1,131 research outputs found
Assessing the capability of in silico mutation protocols for predicting the finite temperature conformation of amino acids
Mutation protocols are a key tool in computational biophysics for modelling unknown side chain conformations. In particular, these protocols are used to generate the starting structures for molecular dynamics simulations. The accuracy of the initial side chain and backbone placement is crucial to obtain a stable and quickly converging simulation. In this work, we assessed the performance of several mutation protocols in predicting the most probable conformer observed in finite temperature molecular dynamics simulations for a set of protein-peptide crystals differing only by single-point mutations in the peptide sequence. Our results show that several programs which predict well the crystal conformations fail to predict the most probable finite temperature configuration. Methods relying on backbone-dependent rotamer libraries have, in general, a better performance, but even the best protocol fails in predicting approximately 30% of the mutations
Yttrium Geothermometry Applied to Garnets from Different Metamorphic Grades Analysed by EPMA and µ-PIXE Techniques
A model to explain angular distributions of and decays into and
BESIII data show a particular angular distribution for the decay of the
and mesons into the hyperons
and . More in details the angular distribution of
the decay exhibits an opposite trend
with respect to that of the other three channels: , and
. We define a model to explain the
origin of this phenomenon.Comment: 6 pages, 7 figures, to be published in Chinese Physics
Late metamorphic veins with dominant PS-15 polygonal serpentine in the Monte Avic ultramafite
The ultramafic body of Monte Avic (Aosta Valley, Western Alps,
Italy) consists of antigorite serpentinite and Ti-clinohumite metadunite.
They host late metamorphic veins, up to a couple of centimeters thick,
compact, and homogeneous, with a “porcelain” appearance. Vein colors range
from yellowish to light greenish, light yellowish fading to white, or rare
orange. The veins consist of 15-sector PS-15 polygonal serpentine,
with chemical composition Mg2.85 Fe0.08 Si2.05 O7.05
[OH]3.95. Recognition of this unusual phase is supported by diagnostic
satellite reflections in the X-ray powder diffraction pattern (e.g., at
dobs of 2.502, 2.336, 2.151, and 1.966 Å) TEM images (showing
15-sector polygonal fibers, mostly 200 nm in diameter and a few µm in
length, forming a randomly oriented felt) and a µ-Raman wavenumber,
matching previous data. This different evidence affords the successful
distinction of PS-15 and PS-30, alternatively using TEM images, X-ray powder
diffraction, or the low- and high-wavenumber µ-Raman spectra. At Monte
Avic, the vein emplacement was accompanied by significant fluid pressure, as
suggested by deformation and dismembering of the host rock, with PS-15 grown
within isotropic stress microenvironments characterized by fluid-filled
voids. Random growth of the mass-fiber polygonal serpentine was favored by
low-strain conditions. PS-15 veins formed at the end of the long polyphase
Alpine orogenic evolution, with hydrous fluids possibly deriving from
serpentinite dehydration in the depth.</p
A Cylindrical GEM Inner Tracker for the BESIII experiment at IHEP
The Beijing Electron Spectrometer III (BESIII) is a multipurpose detector
that collects data provided by the collision in the Beijing Electron Positron
Collider II (BEPCII), hosted at the Institute of High Energy Physics of
Beijing. Since the beginning of its operation, BESIII has collected the world
largest sample of J/{\psi} and {\psi}(2s). Due to the increase of the
luminosity up to its nominal value of 10^33 cm-2 s-1 and aging effect, the MDC
decreases its efficiency in the first layers up to 35% with respect to the
value in 2014. Since BESIII has to take data up to 2022 with the chance to
continue up to 2027, the Italian collaboration proposed to replace the inner
part of the MDC with three independent layers of Cylindrical triple-GEM (CGEM).
The CGEM-IT project will deploy several new features and innovation with
respect the other current GEM based detector: the {\mu}TPC and analog readout,
with time and charge measurements will allow to reach the 130 {\mu}m spatial
resolution in 1 T magnetic field requested by the BESIII collaboration. In this
proceeding, an update of the status of the project will be presented, with a
particular focus on the results with planar and cylindrical prototypes with
test beams data. These results are beyond the state of the art for GEM
technology in magnetic field
Índice de massa corporal e aptidão física em adolescentes brasileiros
Evaluate the relationship between body mass index and physical fitness in a cross-sectional sample of Brazilian youth.Methods: Participants were 3849 adolescents (2027 girls) aged 10-17 years. Weight and heightwere measured; body mass index was calculated. Physical fitness was evaluated with a multi-stage 20 m shuttle run (cardiovascular endurance), standing long jump (power), and push-ups(upper body strength). Participants were grouped by sex into four age groups: 10-11, 12-13,14 years. Sex-specific ANOVA was used to evaluate differences in each physicalQ2fitness item among weight status categories by age group. Relationships between body massindex and each physical fitness item were evaluated with quadratic regression models by agegroup within each sex.Results: The PF of thin and normal youth was, with few exceptions, significantly better thanthe physical fitness of overweight and obese youth in each age group by sex. On the other hand,physical fitness performances did not consistently differ, on average, between thin and normalweight and between overweight and obese youths. Results of the quadratic regressions indicateda curvilinear (parabolic) relationship between body mass index and each physical fitness itemin most age groups. Better performances were attained by adolescents in the mid-range of thebody mass index distribution, while performances of youth at the low and high ends of the bodymass index distribution were lower.The first author were supported by the Portuguese Foundation for Science and Technology under grants DTP/04045/2013 , POCI-01-0145-FEDER-006969 , and UID/DTP/00617/2013 ; and by NORTE 2020 under the grant NanoSTIMA: Macro-to-Nano Human Sensing: Towards Integrated Multimodal Health Monitoring and Analytics , NORTE-01-0145-FEDER-000016 .info:eu-repo/semantics/publishedVersio
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