416 research outputs found
Timing of Susceptibility to Fusarium Head Blight in Winter Wheat.
The duration of wheat susceptibility to Fusarium infection has implications for risk forecasting, fungicide timing, and the likelihood that visible kernel damage may underpredict deoxynivalenol (DON) contamination. A field experiment was conducted to explore the impact of varying infection timings on Fusarium head blight (FHB) development in winter wheat. Trials in four successive years (2010 to 2013) in North Carolina utilized one susceptible and one moderately resistant cultivar possessing similar maturity, stature, and grain quality. Inoculum was applied in the form of sprayed Fusarium graminearum conidia. In the first year, the nine infection timings were from 0 to 21 days after anthesis (daa), whereas in the following 3 years, they ranged from 0 to 13 daa. Infection progression was compared among inoculation timings by sampling spikes five to six times during grain-fill. Based on DON, percent kernel damage and kernel infection, and fungal spread as assayed via qPCR, the moderately resistant cultivar had at least a 2- to 3-day shorter window of susceptibility to damaging FHB infection than the susceptible cultivar. The results suggest that duration of susceptibility is an important aspect of cultivar resistance to FHB. In 2012, the window of susceptibility for both cultivars was extended by cold snaps during anthesis. After debranning in one year, the majority of DON was found to be in the bran fraction of kernels; there was also a trend for later infections to lead to a higher percentage of DON in the nonbran fraction, as well as a higher ratio of DON to FDK
Analysis of ergosterol in single kernel and ground grain by gas chromatography-mass spectrometry
A method for analyzing ergosterol in a single kernel and ground barley and wheat was developed using gas chromatography−mass spectrometry (GC-MS). Samples were saponified in methanolic KOH. Ergosterol was extracted by “one step” hexane extraction and subsequently silylated by N-trimethylsilylimidazole/trimethylchlorosilane (TMSI/TMCS) reagent at room temperature. The recoveries of ergosterol from ground barley were 96.6, 97.1, 97.1, 88.5, and 90.3% at the levels of 0.2, 1, 5, 10, and 20 μg/g (ppm), respectively. The recoveries from a single kernel were between 93.0 and 95.9%. The precision (coefficient of variance) of the method was in the range 0.8−12.3%. The method detection limit (MDL) and the method quantification limit (MQL) were 18.5 and 55.6 ng/g (ppb), respectively. The ergosterol analysis method developed can be used to handle 80 samples daily by one person, making it suitable for screening cereal cultivars for resistance to fungal infection. The ability for detecting low levels of ergosterol in a single kernel provides a tool to investigate early fungal invasion and to study mechanisms of resistance to fungal diseases
Nickel-Catalyzed Sonogashira Coupling Reactions of Nonactivated Alkyl Chlorides under Mild Conditions
A study of health effects of long-distance ocean voyages on seamen using a data classification approach
Background: Long-distance ocean voyages may have substantial impacts on seamen’s health, possibly causing malnutrition and other illness. Measures can possibly be taken to prevent such problems from happening through preparing special diet and making special precautions prior or during the sailing if a detailed understanding can be gained about what specific health effects such voyages may have on the seamen.
Methods: We present a computational study on 200 seamen using 41 chemistry indicators measured on their blood samples collected before and after the sailing. Our computational study is done using a data classification approach with a support vector machine-based classifier in conjunction with feature selections using a recursive feature elimination procedure.
Results: Our analysis results suggest that among the 41 blood chemistry measures, nine are most likely to be affected during the sailing, which provide important clues about the specific effects of ocean voyage on seamen’s health.
Conclusions: The identification of the nine blood chemistry measures provides important clues about the effects of long-distance voyage on seamen’s health. These findings will prove to be useful to guide in improving the living and working environment, as well as food preparation on ships
Addressing mood and fatigue in return-to-work programmes after stroke: a systematic review
IntroductionReturn-to-work is a key rehabilitation goal for many working aged stroke survivors, promoting an overall improvement of quality of life, social integration, and emotional wellbeing. Conversely, the failure to return-to-work contributes to a loss of identity, lowered self-esteem, social isolation, poorer quality of life and health outcomes. Return-to-work programmes have largely focused on physical and vocational rehabilitation, while neglecting to include mood and fatigue management. This is despite the knowledge that stroke results in changes in physical, cognitive, and emotional functioning, which all impact one’s ability to return to work. The purpose of this systematic review is to conduct a comprehensive and up-to-date search of randomised controlled trials (RCTs) of return-to-work programmes after stroke. The focus is especially on examining components of mood and fatigue if they were included, and to also report on the screening tools used to measure mood and fatigue.MethodSearches were performed using 7 electronic databases for RCTs published in English from inception to 4 January 2023. A narrative synthesis of intervention design and outcomes was provided.ResultsThe search yielded 5 RCTs that satisfied the selection criteria (n = 626). Three studies included components of mood and fatigue management in the intervention, of which 2 studies found a higher percentage of subjects in the intervention group returning to work compared to those in the control group. The remaining 2 studies which did not include components of mood and fatigue management did not find any significant differences in return-to-work rates between the intervention and control groups. Screening tools to assess mood or fatigue were included in 3 studies.ConclusionOverall, the findings demonstrated that mood and fatigue are poorly addressed in rehabilitation programmes aimed at improving return-to-work after stroke, despite being a significant predictor of return-to-work. There is limited and inconsistent use of mood and fatigue screening tools. The findings were generally able to provide guidance and recommendations in the development of a stroke rehabilitation programme for return-to-work, highlighting the need to include components addressing and measuring psychological support and fatigue management
Optical Sorter-Based Selection Effectively Identifies Soft Red Winter Wheat Breeding Lines with \u3cem\u3eFhb1\u3c/em\u3e and Enhances FHB Resistance in Lines with and without \u3cem\u3eFhb1\u3c/em\u3e
Previous results from our lab have shown that using an optical sorter to identify Fusarium head blight (FHB) resistant breeding lines was effective at reducing the toxin deoxynivalenol (DON) and FHB-associated kernel damage. In this paper we quantified the proportion of desirable genotypes at FHB resistance QTL in lines from three selection cycles of optical sorting. Breeding lines were genotyped at loci on chromosomes 3BS, 2DL, and 5A using the following DNA markers: TaHRC, CFD233, and GWM304. TaHRC is a KASP marker for Fhb1, a major FHB resistance QTL on chromosome 3BS. CFD233 is an SSR marker for Qfhs.nau-2DL on chromosome 2DL. GWM304 is an SSR marker for Qfhs.ifa-5A on chromosome 5A. Sorter selection was effective at identifying lines that had the resistant genotype at TaHRC; in other words, the sorter was able to identify lines with resistance alleles at Fhb1. The sorter was less effective at selecting for the resistant genotype at CFD233 and GWM304. However, the proportion of lines with resistant genotypes at GWM304 did increase with additional sorter selection, just not to the degree that was observed for the Fhb1-associated marker. The proportion of lines with resistant alleles at CFD233 did not show a consistent trend. In addition to increasing the proportion of lines with Fhb1 and Qfhs.ifa-5A each selection cycle, optical sorter-based mass selection enhanced FHB resistance in different marker genotype combinations evaluated in this study. For example, there were net reductions in DON and kernel damage after two cycles of sorter selection in 15X110601S07002, a line with Fhb1, with Qfhs.nau-2DL, and with Qfhs.ifa-5A; final C3 DON levels were 63% of the resistant check (KY02C-3005-25). Kernel damage was also reduced in 15X110601A08221 a line without Fhb1, without Qfhs.nau-2DL, and without Qfhs.ifa-5A. Our findings suggest the increased resistance observed in different marker genotype combinations was conferred by QTL other than Fhb1, QFhs.nau-2DL, and Qfhs.ifa-5, and validate our previous results that the optical sorter is effective at selecting FHB-resistant breeding material
Unreliable quantitation of species abundance based on high-throughput sequencing data of zooplankton communities
High-throughput sequencing (HTS) is rapidly becoming a popular and robust tool to characterize biodiversity of complex communities, especially for those dominated by microscopic species such as zooplankton. The popular use of HTS-based methods has prompted a possible method of inferring relative species abundance from sequencing data. However, these methods remain largely untested in many communities as to whether sequence data can reliably quantify relative species abundance. Here we tested the relationship between species abundance and sequence abundance in zooplankton using 2 methods: (1) spiking known amounts of indicator species into existing zooplankton communities, and (2) comparing results obtained from parallel replicates for the same natural zooplankton communities. Although we detected a general trend that low-abundance species usually corresponded to low-abundance sequence reads, further statistical analyses revealed that sequencing data could not reliably quantify relative species abundance, even for the same indicator species spiked into different zooplankton communities. The distribution of sequence reads statistically varied even between parallel replicates of the same natural zooplankton communities. Our study reveals that sequence abundance may generally qualitatively reflect species abundance as the general trend between these 2 variables exists; however, extra caution is required when using HTS-based approaches to make quantitative inferences regarding zooplankton communities
Solvent-Free Hydrosilylation of Alkenes Catalyzed by Well-Defined Low-Valent Cobalt Catalysts
Identifying Rare FHB-Resistant Segregants in Intransigent Backcross and F\u3csub\u3e2\u3c/sub\u3e Winter Wheat Populations
Fusarium head blight (FHB), caused mainly by Fusarium graminearum Schwabe [telomorph: Gibberella zeae Schwein.(Petch)] in the US, is one of the most destructive diseases of wheat (Triticum aestivum L. and T. durum L.). Infected grain is usually contaminated with deoxynivalenol (DON), a serious mycotoxin. The challenge in FHB resistance breeding is combining resistance with superior agronomic and quality characteristics. Exotic QTL are widely used to improve FHB resistance. Success depends on the genetic background into which the QTL are introgressed, whether through backcrossing or forward crossing; QTL expression is impossible to predict. In this study four high-yielding soft red winter wheat breeding lines with little or no scab resistance were each crossed to a donor parent (VA01W-476) with resistance alleles at two QTL: Fhb1 (chromosome 3BS) and QFhs.nau-2DL (chromosome 2DL) to generate backcross and F2 progeny. F2 individuals were genotyped and assigned to 4 groups according to presence/ absence of resistance alleles at one or both QTL. The effectiveness of these QTL in reducing FHB rating, incidence, index, severity, Fusarium-damaged kernels (FDK) and DON, in F2-derived lines was assessed over 2 years. Fhb1 showed an average reduction in DON of 17.5%, and conferred significant resistance in 3 of 4 populations. QFhs.nau-2DL reduced DON 6.7% on average and conferred significant resistance in 2 of 4 populations. The combination of Fhb1 and QFhs.nau-2DL resistance reduced DON 25.5% across all populations. Double resistant lines had significantly reduced DON compared to double susceptible lines in 3 populations. Backcross derived progeny were planted in replicated yield trials (2011 and 2012) and in a scab nursery in 2012. Several top yielding lines performed well in the scab nursery, with acceptable DON concentrations, even though the average effect of either QTL in this population was not significant. Population selection is often viewed as an “all or nothing” process: if the average resistance level is insufficient, the population is discarded. These results indicate that it may be possible to find rare segregants which combine scab resistance, superior agronomic performance and acceptable quality even in populations in which the average effect of the QTL is muted or negligible
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