46 research outputs found

    Aplicación de un modelo de red neuronal para la clasificación de sistemas lacunares pampeanos

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    The pampean shallow lakes present different distributions in their trophic chains, the latter being cause and consequence of the state of the lacunar systems. In order to determine how each of the measured variables —climatic, edaphic, morphometric, physicochemical and biological— in contributes to the general state of the lake, an Artificial Neural Network (ANN) model is built. The ANN is capable of processing a large number of variables and returning a classification that will allow determining it’s the trophic state. The information from satellite images is one of the input variables. Hence, on a first stage, the construction of a ANN model is intended to obtain a weight for each one of the visible specter bands and near infrared bands from LANDSAT and to pick the most representative value that the image returns. This value will be used as input to the ANN that will be then trained to return a classification of the shallow lakes according to the three observed patterns in the relation between phytoplankton, zooplankton, fish and their link with to nutrient abundance and watershed management.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

    Insecticidal Activity of Four Essential Oils Extracted from Chilean Patagonian Plants as Potential Organic Pesticide

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    Patagonia is a geographical area characterized by a wide plant biodiversity. Several native plant species are traditionally used in medicine by the local population and demonstrated to be sources of biologically active compounds. Due to the massive need for green and sustainable pesticides, this study was conducted to evaluate the insecticidal activity of essential oils (EOs) from understudied plants growing in this propitious area. Ciprés (Pilgerodendron uviferum), tepa (Laureliopsis philippiana), canelo (Drimys winteri), and paramela (Adesmia boronioides) EOs were extracted through steam distillation, and their compositions were analyzed through GC–MS analysis. EO contact toxicity against Musca domestica L., Spodoptera littoralis (Boisd.), and Culex quinquefasciatus Say was then evaluated. As a general trend, EOs performed better on housefly males over females. Ciprés EO showed the highest insecticidal efficacy. The LD50(90) values were 68.6 (183.7) and 11.3 (75.1) µg adult−1 on housefly females and males, respectively. All EOs were effective against S. littoralis larvae; LD50 values were 33.2–66.7 µg larva−1, and tepa EO was the most effective in terms of LD90 (i.e., <100 µg larva−1). Canelo, tepa, and paramela EOs were highly effective on C. quinquefasciatus larvae, with LC50 values < 100 µL L−1. Again, tepa EO achieved LD90 < 100 µL L−1. This EO was characterized by safrole (43.1%), linalool (27.9%), and methyl eugenol (6.9%) as major constituents. Overall, Patagonian native plant EOs can represent a valid resource for local stakeholders, to develop effective insecticides for pest and vector management, pending a proper focus on their formulation and nontarget effects

    Evaluation of Physicochemical and Microbial Properties of Extracts from Wine Lees Waste of Matelica’s Verdicchio and Their Applications in Novel Cosmetic Products

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    Wine lees are sediments deposited on the walls and bottom of barrels resulting from wine fermentation and mainly consist of yeasts. Saccharomyces cerevisiae extracts, rich in beneficial components for the skin, have already been used in cosmesis, while wine lees have not been well exploited by the cosmetics industry yet. The aim of this work was the full characterization of the wine lees from Verdicchio's wine, with the aim to exploit it as a beneficial ingredient in new cosmetic products. After mapping the microbial composition of the sample waste, the parameters for the sonication extraction process were optimized and the physicochemical properties of the extract were analyzed. The efficiency of the aqueous extraction-and in particular the yeast cell lysis necessary for the release of proteins from the cell-was assessed by evaluating cell shape and size, and protein release, under scanning electron microscopy (SEM), dynamic light scattering (DLS) and Bradford's protein assays. Thus, the total phenol content and antioxidant capacity of the supernatant recovered from native and sonicated lees were determined by Folin-Ciocalteu's and spectrophotometric assays, respectively. To quantify the heavy metals and highlight the presence of microelements beneficial for the skin, inductively coupled plasma-mass spectrometry (ICP-MS) was applied. In vitro metabolic activity and cytotoxicity were tested on both HaCat keratinocytes and human gingival fibroblasts, showing that wine lees are safe for skin's cells. The results show that sonicated lees appear to be more interesting than native ones as a consequence of the release of the active ingredients from the cells. Due to the high antioxidant capacity, content of beneficial elements for skin and an appropriate microbiologic profile, wine lees were included in five new solid cosmetic products and tested for challenge test, compatibility with human skin, sensory analysis, trans epidermal water loss (TEWL) and sebometry

    Clasificación de lagos someros pampeanos mediante imágenes Landsat<SUP>TM</SUP>

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    Under normal hydro-meteorological conditions, lagoons cover up to 2,000,000 of the pampas territory, distributed in more than 2,000 permanent lacunar bodies. They contribute significantly to the life quality of their inhabitants and they constitute a potential source of environmental, economic and recreational resources. Several studies in different lagoons in different temporal periods have been developed in the province of Buenos Aires. They responded in an optimum way to the original goals, but they are barely valid when looking for dynamic spatial and temporal patterns in the lagoons, involving the use of the support basin. The use of remote sensors has proved effective in collecting the information needed to evaluate the quality of water bodies, to allow the search of temporal and spatial patterns, and to link lagoon water quality data with the characteristics of land use. We propose a proce dure for previously normalized satelital image analysis that will allow a classification of the lagoons based on their optical properties, conditioned by the contents of suspended inorganic solid matter and algal biomass. The results will be compared to samples in the field and spatially extrapolated. They will be used to propose alternative management methods jointly with some local decision makers.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

    Clasificación de lagos someros pampeanos mediante imágenes Landsat<SUP>TM</SUP>

    No full text
    Under normal hydro-meteorological conditions, lagoons cover up to 2,000,000 of the pampas territory, distributed in more than 2,000 permanent lacunar bodies. They contribute significantly to the life quality of their inhabitants and they constitute a potential source of environmental, economic and recreational resources. Several studies in different lagoons in different temporal periods have been developed in the province of Buenos Aires. They responded in an optimum way to the original goals, but they are barely valid when looking for dynamic spatial and temporal patterns in the lagoons, involving the use of the support basin. The use of remote sensors has proved effective in collecting the information needed to evaluate the quality of water bodies, to allow the search of temporal and spatial patterns, and to link lagoon water quality data with the characteristics of land use. We propose a proce dure for previously normalized satelital image analysis that will allow a classification of the lagoons based on their optical properties, conditioned by the contents of suspended inorganic solid matter and algal biomass. The results will be compared to samples in the field and spatially extrapolated. They will be used to propose alternative management methods jointly with some local decision makers.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

    Nuclear accumulation of c-myc mRNA in phytohaemagglutinin-activated T lymphocytes treated with anti-HLA class I monoclonal antibody

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    Anti-HLA class I monoclonal antibody 01.65 inhibits the proliferative response of PHA-activated human T lymphocytes from peripheral blood mononuclear cells. The recruitment rate in the cell cycle is slack and the G1 and S phases are prolonged. Among the early events after PHA activation, only the calcium-dependent PKC activity appears to be modified: particulate PKC is completely depleted while cytosolic residual PKC is reduced by 80% after MAb 01.65 treatment. We have carried out in greater detail the study of c-myc gene regulation by MAb 01.65 and the results are as follows: (i) c-myc RNA transcription is normally initiated and finished, suggesting a post-transcriptional regulation of c-myc gene expression; (ii) no alteration in c-myc mRNA stability has been documented; (iii) steady-state levels of c-myc mRNA expression by Northern blot analysis and PCR amplification are decreased in the cytoplasmic compartment, while in the nuclear compartment they appear to be increased. Nuclear accumulation of mature mRNA after MAb 01.65 and PKC inhibitor (H7 and StSp) treatment appears to be the most probable mechanism involved. The possible implications of this are discussed

    Adaptative value of a PKC-PKI55 feedback loop of inhibition that prevents the kinase's deregulation.

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    A 168-bp amplification product was obtained in RT-PCR experiments using a degenerate oligonucleotide designed on a five-amino acid sequence of IN, a 7-kDa protein, previously characterized as a PKC inhibitor. It was included in the coding ORF of the 1530-bp-long IMAGE clone ID 38900 (accession numbers R51337 and R51448) that produces a translation product of 6.5 kDa. The translation of the ORF conceptual reading frame allowed the preparation of the synthetic protein PKI55, which was found to inhibit and degrade both untreated nPKC d isozymes and activated cPKC isozymes. The PKI55 gene is localized in chromosome 2q35. The Repeat Maskers output showed a 533-bp-long LTR32/ERVL segment that included the PKI55 coding sequence and a complete regulatory region. The coding sequence and the structure of PKI55 were detected in a brain cDNA of Macaca fascicularis (diverged from human lineages about 25 Myr ago). Three other human genes with over 60% identities with PKI55 were identified in three different loci (i.e., chromosomes 10, 15, and 20.) Synthesis of PKI55 was stimulated by PKC activation. A feedback loop of inhibition is established. When the PKCs are overactivated, PKI55 induces degradation of the enzyme and prevents the isozyme overexpression implicated in a number of important diseases including cancer, diabetes, and disorders of the immune system. The presence of the PKI55 sequence in Macaca fascicularis as well as in human chromosomes 10, 15, and 20 indicates a selective advantage for the PKI55 sequence and the adaptive value of the feedback mechanism

    Human-threatened ecosystem: new signs of groundwater connection between Yacyreta reservoir and Ibera wetland (South America)

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    Ibera wetland is one of the most pristine and singular ecosystems of South America. Satellite-derived thermal analysis of its lacustrine system supported the existence of a groundwater connection with the Yacyreta reservoir through basaltic fractures located along the ancient river bed of the Parana. The groundwater outflow would be located on the geological discontinuity of the eastern border of Ibera wetland, concretely around Laguna Ibera´ and Laguna Luna–Disparo. This new sign of connection comes on top of the hydrological signs which already exist. A call to prudence recommends not extending the recently projected increase of the water level of Yacyreta reservoir. Deeper hydrogeological studies should analyze the hypothesis emerged from this study before modifying the water level of Yacyreta
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