Top PDF Taphonomic analysis of the late Pleistocene small mammals of Quequén Salado river, Buenos Aires, Argentina

Taphonomic analysis of the late Pleistocene small mammals of Quequén Salado river,
Buenos Aires, Argentina

Taphonomic analysis of the late Pleistocene small mammals of Quequén Salado river, Buenos Aires, Argentina

RESUMO − A análise tafonômica foi realizada em pequenos restos de mamíferos recuperados de acumulações fossilíferas, interpretadas como pelotas de regurgitação inteiras e fragmentadas, das falésias pleistocênicas do Rio Quequén Salado (Buenos Aires, Argentina). Além disso, a provável fonte da acumulação e algumas características associadas aos processos de pós-soterramento da preservação são discutidas. A partir das informações disponíveis, é possível, através da análise da representação anatômica dos restos e do grau de digestão, mostrar afinidades com acumulações comuns formadas por aves noturnas de rapina. No entanto, os padrões de quebra são tendenciosos para esta associação, pois mostra valores muito mais elevados do que em recente análise feita sobre estas aves. Fraturas ósseas de origem diagenética encontradas em elementos esqueletais provavelmente ocultam as fraturas produzidas no momento da predação. Microestruturas características dos restos conservados em pelotas são indicativos de boa preservação, indicando um soterramento rápido. Elementos associados, interpretados como provenientes de pelotas desagregadas também podem ter sido soterrados rapidamente, não apresentando intemperismo. Do ponto de vista bioestratigráfico e com base nos megamamíferos associados, essa assembleia fossilífera pode ser atribuída ao Piso/Idade Lujanense, Pleistoceno tardio.
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Reconquista river basin in the metropolitan planning of Buenos Aires (Argentina): Scope, problems and proposals

Reconquista river basin in the metropolitan planning of Buenos Aires (Argentina): Scope, problems and proposals

Aunque a un ritmo menor que en las décadas anteriores, durante los 70 Buenos Aires se siguió expandiendo, completando intersticios entre los principales ejes de movilidad metropolitana (Figura 6), al mismo tiempo que dejaba vacíos sin urbanizar correspondientes a extensas zonas de humedales y a grandes complejos militares, como Campo de Mayo, la Base Aérea de El Palomar o el Cuartel V 11 . Si bajo el modelo de desarrollo industrial se había completado un primer anillo metropolitano de carácter fabril, a partir de mediados de la década de 1960 el primero se terminó de consolidar y fue el segundo el que tuvo los mayores índices de crecimiento. La contaminación de ríos, canales y arroyos, del suelo y de las aguas subterráneas, que provenía de la actividad industrial y de una urbanización que se extendía sin infraestructuras de servicios básicos, a expensas de la calidad de los recursos naturales, fue considerada un problema central de la región de Buenos Aires en el Estudio del SIMEB, realizado entre 1975 y 1979 (Argentina, 1979) 12 .
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Analysis of the lithic assemblage from the initial occupation (ca. 10000 years BP) of the Cueva El Abra site (Buenos Aires, Argentina

Analysis of the lithic assemblage from the initial occupation (ca. 10000 years BP) of the Cueva El Abra site (Buenos Aires, Argentina

This paper presents the results of the lithic techno-morphological analysis of Cueva El Abra Site (Buenos Aires, Argentina) corresponding to the Late Pleistocene/Early Holocene transition (10270 ± 200 and 9834 ± 70 years BP). Based on the archaeological evidence Cueva El Abra was defined as a base camp of multiple activities. This cave presents the most abundant lithic assemblage recovered in stratigraphic sequence for this chronological period in the Humid Pampas sub-region. The results of the analysis evidence a wide diversity of rocks used for the manufacture of artifacts, mainly the local Orthoarcites of Balcarce Formation (medium-fine, medium and coarse grain) and the non-local Orthoarcites of Sierras Bayas Group (fine grain and better quality for flintknapping). On this rock, almost all the stages of the operative chain are evidenced.
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Energetic analysis of four crop sequences in Buenos Aires Province, Argentina

Energetic analysis of four crop sequences in Buenos Aires Province, Argentina

The use of fossil energy in agriculture is an important issue. In fact, fossil energy is a scarce and non-renewable resource, which needs to be preserved for future generations but whose consump- tion has been linked to global warming. The aim of this work was to analyze the energy flows and evaluate the energy balance (BE) and energy efficiency (EE) of four crop sequences (rotations): oat (Avena sativa L.)/soybean (Glycine max (L.) Merr.), barley (Hordeum distichun L.)/soybean , rapeseed (Brassica napus L.)/soybean, wheat (Triticum aestivum L.)/soybean, produced under two different levels of technological management in Buenos Aires (Argentina). Incoming energy to crop sequenc-
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Ichthyofauna of two streams in the high basin of the Samborombón River, Buenos Aires province, Argentina.

Ichthyofauna of two streams in the high basin of the Samborombón River, Buenos Aires province, Argentina.

(UBA), Área de Medicina, Producción y Tecnología de Fauna Acuática y Terrestre. glópezfcvuba@yahoo.com.ar Abstract: The ichthyofauna of the Manantiales (35°02’34”S; 58°19’37”W) and El Portugués (35°04’16”S; 58°26’09”W) streams, both of them pertaining to the high basin of the Samborombón River, in the Province of Buenos Aires, Argentina, was studied. Abundance, specific richness, diversity and temporary distribution were considered throughout an annual cycle. The specific diversity between both streams was compared and the physi- cal and chemical parameters of the environment analizad. In total 8595 specimens were captured, pertaining to 20 species, 11 families and 5 orders. The order Characiformes was the most widely represented with 10 species and a relative abundance of 50%, followed by the order Siluriformes with 6 species and a relative abundance of 30%. The specific richness in the Manantiales was of 20 species, the annual diversity index was 1.42 and the uniformity index was 0.58. The specific richness in El Portugués was of 17 species, the annual diversity index was 1.51 and the uniformity index was 0.64. Differences in the composition of dominant species were observed. The diversity values are similar to that recorded in Pampasia and southern Brazil streams.
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Structure and organization of a perinatal network in the greater Buenos Aires (Buenos Aires province, Argentina)

Structure and organization of a perinatal network in the greater Buenos Aires (Buenos Aires province, Argentina)

Diversos trabajos han mostrado las especificidades de esta región a la hora de implementar redes de servicios de salud. En Brasil, una serie de estudios de caso han analizado experiencias específicas de redes de servicios, identificando los problemas que dificultan su gestión y sugiriendo su efectividad (Dos Santos, 2013). Otros autores de ese mismo país destacan la importancia de trabajar conjuntamente las estrategias de redes de servicios y regionalización de la atención en vistas de lograr respuestas que atiendan las características de los disímiles territorios locales y regionales (D´Avila Viana et al., 2015). Desde Argentina, Maceira & Palacios (2012) han trabajado sobre la experiencia de dos redes de atención perinatal de la Provincia de Buenos Aires e identificaron los límites para su desempeño, entre los que se destacan la descentralización provincial y municipal (la primera por suponer limitaciones normativas al planificar e implementar acciones sanitarias y la segunda en relación a las dificultades de coordinación entre hospitales provinciales y centros de salud municipales) y la informalidad con que se estructuran y funcionan tales redes.
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Periphytic diatoms of the Sauce Grande River Basin (Buenos Aires, Argentina)

Periphytic diatoms of the Sauce Grande River Basin (Buenos Aires, Argentina)

ABSTRACT – Periphytic diatoms of the Sauce Grande River Basin (Buenos Aires, Argentina). This paper is part of a study about periphytic diatoms from rivers of the Sauce Grande River Basin, above the Paso de las Piedras Reservoir. This is the first step in using these organisms as bioindicators in the basin. Samples were collected during August to September 2000 in 14 sites in the main course and tributaries. The analysis of the samples with light and scanning electron microscopes allowed us to identify 92 infrageneric taxa. Achnanthes cf. minutissima var. inconspicua, Navicula cryptotenelloides, N. microcari, and N. reichardtiana are firstly described for the country. Craticula halophila, Cyclotella pseudostelligera, Denticula valida, Diatoma vulgare, Fistulifera saprophila, Fragilaria aff. elliptica, Hippodonta capitata, Luticola mutica, Navicula capitatoradiata, N. tripunctata, Nitzschia amphibia, N. capitellata, N. cf. communis, N. fonticola, N. cf. gandersheimiensis f. tenuirostris, N. heufleriana, N. inconspicua, N. microcephala, N. paleaceae, Pinnularia borealis, Planothidium
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Distribution of three species of armadillos in the Pampaean region of the Province of Buenos Aires, Argentina

Distribution of three species of armadillos in the Pampaean region of the Province of Buenos Aires, Argentina

comunes y abundantes de la región pampeana. Dada la intensidad y dinámica de uso de la tierra a nivel global, y puntualmente en esta región, es evidente que para poder plantear pautas de conservación y/o manejo es nece- sario tener actualizada la distribución de las especies (Tognelli et al., 2011; Guisan et al., 2013). El objetivo de esta nota es actualizar la distribución de tres especies de armadillos (peludo C. villosus, piche llorón C. vellerosus y mulita D. hybridus) de la región pampeana comprendida en la provincia de Buenos Aires, Argentina, con respecto al trabajo de Abba y Vizcaíno (2011) y aclarar algunos registros du- dosos o errores que contenía dicha publicación. En el marco de un proyecto sobre agroeco- sistemas y actividad de armadillos (ver Abba et al., 2015) se obtuvieron registros de tres especies presentes en la región pampeana de Buenos Ai- res mediante trabajos de campo llevados a cabo durante dos años (2011 y 2013). Los nuevos registros fueron contrastados con la informa- ción presentada en Abba y Vizcaíno (2011). Los armadillos fueron registrados mediante obser- vaciones directas (OD) y evidencias indirectas (cuevas y hozaduras, EI). Para distinguir la especie asociada a cuevas y hozaduras se tuvo en cuenta la forma de la estructura como así también su ancho (ver Abba et al., 2005, 2007, 2015). Cada año se realizaron dos campañas de 25 días, en diciembre-enero y en mayo-junio, donde se recorrieron de manera sistemática 25 partidos (cinco en cada unidad ecológica, ver Abba et al., 2015). Se muestrearon un total de 392 lotes (de 10 a 400 ha) realizando en cada uno de ellos una transecta de 600 x 6 m (ver Abba et al., 2015). Asimismo, de manera asis- temática se recorrió toda la región pampeana de la provincia (15 000 km recorridos en total) registrando la presencia de los armadillos por observaciones directas de animales atropellados o registrados en los bordes de las rutas o ca- minos vecinales. Los registros de presencia de cada especie se presentan teniendo en cuenta el partido y la unidad ecológica (ver figuras y Material Suplementario).
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Estructuras de deformación en la margen noreste del Río Quequén Salado, Provincia de Buenos Aires, Argentina

Estructuras de deformación en la margen noreste del Río Quequén Salado, Provincia de Buenos Aires, Argentina

Abstract. Deformation structures in the northeast margin of the Quequén Salado River, Buenos Aires Province, Argentina. A profile of the Quequén Salado River, Buenos Aires province, Argentina was estudied, with the aim of establishing the trigger mechanisms of sedimentary struc- tures found in the same. The lithofacies, biofacies and deformations were analysed, which allowed proving the processes that caused them and the triggers valuation. Sedimentary levels were studied dominated by fine sandstones and siltstones with light colours, containing charophytes, diatoms, gastropods, and remains of oxidized roots. These identifications allowed the paleoenvironmen- tal reconstruction of the basal section of the profile, characterized by a continental environment, a freshwater lagoon stage of the upper Pleistocene (Luján Fm.). A predeformacional morphology was identified represented by an alluvial plain connected with deposits of shallow environments. The moment and the mechanism of the deformation were established, which is circumscribed to a process of basal sliding, following a plane inclined, lithologic heterogeneity and pressure conditions in the fragile-ductile limit. The trigger process would be assigned to a shock seismic discarding an own synsedimentary deposition. There are few mentions in the region of this type of deformations caused by earthquakes in the Andean region.
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The paleoenvironmental record from the Late Pleistocene to the present in Laguna Lobos, Buenos Aires, Argentina

The paleoenvironmental record from the Late Pleistocene to the present in Laguna Lobos, Buenos Aires, Argentina

las lomas de la llanura pampeana”. Años más tarde, Tapia (1932) señalaba que “Sobre el Plioceno superior, separado por un plano de denudación, claramente visible en las barrancas de la laguna, las capas loéssicas tan características del Bonaerense aparecen con sus concreciones y nódulos de tosca”. En nuestro concepto este depósito representa al Bonaerense de los esquemas clásicos de la literatura geológica argentina, redefinido como Formación Buenos Aires por Riggi et al. (1986). Asimismo, su paleosuelo cuspidal se correlaciona con la unidad pedoestratigráfica Geosuelo “Sin Nombre” (Tonni & Fidalgo, 1978), cuya pedogénesis se corresponde con la etapa húmeda subsiguiente, durante la cual se acumuló en el lecho lagunar la Formación Luján, Miembro La Chumbiada (Dillon & Rabassa, 1985). La mayoría de los autores que se han ocupado de ésta unidad, la refieren al Pleistoceno tardío (Fidalgo et al., 1975). Sin embargo, las dataciones paleomagnéticas le asignan Edad Brunhes, con una antigüedad < 0,73 Ma, circunstancia que permitiría asignarle edad pleistocena media a tardía. Por otra parte, Zárate (2005) considera que no obstante que la cronología del Ensenadense y del Bonaerense es inferida básicamente a partir del análisis magnetoestratigráfico, hasta ahora, la identificación litológica y la determinación de sus límites estratigráficos son aspectos aún debatibles, criterio que compartimos con dicho autor.
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Contribution to the knowledge of the birds of Quilmes and Avellaneda (Buenos Aires, Argentina)

Contribution to the knowledge of the birds of Quilmes and Avellaneda (Buenos Aires, Argentina)

RESUMEN. En este trabajo se presentan nuevos registros de aves para la costa rioplatense de los partidos de Quilmes y Avellaneda (Provincia de Buenos Aires, Argentina). La zona estudiada incluye dos áreas protegidas: Reserva Natural Municipal Los Sauces y el Parque Natural y Reserva Ecológica Municipal Selva Marginal Quilmeña, como también sectores sin categoría de conservación, abarcando en conjunto más de 300 hectáreas. Las observaciones se realizaron tanto por el Club de Observadores de Aves de Bernal como por estudiantes de la Facultad de Ciencias Naturales y Museo (Universidad Nacional de la Plata). Se adiciona un total de 31 especies nuevas en relación a trabajos anteriores, pertenecientes a las familias Tinamidae (1), Falconidae (1), Anatidae (2), Ardeidae (1), Rallidae (3), Strigidae (2), Cuculidae (1), Alcedinidae (1), Furnariidae (7), Sturnidae (1), Motacillidae (1), Thraupidae (2), Tityridae (1), Tyrannidae (5), Icteridae (2). Destacan los registros de Spartonoica
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Effects of litigation on health and equity: The case of the Province of Buenos Aires, Argentina

Effects of litigation on health and equity: The case of the Province of Buenos Aires, Argentina

actores como las prestaciones solicitadas son representativos de los sectores medios y altos de la población, mientras que los sectores bajos y vulnerables quedarían fuera del universo litigante. Sin embargo, recientemente también se ha señalado que estos efectos dependen del contexto concreto en que este litigio se inicia y se ha rescatado la importancia de esta herramienta para garantizar el derecho a la salud de los más vulnerables. Nuestro trabajo busca analizar esta problemática para el caso de Argentina a partir del estudio del litigio en salud en la Provincia de Buenos Aires. Los resultados de este análisis dan cuenta de una confirmación parcial de la tesis de los efectos distorsivos y de líneas jurisprudenciales que pueden habilitar una discusión más robusta sobre el acceso equitativo a la salud.
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Strategic Analysis Tools (SAT) application at small & medium enterprises in the norrth are of Buenos Aires, Argentina

Strategic Analysis Tools (SAT) application at small & medium enterprises in the norrth are of Buenos Aires, Argentina

This paper studies the nature and amplitude of Strategic Analysis Tools (SAT) application in SMEs located in emerging countries, specifically the North Area of Buenos Aires, Argentina (NABAA), where there are no formal studies on the subject. It is intended to understand their contribution to strategic options formulation and implementation. A survey to SMEs’ owners/executives /managers in NABAA and interviews with specialists were applied, intending to analyze the use of these tools to facilitate the creation of strategic options, their support in assessing a competitive position and their promotion of superior performance. The results of this investigation developed that SAT and their related KPIs (Key Performance Indicators) should be considered in SMEs in order to improve strategy formulation and find better ways to implement it.
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Micromorphology of paleosols at the continental border of the Buenos Aires province, Argentina

Micromorphology of paleosols at the continental border of the Buenos Aires province, Argentina

Due to the high content of volcanic shards, the sediment can be readily identified in the field where it appears as massive, loose, or with a weak to moderate structure grade; this allows an easier identification and a regional correlation The presence of zones with higher content of volcanic shards in the Pampean sediments has also been observed in other profiles (González-Bonorino, 1955; Riggi et al., 1986; Teruggi and Imbellone, 1987; Nabel, 1993; Blasi et al., 2001), which indicates more intense volcanic events. The presence of purely eolian loess and water reworked loess (Teruggi, 1982; Pye, 1987) in the Pampean sediments is mentioned by Frenguelli (1955) who established criteria for their differentiation based on field evidences. In the Quaternary successions of the NE continental border of the Pampean plain, many paleochannels and zones with platy stratification produced by water action are observed. In the studied profiles, there is a predominance of reworked sediments with rounded and subrounded clasts consisting of a material similar to the soil matrix; they have variable sizes up to 3 cm in diameter; they are coated with oxide patinas and are harder than the matrix. According to field evidence, the sediments resembling primary loess correspond to the bottom of the D and E units in the Airport profile and to bottom of the F unit in the San Pedro profile. In spite of this, the reworked character of loess is revealed by the presence of clasts observed at microscopic level.
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Hepatitis C virus diversification in Argentina: comparative analysis between the Large City of Buenos Aires and the small rural town of O'Brien

Hepatitis C virus diversification in Argentina: comparative analysis between the Large City of Buenos Aires and the small rural town of O'Brien

showed that HCV infection was more frequent in people older than 50 years, with the highest prevalence (22%) in the group aged between 70–79 years [16]. A similar situation has been reported from OBrien, another small rural town of approximately 2300 inhabitants located in Buenos Aires Province [14]. The overall prevalence of HCV infection in O’Brien was found to be 5.6%, 0.6% in individuals aged ,40 years and 12.6% in those .40 years, with a peak of 23% in the group aged 60–70 years. All patients from O’Brien were infected with HCV genotype 1b. However, the information about the origin of HCV infection was evaluated from the epidemiological forms and phylogenetic analysis was restricted. Therefore, it would be interesting to perform a strong phylogenetic analysis and complement it with a coalescence analysis in order to compare the diversity and origin of samples from small towns and a large cosmopolitan city.
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Magnetic signal in soils of the centre of Buenos Aires province, Argentina

Magnetic signal in soils of the centre of Buenos Aires province, Argentina

The coercivity of remanence (H cr ) and S-ratio (Coef. S) values, as well acquisition of isothermal remanent magnetization curves design (Fig. 7), are consistent with the magnetic signature of ferrimagnetic species. According to Peters and Dekkers’ graph (2001), the samples correspond to magnetite-titanomagnetites- maghemite (Fig. 8a). These data are consistent with those indicated for other soils with loessic parent materials of the Pampean region where it has been determined by different ways that the detrital magnetic composition mainly corresponds to titanomagnetites with low titanium. According to King et al. (1982) (Fig. 9) the magnetic grains would be less than 1 micron diameter, and are considered of single domain (SD). Samples of horizons A and B present smaller magnetic particles than the parent materials (C horizons). Besides, the frequency- dependent susceptibility indicates that the relative presence of ultrafine particles (SP) increase in the solum horizons, in which there is also recorded, taking into account the inter-parametric relations, an increase of fine magnetic particles (SD and SD- SP limit) (Fig. 10). Finally, the decline of H cr values at the A and B horizons would indicate that the magnetic particles of pedogenetic origin formed in these horizons have low coercivity (Fig. 8b).
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Cladodes anatomy of Opuntia (Cactaceae) from the province of Buenos Aires (Argentina). - Sociedad Argentina de Botánica

Cladodes anatomy of Opuntia (Cactaceae) from the province of Buenos Aires (Argentina). - Sociedad Argentina de Botánica

reconstituted by immersion in water and placed in an oven at 30ºC for 24-72 h, then fixed in FAA. To perform anatomy study a small piece from the middle part of the cladode was used. To study characteristics in surface view transparent material was prepared by the following technique of LAMCE Laboratory: at room temperature, samples of cladodes were submerged in a solution of sodium hydroxide (5%) add sodium hypochlorite (5%), ratio 1: 1 for 2-5 days. At completion of the bleaching process, five washed in distilled water were carried out to remove the sodium hydroxide and hypochlorite. Samples were then transferred into a solution of chloral hydrate (5%) for 24-48 h. To analyze the structure, small pieces of cladodes were sectioned transversally, bleached in sodium hypochlorite (50%), washed three times with distilled water, and stained with alcoholic solution of safranin (80%). Slides were mounted on glycerin jelly (Johansen, 1940).
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Impact of the Morón stream on water quality of the Reconquista River  (Buenos Aires, Argentina)

Impact of the Morón stream on water quality of the Reconquista River (Buenos Aires, Argentina)

Key words: heavy metals, Mor6n stream, organic contamination, Reconquista River, urban river, water quality.. The Reconquista River basin has a surface of 1.67 10"ectares 72,000 [r]

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Type localities of small mammals in Patagonia: Hatcher’s expedition to the Meseta del Lago Buenos Aires, Santa Cruz, Argentina

Type localities of small mammals in Patagonia: Hatcher’s expedition to the Meseta del Lago Buenos Aires, Santa Cruz, Argentina

Para las mismas fechas obtienen varias aves acuáticas (Tabla 2), lo cual resulta muy impro- bable en los cañadones “desprovistos de agua”. Pero existe un río mallinoso 5 km al NW del campamento de Cañadón Saco cuyo nombre, Ecker, recuerda notablemente a Eche, Eke o Else. Este río, que nace en la Meseta del lago Buenos Aires y es tributario del río Pinturas, está indicado en forma inequívoca en el mapa de Hatcher (1903). Suponemos que para Col- burn, el amplio y pastoso valle del río Ecker, allí donde luego se construiría la Ea. Casa de Piedra, sería un lugar de caza y trampeo ideal. Lo hemos recorrido y las tuqueras son densas y cubren por kilómetros sus márgenes (Fig. 3). En consecuencia, se pueden restringir las loca- lidades típicas de E. morgani y C. colburni al río Ecker en Ea. Casa de Piedra, ca. 10 km al SSW de su confluencia con el río Pinturas (47.12°S, 70.86°W, 700 m; Carta Topográfica IGN 4772- 24, 1947, “Río Pinturas”, escala 1:100 000).
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Epidermal characteristics of toxic plants for cattle from the Salado river basin (Buenos Aires, Argentina) - Sociedad Argentina de Botánica

Epidermal characteristics of toxic plants for cattle from the Salado river basin (Buenos Aires, Argentina) - Sociedad Argentina de Botánica

Solanaceae (14 spp. surveyed): They had mainly two types of stomata: anisocytic and anomocytic. We also occasionally found paracytic stomata. This feature was also mentioned by Bruno et al. (1999), Cosa et al. (2000), Barboza et al. (2001), and Stenglein (2001). Solanum glaucophyllum presented glabrous epidermis (Mansilla et al., 1999; Stenglein, 2001), while the rest of species showed different types of hairs, ie. (1) simple, conical 1-2-many celled in almost all the genera, (2) Y-shaped (in Physalis and rarely in Salpichroa and Solanum), (3) dendritic (in Physalis and rarely in Solanum), and (4) glan- dular capitate (head 2-many celled) in almost all ge- nera. Our results agree with hair types found in Datura by Carpano et al. (1990) and Licovsky et al. (2002). Our results accord to Metcalfe & Chalk (1950, 1979) and Colares et al. (1999) who found the same hair types for Nicotiana, Physalis and Salpichroa. Our results also agree with Cabrera (1979) who found the same features in Physalis, and Cabrera (1979) and Stenglein (2001) in different species of Solanum.
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