50 research outputs found
Towards a new paradigm for heavy-light meson spectroscopy
Since 2003 many new hadrons, including the lowest-lying positive-parity
charm-strange mesons and , were observed
that do not conform with quark model expectations. It was recently demonstrated
that various puzzles in the charm meson spectrum find a natural resolution, if
the SU(3) multiplets for the lightest scalar and axial-vector states, amongst
them the and the , owe their existence to
the nonperturbative dynamics of Goldstone-Boson scattering off and
mesons. Most importantly the ordering of the lightest strange and
nonstrange scalars becomes natural. In this work we demonstrate for the first
time that this mechanism is strongly supported by the recent high quality data
on the provided by the LHCb experiment. This implies
that the lowest quark-model positive-parity charm mesons, together with their
bottom counterparts, if realized in nature, do not form the ground-state
multiplet. This is similar to the pattern that has been established for the
scalar mesons made from light up, down and strange quarks, where the lowest
multiplet is considered to be made of states not described by the quark model.
In a broader view, the hadron spectrum must be viewed as more than a collection
of quark model states.Comment: 8 pages, 5 figures. Discussion significantly extended, suggestion for
lattice and more comparison with LHCb data added; version accepted for
publication in PR
The negative-parity spin-1/2 baryon spectrum from lattice QCD and effective theory
The spectrum of the negative-parity spin-1/2 baryons is studied
using lattice QCD and hadronic effective theory in a unitarized coupled-channel
framework. A direct comparison between the two approaches is possible by
considering the hadronic effective theory in a finite volume and with hadron
masses and mesonic decay constants that correspond to the situation studied on
the lattice. Comparing the energy level spectrum and flavor
decompositions of the individual states, it is found that the lowest two states
extracted from lattice QCD can be identified with one of the two
-poles and the resonance. The quark mass
dependences of these two lattice QCD levels are in good agreement with their
effective theory counterparts. However, as current lattice QCD studies still
rely on three-quark operators to generate the physical states, clear signals
corresponding to the meson-baryon scattering states, that appear in the finite
volume effective theory calculation, are not yet seen.Comment: 10 pages, 6 figure
Dual activation of pathways regulated by steroid receptors and peptide growth factors in primary prostate cancer revealed by Factor Analysis of microarray data
BACKGROUND: We use an approach based on Factor Analysis to analyze datasets generated for transcriptional profiling. The method groups samples into biologically relevant categories, and enables the identification of genes and pathways most significantly associated to each phenotypic group, while allowing for the participation of a given gene in more than one cluster. Genes assigned to each cluster are used for the detection of pathways predominantly activated in that cluster by finding statistically significant associated GO terms. We tested the approach with a published dataset of microarray experiments in yeast. Upon validation with the yeast dataset, we applied the technique to a prostate cancer dataset. RESULTS: Two major pathways are shown to be activated in organ-confined, non-metastatic prostate cancer: those regulated by the androgen receptor and by receptor tyrosine kinases. A number of gene markers (HER3, IQGAP2 and POR1) highlighted by the software and related to the later pathway have been validated experimentally a posteriori on independent samples. CONCLUSION: Using a new microarray analysis tool followed by a posteriori experimental validation of the results, we have confirmed several putative markers of malignancy associated with peptide growth factor signalling in prostate cancer and revealed others, most notably ERRB3 (HER3). Our study suggest that, in primary prostate cancer, HER3, together or not with HER4, rather than in receptor complexes involving HER2, could play an important role in the biology of these tumors. These results provide new evidence for the role of receptor tyrosine kinases in the establishment and progression of prostate cancer
Dual activation of pathways regulated by steroid receptors and peptide growth factors in primary prostate cancer revealed by Factor Analysis of microarray data
BACKGROUND: We use an approach based on Factor Analysis to analyze datasets generated for transcriptional profiling. The method groups samples into biologically relevant categories, and enables the identification of genes and pathways most significantly associated to each phenotypic group, while allowing for the participation of a given gene in more than one cluster. Genes assigned to each cluster are used for the detection of pathways predominantly activated in that cluster by finding statistically significant associated GO terms. We tested the approach with a published dataset of microarray experiments in yeast. Upon validation with the yeast dataset, we applied the technique to a prostate cancer dataset. RESULTS: Two major pathways are shown to be activated in organ-confined, non-metastatic prostate cancer: those regulated by the androgen receptor and by receptor tyrosine kinases. A number of gene markers (HER3, IQGAP2 and POR1) highlighted by the software and related to the later pathway have been validated experimentally a posteriori on independent samples. CONCLUSION: Using a new microarray analysis tool followed by a posteriori experimental validation of the results, we have confirmed several putative markers of malignancy associated with peptide growth factor signalling in prostate cancer and revealed others, most notably ERRB3 (HER3). Our study suggest that, in primary prostate cancer, HER3, together or not with HER4, rather than in receptor complexes involving HER2, could play an important role in the biology of these tumors. These results provide new evidence for the role of receptor tyrosine kinases in the establishment and progression of prostate cancer
The physics potential of a reactor neutrino experiment with Skipper CCDs: Measuring the weak mixing angle
We analyze in detail the physics potential of an experiment like the one
recently proposed by the vIOLETA collaboration: a kilogram-scale Skipper CCD
detector deployed 12 meters away from a commercial nuclear reactor core. This
experiment would be able to detect coherent elastic neutrino nucleus scattering
from reactor neutrinos, capitalizing on the exceptionally low ionization energy
threshold of Skipper CCDs. To estimate the physics reach, we elect the
measurement of the weak mixing angle as a case study. We choose a realistic
benchmark experimental setup and perform variations on this benchmark to
understand the role of quenching factor and its systematic
uncertainties,background rate and spectral shape, total exposure, and reactor
antineutrino flux uncertainty. We take full advantage of the reactor flux
measurement of the Daya Bay collaboration to perform a data driven analysis
which is, up to a certain extent, independent of the theoretical uncertainties
on the reactor antineutrino flux. We show that, under reasonable assumptions,
this experimental setup may provide a competitive measurement of the weak
mixing angle at few MeV scale with neutrino-nucleus scattering.Comment: 11 pages, 6 figure
Older Adult Patients in the Emergency Department: Which Patients should be Selected for a Different Approach?
Background: While multidimensional and interdisciplinary assessment of older adult patients improves their short-term outcomes after evaluation in the emergency department (ED), this assessment is time-consuming and ill-suited for the busy environment. Thus, identifying patients who will benefit from this strategy is challenging. Therefore, this study aimed to identify older adult patients suitable for a different ED approach as well as independent variables associated with poor short-term clinical outcomes. Methods: We included all patients >= 65 years attending 52 EDs in Spain over 7 days. Sociodemographic, comorbidity, and baseline functional status data were collected. The outcomes were 30 -day mortality, re -presentation, hospital readmission, and the composite of all outcomes. Results: During the study among 96,014 patients evaluated in the ED, we included 23,338 patients >= 65 years-mean age, 78.4 +/- 8.1 years; 12,626 (54.1%) women. During follow-up, 5,776 patients (24.75%) had poor outcomes after evaluation in the ED: 1,140 (4.88%) died, 4,640 (20.51) returned to the ED, and 1,739 (7.69%) were readmitted 30 days after discharge following the index visit. A model including male sex, age >= 75 years, arrival by ambulance, Charlson Comorbidity Index >= 3, and functional impairment had a C -index of 0.81 (95% confidence interval, 0.80-0.82) for 30 -day mortality. Conclusion: Male sex, age >= 75 years, arrival by ambulance, functional impairment, or severe comorbidity are features of patients who could benefit from approaches in the ED different from the common triage to improve the poor short-term outcomes of this population
Association of Candidate Gene Polymorphisms With Chronic Kidney Disease: Results of a Case-Control Analysis in the Nefrona Cohort
Chronic kidney disease (CKD) is a major risk factor for end-stage renal disease, cardiovascular disease and premature death. Despite classical clinical risk factors for CKD and some genetic risk factors have been identified, the residual risk observed in prediction models is still high. Therefore, new risk factors need to be identified in order to better predict the risk of CKD in the population. Here, we analyzed the genetic association of 79 SNPs of proteins associated with mineral metabolism disturbances with CKD in a cohort that includes 2, 445 CKD cases and 559 controls. Genotyping was performed with matrix assisted laser desorption ionizationtime of flight mass spectrometry. We used logistic regression models considering different genetic inheritance models to assess the association of the SNPs with the prevalence of CKD, adjusting for known risk factors. Eight SNPs (rs1126616, rs35068180, rs2238135, rs1800247, rs385564, rs4236, rs2248359, and rs1564858) were associated with CKD even after adjusting by sex, age and race. A model containing five of these SNPs (rs1126616, rs35068180, rs1800247, rs4236, and rs2248359), diabetes and hypertension showed better performance than models considering only clinical risk factors, significantly increasing the area under the curve of the model without polymorphisms. Furthermore, one of the SNPs (the rs2248359) showed an interaction with hypertension, being the risk genotype affecting only hypertensive patients. We conclude that 5 SNPs related to proteins implicated in mineral metabolism disturbances (Osteopontin, osteocalcin, matrix gla protein, matrix metalloprotease 3 and 24 hydroxylase) are associated to an increased risk of suffering CKD
Comparison of seven prognostic tools to identify low-risk pulmonary embolism in patients aged <50 years
publishersversionPeer reviewe
Cost of diabetic retinopathy and macular oedema in a population, an eight year follow up
A pan-European epidemiological study reveals honey bee colony survival depends on beekeeper education and disease control
Reports of honey bee population decline has spurred many national efforts to understand the extent of the problem and to identify causative or associated factors. However, our collective understanding of the factors has been hampered by a lack of joined up trans-national effort. Moreover, the impacts of beekeeper knowledge and beekeeping management practices have often been overlooked, despite honey bees being a managed pollinator. Here, we established a standardised active monitoring network for 5 798 apiaries over two consecutive years to quantify honey bee colony mortality across 17 European countries. Our data demonstrate that overwinter losses ranged between 2% and 32%, and that high summer losses were likely to follow high winter losses. Multivariate Poisson regression models revealed that hobbyist beekeepers with small apiaries and little experience in beekeeping had double the winter mortality rate when compared to professional beekeepers. Furthermore, honey bees kept by professional beekeepers never showed signs of disease, unlike apiaries from hobbyist beekeepers that had symptoms of bacterial infection and heavy Varroa infestation. Our data highlight beekeeper background and apicultural practices as major drivers of honey bee colony losses. The benefits of conducting trans-national monitoring schemes and improving beekeeper training are discussed