531 research outputs found

    Extracting HI cosmological signal with Generalized Needlet Internal Linear Combination

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    HI intensity mapping is a new observational technique to map fluctuations in the large-scale structure of matter using the 21 cm emission line of atomic hydrogen (HI). Sensitive radio surveys have the potential to detect Baryon Acoustic Oscillations (BAO) at low redshifts (z < 1) in order to constrain the properties of dark energy. Observations of the HI signal will be contaminated by instrumental noise and, more significantly, by astrophysical foregrounds, such as Galactic synchrotron emission, which is at least four orders of magnitude brighter than the HI signal. Foreground cleaning is recognised as one of the key challenges for future radio astronomy surveys. We study the ability of the Generalized Needlet Internal Linear Combination (GNILC) method to subtract radio foregrounds and to recover the cosmological HI signal for a general HI intensity mapping experiment. The GNILC method is a new technique that uses both frequency and spatial information to separate the components of the observed data. Our results show that the method is robust to the complexity of the foregrounds. For simulated radio observations including HI emission, Galactic synchrotron, Galactic free-free, radio sources and 0.05 mK thermal noise, we find that we can reconstruct the HI power spectrum for multipoles 30 < l < 150 with 6% accuracy on 50% of the sky for a redshift z ~ 0.25.Comment: 20 pages, 13 figures. Updated to match version accepted by MNRA

    Assessing the Feasibility of MaaS. A Contribution from Three Italian Case Studies

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    Making all types of public and private transport services available to users through a single and integrated digital platform is the new urban mobility paradigm called Mobility as a Service (MaaS). This scheme allows both a more sustainable urban transportation system and a more effi-cient transport service for users. For MaaS to be successful, its implementation should adapt to the specific features of the location covered by the service. The city maturity level has to be considered in terms of multimodality, infrastructures, regulations, user goals, and user willingness to use and pay for MaaS services. This paper discusses and analyses the results of a survey on MaaS con-ducted in three Italian metropolitan areas: Turin, Rome, and Genoa, which have very different and specific characteristics. The comparative analysis enables the definition of drivers, obstacles, and requisites for MaaS implementation to be successful. When it comes to cities with conservative mobility policies or cities that are new to MaaS experiences, resistance to adoption of the service might occur. The results of the research discussed in this paper can be a useful resource to enable decision makers to develop more effective and efficient transportation policies

    New Approach for Boat Motion Analysis in Rowing

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    In rowing, the study of the movement of the boat and of the rower in the boat is difficult. Indeed, the shell is quite narrow and fragile and it is impossible to use the classical apparatus for physiological and biomechanical analysis. For this reason, the physiological studies of rowers (cardiac and pulmonary parameters) have been more easily realised on specific and non specific ergometers (see Hagerman for an extensive review 1984): it is well known now, that rowers have exceptional aerobic possibilities and also use anaerobiosis for the start and the final part of the race (Hagerman 1984). In contrast, only a few publications deal with the movement of the boat and the rower. The velocity of the boat at different stroke rates (Martin and Bernfield 1980), the angular velocities of various articulations of the rowers (Nelson and Widule 1983) were studied by kinematic analysis. Though this technique is very useful, it does not catch the movements behind the subjects and is of no use to record physiological and mechanical parameters (Ishiko 1967). Some authors used DC recorder placed in a motor boat following the racing shell to record different parameters (Baird and Soroka 1952; Di Prampero 1971; Celentano 1974). But, this technique is not practical because of the need of a second operator to keep the cables out of the water. With the miniaturization, Ishiko proposed and used multichanneltelemetry to record the force of the rower and the acceleration of the boat (Ishiko 1967; Ishiko 1971). Schneider also used the same technique to record the force of the rower in the boat (Schneider 1978). Though this technique is excellent and powerful, it is also very expensive and quite sophisticated. Our goal was thus to take advantage of the miniaturization of the elements and to build and use a recorder and transducers that can be placed into the boat to record the acceleration of the boat and the propulsive force of the rower

    Methods for Multiloop Identification of Visual and Neuromuscular Pilot Responses

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    In this paper, identification methods are proposed to estimate the neuromuscular and visual responses of a multiloop pilot model. A conventional and widely used technique for simultaneous identification of the neuromuscular and visual systems makes use of cross-spectral density estimates. This paper shows that this technique requires a specific noninterference hypothesis, often implicitly assumed, that may be difficult to meet during actual experimental designs. A mathematical justification of the necessity of the noninterference hypothesis is given. Furthermore, two methods are proposed that do not have the same limitations. The first method is based on autoregressive models with exogenous inputs, whereas the second one combines cross-spectral estimators with interpolation in the frequency domain. The two identification methods are validated by offline simulations and contrasted to the classic method. The results reveal that the classic method fails when the noninterference hypothesis is not fulfilled; on the contrary, the two proposed techniques give reliable estimates. Finally, the three identification methods are applied to experimental data from a closed-loop control task with pilots. The two proposed techniques give comparable estimates, different from those obtained by the classic method. The differences match those found with the simulations. Thus, the two identification methods provide a good alternative to the classic method and make it possible to simultaneously estimate human's neuromuscular and visual responses in cases where the classic method fails

    Tris-ureas as transmembrane anion transporters

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    Nine tris-urea receptors (L1–L9) have been synthesised and shown to coordinate to a range of anionic guests both by 1H NMR titration techniques and single crystal X-ray structural analysis. The compounds have been shown to be capable of mediating the exchange of chloride and nitrate and also chloride and bicarbonate across POPC or POPC : cholesterol 7 : 3 vesicle bilayer membranes at low transporter loadings. An interesting dependency of anion transport on the nature of the cation is evidence to suggest that a M+/Cl− cotransport process may also contribute to the release of chloride from the vesicles

    RESECCIÓN HISTEROSCÓPICA DEL SEPTO UTERINO EN MUJERES INFÉRTILES

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    Análisis retrospectivo de 11 pacientes con útero septado sintomático que fueron tratadas con metroplastía histeroscópica en un período de 10 años. Estas pacientes presentaban un total de 16 embarazos, con 14 abortos de primer trimestre y 2 partos pretérmino inmaduros con neomortinatos, sin niños vivos. El propósito de este estudio fue mostrar la eficacia de la histeroscopia quirúrgica en resolver esta patología y mejorar el pronóstico reproductivo. Se intervinieron 7 pacientes con septo parcial y 4 con septo completo. En 8 casos hubo resección del tabique con resectoscopio y en 3 con tijera histeroscópica flexible. Se obtuvo embarazo de término en 6 pacientes (55%) con recién nacidos normales. De las 5 pacientes que no embarazaron, 3 tenían infertilidad por factor tuboperitoneal extenso, una sin relación de pareja y otra sin controles. Se demuestra la utilidad de la resección histeroscópica del útero septado en cuanto al menor tiempo de hospitalización, la baja morbilidad y los buenos resultados reproductivo

    Measuring adolescents' perceptions of parenting style during childhood: psychometric properties of the parenting styles and dimensions questionnaire

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    The paper analyzes the psychometric properties of the G1 version of the Parenting Styles and Dimensions Questionnaire, a self-report instrument designed to investigate how adolescents or adults were parented during childhood. The sample included 1451 Italian adolescents in high school. Three studies tested the scale's structure, invariance, and convergent validity. The first found slightly acceptable fit indexes for a 40-item scale measuring three factors (authoritative, authoritarian, and permissive styles); the factors presented good reliability (ρc .62-.96). Multigroup confirmative analyses found factor loadings invariant in the father version, whereas 12 items resulted not invariant in the mother version (second study). Good convergent validity was found with the Parental Bonding Index and the Parental Monitoring Scale (third study). Discussion of results is provided within the parenting styles literature

    Parasitosis intestinal y estado inmunológico en pacientes adultos con infección por VIH del Centro Médico Naval "Cirujano Mayor Santiago Távara"

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    Objetivo: Describir los tipos parasitosis intestinales y el estado inmunológico en pacientes portadores del virus de la inmunodeficiencia humana (VIH +). Materiales y métodos: Se realizó un estudio descriptivo, comparativo y retrospectivo, a través de la selección de 81 historias clínicas pertenecientes al Servicio de Infectología del Centro Médico Naval "Cirujano Mayor Santiago Távara", con el permiso de las autoridades del centro. Las historias contaban con el único criterio de inclusión considerado en la investigación que fue diagnóstico de infección por VIH. Los datos que se obtuvieron fueron los resultados de examen coproparasitológico y citometría de flujo para linfocitos T CD4, la presencia o ausencia de sintomatología intestinal, y pertenencia al programa de tratamiento antirretroviral de alta actividad (TARGA) o al tratamiento antirretroviral convencional. Resultados: El 37 % presentaron parasitosis intestinal. Se observó con mayor frecuencia a Entamoeba coli (20 %), que es no patógeno para el ser humano. Entre los patógenos hallados se encuentran Isospora belli (15,6 %), Giardia lamblia (15,6 %), Blastocystis hominis (11,2 %) y Cryptosporidium sp. (11,2 %). El 32,1 % de los casos presentaron diarrea, mientras que el 67,9 % fueron asintomáticos. En el grupo de asintomáticos, el promedio de CD4 es de 280 células/μL, mientras en los que tuvieron diarrea fue de 195 células/μL. Conclusiones: Los enteroparásitos Isospora belli, Cyclospora cayetanensis, Blastocystis hominis son hallados con mayor frecuencia en recuentos de CD4 200 células/uL

    Lower grade gliomas: relationships between metabolic and structural imaging with grading and molecular factors

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    Background: Positron emission tomography (PET) is a valuable tool for the characterization of brain tumors in vivo. However, few studies have investigated the correlation between carbon-11-methionine (11C-METH) PET metrics and the clinical, radiological, histological, and molecular features of patients affected by lower grade gliomas (LGGs). The present observational study evaluated the relationships between 11C-METH PET metrics and structural magnetic resonance imaging (MRI) findings with the histomolecular biomarkers in patients with LGGs who were candidates for surgery. Methods: We enrolled 96 patients with pathologically proven LGG (51 men, 45 women; age 44.1 \ub1 13.7 years; 45 with grade II, 51 with grade III), who had been referred from March 2012 to January 2015 for tumor resection and had undergone preoperative 11C-METH PET. The semiquantitative metrics for 11C-METH PET included maximum standardized uptake value (SUVmax), SUV ratio to normal brain, and metabolic tumor burden (MTB). The PET semiquantitative metrics were analyzed and compared with the MRI features, histological diagnosis, isocitrate dehydrogenase-1/2 status, and 1p/19q codeletion. Results: Histological grade was associated with SUVmax (P = 0.002), SUV ratio (P = 0.011), and MTB (P = 0.001), with grade III lesions showing higher values. Among the nonenhancing lesions on MRI, SUVmax (P = 0.001), SUV ratio (P = 0.003) and MTB (P < 0.001) were significantly different statistically for grade II versus grade III. The MRI lesion volume correlated poorly with MTB (r 2 = 0.13). The SUVmax and SUV ratio were greater (P < 0.05) in isocitrate dehydrogenase-1/2 wild-type lesions, and the SUV ratio was associated with the presence of the 1p19q codeletion. Conclusions: The 11C-METH PET metrics correlated significantly with histological grade and the molecular profile. Semiquantitative PET metrics can improve the preoperative evaluation of LGGs and thus support clinical decision-making
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