label free discrimination of cells undergoing apoptosis by hyperspectral confocual reflectance imaging

Among the optical techniques used for exploring the properties of cells and tissues, those based on hyperspectral label-free analysis are particularly interesting due to their non-invasive character and their ability to fast collect a huge number of information on the different sample constituents and their spatial distribution. Here we present results obtained with a novel hyperspectral reflectance confocal microscope of label-free discrimination of cells undergoing apoptosis. Our data, analyzed by means of a powerful statistical method, enable to obtain information on the biological status at a single cell level through the local measurement of reflectivity. Furthermore, an optical model of the local dielectric response gives an additional insight of the parameters linking the optical responsivity to the biological status

Low energy high angular resolution neutral atom detection by means of micro-shuttering techniques: the BepiColombo SERENA/ELENA sensor

The neutral sensor ELENA (Emitted Low-Energy Neutral Atoms) for the ESA cornerstone BepiColombo mission to Mercury (in the SERENA instrument package) is a new kind of low energetic neutral atoms instrument, mostly devoted to sputtering emission from planetary surfaces, from E ~20 eV up to E~5 keV, within 1-D (2x76 deg). ELENA is a Time-of-Flight (TOF) system, based on oscillating shutter (operated at frequencies up to a 100 kHz) and mechanical gratings: the incoming neutral particles directly impinge upon the entrance with a definite timing (START) and arrive to a STOP detector after a flight path. After a brief dissertation on the achievable scientific objectives, this paper describes the instrument, with the new design techniques approached for the neutral particles identification and the nano-techniques used for designing and manufacturing the nano-structure shuttering core of the ELENA sensor. The expected count-rates, based on the Hermean environment features, are shortly presented and discussed. Such design technologies could be fruitfully exported to different applications for planetary exploration.Comment: 11 page

Label-free discrimination of cells undergoing apoptosis by hyperspectral confocual reflectance imaging

Among the optical techniques used for exploring the properties of cells and tissues, those based on hyperspectral label-free analysis are particularly interesting due to their non-invasive character and their ability to fast collect a huge number of information on the different sample constituents and their spatial distribution. Here we present results obtained with a novel hyperspectral reflectance confocal microscope of label-free discrimination of cells undergoing apoptosis. Our data, analyzed by means of a powerful statistical method, enable to obtain information on the biological status at a single cell level through the local measurement of reflectivity. Furthermore, an optical model of the local dielectric response gives an additional insight of the parameters linking the optical responsivity to the biological status

The Helium and Carbon Isotope Characteristics of the Andean Convergent Margin

Subduction zones represent the interface between Earth’s interior (crust and mantle) and exterior (atmosphere and oceans), where carbon and other volatile elements are actively cycled between Earth reservoirs by plate tectonics. Helium is a sensitive tracer of volatile sources and can be used to deconvolute mantle and crustal sources in arcs; however it is not thought to be recycled into the mantle by subduction processes. In contrast, carbon is readily recycled, mostly in the form of carbon-rich sediments, and can thus be used to understand volatile delivery via subduction. Further, carbon is chemically-reactive and isotope fractionation can be used to determine the main processes controlling volatile movements within arc systems. Here, we report helium isotope and abundance data for 42 deeply-sourced fluid and gas samples from the Central Volcanic Zone (CVZ) and Southern Volcanic Zone (SVZ) of the Andean Convergent Margin (ACM). Data are used to assess the influence of subduction parameters (e.g., crustal thickness, subduction inputs, and convergence rate) on the composition of volatiles in surface volcanic fluid and gas emissions. He isotopes from the CVZ backarc range from 0.1 to 2.6 RA (n = 23), with the highest values in the Puna and the lowest in the Sub-Andean foreland fold-and-thrust belt. Atmosphere-corrected He isotopes from the SVZ range from 0.7 to 5.0 RA (n = 19). Taken together, these data reveal a clear southeastward increase in 3He/4He, with the highest values (in the SVZ) falling below the nominal range associated with pure upper mantle helium (8 ± 1 RA), approaching the mean He isotope value for arc gases of (5.4 ± 1.9 RA). Notably, the lowest values are found in the CVZ, suggesting more significant crustal inputs (i.e., assimilation of 4He) to the helium budget. The crustal thickness in the CVZ (up to 70 km) is significantly larger than in the SVZ, where it is just ∼40 km. We suggest that crustal thickness exerts a primary control on the extent of fluid-crust interaction, as helium and other volatiles rise through the upper plate in the ACM. We also report carbon isotopes from (n = 11) sites in the CVZ, where δ13C varies between −15.3‰ and −1.2‰ [vs. Vienna Pee Dee Belemnite (VPDB)] and CO2/3He values that vary by over two orders of magnitude (6.9 × 108–1.7 × 1011). In the SVZ, carbon isotope ratios are also reported from (n = 13) sites and vary between −17.2‰ and −4.1‰. CO2/3He values vary by over four orders of magnitude (4.7 × 107–1.7 × 1012). Low δ13C and CO2/3He values are consistent with CO2 removal (e.g., calcite precipitation and gas dissolution) in shallow hydrothermal systems. Carbon isotope fractionation modeling suggests that calcite precipitation occurs at temperatures coincident with the upper temperature limit for life (122°C), suggesting that biology may play a role in C-He systematics of arc-related volcanic fluid and gas emissions.Fil: Barry, P. H.. Woods Hole Oceanographic Institution; Estados UnidosFil: De Moor, J. M.. University of New Mexico; Estados Unidos. UNIVERSIDAD NACIONAL DE COSTA RICA (UNA);Fil: Chiodi, Agostina Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Aguilera, F.. Universidad Católica del Norte; ChileFil: Hudak, M. R.. Woods Hole Oceanographic Institution; Estados UnidosFil: Bekaert, D. V.. Woods Hole Oceanographic Institution; Estados UnidosFil: Turner, S. J.. University of Massachussets; Estados UnidosFil: Curtice, J.. Woods Hole Oceanographic Institution; Estados UnidosFil: Seltzer, A. M.. Woods Hole Oceanographic Institution; Estados UnidosFil: Jessen, G. L.. Universidad Austral de Chile; ChileFil: Osses, E.. Universidad Austral de Chile; ChileFil: Blamey, J. M.. Universidad de Santiago de Chile; ChileFil: Amenábar, M. J.. Universidad de Santiago de Chile; ChileFil: Selci, M.. University Of Naples Federico Ii; ItaliaFil: Cascone, M.. University Of Naples Federico Ii; ItaliaFil: Bastianoni, A.. University Of Naples Federico Ii; ItaliaFil: Nakagawa, M.. Tokyo Institute Of Technology; JapónFil: Filipovich, Ruben Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Bustos, Emilce. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Schrenk, M. O.. Michigan State University; Estados UnidosFil: Buongiorno, J.. Maryville College; Estados UnidosFil: Ramírez, C. J.. Servicio Geológico Ambiental (segeoam); Costa RicaFil: Rogers, T. J.. University of Tennessee; Estados UnidosFil: Lloyd, K. G.. University of Tennessee; Estados UnidosFil: Giovannelli, D.. Institute Of Marine Biological Resources And Biotechno; Itali

Correction to: SERENA: Particle Instrument Suite for Determining the Sun-Mercury Interaction from BepiColombo

International audienc

SERENA:Particle Instrument Suite for Determining the Sun-Mercury Interaction from BepiColombo

International audienceThe ESA-JAXA BepiColombo mission to Mercury will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric particle dynamics at Mercury as well as their interactions with solar wind, solar radiation, and interplanetary dust. The particle instrument suite SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) is flying in space on-board the BepiColombo Mercury Planetary Orbiter (MPO) and is the only instrument for ion and neutral particle detection aboard the MPO. It comprises four independent sensors: ELENA for neutral particle flow detection, Strofio for neutral gas detection, PICAM for planetary ions observations, and MIPA, mostly for solar wind ion measurements. SERENA is managed by a System Control Unit located inside the ELENA box. In the present paper the scientific goals of this suite are described, and then the four units are detailed, as well as their major features and calibration results. Finally, the SERENA operational activities are shown during the orbital path around Mercury, with also some reference to the activities planned during the long cruise phase

Dielectric properties of the Si(111)2×1 surface: Optical constants and the energy-loss spectrum

We present a method of computation of the optical constants of the surface layer of a solid, starting from a differential reflectivity spectrum. The differential reflectivity was obtained by comparing the overall reflectivity of the same sample in the case of a clean and oxidized surface. The method assumes sharp interfaces at the vacuum surface and at the surface bulk side. The physical properties of the bulk and of the surface layer are described by an energy-dependent dielectric constant. This method is applied to the Si(111)2×1 surface. The surface optical constants are derived in the (0.3-4.0)-eV range. With the use of the same model and the calculated optical constants, the electron-energy-loss spectrum of the Si(111)2×1 surface has been calculated. The agreement with the experiment is good. This is assumed as a proof of the reliability of the optical constants. In addition the comparison of the calculated energy-loss spectrum and the experiment allows the explanation of the apparent disagreement between optical and energy-loss experimental data in the near-infrared range. We demonstrate the different nature between the energy-loss peak and the optical one, the first due to the excitation of the two surface interface modes of the Si(111)2×1 surface layer and the second to an interband transition

ELENA estimated countrates

Here we calculate the expected countrates and ToF distribution for the ELENA instrument. ELENA (Emitted Low-Energy Neutral Atoms) is a neutral sensor, part of the SERENA instrument package, for the ESA cornerstone BepiColombo mission to Mercury; it is a new kind of low energetic neutral atoms instrument. It is designed to measure the sputtering emission from planetary surface in the energy range from E ~50eV up to E~5 keV. ELENA is a Time-of-Flight (ToF) sensor, based on oscillating shutter (operated at frequencies up to a 100 kHz) and mechanical gratings. The incoming neutral particles directly impinge on the entrance with a definite timing (START) and arrive to a STOP detector at the end of a Time-of-Flight (ToF) chamber. This paper describes both the analytical and the numerical estimation of the expected countrates for the ELENA sensor. We consider ion sputtering, backscattering and charge-exchange as possible neutral sources. The instrument noise on the stop MCP is also considered

ELENA geometrical factor estimation

Here we calculate the geometrical factor for the ELENA instrument. ELENA (Emitted Low-Energy Neutral Atoms) is a neutral sensor, part of the SERENA instrument package, for the ESA cornerstone BepiColombo mission to Mercury; it is a new kind of low energetic neutral atoms instrument. It is designed to measure the sputtering emission from planetary surface in the energy range from E ~50eV up to E~5 keV. The instrument FoV is 4.5° by 76°, with nominal resolution of 4.5° by 2°, and nadir pointing. ELENA is a Time-of-Flight (ToF) sensor, based on oscillating shutter (operated at frequencies up to a 100 kHz) and mechanical gratings. The incoming neutral particles directly impinge on the entrance with a definite timing (START) and arrive to a STOP detector at the end of a Time-of-Flight (ToF) chamber. This paper describes both the analytical and the numerical estimation of the geometrical factor for the ELENA sensor. We obtain a geometrical factor of 1.5 10-3 cm2 sr, an angular resolution of 6.5° and a time resolution of 1.5 μs

Si(111) and Si(100) surfaces observed in air by scanning tunneling microscopy

Si(111) and Si(100) surfaces have been observed by an air-operating scanning tunneling microscope (STM). On the cleaved Si(111) surface STM topographic images show predominantly [211BAR]-oriented monatomic steps. The distribution of the width of the terraces is centered around 4 nm. Si(100) surfaces have been hydrogen-terminated by a treatment with fluoridic acid (HF). The surface appears in the topographic STM images to be quite stable and smooth with presumably no oxide