3,176 research outputs found

    Estudio de los compuestos volátiles de diferentes especies de setas silvestres

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    Las setas son hongos macroscópicos poseedores de un cuerpo fructífero productor de esporas; no poseen clorofila pero si quitina. Las diferentes estructuras que estas pueden adoptar hacen que exista una amplia diversidad en función de la lámina, sombrero y pie que manifiesten. En el presente trabajo se han estudiado los compuestos orgánicos volátiles de seis especies de setas: Leccinum quercinum, Boletus edulis, Boletus phinophilus, Amanita ovoidea y Amanita rubescens recogidas en la Comunidad de Castilla y León. Su identificación se llevó a cabo mediante cromatografía de gases acoplada a un espectrómetro de masas. El número total de compuestos orgánicos volátiles detectados en las setas fue de 142. Los volátiles fueron agrupados en once familias según su estructura química: aldehídos de cadena lineal, aldehídos de cadena metil ramificada, cetonas alifáticas, alcoholes alifáticos, hidrocarburos alifáticos, compuestos bencénicos, ácidos y ésteres alifáticos, compuestos furánicos y furfurales, compuestos azufrados, terpenoides y compuestos nitrogenados. En la categoría denominada “desconocidos” se incluyen aquellos compuestos orgánicos volátiles cuya identificación no fue posible debido a que eluían compuestos insuficientemente separados o su espectro de masas no estaba en la base de datos y no pudo ser interpretado. El compuesto más abundante en los Boletus fue el 1-octen-3-ol, siendo el Leccinum quercinum la seta que presentó mayor concentración de ese compuesto. En las Amanitas el volátil más característico fue el benzaldehído; siendo la Amanita ovoidea la seta que presentó mayor concentración de este volátil. Debido a las elevadas concentraciones del 1-octen-3-ol y el benzaldehído en los Boletus y Amanitas respectivamente, podríamos concluir que esos compuestos podrían ser utilizados como posibles biomarcadores a la hora de diferenciar entre géneros y especies de setas, concretamente entre las especies de Boletus y de Amanitas.Grado en Nutrición Humana y Dietétic

    Understanding luxury fashion products consumption in retail outlets: a perspective of Portuguese women

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    The consumption of luxury fashion products has been undertaking a very powerful position in the consumers’ purchasing behaviours, as luxury products establish emotional connections with consumers, mostly with women, that goes beyond the utilitarian benefits. Furthermore, the presence of luxury fashion brands in retail outlets bring new insights towards the luxury fashion world, which have an impact in the consumers’ perceptions of brands. Accordingly, it is necessary to create an understanding of luxury fashion products consumption in retail outlets, through a female perspective, in order to generate valuable inputs that mean to comprehend consumers and support luxury brands. Therefore, the objectives of this dissertation are divided into three different courses. Firstly, it aims to understand the motivations behind the ideal luxury fashion purchase, as well as the motivations behind the real luxury fashion purchase in outlets stores. Secondly, it means to define the ideal luxury store environment, to analyse the real luxury outlet store environment, and finally, to recognize the importance of the atmosphere in luxury outlet stores. Lastly, it intends to investigate how luxury outlet stores influence the positioning of luxury brands. To accomplish the objectives defined, an exploratory qualitative research was conducted, in which were only interviewed Portuguese female consumers of luxury fashion products. The results proved that the motivations behind the consumption of luxury fashion products in retail outlets are primarily functional, and that the real store atmosphere of a luxury outlet store does not correspond with the ideal luxury store atmosphere, and that the consumers’ perceptions on the presence of luxury brands in outlets were inconsistent, and thus, benefits and disadvantages were retained.O consumo de produtos de marcas de luxo, na indústria da moda, tem vindo a assumir uma posição bastante importante no comportamento dos consumidores. Os produtos de luxo estabelecem conexões emocionais com os consumidores, que são maioritariamente mulheres, que se estendem para além dos seus benefícios utilitários. Além disso, a presença de marcas de luxo em retalhistas de outlet trazem novas perspetivas em relação ao mundo das marcas de luxo de moda, que afetam as perceções dos consumidores em relação às mesmas. Deste modo, é necessário criar um entendimento relativo ao consumo de marcas de luxo em outlets, através de uma perspetiva feminina, com o propósito de melhor compreender os consumidores e o desenvolvimento das marcas de luxo. Assim, os objetivos desta dissertação estão divididos em três partes. Primeiramente, tem por objetivo compreender as motivações dos consumidores em relação à compra ideal de produtos de luxo, e à compra real de produtos de luxo em outlet. De seguida, pretende definir o ambiente ideal das lojas de luxo, analisar o ambiente real das lojas de luxo em outlet, e de reconhecer a importância da atmosfera em lojas de luxo em outlet. Por fim, examina a forma como as lojas de luxo em outlet influenciam o posicionamento das respetivas marcas. De forma a poder cumprir com os objetivos propostos, foi efetuada uma análise exploratória qualitativa, na qual foram entrevistados apenas consumidores de marcas de luxo do género feminino e de nacionalidade Portuguesa. Os resultados do estudo provaram que as motivações dos consumidores para a compra de produtos de luxo em outlet são principalmente funcionais, que a atmosfera real de uma loja de luxo em outlet não corresponde à atmosfera ideal, e que as perceções dos consumidores relativamente à presença de marcas de luxo em outlets são inconsistentes, apresentando benefícios e desvantagens

    Herbivory by Lizards

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    The extent of herbivory in lizards is influenced by several factors. Plant tissues are more difficult to digest than invertebrates due to the presence of cellulose. Thus, so many lizards exhibit carnivorous diet. Nevertheless, some species consume vegetables. Essentially herbivorous diet occurs in about 3% of lizards, while most omnivores add plants in their diets. Omnivorous species tend to eat more fruits, flower, and nectar, because they are easier to digest and provide more nutrients than leaves, which are rich in cellulose. The main factors influencing the consumption of plant material are related to the habitat of the species. Insular and arid environments favor the consumption of plants because such locations have low amount of arthropods available and present water scarcity. It is also possible to observe ontogenetic changes in the lizard\u27s diet, in such a way that young individuals consume only invertebrates, whereas the adults supplement their diet with plant material. When consuming fruits and nectar, lizards become potential dispersers and pollinators. In this sense, some studies have already corroborated seed dispersal and pollination events by lizards. In islands where other species are absent, these interactions are essential for the maintenance of communities

    Neural network approach for estimating biophysical attributes during vegetative stages of potential canopies of maize in southeastern of Buenos Aires, Argentina

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    Leaf Area Index (LAI) is a key input for many crop models. The LAI patterns measured in situ are time consuming and labor intensive and could be substituted by intelligent techniques of approximation as artificial neural networks (ANNs). The objective of this study was to evaluate the possibility to estimate the evolution of LAI and height of maize canopies in southeastern of Buenos Aires Province, Argentine using neural network models. A field experiment under non limiting condition was carried out to generate a range of environmental conditions (four planting dates and three hybrids with contrasting maturity). Periodical measurements of LAI on tagged plants were used to develop, evaluate and test the neural networks to approximate variation of leaf area index and height at plot scale. Data from canopy structure properties as leaf area, height and leaf area density profile were obtained by non-destructive methods. Planting date (PD), relative maturity of the hybrid (MR) and thermal time from emergence (TTE) were the inputs to the ANNs. A decomposition method based on Garson’s algorithm was applied to quantify the relative importance for each input variable. The method provides a better description of the knowledge learned by the networks during the training process. Sensitivity analysis was performed to identify relevant variables and quantify the risk of a given combination of variables. The RM showed a major contribution in ANNs to estimate LAI and HLL. Both trained ANNs were most sensitive to TTE than the remaining inputs.Sociedad Argentina de Informática e Investigación Operativa (SADIO

    Neural network approach for estimating biophysical attributes during vegetative stages of potential canopies of maize in southeastern of Buenos Aires, Argentina

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    Leaf Area Index (LAI) is a key input for many crop models. The LAI patterns measured in situ are time consuming and labor intensive and could be substituted by intelligent techniques of approximation as artificial neural networks (ANNs). The objective of this study was to evaluate the possibility to estimate the evolution of LAI and height of maize canopies in southeastern of Buenos Aires Province, Argentine using neural network models. A field experiment under non limiting condition was carried out to generate a range of environmental conditions (four planting dates and three hybrids with contrasting maturity). Periodical measurements of LAI on tagged plants were used to develop, evaluate and test the neural networks to approximate variation of leaf area index and height at plot scale. Data from canopy structure properties as leaf area, height and leaf area density profile were obtained by non-destructive methods. Planting date (PD), relative maturity of the hybrid (MR) and thermal time from emergence (TTE) were the inputs to the ANNs. A decomposition method based on Garson’s algorithm was applied to quantify the relative importance for each input variable. The method provides a better description of the knowledge learned by the networks during the training process. Sensitivity analysis was performed to identify relevant variables and quantify the risk of a given combination of variables. The RM showed a major contribution in ANNs to estimate LAI and HLL. Both trained ANNs were most sensitive to TTE than the remaining inputs.Sociedad Argentina de Informática e Investigación Operativa (SADIO

    Developmental synaptic changes at the transient olivocochlear-inner hair cell synapse

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    In the mature mammalian cochlea, inner hair cells (IHCs) are mainly innervated by afferent fibers that convey sound information to the CNS. During postnatal development, however, medial olivocochlear (MOC) efferent fibers transiently innervate the IHCs. The MOC-IHC synapse, functional from postnatal day 0 (P0) to hearing onset (P12), undergoes dramatic changes in the sensitivity to acetylcholine (ACh) and in the expression of key postsynaptic proteins. To evaluate whether there are associated changes in the properties of ACh release during this period, we used a cochlear preparation from mice of either sex at P4, P6-P7, and P9-P11 and monitored transmitter release from MOC terminals in voltage-clamped IHCs in the whole-cell configuration. The quantum content increased 5.6× from P4 to P9-P11 due to increases in the size and replenishment rate of the readily releasable pool of synaptic vesicles without changes in their probability of release or quantum size. This strengthening in transmission was accompanied by changes in short-term plasticity properties, which switched from facilitation at P4 to depression at P9-P11. We have previously shown that at P9-P11, ACh release is supported by P/Q- and N-type voltage-gated calcium channels (VGCCs) and negatively regulated by BK potassium channels activated by Ca2+ influx through L-type VGCCs. We now show that at P4 and P6-P7, release is mediated by P/Q-, R- and L-type VGCCs. Interestingly, L-type VGCCs have a dual role: they both support release and fuel BK channels, suggesting that at immature stages presynaptic proteins involved in release are less compartmentalized.Fil: Kearney, Graciela Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Zorrilla de San Martín, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Vattino, Lucas Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Elgoyhen, Ana Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia; ArgentinaFil: Wedemeyer, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Katz, Eleonora. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin

    Reducing the occurrence of late BabyNet eligibility determinations using metrics based process improvement

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    This project explores the effort to decrease the number of eligibility decisions that exceed the time limit requirement, to strengthen the culture of the BabyNet team, and to conduct an analysis of the current work process cycle time gaps in present and past timelines, potential reasons for constrictions in the processes, and analysis of areas historically meeting the timeframes

    Field-induced Conductance Switching by Charge-state Alternation in Organometallic Single-Molecule Junctions

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    Charge transport through single molecules can be influenced by the charge and spin states of redox-active metal centres placed in the transport pathway. These molecular intrinsic properties are usually addressed by varying the molecules electrochemical and magnetic environment, a procedure that requires complex setups with multiple terminals. Here we show that oxidation and reduction of organometallic compounds containing either Fe, Ru or Mo centres can solely be triggered by the electric field applied to a two-terminal molecular junction. Whereas all compounds exhibit bias-dependent hysteresis, the Mo-containing compound additionally shows an abrupt voltage-induced conductance switching, yielding high to low current ratios exceeding 1000 at voltage stimuli of less than 1.0 V. DFT calculations identify a localized, redox active molecular orbital that is weakly coupled to the electrodes and closely aligned with the Fermi energy of the leads because of the spin-polarised ground state unique to the Mo centre. This situation opens an additional slow and incoherent hopping channel for transport, triggering a transient charging effect of the entire molecule and a strong hysteresis with unprecedented high low-to-high current ratios.Comment: 9 pages, 4 figure

    Spatial distribution and tree cover of hillside and ravine forests in Uruguay: the challenges of mapping patchy ecosystems

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    The mapping and monitoring of forest ecosystems on a national scale is key to their management and conservation. Native forests in Uruguay are considered given their importance for biodiversity and ecosystem services. Here we evaluate the spatial distribution of the land cover class ‘hillside and ravine forest’ —a subclass of native forest characterized by patches and transition zones with native grasslands— using Landsat images (30 x 30 m) from 2014 and 2015 and high-resolution images from Google Earth. To evaluate spatial heterogeneity within hillside forests, we then used highresolution SPOT images of 1 km2 from 1998-2012 to evaluate differences in the normalized difference vegetation index (NDVI) among canopy coverage categories. The hillside and ravine forest class were characterized as a composite cover class with an average canopy coverage of 69 ± 23%, variability of wich was reflected in NDVI values. The total area of this class in 2015 was estimated as 334,480 ha, somewhat less than an earlier 2008 estimate (384,240 ha). Among the potential errors in delineating hillside forests using Landsat images, there was the classification of «forest» in areas characterized by grassland and a tree canopy cover <25 %. This potential error in delimitation at broader scales led to the overestimation of hillside and ravine forest area in southeastern Uruguay, but an underestimation in northern Uruguay. Our study highlights the large discrepancies in the estimation of the distribution of hillside and ravine forest at different spatial scales, and also indicates the potential of NDVI to evaluate the heterogeneity of this forest within the same cover class

    Determination of calcium, magnesium, and aluminum in Fraser fir (Abies fraseri) foliage and surrounding soil in the Great Smoky Mountains, Balsam Mountains, and Black Mountains using inductively-coupled plasma optical emission spectroscopy

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    The Fraser fir (Abies Fraseri) is a conifer commonly found in the Eastern United States. In the Southern Appalachian Mountains Fraser fir share an ecosystem with Red Spruce (Picea rubens) in island-like stands typically above 1500 m. The Balsam Wooly Adelgid is recognized to be the primary reason for Fraser fir decline in the Southern Appalachian Mountains, but atmospheric deposition may also be involved. Acid deposition allows nutrients calcium (Ca2+) and magnesium (Mg2+) to be leached from soil and foliage, and allows for mobilization of toxic metals like aluminum (Al3+) to become available for interaction with the fir. Investigation of these effects could summarize the intensity of acidic deposition in the Southern Appalachian Mountain ranges studied. Samples of Fraser fir foliage and surrounding soil were gathered from 8 sites in the Great Smoky Mountains, in the Balsam Mountains, and in the Black Mountains. 30 samples were collected from each site, divided into 3 classes of life stage (10 seedlings, 10 saplings, and 10 mature trees). Using an acid digestion method for foliage and a soil extraction method for exchangeable metals in soil, concentrations of calcium, magnesium, and aluminum were found using Inductively-Coupled Plasma Optical Emission Spectroscopy. Student's t-test, analysis of variance, and linear regression analysis were used to statistically compare the data. There was a considerable amount of correlation between foliar and exchangeable soil metal concentrations as a result of elevation or longitude. The 8 sites were divided in half based on elevation (4 sites above 1900 m, 4 sites below 1900 m), and comparisons were made. Western sites are closer in proximity to coal-burning power plants in Tennessee, so they were expected to exhibit increased effects of acid deposition. Foliar and exchangeable soil metal concentrations were tested against soil pH, and very little correlation was found. Three life stage classes of samples were acquired (seedlings, saplings, and mature trees) and expected to all have statistically similar concentrations of metals in both foliage and soil, but almost all were different. No correlation was found in soil exchangeable metal concentrations and foliar metal concentrations, but a trend existed in soil exchangeable aluminum and foliar calcium concentrations. The data from this experiment was also compared to previous studies from 1969, 1994, and 1996 at two different sites. The comparison to the 1996 study at Clingmans Dome showed differences in foliar magnesium and aluminum concentrations, with decreased toxic metal and increased nutrient concentrations as expected. Differences also existed when comparing foliar nutrient concentrations to the 1969 and 1994 studies at Richland Balsam. Since 1994, a decline in acid deposition related effects was observed, which could show success of the 1990 Clean Air Act Amendments
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