185 research outputs found
The impact of crop management regime on oil content and fatty acid composition in hulless and covered spring barley
Received: November 11th, 2021 ; Accepted: January 30th, 2022 ; Published: March 17th, 2022 ; Correspondence: [email protected] are a minor nutritional component of barley (Hordeum vulgare L.) grain and
have not been as widely explored as the major components. The aim of this study was to
investigate the effect of genotype and environment, including conventional farming system with
three crop management regimes, differing in agrochemical input, and organic farming system, on
oil content and fatty acid composition in grain of two covered and four hulless spring barley
genotypes during two growing seasons. Genotype significantly affected oil content and it was on
average 4.26% and ranged in individual barley samples from 2.87 to 5.53%. We found linoleic,
oleic, palmitic, α-linolenic, stearic and capric fatty acids in average proportions of 55.6; 21.3;
18.6; 3.7; 0.6 and 0.4%, respectively. Higher average oil content and proportion of α-linolenic
acid was found in covered barley. Crop management regime did not significantly affect oil
content but had some effect on the proportion of linoleic, α-linolenic, oleic and stearic acid.
Decrease of chemical inputs was in favour of oil content and proportion of α-linolenic, oleic and
stearic acids but did not promote linoleic acid. Waxy hulless barley line with high oil content and
a very high proportion of linoleic acid was identified
Ultrafast dynamics of coherent optical phonons and nonequilibrium electrons in transition metals
The femtosecond optical pump-probe technique was used to study dynamics of
photoexcited electrons and coherent optical phonons in transition metals Zn and
Cd as a function of temperature and excitation level. The optical response in
time domain is well fitted by linear combination of a damped harmonic
oscillation because of excitation of coherent phonon and a
subpicosecond transient response due to electron-phonon thermalization. The
electron-phonon thermalization time monotonically increases with temperature,
consistent with the thermomodulation scenario, where at high temperatures the
system can be well explained by the two-temperature model, while below
50 K the nonthermal electron model needs to be applied. As the
lattice temperature increases, the damping of the coherent phonon
increases, while the amplitudes of both fast electronic response and the
coherent phonon decrease. The temperature dependence of the damping of
the phonon indicates that population decay of the coherent optical
phonon due to anharmonic phonon-phonon coupling dominates the decay process. We
present a model that accounts for the observed temperature dependence of the
amplitude assuming the photoinduced absorption mechanism, where the signal
amplitude is proportional to the photoinduced change in the quasiparticle
density. The result that the amplitude of the phonon follows the
temperature dependence of the amplitude of the fast electronic transient
indicates that under the resonant condition both electronic and phononic
responses are proportional to the change in the dielectric function.Comment: 10 pages, 9 figures, to appear in Physical Review
Diaryltriazenes as antibacterial agents against methicillin resistant Staphylococcus aureus (MRSA) and Mycobacterium smegmatis
Diaryltriazene derivatives were synthesized and evaluated for their antimicrobial properties. Initial experiments showed some of these compounds to have activity against both methicillin-resistant strains of Staphylococus aureus (MRSA) and Mycobacterium smegmatis, with MICs of 0.02 and 0.03 μg/mL respectively. Those compounds with potent anti-staphylococcal and anti-mycobacterial activity were not found to act as growth inhibitors of mammalian cell lines or yeast. Furthermore, we demonstrated that one of the most active anti-MRSA diaryltriazene derivatives was subject to very low frequencies of resistance at <10−9. Whole genome sequencing of resistant isolates identified mutations in the enzyme that lysylates phospholipids. This could result in the modification of phospholipid metabolism and consequently the characteristics of the staphylococcal cell membrane, ultimately modifying the sensitivity of these pathogens to triazene challenge. Our work has therefore extended the potential range of triazenes, which could yield novel antimicrobials with low levels of resistance
Variation in VKORC1 is associated with vascular dementia
BACKGROUND: The genetic variant rs9923231 (VKORC1) is associated with differences in the coagulation of blood and consequentially with sensitivity to the drug warfarin. Variation in VKORC1 has been linked in a gene-based test to dementia/Alzheimer’s disease in the parents of participants, with suggestive evidence for an association for rs9923231 (p = 1.8×10(–7)), which was included in the genome-wide significant KAT8 locus. OBJECTIVE: Our study aimed to investigate whether the relationship between rs9923231 and dementia persists only for certain dementia sub-types, and if those taking warfarin are at greater risk. METHODS: We used logistic regression and data from 238,195 participants from UK Biobank to examine the relationship between VKORC1, risk of dementia, and the interplay with warfarin use. RESULTS: Parental history of dementia, APOE variant, atrial fibrillation, diabetes, hypertension, and hypercholesterolemia all had strong associations with vascular dementia (p < 4.6×10(–6)). The T-allele in rs9923231 was linked to a lower warfarin dose (β(perT - allele) = –0.29, p < 2×10(–16)) and risk of vascular dementia (OR = 1.17, p = 0.010), but not other dementia sub-types. However, the risk of vascular dementia was not affected by warfarin use in carriers of the T-allele. CONCLUSION: Our study reports for the first time an association between rs9923231 and vascular dementia, but further research is warranted to explore potential mechanisms and specify the relationship between rs9923231 and features of vascular dementia
Utility of knife-edge position tracking in cycloidal computed tomography
Cycloidal computed tomography provides high-resolution images within relatively short scan times by combining beam modulation with dedicated under-sampling. However, implementing the technique relies on accurate knowledge of the sample’s motion, particularly in the case of continuous scans, which is often unavailable due to hardware or software limitations. We have developed an easy-to-implement position tracking technique using a sharp edge, which can provide reliable information about the trajectory of the sample and thus improve the reconstruction process. Furthermore, this approach also enables the development of other innovative sampling schemes, which may otherwise be difficult to implement
Two component dark matter
We explain the PAMELA positron excess and the PPB-BETS/ATIC e+ + e- data
using a simple two component dark matter model (2DM). The two particle species
in the dark matter sector are assumed to be in thermal equilibrium in the early
universe. While one particle is stable and is the present day dark matter, the
second one is metastable and decays after the universe is 10^-8 s old. In this
model it is simple to accommodate the large boost factors required to explain
the PAMELA positron excess without the need for large spikes in the local dark
matter density. We provide the constraints on the parameters of the model and
comment on possible signals at future colliders.Comment: 6 pages, 2 figures, discussion clarified and extende
Determining using with multibody D decays
We propose a method for determining using decays
followed by a multibody decay, such as , and . The main advantages of the method is
that it uses only Cabibbo allowed decays, and that large strong phases are
expected due to the presence of resonances. Since no knowledge about the
resonance structure is needed, can be extracted without any hadronic
uncertainty.Comment: 17 pages, 1 figur
Limits on scalar leptoquark interactions and consequences for GUTs
A colored weak singlet scalar state with hypercharge 4/3 is one of the
possible candidates for the explanation of the unexpectedly large
forward-backward asymmetry in t tbar production as measured by the CDF and D0
experiments. We investigate the role of this state in a plethora of flavor
changing neutral current processes and precision observables of down-quarks and
charged leptons. Our analysis includes tree- and loop-level mediated
observables in the K and B systems, the charged lepton sector, as well as the Z
to b bbar decay width. We perform a global fit of the relevant scalar
couplings. This approach can explain the (g-2)_mu anomaly while tensions among
the CP violating observables in the quark sector, most notably the nonstandard
CP phase (and width difference) in the Bs system cannot be fully relaxed. The
results are interpreted in a class of grand unified models which allow for a
light colored scalar with a mass below 1TeV. We find that the renormalizable
SU(5) scenario is not compatible with our global fit, while in the SO(10) case
the viability requires the presence of both the 126- and 120-dimensional
representations.Comment: 26 pages, 7 figures; version as publishe
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