122 research outputs found

    The deuteron: structure and form factors

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    A brief review of the history of the discovery of the deuteron in provided. The current status of both experiment and theory for the elastic electron scattering is then presented.Comment: 80 pages, 33 figures, submited to Advances in Nuclear Physic

    Long-term postharvest aroma evolution of tomatoes with the alcobaça (alc) mutation

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    The postharvest evolution of Penjar tomatoes has been studied in four accessions representative of the variability of the varietal type. The long-term shelf life of these materials, which carry the alc allele, was confirmed with 31.2-59.1% of commercial fruits after 6 months of effective conservation at room temperature and a limited loss of weight (21.1-27.9%). Aroma in Penjar tomatoes is differentiated from other tomato varieties by a characteristic 'sharp-floral' aroma descriptor. The evolution of the 'sharp-floral' aroma during postharvest showed a peak of intensity at 2 months of postharvest, though in one accession a delay of 2 months in this response was detected. Out of 25 volatiles analysed, including main and background notes, a reverse iPLS variable selection revealed that the main candidates behind this aromatic behaviour are ¿-terpineol, trans-2-hexenal, 6-methyl-5-hepten-2-one, trans-2-octenal, ¿-pinene, ß-ionone, 2 + 3-methylbutanol and phenylacetaldehyde. Between harvest and 2 months postharvest, most compounds reduced considerably their concentration, while the intensity of the 'sharp-floral' descriptor increased, which means that probably there is a rearrangement of the relative concentrations among volatiles that may lead to masking/unmasking processes. © 2011 Springer-Verlag.This work was supported by grants from the Conselleria de Agricultura, Pesca y Alimentacio de la Comunidad Valenciana, the Fundacion de la Comunidad Valenciana para la Investigacion Agroalimentaria (AGROALIMED) and from the Departament d'Agricultura, Alimentacio i Accio Rural (DAR) de la Generalitat de Catalunya.Casals Missio, J.; Cebolla Cornejo, J.; Rosello Ripolles, S.; Beltran Arandes, J.; Casanas, F.; Nuez Viñals, F. (2011). Long-term postharvest aroma evolution of tomatoes with the alcobaça (alc) mutation. European Food Research and Technology. 233(2):331-342. doi:10.1007/s00217-011-1517-6S3313422332Petro-Turza M (1987) Flavor of tomato and tomato products. Food Rev Int 2:309–351Butterry RG (1993) Quantitative and sensory aspects of flavor of tomato and other vegetables and fruits. In: Acree TE, Teranishi R (eds) Flavor science: sensible principles and techniques. American Chemical Society, WashingtonGoff SA, Klee HJ (2006) Plant volatile compounds: sensory cues for health and nutritional value? Science 311:815–819Tieman DM, Zeigler M, Schmelz EA, Taylor MG, Bliss P, Kirst M, Klee MJ (2006) Identification of loci affecting flavour volatile emissions in tomato fruits. J Exp Bot 57:887–896Zanor MI, Rambla JL, Chaïb J, Steppa A, Medina A, Granell A, Fernie AR, Causse M (2009) Metabolic characterization of loci affecting sensory attributes allows an assessment of the influence of the levels of primary metabolites and volatile organic contents. J Exp Bot 60:2139–2154Ortiz-Serrano P, Gil JV (2010) Quantitative comparison of free and bound volatiles of two commercial tomato cultivars (Solanum lycopersicum L.) during ripening. J Agric Food Chem 58:1106–1114Boukobza F, Taylor AJ (2002) Effect of postharvest treatment on flavour volatiles of tomatoes. Postharvest Biol Technol 25:321–331Vrebalov J, Ruezinsky D, Padmanabhan V, White R, Medrano D, Drake R, Schuch W, Giovannoni J (2002) A MADS-box gene necessary for fruit ripening at the tomato ripening-inhibitor (rin) locus. Science 296:343–346Giovannoni JJ, Tanksley SD, Vrebalov J, Noensie E (2004) NOR gene for use in manipulation of fruit quality and ethylene response. US Patent No 5,234,834 issued 13 July 2004McGlasson WB, Last JH, Shaw KJ, Meldrum SK (1987) Influence of the non-ripening mutants rin and nor on the aroma of tomato fruit. HortScience 22:632–634Baldwin EA, Scott JW, Shewmaker CK, Schuch W (2000) Flavor trivia and tomato aroma: biochemistry and possible mechanisms for control of important aroma components. HortScience 35:1013–1022Kovács K, Rupert CF, Tikunov Y, Graham N, Bradley G, Seymour GB, Bovy AG, Grierson D (2009) Effect of pleiotropic ripening mutations on flavour volatile biosynthesis. Phytochemistry 70:1003–1008Gao HY, Zhu BZ, Zhu HL, Zhang YL, Xie YH, Li YC, Luo YB (2007) Effect of suppression of ethylene biosynthesis on flavour products in tomato fruits. Russ J Plant Physiol 54:80–88Lewinsohn E, Sitrit Y, Bar E, Azulay Y, Meir A, Zamir D, Tadmor Y (2005) Carotenoid pigmentation affects the volatile composition of tomato and watermelon fruits, as revealed by comparative genetic analyses. J Agric Food Chem 53:3142–3148Kopeliovitch E, Mizrahi Y, Rabinowitch D, Kedar N (1980) Physiology of the mutant alcobaca. Physiol Plant 48:307–311Casals J, Pacual L, Cañizares J, Cebolla-Cornejo J, Casañas F, Nuez F (2011) Genetic basis of long shelf life and variability into Penjar tomato. Genet Resour Crop Evol. doi: 10.1007/s10722-011-9677-6Kuzyomenskii AV (2007) Effect of cumulative polymery of tomato keeping life genes. Cytol Genet 41:268–275Paran I, van der Knaap E (2007) Genetic and molecular regulation of fruit and plant domestication traits in tomato and pepper. J Exp Bot 58:3841–3852Moretti CL, Baldwin EA, Sargent SA, Huber DJ (2002) Internal bruising alters aroma volatile profiles in tomato fruit tisúes. HortScience 37:378–382Buttery RG, Teranishi R, Ling LC (1987) Fresh tomato aroma volatiles: a qualitative study. J Agric Food Chem 35:540–544Romero del Castillo R, Valero J, Casañas F, Costell E (2008) Training validation and maintenance of a panel to evaluate the texture of dry beans (Phaseolus vulgaris L.). J Sens Stud 23:303–319Beltran J, Serrano E, López FJ, Peruga A, Valcárcel M, Roselló S (2006) Comparison of two quantitative GC-MS methods for analysis of tomato aroma based on purge-and-trap and on solid-phase microextraction. Anal Bioanal Chem 385:1255–1264Martens H, Naes T (1989) Multivariate Calibration. Wiley, New YorkWise BM, Gallagher NB, Bro R, Shaver JM, Windig W, Koch RS (2006) Chemometrics tutorial for PLS_Toolbox and Solo. Eigenvector Research, WenatcheeHongsoongnern P, Chambers E (2008) A lexicon for texture and flavor characteristics of fresh and processed tomatoes. J Sens Stud 23:583–599Norgaard L, Saudland A, Wagner J, Nielsen JP, Munck L, Engelsen SB (2000) Interval partial least-squares regression (iPLS): A comparative chemometric study with an example from near-infrared spectroscopy. Appl Spectrosc 54:413–419Javanmardi J, Kubota C (2006) Variation of lycopene, antioxidant activity, total soluble solids and weight loss of tomato during postharvest storage. Postharvest Biol Technol 41:151–155Kader AA (1986) Effects of postharvest handling procedures on tomato quality. Acta Hort 190:209–222Maul F, Sargent SA, Sims CA, Baldwin EA, Balaban MO, Huber DJ (2000) Tomato flavor and aroma quality as affected by storage temperature. J Food Sci 65:1228–1237Krumbein A, Auerswald H (1998) Characterization of aroma volatiles in tomatoes by sensory analyses. Nahrung 6:S395–S399Tandon KS, Baldwin EA, Shewfelt RL (2000) Aroma perception of individual volatile compounds in fresh tomatoes (Lycopersicon esculentum Mill.) as affected by the medium of evaluation. Postharvest Biol Technol 20:261–268Cebolla-Cornejo J, Roselló S, Valcárcel M, Serrano E, Beltran J, Nuez F (2011) Evaluation of genotype and environment effects on taste and aroma flavour components of Spanish fresh tomato varieties. J Agric Food Chem 59:2440–2450Carbonell-Barrachina AA, Agustí A, Ruiz JJ (2006) Analysis of flavor volatile compounds by dynamic headspace in traditional and hybrid cultivars of Spanish tomatoes. Eur Food Res Technol 222:536–542Alonso A, Vázquez-Araújo L, García-Martínez S, Ruiz JJ, Carbonell Barrachina AA (2009) Volatile compounds of traditional and virus-resistant breeding lines of Muchamiel tomatoes. Eur Food Res Technol 230:315–323Liggett E, Drake MA, Delwiche JF (2008) Impact of flavor attributes on consumer liking of Swiss cheese. J Dairy Sci 91:466–476Ortiz-Serrano P, Gil JV (2007) Quantitation of free and glycosidically bound volatiles in and effect of glycosidase addition on three tomato varieties (Solanum lycopersicum L.). J Agric Food Chem 55:9170–9176Xu Y, Barringer S (2010) Comparison of tomatillo and tomato volatile compounds in the headspace by selected ion flow tube mass spectrometry (SIFT-MS). J Food Sci 75:C268–C273Berna AZ, Lammertyn J, Saevels S, Di Natale C, Nicolai BM (2004) Electronic nose systems to study shelf life and cultivar effect on tomato aroma profile. Sens Actuators B Chem 97:324–333Baldwin EA, Scott JW, Einstein MA, Malundo TMM, Carr BT, Shewfelt RL, Tandon KS (1998) Relationship between sensory and instrumental analysis for tomato flavor. J Am Soc Hortic Sci 12:906–915Krumbein A, Peters P, Brückner B (2004) Flavour compounds and a quantitative descriptive analysis of tomatoes (Lycopersicon esculentum Mill.) of different cultivars in short-term storage. Postharvest Biol Technol 32:15–2

    The Aguablanca Ni–(Cu) sulfide deposit, SW Spain: geologic and geochemical controls and the relationship with a midcrustal layered mafic complex

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    The Aguablanca Ni–(Cu) sulfide deposit is hosted by a breccia pipe within a gabbro–diorite pluton. The deposit probably formed due to the disruption of a partially crystallized layered mafic complex at about 12– 19 km depth and the subsequent emplacement of melts and breccias at shallow levels (<2 km). The ore-hosting breccias are interpreted as fragments of an ultramafic cumulate, which were transported to the near surface along with a molten sulfide melt. Phlogopite Ar–Ar ages are 341– 332 Ma in the breccia pipe, and 338–334 Ma in the layered mafic complex, and are similar to recently reported U–Pb ages of the host Aguablanca Stock and other nearby calcalkaline metaluminous intrusions (ca. 350–330 Ma). Ore deposition resulted from the combination of two critical factors, the emplacement of a layered mafic complex deep in the continental crust and the development of small dilational structures along transcrustal strike-slip faults that triggered the forceful intrusion of magmas to shallow levels. The emplacement of basaltic magmas in the lower middle crust was accompanied by major interaction with the host rocks, immiscibility of a sulfide melt, and the formation of a magma chamber with ultramafic cumulates and sulfide melt at the bottom and a vertically zoned mafic to intermediate magmas above. Dismembered bodies of mafic/ultramafic rocks thought to be parts of the complex crop out about 50 km southwest of the deposit in a tectonically uplifted block (Cortegana Igneous Complex, Aracena Massif). Reactivation of Variscan structures that merged at the depth of the mafic complex led to sequential extraction of melts, cumulates, and sulfide magma. Lithogeochemistry and Sr and Nd isotope data of the Aguablanca Stock reflect the mixing from two distinct reservoirs, i.e., an evolved siliciclastic middle-upper continental crust and a primitive tholeiitic melt. Crustal contamination in the deep magma chamber was so intense that orthopyroxene replaced olivine as the main mineral phase controlling the early fractional crystallization of the melt. Geochemical evidence includes enrichment in SiO2 and incompatible elements, and Sr and Nd isotope compositions (87Sr/86Sri 0.708–0.710; 143Nd/144Ndi 0.512–0.513). However, rocks of the Cortegana Igneous Complex have low initial 87Sr/86Sr and high initial 143Nd/144Nd values suggesting contamination by lower crustal rocks. Comparison of the geochemical and geological features of igneous rocks in the Aguablanca deposit and the Cortegana Igneous Complex indicates that, although probably part of the same magmatic system, they are rather different and the rocks of the Cortegana Igneous Complex were not the direct source of the Aguablanca deposit. Crust–magma interaction was a complex process, and the generation of orebodies was controlled by local but highly variable factors. The model for the formation of the Aguablanca deposit presented in this study implies that dense sulfide melts can effectively travel long distances through the continental crust and that dilational zones within compressional belts can effectively focus such melt transport into shallow environments

    Influenza A Viruses from Wild Birds in Guatemala Belong to the North American Lineage

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    The role wild bird species play in the transmission and ecology of avian influenza virus (AIV) is well established; however, there are significant gaps in our understanding of the worldwide distribution of these viruses, specifically about the prevalence and/or significance of AIV in Central and South America. As part of an assessment of the ecology of AIV in Guatemala, we conducted active surveillance in wild birds on the Pacific and Atlantic coasts. Cloacal and tracheal swab samples taken from resident and migratory wild birds were collected from February 2007 to January 2010.1913 samples were collected and virus was detected by real time RT-PCR (rRT-PCR) in 28 swab samples from ducks (Anas discors). Virus isolation was attempted for these positive samples, and 15 isolates were obtained from the migratory duck species Blue-winged teal. The subtypes identified included H7N9, H11N2, H3N8, H5N3, H8N4, and H5N4. Phylogenetic analysis of the viral sequences revealed that AIV isolates are highly similar to viruses from the North American lineage suggesting that bird migration dictates the ecology of these viruses in the Guatemalan bird population

    The education effect: higher educational qualifications are robustly associated with beneficial personal and socio-political outcomes

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    Level of education is a predictor of a range of important outcomes, such as political interest and cynicism, social trust, health, well-being, and intergroup attitudes. We address a gap in the literature by analyzing the strength and stability of the education effect associated with this diverse range of outcomes across three surveys covering the period 1986–2011, including novel latent growth analyses of the stability of the education effect within the same individuals over time. Our analyses of the British Social Attitudes Survey, British Household Panel Survey, and International Social Survey Programme indicated that the education effect was robust across these outcomes and relatively stable over time, with higher education levels being associated with higher trust and political interest, better health and well-being, and with less political cynicism and less negative intergroup attitudes. The education effect was strongest when associated with political outcomes and attitudes towards immigrants, whereas it was weakest when associated with health and well-being. Most of the education effect appears to be due to the beneficial consequences of having a university education. Our results demonstrate that this beneficial education effect is also manifested in within-individual changes, with the education effect tending to become stronger as individuals age

    Complement system activation contributes to the ependymal damage induced by microbial neuraminidase

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    Background In the rat brain, a single intracerebroventricular injection of neuraminidase from Clostridium perfringens induces ependymal detachment and death. This injury occurs before the infiltration of inflammatory blood cells; some reports implicate the complement system as a cause of these injuries. Here, we set out to test the role of complement. Methods The assembly of the complement membrane attack complex on the ependymal epithelium of rats injected with neuraminidase was analyzed by immunohistochemistry. Complement activation, triggered by neuraminidase, and the participation of different activation pathways were analyzed by Western blot. In vitro studies used primary cultures of ependymal cells and explants of the septal ventricular wall. In these models, ependymal cells were exposed to neuraminidase in the presence or absence of complement, and their viability was assessed by observing beating of cilia or by trypan blue staining. The role of complement in ependymal damage induced by neuraminidase was analyzed in vivo in two rat models of complement blockade: systemic inhibition of C5 by using a function blocking antibody and testing in C6-deficient rats. Results The complement membrane attack complex immunolocalized on the ependymal surface in rats injected intracerebroventricularly with neuraminidase. C3 activation fragments were found in serum and cerebrospinal fluid of rats treated with neuraminidase, suggesting that neuraminidase itself activates complement. In ventricular wall explants and isolated ependymal cells, treatment with neuraminidase alone induced ependymal cell death; however, the addition of complement caused increased cell death and disorganization of the ependymal epithelium. In rats treated with anti-C5 and in C6-deficient rats, intracerebroventricular injection of neuraminidase provoked reduced ependymal alterations compared to non-treated or control rats. Immunohistochemistry confirmed the absence of membrane attack complex on the ependymal surfaces of neuraminidase-exposed rats treated with anti-C5 or deficient in C6. Conclusions These results demonstrate that the complement system contributes to ependymal damage and death caused by neuraminidase. However, neuraminidase alone can induce moderate ependymal damage without the aid of complement

    MAPK pathway activation in pilocytic astrocytoma

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    Pilocytic astrocytoma (PA) is the most common tumor of the pediatric central nervous system (CNS). A body of research over recent years has demonstrated a key role for mitogen-activated protein kinase (MAPK) pathway signaling in the development and behavior of PAs. Several mechanisms lead to activation of this pathway in PA, mostly in a mutually exclusive manner, with constitutive BRAF kinase activation subsequent to gene fusion being the most frequent. The high specificity of this fusion to PA when compared with other CNS tumors has diagnostic utility. In addition, the frequency of alteration of this key pathway provides an opportunity for molecularly targeted therapy in this tumor. Here, we review the current knowledge on mechanisms of MAPK activation in PA and some of the downstream consequences of this activation, which are now starting to be elucidated both in vitro and in vivo, as well as clinical considerations and possible future directions

    Worthy to Lose Some Money for Better Air Quality: Applications of Bayesian Networks on the Causal Effect of Income and Air Pollution on Life Satisfaction in Switzerland

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    One important determinant of well-being is the environmental quality. Many countries apply environmental regulations, reforms and policies for its improvement. However, the question is how the people value the environment, including the air quality. This study examines the association between air pollution and life satisfaction using the Swiss Household Panel survey over the years 2000–2013. We follow a Bayesian network (BN) strategy to estimate the causal effect of the income and air pollution on life satisfaction. We look at five main air pollutants: the ground-level ozone (O3), sulphur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO) and particulate matter of 10 micrometres (PM10). Then, we calculate the individuals’ marginal willingness to pay (MWTP) of reducing air pollution that aims to improve their life satisfaction. Beside the BN model, we take advantage of the panel structure of our data and we follow two approaches as robustness check. This includes the adapted probit fixed effects and the generalised methods of moments system. Our findings show that O3 and PM10 present the highest MWTP values ranging between 8000and8000 and 12,000, followed by the remained air pollutants with MWTP extending between 2000and2000 and 6500. Applying the BNs, we find that the causal effect of income on life satisfaction is substantially increased. We also show the causal effects of air pollutants remain almost the same, leading to lower values of willingness to pay
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