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BACKGROUND AND OBJECTIVES: Atmospheric zinc corrosion in the Mexico City Metropolitan area has long been attributed mainly to the effect of pollutants such as sulfur dioxide. There are changes in the urban atmosphere's chemical composition due to the implementation of air quality policies focused on reducing the emission of sulfur dioxide and other pollutants. This study's objectives were to estimate and map the contribution of nitric acid on zinc's atmospheric corrosion process. METHODS: The impact of nitric acid on zinc is feasible to estimate using a function for a multi-pollutant situation. This function contemplates the sum of two contributions: one of nitric acid and another that includes sulfuric acid and climatic parameters. The multi- pollutant function is suitable to apply in areas without the strong influence of chlorides and tropical and subtropical climates, comparable to the Mexico City Metropolitan area. FINDINGS: The results showed that spatial and temporal estimation of corrosion rates in grams per square meter of zinc was made for 2015-2019, using data modeling in a geographic information system. The maps of corrosion rates allowed us to visualize that, in general, the "southwest" zone has the most significant effects and that the lowest corrosion rates were presented in 2019 as an outcome of the implementation of air quality programs. Furthermore, a contribution of nitric acid up to 32% to the zinc corrosion rate was estimated. CONCLUSION: The construction of corrosion rate maps provides a spatial and temporal estimate that allows visualizing areas where zinc materials are at risk corrosion due to the dispersion of atmospheric pollutants and climatic parameters. Likewise, it can represent a decision-making tool for the implementation of atmospheric corrosion studies of materials. [ABSTRACT FROM AUTHOR]

The technique of mutual approximations accurately gives the central instant of the maximum apparent approximation of two moving natural satellites in the plane of the sky. This can be used in ephemeris fitting to infer the relative positions of satellites with high precision. Only mutual phenomena – occultations and eclipses – can achieve better results. However, mutual phenomena only occur every six years in the case of Jupiter. Mutual approximations do not have this restriction and can be observed at any time in the year as long as the satellites are visible. In this work, we present 104 central instants determined from the observations of 66 mutual approximations between the Galilean moons carried out at different sites in Brazil and France during the period 2016–2018. For 28 events, we have at least two independent observations. All telescopes were equipped with a narrow-band filter centred at 889 nm with a width of 15 nm to eliminate the scattered light from Jupiter. The telescope apertures ranged between 25 and 120 cm. For comparison, the precision of the positions obtained with classical CCD astrometry is about 100 mas, for mutual phenomena it can be 10 mas or less, and the average internal precision obtained with mutual approximations is 11.3 mas. This new type of simple, yet accurate, observations can significantly improve the orbits and ephemeris of Galilean satellites and thus it can be very useful for the planning of future space missions to the Jovian system. [ABSTRACT FROM AUTHOR]

Background: The European Network of Medical Residents in Public Health (EuroNet MRPH) is a non-profit, international, independent and non-governmental network of national associations of public health residents around Europe. Objectives: To describe the results accomplished by EuroNet MRPH and to show networking opportunities provided to medical residents in public health (MRPH) from 2011 to 2021. Results: EuroNet’s mission is to improve and facilitate connection between MRPH, to promote pan-European Research, and to facilitate international mobility. Digital and quarterly face-toface meetings are used as a way of communication. Since 2011, 10 European MRPH associations and 4 individual members have joined the network, representing the UK, France, Spain, Italy, Portugal, Ireland, the Netherlands, Croatia, Slovenia, Turkey, Malta, Poland, Bosnia and Herzegovina, and Austria. In this period, 27 face-to-face meetings have been organised, promoting cooperation and exchanging of ideas between MRPH. Moreover, three working groups (WG) have been established, focusing on research, internships, and communication. Regarding research, studies about e-cigarettes, conflicts of interest, and the impact of COVID-19 on mental health of MRPH have been conducted. When it comes to internships, more than 20 possible destinations and an online form are available on our website, providing MRPH information and support. Finally, thanks to the communication WG, 20 newsletters have been published, sharing experiences and thoughts from members of the network. Moreover, EuroNet has an established presence in social media, with active accounts in Twitter, Instagram and Facebook, where public health information and opportunities for young professionals are promoted. Conclusions: In the last ten years, EuroNet MRPH has actively promoted networking opportunities among European Medical Residents in Public Health. Key messages: Enhancing international cooperation among young public health professionals is fundamental in order to face current and future public health challenges. EuroNet MRPH represents a useful tool to promote collaboration among young public health professionals. [ABSTRACT FROM AUTHOR]