300 research outputs found
TFH Mixing Patterns, Large and Flavor Symmetry
We perform a comprehensive analysis of the Toorop-Feruglio-Hagedorn (TFH)
mixing patterns within the family symmetry . The general neutrino
mass matrix for the TFH mixing and its symmetry properties are investigated.
The possible realizations of the TFH mixing in are analyzed in the
minimalist approach. We propose two dynamical models which produce the TFH
mixing patterns at leading order. The full flavor symmetries are
and
respectively. The next to leading order terms introduce corrections of order
to the three mixing angles in both models. The allowed mixing
patterns are studied under the condition that the Klein four subgroups and the
cyclic subgroups with are preserved in the neutrino and the
charged lepton sector respectively. We suggest that the deformed tri-bimaximal
mixing is a good leading order approximation to understanding a largish reactor
angle.Comment: 43 pages, 2 figure
Tri-Bimaximal Neutrino Mixing and Discrete Flavour Symmetries
We review the application of non-Abelian discrete groups to Tri-Bimaximal
(TB) neutrino mixing, which is supported by experiment as a possible good first
approximation to the data. After summarizing the motivation and the formalism,
we discuss specific models, mainly those based on A4 but also on other finite
groups, and their phenomenological implications, including the extension to
quarks. The recent measurements of \theta_13 favour versions of these models
where a suitable mechanism leads to corrections to \theta_13 that can naturally
be larger than those to \theta_12 and \theta_23. The virtues and the problems
of TB mixing models are discussed, also in connection with lepton flavour
violating processes, and the different approaches are compared.Comment: 26 pages, 5 figures, 4 tables. V3 submitted to add an acknowledgment
to a network. Review written for the special issue on "Flavor Symmetries and
Neutrino Oscillations", published in Fortschritte der Physik - Progress of
Physic
Analysis of chromatin organization and gene expression in T cells identifies functional genes for rheumatoid arthritis
From Springer Nature via Jisc Publications RouterHistory: received 2019-10-22, accepted 2020-08-06, registration 2020-08-11, pub-electronic 2020-09-02, online 2020-09-02, collection 2020-12Publication status: PublishedFunder: RCUK | MRC | Medical Research Foundation; doi: https://doi.org/10.13039/501100009187; Grant(s): MR/N00017X/1Funder: Arthritis Research UK; doi: https://doi.org/10.13039/501100000341; Grant(s): 21754Abstract: Genome-wide association studies have identified genetic variation contributing to complex disease risk. However, assigning causal genes and mechanisms has been more challenging because disease-associated variants are often found in distal regulatory regions with cell-type specific behaviours. Here, we collect ATAC-seq, Hi-C, Capture Hi-C and nuclear RNA-seq data in stimulated CD4+ T cells over 24 h, to identify functional enhancers regulating gene expression. We characterise changes in DNA interaction and activity dynamics that correlate with changes in gene expression, and find that the strongest correlations are observed within 200 kb of promoters. Using rheumatoid arthritis as an example of T cell mediated disease, we demonstrate interactions of expression quantitative trait loci with target genes, and confirm assigned genes or show complex interactions for 20% of disease associated loci, including FOXO1, which we confirm using CRISPR/Cas9
SU(3) Gauge Family Symmetry and Prediction for the Lepton-Flavor Mixing and Neutrino Masses with Maximal Spontaneous CP Violation
A model for the lepton-flavor mixing and CP violation is proposed based on
the SU(3) gauge family symmetry and the Majorana feature of neutrinos. A
consistent prediction for the lepton-flavor mixing and masses is shown to be
resulted from the appropriate vacuum structure of SU(3) gauge symmetry
breaking. By choosing the SU(3) gauge fixing condition to possess a
residual symmetry and requiring the vacuum structure of spontaneous
symmetry breaking to have approximate global U(1) family symmetries, we obtain
naturally the tri-bimaximal mixing matrix and largely degenerate neutrino
masses in the neutrino sector and the small mixing matrix in the charged-lepton
sector. With a simple ansatz that all the smallness due to the approximate
global U(1) family symmetries is characterized by a single Wolfenstein
parameter , and the charged-lepton mixing matrix has a
similar hierarchy structure as the CKM quark mixing matrix, we arrive at a
consistent prediction for the MNSP lepton-flavor mixing with a maximal
spontaneous CP violation: , (),
and
, which agree well
with the current experimental data. The CP-violating Jarlskog-invariant is
obtained to be , which is detectable in next generation neutrino experiment. The
largely degenerate neutrino masses with the normal hierarchy and inverse
hierarchy are discussed and found be at the order eV with a total mass eV, which is testable in future precision astrophysics and cosmology.Comment: 14 pages, it is explicitly shown that the smallness for both the
charged-lepton mixing and neutrino masses with the standard seesaw mechanism
can naturally be explained by the approximate global U(1) family symmetries
of vacuum structure in the SU(3) gauge family model, references added,
published version in PL
Deviation from Tri-Bimaximal Mixing and Large Reactor Mixing Angle
Recent observations for a non-zero have come from various
experiments. We study a model of lepton mixing with a 2-3 flavor symmetry to
accommodate the sizable measurement. In this work, we derive
deviations from the tri-bimaximal (TBM) pattern arising from breaking the
flavor symmetry in the neutrino sector, while the charged leptons contribution
has been discussed in a previous work. Contributions from both sectors towards
accommodating the non-zero measurement are presented.Comment: 25 pages, 12 figures. arXiv admin note: text overlap with
arXiv:1109.232
Distorted magnetic orders and electronic structures of tetragonal FeSe from first-principles
We use the state-of-the-arts density-functional-theory method to study
various magnetic orders and their effects on the electronic structures of the
FeSe. Our calculated results show that, for the spins of the single Fe layer,
the striped antiferromagnetic orders with distortion are more favorable in
total energy than the checkerboard antiferromagnetic orders with tetragonal
symmetry, which is consistent with known experimental data, and the inter-layer
magnetic interaction is very weak. We investigate the electronic structures and
magnetic property of the distorted phases. We also present our calculated spin
coupling constants and discuss the reduction of the Fe magnetic moment by
quantum many-body effects. These results are useful to understand the
structural, magnetic, and electronic properties of FeSe, and may have some
helpful implications to other FeAs-based materials
Motor, linguistic, personal and social aspects of children with Down syndrome
AbstractA global developmental delay is expected from Down syndrome, affecting motor, cognitive, linguistic and personal-social skills. However, not always these delays are proportional; different conditions occur due to several intrinsic and extrinsic variables that must be controlled to form groups of greater homogeneity.Objective To enhance personal-social, fine motor-adaptive, gross motor and linguistic skills among children with Down syndrome and compare them with typically developing children, matched for gender, socioeconomic status and mental age, while controlling some variables that interfere with the global development.Methods The ethical aspects were fulfilled (Case No. 040/2009). The following inclusion criteria were considered: participants without a history of prematurity, very low birth weight, congenital hypothyroidism, significant hearing and vision problems, and signs of Autism Spectrum Disorder. After the inclusion criteria were considered, 40 children participated in the study, of which 20 had Down syndrome (experimental group - EG), these being of both genders and with chronological ages ranging from 38 to 63 months, and the other 20 being typically developing children (control group - CG), matching the EG in terms of gender, socioeconomic status and mental age, with this age ranging from 13 to 50 months. The evaluation consisted in applying the Denver Developmental Screening Test II, a test that assesses areas such as personal-social, fine motor-adaptive, linguistic and gross motor development. The results were subjected to statistical analysis using Student’s t-test.Results A statistically significant difference was verified between the groups for the language and fine motor-adaptive areas.Conclusion Children with Down syndrome showed lower performance in language and fine motor skills when compared with typically developing children. There was no statistically significant difference in gross motor and personal-social areas. It is worth mentioning the importance of controlling the variables to deal with more homogeneous groups
TRY plant trait database - enhanced coverage and open access
Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
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