47 research outputs found

    Post-harvest quality of fresh-marketed tomatoes as a function of harvest periods

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    Losses on tomato business chain start at harvest, a two-months period. At the beginning of the harvest, fruits concentrate at the basal part of the plant, then in the middle, and finally at the top, and undergo changes in diameter and maturity indexes as harvest progresses. The aim of this work was to evaluate the impact of handling at three different periods: (I) 15 days, (II) 30 days, and (III) 45 days after the beginning of harvest. Tomatoes were ordinarily grown and harvested in to bamboo baskets, and transferred to plastics boxes. Fruits were classified according to ripening stage and diameter, and evaluated for mechanical damage and external defects caused by harvesting procedures. The time required for the harvest operation was measured; damage to fruits (%) and weight loss (%), caused either in the field and/or during the harvesting process, were taken into consideration and related to the final quality of fruit after storage for 21 days. The same methodology was used all through the production and harvest cycle. The highest % fruit damage occurred during period II, a longer harvest time than the other two periods. Fruits not submitted to handling showed lower weight loss than handled fruits. Fruits harvested in period II and stored for 21 days showed higher losses due to mechanical injury

    Deriving Global OH Abundance and Atmospheric Lifetimes for Long-Lived Gases: A Search for CH 3 CCl 3 Alternatives

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    An accurate estimate of global hydroxyl radical (OH) abundance is important for projections of air quality, climate, and stratospheric ozone recovery. As the atmospheric mixing ratios of methyl chloroform (CH₃CCl₃) (MCF), the commonly used OH reference gas, approaches zero, it is important to find alternative approaches to infer atmospheric OH abundance and variability. The lack of global bottom‐up emission inventories is the primary obstacle in choosing a MCF alternative. We illustrate that global emissions of long‐lived trace gases can be inferred from their observed mixing ratio differences between the Northern Hemisphere (NH) and Southern Hemisphere (SH), given realistic estimates of their NH‐SH exchange time, the emission partitioning between the two hemispheres, and the NH versus SH OH abundance ratio. Using the observed long‐term trend and emissions derived from the measured hemispheric gradient, the combination of HFC‐32 (CH₂F₂), HFC‐134a (CH₂FCF₃, HFC‐152a (CH₃CHF₂), and HCFC‐22 (CHClF₂), instead of a single gas, will be useful as a MCF alternative to infer global and hemispheric OH abundance and trace gas lifetimes. The primary assumption on which this multispecies approach relies is that the OH lifetimes can be estimated by scaling the thermal reaction rates of a reference gas at 272 K on global and hemispheric scales. Thus, the derived hemispheric and global OH estimates are forced to reconcile the observed trends and gradient for all four compounds simultaneously. However, currently, observations of these gases from the surface networks do not provide more accurate OH abundance estimate than that from MCF

    Phase Behavior of Aqueous Na-K-Mg-Ca-CI-NO3 Mixtures: Isopiestic Measurements and Thermodynamic Modeling

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    A comprehensive model has been established for calculating thermodynamic properties of multicomponent aqueous systems containing the Na{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, Cl{sup -}, and NO{sub 3}{sup -} ions. The thermodynamic framework is based on a previously developed model for mixed-solvent electrolyte solutions. The framework has been designed to reproduce the properties of salt solutions at temperatures ranging from the freezing point to 300 C and concentrations ranging from infinite dilution to the fused salt limit. The model has been parameterized using a combination of an extensive literature database and new isopiestic measurements for thirteen salt mixtures at 140 C. The measurements have been performed using Oak Ridge National Laboratory's (ORNL) previously designed gravimetric isopiestic apparatus, which makes it possible to detect solid phase precipitation. Water activities are reported for mixtures with a fixed ratio of salts as a function of the total apparent salt mole fraction. The isopiestic measurements reported here simultaneously reflect two fundamental properties of the system, i.e., the activity of water as a function of solution concentration and the occurrence of solid-liquid transitions. The thermodynamic model accurately reproduces the new isopiestic data as well as literature data for binary, ternary and higher-order subsystems. Because of its high accuracy in calculating vapor-liquid and solid-liquid equilibria, the model is suitable for studying deliquescence behavior of multicomponent salt systems

    Intracellular trafficking pathway of newly synthesized CD1b molecules

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    The intracellular trafficking of major histocompatibility complex (MHC) class I and class II molecules has evolved to support their function in peptide antigen presentation optimally. We have analyzed the intracellular trafficking of newly synthesized human CD1b, a lipid antigen-presenting molecule, to understand how this relates to its antigen-presenting function. Nascent CD1b was transported rapidly to the cell surface after leaving the Golgi, and then entered the endocytic system by internalization via AP-2-dependent sorting at the plasma membrane. A second sorting event, possibly involving AP-3 complexes, led to prominent accumulation of CD1b in MHC class II compartments (MIICs). Functional studies demonstrated the importance of nascent CD1b for the efficient presentation of a foreign lipid antigen. Therefore, the intracellular trafficking of nascent CD1b via the cell surface to reach MIICs may allow the efficient sampling of lipid antigens present in endocytic compartments

    Zoologia neocaledonica : 8. Biodiversity studies in New Caledonia

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    Les scinques du genre Sigaloseps sont rĂ©visĂ©s Ă  la lumiĂšre des informations obtenues Ă  partir des collections rĂ©alisĂ©es ces dix derniĂšres annĂ©es. Les rĂ©sultats du terrain, des Ă©tudes morphologiques et de la gĂ©nĂ©tique mettent en Ă©vidence un complexe de trois taxons autrefois confondus sous le binĂŽme Sigaloseps deplanchei, deux taxons identifiĂ©s comme Sigaloseps ruficauda et une autre espĂšce sans affinitĂ©s morphologiques apparentes avec un autre taxon dĂ©crit. Toutes les espĂšces sont restreintes Ă  des habitats situĂ©s sur des substrats ultramafiques du sud de la Nouvelle-CalĂ©donie. Dans notre analyse gĂ©nĂ©tique, trois taxons constituent un groupe bien individualisĂ© limitĂ© Ă  des habitats de zones d'altitude dans les massifs du sud. La spĂ©ciation Ă  l'intĂ©rieur de ce groupe reflĂšte probablement les contractions de la forĂȘt vers des refuges au sommet des montagnes liĂ©es aux changements climatiques qui se sont dĂ©roulĂ©s durant l'histoire ancienne et rĂ©cente du genre. Leur rĂ©partition gĂ©ographique extrĂȘmement Ă©troite et la vulnĂ©rabilitĂ© de leurs habitats prĂ©fĂ©rentiels par le feu (perte ou dĂ©gradation) et les espĂšces invasives rendent ces espĂšces d'altitude menacĂ©es et nous amĂšnent Ă  les ranger dans la catĂ©gorie 'VulnĂ©rable' selon les critĂšres de l'UICN. La nouvelle espĂšce dĂ©crite de la bordure nord de la rĂ©gion ultramafique du sud est connue seulement de deux localitĂ©s, toutes deux menacĂ©es, et a Ă©tĂ© rangĂ©e dans la catĂ©gorie UICN 'En danger'. La forme rĂ©visĂ©e de Sigaloseps deplanchei, Ă  prĂ©sent restreinte principalement Ă  la Grande Sud du sud de la Nouvelle-CalĂ©donie, prĂ©sente une sous-structuration gĂ©nĂ©tique intra-spĂ©cifique rĂ©gionale significative mais discrĂšte. Une ou plusieurs populations de chaque sous-groupe de Sigaloseps deplanchei sont reprĂ©sentĂ©es dans des rĂ©serves naturelles provinciales, mais la majoritĂ© de la rĂ©partition gĂ©ographique de chaque sous-groupe est vraisemblablement localisĂ©e dans des zones qui sont actuellement exploitĂ©es pour le nickel ou qui se situent dans des zones sous concession miniĂšre

    The (over)use of SMART goals for physical activity promotion: A narrative review and critique

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    The SMART acronym (e.g., Specific, Measurable, Achievable, Realistic, Timebound) is a highly prominent strategy for setting physical activity goals. While it is intuitive, and its practical value has been recognised, the scientific underpinnings of the SMART acronym are less clear. Therefore, we aimed to narratively review and critically examine the scientific underpinnings of the SMART acronym and its application in physical activity promotion. Specifically, our review suggests that the SMART acronym: is not based on scientific theory; is not consistent with empirical evidence; does not consider what type of goal is set; is not applied consistently; is lacking detailed guidance; has redundancy in its criteria; is not being used as originally intended; and has a risk of potentially harmful effects. These issues are likely leading to sub-optimal outcomes, confusion, and inconsistency. Recommendations are provided to guide the field towards better practice and, ultimately, more effective goal setting interventions to help individuals become physically active
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