The Radiation Assessment Detector (RAD) on the Mars Science Laboratory (MSL) is an energetic particle detector designed to measure a broad spectrum of energetic particle radiation. It will make the ...first-ever direct radiation measurements on the surface of Mars, detecting galactic cosmic rays, solar energetic particles, secondary neutrons, and other secondary particles created both in the atmosphere and in the Martian regolith. The radiation environment on Mars, both past and present, may have implications for habitability and the ability to sustain life. Radiation exposure is also a major concern for future human missions. The RAD instrument combines charged- and neutral-particle detection capability over a wide dynamic range in a compact, low-mass, low-power instrument. These capabilities are required in order to measure all the important components of the radiation environment.
RAD consists of the RAD Sensor Head (RSH) and the RAD Electronics Box (REB) integrated together in a small, compact volume. The RSH contains a solid-state detector telescope with three silicon PIN diodes for charged particle detection, a thallium doped Cesium Iodide scintillator, plastic scintillators for neutron detection and anti-coincidence shielding, and the front-end electronics. The REB contains three circuit boards, one with a novel mixed-signal ASIC for processing analog signals and an associated control FPGA, another with a second FPGA to communicate with the rover and perform onboard analysis of science data, and a third board with power supplies and power cycling or “sleep”-control electronics. The latter enables autonomous operation, independent of commands from the rover. RAD is a highly capable and highly configurable instrument that paves the way for future compact energetic particle detectors in space.
•This review supports a non-inferiority of vegetarian plus creatine and ovolactovegetarian diets compared omnivorous diet when both have adequate supply of nutrients.•In randomized clinical trials ...testing creatine supplementation for mixed and vegetarian diets, different than expected, both had similar benefits from supplementation, even though the vegetarians possibly had a previous muscle creatine deficit.•There is a significant lack of studies with women in this area.
The aim of this systematic review is to analyze the scientific evidence in relation to neuromuscular adaptations to physical exercise in vegetarians versus omnivores.
A thorough literature search of randomized clinical trials was conducted in PubMed, Embase, CENTRAL (Cochrane), CINAHL, SPORTDiscus, and Web of Science without limitation of the starting date until June of 2021. Trials were eligible for inclusion if they measured the effect of diet (vegetarian or vegan versus omnivorous) of physical activity practitioners on neuromuscular adaptations, such as strength, power, endurance, and muscle hypertrophy.
Eleven studies were selected, most performed with males. The intervention period ranged from one 1 to 12 weeks, and four studies supplement creatine. No statistically significant difference was observed for most parameters, only one study found difference in the strength where it was significantly higher for the vegetarian diet group. Of the studies that had creatine supplementation in one, the peak power output was greater for the mixed diet than for vegetarians, and in the other, vegetarians had total work performance greater than omnivores.
Vegetarian plus creatine and ovolactovegetarian diets seem to have no inferiority compared to the omnivorous diet in relation to neuromuscular adaptations to exercise, but caution still required for other vegetarian diets which that may not provide adequate amounts of protein and micronutrients.
L’objectif de cette revue systématique est d’analyser les preuves scientifiques relatives aux adaptations neuromusculaires à l’exercice physique chez les végétariens par rapport aux omnivores.
Une recherche documentaire approfondie des essais cliniques randomisés a été menée dans PubMed, Embase, CENTRAL (Cochrane), CINAHL, SPORTDiscus et Web of Science sans limitation de date de début jusqu’en juin 2021. Les essais étaient éligibles pour l’inclusion s’ils mesuraient l’effet du régime alimentaire (végétarien ou végétalien versus omnivore) des pratiquants d’activité physique sur les adaptations neuromusculaires, telles que la force, la puissance, l’endurance et l’hypertrophie musculaire.
Onze études ont été sélectionnées, la plupart réalisées avec des hommes. La période d’intervention variait de 1 à 12 semaines, et quatre études utilisaient une supplémentation en créatine. Aucune différence statistiquement significative n’a été observée pour la plupart des paramètres, une seule étude a trouvé une différence de force laquelle était significativement plus élevée pour le groupe végétarien. Parmi les études qui incluaient une supplémentation en créatine dans l’une, la puissance de maximale était plus élevée pour le régime mixte que pour les végétariens, et dans l’autre, les végétariens avaient une performance au travail totale supérieure à celle des omnivores.
Les régimes végétariens supplémentés en créatine et ovolactovégétarien ne semblent pas avoir d’infériorité par rapport au régime omnivore en ce qui concerne les adaptations neuromusculaires à l’exercice, mais la prudence reste de mise pour les autres régimes végétariens qui peuvent ne pas fournir des quantités adéquates de protéines et de micronutriments.
The Energetic Particle Detector Rodríguez-Pacheco, J.; Wimmer-Schweingruber, R. F.; Mason, G. M. ...
Astronomy and astrophysics (Berlin),
10/2020, Letnik:
642
Journal Article
Recenzirano
After decades of observations of solar energetic particles from space-based observatories, relevant questions on particle injection, transport, and acceleration remain open. To address these ...scientific topics, accurate measurements of the particle properties in the inner heliosphere are needed. In this paper we describe the Energetic Particle Detector (EPD), an instrument suite that is part of the scientific payload aboard the Solar Orbiter mission. Solar Orbiter will approach the Sun as close as 0.28 au and will provide extra-ecliptic measurements beyond ∼30° heliographic latitude during the later stages of the mission. The EPD will measure electrons, protons, and heavy ions with high temporal resolution over a wide energy range, from suprathermal energies up to several hundreds of megaelectronvolts/nucleons. For this purpose, EPD is composed of four units: the SupraThermal Electrons and Protons (STEP), the Electron Proton Telescope (EPT), the Suprathermal Ion Spectrograph (SIS), and the High-Energy Telescope (HET) plus the Instrument Control Unit that serves as power and data interface with the spacecraft. The low-energy population of electrons and ions will be covered by STEP and EPT, while the high-energy range will be measured by HET. Elemental and isotopic ion composition measurements will be performed by SIS and HET, allowing full particle identification from a few kiloelectronvolts up to several hundreds of megaelectronvolts/nucleons. Angular information will be provided by the separate look directions from different sensor heads, on the ecliptic plane along the Parker spiral magnetic field both forward and backwards, and out of the ecliptic plane observing both northern and southern hemispheres. The unparalleled observations of EPD will provide key insights into long-open and crucial questions about the processes that govern energetic particles in the inner heliosphere.
We show that a spacecraft launched from Earth towards Mars following a Hohmann minimum energy transfer trajectory has a strong tendency to remain well-connected magnetically to Earth, in the early ...phase of the transfer, or to Mars in the late phase, via the Parker spiral magnetic field. On the return trip, the spacecraft would remain reasonably well-connected magnetically first to Mars and later to Earth. Moreover, good magnetic connectivity occurs on all Hohmann transfers between neighboring planets in the inner solar system out to Mars. We call this hitherto unnamed circumstance the Hohmann–Parker effect. We show consequences of the effect by means of simultaneous cosmic radiation proxy observations made near Earth, near Mars, and at the Mars Science Laboratory on the transfer from Earth to Mars in 2011/2012. We support the observations with simulations of the large-scale magnetic field of the inner heliosphere during this period and compare the results with our predictions. The implications of the Hohmann–Parker effect are discussed.
Display omitted
•We analyzed and modeled heliospheric magnetic field during cruise phase of MSL.•Parker field establishes magnetic connection of MSL with Earth, later with Mars.•Effect present on inbound/outbound Hohmann transfers to neighboring planets.•We show the connection effect with simultaneous cosmic ray observations.•Hohmann–Parker effect also measurable with solar wind, solar energetic particles.
Solar Orbiter is a joint ESA-NASA mission planed for launch in October 2018. The science payload includes remote-sensing and in-situ instrumentation designed with the primary goal of understanding ...how the Sun creates and controls the heliosphere. The spacecraft will follow an elliptical orbit around the Sun, with perihelion as close as 0.28 AU. During the late orbit phase the orbital plane will reach inclinations above 30 degrees, allowing direct observations of the solar polar regions. The Energetic Particle Detector (EPD) is an instrument suite consisting of several sensors measuring electrons, protons and ions over a broad energy interval (2 keV to 15 MeV for electrons, 3 keV to 100 MeV for protons and few tens of keV/nuc to 450 MeV/nuc for ions), providing composition, spectra, timing and anisotropy information. We present an overview of Solar Orbiter from the energetic particle perspective, summarizing the capabilities of EPD and the opportunities that these new observations will provide for understanding how energetic particles are accelerated during solar eruptions and how they propagate through the Heliosphere.
Purpose:
A breast dedicated positron emission tomography (PET) scanner has been developed based on monolithic LYSO crystals coupled to position sensitive photomultiplier tubes (PSPMTs). In this ...study, we describe the design of the PET system and report on its performance evaluation.
Methods:
MAMMI is a breast PET scanner based on monolithic LYSO crystals. It consists of 12 compact modules with a transaxial field of view (FOV) of 170 mm in diameter and 40 mm axial FOV that translates to cover up to 170 mm. The patient lies down in a prone position that facilitates maximum breast elongation. Quantitative performance analysis of the calculated method for the attenuation correction specifically developed for MAMMI, and based on PET image segmentation, has also been conducted in this evaluation. In order to fully determine the MAMMI prototype's performance, we have adapted the measurements suggested for National Electrical Manufacturers Association (NEMA) NU 2-2007 and NU 4-2008 protocol tests, as they are defined for whole-body and small animal PET scanners, respectively.
Results:
Spatial resolutions of 1.6, 1.8, and 1.9 mm were measured in the axial, radial, and tangential directions, respectively. A scatter fraction of 20.8% was obtained and the maximum NEC was determined to be 25 kcps at 44 MBq. The average sensitivity of the system was observed to be 1% for an energy window of (250 keV–750 keV) and a maximum absolute sensitivity of 1.8% was measured at the FOV center.
Conclusions:
The overall performance of the MAMMI reported on this evaluation quantifies its ability to produce high quality PET images. Spatial resolution values below 3 mm were measured in most of the FOV. Only the radial component of spatial resolution exceeds the 3 mm at radial positions larger than 60 mm. This study emphasizes the need for standardized testing methodologies for dedicated breast PET systems similar to NEMA standards for whole-body and small animal PET scanners.
A multi-shot target assembly and automatic alignment procedure for laser–plasma proton acceleration at high repetition rate are introduced. The assembly is based on a multi-target rotating wheel ...capable of hosting more than 5000 targets, mounted on a 3D motorized stage to allow rapid replenishment and alignment of the target material between laser irradiations. The automatic alignment procedure consists of a detailed mapping of the impact positions at the target surface prior to the irradiation that ensures stable operation of the target, which alongside the purpose-built design of the target wheel, enables operation at rates up to 10 Hz. Stable and continuous laser-driven proton acceleration at 10 Hz is demonstrated, with observed cut-off energy stability about 15%.
Chang’E 4 is the first mission to the far side of the Moon and consists of a lander, a rover, and a relay spacecraft. Lander and rover were launched at 18:23 UTC on December 7, 2018 and landed in the ...von Kármán crater at 02:26 UTC on January 3, 2019. Here we describe the Lunar Lander Neutron & Dosimetry experiment (LND) which is part of the Chang’E 4 Lander scientific payload. Its chief scientific goal is to obtain first active dosimetric measurements on the surface of the Moon. LND also provides observations of fast neutrons which are a result of the interaction of high-energy particle radiation with the lunar regolith and of their thermalized counterpart, thermal neutrons, which are a sensitive indicator of subsurface water content.
PDF
