391 research outputs found

    Quantitative trait loci conferring grain mineral nutrient concentrations in durum wheat 3 wild emmer wheat RIL population

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    Mineral nutrient malnutrition, and particularly deficiency in zinc and iron, afflicts over 3 billion people worldwide. Wild emmer wheat, Triticum turgidum ssp. dicoccoides, genepool harbors a rich allelic repertoire for mineral nutrients in the grain. The genetic and physiological basis of grain protein, micronutrients (zinc, iron, copper and manganese) and macronutrients (calcium, magnesium, potassium, phosphorus and sulfur) concentration was studied in tetraploid wheat population of 152 recombinant inbred lines (RILs), derived from a cross between durum wheat (cv. Langdon) and wild emmer (accession G18-16). Wide genetic variation was found among the RILs for all grain minerals, with considerable transgressive effect. A total of 82 QTLs were mapped for 10 minerals with LOD score range of 3.2–16.7. Most QTLs were in favor of the wild allele (50 QTLs). Fourteen pairs of QTLs for the same trait were mapped to seemingly homoeologous positions, reflecting synteny between the A and B genomes. Significant positive correlation was found between grain protein concentration (GPC), Zn, Fe and Cu, which was supported by significant overlap between the respective QTLs, suggesting common physiological and/or genetic factors controlling the concentrations of these mineral nutrients. Few genomic regions (chromosomes 2A, 5A, 6B and 7A) were found to harbor clusters of QTLs for GPC and other nutrients. These identified QTLs may facilitate the use of wild alleles for improving grain nutritional quality of elite wheat cultivars, especially in terms of protein, Zn and Fe

    Mapping quantitative trait loci (QTLs) associated with dough quality in a soft × hard bread wheat progeny

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    Bread wheat (Triticum aestivum L.) quality is a key trait for baking industry exigencies and broad consumer preferences. The main goal of this study was to undertake quantitative trait loci (QTL) analyses for bread wheat quality in a set of 79 recombinant inbred lines (RILs) derived from a soft × hard bread wheat cross. Field trials were conducted over two years, utilizing a randomized complete block design. Dough quality was evaluated by sedimentation test, mixograph and alveograph analysis. Protein content was measured by near-infrared reflectance analysis and grain hardness was determined by the single kernel characterization system (SKCS). A genetic map based on 263 SSR markers and glutenin loci was constructed. Composite interval mapping (CIM) analysis detected a total of 20 QTLs distributed among ten chromosomes which were associated with variations in quality traits. Results confirmed the previous investigations on the known relationship between storage-protein alleles and dough quality, and detected new and stable QTLs related to dough quality parameters on chromosomes 2A, 7A, 5B and 1D. These new QTLs could be further investigated. Also, in this study, some RILs showed very high dough extensibility values which involve future validation studies for QTLs associated with to this trait

    A case study of Kanban implementation within the Pharmaceutical Supply Chain

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    The paper explores the implementation of the kanban system, which is a Lean technique, within the Pharmaceutical Supply Chain (PSC). The case study provides insight to the benefits and challenges arising from the application of this technique, within a group of cooperative pharmacists, in Greece. The research questions developed from the review of the literature were tested using evidence from field-based, action research within a pharmaceutical organisation. The reported case study contributes to the longer term debate on assessing the Lean maturity level within the healthcare sector. There are two primary findings: i) that the adoption of kanban system provides a strategic benefit and improves the quality of services. ii) it also provides a basis for a strategy of operational change; it gives the opportunity to the organisation to move away from the current push delivery and logistics systems toward improved logistics strategy models

    BK Channels Regulate Spontaneous Action Potential Rhythmicity in the Suprachiasmatic Nucleus

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    Background: Circadian (,24 hr) rhythms are generated by the central pacemaker localized to the suprachiasmatic nucleus (SCN) of the hypothalamus. Although the basis for intrinsic rhythmicity is generally understood to rely on transcription factors encoded by ‘‘clock genes’’, less is known about the daily regulation of SCN neuronal activity patterns that communicate a circadian time signal to downstream behaviors and physiological systems. Action potentials in the SCN are necessary for the circadian timing of behavior, and individual SCN neurons modulate their spontaneous firing rate (SFR) over the daily cycle, suggesting that the circadian patterning of neuronal activity is necessary for normal behavioral rhythm expression. The BK K + channel plays an important role in suppressing spontaneous firing at night in SCN neurons. Deletion of the Kcnma1 gene, encoding the BK channel, causes degradation of circadian behavioral and physiological rhythms. Methodology/Principal Findings: To test the hypothesis that loss of robust behavioral rhythmicity in Kcnma1 2/2 mice is due to the disruption of SFR rhythms in the SCN, we used multi-electrode arrays to record extracellular action potentials from acute wild-type (WT) and Kcnma1 2/2 slices. Patterns of activity in the SCN were tracked simultaneously for up to 3 days, and the phase, period, and synchronization of SFR rhythms were examined. Loss of BK channels increased arrhythmicity but also altered the amplitude and period of rhythmic activity. Unexpectedly, Kcnma1 2/2 SCNs showed increased variability in the timing of the daily SFR peak

    Genetic Insight into Yield-Associated Traits of Wheat Grown in Multiple Rain-Fed Environments

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    Background: Grain yield is a key economic driver of successful wheat production. Due to its complex nature, little is known regarding its genetic control. The goal of this study was to identify important quantitative trait loci (QTL) directly and indirectly affecting grain yield using doubled haploid lines derived from a cross between Hanxuan 10 and Lumai 14. Methodology/Principal Findings: Ten yield-associated traits, including yield per plant (YP), number of spikes per plan

    Response of the Human Circadian System to Millisecond Flashes of Light

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    Ocular light sensitivity is the primary mechanism by which the central circadian clock, located in the suprachiasmatic nucleus (SCN), remains synchronized with the external geophysical day. This process is dependent on both the intensity and timing of the light exposure. Little is known about the impact of the duration of light exposure on the synchronization process in humans. In vitro and behavioral data, however, indicate the circadian clock in rodents can respond to sequences of millisecond light flashes. In a cross-over design, we tested the capacity of humans (n = 7) to respond to a sequence of 60 2-msec pulses of moderately bright light (473 lux) given over an hour during the night. Compared to a control dark exposure, after which there was a 3.5±7.3 min circadian phase delay, the millisecond light flashes delayed the circadian clock by 45±13 min (p<0.01). These light flashes also concomitantly increased subjective and objective alertness while suppressing delta and sigma activity (p<0.05) in the electroencephalogram (EEG). Our data indicate that phase shifting of the human circadian clock and immediate alerting effects can be observed in response to brief flashes of light. These data are consistent with the hypothesis that the circadian system can temporally integrate extraordinarily brief light exposures
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