185 research outputs found

    A sea-bottom sampler that collects both water and sediment simultaneously

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    A simple sampler, assembled mainly from commercially available eq uipment, is described. It simultaneously collects water samples at 1, 2, 3, 4, 5, and 6 m above the sea floor and takes a short core at the same location

    Betalain rich functional extract with reduced salts and nitrate content from red beetroot (Beta vulgaris L.) using membrane separation technology

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    An initial laboratory-scale evaluation of separation characteristics of membranes with nominal molecular weight cut-offs (NMWCO) ranging from 30 kD down to 0.5 kD indicated effective separation of betalains in the 0.5 kD region. Subsequent pilot-level trials using 1 kD, loose reverse osmosis (LRO) and reverse osmosis (RO) spiral-wound membranes showed LRO membrane to be very efficient with up to 96% salt and 47% other dissolved solids removed while retaining majority of the pigment (∼98%) in the betalain rich extract (BRE). The total betalain content in the BRE increased up to 46%, the highest recovery reported so far at pilot scale level. Interestingly, more than 95% of the nitrates were removed from the BRE after the three diafiltrations. These studies indicate that membrane technology is the most efficient technique to produce BRE with highly reduced amounts of salts and nitrate content

    New strawberry breeding lines – enhanced phytochemical composition and bioaccessibility

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    Screening of phytochemicals has been of interest in strawberry genotypes as there is emerging evidence from epidemiological and clinical studies that consumption of phytochemical-rich strawberry cultivars may provide health benefits. The aim of the present study was (1) to quantify selected phytochemicals in new strawberry breeding lines (BL) and (2) to assess the in vitro bioaccessibility of phytochemicals as an initial measure to predict their bioavailability

    Timing of extension in the Pioneer metamorphic core complex with implications for the spatial-temporal pattern of Cenozoic extension and exhumation in the northern U.S. Cordillera

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    The Pioneer core complex (PCC) in central Idaho lies along a transition between Early Eocene and ca. 40 Ma core complexes to the north and south, respectively. Thus, the age of extensional development of the PCC is important in understanding the spatial-temporal patterns of core-complex development in the North American Cordillera. New results, including structural observations and U-Pb zircon (SHRIMP and ICPMS) geochronology, constrain the early extensional history of the footwall for the first time. High-temperature strain with a top-WNW shear-sense is pervasive throughout metamorphic rocks of the northwestern footwall. An isoclinally folded dike yields a crystallization age of ∼48-47 Ma, whereas a crosscutting dike yielded an age of 46 Ma. Metamorphic rocks are also intruded by the ∼50-48 Ma Pioneer intrusive suite (PIS), a W-dipping granodiorite sheet displaying a magmatic fabric. Northwest-trending lineations are locally visible and also defined by anisotropy of magnetic susceptibility, indicating that during emplacement, the PIS was undergoing similarly oriented extensional strain as the enclosing metamorphic rocks. Therefore, WNW-directed extension spanning this structural section occurred between ∼50 and 46 Ma. Following emplacement of crosscutting 46 Ma dikes, deformation was partitioned into the WNW-directed Wildhorse detachment. Motion on the detachment occurred between ∼38 and 33 Ma, as documented by previous 40Ar/ 39Ar thermochronology. It is not clear, however, whether extension was continuous through the interval between these two time periods. Although Early Eocene extension in the PCC was synchronous with extension in core complexes to the north, rates of footwall exhumation in central Idaho were much lower. This southward slowing is compatible with N-S differences in inferred subduction zone geometry/kinematics and in the internal character of the orogenic wedge

    Astaxanthin profiles and corresponding colour properties in Australian farmed black tiger prawn (Penaeus monodon) during frozen storage

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    The colour of commercial cooked black tiger prawns (Penaeus monodon) is a key quality requirement to ensure product is not rejected in wholesale markets. The colour, due to the carotenoid astaxanthin, can be impacted by frozen storage, but changes in colour or astaxanthin profile, during frozen storage, have not been studied in detail. Subsequently in this study, the aims were to define the astaxanthin (as cis, trans, mono-ester and di-ester forms) content, together with the colour properties, in both pleopods (legs) and abdominal segments. Changes in astaxanthin content and colour properties were further determined during frozen storage (−20°C). Total astaxanthin content was seen to decrease in all samples over time, with the rate of degradation being significantly greater (P < 0.05) in pleopods than abdomen. In both pleopods and abdomen, rate of degradation of esterified forms was significantly greater (P < 0.05) than non-esterified forms. Hue angle (increase), a* value (decrease) and L value (increase) were all seen to significantly change (P < 0.05) during storage, with changes being more prevalent in the pleopods. The pleopods are the key indicator of astaxanthin and colour loss in cooked black tiger prawns and preservation strategies are required to preserve astaxanthin and colour during frozen storage

    Effect of drying, storage temperature and air exposure on astaxanthin stability from Haematococcus pluvialis

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    Astaxanthin is a powerful antioxidant with various health benefits such as prevention of age-related macular degeneration and improvement of the immune system, liver and heart function. To improve the post-harvesting stability of astaxanthin used in food, feed and nutraceutical industries, the biomass of the high astaxanthin producing alga Haematococcus pluvialis was dried by spray- or freeze-drying and under vacuum or air at -20 degrees C to 37 degrees C for 20 weeks. Freeze-drying led to 41% higher astaxanthin recovery compared to commonly-used spray-drying. Low storage temperature (-20 degrees C, 4 degrees C) and vacuum-packing also showed higher astaxanthin stability with as little as 123 +/- 3.1% degradation during 20 weeks of storage. Cost-benefit analysis showed that freeze-drying followed by vacuum-packed storage at -20 degrees C can generate AUD$600 higher profit compared to spray-drying from 100 kg H. pluvialis powder. Therefore, freeze-drying can be suggested as a mild and more profitable method for ensuring longer shelf life of astaxanthin from H. pluvialis. (C) 2015 Elsevier Ltd. All rights reserved

    Interannual and Subdecadal Variability in the Nutrient Geochemistry of the Cariaco Basin

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    The CARIACO Ocean Time Series program has made monthly measurements of oxygen, nutrients, and carbon system parameters (∑CO2, alkalinity, pH) in the Cariaco Basin since 1996. At the same time, sediment traps have collected settling particles at four to five depths ranging from 150 to 1,200 m. The depth of the transition from oxic to anoxic conditions has fluctuated dramatically over the time series due to changes in the occurrence of Caribbean water intrusions into the deep basin. Nutrient concentrations in the deep basin have increased steadily with time in a proportion reflective of the elemental ratios in the settling organic matter, although N:P ratios in the water column (approximately 16:1) differ from ratios in the accumulating nutrients (11:1) and the settling flux (ranging between 5:1 and 12.5:1). This difference is likely due to changes in the source material for remineralization, either because of sizeable ecosystem changes or changes in the relative importance of the terrestrial input of inorganic P or scavenging of P by mineral precipitation near the oxic/anoxic interface. Alternatively, there may have been changes in the degree of preferential remineralization of P

    Συναρτήσεις Bessel

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    Consumption of anthocyanins from fruit sources may exert protection against hypertension and improve cognition. However, the effect of dose timing in studies is rarely considered. We hypothesized that timed-dose consumption of juice from an anthocyanin-rich Japanese plum variety (Queen Garnet plum, QGP) will have acute and dose-timing effects on cardiovascular responses, cognition, and urinary anthocyanin excretion profiles. Our study objective was to investigate the impact of plum juice on these health parameters. Twelve older (65+ years) and 12 younger (18-45 years) adults participated in an acute crossover study. Participants received, randomly, either 1 × 300 mL or 3 × 100 mL plum juice over 3 hours on 2 different occasions with a 2-week washout period. A battery of cognitive tasks was administered at 0 and 6 hours on each study day. Blood pressure (BP) and urinary anthocyanin/metabolite excretion profiles were measured over 24 hours. Area under the curve for BP was calculated (0-6 hours). A significant reduction in BP and cardiovascular responses was observed in both age groups which was more obvious in the older age group on the single dose for systolic BP, diastolic BP, mean arterial pressure, and heart rate (P values = .035, .028, .017, and .006, respectively). No significant difference was observed between dose-timing regimens for either age group. There was no observed effect on cognition. Native QGP anthocyanins, as well as methylated/glucuronidated metabolites, were detected in urine with no significant differences between age groups or dose timing. High-anthocyanin plum juice significantly reduced BP, but dose timing did not appear to be a significant factor in the potential acute BP-lowering effect of QGP juice

    Isolation and functional characterization of a lycopene β-cyclase gene that controls fruit colour of papaya (Carica papaya L.)

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    The colour of papaya fruit flesh is determined largely by the presence of carotenoid pigments. Red-fleshed papaya fruit contain lycopene, whilst this pigment is absent from yellow-fleshed fruit. The conversion of lycopene (red) to β-carotene (yellow) is catalysed by lycopene β-cyclase. This present study describes the cloning and functional characterization of two different genes encoding lycopene β-cyclases (lcy-β1 and lcy-β2) from red (Tainung) and yellow (Hybrid 1B) papaya cultivars. A mutation in the lcy-β2 gene, which inactivates enzyme activity, controls lycopene production in fruit and is responsible for the difference in carotenoid production between red and yellow-fleshed papaya fruit. The expression level of both lcy-β1 and lcy-β2 genes is similar and low in leaves, but lcy-β2 expression increases markedly in ripe fruit. Isolation of the lcy-β2 gene from papaya, that is preferentially expressed in fruit and is correlated with fruit colour, will facilitate marker-assisted breeding for fruit colour in papaya and should create possibilities for metabolic engineering of carotenoid production in papaya fruit to alter both colour and nutritional properties
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