Full Information Estimations of a System of Simultaneous Equations with Error Component Structure

In this paper we develop full information methods for estimating the parameters of a system of simultaneous equations with error component structure and establish relationships between the various structural estimator

The Polarised Valence Quark Distribution from semi-inclusive DIS

The semi-inclusive difference asymmetry A^{h^{+}-h^{-}} for hadrons of opposite charge has been measured by the COMPASS experiment at CERN. The data were collected in the years 2002-2004 using a 160 GeV polarised muon beam scattered off a large polarised ^6LiD target and cover the range 0.006 < x < 0.7 and 1 < Q^2 < 100 (GeV/c)^2. In leading order QCD (LO) the asymmetry A_d^{h^{+}-h^{-}} measures the valence quark polarisation and provides an evaluation of the first moment of Delta u_v + Delta d_v which is found to be equal to 0.40 +- 0.07 (stat.) +- 0.05 (syst.) over the measured range of x at Q^2 = 10 (GeV/c)^2. When combined with the first moment of g_1^d previously measured on the same data, this result favours a non-symmetric polarisation of light quarks Delta u-bar = - Delta d-bar at a confidence level of two standard deviations, in contrast to the often assumed symmetric scenario Delta u-bar = Delta d-bar = Delta s-bar = Delta s.Comment: 7 pages, 3 figures, COMPASS, revised: details added, author list update

Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR

Simulation results for future measurements of electromagnetic proton form factors at \PANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel $\bar p p \to e^+ e^-$ is studied on the basis of two different but consistent procedures. The suppression of the main background channel, $\textit{i.e.}$ $\bar p p \to \pi^+ \pi^-$, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance

Multicenter European Prevalence Study of Neurocognitive Impairment and Associated Factors in HIV Positive Patients

We conducted a cross-sectional study in 448 HIV positive patients attending five European outpatient clinics to determine prevalence of and factors associated with neurocognitive impairment (NCI) using computerized and pen-and-paper neuropsychological tests. NCI was defined as a normalized Z score ≤-1 in at least 2 out of 5 cognitive domains. Participants' mean age was 45.8 years; 84% male; 87% white; 56% university educated; median CD4 count 550 cells/mm(3); 89% on antiretroviral therapy. 156 (35%) participants had NCI, among whom 26 (17%; 5.8% overall) reported a decline in activities of daily living. Prevalence of NCI was lower in those always able to afford basic needs (adjusted prevalence ratio [aPR] 0.71, 95% confidence interval [CI] 0.54-0.94) or with a university education (aPR 0.72, 95% CI 0.54-0.97) and higher in those with severe depressive symptoms (aPR 1.53, 95% CI 1.09-2.14) or a significant comorbid condition (aPR 1.40, 95% CI 1.03-1.90)

MORFEO enters final design phase

MORFEO (Multi-conjugate adaptive Optics Relay For ELT Observations, formerly MAORY), the MCAO system for the ELT, will provide diffraction-limited optical quality to the large field camera MICADO. MORFEO has officially passed the Preliminary Design Review and it is entering the final design phase. We present the current status of the project, with a focus on the adaptive optics system aspects and expected milestones during the next project phase

Clinical Features, Cardiovascular Risk Profile, and Therapeutic Trajectories of Patients with Type 2 Diabetes Candidate for Oral Semaglutide Therapy in the Italian Specialist Care

Introduction: This study aimed to address therapeutic inertia in the management of type 2 diabetes (T2D) by investigating the potential of early treatment with oral semaglutide. Methods: A cross-sectional survey was conducted between October 2021 and April 2022 among specialists treating individuals with T2D. A scientific committee designed a data collection form covering demographics, cardiovascular risk, glucose control metrics, ongoing therapies, and physician judgments on treatment appropriateness. Participants completed anonymous patient questionnaires reflecting routine clinical encounters. The preferred therapeutic regimen for each patient was also identified. Results: The analysis was conducted on 4449 patients initiating oral semaglutide. The population had a relatively short disease duration (42%  60% of patients, and more often than sitagliptin or empagliflozin. Conclusion: The study supports the potential of early implementation of oral semaglutide as a strategy to overcome therapeutic inertia and enhance T2D management

Study of doubly strange systems using stored antiprotons

Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the P‾ANDA experiment at FAIR. For the first time, high resolution γ-spectroscopy of doubly strange ΛΛ-hypernuclei will be performed, thus complementing measurements of ground state decays of ΛΛ-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Ξ−-atoms will be feasible and even the production of Ω−-atoms will be within reach. The latter might open the door to the |S|=3 world in strangeness nuclear physics, by the study of the hadronic Ω−-nucleus interaction. For the first time it will be possible to study the behavior of Ξ‾+ in nuclear systems under well controlled conditions

Modèles de régression avec variables muettes explicatives

Dans cette note nous considérons des modèles de régression dans lesquels on trouve, parmi les variables explicatives, des variables qualitatives.Le recours à des variables qualitatives explicatives est très fréquent dans les études économiques, comme en sociologie et dans d'autres disciplines,d'où l'importance d'une analyse systématique, sous l'angle méthodologique etopérationnel, du problème de l'estimation d'une régression en présence devariables qualitatives explicatives.Dans le premier paragraphe, nous étudions le modèle de régression classique avec une seule variable muette à plusieurs attributs. On y verra quel'estimation du modèle peut se faire à l'aide d'une transformation très simpledont l'interprétation est fort intéressante. L'extension au cas de plusieursvariables muettes fait l'objet du deuxième paragraphe. On constatera dans ceparagraphe que la simplicité de la solution est perdue, lorsque l'on envisagedes variables muettes multiples. Toutefois, un cas important de modèles àvariables muettes multiples, le modèle à effets individuels et temporels,présente une solution facile et élégante. Ce modèle est discuté au paragraphe 3. Y-a-t-il d'autres cas de solution facile pour des modèles à variables muettes multiples? C'est la question que nous abordons dans le paragraphe 4, où une condition nécessaire et suffisante est donnée. Enfin, dans le dernier paragraphe, le problème des variables muettes est étudié dans le contexte de la régression généralisée, avec une application au modèle "seemingly unrelated regressions" de ZELLNER

Determinant and inverse of a sum of matrices with applications in economics and statistics

In this note we present some useful tools concerning the determinant and the inverse of the sum of two matrices. Some of the results shown here are found in the statistical and econometric literature, but often without proof and without a clear statement of the conditions under which they hold. Some other results, however, are believed to be original. A number of applications in the fields of economics and statistics are given