494 research outputs found

    Análisis de diversidad genética y secuencias de nucleótidos del marcador mildi polvoso y del gen de resistencia Vf2RAD en variedades locales de manzana (Malus domestica)

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    Introduction: DNA sequencing-based methods and nucleotide sequence analysis have become the most common molecular approaches currently used for molecular typing purposes and phylogenetic diversity analysis. Methods: In this study, the nucleotid sequence variations of Powdery mildew resistance gene marker (CH03c02) and the apple scab resistance gene (Vf2RAD) beside phylogenetic diversity of seven apple landraces have been investigated. The two-locus have been successfully cloned and their nucleotide sequences were determined across all studied landraces. Results: Results of sequence alignment of the Powdery mildew resistant locus (CH03c02), compared with that of the published sequence of the same locus of Discovery genotype (HiDRAS),revealed that the nucleotide variations of this locus ranged from 1 to 28 nucleotide substitutions across all seven apple landraces. Whilst, the nucleotide variations of VF2RAD ranged from 2-8 nucleotide substitutions across all the investigated landraces. The highest genetic distance (0.062) was between Amara and Barwari. Whereas, the lowest genetic distance (0.0015) was found between each of the Lubnani, Rechard, Ispartal, and the Ahmadagha. Thenucleotide sequences of the two loci were concatenated and implemented to build a Neighbor-Joining tree. The seven apple landraces were successfully grouped into two main genetic clusters (C1 and C2) in the phylogenetic tree. Conclusions: It can be concluded that the cloning approach used in the current study was found to be very successful and helpful for obtaining the full nucleotide sequences of these two loci. The investigated loci were displayed nucleotide variations among the studied landraces. And, finding of these variations was allowed the distinguishing and discrimination of these landraces

    Extended hypoxia in the alfalfa leafcutting bee, Megachile rotundata, increases survival but causes sub-lethal effects

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    AbstractMany insects are tolerant of hypoxic conditions, but survival may come at a cost to long-term health. The alfalfa leaf-cutting bee, Megachile rotundata, develops in brood cells inside natural cavities, and may be exposed to hypoxic conditions for extended periods of time. Whether M. rotundata is tolerant of hypoxia, and whether exposure results in sub-lethal effects, has never been investigated. Overwintering M. rotundata prepupae were exposed to 10%, 13%, 17%, 21% and 24% O2 for 11months. Once adults emerged, five indicators of quality — emergence weight, body size, feeding activity, flight performance, and adult longevity, — were measured to determine whether adult bees that survived past exposure to hypoxia were competent pollinators. M. rotundata prepupae are tolerant of hypoxic condition and have higher survival rates in hypoxia, than in normoxia. Under hypoxia, adult emergence rates did not decrease over the 11months of the experiment. In contrast, bees reared in normoxia had decreased emergence rates by 8months, and were dead by 11months. M. rotundata prepupae exposed to extended hypoxic conditions had similar emergence weight, head width, and cross-thorax distance compared to bees reared in standard 21% oxygen. Despite no significant morphological differences, hypoxia-exposed bees had lower feeding rates and shorter adult lifespans. Hypoxia may play a role in post-diapause physiology of M. rotundata, with prepupae showing better survival under hypoxic conditions. Extended exposure to hypoxia, while not fatal, causes sub-lethal effects in feeding rates and longevity in the adults, indicating that hypoxia tolerance comes at a cost

    Accounting Hall of Fame induction: Charles Arthur Bowsher; Accounting Hall of Fame induction: Donald James Kirk; Accounting Hall of Fame induction: William Henry Beaver

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    For Charles Arthur Bowsher\u27s induction, the Citation was written by Daniel L. Jensen, Professor , The Ohio State University and read by Arhtur R. Wyatt, professor, University of Illinois and a Rseponse was made by Charles A. Bowsher. For Donald James Kirk\u27s induction, Remarks were made by Paul Kolton, the Citation written by Daniel L. Jensen, Professor, Fisher College of Business, The Ohio State University and read by Paul Kolton, Stamford, Connecticut and a Response made by Donald James Kirk. For the induction of William Henry Beaver, the Remarks were made by Charles T. Horngren, Professor, Stanford University, Hall of Fame Member and the Citation was written by Daniel L. Jensen, Professor, The Ohio State University and read by Charles T. Horngren, Professor, Stanford University, Hall of Fame member and a Response was made by William H. Beaver

    The Factory and The Beehive II. Activity and Rotation in Praesepe and the Hyades

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    Open clusters are collections of stars with a single, well-determined age, and can be used to investigate the connections between angular-momentum evolution and magnetic activity over a star's lifetime. We present the results of a comparative study of the relationship between stellar rotation and activity in two benchmark open clusters: Praesepe and the Hyades. As they have the same age and roughly solar metallicity, these clusters serve as an ideal laboratory for testing the agreement between theoretical and empirical rotation-activity relations at \approx600 Myr. We have compiled a sample of 720 spectra --- more than half of which are new observations --- for 516 high-confidence members of Praesepe; we have also obtained 139 new spectra for 130 high-confidence Hyads. We have collected rotation periods (ProtP_{rot}) for 135 Praesepe members and 87 Hyads. To compare HαH\alpha emission, an indicator of chromospheric activity, as a function of color, mass, and Rossby number RoR_o, we first calculate an expanded set of χ\chi values, with which we can obtain the HαH\alpha to bolometric luminosity ratio, LHα/LbolL_{H\alpha}/L_{bol}, even when spectra are not flux-calibrated and/or stars lack reliable distances. Our χ\chi values cover a broader range of stellar masses and colors (roughly equivalent to spectral types from K0 to M9), and exhibit better agreement between independent calculations, than existing values. We find no difference between the two clusters in their HαH\alpha equivalent width or LHα/LbolL_{H\alpha}/L_{bol} distributions, and therefore take the merged HαH\alpha and ProtP_{rot} data to be representative of 600-Myr-old stars. Our analysis shows that HαH\alpha activity in these stars is saturated for Ro0.110.03+0.02R_o\leq0.11^{+0.02}_{-0.03}. Above that value activity declines as a power-law with slope β=0.730.12+0.16\beta=-0.73^{+0.16}_{-0.12}, before dropping off rapidly at Ro0.4R_o\approx0.4...Comment: 17 pages, 15 figures, Accepted by Ap

    PRIVATE SAVINGS IN TRANSITION ECONOMIES: ARE THERE TERMS OF TRADE SHOCKS?

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    The paper examines the impact of terms of trade shocks on private savings in the transition economies after accounting for the effect of other determinants. Economic agents in the transition economies are subject to tight credit constraints which are more pronounced during bad state of nature. Thus, adverse shocks to commodity prices in the world market can force them to reduce savings by a larger amount than they would otherwise have. Empirical analysis using a dynamic panel model and data from twenty one transition economies confirm that most of the determinants of savings identified in the literature also apply to the transition economies. Favorable movements in both the permanent and transitory components of the terms of trade have a significant positive impact on private savings with transitory movements having a larger impact than the permanent component. This reflects the lack of access to foreign borrowing that many of the transition economies have faced during the last decade. Although the impact of terms of trade shocks are found to be asymmetric, the magnitude of the impact appears to be small. The results are robust for alternative estimators, determinants, and country groupings.http://deepblue.lib.umich.edu/bitstream/2027.42/39958/3/wp572.pd

    Emerging Themes from the ESA Symposium Entitled “Pollinator Nutrition: Lessons from Bees at Individual to Landscape Levels”

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    Pollinator populations are declining (Biesmeijer et al., 2006; Brodschneider et al., 2018; Cameron et al., 2011; Goulson, Lye, & Darvill, 2008; Kulhanek et al., 2017; National Research Council, 2007; Oldroyd, 2007), and both anecdotal and experimental evidence suggest that limited access to high quality forage might play a role (Carvell, Meek, Pywell, Goulson, & Nowakowski, 2007; Deepa et al., 2017; Goulson, Nicholls, Botias, & Rotheray, 2015; Potts et al., 2003, 2010; Vanbergen & The Insect Pollinators Initiative, 2013; Vaudo, Tooker, Grozinger, & Patch, 2015; Woodard, 2017). Multiple researchers are earnestly addressing this topic in a diverse array of insect-pollinator systems. As research continues to be published, increased communication among scientists studying the topic of nutrition is essential for improving pollinator health

    Weighted needle pinprick sensory thresholds: a simple test of sensory function in diabetic peripheral neuropathy

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    A simple device is described, consisting of 12 weighted 23 gauge disposable needles (0.2 to 5.2 g), for testing sensation in busy diabetic clinics. The pinprick sensory threshold (PPT) is the lightest weighted needle which consistently elicits a sharp sensation. The subjects were 48 healthy controls (hospital staff), 44 diabetic patients without neuropathic symptoms, and 35 diabetic patients with chronic painful neuropathy. In the controls, the mean PPT from the right hand and foot obtained on two test occasions a week apart did not differ significantly. In diabetic patients without symptomatic neuropathy, the mean PPT in the right hand and right foot were significantly higher than in the controls. The diabetic patients with painful neuropathy had clearly increased mean PPT in the right hand and foot compared with controls. Marstock thermal limen in diabetic patients with painful neuropathy correlated significantly with PPT determinations. PPT and thermal thresholds probably give comparable information on small fibre dysfunction in diabetic patients with symptomatic neuropathy. Compared with thermal threshold determinations however, the weighted needle apparatus is inexpensive, simple, and rapid to use

    Stochastic Simulation of Biomolecular Networks in Dynamic Environments

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    This is the final version of the article. Available from Public Library of Science via the DOI in this record.Simulation of biomolecular networks is now indispensable for studying biological systems, from small reaction networks to large ensembles of cells. Here we present a novel approach for stochastic simulation of networks embedded in the dynamic environment of the cell and its surroundings. We thus sample trajectories of the stochastic process described by the chemical master equation with time-varying propensities. A comparative analysis shows that existing approaches can either fail dramatically, or else can impose impractical computational burdens due to numerical integration of reaction propensities, especially when cell ensembles are studied. Here we introduce the Extrande method which, given a simulated time course of dynamic network inputs, provides a conditionally exact and several orders-of-magnitude faster simulation solution. The new approach makes it feasible to demonstrate-using decision-making by a large population of quorum sensing bacteria-that robustness to fluctuations from upstream signaling places strong constraints on the design of networks determining cell fate. Our approach has the potential to significantly advance both understanding of molecular systems biology and design of synthetic circuits.MV acknowledges support under an MRC Biomedical Informatics Fellowship. PT acknowledges support by the Royal Commission for the Exhibition of 1851. RG acknowledges support from the Leverhulme Trust (RPG-2013-171). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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