Trace Element Distribution in Zoned Kyanite of Thassos Island (Greece) Using Combined Spectroscopic Analyses.

Comprehensive mineralogical and petrographic studies require analytical methods capable to report the distribution of major to trace elements within crystals in order to unravel their formation conditions and subsequent evolution. Additionally, the investigation of transition elements (e.g., Ti, V, Cr, Mn, Fe, and Zn) is essential for the comprehension of substitution processes within colored minerals. This study is conducted on a zoned kyanite crystal from a deformed quartz vein found within garnet-kyanite-biotite-hematite-plagioclase±staurolite±sillimanite paragneiss of Thassos Island, Greece. Herein, we show the efficiency of combining conventional, for example, cathodoluminescence, electron probe microanalysis (EPMA), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and new methods, for example, micro-laser-induced breakdown spectroscopy (µLIBS), micro-X-ray fluorescence (µXRF), and Raman spectroscopy, to determine the chemical and crystallographic features of minerals. The simple chemistry of this crystal offers an ideal case to compare and valuate the potential of combined spectroscopy techniques to analyze minerals. We demonstrate that µLIBS and µXRF are perfectly adapted to perform multi-element imaging of major to trace elements down to the ppm level within a pluricentimetric crystal (2.3 x 0.5 cm) prior to quantitative analyses. We also highlight the benefit of cathodoluminescence and Raman mapping in the investigation of crystallographic features within minerals. The multispectroscopic approach enabled us to correlate growth stages of kyanite with the polymetamorphic history of the sample. Our results also highlight the spatial dependence of Ti for the generation of blue zonation by Fe2+-Ti4+ substitutions with Al3+.

On the Ethics of Vaccine Nationalism: The Case for the Fair Priority for Residents Framework.

COVID-19 vaccines are likely to be scarce for years to come. Many countries, from India to the U.K., have demonstrated vaccine nationalism. What are the ethical limits to this vaccine nationalism? Neither extreme nationalism nor extreme cosmopolitanism is ethically justifiable. Instead, we propose the fair priority for residents (FPR) framework, in which governments can retain COVID-19 vaccine doses for their residents only to the extent that they are needed to maintain a noncrisis level of mortality while they are implementing reasonable public health interventions. Practically, a noncrisis level of mortality is that experienced during a bad influenza season, which society considers an acceptable background risk. Governments take action to limit mortality from influenza, but there is no emergency that includes severe lockdowns. This "flu-risk standard" is a nonarbitrary and generally accepted heuristic. Mortality above the flu-risk standard justifies greater governmental interventions, including retaining vaccines for a country's own citizens over global need. The precise level of vaccination needed to meet the flu-risk standard will depend upon empirical factors related to the pandemic. This links the ethical principles to the scientific data emerging from the emergency. Thus, the FPR framework recognizes that governments should prioritize procuring vaccines for their country when doing so is necessary to reduce mortality to noncrisis flu-like levels. But after that, a government is obligated to do its part to share vaccines to reduce risks of mortality for people in other countries. We consider and reject objections to the FPR framework based on a country: (1) having developed a vaccine, (2) raising taxes to pay for vaccine research and purchase, (3) wanting to eliminate economic and social burdens, and (4) being ineffective in combating COVID-19 through public health interventions.

The SuperCam Instrument Suite on the NASA Mars 2020 Rover: Body Unit and Combined System Tests.

The SuperCam instrument suite provides the Mars 2020 rover, Perseverance, with a number of versatile remote-sensing techniques that can be used at long distance as well as within the robotic-arm workspace. These include laser-induced breakdown spectroscopy (LIBS), remote time-resolved Raman and luminescence spectroscopies, and visible and infrared (VISIR; separately referred to as VIS and IR) reflectance spectroscopy. A remote micro-imager (RMI) provides high-resolution color context imaging, and a microphone can be used as a stand-alone tool for environmental studies or to determine physical properties of rocks and soils from shock waves of laser-produced plasmas. SuperCam is built in three parts: The mast unit (MU), consisting of the laser, telescope, RMI, IR spectrometer, and associated electronics, is described in a companion paper. The on-board calibration targets are described in another companion paper. Here we describe SuperCam's body unit (BU) and testing of the integrated instrument. The BU, mounted inside the rover body, receives light from the MU via a 5.8 m optical fiber. The light is split into three wavelength bands by a demultiplexer, and is routed via fiber bundles to three optical spectrometers, two of which (UV and violet; 245-340 and 385-465 nm) are crossed Czerny-Turner reflection spectrometers, nearly identical to their counterparts on ChemCam. The third is a high-efficiency transmission spectrometer containing an optical intensifier capable of gating exposures to 100 ns or longer, with variable delay times relative to the laser pulse. This spectrometer covers 535-853 nm ( 105 - 7070 cm - 1 Raman shift relative to the 532 nm green laser beam) with 12 cm - 1 full-width at half-maximum peak resolution in the Raman fingerprint region. The BU electronics boards interface with the rover and control the instrument, returning data to the rover. Thermal systems maintain a warm temperature during cruise to Mars to avoid contamination on the optics, and cool the detectors during operations on Mars. Results obtained with the integrated instrument demonstrate its capabilities for LIBS, for which a library of 332 standards was developed. Examples of Raman and VISIR spectroscopy are shown, demonstrating clear mineral identification with both techniques. Luminescence spectra demonstrate the utility of having both spectral and temporal dimensions. Finally, RMI and microphone tests on the rover demonstrate the capabilities of these subsystems as well.

Detection of minor compounds in complex mineral samples from millions of spectra: A new data analysis strategy in LIBS imaging.

Today, Laser-Induced Breakdown Spectroscopy (LIBS) imaging is in full change. Indeed, always more stable instrumentations are developed, which significantly increases the signal quality and naturally the analytical potential of the technique for the characterization of complex and heterogeneous samples at the micro-scale level. Obviously, other intrinsic features such as a limit of detection in the order of ppm, a high field of view and high acquisition rate make it one of the most complete chemical imaging techniques to date. It is thus possible in these conditions to acquire several million spectra from one single sample in just hours. Managing big data in LIBS imaging is the challenge ahead. In this paper, we put forward a new spectral analysis strategy, called embedded k-means clustering, for simultaneous detection of major and minor compounds and the generation of associated localization maps. A complex rock section with different phases and traces will be explored to demonstrate the value of this approach.

Integrating Multidisciplinary Results to Produce New Knowledge About the Physician-Patient Relationship: A Methodology Applied to the INTERMEDE Project.

The INTERMEDE Project brought together a number of research teams to study the interaction between a patient and their general practitioner, and how this can produce social inequalities in health. The ultimate objective of the project was to formalize a core of common findings by integrating qualitative and quantitative results. The methodology chosen for the integration was inspired by the Delphi participatory method. It involves several rounds of questions and feedback in writing between all members of project teams, in order to compare contradictory opinions and identify key concepts arising from the project. This interdisciplinary research has provided a more nuanced understanding of the mechanisms underlying physician-patient interaction by revealing the convergences of the various disciplinary approaches.

Clinical use of p-proteasome in discriminating metastatic melanoma patients: comparative study with LDH, MIA and S100B protein.

Plasmatic proteasome (p-proteasome) has recently been described as a new marker for metastatic melanoma. The objective of this study was to compare the diagnostic and prognostic values of p-proteasome with three other melanoma serological markers: S100B protein, melanoma inhibitory activity protein (MIA) and lactate dehydrogenase (LDH) in the plasma of 121 stage I-IV melanoma patients. Laboratory analyses were performed by standardized ELISA (p-proteasome, MIA), immunoluminometric assay (S100B) and colorimetry (LDH). We found that all markers were relevant for discriminating metastatic from nonmetastatic patients but p-proteasome displayed the highest diagnostic accuracy. P-proteasome and S100B were the most sensitive (58.1%) and p-proteasome and MIA the most specific (98.7 and 100%) in detecting metastatic disease. P-proteasome and S100B had the highest area under receiver operating characteristics curve, 0.811 (95% CI: 0.725-0.897) and 0.822 (95% CI: 0.738-0.906), respectively. These two markers were the best in detecting patients with lymph node metastases. S100B, MIA and LDH diagnostic accuracy was increased when these markers were combined with p-proteasome. As shown with univariate analysis, shorter progression-free and overall survival rates were significantly associated with elevated plasma levels of each markers. The multivariate Cox regression analysis identified p-proteasome as the only independent predictor of a poorer progression-free survival (p = 0.030). In conclusion, this comparative study established that p-proteasome quantification in combination with other melanoma biomarkers is an attractive approach for the biological follow-up of melanoma patients.