Acquired tracheoesophageal fistula repair, due to prolonged mechanical ventilation, in patient with double incomplete aortic arch

We report a case of the repair of an acquired benign tracheoesophageal fistula (TEF) after prolonged mechanical invasive ventilation. Patient had an unknown double incomplete aortic arch determining a vascular ring above trachea and esophagus. External tracheobronchial compression, caused by the vascular ring, increasing the internal tracheoesophageal walls pressure determined by endotracheal and nasogastric tubes favored an early TEF development. The fistula was repaired through an unusual left thoracotomy and vascular ring dissection. TEFs are a heterogeneous group of diseases affecting critically ill patients. Operative closure is necessary to avoid further complications related to this condition. Pre-opera-tive study is mandatory to plan an adequate surgical approach

The two Ultraluminous X-ray sources in the galaxy NGC 925

NGC 925 ULX-1 and ULX-2 are two ultraluminous X-ray sources in the galaxy NGC 925, at a distance of 8.5 Mpc. For the first time, we analyzed high quality, simultaneous XMM-Newton and NuSTAR data of both sources. Although at a first glance ULX-1 resembles an intermediate mass black hole candidate (IMBH) because of its high X-ray luminosity ($(2$$-$$4)\times10^{40}$ erg s$^{-1}$) and its spectral/temporal features, a closer inspection shows that its properties are more similar to those of a typical super-Eddington accreting stellar black hole and we classify it as a `broadened disc' ultraluminous X-ray source. Based on the physical interpretation of this spectral state, we suggest that ULX-1 is seen at small inclination angles, possibly through the evacuated cone of a powerful wind originating in the accretion disc. The spectral classification of ULX-2 is less certain, but we disfavour an IMBH accreting at sub-Eddington rates as none of its spectral/temporal properties can be associated to either the soft or hard state of Galactic accreting black hole binaries.Comment: Accepted on MNRAS with very minor comments, 7 pages, 5 figures, 1 tabl

Cirrus clouds in convective outflow during the HIBISCUS campaign

International audienceLight-weight microlidar measurements were taken on-board a stratospheric balloon during the HIBISCUS 2004 campaign, held in Bauru, Brazil (22 S, 49 W). Tropical cirrus observations showed high mesoscale variability in optical and microphysical properties. The cirrus clouds were observed throughout the flight between 12 and 15 km height. It was found that the clouds were composed of different layers, characterized by a marked variability in height, thickness and optical properties. Trajectory analysis and mesoscale transport simulations clearly revealed that the clouds had formed in the outflow of a large and persistent convective region, while the observed optical properties and cloud structure variability could be linked to different residence times of convective-processed air in the upper troposphere. Mesoscale simulations were able to reproduce the supersaturation due to recent outflow, while it was necessary to consider the presence of other formation processes than convective hydration for cirrus forming in aged detrained anvils

QuantEYE: The Quantum Optics Instrument for OWL

QuantEYE is designed to be the highest time-resolution instrument on ESO:s planned Overwhelmingly Large Telescope, devised to explore astrophysical variability on microsecond and nanosecond scales, down to the quantum-optical limit. Expected phenomena include instabilities of photon-gas bubbles in accretion flows, p-mode oscillations in neutron stars, and quantum-optical photon bunching in time. Precise timescales are both variable and unknown, and studies must be of photon-stream statistics, e.g., their power spectra or autocorrelations. Such functions increase with the square of the intensity, implying an enormously increased sensitivity at the largest telescopes. QuantEYE covers the optical, and its design involves an array of photon-counting avalanche-diode detectors, each viewing one segment of the OWL entrance pupil. QuantEYE will work already with a partially filled OWL main mirror, and also without [full] adaptive optics.Comment: 7 pages; Proceedings from meeting 'Instrumentation for Extremely Large Telescopes', held at Ringberg Castle, July 2005 (T.Herbst, ed.

Quality of life and anorectal malformations: a single-center experience

Purpose: The treatment and long term clinical outcomes of anorectal malformations (ARM) in children have always been the focus of pediatric surgeons. This study aimed at reporting our experience as far as long-term follow-up of ARM in children is concern. Methods: We enrolled patients treated between 1999 and 2019, and established selection criteria to choose appropriate subjects. A validated questionnaire was used to determine long-term quality of life outcomes. Results: Out of a total of 48 patients treated within the study period, 28 were enrolled in this study. Among the latter, more than 35% had at least one long-time complication, and more than 90% had a good lifestyle. Urinary and fecal continence was achieved in more than 95% of the patients using medical devices. Conclusion: This study aimed to bring up new concepts; taking into consideration all aspects of life in patients with ARM, from school life to sexuality, while evaluating fecal and urinary continence. This is essential for the improvement of the skills of the different specialists involved in the management of these patients, and for the implementation of strategies that can improve postoperative function. Most especially, it will also help improve communication between doctors to ensure an adequate transition of these children into adult life

Detection of pulsations and a spectral feature in the X-ray emission of the isolated neutron star 1RXS J214303.7+065419/RBS 1774

We report on the results of a deep XMM-Newton observation of RBS 1774, the most recent dim isolated neutron star candidate found in the ROSAT archive data. Spectral and timing analysis of the high-quality PN and MOS data confirm the association of this source with an isolated neutron star. The spectrum is thermal and blackbody-like, and there is evidence at a significance level > 4sigma that the source is an X-ray pulsar, with spin period of 9.437 s. Spectral fitting reveils the presence of an absorption feature at ~0.7 keV, but at this level data do not have enough resolution to allow us to discriminate between an absorption line or an edge. We compare the newly measured properties of RBS 1774 with those of other known dim isolated neutron stars, and discuss possible interpretations for the absorption feature.Comment: 21 pages, 5 figures, ApJ accepte

I sistemi multi-agents e gli algoritmi di consenso

Recently, multi-agent systems have become a central study topic in many different disciplines including biology, engineering, physics, and social science. This has led to the emergence of large and constantly growing interdisciplinary research field, known as network science. The analysis of the mathematical models describing such systems has achieved significant results, but remains mostly an open research field, where many fundamental breakthroughs are expected in the next years. Such analysis is especially motivated by the quest for the development of tools for control and design of such systems. In this paper, we deal with consensus algorithms, an important example of design of multi-agent systems that has been inspired by the dynamics of cooperative systems in natural and social sciences

Discovery of a 0.42-s pulsar in the ultraluminous X-ray source NGC 7793 P13

NGC 7793 P13 is a variable (luminosity range ~100) ultraluminous X-ray source (ULX) proposed to host a stellar-mass black hole of less than 15 M$_{\odot}$ in a binary system with orbital period of 64 d and a 18-23 M$_{\odot}$ B9Ia companion. Within the EXTraS project we discovered pulsations at a period of ~0.42 s in two XMM-Newton observations of NGC 7793 P13, during which the source was detected at $L_{\mathrm{X}}\sim2.1\times10^{39}$ and $5\times10^{39}$ erg s$^{-1}$ (0.3-10 keV band). These findings unambiguously demonstrate that the compact object in NGC 7793 P13 is a neutron star accreting at super-Eddington rates. While standard accretion models face difficulties accounting for the pulsar X-ray luminosity, the presence of a multipolar magnetic field with $B$ ~ few $\times$ 10$^{13}$ G close to the base of the accretion column appears to be in agreement with the properties of the system.Comment: 5 pages, 5 figures, 2 tables; Version accepted for publication in MNRAS Letter

Voxel-based investigations of regional cerebral blood flow abnormalities in Alzheimer's disease using a single-detector SPECT system

PURPOSE: To evaluate the feasibility of using the Statistical Parametric Mapping (SPM) program for an automated, voxel-by-voxel assessment of regional cerebral blood flow (rCBF) deficits in Alzheimer's disease (AD) subjects relative to age-matched controls studied with a conventional, single-detector SPECT system. METHODS: We used a databank of 99mTc-HMPAO images of 19 patients with a diagnosis of probable AD and 15 elderly healthy volunteers; data were acquired using an Orbiter-Siemens single-detector SPECT system. Using SPM, images were transformed spatially, smoothed (12mm), and the data were compared on a voxel-by-voxel basis with t-tests. RESULTS: There were significant rCBF reductions in AD patients relative to controls involving regions predicted a priori to be affected in AD, namely the left temporal and parietal neocortices, and the right posterior cingulate gyrus (pOBJETIVO: Avaliar a viabilidade de emprego do programa Statistical Parametric Mapping (SPM) para investigar de forma automatizada, voxel-a-voxel, a presença de déficits de fluxo sanguíneo cerebral regional (FSCr) em pacientes com doença de Alzheimer (DA) comparados a sujeitos-controle pareados para idade, usando imagens de SPECT adquiridas com um equipamento convencional de detector único. MÉTODOS: Foi utilizado um banco de imagens adquiridas após injeção de 99mTc-HMPAO em 19 pacientes com diagnóstico provável de DA e 15 voluntários idosos saudáveis, usando um equipamento de SPECT Orbiter-Siemens de detector único. Empregando o programa SPM, as imagens foram transformadas espacialmente, suavizadas (12mm FWHM), e comparadas estatisticamente voxel-a-voxel entre os dois grupos, usando o teste de T. RESULTADOS: Foram identificadas reduções significativas de FSCr nos pacientes com DA comparados aos controles em regiões previstas a priori como afetadas por esta forma de demência, quais sejam os neocórtices temporal e parietal em hemisfério esquerdo e o cíngulo posterior direito (p<0,05, corrigido para comparações múltiplas). DISCUSSÃO: A localização dos focos de redução de FSCr em pacientes com DA no nosso estudo é, de forma geral, consistente com os achados de déficits cerebrais detectados em estudos anteriores de neuroimagem funcional na DA realizados com equipamentos de resolução espacial mais alta. Isto sugere o potencial de utilidade do programa SPM para a análise de dados de SPECT adquiridos com equipamentos de detector único, apesar da sensibilidade e resolução espacial limitadas de tais aparelhos

Voxel-based investigations of regional cerebral blood flow abnormalities in Alzheimer's disease using a single-detector SPECT system

PURPOSE: To evaluate the feasibility of using the Statistical Parametric Mapping (SPM) program for an automated, voxel-by-voxel assessment of regional cerebral blood flow (rCBF) deficits in Alzheimer's disease (AD) subjects relative to age-matched controls studied with a conventional, single-detector SPECT system. METHODS: We used a databank of 99mTc-HMPAO images of 19 patients with a diagnosis of probable AD and 15 elderly healthy volunteers; data were acquired using an Orbiter-Siemens single-detector SPECT system. Using SPM, images were transformed spatially, smoothed (12mm), and the data were compared on a voxel-by-voxel basis with t-tests. RESULTS: There were significant rCBF reductions in AD patients relative to controls involving regions predicted a priori to be affected in AD, namely the left temporal and parietal neocortices, and the right posterior cingulate gyrus (pOBJETIVO: Avaliar a viabilidade de emprego do programa Statistical Parametric Mapping (SPM) para investigar de forma automatizada, voxel-a-voxel, a presença de déficits de fluxo sanguíneo cerebral regional (FSCr) em pacientes com doença de Alzheimer (DA) comparados a sujeitos-controle pareados para idade, usando imagens de SPECT adquiridas com um equipamento convencional de detector único. MÉTODOS: Foi utilizado um banco de imagens adquiridas após injeção de 99mTc-HMPAO em 19 pacientes com diagnóstico provável de DA e 15 voluntários idosos saudáveis, usando um equipamento de SPECT Orbiter-Siemens de detector único. Empregando o programa SPM, as imagens foram transformadas espacialmente, suavizadas (12mm FWHM), e comparadas estatisticamente voxel-a-voxel entre os dois grupos, usando o teste de T. RESULTADOS: Foram identificadas reduções significativas de FSCr nos pacientes com DA comparados aos controles em regiões previstas a priori como afetadas por esta forma de demência, quais sejam os neocórtices temporal e parietal em hemisfério esquerdo e o cíngulo posterior direito (