562 research outputs found

    Identification of Mexican Maize Races (Zea mays L.) with Drought Tolerance using Osmotic Potential Experiments for Genetic Breeding

    Get PDF
    Received: July 13th, 2023 ; Accepted: September 23rd, 2023 ; Published: October 23rd, 2023 ; Correspondence: [email protected] (Zea mays L.) is the third most important cereal crop worldwide after wheat and rice per cultivated area with 249,225,876 hectares and the most important crop for number of harvested grain tons with 1,482,997,259 in 2021. Some native Mexican maize races could be a source for drought tolerance to improve commercial cultivars and hybrids. The experiments were conducted using various osmotic pressures (OP) induced by polyethylene glycol (PEG-6000) (0, -0.05, -0.15, -0.30 and -0.49 MPa) simulating an increase of drought stress in ten maize genotypes. The main objectives of this study were the evaluation of germination and seedling growth components in response to drought stress and the identification of sources of drought tolerance in Mexican maize races. Apachito-r showed an increased germination in 110.4%, Cristalino-079 had a decreased germination in 98.7% and Cristalino-279 reduced its germination in a 91.1% compared to the control. Apachito-r outstands in root length at -0.05 OP increasing 200.1% and at -0.49 increasing 129.8%. The values for stem length were decreasing as the OP was increasing and only Apachito-r showed a significant difference at -0.30 MPa decreasing 39.8% respect to its control. Cristalino-279 showed significant difference in the variable root fresh weight and its value outstand at -0.15 increasing 267.2%, at -0.30 increasing 281.6% and at -0.49 MPa increasing 189.3% compared to the control in water. The variable root dry weight had the highest value for Apachito-r at -0.05 MPa increasing in a 189.4%, decreasing at -0.15 in 72% and at -0.30 MPa in a 79.8% and increasing at -0.49 MPa in 112.3%. Also noteworthy are E-zapata-r increasing 190.5% and Cristalino-061 increasing 142.9% at -0.30. E-zapata-r at -0.49 increased 115.1%. Cristalino-279 showed significant difference in the variable stem fresh weight and its value outstand at -0.05, -0.15 and -0.30 MPa increasing 146.7%, 103.7% and 60.2% respectively. Finally, in stem dry weight the tendency was to decrease as OP was increasing, however Cristalino-279 showed differences at -0.30 decreasing in 89.5% and at -0.49 MPa increasing in a 143.5% respect to the control. The most drought tolerant genotypes were Cristalino-279, Apachito-r, Azul and 8-carreras-PP. The most tolerant genotypes showed greater root length, greater root fresh and dry weight, better germination and greater stem length. Resistant and susceptible genotypes are ideal material to understand the physical and chemical mechanisms related to drought tolerance. Cristalino-279 shows the best level of drought tolerance at all levels of osmotic pressure, this genotype can be used as a source of drought tolerance for the improvement of commercial maize

    Heat Conduction and Magnetic Phase Behavior in Electron-Doped Ca_{1-x} La_x MnO_3(0 <= x <= 0.2)

    Full text link
    Measurements of thermal conductivity (kappa) vs temperature are reported for a series of Ca_{1-x} La_x MnO_3(0 <= x <= 0.2) specimens. For the undoped (x=0), G-type antiferromagnetic compound a large enhancement of kappa below the Neel temperature (T_N ~ 125 K) indicates a strong coupling of heat-carrying phonons to the spin system. This enhancement exhibits a nonmonotonic behavior with increasing x and correlates remarkably well with the small ferromagnetic component of the magnetization reported previously [Neumeier and Cohn, Phys. Rev. B 61 14319 (2000).] Magnetoelastic polaron formation appears to underly the behavior of kappa and the magnetization at x <= 0.02.Comment: submitted to PRB; 4 pp., 4 Fig.'s, RevTex

    Application of bioelectrical impedance analysis in prediction of light kid carcass and muscle chemical composition

    Get PDF
    Carcass data were collected from 24 kids (average live weight of 12.5±5.5 kg; range 4.5 to 22.4 kg) of Jarmelista Portuguese native breed, to evaluate bioelectrical impedance analysis (BIA) as a technique for prediction of light kid carcass and muscle chemical composition. Resistance (Rs, Ω) and reactance (Xc, Ω), were measured in the cold carcasses with a single frequency bioelectrical impedance analyzer and, together with impedance (Z, Ω), two electrical volume measurements (VolA and VolB, cm2/Ω), carcass cold weight (CCW), carcass compactness and several carcass linear measurements were fitted as independent variables to predict carcass composition by stepwise regression analysis. The amount of variation explained by VolA and VolB only reached a significant level (P<0.01 and P<0.05, respectively) for muscle weight, moisture, protein and fat-free soft tissue content, even so with low accuracy, with VolA providing the best results (0.326⩜R 2⩜0.366). Quite differently, individual BIA parameters (Rs, Xc and Z) explained a very large amount of variation in dissectible carcass fat weight (0.814⩜R 2⩜0.862; P<0.01). These individual BIA parameters also explained a large amount of variation in subcutaneous and intermuscular fat weights (respectively 0.749⩜R 2⩜0.793 and 0.718⩜R 2⩜0.760; P<0.01), and in muscle chemical fat weight (0.663⩜R 2⩜0.684; P<0.01). Still significant but much lower was the variation in muscle, moisture, protein and fat-free soft tissue weights (0.344⩜R 2⩜0.393; P<0.01) explained by BIA parameters. Still, the best models for estimation of muscle, moisture, protein and fat-free soft tissue weights included Rs in addition to CCW, and accounted for 97.1% to 99.8% (P<0.01) of the variation observed, with CCW by itself accounting for 97.0% to 99.6% (P<0.01) of that variation. Resistance was the only independent variable selected for the best model predicting subcutaneous fat weight. It was also selected for the best models predicting carcass fat weight (combined with carcass length, CL; R 2=0.943; P<0.01) and intermuscular fat weight (combined with CCW; R 2=0.945; P<0.01). The best model predicting muscle chemical fat weight combined CCW and Z, explaining 85.6% (P<0.01) of the variation observed. These results indicate BIA as a useful tool for prediction of light kids' carcass composition.This work was supported by the Portuguese Science and Technology Foundation (FCT) under the Project PEst-OE/AGR/UID/CVT/00772/2013.info:eu-repo/semantics/publishedVersio

    PSA based multi objective evolutionary algorithms

    Get PDF
    It has generally been acknowledged that both proximity to the Pareto front and a certain diversity along the front, should be targeted when using evolutionary multiobjective optimization. Recently, a new partitioning mechanism, the Part and Select Algorithm (PSA), has been introduced. It was shown that this partitioning allows for the selection of a well-diversified set out of an arbitrary given set, while maintaining low computational cost. When embedded into an evolutionary search (NSGA-II), the PSA has significantly enhanced the exploitation of diversity. In this paper, the ability of the PSA to enhance evolutionary multiobjective algorithms (EMOAs) is further investigated. Two research directions are explored here. The first one deals with the integration of the PSA within an EMOA with a novel strategy. Contrary to most EMOAs, that give a higher priority to proximity over diversity, this new strategy promotes the balance between the two. The suggested algorithm allows some dominated solutions to survive, if they contribute to diversity. It is shown that such an approach substantially reduces the risk of the algorithm to fail in finding the Pareto front. The second research direction explores the use of the PSA as an archiving selection mechanism, to improve the averaged Hausdorff distance obtained by existing EMOAs. It is shown that the integration of the PSA into NSGA-II-I and Δ p -EMOA as an archiving mechanism leads to algorithms that are superior to base EMOAS on problems with disconnected Pareto fronts. © 2014 Springer International Publishing Switzerland

    Non-Invasive Monitoring of Inflammation in Inflammatory Bowel Disease Patients during Prolonged Exercise via Exhaled Breath Volatile Organic Compounds

    Get PDF
    The aim of this study was to investigate volatile organic compounds (VOCs) in exhaled breath as possible non-invasive markers to monitor the inflammatory response in inflammatory bowel disease (IBD) patients as a result of repeated and prolonged moderate-intensity exercise. We included 18 IBD patients and 19 non-IBD individuals who each completed a 30, 40, or 50 km walking exercise over three consecutive days. Breath and blood samples were taken before the start of the exercise event and every day post-exercise to assess changes in the VOC profiles and cytokine concentrations. Proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) was used to measure exhaled breath VOCs. Multivariate analysis, particularly ANOVA-simultaneous component analysis (ASCA), was employed to extract relevant ions related to exercise and IBD. Prolonged exercise induces a similar response in breath butanoic acid and plasma cytokines for participants with or without IBD. Butanoic acid showed a significant correlation with the cytokine IL-6, indicating that butanoic acid could be a potential non-invasive marker for exercise-induced inflammation. The findings are relevant in monitoring personalized IBD management

    Colossal dielectric constants in transition-metal oxides

    Get PDF
    Many transition-metal oxides show very large ("colossal") magnitudes of the dielectric constant and thus have immense potential for applications in modern microelectronics and for the development of new capacitance-based energy-storage devices. In the present work, we thoroughly discuss the mechanisms that can lead to colossal values of the dielectric constant, especially emphasising effects generated by external and internal interfaces, including electronic phase separation. In addition, we provide a detailed overview and discussion of the dielectric properties of CaCu3Ti4O12 and related systems, which is today's most investigated material with colossal dielectric constant. Also a variety of further transition-metal oxides with large dielectric constants are treated in detail, among them the system La2-xSrxNiO4 where electronic phase separation may play a role in the generation of a colossal dielectric constant.Comment: 31 pages, 18 figures, submitted to Eur. Phys. J. for publication in the Special Topics volume "Cooperative Phenomena in Solids: Metal-Insulator Transitions and Ordering of Microscopic Degrees of Freedom

    Exhaled breath reflects prolonged exercise and statin use during a field campaign

    Get PDF
    Volatile organic compounds (VOCs) in exhaled breath provide insights into various metabolic processes and can be used to monitor physiological response to exercise and medication. We integrated and validated in situ a sampling and analysis protocol using proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) for exhaled breath research. The approach was demonstrated on a participant cohort comprising users of the cholesterol-lowering drug statins and non-statin users during a field campaign of three days of prolonged and repeated exercise, with no restrictions on food or drink consumption. The effect of prolonged exercise was reflected in the exhaled breath of participants, and relevant VOCs were identified. Most of the VOCs, such as acetone, showed an increase in concentration after the first day of walking and subsequent decrease towards baseline levels prior to walking on the second day. A cluster of short-chain fatty acids including acetic acid, butanoic acid, and propionic acid were identified in exhaled breath as potential indicators of gut microbiota activity relating to exercise and drug use. We have provided novel information regarding the use of breathomics for non-invasive monitoring of changes in human metabolism and especially for the gut microbiome activity in relation to exercise and the use of medication, such as statin

    Search for the Flavor-Changing Neutral Current Decay D0→Ό+Ό−D^0 \to \mu^+\mu^- with the HERA-B Detector

    Get PDF
    We report on a search for the flavor-changing neutral current decay D0→Ό+Ό−D^0 \to \mu^+\mu^- using 50×10650 \times 10^6 events recorded with a dimuon trigger in interactions of 920 GeV protons with nuclei by the HERA-B experiment. We find no evidence for such decays and set a 90% confidence level upper limit on the branching fraction Br(D0→Ό+Ό−)<2.0×10−6Br(D^0 \to \mu^+\mu^-) <2.0 \times 10^{-6}.Comment: 17 pages, 4 figures (of which 1 double), paper to be submitted to Physics Letters

    Measurement of the J/Psi Production Cross Section in 920 GeV/c Fixed-Target Proton-Nucleus Interactions

    Get PDF
    The mid-rapidity (dsigma_(pN)/dy at y=0) and total sigma_(pN) production cross sections of J/Psi mesons are measured in proton-nucleus interactions. Data collected by the HERA-B experiment in interactions of 920 GeV/c protons with carbon, titanium and tungsten targets are used for this analysis. The J/Psi mesons are reconstructed by their decay into lepton pairs. The total production cross section obtained is sigma_(pN)(J/Psi) = 663 +- 74 +- 46 nb/nucleon. In addition, our result is compared with previous measurements

    Measurement of the Bs0→J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction

    Get PDF
    The Bs0→J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction is measured in a data sample corresponding to 0.41fb−1fb^{-1} of integrated luminosity collected with the LHCb detector at the LHC. This channel is sensitive to the penguin contributions affecting the sin2ÎČ\beta measurement from B0→J/ψKS0B^0\to J/\psi K_S^0 The time-integrated branching fraction is measured to be BF(Bs0→J/ψKS0)=(1.83±0.28)×10−5BF(B_s^0\to J/\psi K_S^0)=(1.83\pm0.28)\times10^{-5}. This is the most precise measurement to date
    • 

    corecore