667 research outputs found
Myers' type theorems and some related oscillation results
In this paper we study the behavior of solutions of a second order
differential equation. The existence of a zero and its localization allow us to
get some compactness results. In particular we obtain a Myers' type theorem
even in the presence of an amount of negative curvature. The technique we use
also applies to the study of spectral properties of Schroedinger operators on
complete manifolds.Comment: 16 page
The Genetics of Atypical Femur Fractures—a Systematic Review
Purpose of Review: Atypical femur fractures (AFFs) are rare subtrochanteric or diaphyseal fractures regarded as side effects of bisphosphonates (BPs), possibly with a genetic background. Here, we summarize the most recent knowledge about genetics of AFFs. Recent Findings: AFF has been reported in 57 patients with seven different monogenic bone disorders including hypophosphatasia and osteogenesis imperfecta; 56.1% had never used BPs, while 17.5% were diagnosed with the disorder only after the AFF. Gene mutation finding in familial and sporadic cases identified possible AFF-related variants in the GGPS1 and ATRAID genes respectively. Functional follow-up studies of mutant proteins showed possible roles in AFF. A recent small genome-wide association study on 51 AFF cases did not identify significant hits associated with AFF. Summary: Recent findings have strengthened the hypothesis that AFFs have underlying genetic components but more studies are needed in AFF families and larger cohorts of sporadic cases to confirm previous results and/or find novel gene variants involved in the pathogenesis of AFFs
The open-charm radiative and pionic decays of molecular charmonium Y(4274)
In this work, we investigate the decay widths and the line shapes of the
open-charm radiative and pionic decays of Y(4274) with the
molecular charmonium assignment. Our calculation
indicates that the decay widths of and
can reach up to 0.05 keV and 0.75 keV,
respectively. In addition, the result of the line shape of the photon spectrum
of shows that there exists a very sharp
peak near the large end point of photon energy. The line shape of the pion
spectrum of is similar to that of the pion
spectrum of , where we also find a very
sharp peak near the large end point of pion energy. According to our
calculation, we suggest further experiments to carry out the search for the
open-charm radiative and pionic decays of Y(4274).Comment: 7 pages, 6 figures, 1 table. Published versio
Orientational order in dipolar fluids consisting of nonspherical hard particles
We investigate fluids of dipolar hard particles by a certain variant of
density-functional theory. The proper treatment of the long range of the
dipolar interactions yields a contribution to the free energy which favors
ferromagnetic order. This corrects previous theoretical analyses. We determine
phase diagrams for dipolar ellipsoids and spherocylinders as a function of the
aspect ratio of the particles and their dipole moment. In the nonpolar limit
the results for the phase boundary between the isotropic and nematic phase
agree well with simulation data. Adding a longitudinal dipole moment favors the
nematic phase. For oblate or slightly elongated particles we find a
ferromagnetic liquid phase, which has also been detected in computer
simulations of fluids consisting of spherical dipolar particles. The detailed
structure of the phase diagram and its evolution upon changing the aspect ratio
are discussed in detail.Comment: 35 pages LaTeX with epsf style, 11 figures in eps format, submitted
to Phys. Rev.
Frame-shift mutation causes the function loss of TaMYB-A1 regulating anthocyanin biosynthesis in Triticum aestivum
Red coleoptile is an easily observed trait in Triticum aestivum and can provide some protection against stress. Here, TaMYB-A1 or TuMYB-A1, homologous to TaMYB-D1, which controls red coleoptile formation in the common wheat cultivar ‘Gy115’, was isolated from eight T. aestivum and 34 T. urartu cultivars. The genome sequence of TaMYB-A1 was 867 bp with an intron of 93 bp, which was similar to the MYBs regulating anthocyanin biosynthesis in T. aestivum but different from other MYB transcription factors regulating anthocyanin biosynthesis. TaMYB-A1 had an integrated DNA-binding domain of 102 amino acids and a transcriptional domain of 42 amino acids, which was responsible for regulating anthocyanin biosynthesis. TaMYB-A1 was assigned to the same branch as the MYBs regulating anthocyanin biosynthesis in a phylogenetic tree. A transient expression analysis showed that TaMYB-A1 induced ‘Opata’ coleoptile cells to synthesize anthocyanin with the help of ZmR. A non-functional allele of TaMYB-a1 existed in common wheat cultivars containing rc-a1. One single nucleotide was deleted 715 bp after the start codon in TaMYB-a1 compared with TaMYB-A1. The deletion caused a frame shift mutation, destroyed the DNA transcription activator domain, and resulted in TaMYB-a1 losing its ability to regulate anthocyanin biosynthesis in ‘Opata’ coleoptile cells. Those cultivars with functional TaMYB-A1 or TuMYB-A1 have red coleoptiles. The isolation of TaMYB-A1 should aid in understanding the molecular mechanisms of coleoptile traits in T. aestivum
Energy band structure and intrinsic coherent properties in two weakly linked Bose Einstein Condensates
The energy band structure and energy splitting due to quantum tunneling in
two weakly linked Bose-Einstein condensates were calculated by using the
instanton method. The intrinsic coherent properties of Bose Josephson junction
were investigated in terms of energy splitting. For , the
energy splitting is small and the system is globally phase coherent. In the
opposite limit, , the energy splitting is large and the
system becomes a phase dissipation. Our reslults suggest that one should
investigate the coherence phenomna of BJJ in proper condition such as
.Comment: to appear in Phys. Rev. A, 2 figure
Prevalence of Monogenic Bone Disorders in a Dutch Cohort of Atypical Femur Fracture Patients
Atypical femur fractures (AFFs), considered rare associations of bisphosphonates, have also been reported in patients with monogenic bone disorders without bisphosphonate use. The exact association between AFFs and monogenic bone disorders remains unknown. Our aim was to determine the prevalence of monogenic bone disorders in a Dutch AFF cohort. AFF patients were recruited from two specialist bone centers in the Netherlands. Medical records of the AFF patients were reviewed for clinical features of monogenic bone disorders. Genetic variants identified by whole-exome sequencing in 37 candidate genes involved in monogenic bone disorders were classified based on the American College of Medical Genetics and Genomics (ACMG) classification guidelines. Copy number variations overlapping the candidate genes were also evaluated using DNA array genotyping data. The cohort comprises 60 AFF patients (including a pair of siblings), with 95% having received bisphosphonates. Fifteen AFF patients (25%) had clinical features of monogenic bone disorders. Eight of them (54%), including the pair of siblings, had a (likely) pathogenic variant in either PLS3, COL1A2, LRP5, or ALPL. One patient carried a likely pathogenic variant in TCIRG1 among patients not suspected of monogenic bone disorders (2%). In total, nine patients in this AFF cohort (15%) had a (likely) pathogenic variant. In one patient, we identified a 12.7Â Mb deletion in chromosome 6, encompassing TENT5A. The findings indicate a strong relationship between AFFs and monogenic bone disorders, particularly osteogenesis imperfecta and hypophosphatasia, but mainly in individuals with symptoms of these disorders. The high yield of (likely) pathogenic variants in AFF patients with a clinical suspicion of these disorders stresses the importance of careful clinical evaluation of AFF patients. Although the relevance of bisphosphonate use in this relationship is currently unclear, clinicians should consider these findings in medical management of these patients.</p
Effects of decoherence and errors on Bell-inequality violation
We study optimal conditions for violation of the Clauser-Horne-Shimony-Holt
form of the Bell inequality in the presence of decoherence and measurement
errors. We obtain all detector configurations providing the maximal Bell
inequality violation for a general (pure or mixed) state. We consider local
decoherence which includes energy relaxation at the zero temperature and
arbitrary dephasing. Conditions for the maximal Bell-inequality violation in
the presence of decoherence are analyzed both analytically and numerically for
the general case and for a number of important special cases. Combined effects
of measurement errors and decoherence are also discussed.Comment: 18 pages, 5 figure
The newly observed open-charm states in quark model
Comparing the measured properties of the newly observed open-charm states
D(2550), D(2600), D(2750), D(2760), D_{s1}(2710), D_{sJ}(2860), and
D_{sJ}(3040) with our predicted spectroscopy and strong decays in a constituent
quark model, we find that: (1) the D(2\,^1S_0) assignment to D(2550) remains
open for its too broad width determined by experiment; (2) the D(2600) and
can be identified as the 2\,^3S_1-1\,^3D_1 mixtures; (3) if
the D(2760) and D(2750) are indeed the same resonance, they would be the
D(1\,^3D_3); otherwise, they could be assigned as the D(1\,^3D_3) and
, respectively; (4) the could be either the
's partner or the D_s(1\,^3D_3); and (5) both the
and interpretations for the seem likely. The
and radiative decays of these sates are also studied. Further
experimental efforts are needed to test the present quarkonium assignments for
these new open-charm states.Comment: 26 pages,7 figures, journal versio
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