21 research outputs found

    Detecting and Characterising atmospheric gravity waves on Mars' atmosphere - Final results using data from OMEGA/Mars Express

    Get PDF
    We present the final results from the detection and characterisation of mesoscale waves on the lower clouds of Mars [1] using images from the Observatoire pour la Minéralogie, l’Eau, les Glaces et l’Activité (OMEGA) [2] onboard the European Mars Express (MEx) space mission [3]. We used image navigation and processing techniques based on contrast enhancement and geometrical projections to characterise morphological properties of the detected gravity waves (GW), such as horizontal wavelength or packet length. Our study covers 25 months of data spanning from Jan. 2004 to Jan. 2006, and from June to July 2007, corresponding to a one Martian year [MY26- MY27]. Out of 148 detected wave packets, we were able to characterise 61 across more than 4000 images covering a broad region of the Martian globe. Our results reveal that waves exhibit an average horizontal wavelength of 23 km, which is consistent with previous observations [4,5]. We also extend the study by characterising their packet width, length and orientation. Taking advantage of the large dataset available from the OMEGA instrument, we also conducted a spatial and temporal investigation of the waves, namely their occurrence in specific local times and solar longitudes. Our characterisation showed a higher frequency of GW during daytime hours, particularly within the 13-15 LTST range. Concerning the solar longitude that is a measure of the Martian seasons, we noted that GW activity is prevalent during the winter season in both hemispheres, suggesting a relationship between seasonal variations and gravity wave generation, which was previously mentioned in the literature [6–8]. We will also present the preliminary results of GW using the HRSC instrument

    Livestock-associated MRSA colonization of occupational exposed workers and households in Europe: a review

    Get PDF
    The worldwide escalation in antibiotic resistant microorganisms has sustained the increasing concerns regarding antibiotics extensive use in animal food industry, which can result in a selection pressure that is driving the emergence of strains such as methicillin-resistant staphylococcus aureus (MRSA). Human MRSA infections are a well-known cause of numerous hospitalizations and deaths associated with extremely high mortality rates for invasive infections. Both animals and humans can become bacterial reservoirs of Livestock Associated MRSA (LA-MRSA) in which colonization predisposes to staphylococcal acquisition in clinical settings and to transfer the infection to others including household members. Biomonitoring of occupational exposed individuals which spend several hours per day in direct contact with MRSA-positive animals and thus are irrefutably exposed to a high risk of nasal colonization is imperative in order to develop effective preventive strategies. Here we performed an extensive review regarding the prevalence of LA- MRSA colonization in both occupational exposed individuals and their house-holds in a European context.info:eu-repo/semantics/publishedVersio

    Identification of tetracyclic lactams as NMDA receptor antagonists with potential application in neurological disorders

    No full text
    N-Methyl-D-aspartate receptors (NMDARs) are crucial for the normal function of the central nervous system (CNS), and fundamental in memory and learning-related processes. The overactivation of these receptors is associated with numerous neurodegenerative and psychiatric disorders. Therefore, NMDAR is considered a relevant therapeutic target for many CNS disorders. Herein, we report the synthesis and pharmacological evaluation of a new scaffold with antagonistic activity for NMDAR. Specifically, a chemical library of eighteen 1-aminoindan-2-ol tetracyclic lactams was synthesized and screened as NMDAR antagonists. The compounds were obtained by chiral pool synthesis using enantiomerically pure 1-aminoindan-2-ols as chiral inductors, and their stereochemistry was proven by X-ray crystallographic analysis of two target compounds. Most compounds reveal NMDAR antagonism, and eleven compounds display IC values in a Ca entry-sensitive fluo-4 assay in the same order of magnitude of memantine, a clinically approved NMDAR antagonist. Docking studies suggest that the novel compounds can act as NMDAR channel blockers since there is a compatible conformation with MK-801 co-crystallized with NMDAR channel. In addition, we show that the tetracyclic 1-aminoindan-2-ol derivatives are brain permeable and non-toxic, and we identify promising hits for further optimization as modulators of the NMDAR function.This work was supported by FCT (Fundaç~ao para a Ci^encia e a Tecnologia, I.P.) through iMed.ULisboa (UID/DTP/04138/2019), Principal Researcher grant CEECIND/01772/2017 (M. M. M. Santos), and PhD fellowships SFRH/BD/117931/2016 (M. Espadinha) and SFRH/BD/121664/2016 (R. Lopes). Financial support from FCT and Portugal 2020 to the Portuguese Mass Spectrometry Network (Rede Nacional de Espectrometria de Massa e RNEM; LISBOA-01-0145- FEDER-402-022125) is also acknowledged. M.I.R.-F. thanks funding from the Spanish Ministry of Science, Innovation and Universities (grant RTI2018-093955-B-C21) and the technical assistance of Ms. Cristina Tortosa (European contract for young professionals). C.d.l.R. thanks funding from Instituto de Salud Carlos III, Madrid, Spain (grant PI16/01041 and PhD fellowship FI17/00079 for L. Viejo)
    corecore