33 research outputs found
Model-independent evidence for contributions to decays
The data sample of decays acquired with the
LHCb detector from 7 and 8~TeV collisions, corresponding to an integrated
luminosity of 3 fb, is inspected for the presence of or
contributions with minimal assumptions about
contributions. It is demonstrated at more than 9 standard deviations that
decays cannot be described with
contributions alone, and that contributions play a dominant role in
this incompatibility. These model-independent results support the previously
obtained model-dependent evidence for charmonium-pentaquark
states in the same data sample.Comment: 21 pages, 12 figures (including the supplemental section added at the
end
Quantum numbers of the state and orbital angular momentum in its decay
Angular correlations in decays, with , and , are used to measure
orbital angular momentum contributions and to determine the value of
the meson. The data correspond to an integrated luminosity of 3.0
fb of proton-proton collisions collected with the LHCb detector. This
determination, for the first time performed without assuming a value for the
orbital angular momentum, confirms the quantum numbers to be .
The is found to decay predominantly through S wave and an upper limit
of at C.L. is set on the fraction of D wave.Comment: 16 pages, 4 figure
Observation of Z production in proton-lead collisions at LHCb
The first observation of Z boson production in proton-lead collisions at a centre-of-mass energy per proton-nucleon pair of root(s) N N = 5TeV is presented. The data sample corresponds to an integrated luminosity of 1.6 nb(-1) collected with the LHCb detector. The Z candidates are reconstructed from pairs of oppositely charged muons with pseudorapidities between 2.0 and 4.5 and transverse momenta above 20 GeV/c. The invariant dimuon mass is restricted to the range 60-120 GeV/c. The Z production cross-section is measured to be sigma(Z ->mu+mu-) (fwd) = 13.5(-4.0)(+5.4)(stat.) +/- 1.2(syst.) nb in the direction of the proton beam and sigma(Z ->mu+mu-) (bwd) = 10.7(-5.1)(+8.4)(stat.) +/- 1.0(syst.) nb in the direction of the lead beam, where the first uncertainty is statistical and the second systematic
Measurement of the branching fraction and angular amplitudes
A search for the decay with is performed with 0.37 fb of collisions at
= 7 TeV collected by the LHCb experiment, finding a \Bs \to J\psi
K^-\pi^+ peak of signal events. The mass spectrum of
the candidates in the peak is dominated by the contribution.
Subtracting the non-resonant component, the branching fraction of
\BsJpsiKst is , where the first
uncertainty is statistical and the second systematic. A fit to the angular
distribution of the decay products yields the \Kst polarization fractions and
Measurement of Upsilon production in pp collisions at \sqrt{s} = 7 TeV
The production of Upsilon(1S), Upsilon(2S) and Upsilon(3S) mesons in
proton-proton collisions at the centre-of-mass energy of sqrt(s)=7 TeV is
studied with the LHCb detector. The analysis is based on a data sample of 25
pb-1 collected at the Large Hadron Collider. The Upsilon mesons are
reconstructed in the decay mode Upsilon -> mu+ mu- and the signal yields are
extracted from a fit to the mu+ mu- invariant mass distributions. The
differential production cross-sections times dimuon branching fractions are
measured as a function of the Upsilon transverse momentum pT and rapidity y,
over the range pT < 15 GeV/c and 2.0 < y < 4.5. The cross-sections times
branching fractions, integrated over these kinematic ranges, are measured to be
sigma(pp -> Upsilon(1S) X) x B(Upsilon(1S)->mu+ mu-) = 2.29 {\pm} 0.01 {\pm}
0.10 -0.37 +0.19 nb, sigma(pp -> Upsilon(2S) X) x B(Upsilon(2S)->mu+ mu-) =
0.562 {\pm} 0.007 {\pm} 0.023 -0.092 +0.048 nb, sigma(pp -> Upsilon(3S) X) x
B(Upsilon(3S)->mu+ mu-) = 0.283 {\pm} 0.005 {\pm} 0.012 -0.048 +0.025 nb, where
the first uncertainty is statistical, the second systematic and the third is
due to the unknown polarisation of the three Upsilon states.Comment: 22 pages, 7 figure
Evidence for CP violation in time-integrated D0 -> h-h+ decay rates
A search for time-integrated CP violation in D0 -> h-h+ (h=K, pi) decays is
presented using 0.62 fb^-1 of data collected by LHCb in 2011. The flavor of the
charm meson is determined by the charge of the slow pion in the D*+ -> D0 pi+
and D*- -> D0bar pi- decay chains. The difference in CP asymmetry between D0 ->
K-K+ and D0 -> pi-pi+, Delta ACP = ACP(K-K+) - ACP(pi-pi+), is measured to be
[-0.82 \pm 0.21(stat.) \pm 0.11(syst.)]%. This differs from the hypothesis of
CP conservation by 3.5 standard deviations.Comment: 8 pages, 3 figures, 2 tables; v2 minor updates after journal revie
Population and fertility by age and sex for 195 countries and territories, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017
Background: Population estimates underpin demographic and epidemiological research and are used to track progress on numerous international indicators of health and development. To date, internationally available estimates of population and fertility, although useful, have not been produced with transparent and replicable methods and do not use standardised estimates of mortality. We present single-calendar year and single-year of age estimates of fertility and population by sex with standardised and replicable methods. Methods: We estimated population in 195 locations by single year of age and single calendar year from 1950 to 2017 with standardised and replicable methods. We based the estimates on the demographic balancing equation, with inputs of fertility, mortality, population, and migration data. Fertility data came from 7817 location-years of vital registration data, 429 surveys reporting complete birth histories, and 977 surveys and censuses reporting summary birth histories. We estimated age-specific fertility rates (ASFRs; the annual number of livebirths to women of a specified age group per 1000 women in that age group) by use of spatiotemporal Gaussian process regression and used the ASFRs to estimate total fertility rates (TFRs; the average number of children a woman would bear if she survived through the end of the reproductive age span [age 10–54 years] and experienced at each age a particular set of ASFRs observed in the year of interest). Because of sparse data, fertility at ages 10–14 years and 50–54 years was estimated from data on fertility in women aged 15–19 years and 45–49 years, through use of linear regression. Age-specific mortality data came from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 estimates. Data on population came from 1257 censuses and 761 population registry location-years and were adjusted for underenumeration and age misreporting with standard demographic methods. Migration was estimated with the GBD Bayesian demographic balancing model, after incorporating information about refugee migration into the model prior. Final population estimates used the cohort-component method of population projection, with inputs of fertility, mortality, and migration data. Population uncertainty was estimated by use of out-of-sample predictive validity testing. With these data, we estimated the trends in population by age and sex and in fertility by age between 1950 and 2017 in 195 countries and territories. Findings: From 1950 to 2017, TFRs decreased by 49\ub74% (95% uncertainty interval [UI] 46\ub74–52\ub70). The TFR decreased from 4\ub77 livebirths (4\ub75–4\ub79) to 2\ub74 livebirths (2\ub72–2\ub75), and the ASFR of mothers aged 10–19 years decreased from 37 livebirths (34–40) to 22 livebirths (19–24) per 1000 women. Despite reductions in the TFR, the global population has been increasing by an average of 83\ub78 million people per year since 1985. The global population increased by 197\ub72% (193\ub73–200\ub78) since 1950, from 2\ub76 billion (2\ub75–2\ub76) to 7\ub76 billion (7\ub74–7\ub79) people in 2017; much of this increase was in the proportion of the global population in south Asia and sub-Saharan Africa. The global annual rate of population growth increased between 1950 and 1964, when it peaked at 2\ub70%; this rate then remained nearly constant until 1970 and then decreased to 1\ub71% in 2017. Population growth rates in the southeast Asia, east Asia, and Oceania GBD super-region decreased from 2\ub75% in 1963 to 0\ub77% in 2017, whereas in sub-Saharan Africa, population growth rates were almost at the highest reported levels ever in 2017, when they were at 2\ub77%. The global average age increased from 26\ub76 years in 1950 to 32\ub71 years in 2017, and the proportion of the population that is of working age (age 15–64 years) increased from 59\ub79% to 65\ub73%. At the national level, the TFR decreased in all countries and territories between 1950 and 2017; in 2017, TFRs ranged from a low of 1\ub70 livebirths (95% UI 0\ub79–1\ub72) in Cyprus to a high of 7\ub71 livebirths (6\ub78–7\ub74) in Niger. The TFR under age 25 years (TFU25; number of livebirths expected by age 25 years for a hypothetical woman who survived the age group and was exposed to current ASFRs) in 2017 ranged from 0\ub708 livebirths (0\ub707–0\ub709) in South Korea to 2\ub74 livebirths (2\ub72–2\ub76) in Niger, and the TFR over age 30 years (TFO30; number of livebirths expected for a hypothetical woman ageing from 30 to 54 years who survived the age group and was exposed to current ASFRs) ranged from a low of 0\ub73 livebirths (0\ub73–0\ub74) in Puerto Rico to a high of 3\ub71 livebirths (3\ub70–3\ub72) in Niger. TFO30 was higher than TFU25 in 145 countries and territories in 2017. 33 countries had a negative population growth rate from 2010 to 2017, most of which were located in central, eastern, and western Europe, whereas population growth rates of more than 2\ub70% were seen in 33 of 46 countries in sub-Saharan Africa. In 2017, less than 65% of the national population was of working age in 12 of 34 high-income countries, and less than 50% of the national population was of working age in Mali, Chad, and Niger. Interpretation: Population trends create demographic dividends and headwinds (ie, economic benefits and detriments) that affect national economies and determine national planning needs. Although TFRs are decreasing, the global population continues to grow as mortality declines, with diverse patterns at the national level and across age groups. To our knowledge, this is the first study to provide transparent and replicable estimates of population and fertility, which can be used to inform decision making and to monitor progress. Funding: Bill & Melinda Gates Foundation
Dieta de Hemidactylus frenatus (Sauria: Gekkonidae) en un \ue1rea urbana de la regi\uf3n caribe colombiana
The aim of this work was to study the diet of Hemidactylus frenatus in an urban area of Colombian Caribbean region. Twenty five specimens were captured on human edifications at the Sincelejo municipality (Sucre). After dissection and analysis of the stomach content, we identify 12 prey groups being Hemiptera the item with the highest importance value index (IVI = 152.7). The data shows a generalist and opportunistic feeding pattern, feeding mainly on arthropods
The G Protein-Coupled Receptor Heterodimer Network (GPCR-HetNet) and Its Hub Components.
G protein-coupled receptors (GPCRs) oligomerization has emerged as a vital characteristic of receptor structure. Substantial experimental evidence supports the existence of GPCR-GPCR interactions in a coordinated and cooperative manner. However, despite the current development of experimental techniques for large-scale detection of GPCR heteromers, in order to understand their connectivity it is necessary to develop novel tools to study the global heteroreceptor networks. To provide insight into the overall topology of the GPCR heteromers and identify key players, a collective interaction network was constructed. Experimental interaction data for each of the individual human GPCR protomers was obtained manually from the STRING and SCOPUS databases. The interaction data were used to build and analyze the network using Cytoscape software. The network was treated as undirected throughout the study. It is comprised of 156 nodes, 260 edges and has a scale-free topology. Connectivity analysis reveals a significant dominance of intrafamily versus interfamily connections. Most of the receptors within the network are linked to each other by a small number of edges. DRD2, OPRM, ADRB2, AA2AR, AA1R, OPRK, OPRD and GHSR are identified as hubs. In a network representation 10 modules/clusters also appear as a highly interconnected group of nodes. Information on this GPCR network can improve our understanding of molecular integration. GPCR-HetNet has been implemented in Java and is freely available at http://www.iiia.csic.es/~ismel/GPCR-Nets/index.html
Assessment of human health hazards associated with the dietary exposure to organic and inorganic contaminants through the consumption of fishery products in Spain
In this work we have evaluated the potential carcinogenic and acutely toxic risks associated to the exposure to highly prevalent organic and inorganic contaminants through the consumption of fishery products by the Spanish population. The concentrations of 8 organochlorine pesticides (OCPs), 18 polychlorinated biphenils (PCBs), 7 polycyclic aromatic hydrocarbons (expressed as benzo[a]pyrene toxic equivalents (B[a]Peq)), and three inorganic toxic elements [arsenic (As), cadmium (Cd), and mercury (Hg)] were determined in 93 samples of the most consumed species of white fish, blue fish, cephalopods and seafood species, which were acquired directly in markets and supermarkets in the Canary Islands, Spain. The chemical concentration data were combined with the pattern of consumption of these foodstuffs in order to calculate the daily intake of these contaminants, and on this basis the risk quotients for carcinogenicity and acute toxicity were determined for Spanish adults and children. Our results showed that the daily intake of OCPs, PCBs and B[a]Peq, which is associated to blue fish consumption was the highest within the fish group. The estimated intake of pollutants can be considered low or very low for the individual contaminants, when compared to reference values, except in the case of HCB and As. All the estimated intakes were below the reported Tolerable Daily Intakes. Considering the additive effects of multiple contaminants, the risk of acute toxic effects can also be considered as low or very low. However, our results reflect that the current consumption of white fish in adults and children, and also the blue fish in the case of adults, poses a moderate carcinogenic risk to Spanish consumers, mainly related to their concentrations of As. The conclusions of this research may be useful for the design of appropriate risk communication campaigns