218 research outputs found
Changes in quercetin and kaempferol concentrations during broccoli head ontogeny in three broccoli cultivars
Three broccoli cultivars – spear broccoli ‘Emperor’, crown broccoli ‘Marathon’ and violet broccoli ‘Viola’ – were harvested during head ontogeny from start of head development until over maturity stage (five stages) in three different years. The aglycones quercetin and kaempferol were analysed at optimised conditions of acid hydrolysis by HPLC. Heads of over maturity stage had the highest contents of quercetin and kaempferol. However, the genotype fundamentally determined the quantity and course of the increase in flavonols. Mini broccoli, as a new trend to market vegetables, has lower content of flavonols than the commercial stage, which indicates a reduction in health potentials. Harvesting broccoli heads of over maturity stage should be used as raw material, e.g. for the design of new functional foods
A surface-fitting program for areally- distributed data from the earth sciences and remote sensing
Fortran II program for analysis of data from earth sciences and remote sensin
The shape and erosion of pebbles
The shapes of flat pebbles may be characterized in terms of the statistical
distribution of curvatures measured along their contours. We illustrate this
new method for clay pebbles eroded in a controlled laboratory apparatus, and
also for naturally-occurring rip-up clasts formed and eroded in the Mont
St.-Michel bay. We find that the curvature distribution allows finer
discrimination than traditional measures of aspect ratios. Furthermore, it
connects to the microscopic action of erosion processes that are typically
faster at protruding regions of high curvature. We discuss in detail how the
curvature may be reliable deduced from digital photographs.Comment: 10 pages, 11 figure
The impact of inter‐flood duration on non‐cohesive sediment bed stability
© 2019 John Wiley & Sons, Ltd. Limited field and flume data suggests that both uniform and graded beds appear to progressively stabilize when subjected to inter-flood flows as characterized by the absence of active bedload transport. Previous work has shown that the degree of bed stabilization scales with duration of inter-flood flow, however, the sensitivity of this response to bed surface grain size distribution has not been explored. This article presents the first detailed comparison of the dependence of graded bed stability on inter-flood flow duration. Sixty discrete experiments, including repetitions, were undertaken using three grain size distributions of identical D50 (4.8 mm); near-uniform (σg = 1.13), unimodal (σg = 1.63) and bimodal (σg = 2.08). Each bed was conditioned for between 0 (benchmark) and 960 minutes by an antecedent shear stress below the entrainment threshold of the bed (τ*c50). The degree of bed stabilization was determined by measuring changes to critical entrainment thresholds and bedload flux characteristics. Results show that (i) increasing inter-flood duration from 0 to 960 minutes increases the average threshold shear stress of the D50 by up to 18%; (ii) bedload transport rates were reduced by up to 90% as inter-flood duration increased from 0 to 960 minutes; (iii) the rate of response to changes in inter-flood duration in both critical shear stress and bedload transport rate is non-linear and is inversely proportional to antecedent duration; (iv) there is a grade dependent response to changes in critical shear stress where the magnitude of response in uniform beds is up to twice that of the graded beds; and (v) there is a grade dependent response to changes in bedload transport rate where the bimodal bed is most responsive in terms of the magnitude of change. These advances underpin the development of more accurate predictions of both entrainment thresholds and bedload flux timing and magnitude, as well as having implications for the management of environmental flow design. © 2019 John Wiley & Sons, Ltd. © 2019 John Wiley & Sons, Ltd
What is in a pebble shape?
We propose to characterize the shapes of flat pebbles in terms of the
statistical distribution of curvatures measured along the pebble contour. This
is demonstrated for the erosion of clay pebbles in a controlled laboratory
apparatus. Photographs at various stages of erosion are analyzed, and compared
with two models. We find that the curvature distribution complements the usual
measurement of aspect ratio, and connects naturally to erosion processes that
are typically faster at protruding regions of high curvature.Comment: Phys. Rev. Lett. (to appear
Long-term postharvest aroma evolution of tomatoes with the alcobaça (alc) mutation
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. 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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
Mineralogy and chemistry of cobbles at Meridiani Planum, Mars, investigated by the Mars Exploration Rover Opportunity
Numerous loose rocks with dimensions of a few centimeters to tens of centimeters and with no obvious physical relationship to outcrop rocks have been observed along the traverse of the Mars Exploration Rover Opportunity. To date, about a dozen of these rocks have been analyzed with Opportunity’s contact instruments, providing information about elemental chemistry (Alpha Particle X‐ray Spectrometer), iron mineralogy and oxidation states (Mössbauer Spectrometer) and texture (Microscopic Imager). These “cobbles” appear to be impact related, and three distinct groups can be identified on the basis of chemistry and mineralogy. The first group comprises bright fragments of the sulfate‐rich bedrock that are compositionally and texturally indistinguishable from outcrop rocks. All other cobbles are dark and are divided into two groups, referred to as the “Barberton group” and the “Arkansas group,” after the first specimen of each that was encountered by Opportunity. Barberton group cobbles are interpreted as meteorites with an overall chemistry and mineralogy consistent with a mesosiderite silicate clast composition. Arkansas group cobbles appear to be related to Meridiani outcrop and contain an additional basaltic component. They have brecciated textures, pointing to an impact‐related origin during which local bedrock and basaltic material were mixed
A multidisciplinary approach to identify priority areas for the monitoring of a vulnerable family of fishes in Spanish Marine National Parks
Background
Syngnathid fishes (Actinopterygii, Syngnathidae) are flagship species strongly associated with seaweed and seagrass habitats. Seahorses and pipefishes are highly vulnerable to anthropogenic and environmental disturbances, but most species are currently Data Deficient according to the IUCN (2019), requiring more biological and ecological research. This study provides the first insights into syngnathid populations in the two marine Spanish National Parks (PNIA—Atlantic- and PNAC—Mediterranean). Fishes were collected periodically, marked, morphologically identified, analysed for size, weight, sex and sexual maturity, and sampled for stable isotope and genetic identification. Due the scarcity of previous information, habitat characteristics were also assessed in PNIA.
Results
Syngnathid diversity and abundance were low, with two species identified in PNIA (Hippocampus guttulatus and Syngnathus acus) and four in PNAC (S. abaster, S. acus, S. typhle and Nerophis maculatus). Syngnathids from both National Parks (NP) differed isotopically, with much lower δ15N in PNAC than in PNIA. The dominant species were S. abaster in PNAC and S. acus in PNIA. Syngnathids preferred less exposed sites in macroalgal assemblages in PNIA and Cymodocea meadows in PNAC. The occurrence of very large specimens, the absence of small-medium sizes and the isotopic comparison with a nearby population suggest that the population of Syngnathus acus (the dominant syngnathid in PNIA) mainly comprised breeders that migrate seasonally. Mitochondrial cytochrome b sequence variants were detected for H. guttulatus, S. acus, and S. abaster, and a novel 16S rDNA haplotype was obtained in N. maculatus. Our data suggest the presence of a cryptic divergent mitochondrial lineage of Syngnathus abaster species in PNAC.
Conclusions
This is the first multidisciplinary approach to the study of syngnathids in Spanish marine NPs. Habitat preferences and population characteristics in both NPs differed. Further studies are needed to assess the occurrence of a species complex for S. abaster, discarding potential misidentifications of genus Syngnathus in PNAC, and evaluate migratory events in PNIA. We propose several preferential sites in both NPs for future monitoring of syngnathid populations and some recommendations for their conservation.Postprin
Meteorites on Mars observed with the Mars Exploration Rovers
Reduced weathering rates due to the lack of liquid water and significantly greater typical surface ages should result in a higher density of meteorites on the surface of Mars compared to Earth. Several meteorites were identified among the rocks investigated during Opportunity’s traverse across the sandy Meridiani plains. Heat Shield Rock is a IAB iron meteorite and has been officially recognized as ‘‘Meridiani Planum.’’ Barberton is olivine-rich and contains metallic Fe in the form of kamacite, suggesting a meteoritic origin. It is chemically most consistent with a mesosiderite silicate clast. Santa Catarina is a brecciated rock with a chemical and mineralogical composition similar to Barberton. Barberton, Santa Catarina, and cobbles adjacent to Santa Catarina may be part of a strewn field. Spirit observed two probable iron meteorites from its Winter Haven location in the Columbia Hills in Gusev Crater. Chondrites have not been identified to date, which may be a result of their lower strengths and probability to survive impact at current atmospheric pressures. Impact craters directly associated with Heat Shield Rock, Barberton, or Santa Catarina have not been observed, but such craters could have been erased by eolian-driven erosion.Additional co-authors: DW Ming, RV Morris, PA de Souza Jr, SW Squyres, C Weitz, AS Yen, J Zipfel, T Economo
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