [EO] ha-1. The model is based on climate-water balance relationships, where the basic process is evapotranspiration. The model calculates Yr depending on the accumulation of transpiration and the water use efficiency from the time of growth initiation until the grassland accumulates the maximum amount of dry matter (DM. Depending on Yr, the DM requirement of EO, the proper use factor of grassland and a slope correction factor, a range site GC is calculated. Simulations were performed using actual climate data sets of eight growing seasons at Kampenaike (52º41' S; 70°54'W; 12 m.a.s.l. and a long-term simulation in the same location, using a stochastic weather variables generator. Through the model it was possible to estimate the water loss associated with the components of water balance and estimate the restriction imposed by water deficit on Yr. By simulating many years, it was possible to establish a normal distribution of GC with 0.629 EO ha-1 yr-1, associated with 80% probability of being exceeded, which is lower than values reported in field assessments. This method calculates GC with a conservational approach, taking into account soil and climatic variability in semiarid ecosystems.Se describe un modelo de simulación para pastizales esteparios de la Patagonia chilena, que estima a largo plazo los principales componentes del balance hídrico, la producción anual de MS (Yr, kg ha-1 y la capacidad de carga ovina (GC, equivalente ovino [EO] ha-1 de éstos. El modelo se basa en la relación clima-balance hídrico, siendo el proceso básico la evapotranspiración. Yr es función de la acumulación de transpiración durante la temporada de crecimiento y de la eficiencia del uso del agua. La GC

Actual versus perceived central bank transparency: the case of the European Central Bank

NARCIS (Netherlands)

van der Cruijsen, C.; Eijffinger, S.

2008-01-01

Central banks have become more and more transparent about their monetary policy making process. In the central bank transparency literature the distinction between actual and perceived transparency is often lacking. However, as perceptions are crucial for the actions of economic agents this

Optimal Central Bank Transparency

NARCIS (Netherlands)

van der Cruijsen, C.A.B.; Eijffinger, S.C.W.; Hoogduin, L.H.

2008-01-01

Should central banks increase their degree of transparency any further? We show that there is likely to be an optimal intermediate degree of central bank transparency. Up to this optimum more transparency is desirable: it improves the quality of private sector inflation forecasts. But beyond the

Optimal central bank transparency

NARCIS (Netherlands)

van der Cruijsen, C.A.B.; Eijffinger, S.C.W.; Hoogduin, L.

2008-01-01

Should central banks increase their degree of transparency any further? We show that there is likely to be an optimal intermediate degree of central bank transparency. Up to this optimum more transparency is desirable: it improves the quality of private sector inflation forecasts. But beyond the

Optimal central bank transparency

NARCIS (Netherlands)

van der Cruijsen, C.A.B.; Eijffinger, S.C.W.; Hoogduin, L.H.

2010-01-01

Should central banks increase their degree of transparency any further? We show that there is likely to be an optimal intermediate degree of central bank transparency. Up to this optimum more transparency is desirable: it improves the quality of private sector inflation forecasts. But beyond the

Approximating centrality in evolving graphs: toward sublinearity

Science.gov (United States)

Priest, Benjamin W.; Cybenko, George

2017-05-01

The identification of important nodes is a ubiquitous problem in the analysis of social networks. Centrality indices (such as degree centrality, closeness centrality, betweenness centrality, PageRank, and others) are used across many domains to accomplish this task. However, the computation of such indices is expensive on large graphs. Moreover, evolving graphs are becoming increasingly important in many applications. It is therefore desirable to develop on-line algorithms that can approximate centrality measures using memory sublinear in the size of the graph. We discuss the challenges facing the semi-streaming computation of many centrality indices. In particular, we apply recent advances in the streaming and sketching literature to provide a preliminary streaming approximation algorithm for degree centrality utilizing CountSketch and a multi-pass semi-streaming approximation algorithm for closeness centrality leveraging a spanner obtained through iteratively sketching the vertex-edge adjacency matrix. We also discuss possible ways forward for approximating betweenness centrality, as well as spectral measures of centrality. We provide a preliminary result using sketched low-rank approximations to approximate the output of the HITS algorithm.

Políticas económicas, financieras e impositivas del gobierno del Chubut y la Municipalidad de Esquel hacia las Pymes de Esquel (Chubut)

OpenAIRE

Colabelli, Diego Emilio

2014-01-01

Las pequeñas y medianas empresas, (Pymes), tienen particular importancia para las economías nacional y regional, no solo por sus aportaciones a la producción y distribución de bienes y servicios, sino también por la flexibilidad de adaptarse a los cambios tecnológicos y el gran potencial de generación de empleos. Representan un excelente medio para impulsar el desarrollo económico y una mejor distribución de la riqueza. Sin embargo, las Pymes tienen algunas dificultades, d...

Central venous pressure monitoring via peripherally or centrally inserted central catheters: a systematic review and meta-analysis.

Science.gov (United States)

Sanfilippo, Filippo; Noto, Alberto; Martucci, Gennaro; Farbo, Marco; Burgio, Gaetano; Biasucci, Daniele G

2017-07-14

The central venous pressure (CVP) is the most commonly used static marker of preload for guiding fluid therapy in critically ill patients, though its usefulness remains controversial. Centrally inserted central catheters (CICCs) are the gold-standard devices for CVP monitoring but peripherally inserted central catheters (PICCs) may represent a valid alternative. We undertook a systematic review and meta-analysis with the aim to investigate whether the difference between PICC- and CICC-measured CVP is not significant. We searched for clinical studies published in PubMed and EMBASE databases from inception until December 21st 2016. We included studies providing data on paired and simultaneous CVP measurement from PICCs and CICCs. We conducted two analyses on the values of CVP, the first one according to the total number of CVP assessments, the second one considering the number of patients recruited. Four studies matched the inclusion criteria, but only three of them provided data for the meta-analyses. Both analyses showed non-significant differences between PICC-measured and CICC-measured CVP: 1489 paired simultaneous CVP assessments (MD 0.16, 95%CI -0.14, 0.45, p = 0.30) on a total of 57 patients (MD 0.22, 95%CI -1.46, 1.91, p = 0.80). Both analyses showed no heterogeneity (I2 = 0%). Available evidence supports that CVP monitoring with PICCs is accurate and reproduces similar values to those obtained from CICCs. The possibility to monitor CVP should not be used among clinical criteria for preferring a CICC over a PICC line.

Controlling centrality in complex networks

Science.gov (United States)

Nicosia, V.; Criado, R.; Romance, M.; Russo, G.; Latora, V.

2012-01-01

Spectral centrality measures allow to identify influential individuals in social groups, to rank Web pages by popularity, and even to determine the impact of scientific researches. The centrality score of a node within a network crucially depends on the entire pattern of connections, so that the usual approach is to compute node centralities once the network structure is assigned. We face here with the inverse problem, that is, we study how to modify the centrality scores of the nodes by acting on the structure of a given network. We show that there exist particular subsets of nodes, called controlling sets, which can assign any prescribed set of centrality values to all the nodes of a graph, by cooperatively tuning the weights of their out-going links. We found that many large networks from the real world have surprisingly small controlling sets, containing even less than 5 – 10% of the nodes. PMID:22355732

Regional drought in the southern of South America: physical aspects Seca regional no sul da América do Sul: aspectos físicos

Directory of Open Access Journals (Sweden)

Juan Leonidas Minetti

2010-03-01

Full Text Available From the indices of monthly and annual climatic drought in six regions in southern South America and their associations with seventeen predictors, the probable physical causes of droughts are analyzed. These indices are used in operational climate monitoring and describe the atmospheric temperature and sea surface temperature (SST near South America. Subtropical anticyclone activity over both coasts of South America is one of the main predictors, together with its interaction with the continental depression and SST at the coast of Brazil. The highest predictability concentrates in November-December-May and the lowest in March, June and August. In the sub regional scale, the main predictors respond to atmospheric pressure anomalies in the Atlantic Ocean for Argentinean Northwest (NOA, SST in the Brazilian coast for Argentinean Northeast (NEA, anticyclonic conditions over the Pacific and Atlantic for the Central West (CO, the latter and their interaction with the continental depression for Humid Pampa (PH, anticyclonic activity over the Pacific for the Patagonia (PAT and trans cordillera circulation for Central Chile and Comahue (CHI.As causas físicas prováveis das secas em seis regiões no sul da América do Sul são analisadas, através de índices da seca climática mensal e em suas associações com dezessete preditores. Esses indices são usados no monitoramento operacional do clima, e descrevem a temperatura atmosférica e a temperatura de superfície do mar (TSM perto de América do Sul. A atividade do anticiclone subtropical sobre ambas as costas de América do Sul é um dos preditores principais, junto com sua interação com a depressão continental e a SST na costa do Brasil. A previsibilidade mais elevada concentra-se nos meses Novembro-Dezembro-Maio e a mais baixa, em março, junho e agosto. Na escala regional secundária, os principais preditores respondem às anomalias da pressão atmosférica sobre o Oceano Atlântico para

EIGENVECTOR-BASED CENTRALITY MEASURES FOR TEMPORAL NETWORKS*

Science.gov (United States)

TAYLOR, DANE; MYERS, SEAN A.; CLAUSET, AARON; PORTER, MASON A.; MUCHA, PETER J.

2017-01-01

Numerous centrality measures have been developed to quantify the importances of nodes in time-independent networks, and many of them can be expressed as the leading eigenvector of some matrix. With the increasing availability of network data that changes in time, it is important to extend such eigenvector-based centrality measures to time-dependent networks. In this paper, we introduce a principled generalization of network centrality measures that is valid for any eigenvector-based centrality. We consider a temporal network with N nodes as a sequence of T layers that describe the network during different time windows, and we couple centrality matrices for the layers into a supra-centrality matrix of size NT × NT whose dominant eigenvector gives the centrality of each node i at each time t. We refer to this eigenvector and its components as a joint centrality, as it reflects the importances of both the node i and the time layer t. We also introduce the concepts of marginal and conditional centralities, which facilitate the study of centrality trajectories over time. We find that the strength of coupling between layers is important for determining multiscale properties of centrality, such as localization phenomena and the time scale of centrality changes. In the strong-coupling regime, we derive expressions for time-averaged centralities, which are given by the zeroth-order terms of a singular perturbation expansion. We also study first-order terms to obtain first-order-mover scores, which concisely describe the magnitude of nodes’ centrality changes over time. As examples, we apply our method to three empirical temporal networks: the United States Ph.D. exchange in mathematics, costarring relationships among top-billed actors during the Golden Age of Hollywood, and citations of decisions from the United States Supreme Court. PMID:29046619

Central gain control in tinnitus and hyperacusis

Directory of Open Access Journals (Sweden)

Benjamin D Auerbach

2014-10-01

Full Text Available Sensorineural hearing loss induced by noise or ototoxic drug exposure reduces the neural activity transmitted from the cochlea to the central auditory system. Despite a reduced cochlear output, neural activity from more central auditory structures is paradoxically enhanced at suprathreshold intensities. This compensatory increase in the central auditory activity in response to the loss of sensory input is referred to as central gain enhancement. Enhanced central gain is hypothesized to be a potential mechanism that gives rise to hyperacusis and tinnitus, two debilitating auditory perceptual disorders that afflict millions of individuals. This review will examine the evidence for gain enhancement in the central auditory system in response to cochlear damage. Further, it will address the potential cellular and molecular mechanisms underlying this enhancement and discuss the contribution of central gain enhancement to tinnitus and hyperacusis. Current evidence suggests that multiple mechanisms with distinct temporal and spectral profiles are likely to contribute to central gain enhancement. Dissecting the contributions of these different mechanisms at different levels of the central auditory system is essential for elucidating the role of central gain enhancement in tinnitus and hyperacusis and, most importantly, the development of novel treatments for these disorders.

Central Gain Control in Tinnitus and Hyperacusis

Science.gov (United States)

Auerbach, Benjamin D.; Rodrigues, Paulo V.; Salvi, Richard J.

2014-01-01

Sensorineural hearing loss induced by noise or ototoxic drug exposure reduces the neural activity transmitted from the cochlea to the central auditory system. Despite a reduced cochlear output, neural activity from more central auditory structures is paradoxically enhanced at suprathreshold intensities. This compensatory increase in the central auditory activity in response to the loss of sensory input is referred to as central gain enhancement. Enhanced central gain is hypothesized to be a potential mechanism that gives rise to hyperacusis and tinnitus, two debilitating auditory perceptual disorders that afflict millions of individuals. This review will examine the evidence for gain enhancement in the central auditory system in response to cochlear damage. Further, it will address the potential cellular and molecular mechanisms underlying this enhancement and discuss the contribution of central gain enhancement to tinnitus and hyperacusis. Current evidence suggests that multiple mechanisms with distinct temporal and spectral profiles are likely to contribute to central gain enhancement. Dissecting the contributions of these different mechanisms at different levels of the central auditory system is essential for elucidating the role of central gain enhancement in tinnitus and hyperacusis and, most importantly, the development of novel treatments for these disorders. PMID:25386157

Granuloma central de células gigantes Giant cells central granuloma

Directory of Open Access Journals (Sweden)

Ayelén María Portelles Massó

2011-03-01

Full Text Available El granuloma reparativo central de células gigantes es una lesión proliferativa no neoplásica de etiología desconocida. Se presenta un paciente masculino de 40 años de edad, portador de prótesis parcial superior. Fue remitido al Servicio de Cirugía Maxilofacial del Hospital "V. I. Lenin" por presentar aumento de volumen en reborde alveolar superior, de color rojo grisáceo y que provocaba expansión de corticales óseas. Una vez analizados los exámenes clínicos, radiográficos e histopatológicos se diagnosticó un granuloma reparativo central de células gigantes Se realizó exéresis quirúrgica de la lesión y extracción de dientes adyacentes con una evolución satisfactoria sin señales de recidivas luego de tres años del tratamiento. El granuloma reparativo central de células gigantes se presentó como respuesta a un trauma. La correcta interpretación de los datos clínicos, radiográficos e histopatológicos nos permitió llegar al correcto diagnóstico y plan de tratamiento.Giant-cell central reparative granuloma is non neoplastic proliferative lesion of unknown etiology. We report a 40 years old male patient who was admitted at the Maxillofacial Service of the "V. I. Lenin" Hospital. The patient had partial upper prosthesis and was complaining of red-grey volume increase lesion in upper alveolar ridge which led to the expansion of cortical bone. Having analyzed clinical, radiographic and histopathological findings the case was concluded as a giant-cell central reparative granuloma. Surgical exeresis and adjunct tooth extraction were done. After three years of treatment, satisfactory follow up without recurrence is reported.

AAPT Diagnostic Criteria for Central Neuropathic Pain

DEFF Research Database (Denmark)

Widerstrom-Noga, Eva; Loeser, John D.; Jensen, Troels Staehelin

2017-01-01

Central neuropathic pain, which is pain caused by a lesion or disease of the central somatosensory nervous system, is a serious consequence of spinal cord injury, stroke, multiple sclerosis, and other conditions affecting the central nervous system. A collaborative effort between the Analgesic....... This article focuses on central neuropathic pain associated with spinal cord injury, stroke, and multiple sclerosis, but the AAPT framework can be extended to central pain due to other causes such as traumatic brain injury. The classification of central neuropathic pain is organized according to the AAPT...

Idiopathic central diabetes Insipidus.

Science.gov (United States)

Grace, Mary; Balachandran, Venu; Menon, Sooraj

2011-10-01

Idiopathic central diabetes insipidus (CDI) is a rare disorder characterized clinically by polyuria and polydipsia, and an abnormal urinary concentration without any identified etiology. We report a case of central diabetes insipidus in a 60-year-old lady in the absence of secondary causes like trauma, infection, and infiltrative disorders of brain.

Procesamiento integral de las especies patagónicas de cangrejos marinos de valor comercial Ovalipes trimaculatus y Platyxanthus patagonicus

OpenAIRE

Dima, Jimena Bernadette

2013-01-01

La industria pesquera de la Provincia de Chubut se ha desarrollado con la captura y el procesamiento de un conjunto tradicional de peces y mariscos. En los últimos años, y como consecuencia de la disminución de los recursos pesqueros tradicionales, ha surgido interés desde el sector por recursos con posibilidades de mercado aún no aprovechadas, tales como, las almejas: Panopea y Navaja (Barón y col, 2004; Lasta y col, 1996), el alga Undaria pinnatifida (Casas y Piritz, 1996) y algunos cangrej...

Repensar la construcción de cartografías sociales: el conflicto como contexto en los procesos de subjetivación política

OpenAIRE

Sabatella, María Emilia

2018-01-01

Este capítulo busca reflexionar acerca de la construcción de relacionalidades históricas (vínculos parentales, vecinales, alianzas políticas) en la definición del espacio social en contextos de lucha a partir de un caso situado: el de las comunidades mapuche Cañio y Ñiripil, asentadas en el cerro León de la Aldea Buenos Aires Chico, provincia de Chubut, Argentina. Desde el año 2010, estas comunidades atraviesan un proceso de conflicto territorial con el municipio y empresarios de la localidad...

Central Diabetes Insipidus, Central Hypothyroidism, Renal Tubular ...

African Journals Online (AJOL)

readmitted to the hospital because of jaundice and failure to thrive, for which he was investigated and diagnosed to have central congenital hypothyroidism. Shortly thereafter, he was admitted to our institute with a history of vomiting, decreased oral intake, polyuria, and dehydration having lasted 5 days. He was investigated ...

Central bank independence and inflation revisited

NARCIS (Netherlands)

Klomp, Jeroen; de Haan, Jakob

We re-examine the relationship between central bank independence (CBI), proxied by the central bank governor's turnover rate and an indicator based on central bank laws in place, and inflation using a random coefficient model with the Hildreth-Houck estimator for more than 100 countries in the

Central bank independence and inflation revisited

NARCIS (Netherlands)

Klomp, J.G.; Haan, de J.

2010-01-01

We re-examine the relationship between central bank independence (CBI), proxied by the central bank governor's turnover rate and an indicator based on central bank laws in place, and inflation using a random coefficient model with the Hildreth-Houck estimator for more than 100 countries in the

Performance contracting in central government in Denmark

DEFF Research Database (Denmark)

Kristiansen, Mads Bøge

2015-01-01

) are observed across central government agencies, when the content of the performance contracts is compared. This makes it interesting to examine how variation in the content of the performance contracts across agencies can be explained? Based on a broad theoretical framework in which variation......This paper looks into performance contracting in Danish central government. Management by Objectives and Results (MBOR) was adopted in central government in Denmark during the 1980s and early 1990s. In 1991, performance contracts between parent ministries and their agencies were introduced...... in Danish central government. Since their introduction, performance contracts have become central elements in the steering and management of agencies in central government in Denmark, and today they are nearly universally adopted in central government. In Denmark, the Ministry of Finance is responsible...

Central Bank independence

Directory of Open Access Journals (Sweden)

Vasile DEDU

2012-08-01

Full Text Available In this paper we present the key aspects regarding central bank’s independence. Most economists consider that the factor which positively influences the efficiency of monetary policy measures is the high independence of the central bank. We determined that the National Bank of Romania (NBR has a high degree of independence. NBR has both goal and instrument independence. We also consider that the hike of NBR’s independence played an important role in the significant disinflation process, as headline inflation dropped inside the targeted band of 3% ± 1 percentage point recently.

Central Venous Access

International Nuclear Information System (INIS)

Ganeshan, Arul; Warakaulle, Dinuke R.; Uberoi, Raman

2007-01-01

Central venous access plays an important role in the management of an ever-increasing population of patients ranging from those that are critically ill to patients with difficult clinical access. Interventional radiologists are key in delivering this service and should be familiar with the wide range of techniques and catheters now available to them. A comprehensive description of these catheters with regard to indications, technical aspects of catheterization, success rates, and associated early and late complications, as well as a review of various published guidelines on central venous catheter insertion are given in this article

Risk Premium and Central Bank Intervention

OpenAIRE

Pinar Ozlu

2006-01-01

This study examines the relation between the risk premium and central bank intervention. Forward rates are calculated for the Turkish Lira-USD exchange market and then the effect of central bank intervention on the risk premium is estimated. Using high quality daily intervention data from the Central Bank of Turkey as well as implied forward rates, an MA (21)-GARCH (1,1) model is estimated. Both purchases and sales of US dollars by the Central Bank of Turkey appear to have no effect on the si...

Big Data and central banks

OpenAIRE

David Bholat

2015-01-01

This commentary recaps a Centre for Central Banking Studies event held at the Bank of England on 2–3 July 2014. The article covers three main points. First, it situates the Centre for Central Banking Studies event within the context of the Bank’s Strategic Plan and initiatives. Second, it summarises and reflects on major themes from the event. Third, the article links central banks’ emerging interest in Big Data approaches with their broader uptake by other economic agents.

Big Data and central banks

Directory of Open Access Journals (Sweden)

David Bholat

2015-04-01

Full Text Available This commentary recaps a Centre for Central Banking Studies event held at the Bank of England on 2–3 July 2014. The article covers three main points. First, it situates the Centre for Central Banking Studies event within the context of the Bank’s Strategic Plan and initiatives. Second, it summarises and reflects on major themes from the event. Third, the article links central banks’ emerging interest in Big Data approaches with their broader uptake by other economic agents.

Central Bank Independence, Centralization of Wage Bargaining, Inflation and Unemployment - Theory and Some Evidence

NARCIS (Netherlands)

Cukierman, A.; Lippi, F.

1998-01-01

This paper proposes a conceptual framework to investigate the effects of central bank independence, of the degree of centralization of wage bargaining and of the interaction between those institutional variables, on real wages, unemployment and inflation, in a framework in which unions are averse to

Longer and less overlapping food webs in anthropogenically disturbed marine ecosystems: confirmations from the past.

Directory of Open Access Journals (Sweden)

Fabiana Saporiti

Full Text Available The human exploitation of marine resources is characterised by the preferential removal of the largest species. Although this is expected to modify the structure of food webs, we have a relatively poor understanding of the potential consequences of such alteration. Here, we take advantage of a collection of ancient consumer tissues, using stable isotope analysis and SIBER to assess changes in the structure of coastal marine food webs in the South-western Atlantic through the second half of the Holocene as a result of the sequential exploitation of marine resources by hunter-gatherers, western sealers and modern fishermen. Samples were collected from shell middens and museums. Shells of both modern and archaeological intertidal herbivorous molluscs were used to reconstruct changes in the stable isotopic baseline, while modern and archaeological bones of the South American sea lion Otaria flavescens, South American fur seal Arctocephalus australis and Magellanic penguin Spheniscus magellanicus were used to analyse changes in the structure of the community of top predators. We found that ancient food webs were shorter, more redundant and more overlapping than current ones, both in northern-central Patagonia and southern Patagonia. These surprising results may be best explained by the huge impact of western sealing on pinnipeds during the fur trade period, rather than the impact of fishing on fish populations. As a consequence, the populations of pinnipeds at the end of the sealing period were likely well below the ecosystem's carrying capacity, which resulted in a release of intraspecific competition and a shift towards larger and higher trophic level prey. This in turn led to longer and less overlapping food webs.

Central Asia's raging waters the prospects of water conflict in Central Asia

OpenAIRE

Hartman, William B.

2007-01-01

This thesis examines the prospects of conflict caused by water scarcity in Central Asia. The thesis analyzes the three most recent political eras of Central Asia, Tsarist Russia, the Soviet Union and independence, utilizing indicators of water tensions including: water quality, water quantity, the management of water for multiple uses, the political divisions and geopolitical setting, state institutions and national water ethos. Although water is not likely to be the sole cause of a majo...

Central blood pressure and chronic kidney disease

Science.gov (United States)

Ohno, Yoichi; Kanno, Yoshihiko; Takenaka, Tsuneo

2016-01-01

In this review, we focused on the relationship between central blood pressure and chronic kidney diseases (CKD). Wave reflection is a major mechanism that determines central blood pressure in patients with CKD. Recent medical technology advances have enabled non-invasive central blood pressure measurements. Clinical trials have demonstrated that compared with brachial blood pressure, central blood pressure is a stronger risk factor for cardiovascular (CV) and renal diseases. CKD is characterized by a diminished renal autoregulatory ability, an augmented direct transmission of systemic blood pressure to glomeruli, and an increase in proteinuria. Any elevation in central blood pressure accelerates CKD progression. In the kidney, interstitial inflammation induces oxidative stress to handle proteinuria. Oxidative stress facilitates atherogenesis, increases arterial stiffness and central blood pressure, and worsens the CV prognosis in patients with CKD. A vicious cycle exists between CKD and central blood pressure. To stop this cycle, vasodilator antihypertensive drugs and statins can reduce central blood pressure and oxidative stress. Even in early-stage CKD, mineral and bone disorders (MBD) may develop. MBD promotes oxidative stress, arteriosclerosis, and elevated central blood pressure in patients with CKD. Early intervention or prevention seems necessary to maintain vascular health in patients with CKD. PMID:26788468

Payments and Central Bank Policy

DEFF Research Database (Denmark)

Korsgaard, Søren

This thesis consists of three chapters. The rst, "Paying for Payments", examines the role of interchange fees in payment card networks. The second, "Bank Liquidity and the Interbank Market" (co-authored with Mikael Reimer Jensen), investigates how banks' liquidity holdings at the central bank a ect...... outcomes in the money market. The third, "Collateralized Lending and Central Bank Collateral Policy", considers the emergence of credit constraints under collateralized lending, and how central banks use collateral policy to mitigate these constraints. While the chapters can be read independently......, they share common themes. Each chapter is concerned with payments in one way or another, each is concerned with the e ciency of market outcomes, and, to the extent that there is scope for improving these outcomes, each discusses the appropriate role for policy, in particular central bank policy....

Do central bank law reforms affect the term in office of central bank governors?

NARCIS (Netherlands)

Klomp, J.G.; de Haan, J.

In this paper we confirm the hypothesis that central bank independence reforms reduce the likelihood that a central bank governor will be replaced. However, the strength of this effect depends on the rule of law and the degree of political polarization. (c) 2009 Elsevier B.V. All rights reserved.

Current status of laparoscopic central pancreatectomy

Directory of Open Access Journals (Sweden)

CAO Yang

2017-04-01

Full Text Available Central pancreatectomy is an ideal surgical procedure for the treatment of benign or low-grade malignant tumors in the pancreatic neck or the proximal body of the pancreas, and it can preserve more normal pancreatic tissue in order to reduce the incidence of endocrine and exocrine insufficiency after surgery. Although some clinical studies have demonstrated the feasibility and safety of this procedure, laparoscopic central pancreatectomy was technically challenging with a few number of cases. This article reviews the current status of laparoscopic central pancreatectomy and introduces our clinical experience of laparoscopic central pancreatectomy and pancreaticojejunostomy.

Central cell confinement in MFTF-B

International Nuclear Information System (INIS)

Jong, R.A.

1981-01-01

The point code TANDEM has been used to survey the range of plasma parameters which can be attained in MFTF-B. The code solves for the electron and ion densities and temperatures in the central cell, yin-yang, barrier, and A-cell regions as well as the plasma potential in each region. In these studies, the A-cell sloshing ion beams were fixed while the neutral beams in the yin-yang and central cell, the gas feed in the central cell, and the applied ECRH power β, central cell ion density and temperature, and the confining potential are discussed

Central Hypothyroidism in Miniature Schnauzers

NARCIS (Netherlands)

Voorbij, Annemarie M W Y; Leegwater, Peter A J; Buijtels, Jenny J C W M; Daminet, Sylvie; Kooistra, Hans S

2016-01-01

BACKGROUND: Primary hypothyroidism is a common endocrinopathy in dogs. In contrast, central hypothyroidism is rare in this species. OBJECTIVES: The objective of this article is to describe the occurrence and clinical presentation of central hypothyroidism in Miniature Schnauzers. Additionally, the

Complications of central venous stenosis due to permanent central venous catheters in children on hemodialysis.

Science.gov (United States)

Rinat, Choni; Ben-Shalom, Efrat; Becker-Cohen, Rachel; Feinstein, Sofia; Frishberg, Yaacov

2014-11-01

Central venous catheters are frequently used as access for hemodialysis (HD) in children. One of the known complications is central venous stenosis. Although this complication is not rare, it is often asymptomatic and therefore unacknowledged. Superior vena cava (SVC) stenosis is obviously suspected in the presence of upper body edema, but several other signs and symptoms are often unrecognized as being part of this syndrome. We describe four patients with various manifestations of central venous stenosis and SVC syndrome. These sometimes life- or organ-threatening conditions include obstructive sleep apnea, unresolving stridor, increased intracranial pressure, increased intraocular pressure, right-sided pleural effusion, protein-losing enteropathy and lymphadenopathy. The temporal relationship of these complications associated with the use of central venous catheters and documentation of venous stenosis, together with their resolution after alleviation of high venous pressure, points to a causal role. We suggest pathophysiological mechanisms for the formation of each of these complications. In patients with occlusion of the SVC, various unexpected clinical entities can be caused by high central venous pressure. As often the etiology is not obvious, a high index of suspicion is needed as in some cases prompt alleviation of the high pressure is mandatory.

Environmental pricing of externalities from different sources of electricity generation in Chile

International Nuclear Information System (INIS)

Aravena, Claudia; Hutchinson, W. George; Longo, Alberto

2012-01-01

The rapid increase in electricity demand in Chile means a choice must be made between major investments in renewable or non-renewable sources for additional production. Current projects to develop large dams for hydropower in Chilean Patagonia impose an environmental price by damaging the natural environment. On the other hand, the increased use of fossil fuels entails an environmental price in terms of air pollution and greenhouse gas emissions contributing to climate change. This paper studies the debate on future electricity supply in Chile by investigating the preferences of households for a variety of different sources of electricity generation such as fossil fuels, large hydropower in Chilean Patagonia and other renewable energy sources. Using Double Bounded Dichotomous Choice Contingent Valuation, a novel advanced disclosure method and internal consistency test are used to elicit the willingness to pay for less environmentally damaging sources. Policy results suggest a strong preference for renewable energy sources with higher environmental prices imposed by consumers on electricity generated from fossil fuels than from large dams in Chilean Patagonia. Policy results further suggest the possibility of introducing incentives for renewable energy developments that would be supported by consumers through green tariffs or environmental premiums. Methodological findings suggest that advanced disclosure learning overcomes the problem of internal inconsistency in SB-DB estimates.

Accountability of central banks: aspects and quantification

Directory of Open Access Journals (Sweden)

J. DE HAAN

1999-06-01

Full Text Available The work examines the relationship between central bank independence and accountability. The authors do this by using an indicator for central bank accountability based on the laws of 16 central banks. Central bank accountability is identified as having three distinct features, namely, the explicit definition and ranking of the objectives of monetary policy, the transparency of the actual monetary policy, and the final responsibility to monetary policy.

Colloquium on Central Asia

International Nuclear Information System (INIS)

2005-01-01

This colloquium on Azerbaijan was organized by the direction of international relations of the French Senate and the French center of foreign trade (CFCE). This document gathers the interventions of the participants and the debates with the audience following these interventions. The topics treated concern: - the present day political-economical situation of Central Asia countries (problem of borders, relations with Russia and China); - the economies of Central Asia countries: short term problems and medium-term perspectives; - the relations with the European Union (political, economical, trade and investments, perspectives); - the European energy stakes of Caspian sea (oil and gas reserves, development of hydrocarbon resources, exploitation and transport constraints, stakes for Europe and France); - TotalFinaElf company in Central Asia (Kazakhstan, Azerbaijan, enclavement problem); - the economical impacts of the TRACECA pathway (Transport Corridor Europe Caucasus Asia). (J.S.)

The Naive Central Banker

Directory of Open Access Journals (Sweden)

Marcelo de Carvalho Griebeler

2015-09-01

Full Text Available There has been in some countries a trend of assigning other functions to central banks besides price stability. The most suggested function to be added to monetary authority’s obligations is to pursue economic growth or full employment. In this paper we characterize the behavior and analyse the optimal monetary policy of, what we call, a naive central banker. We describe the naive behavior as one that does face the inflation-unemployment trade-off, but it tries to minimize both variables simultaneously. Our findings, both under discretion and commitment, indicate that the naive central banker delivers lower expected inflation and inflation variance than the benchmark behavior whenever the economy is rigid enough. However, the degree of conservativeness also affects this result, such that the less conservative the naive policymaker, the more rigidity is necessary.

The central nervous system

International Nuclear Information System (INIS)

Holmes, R.A.

1984-01-01

The first section presents a comprehensive evaluation of radionuclide imaging of the central nervous system and provides a comparison of the detection accuracies of radionuclide imaging (RNI) and XCT in certain lesions, realizing that the XCT results may vary when radiocontrast or newer generation XCT scanners are used. Although conventional radionuclide imaging of the central nervous system has experienced no significant changes over the last 7 years except for mild refinements, a new section has been added on positron emission tomography (PET). Most positron radiopharmaceuticals passively cross the intact blood-brain barrier, and their localization has catalyzed renewed interest in our ability to metabolically study and obtain images of the central nervous system. The section on radionuclide cisternography has been rewritten to reflect present day practice and the wider application of XCT in describing conditions affecting the ventricular system

Report of the Central Tracking Group

International Nuclear Information System (INIS)

Cassel, D.G.; Hanson, G.G.

1986-10-01

Issues involved in building a realistic central tracking system for a general-purpose 4π detector for the SSC are addressed. Such a central tracking system must be capable of running at the full design luminosity of 10 33 cm -2 s -1 . Momentum measurement was required in a general-purpose 4π detector. Limitations on charged particle tracking detectors at the SSC imposed by rates and radiation damage are reviewed. Cell occupancy is the dominant constraint, which led us to the conclusion that only small cells, either wires or straw tubes, are suitable for a central tracking system at the SSC. Mechanical problems involved in building a central tracking system of either wires or straw tubes were studied, and our conclusion was that it is possible to build such a large central tracking system. Of course, a great deal of research and development is required. We also considered central tracking systems made of scintillating fibers or silicon microstrips, but our conclusion was that neither is a realistic candidate given the current state of technology. We began to work on computer simulation of a realistic central tracking system. Events from interesting physics processes at the SSC will be complex and will be further complicated by hits from out-of-time bunch crossings and multiple interactions within the same bunch crossing. Detailed computer simulations are needed to demonstrate that the pattern recognition and tracking problems can be solved

Centralized mouse repositories.

Science.gov (United States)

Donahue, Leah Rae; Hrabe de Angelis, Martin; Hagn, Michael; Franklin, Craig; Lloyd, K C Kent; Magnuson, Terry; McKerlie, Colin; Nakagata, Naomi; Obata, Yuichi; Read, Stuart; Wurst, Wolfgang; Hörlein, Andreas; Davisson, Muriel T

2012-10-01

Because the mouse is used so widely for biomedical research and the number of mouse models being generated is increasing rapidly, centralized repositories are essential if the valuable mouse strains and models that have been developed are to be securely preserved and fully exploited. Ensuring the ongoing availability of these mouse strains preserves the investment made in creating and characterizing them and creates a global resource of enormous value. The establishment of centralized mouse repositories around the world for distributing and archiving these resources has provided critical access to and preservation of these strains. This article describes the common and specialized activities provided by major mouse repositories around the world.

Building the foundations for a new central bank doctrine: Redefining central banks’ missions in the 21st century

Directory of Open Access Journals (Sweden)

Eric Pichet

2013-05-01

Full Text Available The 2007-2008 financial crisis demonstrated both the responsibilities that central bankers, alongside other actors, bear for turbulences of this kind as well as how economics can be used to provide central bankers and governments with the understanding and tools that they need to prevent the international financial system from collapsing. At the same time, central banks’ responses to the crisis have taken monetary policy into unknown territory. The paper’s first section diagnoses good and bad practice in post-crisis central banking; assesses the efficiency of pre-crisis doctrines; and identifies the dangers of actions exceeding certain limits. It specifically focuses on the European Central Bank’s much-debated intervention in certain peripheral bond markets, particularly Greece. The second section is more normative and lays the foundations for a social science perspective of how to manage modern central banks, an approach that draws on a variety of disciplines including economics, governance theory and management. This starts with a definition of the new doctrine and its underlying philosophy, followed by an identification of sound central banking practices (revolving around a few key concepts, notably inflation and financial stability. The missions and objectives of these practices are then defined (along with a choice of indicators, culminating in an exploration of which strategies and tools might be used in both normal and turbulent times. Lastly, a few concrete rules of governance are offered, built on the triptych of central banks’ independence, accountability and composition, with specific focus placed on the process for selecting governors fit to handle the new role that modern central banks are destined to assume in developed countries.

Central Bank independence in Latin America La independencia de la Banca Central en América Latina

Directory of Open Access Journals (Sweden)

Junguito Bonnet Roberto

1996-06-01

Full Text Available This article describes the origin and evolution of the central banks of Argentina, Brazil, Chile, Colombia, Mexico, and Venezuela, and analyzes their respective institutional structures. It also studies the contribution of the central bank to stabilization and the problems for maintaining this independence into the future.Este artículo describe el origen y la evolución de los Bancos Centrales de Argentina, Brasil, Chile, Colombia, México y Venezuela, y analiza sus respectivas estructruras institucionales. También estudia la contribución de la banca central a la estabilización y los problemas para que esta independencia se mantenga en el futuro.

The European Central Bank and the Eurosystem

OpenAIRE

Carol C. Bertaut

2002-01-01

The Eurosystem comprises the European Central Bank at its center as well as the national central banks of the twelve countries currently participating in monetary union. The European Central Bank was established in July 1998, six months before the beginning of Stage Three of economic and monetary union. Although decisions regarding monetary policy are made centrally by the Governing Council of the Eurosystem, the operational aspects of monetary policy-including open market operations, adminis...

Incidence of thrombosis in children with tunneled central venous access devices versus peripherally inserted central catheters (PICCs).

Science.gov (United States)

Kanin, Maralee; Young, Guy

2013-11-01

The recent proliferation of deep vein thrombosis in children has been attributed to the increased use of central venous catheters, specifically tunneled lines and peripherally inserted central catheters. A formal comparison of the incidence rate for deep vein thrombosis between tunneled lines and peripherally inserted central catheters has not been undertaken. Children inclusion. Data were extracted from the hospital discharge database which includes data on all procedures and up to 20 diagnoses per admission. Diagnoses and procedures were identified by International Classification of Disease, Ninth Revision coding. Patients were excluded if they received more than one central line. Data collected included type of central line, deep vein thrombosis event, and underlying medical illnesses classified according to chronic complex conditions. Over the seven year study period there was an overall rate of 73 deep vein thromboses per 10,000 hospital discharges. Of the 6915 eligible subjects, 181 had a deep vein thrombosis for an overall incidence rate of 2.6%. There were 152 thrombi (2.6%) in subjects with peripherally inserted central catheters and 29 thrombi (3.1%) in subjects with tunneled lines [OR=.83 (0.55, 1.29), p=0.38]. Despite the relative ease and simplicity of use of peripherally inserted central catheters leading to a substantial rise in their use, this study demonstrates that such lines pose a substantial risk for venous thrombosis and no difference in incidence was detected between such lines and tunneled lines. © 2013.

Dynamics-based centrality for directed networks.

Science.gov (United States)

Masuda, Naoki; Kori, Hiroshi

2010-11-01

Determining the relative importance of nodes in directed networks is important in, for example, ranking websites, publications, and sports teams, and for understanding signal flows in systems biology. A prevailing centrality measure in this respect is the PageRank. In this work, we focus on another class of centrality derived from the Laplacian of the network. We extend the Laplacian-based centrality, which has mainly been applied to strongly connected networks, to the case of general directed networks such that we can quantitatively compare arbitrary nodes. Toward this end, we adopt the idea used in the PageRank to introduce global connectivity between all the pairs of nodes with a certain strength. Numerical simulations are carried out on some networks. We also offer interpretations of the Laplacian-based centrality for general directed networks in terms of various dynamical and structural properties of networks. Importantly, the Laplacian-based centrality defined as the stationary density of the continuous-time random walk with random jumps is shown to be equivalent to the absorption probability of the random walk with sinks at each node but without random jumps. Similarly, the proposed centrality represents the importance of nodes in dynamics on the original network supplied with sinks but not with random jumps.

Community centrality and social science research.

Science.gov (United States)

Allman, Dan

2015-12-01

Community centrality is a growing requirement of social science. The field's research practices are increasingly expected to conform to prescribed relationships with the people studied. Expectations about community centrality influence scholarly activities. These expectations can pressure social scientists to adhere to models of community involvement that are immediate and that include community-based co-investigators, advisory boards, and liaisons. In this context, disregarding community centrality can be interpreted as failure. This paper considers evolving norms about the centrality of community in social science. It problematises community inclusion and discusses concerns about the impact of community centrality on incremental theory development, academic integrity, freedom of speech, and the value of liberal versus communitarian knowledge. Through the application of a constructivist approach, this paper argues that social science in which community is omitted or on the periphery is not failed science, because not all social science requires a community base to make a genuine and valuable contribution. The utility of community centrality is not necessarily universal across all social science pursuits. The practices of knowing within social science disciplines may be difficult to transfer to a community. These practices of knowing require degrees of specialisation and interest that not all communities may want or have.

Central banks: Paradise lost

OpenAIRE

Issing, Otmar

2012-01-01

The focus of the paper is to analyze how the concept behind central bank policy developed over time and how the recent financial crisis and its consequences will have an influence. While the principles of the institutional arrangement for central banks (independence, clear mandate, prohibition of monetary financing) are relevant as ever, pre- crisis consensus strategies of monetary policy have been revealed as flawed. The close monitoring of money and credit developments, a key lesson to be d...

Central European gas market perspectives

International Nuclear Information System (INIS)

Vanous, Jan

1999-01-01

This presentation deals with (1) Definition of the Central European market, (2) Factors driving up consumption of natural gas in Central and Eastern Europe, (3) Role of natural gas in regional energy consumption, (4) Position of natural gas in individual country markets, (5) Future sources of imported natural gas into the region. The Central European market are the eleven countries Albania, Bulgaria, Croatia, Czech Republic, Hungary, Macedonia, Poland, Romania, Serbia and Montenegro, Slovakia, and Slovenia, with a total population of 121 million. This market is comparable to combined France and Italy in terms of population, but only 30% of its size in terms of GDP

Close-binary central stars of planetary nebulae

International Nuclear Information System (INIS)

Bond, H.E.; Grauer, A.D.

1987-01-01

Recent observations of PN central stars identified as binary systems are reviewed. The theoretical significance of binary central stars is discussed, and the characteristics of UU Sge, V 477 Lyr, MT Ser, LSS 2018, VW Pyx, and the central star of HFG 1 are briefly summarized. All of these binaries are shown to have periods less than 1 day, and it is estimated that about 10 percent of all binary central stars are close binaries. 27 references

Central Station Design Options

DEFF Research Database (Denmark)

2011-01-01

. The work identifies the architecture, sizing and siting of prospective Central Stations in Denmark, which can be located at shopping centers, large car parking lots or gas stations. Central Stations are planned to be integrated in the Danish distribution grid. The Danish island of Bornholm, where a high...... overloading, more reference points might be necessary to represent various transformer loading levels. The subject of safety in Central Station is also addressed. A number of safety rules based on European standards apply to AC charging equipment up to 44 kW. The connection interlock and the automatic de......-energization are identified as fundamental requirements for safety in such a charging station. The connection interlock is a solution which ensures that no power is applied to the DC cable when the EV connector is not connected. The automatic de-energization device ensures that whenever a strain on the cable is detected, e...

48 CFR 52.204-7 - Central Contractor Registration.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Central Contractor....204-7 Central Contractor Registration. As prescribed in 4.1105, use the following clause: Central Contractor Registration (APR 2008) (a) Definitions. As used in this clause— Central Contractor Registration...

Comparison of blood loss between using non central part cutting knee prosthesis and distal central part cutting.

Science.gov (United States)

Malairungsakul, Anan

2014-12-01

Patients who undergo knee replacement surgery may need to receive a blood transfusion due to blood loss during the operation. Therefore it was important to improve the design of knee implant operative procedures in an attempt to reduce the rate of blood loss. The present study aimed to compare the blood loss between two types of knee replacement surgery. This is a retrospective study in which 78 patients received cemented knee replacements in Phayao Hospital between October 2010 and March 2012. There were two types of surgical procedure: 1) using an implant position covering the end of the femoral bone without cutting into the central part of the distal femoral, 2) using an implant position covering the end of the femoral bone cutting the central part of the distal femoral. Blood loss, blood transfusion, hemoglobin and hematocrit were recorded preoperatively, immediately postsurgery and 48 hours after surgery. Findings revealed that the knee replacement surgery using the implant position covering the end of the femoral bone without cutting the central part of the distal femoral significantly lowered the rate of blood loss when compared to using the implant position covering the end of the femoral bone with central cutting of the distal femor. The average blood loss during the operation without cutting at the central part of distal femoral was 49.50 ± 11.11 mL; whereas the operation cutting the central part of the distal femoral was 58.50 ± 11.69 mL. As regards blood loss, the knee replacement surgery using the implant position covering the end ofthefemoral bone without cutting the central part of distal femor was better than using the implant position covering the end of the femoral bone cutting at the central part of the distal femor.

A new paradigm of modern central banking

Directory of Open Access Journals (Sweden)

Aleksandra Szunke

2013-05-01

Full Text Available The changes in the modern monetary policy, which took place at the beginning of the twenty-first century, in response to the global financial crisis led to the transformation of the place and the role of central banks. The strategic aim of the central monetary institutions has become preventing financial instability. So far, central banks have defined financial stability as a public good, which took care independently of other monetary purposes (Pyka, 2010. Unconventional monetary policy resulted in changes the global central banking. The aim of the study is to identify a new paradigm of the role and place of the central bank in the financial system and its new responsibilities, aimed at countering financial instability.

Central hypothyroidism - a neglected thyroid disorder.

Science.gov (United States)

Beck-Peccoz, Paolo; Rodari, Giulia; Giavoli, Claudia; Lania, Andrea

2017-10-01

Central hypothyroidism is a rare and heterogeneous disorder that is characterized by a defect in thyroid hormone secretion in an otherwise normal thyroid gland due to insufficient stimulation by TSH. The disease results from the abnormal function of the pituitary gland, the hypothalamus, or both. Moreover, central hypothyroidism can be isolated or combined with other pituitary hormone deficiencies, which are mostly acquired and are rarely congenital. The clinical manifestations of central hypothyroidism are usually milder than those observed in primary hypothyroidism. Obtaining a positive diagnosis for central hypothyroidism can be difficult from both a clinical and a biochemical perspective. The diagnosis of central hypothyroidism is based on low circulating levels of free T 4 in the presence of low to normal TSH concentrations. The correct diagnosis of both acquired (also termed sporadic) and congenital (also termed genetic) central hypothyroidism can be hindered by methodological interference in free T 4 or TSH measurements; routine utilization of total T 4 or T 3 measurements; concurrent systemic illness that is characterized by low levels of free T 4 and normal TSH concentrations; the use of the sole TSH-reflex strategy, which is the measurement of the sole level of TSH, without free T 4 , if levels of TSH are in the normal range; and the diagnosis of congenital hypothyroidism based on TSH analysis without the concomitant measurement of serum levels of T 4 . In this Review, we discuss current knowledge of the causes of central hypothyroidism, emphasizing possible pitfalls in the diagnosis and treatment of this disorder.

"Christofest" New Yorgi Central Parkis / Rael Artel

Index Scriptorium Estoniae

Artel, Rael, 1980-

2004-01-01

12. II 2005. a. avatakse Christo ja Jeanne-Claude'i keskkonnainstallatsioon "The Gates" New Yorgi Central Parkis. Paralleelselt toimub Metropolitan Muuseumis näitus "Christo and Jeanne-Claude : The Gates, Central Park, New York", kus eksponeeritakse Central Parki installatsiooni ettevalmistavaid materjale: joonistusi, diagramme, fotosid jne

Centrality metrics and localization in core-periphery networks

International Nuclear Information System (INIS)

Barucca, Paolo; Lillo, Fabrizio; Tantari, Daniele

2016-01-01

Two concepts of centrality have been defined in complex networks. The first considers the centrality of a node and many different metrics for it have been defined (e.g. eigenvector centrality, PageRank, non-backtracking centrality, etc). The second is related to large scale organization of the network, the core-periphery structure, composed by a dense core plus an outlying and loosely-connected periphery. In this paper we investigate the relation between these two concepts. We consider networks generated via the stochastic block model, or its degree corrected version, with a core-periphery structure and we investigate the centrality properties of the core nodes and the ability of several centrality metrics to identify them. We find that the three measures with the best performance are marginals obtained with belief propagation, PageRank, and degree centrality, while non-backtracking and eigenvector centrality (or MINRES [10], showed to be equivalent to the latter in the large network limit) perform worse in the investigated networks. (paper: interdisciplinary statistical mechanics )

Central Laboratories Services

Data.gov (United States)

Federal Laboratory Consortium — The TVA Central Laboratories Services is a comprehensive technical support center, offering you a complete range of scientific, engineering, and technical services....

RELATION BETWEEN ISLAMIC BANK AND CENTRAL BANK

OpenAIRE

PAKSOY, H. Mustafa; ABAROSS, Nour

2015-01-01

This study deals with the nature of Islamic banks and their features, and requirements of these features in terms of control tools and methods appropriate with the particularity of their business and their relation with the traditional central bank. At the same time aims to view the relationship between Islamic bank and central bank. To explain this relation the researcher started to explain what is the central bank, objectives of central bank, and characteristics, what is Islamic bank and ob...

Distributed trace using central performance counter memory

Science.gov (United States)

Satterfield, David L.; Sexton, James C.

2013-01-22

A plurality of processing cores, are central storage unit having at least memory connected in a daisy chain manner, forming a daisy chain ring layout on an integrated chip. At least one of the plurality of processing cores places trace data on the daisy chain connection for transmitting the trace data to the central storage unit, and the central storage unit detects the trace data and stores the trace data in the memory co-located in with the central storage unit.

Accountability of Central Banks : Aspects and Quantification

NARCIS (Netherlands)

de Haan, J.; Amtenbrink, F.; Eijffinger, S.C.W.

1998-01-01

This paper starts with a discussion of the various aspects of accountability of central banks. On the basis of this discussion we construct an indicator for accountability for 16 central banks, including the European Central Bank. It is shown that the degree of accountability differs considerably

48 CFR 18.102 - Central contractor registration.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Central contractor... Central contractor registration. Contractors are not required to be registered in the Central Contractor.... (See 4.1102). However, contractors are required to register with CCR in order to gain access to the...

Lythrum salicaria (Lythraceae), nueva cita para la flora de Argentina

OpenAIRE

Torres, Cristian Daniel; Puntieri, Javier Guido

2016-01-01

Lythrum es un género cosmopolita que incluye unas 36 especies de hierbas anuales y perennes. Lythrum salicaria, una de las especies de más amplia distribución geográfica del género, crece en ambientes riparios en varios países y resulta altamente invasiva fuera de su área de distribución natural. En este trabajo se informa por primera vez la presencia de una población espontánea de L. salicaria en Argentina. Se recolectaron especímenes en la localidad de Las Golondrinas, provincia de Chubut, ...

Closed central slip injuries--a missed diagnosis?

LENUS (Irish Health Repository)

Nugent, N

2011-09-01

The extensor apparatus of the finger is a complex structure and injury can lead to significant digital dysfunction. Closed central slip injuries may be missed or diagnosis delayed because of lack of an open wound and often no radiographic abnormality, and can result in boutonniere deformities if untreated. This study aimed to quantify the number of patients attending with closed central slip injuries and to ascertain if the initial diagnosis was correct. The number of patients presenting to us over a 6 month period was recorded. The original diagnosis, time to diagnosis of central slip injury and the presence\\/absence of a boutonniere deformity were recorded. Ten patients were included in the study. Seven (70%) injuries were due to sport. Eight (80%) had a delayed diagnosis of central slip injury. Six (60%) had previously presented to general practitioners or emergency departments. Seven (70%) had boutonniere deformities. Closed central slip injuries can be missed. Simple clinical tests can diagnose central slip disruption.

Central Pain Syndrome

Science.gov (United States)

... such as neurontin (gabapentin) can be useful. Lowering stress levels appears to reduce pain. View Full Treatment Information Definition Central pain syndrome is a neurological condition caused ...

Centralized digital control of accelerators

International Nuclear Information System (INIS)

Melen, R.E.

1983-09-01

In contrasting the title of this paper with a second paper to be presented at this conference entitled Distributed Digital Control of Accelerators, a potential reader might be led to believe that this paper will focus on systems whose computing intelligence is centered in one or more computers in a centralized location. Instead, this paper will describe the architectural evolution of SLAC's computer based accelerator control systems with respect to the distribution of their intelligence. However, the use of the word centralized in the title is appropriate because these systems are based on the use of centralized large and computationally powerful processors that are typically supported by networks of smaller distributed processors

Fast network centrality analysis using GPUs

Directory of Open Access Journals (Sweden)

Shi Zhiao

2011-05-01

Full Text Available Abstract Background With the exploding volume of data generated by continuously evolving high-throughput technologies, biological network analysis problems are growing larger in scale and craving for more computational power. General Purpose computation on Graphics Processing Units (GPGPU provides a cost-effective technology for the study of large-scale biological networks. Designing algorithms that maximize data parallelism is the key in leveraging the power of GPUs. Results We proposed an efficient data parallel formulation of the All-Pairs Shortest Path problem, which is the key component for shortest path-based centrality computation. A betweenness centrality algorithm built upon this formulation was developed and benchmarked against the most recent GPU-based algorithm. Speedup between 11 to 19% was observed in various simulated scale-free networks. We further designed three algorithms based on this core component to compute closeness centrality, eccentricity centrality and stress centrality. To make all these algorithms available to the research community, we developed a software package gpu-fan (GPU-based Fast Analysis of Networks for CUDA enabled GPUs. Speedup of 10-50× compared with CPU implementations was observed for simulated scale-free networks and real world biological networks. Conclusions gpu-fan provides a significant performance improvement for centrality computation in large-scale networks. Source code is available under the GNU Public License (GPL at http://bioinfo.vanderbilt.edu/gpu-fan/.