5,975 research outputs found
Chiral corrections to the Gell-Mann-Oakes-Renner relation
The next to leading order chiral corrections to the
Gell-Mann-Oakes-Renner (GMOR) relation are obtained using the pseudoscalar
correlator to five-loop order in perturbative QCD, together with new finite
energy sum rules (FESR) incorporating polynomial, Legendre type, integration
kernels. The purpose of these kernels is to suppress hadronic contributions in
the region where they are least known. This reduces considerably the systematic
uncertainties arising from the lack of direct experimental information on the
hadronic resonance spectral function. Three different methods are used to
compute the FESR contour integral in the complex energy (squared) s-plane, i.e.
Fixed Order Perturbation Theory, Contour Improved Perturbation Theory, and a
fixed renormalization scale scheme. We obtain for the corrections to the GMOR
relation, , the value . This result
is substantially more accurate than previous determinations based on QCD sum
rules; it is also more reliable as it is basically free of systematic
uncertainties. It implies a light quark condensate . As a byproduct, the chiral perturbation theory (unphysical) low energy
constant is predicted to be , or .Comment: A comment about the value of the strong coupling has been added at
the end of Section 4. No change in results or conslusion
Sequence analysis and expression of genes involved cytoskeleton and infection mechanisms in the plant pathogen Phytophthora cinnamomi
Oomycetes from the genus Phytophthora are plant pathogens that are devastating for agriculture and natural ecosystems. The biggest productivity and yield break occurs due to the ink disease; caused by Phytophthora cinnamomi, which is one of the most widely distributed Phytophthora species, with nearly 1 000 host species. The knowledge about the molecular mechanisms responsible for its pathogenicity is an important tool in order to fight diseases associated with this pathogen
The origin of the Acheulean: the 1.7 million-year-old site of FLK West, Olduvai Gorge (Tanzania)
The appearance of the Acheulean is one of the hallmarks of human evolution. It represents the
emergence of a complex behavior, expressed in the recurrent manufacture of large-sized tools, with
standardized forms, implying more advance forethought and planning by hominins than those required
by the precedent Oldowan technology. The earliest known evidence of this technology dates back to
c. 1.7 Ma. and is limited to two sites (Kokiselei [Kenya] and Konso [Ethiopia]), both of which lack fauna.
The functionality of these earliest Acheulean assemblages remains unknown. Here we present the
discovery of another early Acheulean site also dating to c. 1.7 Ma from Olduvai Gorge. This site provides
evidence of the earliest steps in developing the Acheulean technology and is the oldest Acheulean site in
which stone tools occur spatially and functionally associated with the exploitation of fauna. Simple and
elaborate large-cutting tools (LCT) and handaxes co-exist at FLK West, showing that complex cognition
was present from the earliest stages of the Acheulean. Here we provide a detailed technological study
and evidence of the use of these tools on the butchery and consumption of fauna, probably by early
Homo erectus sensu lato
The role of statins on helicobacter pylori eradication: Results from the european registry on the management of h. pylori (hp-eureg)
Statins could increase the effectiveness of Helicobacter pylori eradication therapies due to their anti-inflammatory effect. The aim of this study was to analyze the impact of this therapeutic association in real life. This is a multicenter, prospective, non-interventional study aimed at evaluating the management of H. pylori by European gastroenterologists. Patients were registered in an e-CRF by AEG-REDCap from 2013 to 2020. The association between statin use and H. pylori eradication effectiveness was evaluated through multivariate analysis. Overall, 9988 and 705 patients received empirical and culture-guided treatment, respectively. Overall, statin use was associated with higher effectiveness in the empirical group (OR = 1.3; 95%CI = 1.1-1.5), but no association was found with first-line treatment effectiveness (N = 7738); as an exception, statin use was specifically associated with lower effectiveness of standard triple therapy (OR = 0.76; 95%CI = 0.59-0.99). In the rescue therapy empirical group (N = 2228), statins were associated with higher overall effectiveness (OR = 1.9; 95%CI = 1.4-2.6). However, sub-analyses by treatment schemes only confirmed this association for the single-capsule bismuth quadruple therapy (OR = 2.8; 95%CI = 1.3-5.7). No consistent association was found between statin use and H. pylori therapy effectiveness. Therefore, the addition of statins to the usual H. pylori treatment cannot be currently recommended to improve cure rates. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Inclusive Search for Anomalous Production of High-pT Like-Sign Lepton Pairs in Proton-Antiproton Collisions at sqrt{s}=1.8 TeV
We report on a search for anomalous production of events with at least two
charged, isolated, like-sign leptons with pT > 11 GeV/c using a 107 pb^-1
sample of 1.8 TeV ppbar collisions collected by the CDF detector. We define a
signal region containing low background from Standard Model processes. To avoid
bias, we fix the final cuts before examining the event yield in the signal
region using control regions to test the Monte Carlo predictions. We observe no
events in the signal region, consistent with an expectation of
0.63^(+0.84)_(-0.07) events. We present 95% confidence level limits on new
physics processes in both a signature-based context as well as within a
representative minimal supergravity (tanbeta = 3) model.Comment: 15 pages, 4 figures. Minor textual changes, cosmetic improvements to
figures and updated and expanded reference
A Molecular Characterization of the Allelic Expression of the BRCA1 Founder Δ9–12 Pathogenic Variant and Its Potential Clinical Relevance in Hereditary Cancer:International Journal of Molecular Sciences
Hereditary breast and ovarian cancer (HBOC) syndrome is a genetic condition that increases the risk of breast cancer by 80% and that of ovarian cancer by 40%. The most common pathogenic variants (PVs) causing HBOC occur in the BRCA1 gene, with more than 3850 reported mutations in the gene sequence. The prevalence of specific PVs in BRCA1 has increased across populations due to the effect of founder mutations. Therefore, when a founder mutation is identified, it becomes key to improving cancer risk characterization and effective screening protocols. The only founder mutation described in the Mexican population is the deletion of exons 9 to 12 of BRCA1 (BRCA1Δ9–12), and its description focuses on the gene sequence, but no transcription profiles have been generated for individuals who carry this gene. In this study, we describe the transcription profiles of cancer patients and healthy individuals who were heterozygous for PV BRCA1Δ9–12 by analyzing the differential expression of both alleles compared with the homozygous BRCA1 control group using RT–qPCR, and we describe the isoforms produced by the BRCA1 wild-type and BRCA1Δ9–12 alleles using nanopore long-sequencing. Using the Kruskal–Wallis test, our results showed a similar transcript expression of the wild-type allele between the healthy heterozygous group and the homozygous BRCA1 control group. An association between the recurrence and increased expression of both alleles in HBOC patients was also observed. An analysis of the sequences indicated four wild-type isoforms with diagnostic potential for discerning individuals who carry the PV BRCA1Δ9–12 and identifying which of them has developed cancer
Role of proton pump inhibitors dosage and duration in Helicobacter pylori eradication treatment: Results from the European Registry on H. pylori management
Background: Management of Helicobacter pylori (H. pylori) infection requires co-treatment with proton pump inhibitors (PPIs) and the use of antibiotics to achieve successful eradication. Aim: To evaluate the role of dosage of PPIs and the duration of therapy in the effectiveness of H. pylori eradication treatments based on the ‘European Registry on Helicobacter pylori management’ (Hp-EuReg). Methods: Hp-EuReg is a multicentre, prospective, non-interventionist, international registry on the routine clinical practice of H. pylori management by European gastroenterologists. All infected adult patients were systematically registered from 2013 to 2022. Results: Overall, 36,579 patients from five countries with more than 1000 patients were analysed. Optimal (≥90%) first-line-modified intention-to-treat effectiveness was achieved with the following treatments: (1) 14-day therapies with clarithromycin-amoxicillin-bismuth and metronidazole-tetracycline-bismuth, both independently of the PPI dose prescribed; (2) All 10-day (except 10-day standard triple therapy) and 14-day therapies with high-dose PPIs; and (3) 10-day quadruple therapies with clarithromycin-amoxicillin-bismuth, metronidazole-tetracycline-bismuth, and clarithromycin-amoxicillin-metronidazole (sequential), all with standard-dose PPIs. In first-line treatment, optimal effectiveness was obtained with high-dose PPIs in all 14-day treatments, in 10- and 14-day bismuth quadruple therapies and in 10-day sequential with standard-dose PPIs. Optimal second-line effectiveness was achieved with (1) metronidazole-tetracycline-bismuth quadruple therapy for 14- and 10 days with standard and high-dose PPIs, respectively; and (2) levofloxacin-amoxicillin triple therapy for 14 days with high-dose PPIs. None of the 7-day therapies in both treatment lines achieved optimal effectiveness. Conclusions: We recommend, in first-line treatment, the use of high-dose PPIs in 14-day triple therapy and in 10-or 14-day quadruple concomitant therapy in first-line treatment, while standard-dose PPIs would be sufficient in 10-day bismuth quadruple therapies. On the other hand, in second-line treatment, high-dose PPIs would be more beneficial in 14-day triple therapy with levofloxacin and amoxicillin or in 10-day bismuth quadruple therapy either as a three-in-one single capsule or in the traditional scheme
Measurement of and Production in Collisions at = 1.96 TeV
The Standard Model predictions for and production are
tested using an integrated luminosity of 200 pb of \ppbar collision data
collected at the Collider Detector at Fermilab. The cross sections are measured
selecting leptonic decays of the and bosons, and photons with
transverse energy GeV that are well separated from leptons. The
production cross sections and kinematic distributions for the and
are compared to SM predictions.Comment: 7 pages, 4 figures, submitted to PR
Search for Narrow Diphoton Resonances and for gamma-gamma+W/Z Signatures in p\bar p Collisions at sqrt(s)=1.8 TeV
We present results of searches for diphoton resonances produced both
inclusively and also in association with a vector boson (W or Z) using 100
pb^{-1} of p\bar p collisions using the CDF detector. We set upper limits on
the product of cross section times branching ratio for both p\bar
p\to\gamma\gamma + X and p\bar p\to\gamma\gamma + W/Z. Comparing the inclusive
production to the expectations from heavy sgoldstinos we derive limits on the
supersymmetry-breaking scale sqrt{F} in the TeV range, depending on the
sgoldstino mass and the choice of other parameters. Also, using a NLO
prediction for the associated production of a Higgs boson with a W or Z boson,
we set an upper limit on the branching ratio for H\to\gamma\gamma. Finally, we
set a lower limit on the mass of a `bosophilic' Higgs boson (e.g. one which
couples only to \gamma, W, and Z$ bosons with standard model couplings) of 82
GeV/c^2 at 95% confidence level.Comment: 30 pages, 11 figure
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