903 research outputs found
Evolution of the Scientific Instrumentation for <em>In Situ</em> Mars Exploration
Mars has always been a magnet for the human curiosity. The more we know about the red planet and its past, the more complex are the unanswered questions. In order to answer them, an ambitious long-term plan for the robotic and manned exploration of Mars has been established by the scientific community worldwide. To ensure success in answering the issues to be investigated on each step of the plan, the selection of “on board” payloads at mission level is specifically designed for achieving the best possible results. This selection also has modified the mission operation modes from a set of individual experiments to a cooperative science paradigm where all the instruments in the mission payload contribute jointly to achieve unprecedented scientific results. Collaboration not only between experiments but also between agencies for achieving major goals has been demonstrated as the optimum way forward for Mars exploration. This chapter presents a historical review, with a look into the future, of the human efforts aimed at understanding the red planet, focusing on the technological advances and scientific discoveries achieved that help answer some of the most thrilling and transcendental questions ever raised by humanity: Are we alone in the Universe
Diseño de una red de monitoreo del nivel piezométrico mediante el análisis multicriterio
El agua subterránea es un recurso natural vital para el suministro confiable y económico de agua para el consumo humano en zonas urbanas y rurales. De acuerdo con la UNESCO (2009), los sistemas de agua subterránea suministran el 48.23% del agua potable del mundo. Hoy en día, la mitad de las megalópolis del mundo y grandes ciudades en todos los continentes dependen del agua subterránea. El agua subterránea es susceptible a sufrir cambios en su cantidad y calidad, siendo estos cambios frecuentemente procesos muy lentos por lo que necesitan ser monitoreados. El monitoreo de un acuífero es un programa de medición continua y observación de la situación actual del agua subterránea en el espacio y tiempo
UNITSIM-Galaxies: Data release and clustering of emission-line galaxies
This is a pre-copyedited, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record Monthly Notices of the Royal Astronomical Society 510.4 (2022): 5392-5407 is available online at: https://academic.oup.com/mnras/article-abstract/510/4/5392/6505155?redirectedFrom=fulltextNew surv e ys such as European Space Agenc ys (ESA's) Euclid mission are planned to map with unprecedented precision the large-scale structure of the Universe by measuring the 3D positions of tens of millions of galaxies. It is necessary to develop theoretically modelled galaxy catalogues to estimate the expected performance and to optimize the analysis strategy of these surv e ys. We populate two pairs of (1 h -1 Gpc) 3 volume dark matter-only simulations from the UNIT project with galaxies using the Semi-Analytic Galaxy Evolution semi-analytic model of galaxy formation, coupled to the photoionization model GET EMLINES to estimate their H αemission. These catalogues represent a unique suite that includes galaxy formation physics and -thanks to the fixed-pair technique used -an ef fecti ve volume of ∼(5 h -1 Gpc ) 3 , which is several times larger than the Euclid surv e y. We present the performance of these data and create five additional emission-line galaxy (ELG) catalogues by applying a dust-attenuation model as well as adjusting the flux threshold as a function of redshift in order to reproduce Euclid-forecast d N /d z values. As a first application, we study the abundance and clustering of those model H αELGs: For scales greater than ∼5 h -1 Mpc, we find a scale- independent bias with a value of b ∼1 at redshift z ∼0.5, that can increase nearly linearly to b ∼4 at z ∼2, depending on the ELG catalogue. Model galaxy properties, including their emission-line fluxes (with and without dust extinction) are publicly availabl
ExoMars Raman Laser Spectrometer RLS, a tool for the potential recognition of wet target craters on Mars
In the present work, NIR, LIBS, Raman and XRD techniques have been
complementarily used to carry out a comprehensive characterization of a
terrestrial analogue selected from the Chesapeake Bay Impact Structure (CBIS).
The obtained data clearly highlight the key role of Raman spectroscopy in the
detection of minor and trace compounds, through which inferences about
geological processes occurred in the CBIS can be extrapolated. Beside the use
of commercial systems, further Raman analyses were performed by the Raman Laser
Spectrometer (RLS) ExoMars Simulator. This instrument represents the most
reliable tool to effectively predict the scientific capabilities of the
ExoMars/Raman system that will be deployed on Mars in 2021. By emulating the
analytical procedures and operational restrictions established by the ExoMars
mission rover design, it was proved that the RLS ExoMars Simulator is able to
detect the amorphization of quartz, which constitutes an analytical clue of the
impact origin of craters. On the other hand, the detection of barite and
siderite, compounds crystallizing under hydrothermal conditions, helps to
indirectly confirm the presence of water in impact targets. Furthermore, the
RLS ExoMars Simulator capability of performing smart molecular mappings was
also evaluated. According to the obtained results, the algorithms developed for
its operation provide a great analytical advantage over most of the automatic
analysis systems employed by commercial Raman instruments, encouraging its
application for many additional scientific and commercial purposes
La vid silvestre en México. Actualidades y potencial
En ocho capítulos se aborda el estado del arte de la vid silvestre en MéxicoEl estudio de las especies vegetales nativas de México representa un reto que cada día más investigadores mexicanos asumen. Durante muchos años, el apoyo a la investigación pública ha sido mínimo; desde el punto de vista agronómico es insuficiente para avanzar a la velocidad que requiere nuestro país para afrontar problemas de producción y distribución de alimentos. Por esa razón, entre otras, me es grato presentar esta obra que compila parte de los trabajos de la Red de Vid Silvestre patrocinada por el Sistema Nacional de Recursos Fitogenéticos (sinarefi) dependiente de la sagarpa; trabajos apuntalados por investigadores que sin pertenecer a la red han colaborado en el estudio de las plantas del género Vitis. En este libro se muestra el potencial del país para aprovechar el recurso vid, empleado desde antes de la conquista española por nativos mexicanos que conocían sus bondades. Es necesario continuar el avance en el conocimiento de este recurso, por ello el presente libro pretende invitar a toda persona interesada en contribuir con el rescate y conservación de las vides mexicanas. Los autores y editores, así como las instituciones en donde laboramos y aquellas que patrocinan estas investigaciones, esperamos se cumpla este objetivo y que el lector, alumno, profesor, investigador, público en general, disfrute esta lectura y, sobre todo, se interese en el recurso VitisSEP, SINAREFI, UAEME
Raman analysis of a shocked planetary surface analogue: Implications for habitability on Mars
The scientific aims of the ExoMars Raman laser spectrometer (RLS) include identifying biological signatures and evidence of mineralogical processes associated with life. The RLS instrument was optimised to identify carbonaceous material, including reduced carbon. Previous studies suggest that reduced carbon on the Martian surface (perhaps originating from past meteoric bombardment) could provide a feedstock for microbial life. Therefore, its origin, form, and thermal history could greatly inform our understanding of Mars' past habitability. Here, we report on the Raman analysis of a Nakhla meteorite analogue (containing carbonaceous material) that was subjected to shock through projectile impact to simulate the effect of meteorite impact. The characterisation was performed using the RLS Simulator, in an equivalent manner to that planned for ExoMars operations. The spectra obtained verify that the flight-representative system can detect reduced carbon in the basaltic sample, discerning between materials that have experienced different levels of thermal processing due to impact shock levels. Furthermore, carbon signatures acquired from the cratered material show an increase in molecular disorder (and we note that this effect will be more evident at higher levels of thermal maturity). This is likely to result from intense shearing forces, suggesting that shock forces within basaltic material may produce more reactive carbon. This result has implications for potential (past) Martian habitability because impacted, reduced carbon may become more biologically accessible. The data presented suggest the RLS instrument will be able to characterise the contribution of impact shock within the landing site region, enhancing our ability to assess habitability
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Obstetric outcomes of sars-cov-2 infection in asymptomatic pregnant women
Altres ajuts: Fondo Europeo de Desarrollo Regional (FEDER)Around two percent of asymptomatic women in labor test positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Spain. Families and care providers face childbirth with uncertainty. We determined if SARS-CoV-2 infection at delivery among asymptomatic mothers had different obstetric outcomes compared to negative patients. This was a multicenter prospective study based on universal antenatal screening for SARS-CoV-2 infection. A total of 42 hospitals tested women admitted for delivery using polymerase chain reaction, from March to May 2020. We included positive mothers and a sample of negative mothers asymptomatic throughout the antenatal period, with 6-week postpartum follow-up. Association between SARS-CoV-2 and obstetric outcomes was evaluated by multivariate logistic regression analyses. In total, 174 asymptomatic SARS-CoV-2 positive pregnancies were compared with 430 asymptomatic negative pregnancies. No differences were observed between both groups in key maternal and neonatal outcomes at delivery and follow-up, with the exception of prelabor rupture of membranes at term (adjusted odds ratio 1.88, 95% confidence interval 1.13-3.11; p = 0.015). Asymptomatic SARS-CoV-2 positive mothers have higher odds of prelabor rupture of membranes at term, without an increase in perinatal complications, compared to negative mothers. Pregnant women testing positive for SARS-CoV-2 at admission for delivery should be reassured by their healthcare workers in the absence of symptoms
In situ science on Phobos with the Raman spectrometer for MMX (RAX): preliminary design and feasibility of Raman meausrements
Mineralogy is the key to understanding the origin of Phobos and its position in the evolution of the Solar System. In situ Raman spectroscopy on Phobos is an important tool to achieve the scientifc objectives of the Martian Moons eXploration (MMX) mission, and maximize the scientifc merit of the sample return by characterizing the mineral composition and heterogeneity of the surface of Phobos. Conducting in situ Raman spectroscopy in the harsh environment of Phobos requires a very sensitive, compact, lightweight, and robust instrument that can be carried by the compact MMX rover. In this context, the Raman spectrometer for MMX (i.e., RAX) is currently under development via international collaboration between teams from Japan, Germany, and Spain. To demonstrate the capability of a compact Raman system such as RAX, we built an instrument that reproduces the optical performance of the fight model using commercial of-the-shelf parts. Using this performance model, we measured mineral samples relevant to Phobos and Mars, such as anhydrous silicates, carbonates, and hydrous minerals. Our measurements indicate that such minerals can be accurately identifed using a RAX-like Raman spectrometer. We demonstrated a spectral resolution of approximately 10 cm−1, high enough to resolve the strongest olivine Raman bands at ~820 and ~850 cm−1, with highly sensitive Raman peak measurements (e.g., signal-to-noise ratios up to 100). These results strongly suggest that the RAX instrument will be capable of determining the minerals expected on the surface of Phobos, adding valuable information to address the question of the moon’s origin, heterogeneity, and circum-Mars material transport
New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
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