562 research outputs found
Identification of Mexican Maize Races (Zea mays L.) with Drought Tolerance using Osmotic Potential Experiments for Genetic Breeding
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)
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
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
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 Πp -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
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
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
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 with the HERA-B Detector
We report on a search for the flavor-changing neutral current decay using 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 .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
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 branching fraction
The branching fraction is measured in a data sample
corresponding to 0.41 of integrated luminosity collected with the LHCb
detector at the LHC. This channel is sensitive to the penguin contributions
affecting the sin2 measurement from The
time-integrated branching fraction is measured to be . This is the most precise measurement to
date
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