284 research outputs found
Local modularity measure for network clusterizations
Many complex networks have an underlying modular structure, i.e., structural
subunits (communities or clusters) characterized by highly interconnected
nodes. The modularity has been introduced as a measure to assess the
quality of clusterizations. has a global view, while in many real-world
networks clusters are linked mainly \emph{locally} among each other
(\emph{local cluster-connectivity}). Here, we introduce a new measure,
localized modularity , which reflects local cluster structure. Optimization
of and on the clusterization of two biological networks shows that the
localized modularity identifies more cohesive clusters, yielding a
complementary view of higher granularity.Comment: 5 pages, 4 figures, RevTex4; Changed conten
Universal response of the type-II Weyl semimetals phase diagram
The discovery of Weyl semimetals represents a significant advance in
topological band theory. They paradigmatically enlarged the classification of
topological materials to gapless systems while simultaneously providing
experimental evidence for the long-sought Weyl fermions. Beyond fundamental
relevance, their high mobility, strong magnetoresistance, and the possible
existence of even more exotic effects, such as the chiral anomaly, make Weyl
semimetals a promising platform to develop radically new technology. Fully
exploiting their potential requires going beyond the mere identification of
materials and calls for a detailed characterization of their functional
response, which is severely complicated by the coexistence of surface- and
bulk-derived topologically protected quasiparticles, i.e., Fermi arcs and Weyl
points, respectively. Here, we focus on the type-II Weyl semimetal class where
we find a stoichiometry-dependent phase transition from a trivial to a
non-trivial regime. By exploring the two extreme cases of the phase diagram, we
demonstrate the existence of a universal response of both surface and bulk
states to perturbations. We show that quasi-particle interference patterns
originate from scattering events among surface arcs. Analysis reveals that
topologically non-trivial contributions are strongly suppressed by spin
texture. We also show that scattering at localized impurities generate
defect-induced quasiparticles sitting close to the Weyl point energy. These
give rise to strong peaks in the local density of states, which lift the Weyl
node significantly altering the pristine low-energy Weyl spectrum. Visualizing
the microscopic response to scattering has important consequences for
understanding the unusual transport properties of this class of materials.
Overall, our observations provide a unifying picture of the Weyl phase diagram
The slow release of BMP-7 at a low dose accelerates dental implant healing in an osteopenic environment.
The aim of the present study was to investigate in vivo whether bone morphogenetic protein-7 (BMP-7) was able to promote and accelerate dental implant healing at a low dose in an osteopenic environment by using a delayed drug-release system. Skeletally mature Chinese goats, having physiologically osteopenic (osteoporotic-like) facial bones, served as an animal model. Dental implants were provided with a delayed-release drug-delivery system and BMP-7 was applied at three different dosages. The implants, inserted into healed extraction sockets, were removed 1, 2 and 3 weeks after surgery. Quantification of osseointegration and formation of new bone in the peri- implant space were measured histomorphometrically. Data revealed no evidence of any adverse drug effect at or near the implantation sites. After the first postoperative week, bone neoformation was minimal; after the second week, peri-implant bone formation appeared, particularly in the groups with low dosages of BMP-7. After 3 weeks, new-bone volume was the largest in the group with the lowest (near-physiological) dosage of BMP-7, also showing the highest efficacy of BMP-7. Other dosage or release modes were found to be significantly less effective. BMP-7 was highly efficacious in promoting and accelerating bone formation in the peri-implant space in a hostile osteopenic environment if released by a slow-mode mechanism over time at near physiological activities. Therefore, biological functionalisation of dental implants by a high-power osteogenic factor may improve their healing success in hostile bony environments (osteopenia, osteoporosis, bone atrophy etc.)
Direct observation of the spin texture in strongly correlated SmB6 as evidence of the topological Kondo insulator
The concept of a topological Kondo insulator (TKI) has been brought forward
as a new class of topological insulators in which non-trivial surface states
reside in the bulk Kondo band gap at low temperature due to the strong
spin-orbit coupling [1-3]. In contrast to other three-dimensional (3D)
topological insulators (e.g. Bi2Se3), a TKI is truly insulating in the bulk
[4]. Furthermore, strong electron correlations are present in the system, which
may interact with the novel topological phase. Applying spin- and
angle-resolved photoemission spectroscopy (SARPES) to the Kondo insulator SmB6,
a promising TKI candidate, we reveal that the surface states of SmB6 are spin
polarized, and the spin is locked to the crystal momentum. Counter-propagating
states (i.e. at k and -k) have opposite spin polarizations protected by
time-reversal symmetry. Together with the odd number of Fermi surfaces of
surface states between the 4 time-reversal invariant momenta in the surface
Brillouin zone [5], these findings prove, for the first time, that SmB6 can
host non-trivial topological surface states in a full insulating gap in the
bulk stemming from the Kondo effect. Hence our experimental results establish
that SmB6 is the first realization of a 3D TKI. It can also serve as an ideal
platform for the systematic study of the interplay between novel topological
quantum states with emergent effects and competing order induced by strongly
correlated electrons.Comment: 4 figure
Antimicrobial susceptibility in E. coli and Pasteurellaceae at the beginning and at the end of the fattening process in veal calves: Comparing 'outdoor veal calf' and conventional operations.
Animal husbandry requires practical measures to limit antimicrobial resistance (AMR). Therefore, a novel management and housing concept for veal calf fattening was implemented on 19 intervention farms (IF) and evaluated regarding its effects on AMR in Escherichia (E.) coli, Pasteurella (P.) multocida and Mannheimia (M.) haemolytica in comparison with 19 conventional control farms (CF). Treatment intensity (-80%) and mortality (-50%) were significantly lower in IF than in CF, however, production parameters did not differ significantly between groups. Rectal and nasopharyngeal swabs were taken at the beginning and the end of the fattening period. Susceptibility testing by determination of the minimum inhibitory concentration was performed on 5420 isolates. The presence of AMR was described as prevalence of resistant isolates (%), by calculating the Antimicrobial Resistance Index (ARI: number of resistance of one isolate to single drugs/total number of drugs tested), by the occurrence of pansusceptible isolates (susceptible to all tested drugs, ARI=0), and by calculating the prevalence of multidrug (≥3) resistant isolates (MDR). Before slaughter, odds for carrying pansusceptible E. coli were higher in IF than in CF (+65%, p=0.022), whereas ARI was lower (-16%, p=0.003), and MDR isolates were less prevalent (-65%, p=0.001). For P. multocida, odds for carrying pansusceptible isolates were higher in IF before slaughter compared to CF (+990%, p=0.009). No differences between IF and CF were seen regarding the prevalence of pansuceptible M. haemolytica. These findings indicate that easy-to-implement measures to improve calf management can lead to a limitation of AMR in Swiss veal fattening farms
Prospective Assessment of Sex-Related Differences in Symptom Status and Health Perception Among Patients With Atrial Fibrillation.
We prospectively assessed sex-specific differences in health perception, overall symptom status, and specific symptoms in a large cohort of patients with atrial fibrillation.
We performed a prospective multicenter observational cohort study of 1553 patients with atrial fibrillation. Patients completed questionnaires about personal characteristics, comorbidities, and symptoms on a yearly basis. Mean age was 70±11 years among women and 67±12 years among men. Health perception on a visual analogue scale ranging from 0 to 100 (with higher scores indicating better health perception) was significantly lower in women than in men (70 [interquartile range: 50-80] versus 75 [interquartile range: 60-85]; javax.xml.bind.JAXBElement@29592a5d <0.0001). More women than men had any symptoms (85.0% versus 68.3%; javax.xml.bind.JAXBElement@7ac0b4e4 <0.0001), palpitations (65.2% versus 44.4%; javax.xml.bind.JAXBElement@41229466 <0.0001), dizziness (25.6% versus 13.5%; javax.xml.bind.JAXBElement@61871784 <0.0001), dyspnea (35.7% versus 21.8%; javax.xml.bind.JAXBElement@16cc22b <0.0001), and fatigue (25.3% versus 19.1%; javax.xml.bind.JAXBElement@7ef43176 =0.006). At 1-year follow-up, symptoms decreased in both sexes but remained more frequent in women (49.1% versus 32.6%, javax.xml.bind.JAXBElement@2b200b6a <0.0001). In multivariable adjusted longitudinal regression models, female sex remained an independent predictor for lower health perception (ß=-4.8; 95% CI, -6.5 to -3.1; javax.xml.bind.JAXBElement@72c212bd <0.0001), any symptoms (odds ratio [OR]: 2.6; 95% CI, 2.1-3.4; javax.xml.bind.JAXBElement@15d8fb54 <0.0001), palpitations (OR: 2.6; 95% CI, 2.1-3.2; javax.xml.bind.JAXBElement@4af80718 <0.0001), dizziness (OR: 2.9; 95% CI, 2.1-3.9; javax.xml.bind.JAXBElement@61282e76 <0.0001), dyspnea (OR: 2.1; 95% CI, 1.6-2.8; javax.xml.bind.JAXBElement@31d9f14 <0.0001), fatigue (OR: 1.6; 95% CI, 1.2-2.2; javax.xml.bind.JAXBElement@51cdd678 =0.0008), and chest pain (OR: 1.8; 95% CI, 1.3-2.6; javax.xml.bind.JAXBElement@5b87db9e =0.001).
Women with atrial fibrillation have a substantially higher symptom burden and lower health perception than men. These relationships persisted after multivariable adjustment and during prospective follow-up
Transcultural adaptation and validation of a French version of the Prosthetic Limb Users Survey of Mobility 12-item Short-Form (PLUS-M/FC-12) in active amputees.
The PLUS-M 12-item Short-Form is a self-questionnaire that assesses the perceived capacity of lower limb amputees (LLAs) to perform a number of daily-life activities. Its psychometric properties are excellent (intraclass correlation coefficient [ICC]>0.9, fast administration and scoring, normative data available), and it can be used in clinical practice or for research purposes.
We aimed to develop a French version of this questionnaire and to assess its psychometric properties.
We followed international recommendations for translation and cross-cultural validation of questionnaires. In total, 52 LLAs (age 53±16, 40 males, 28/12/12 transtibial/Gritti-Stokes/transfemoral, 20/28/4 ischemic/traumatic/other) participated. Criterion and construct validities were assessed with the Pearson correlation coefficient (PCC) between the PLUS-M 12-item Short-Form and other constructs (Prosthetic-Profile-of-the-Amputee-Locomotor Capabilities Index, Activities-specific Balance Confidence scale, 2-min walking test and Timed Up and Go test), internal consistency with the Cronbach α and reliability with the ICC in 46 individuals who completed the questionnaire twice in a 7-day interval.
The mean (SD) PLUS-M 12-item Short-Form T-score was 56.1 (7.8; range 40.3 to 71.4). Construct and criterion validity, internal consistency and reliability ranged from low to excellent (r=0.43 to 0.84, P<10 <sup>-2</sup> to 0.002; Cronbach α=0.90, ICC=0.89 [0.81-0.94]). We found no floor or ceiling effect.
The French version of the PLUS-M 12-item Short-Form has good to excellent psychometric properties, comparable to those of the original version. Its use could definitely be proposed for both clinical and research purposes, once its validation is completed by assessing other psychometric qualities, especially sensitivity to change
Selective probing of hidden spin-polarized states in inversion-symmetric bulk
Spin- and angle-resolved photoemission spectroscopy is used to reveal that a large spin polarization is observable in the bulk centrosymmetric transition metal dichalcogenide MoS2. It is found that the measured spin polarization can be reversed by changing the handedness of incident circularly polarized light. Calculations based on a three-step model of photoemission show that the valley and layer-locked spin- polarized electronic states can be selectively addressed by circularly polarized light, therefore providing a novel route to probe these hidden spin-polarized states in inversion-symmetric systems as predicted by Zhang et al. [Nat. Phys. 10, 387 (2014).]
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