Search results for "moon"
showing 10 items of 32 documents
Measurement of the cosmic ray antiproton/proton flux ratio at TeV energies with the ARGO-YBJ detector
2012
Cosmic ray antiprotons provide an important probe to study the cosmic ray propagation in the interstellar space and to investigate the existence of dark matter. Acting the Earth-Moon system as a magnetic spectrometer, paths of primary antiprotons are deflected in the opposite sense with respect to those of the protons in their way to the Earth. This effect allows, in principle, the search for antiparticles in the direction opposite to the observed deficit of cosmic rays due to the Moon (the so-called `Moon shadow'). The ARGO-YBJ experiment, located at the Yangbajing Cosmic Ray Laboratory (Tibet, P.R. China, 4300 m a.s.l., 606 g/cm$^2$), is particularly effective in measuring the cosmic ray …
Calibration of the Lunar Orbital X-ray Fluorescence Imaging Spectrometer (LOXIA) of Chang'E-1 satellite at INAF-OAPA
2007
The Lunar Orbital X-ray Fluorescence Imaging Spectrometer (LOXIA) designed and constructed at the Institute of High Energy Physics of the Chinese Academy of Sciences to perform chemical composition analysis of the Moon surface will operate on-board the Chang'E-1 mission, the first Chinese lunar spacecraft to be launched in 2007. We report the main results of the calibration measurements that we have performed using the X-ray beamline of the XACT facility of INAFOsservatorio Astronomico di Palermo G.S. Vaiana to determine the quantum efficiency of the XRS detector in the soft X-rays as a function of photon energy and angle of incidence.
Observation of the cosmic ray moon shadowing effect with the ARGO-YBJ experiment
2011
Cosmic rays are hampered by the Moon and a deficit in its direction is expected (the so-called Moon shadow). The Moon shadow is an important tool to determine the performance of an air shower array. Indeed, the westward displacement of the shadow center, due to the bending effect of the geomagnetic field on the propagation of cosmic rays, allows the setting of the absolute rigidity scale of the primary particles inducing the showers recorded by the detector. In addition, the shape of the shadow permits to determine the detector point spread function, while the position of the deficit at high energies allows the evaluation of its absolute pointing accuracy. In this paper we present the obser…
The "Honeymoon Phase" in Children with Type 1 Diabetes Mellitus (T1DM): Frequency, Duration and Predictive Factors at Onset
2012
Abstract: Aim of thè study was: to analyze thè epidemiological features of paediatric T1DM at onset and their relation to remission frequency and duration in thè first year of disease, to assess clinical effìcacy of Glucose Evaluation Trial REMission (GETREM) protocol in terms of induction and maintenance of thè "honeymoon phase" and to evaluate Insulin Dose-Adjusted A1C values at onset [IDAA1C = HbAlc% + (Insulin U/Kg/die x 4)] as a predictor of remission. 181 patients less than 15 years of age were admitted at our Department for T1DM onset and were treated according to GETREM protocol in thè years 2008-2011. The following data were recorded at onset: age, sex, modality of onset according …
Bases moleculares de la actividad señalizadora de dUTPasas
2016
Tesis doctoral: 356 páginas
Estudios estructurales y funcionales de dUTPasas, una amplia familia de enzimas metabólicas con funciones reguladoras
2023
El dUTP es el nucleótido no canónico mayoritario en la célula. Su errónea incorporación en el ADN dispara los sistemas de reparación, los cuales pueden causar la muerte celular por una actuación ininterrumpida. Con el objetivo de prevenir esta situación, y conocida la incapacidad de las ADN polimerasas de distinguir entre el dTTP y el dUTP, las células poseen las proteínas dUTPasas (Duts), capaces de degradar este nucleótido no canónico y, en consecuencia, aumentar la ratio dTTP/dUTP en el pool de nucleótidos celular. A parte de la hidrólisis del dUTP, las Duts poseen otras funciones moonlighting, entre las cuales destaca la capacidad de Duts de fagos de Staphylococcus aureus de interaccion…
Two light sensors decode moonlight versus sunlight to adjust a plastic circadian/circalunidian clock to moon phase
2021
AbstractMany species synchronize their physiology and behavior to specific hours. It is commonly assumed that sunlight acts as the main entrainment signal for ~24h clocks. However, the moon provides similarly regular time information, and increasingly studies report correlations between diel behavior and lunidian cycles. Yet, mechanistic insight into the possible influences of the moon on ~24hr timers is scarce.We studiedPlatynereis dumeriliiand uncover that the moon, besides its role in monthly timing, also schedules the exact hour of nocturnal swarming onset to the nights’ darkest times. Moonlight adjusts a plastic clock, exhibiting <24h (moonlit) or >24h (no moon) periodicity. Abun…
On the optimal control of the circular restricted three body problem
2011
The context of this work is space mechanics. More precisely, we aim at computing low thrust transfers in the Earth-Moon system modeled by the circular restricted three-body problem. The goal is to calculate the optimal steering of the spacecraft engine with respect to two optimization criteria: Final time and fuel consumption. The contributions of this thesis are of two kinds. Geometric, first, as we study the controllability of the system together with the geometry of the transfers (structure of the command) by means of geometric control tools. Numerical, then, different homotopic methods being developed. A two-three body continuation is used to compute minimum time trajectories, and then …
Dust environment of an airless object: A phase space study with kinetic models
2016
Abstract The study of dust above the lunar surface is important for both science and technology. Dust particles are electrically charged due to impact of the solar radiation and the solar wind plasma and, therefore, they affect the plasma above the lunar surface. Dust is also a health hazard for crewed missions because micron and sub-micron sized dust particles can be toxic and harmful to the human body. Dust also causes malfunctions in mechanical devices and is therefore a risk for spacecraft and instruments on the lunar surface. Properties of dust particles above the lunar surface are not fully known. However, it can be stated that their large surface area to volume ratio due to their irr…