994 research outputs found
An extremely low-noise heralded single-photon source: a breakthrough for quantum technologies
Low noise single-photon sources are a critical element for quantum
technologies. We present a heralded single-photon source with an extremely low
level of residual background photons, by implementing low-jitter detectors and
electronics and a fast custom-made pulse generator controlling an optical
shutter (a LiNbO3 waveguide optical switch) on the output of the source. This
source has a second-order autocorrelation g^{(2)}(0)=0.005(7), and an "Output
Noise Factor" (defined as the ratio of the number of noise photons to total
photons at the source output channel) of 0.25(1)%. These are the best
performance characteristics reported to date
Understanding the Dynamics of Ancillary Pelagic Species in the Adriatic Sea
The status of fishery resources in the Mediterranean Sea is critical: most of the fish and shellfish stocks are in overexploitation and only half of them are routinely assessed. This manuscript presents the use of Surplus Production Models (SPMs) as a valid option to increase the number of assessed stocks, with specific attention to the Adriatic basin. Particularly, the stock of European sprat (Sprattus sprattus), Mediterranean horse mackerel (Trachurus mediterraneus), and Atlantic horse mackerel (Trachurus trachurus) living in the Adriatic Sea have been evaluated comparing three SPMs: Catch Maximum Sustainable Yields (CMSY), Stochastic surplus Production model in Continuous Time (SPiCT), and Abundance Maximum Sustainable Yields (AMSY). The different approaches present some variations; however, they generally agree on describing all the stocks close to the reference values for both biomass and fishing mortality in the most recent year. For the European sprat, AMSY results are the most robust model for this speciesâ survey data allow depicting a clearer picture of the history of this stock. Indeed, for the horse mackerel species, CMSY or SPiCT results are the preferred models, since for these species landings are not negligible. Notwithstanding, age-structured assessments remain the most powerful approach for evaluating the status of resources, but SPMs have proved to be a powerful tool in a data-limited context
Greenlight laserâą photovaporization versus transurethral resection of the prostate: A systematic review and meta-analysis
none9GreenLight laserâą photovaporization of the prostate (GLL-PVP) has become a valid alternative to traditional transurethral resection of the prostate (TURP) in men requiring surgery for benign prostatic hyperplasia. We aimed to review systematically the safety and efficacy of studies comparing GLL PVP and TURP in the medium-term. A comprehensive literature search was performed. Twelve studies were identified for meta-analysis. Meta-analyses showed a longer postoperative catheterization time (risk ratio (RR): 1.12, 95% CI:1.09â1.14, p<0.00001) and length of stay (RR: 1.16, 95% CI:1.12â1.19, p<0.00001) in the TURP group; higher risk of transfusion in the TURP group (RR: 6.51, 95% CI: 2,90â14,64 p<0.00001); no difference in the risk of urinary tract infections (RR: 0.83, 95% CI: 0.58â1.18, p=0.30) and transient re-catheterization (RR: 1.11, 95% CI: 0.76â1.60, p=0.60). Regarding reoperation rate, no difference was found in term of postoperative urethral stricture (RR: 1.13, 95% CI: 0.73â1.75, p=0.59) and bladder neck contracture (RR: 0.66, 95% CI: 0.31â1.40, p=0.28). A significantly higher incidence in reoperation for persistent/regrowth adenoma was present in the GLLL-PVP (RR: 0.64, 95% CI: 0.41â0.99, p=0.05). Data at 2-year follow-up showed significant better post-voiding residual (PVR) (MD:-1.42, 95% CI:-2.01,-0.82, p<0.00001) and International Prostate Symptom Score (IPSS) (MD:-0.35, 95% CI:-0.50,-0.20, p<0.00001) after TURP. No difference was found in the mean PVR at 2 years after TURP, in the mean maximum flow rate (Qmax) (MD: 0.30, 95% CI:-0.02â0.61, p=0.06) and quality of life QoL score (MD: 0.05, 95% CI:-0.02â0.42, p=0.13). At 5-year follow-up, data showed better IPSS (MD:-1.70, 95% CI:-2.45,-0.95, p<0.00001), QoL scores (MD:-0.35, 95% CI:-0.69,-0.02, p=0.04) and Qmax (MD: 3.29, 95% CI: 0.19â6.38, p=0.04) after TURP. Data of PVR showed no significant difference (MD:-11.54, 95% CI:-29.55â6.46, p=0.21). In conclusion, our analysis shows that GLL-PVP is a safer and more efficacious procedure than standard TURP in the early and medium-term. However, in the long term period GLL-PVP showed a higher incidence of reoperation rate due to incomplete vaporization/regrowth of prostatic adenoma.openCastellani D.; Pirola G.M.; Rubilotta E.; Gubbiotti M.; Scarcella S.; Maggi M.; Gauhar V.; Teoh J.Y.-C.; Galosi A.B.Castellani, D.; Pirola, G. M.; Rubilotta, E.; Gubbiotti, M.; Scarcella, S.; Maggi, M.; Gauhar, V.; Teoh, J. Y. -C.; Galosi, A. B
Formalin-fixed and paraffin-embedded samples for next generation sequencing: Problems and solutions
Over the years, increasing information has been asked of the pathologist: we have moved from a purely morphological diagnosis to biomolecular and genetic studies, which have made it possible to implement the use of molecular targeted therapies, such as anti-epidermal growth factor receptor (EGFR) molecules in EGFR-mutated lung cancer, for example. Today, next generation sequencing (NGS) has changed the approach to neoplasms, to the extent that, in a short time, it has gained a place of absolute importance and diagnostic, prognostic and therapeutic utility. In this scenario, formaldehyde-fixed and paraffin-embedded (FFPE) biological tissue samples are a source of clinical and molecular information. However, problems can arise in the genetic material (DNA and RNA) for use in NGS due to fixation, and work is being devoted to possible strategies to reduce its effects. In this paper, we discuss the applications of FFPE tissue samples in the execution of NGS, we focus on the problems arising with the use of this type of material for nucleic acid extraction and, finally, we consider the most useful strategies to prevent and reduce single nucleotide polymorphisms (SNV) and other fixation artifacts
Strongly structured populations and reproductive habitat fragmentation increase the vulnerability of the Mediterranean starry ray Raja asterias (Elasmobranchii, Rajidae)
The Mediterranean starry ray (Raja asterias) populations within the Mediterranean Sea are susceptible to high rates of bycatch in the multispecies trawl fisheries. Understanding its population structure and identifying critical habitats are crucial for assessing species vulnerability and setting the groundwork for specific management measures to prevent population decline. To assess the population structure of R. asterias in the Mediterranean, the genetic variation in nine population samples at one mitochondrial marker and eight nuclear microsatellite loci was analysed. Moreover, 172 egg cases collected in the Strait of Sicily were identified at species level using integrated molecular and morphological approaches. Genetic analyses revealed that the Mediterranean starry ray comprises three distinct units inhabiting the western, the central-western, and the central-eastern areas of the Mediterranean. An admixture zone occurs in the Strait of Sicily and the Ionian Sea, where individuals of the central-western and central-eastern population units intermingle. The joint morphometricâgenetic analyses of rajid egg cases confirmed the presence of more than one species in the admixture area, with a predominance of egg cases laid by R. asterias. DNA barcoding revealed that egg cases and embryos of R. asterias shared several haplotypes with adult individuals from the central-western and central-eastern Mediterranean Sea, revealing that females of both populations laid numerous eggs in this area. According to these findings, detailed taxonomic determination of egg cases, when combined with seasonal migration studies, could improve the capability to identify important spawning or nursery areas for the Mediterranean starry ray, particularly in those admixture zones relevant to maintaining genetic diversity. Finally, these new insights should be considered to update the Action Plan for the Conservation of Cartilaginous Fishes in the Mediterranean Sea with effective measures to reduce the impact of skate bycatch in trawling and safeguard egg cases in nursery areas
Risk factors for bronchiolitis hospitalization during the first year of life in a multicenter Italian birth cohort
BACKGROUND: Respiratory Syncytial Virus (RSV) is one of the main causes of respiratory infections during the first year of life. Very premature infants may contract more severe diseases and 'late preterm infants' may also be more susceptible to the infection. The aim of this study is to evaluate the risk factors for hospitalization during the first year of life in children born at different gestational ages in Italy. METHODS: A cohort of 33-34 weeks gestational age (wGA) newborns matched by sex and age with two cohort of newborns born at 35-37 wGA andâ>â37 wGA were enrolled in this study for a three-year period (2009-2012). Hospitalization for bronchiolitis (ICD-9 code 466.1) during the first year of life was assessed through phone interview at the end of the RSV season (November-March) and at the completion of the first year of life. RESULTS: The study enrolled 2314 newborns, of which 2210 (95.5 %) had a one year follow-up and were included in the analysis; 120 (5.4 %) were hospitalized during the first year of life for bronchiolitis. Children born at 33-34 wGA had a higher hospitalization rate compared to the two other groups. The multivariate analysis carried out on the entire population associated the following factors with higher rates for bronchiolitis hospitalization: male gender; prenatal treatment with corticosteroids; prenatal exposure to maternal smoking; singleton delivery; respiratory diseases in neonatal period; surfactant therapy; lack of breastfeeding; siblings <10 years old; living in crowded conditions and/or in unhealthy households and early exposure to the epidemic RSV season. When analysis was restricted to preterms born at 33-34 wGA the following variables were associated to higher rates of bronchiolitis hospitalization: male gender, prenatal exposure to maternal smoking, neonatal surfactant therapy, having siblings <10 years old, living in crowded conditions and being exposed to epidemic season during the first three months of life. CONCLUSION: Our study identified some prenatal, perinatal and postnatal conditions proving to be relevant and independent risk factors for hospitalization for bronchiolitis during the first year of life. The combination of these factors may lead to consider palivizumab prophylaxis in Italy
Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC
The uncertainty on the calorimeter energy response to jets of particles is
derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the
calorimeter response to single isolated charged hadrons is measured and
compared to the Monte Carlo simulation using proton-proton collisions at
centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009
and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter
response to specific types of particles (positively and negatively charged
pions, protons, and anti-protons) is measured and compared to the Monte Carlo
predictions. Finally, the jet energy scale uncertainty is determined by
propagating the response uncertainty for single charged and neutral particles
to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3%
for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table,
submitted to European Physical Journal
Measurement of Ï c1 and Ï c2 production with sâ = 7 TeV pp collisions at ATLAS
The prompt and non-prompt production cross-sections for the Ï c1 and Ï c2 charmonium states are measured in pp collisions at sâ = 7 TeV with the ATLAS detector at the LHC using 4.5 fbâ1 of integrated luminosity. The Ï c states are reconstructed through the radiative decay Ï c â J/ÏÎł (with J/Ï â ÎŒ + ÎŒ â) where photons are reconstructed from Îł â e + e â conversions. The production rate of the Ï c2 state relative to the Ï c1 state is measured for prompt and non-prompt Ï c as a function of J/Ï transverse momentum. The prompt Ï c cross-sections are combined with existing measurements of prompt J/Ï production to derive the fraction of prompt J/Ï produced in feed-down from Ï c decays. The fractions of Ï c1 and Ï c2 produced in b-hadron decays are also measured
Measurement of the flavour composition of dijet events in pp collisions at root s=7 TeV with the ATLAS detector
This paper describes a measurement of the flavour composition of dijet events produced in pp collisions at √s=7 TeV using the ATLAS detector. The measurement uses the full 2010 data sample, corresponding to an integrated luminosity of 39Â pbâ1. Six possible combinations of light, charm and bottom jets are identified in the dijet events, where the jet flavour is defined by the presence of bottom, charm or solely light flavour hadrons in the jet. Kinematic variables, based on the properties of displaced decay vertices and optimised for jet flavour identification, are used in a multidimensional template fit to measure the fractions of these dijet flavour states as functions of the leading jet transverse momentum in the range 40Â GeV to 500Â GeV and jet rapidity |y|<2.1. The fit results agree with the predictions of leading- and next-to-leading-order calculations, with the exception of the dijet fraction composed of bottom and light flavour jets, which is underestimated by all models at large transverse jet momenta. The ability to identify jets containing two b-hadrons, originating from e.g. gluon splitting, is demonstrated. The difference between bottom jet production rates in leading and subleading jets is consistent with the next-to-leading-order predictions
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