104 research outputs found

    Determination of hydraulic parameters in experimental soil columns from the southeast of Buenos Aires province

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    La cuenca del Río Quequén Grande constituye una región representativa de los sistemas agrícolas pampeanos. El acuífero en esta región es la principal fuente de abastecimiento de agua para todos los usos, lo que pone de manifiesto la importancia de desarrollar los elementos necesarios para el estudio de la movilidad de los contaminantes a través de los suelos hacia la zona saturada. El objetivo del presente trabajo fue obtener parámetros hidráulicos bajo condiciones de saturación en columnas intactas de distintos tipos de suelos de la región, contemplando suelos de uso agrícola y natural. Se estudiaron dos series de suelo: Serie Azul y Serie Semillero Buck, con muestras tomadas en dos sectores próximos a las localidades de Lobería y La Dulce, respectivamente. Las columnas fueron eluidas con una solución acuosa de iones cloruro y se midió el incremento progresivo de conductividad. A partir de las curvas de arribo obtenidas, se ajustó la ecuación de transporte, obteniendo los valores de dispersividad y porosidad. Dichos parámetros no presentaron diferencias significativas según el uso para los suelos de Lobería, de textura franco arcillosa, indicando que la labranza no produciría modificaciones evidentes en el perfil del suelo. En La Dulce, donde los suelos poseen una textura más arenosa, los parámetros variaron según el uso del suelo, presentando una mayor dispersividad y menor porosidad del suelo bajo explotación agrícola extensiva.The Quequén Grande river basin is representative of the farming systems from the Pampas region. The aquifer is the main source of water supply for all uses, which highlights the importance to study the mobility of contaminants through the soil to the saturated zone. The aim of this study was to obtain hydraulic parameters of different soil types in the region according to land use (agricultural and natural) under saturated conditions. Two study areas were selected close to the cities La Dulce (Azul Series Soil) and Lobería (Semillero Buck Series Soil), as representatives of the dominant soil types in this area. The columns were eluted with an aqueous solution containing chloride ions and the progressive increase was measured at the end of the column. From the experimental data the breakthrough curve was adjusted using MATLAB software while dispersivity and porosity values were determined from modeled data. These parameters did not differ significantly in Lobería, so it is assumed that tillage does not produce significant changes in the soil profile. Conversely, in La Dulce land use affects the hydraulic properties of the soil leading to lower porosity and higher dispersivity values in soils under tillage use.Fil: Grondona, Sebastián I.. Universidad Nacional de Mar del PlataFil: Martínez, Daniel E.. Universidad Nacional de Mar del PlataFil: Benavente, Miguel. Universidad Nacional de Mar del PlataFil: Gonzalez, Mariana. Universidad Nacional de Mar del PlataFil: Massone, Héctor E.. Universidad Nacional de Mar del PlataFil: Miglioranza, Karina S. B.. Universidad Nacional de Mar del Plat

    The central nervous system of sea cucumbers (Echinodermata: Holothuroidea) shows positive immunostaining for a chordate glial secretion

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    <p>Abstract</p> <p>Background</p> <p>Echinoderms and chordates belong to the same monophyletic taxon, the Deuterostomia. In spite of significant differences in body plan organization, the two phyla may share more common traits than was thought previously. Of particular interest are the common features in the organization of the central nervous system. The present study employs two polyclonal antisera raised against bovine Reissner's substance (RS), a secretory product produced by glial cells of the subcomissural organ, to study RS-like immunoreactivity in the central nervous system of sea cucumbers.</p> <p>Results</p> <p>In the ectoneural division of the nervous system, both antisera recognize the content of secretory vacuoles in the apical cytoplasm of the radial glia-like cells of the neuroepithelium and in the flattened glial cells of the non-neural epineural roof epithelium. The secreted immunopositive material seems to form a thin layer covering the cell apices. There is no accumulation of the immunoreactive material on the apical surface of the hyponeural neuroepithelium or the hyponeural roof epithelium. Besides labelling the supporting cells and flattened glial cells of the epineural roof epithelium, both anti-RS antisera reveal a previously unknown putative glial cell type within the neural parenchyma of the holothurian nervous system.</p> <p>Conclusion</p> <p>Our results show that: a) the glial cells of the holothurian tubular nervous system produce a material similar to Reissner's substance known to be synthesized by secretory glial cells in all chordates studied so far; b) the nervous system of sea cucumbers shows a previously unrealized complexity of glial organization. Our findings also provide significant clues for interpretation of the evolution of the nervous system in the Deuterostomia. It is suggested that echinoderms and chordates might have inherited the RS-producing radial glial cell type from the central nervous system of their common ancestor, i.e., the last common ancestor of all the Deuterostomia.</p

    Datación de agua subterránea en el Acuífero Pampeano del sudeste bonaerense y su significado ambiental

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    El acuífero Pampeano abarca una gran extensión y es un recurso de agua de extrema importancia. La determinación del tiempo de residencia o edad aparente del agua es una herramienta moderna de gran utilidad. Si bien se asume que el mismo es portador de aguas jóvenes, el estudio de los tiempos de residencia es poco conocido. Diferentes técnicas de datación de aguas jóvenes se aplican en la provincia de Buenos Aires. Las edades aparentes determinadas con CFCs y la relación 3H/3He dan tiempos de tránsito de entre 8 y más de 50 años, evidenciando la mezcla de aguas modernas y antiguas. Aplicado a la gestión del recurso, estas edades definirían algunos sectores de vulnerabilidad alta y otros en donde la calidad no es afectada antrópicamente de manera directa, pero sí por el tiempo de contacto agua-matriz del acuífero. Las tasas de renovación hacia niveles profundos contribuyen a definir una mayor peligrosidad de sobreexplotación.The Pampeano Aquifer covers extented areas representing a water resource of great importance. The estimation of residence time or water aparent age is a modern and usefull tool. Even though it is assumed to contain young waters, residence times are not well known. Different tracer techniques used for young waters are applied in Buenos Aires Province. Aooarent ages obtained from CFCs and 3H/3He result in transit times between 8 and 50 years, showing the mixing of young and olg groundwater. In the context of water resources management, these ages would define high aquifer vulnerability in some areas, while in other sectors water quality is not directly affected by antropogenic activities but it could be affected by large water-rock interaction times. Water renewal rates through deeper levels imply over-exploitation risks.Universidad Nacional de La Plat

    Deleción 14q proximal, presentación de dos casos y revisión de la literatura

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    Dismorfología, Citogenética y Clínica: Resultados de estudios sobre los datos del ECEMCHere we present two unrelated cases that came to our service for families that are looking for information on the diagnostic on malformation syndromes and infants with congenital defects. Both cases show as common signs psychomotor delay, microcephaly, corpus callosum agenesis and inespecific facial phenotype. We perform a high resolution G-bands karyotypes, and both of them showed a "de novo" deletion in the proximal region of a chromosome 14, with different break points but with a common region deleted. The karyotype of the first case was 46,XY, del(14)(q12;q21.1), and the karyotype of the second case 46,XX del(14)(q11.2;q13.1). We discussed the possible candidates genes that could be related with the phenotype and review the different reported cases.N

    Cat-Owner Relationship and Cat Behaviour : Effects of the COVID-19 Confinement and Implications for Feline Management

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    The aim of this study was to explore the effects of the Italian COVID-19 lockdown on the cat-owner relationship and on cat behaviour. In order to do so, we used a questionnaire to obtain information on the owner and cat's demographics, living environment, cat behaviour, and possible changes in some aspects of the cat-owner relationship. The questionnaire was distributed online when the lockdown was still ongoing and was completed by 548 cat owners, mainly women. Our findings suggest that the greater amount of time that owners spent at home with their cats, as a consequence of the social restrictions, had a positive effect on the owner's perception of their relationship with their cat (e.g., higher frequency of interaction, greater emotional closeness, reduced perceived costs of caring for the cat). Similarly, the lockdown seemed to have improved the welfare of many cats, as suggested by the positive changes in many of their behaviours, even for those cats with pre-existing behavioural problems. Overall, our findings suggest that the lockdown provided many cats with a more thriving physical and social environment. They also highlight the need to reconsider some cat management practices commonly implemented in non-exceptional circumstances. The restrictive measures implemented to stem the spread of COVID-19 abruptly changed the lives of many cats and their owners. This study explored whether the lockdown in Italy affected the cat-owner relationship, as well as cat behaviour and welfare. A survey that included questions on owner and cat's demographics, living environment, cat behaviour and a modified version of the Cat/Dog Relationship Scale (C/DORS) was distributed online during the lockdown and was completed by 548 cat owners, mainly women (81.6%). With regard to the C/DORS subscales, both emotional closeness and cat-owner interactions increased during confinement, as opposed to a reduction in perceived costs. The effect of the type of job, family role and owner's age on the C/DORS scores suggests that the relationship improved for those owners that, due to the lockdown, increased the time spent with their cats. For 58.8% of respondents, their cat's general behaviour did not change, but when changes occurred, they were mostly positive (20.4%). Attention-seeking and demanding behaviours were the most increased during lockdown (25.7%). Cats with pre-existing problematic behaviours tended to either remain stable or improve during confinement. The overall positive effects of lockdown-related environmental changes on a cat's behaviour suggest that some aspects of commonly implemented cat management practices should be revised to improve cat welfare in normal circumstances

    Determinación de parámetros hidráulicos en columnas experimentales de suelos del sudeste de la provincia de Buenos Aires

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    The Quequén Grande river basin is representative of the farming systems from the Pampas region. The aquifer is the main source of water supply for all uses, which highlights the importance to study the mobility of contaminants through the soil to the saturated zone. The aim of this study was to obtain hydraulic parameters of different soil types in the region according to land use (agricultural and natural) under saturated conditions. Two study areas were selected close to the cities La Dulce (Azul Series Soil) and Lobería (Semillero Buck Series Soil), as representatives of the dominant soil types in this area. The columns were eluted with an aqueous solution containing chloride ions and the progressive increase was measured at the end of the column. From the experimental data the breakthrough curve was adjusted using MATLAB software while dispersivity and porosity values were determined from modeled data. These parameters did not differ significantly in Lobería, so it is assumed that tillage does not produce significant changes in the soil profile. Conversely, in La Dulce land use affects the hydraulic properties of the soil leading to lower porosity and higher dispersivity values in soils under tillage use.La cuenca del Río Quequén Grande constituye una región representativa de los sistemas agrícolas pampeanos. El acuífero en esta región es la principal fuente de abastecimiento de agua para todos los usos, lo que pone de manifiesto la importancia de desarrollar los elementos necesarios para el estudio de la movilidad de los contaminantes a través de los suelos hacia la zona saturada. El objetivo del presente trabajo fue obtener parámetros hidráulicos bajo condiciones de saturación en columnas intactas de distintos tipos de suelos de la región, contemplando suelos de uso agrícola y natural. Se estudiaron dos series de suelo: Serie Azul y Serie Semillero Buck, con muestras tomadas en dos sectores próximos a las localidades de Lobería y La Dulce, respectivamente. Las columnas fueron eluidas con una solución acuosa de iones cloruro y se midió el incremento progresivo de conductividad. A partir de las curvas de arribo obtenidas, se ajustó la ecuación de transporte, obteniendo los valores de dispersividad y porosidad. Dichos parámetros no presentaron diferencias significativas según el uso para los suelos de Lobería, de textura franco arcillosa, indicando que la labranza no produciría modificaciones evidentes en el perfil del suelo. En La Dulce, donde los suelos poseen una textura más arenosa, los parámetros variaron según el uso del suelo, presentando una mayor dispersividad y menor porosidad del suelo bajo explotación agrícola extensiva

    Monososomy 1p36: A clinically recognizable syndrome

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    Dismorfología, Citogenética y Clínica: Resultados sobre los datos del ECEMCPure 1p36 deletion is considered a new delineated syndrome that probably is a contiguous gene syndrome, presenting a pattern of clinical manifestation that may be recognizable. This includes moderate to severe psychomotor retardation, hypotonia, microcephaly, postnatal growth retardation, seizures and craniofacial dysmorphism (deep set eyes, low nasal bridge, large anterior fontanelle, midface hypoplasia) which should lead to perform a chromosomal study particularly focussed on this type of deletion. Terminal region 1p is difficult to visualize and its alterations will only be detected in a High Resolution G-band karyotype, followed by Fluorescence in situ Hybridization techniques (FISH). Here we present a case which was diagnosed as having a 1p36.22 deletion with High Resolution G-band karyotype confirmed by telomeric FISH.N

    Síndromes muy poco frecuentes

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    Dismorfología, Citogenética y Clínica: Resultados de estudios sobre los datos del ECEMCIn an attempt to facilitate the knowledge of the malformation syndromes that have very few frequencies to pediatricians and first health care physicians, particularly to those of rural areas, we have selected six new syndromes. As in previous years, the syndromes are selected from the ECEMC database registry. In this Boletín we include the following syndromes: Townes-Bröcks, MMT, Smith-Lemli-Opitz, Coffin-Siris, Espleno-gonadal fusion, and Silver-Russell syndromes. For each syndrome, we described the most important clinical characteristics, and the present knowledge of their causal factors.N

    Very few frequent syndromes

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    Dismorfología, Citogenética y Clínica: Resultados sobre los datos del ECEMCThis section is based on two facts: First, that the majority of the malformation syndromes are very few frequent. Second, the progressive generalization in our country of the prenatal diagnosis with a high resolution echography performed to all women between 18-20 weeks of gestation as a Service of the National Health System, together with the possibility of voluntary interruption of gestation if fetal anomalies are detected. Thus, the impact of prenatal diagnosis is that the frequency at birth of these syndromes shows an important and progressive decreasing trend. For these reasons, in addition to the difficulty for pediatricians and geneticists or our population to diagnose these usually rare syndromes, the impact of prenatal diagnosis increases the usual difficulties that the young pediatricians and geneticists have to identify these pathologies. This increases the possibility that some affected patients can remain undiagnosed for a long time, or even never be diagnosed. As started last year in this section of the "Boletín del ECEMC", we present other six syndromes of low frequency in our country.N

    Diagnostic, etiologic, and genetic aspects of congenital ichthyoses at birth: Characteristics of the ECEMC cases

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    Dismorfología, Citogenética y Clínica: Resultados de estudios sobre los datos del ECEMCThe Ichthyoses constitutes a large family of genetic skin diseases characterized by dry skin and variable degrees of blisters and scales. There are at least twenty varieties of ichthyosis, with a wide range of severity and associated symptoms, and genetic heterogeneity (autosomal dominant, autosomal recessive, and X-linked inheritance). The clinical symptoms, which are non-specific, may not be apparent. We have attempted to provide a classification of the ichthyoses and some guidance for the diagnosis and management of these conditions. The present classification is based in the type of alteration of the skin layer, the molecular findings, the biochemical characteristics, and the family history.There are three main categories, which include different subgroups of ichthyoses: 1) Those that are caused by an altered process of keratinocytic diferenciation (altered intermediate filaments/keratins). This category includes the following subgroups: a) Harlequin fetus; b) bullous erythroderma ichthyosiformis congenital; c) Ichthyosis bullosa of Siemens; d) Ichthyosis hystrix of Curth-Macklin; and e) Ichthyosis vulgaris. 2) Those that are caused by a deficient formation of the cornified envelope (transglutaminase 1 enzyme deficiency). In this category we include two main subgrups: a) Lamellar ichthyosis AR, which includes i) ichthyosis lamellar (IL1, IL2, IL3, IL4, and IL5), and ii) ichthyosiform erythroderma congenital nonbullous, and b) Nonlamellar ichthyosis and nonerythrodermic congenital ichthyosis AR. 3) Those caused by an abnormal steroid sulfatase (X-linked Ichtyosis). In spite of having only data at birth and the lack of molecular analysis, we attempted to classify the ECEMC cases according to this classification using available clinical data. We also calculated the frequency of this disease identified at birth, and provide some guidance for the clinical diagnosis, the management of the affected newborn, and the information that should be offered to the parents.N
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