2,261 research outputs found
On the zero crossing of the three-gluon vertex
We report on new results on the infrared behaviour of the three-gluon vertex
in quenched Quantum Chormodynamics, obtained from large-volume lattice
simulations. The main focus of our study is the appearance of the
characteristic infrared feature known as 'zero crossing', the origin of which
is intimately connected with the nonperturbative masslessness of the
Faddeev-Popov ghost. The appearance of this effect is clearly visible in one of
the two kinematic configurations analyzed, and its theoretical origin is
discussed in the framework of Schwinger-Dyson equations. The effective coupling
in the momentum subtraction scheme that corresponds to the three-gluon vertex
is constructed, revealing the vanishing of the effective interaction at the
exact location of the zero crossing.Comment: 6 pages, 4 figure
Instanton liquid properties from lattice QCD
We examined the instanton contribution to the QCD configurations generated from lattice QCD for N-F = 0, N-F = 2 + 1 and NF = 2 + 1 + 1 dynamical quark flavors from two different and complementary approaches. First via the use of Gradient flow, we computed instanton liquid properties using an algorithm to localize instantons in the gauge field con figurations and studied their evolution with flow time. Then, the analysis of the running at low momenta of gluon Green\u27s functions serves as an independent confirmation of the instanton density which can also be derived without the use of the Gradient flow
Protective effects of eicosapentaenoic acid plus hydroxytyrosol supplementation against white adipose tissue abnormalities in mice fed a high-fat diet
Objective: Obesity induced by high-fat diet (HFD) elicits white adipose tissue dysfunction. In this study, we have hypothesized that the metabolic modulator eicosapentaenoic acid (EPA) combined with the antioxidant hydroxytyrosol (HT) attenuates HFD-induced white adipose tissue (WAT) alterations. Methods: C57BL/6J mice were administered with a HFD (60% fat, 20% protein, 20% carbohydrates) or control diet (CD; 10% fat, 20% protein, 70% carbohydrates), with or without EPA (50 mg/kg/day), HT (5 mg/kg/day), or both for 12 weeks. Determinations in WAT include morphological parameters, EPA and docosahexaenoic acid content in phospholipids (gas chromatography), lipogenesis, oxidative stress (OS) and inflammation markers, and gene expression and activities of transcription factors, such as sterol regulatory element-binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor-gamma (PPAR-Îł), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ÎșB) (p65 subunit) and nuclear factor erythroid 2-related factor 2 (Nrf2) (quantitative polymerase chain reaction and enzyme linked immunosorbent assay). Results: HFD led to WAT hypertrophy in relation to PPAR-Îł downregulation. WAT metabolic dysfunction was characterized by upregulation of lipogenic SREBP-1c system, mitochondrial energy metabolism depression, loss of the antioxidant Nrf2 signaling with OS enhancement, n-3 long-chain polyunsaturated fatty acids depletion and activation of the pro-inflammatory NF-ÎșB system. EPA and HT co-supplementation diminished HFD-dependent effects additively, reaching values close or similar to controls. Conclusion: Data presented strengthen the importance of combined protocols such as EPA plus HT to attenuate metabolic-inflammatory states triggered by obesity
Epitaxial InN/InGaN quantum dots on Si: Cl- anion selectivity and pseudocapacitor behavior
Epitaxial InN quantum dots (QDs) on In-rich InGaN, applied as an electrochemical electrode, activate Clâ-anion-selective surface attachment, bringing forth faradaic/pseudocapacitor-like behavior. In contrast to traditional pseudocapacitance, here, no chemical reaction of the electrode material occurs. The anion attachment is explained by the unique combination of the surface and quantum properties of the InN QDs. A high areal capacitance is obtained for this planar electrode together with rapid and reversible charge/discharge cycles. With the growth on cheap Si substrates, the InN/InGaN QD electrochemical electrode has great potential, opening up new application fields for IIIânitride semiconductors
Ambulatory blood pressure monitoring during pregnancy: an Italian experience
Objective: To describe the impact of a collaborative Italian diagnostic pathway offering ambulatory blood pressure (BP) monitoring (ABPM) in High Risk Antenatal Clinic (HRAC) pregnant women. The study included 395 pregnant women evaluated at HRAC between 2012 and 2016, while analyzing demographic, clinical characteristics, and prescription of ABPM. Pregnant women were firstly seen when gestational age was 19.6 +/- 9.6 weeks. In at least one-third of cases, ABPM was followed by medical intervention aiming to modify the preexisting therapeutic treatment. Hypertension and overweight were the main reasons for performing ABPM. WCH: white-coat hypertension
Dynamical approach to the Casimir effect
Casimir forces can appear between intrusions placed in different media driven
by several fluctuation mechanisms, either in equilibrium or out of it. Herein,
we develop a general formalism to obtain such forces from the dynamical
equations of the fluctuating medium, the statistical properties of the driving
noise, and the boundary conditions of the intrusions (which simulate the
interaction between the intrusions and the medium). As a result, an explicit
formula for the Casimir force over the intrusions is derived. This formalism
contains the thermal Casimir effect as a particular limit and generalizes the
study of the Casimir effect to such systems through their dynamical equations,
with no appeal to their Hamiltonian, if any exists. In particular, we study the
Casimir force between two infinite parallel plates with Dirichlet or Neumann
boundary conditions, immersed in several media with finite correlation lengths
(reaction--diffusion system, liquid crystals, and two coupled fields with
non-Hermitian evolution equations). The driving Gaussian noises have vanishing
or finite spatial or temporal correlation lengths; in the first case,
equilibrium is reobtained and finite correlations produce nonequilibrium
dynamics. The results obtained show that, generally, nonequilibrium dynamics
leads to Casimir forces, whereas Casimir forces are obtained in equilibrium
dynamics if the stress tensor is anisotropic.Comment: 12 pages, 1 figur
Porcine colonization of the Americas: a 60k SNP story.
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Weaker HLA footprints on HIV in the unique and highly genetically admixed host population of Mexico
HIV circumvents HLA class I-restricted CD8+ T-cell responses through selection of escape mutations that leave characteristic mutational âfootprints,â also known as HLA-associated polymorphisms (HAPs), on HIV sequences at the population level. While many HLA footprints are universal across HIV subtypes and human populations, others can be region specific as a result of the unique immunogenetic background of each host population. Using a published probabilistic phylogenetically informed model, we compared HAPs in HIV Gag and Pol (PR-RT) in 1,612 subtype B-infected, antiretroviral treatment-naive individuals from Mexico and 1,641 individuals from Canada/United States. A total of 252 HLA class I allele subtypes were represented, including 140 observed in both cohorts, 67 unique to Mexico, and 45 unique to Canada/United States. At the predefined statistical threshold of a q value of <0.2, 358 HAPs (201 in Gag, 157 in PR-RT) were identified in Mexico, while 905 (534 in Gag and 371 in PR-RT) were identified in Canada/United States. HAPs identified in Mexico included both canonical HLA-associated escape pathways and novel associations, in particular with HLA alleles enriched in Amerindian and mestizo populations. Remarkably, HLA footprints on HIV in Mexico were not only fewer but also, on average, significantly weaker than those in Canada/United States, although some exceptions were noted. Moreover, exploratory analyses suggested that the weaker HLA footprint on HIV in Mexico may be due, at least in part, to weaker and/or less reproducible HLA-mediated immune pressures on HIV in this population. The implications of these differences for natural and vaccine-induced anti-HIV immunity merit further investigation
The Infrared Behaviour of the Pure Yang-Mills Green Functions
We review the infrared properties of the pure Yang-Mills correlators and
discuss recent results concerning the two classes of low-momentum solutions for
them reported in literature; i.e. decoupling and scaling solutions. We will
mainly focuss on the Landau gauge and pay special attention to the results
inferred from the analysis of the Dyson-Schwinger equations of the theory and
from "{\it quenched}" lattice QCD. The results obtained from properly
interplaying both approaches are strongly emphasized.Comment: Final version to be published in FBS (54 pgs., 11 figs., 4 tabs
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