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Tag: University of Seville

  • New study about the ‘tsunami’ in Venus’s clouds

    New study about the ‘tsunami’ in Venus’s clouds

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    Newswise — A group of scientists from the University of Seville, in collaboration with experts from the University of the Basque Country, has led the first detailed study of the evolution of the discontinuity of Venus’s clouds, a gigantic atmosphere wave with the appearance of a “tsunami” that is propagated in the planet’s deepest clouds and which, it is believed, may be playing a very significant role in the acceleration of Venus’s fast-moving atmosphere. The observations were carried out non-stop for more than 100 days. “This observational feat was possible thanks to the collaboration of amateur astronomers from various countries, who have been the leading lights in the worldwide campaign of observations coordinated with the Japanese mission Akatsuki in 2022,” explains the University of Seville researcher and member of this mission, Javier Peralta. 

    This paper published in Astronomy & Astrophysics has also revealed a truly unexpected event, since the ultraviolet images taken in June by the UVI camera on board the Akatsuki mission (which allows us to see the highest clouds in Venus) seem to reflect the fact that the discontinuity was capable of propagating for a few hours to around 70 km above the surface of Venus. “This is surprising, because until now the discontinuity appeared ‘trapped’ in the deepest clouds and we had never observed it at such a high altitude,” explains Peralta.

    The astrophysicist Javier Peralta was responsible for designing in 2022 the strategy for WISPR’s Venus observations during the spacecraft’s approach/departure manoeuvres during Parker’s flybys. He also contributed to physical interpretation of the observations, comparing thermal emission images of the surface of Venus taken by WISPR (NASA-Parker) and the IR1 camera (JAXA-Akatsuki).

    In this vein, the Akatsuki images not only point to the fact that the discontinuity may have propagated to Venus’ upper clouds, but also help us to understand the reasons for this displacement. In general, regions where winds have the same speed as a wave act as a physical “barrier” for the propagation of that wave. Because winds gradually increase with height on Venus and have higher speeds than the discontinuity at the peak of the clouds, the discontinuity attempts to propagate upwards from the deep clouds, but meets this obstacle on its way and eventually dissipates. Thus, experts were surprised when they measured the winds in the high clouds with Akatsuki: they found that they were unusually slow in the first half of 2022, several times slower than the discontinuity itself. And if the winds grow much more slowly with height, the discontinuity takes longer to find atmospheric regions as fast as itself, allowing it to propagate to higher altitudes.

    “Measuring the winds on Venus is essential to try to explain why Venus’s atmosphere spins 60 times faster than the surface. This atmospheric phenomenon is known as superrotation. It also happens on the Saturn moon Titan and on many exoplanets, but after more than half a century o research we still cannot satisfactorily explain it,” explains this researcher.

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  • Spanish physicists disagree with the Sleep Society and endorse the time change in the USA

    Spanish physicists disagree with the Sleep Society and endorse the time change in the USA

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    Newswise — Putting the clocks forward does not affect the length of the daylight period – a natural phenomenon beyond human control – but rather makes it possible to optimise its use by using early morning light for activities and thus to enjoy more hours of leisure time during the day. This is the crux of the article that José María Martín-Olalla and Jorge Mira Pérez, lecturers at the University of Seville (US) and the University of Santiago de Compostela (USC), have just published in the journal Sleep, where they analyse the naturalness and usefulness of putting the clocks forward, in response to a manifesto of the Sleep Research Society that calls for its abolition in the United States and the adoption of permanent winter time. Regarding the time change due to take place in the United States on 12 March, the researchers believe that “cancelling the time change will not improve the current scenario in the range of latitudes where the United States is located.”

    However, they believe that the springtime change occurs too early in the United States, and the autumn time change is too late, which particularly affects people who work earlier in the working day. In the view of the researchers, if it is accepted that the dates of time changes must be adjusted for the benefit of the people, the springtime change should occur after the equinox, in early April, as was the case in the United States until 2007. “Likewise, if the autumn time change were to occur in early October, as it was until 1954, many workers and schoolchildren would no longer suffer the stressful twilight hours of October mornings,” the authors explain in their paper.

    The researchers go on to argue that modern societies, governed by pre-set schedules, can only seasonally regulate their activities by one hour increments, as with the current change. The temporary disruption, according to experts, is offset by better alignment of when people begin their activities and sunrise. In their paper they point out that, in practice, people do not change their schedules after the changes, which is an indication of the success of the measure, according to Jorge Mira Pérez and José María Martín Olalla. “It is not easy to keep a strict schedule all year round, when sunrise times change from winter to summer, we relieve that need by seasonal time changes, and if we didn’t, we would change working hours seasonally,” they say.

    Pre-adaptation
    The authors stress the fact that in winter days are short, which affects human activity, while summer nights are also shorter, which affects people’s ability to fall asleep, whether or not they change the hour. “We highlight the fact that winter sunrise and summer sunset are twelve hours apart, irrespective of latitude. If human activity begins with the winter sunrise and seasonal time regulation is applied, then the start of human activity in summer and the summer sunset are separated by eleven hours, which is probably sufficient for adequate sleep. Those who start their activities earlier than the winter sunrise time may find that the clock changes are less appropriate in summer. But it is notable that the changes themselves have helped to prevent human activity from taking place before the winter sunrise,” they explain.

    “In summer, either you go to bed early, soon after nightfall, or you get up late, long after dawn,” explains Jorge Mira, who was a member of the Spanish Government’s commission to examine the official time. José María Martín Olalla, who researches the social uses of time, with particular emphasis on human adaptation to the seasonal cycle of light and darkness, adds “we know the disadvantages of putting the clocks forward that is, the nuisance of changing the clock twice a year; we forget its benefits and we don’t know the drawbacks of not having done so.”

    The greatest concern of the chronobiological and sleep community lies in the risks of putting the clocks forward. Thus, the authors propose preventative adaptation by, for example, changing the alarm clock’s time in the weeks running up to putting the clock forward in spring by four increments of 15 minutes, three of 20 minutes or two of 30 minutes. In Europe, the time change will take place on Sunday, 26 March, while in New Zealand, Australia and Chile it will take place on Sunday, 3 April.

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  • Footprints indicate the presence of man in Southern Spain in the Middle Pleistocene, 200,000 years earlier than previously thought

    Footprints indicate the presence of man in Southern Spain in the Middle Pleistocene, 200,000 years earlier than previously thought

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    Newswise — The researcher and GRS Radioisotopes technician from the University of Seville, Jorge Rivera, has participated in an incredible discovery that is unique in Europe. After applying optically-stimulated luminescence technique at the Centre for Research, Technology and Innovation laboratories at the University of Seville (CITIUS) and at CENIEH, to hominin footprints found at Matalascañas in 2020, it was possible to determine that they are in fact 200,000 years older than previously suspected. This would mean that pre-Neanderthals would have lived in the Doñana area during the Middle Pleistocene, around 295,800 years ago.

    The research, led by the Professor of Paleontology at the University of Huelva, Eduardo Mayoral, was published by Scientific Reports, one of the publications of the Nature group, on 19 October.

    The technique

    Optically-stimulated luminescence is a method used to find the absolute age of sediments that have been fully exposed to sunlight.

    Scientific milestone

    The discovery in June 2020 of hominin footprints more than 106,000 years old next to El Asperillo (Matalascañas, Huelva) was a revolution for the scientific world, so much so that it was considered one of the most important discoveries of that year. But now, the publication of this new paper has confirmed what some experts suspected at the time: those footprints were much older and are in fact 200,000 years older than previously thought. While it was previously placed in the Upper Pleistocene, the evidence now points clearly to the Middle Pleistocene, and to its being 295,800 years old, making it a unique record in Europe, since there is no better site in the world in terms of number, age and area than that of the El Asperillo beach for hominin fossil footprints.

    After collecting samples from the various levels, and another two later to compare the first results, the age of the fossil remains was established and points to the Middle Pleistocene, a crucial moment between different climatic stages, between a warm period, MIS 9 (360,000-300,000 years ago), in transition to MIS 8 (300,000-240,000 years ago), in which a major glaciation took place.

    The age is thus specified at 295,800 years, with a margin of error of 17,800 years, according to the data collected from the four samples of sedimentary levels in the cliffs of El Asperillo where the site was found, initially 87 footprints, which now has a record of more than 300 footprints, of which 10% are considered well-preserved. With the exception of those from Matalascañas, it is noted that no other hominin footprints are known between the climatic stages MIS9 and MIS 8 of the Middle Pleistocene. That is why it is questioned whether they belong to Neanderthals.

    But are they Neanderthals?

    At first they were thought to be Neanderthals, but that is now in doubt. The main hypothesis among the scientists is that they are individuals of the Neanderthal lineage, among which Homo heidelbergensis and Homo neanderthalensis have been associated. The hypothesis that they are pre-neanderthal hominins is feasible. Precisely for this reason, the Matalascañas footprints are now more valuable due to their contribution to the fossil records of hominins in the Middle Pleistocene, which is very poor in Europe because of the scarcity of deposits with footprints. Until now, according to the Nature paper, footprints this period have only been found at Terra Amata and Roccamonfina (Italy), which were dated to between 380,000 and 345,000 years ago, with records of Homo heidelbergensis. They are the only ones older than that at Huelva in this era. After these, Biache-Vaast (France) and Theopetra (Greece) sites, from 236,000 to 130,000 years ago, are attributed to Homo neanderthalensis. In this context, the length range of all the footprints found at Matalascañas, from 14 to 29 centimetres, is similar to that found at European sites, such as Theopetra (14-15 centimetres), Roccamonfina (24-27 cm) and Terra Amata (24 cm).

    In any case, the experts highlight the singularity of the Matalascañas discovery, whose new dating has questioned the existing paradigms and has required a deep analysis before accepting its conclusions. 

    The new chronology now establishes a change in the scenario that then prevailed on the coast of the Gulf of Cádiz, with human settlements in a more temperate and humid climate than in the rest of Europe, with high water tables and abundant vegetation.

    In that same period the sea level would have been about 60 metres below its current level. This implies that the coast would be more than 20 kilometres from where it is today, which is how there would have been a great coastal plain, with large flood-prone areas, in which the footprints discovered in mid-2020 would have been made.

    The site’s new dating also affects the vertebrate animals found, since the hominin traces there also included footprints of large mammals such as straight-tusked elephants, gigantic bulls (aurochs) and boars. It was the fauna that inhabited Doñana 300,000 years ago and not 100,000 years ago, as other investigations stated.

    International team

    The paper, New dating of the Matalascañas footprints provides new evidence of the Middle Pleistocene (MIS 9-8) hominin paleoecology in southern Europe, is the result of the work of an international team of scientists led by the Professor of Paleontology at the University of Huelva, Eduardo Mayoral, alongside the lecturer Antonio Rodríguez and Professor of Stratigraphy Juan Antonio Morales, all of the Department of Earth Sciences of the Faculty of Experimental Sciences, who are also members of the Centre for Scientific and Technological Research (CCTH) at UHU, as well as Jérémy Duvau, a researcher at the Museum National d’Histoire Naturelle (France); Ana Santos, from the University of Oviedo; Ricardo Díez-Delgado, from the Doñana-CSIC Biological Station; Jorge Rivera, from the University of Seville; Asier Gómez-Olivencia, from the University of the Basque Country; and Ignacio Díaz, from the University of Río Negro (Argentina).

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  • The Origin-of-Life Molecule, a Key to Cancer Research

    The Origin-of-Life Molecule, a Key to Cancer Research

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    Newswise — RNA, the molecule that gave rise to life, has been shown to be essential for repairing human genetic material and preventing mutations that might lead to developing cancer. Recent advances in research, such as those published by the research team of Daniel Gómez Cabello at the University of Seville, propose this compound as a therapeutic target for developing tailored strategies for treating cancer.

    The RNA polymerase enzyme, the RNA production machine in cells, is essential for repairing breakages in human DNA safely and reliably. RNA production is essential for healthy cells but especially for tumour cells, which require much more activity by this enzyme to grow uncontrolled.

    The study revealed that RNA synthesis inhibition with the THZ1 compound and analogues after therapies that cause DNA breakages, such as radiation therapy, greatly increases tumour cells’ sensitivity to death. “This study provides clues on how to improve conventional therapies and achieve a higher success rate with treatments. Although there is still a long way to go to be able to use these RNA polymerase inhibitors in the clinical setting, clinical trials are currently underway based on this enzyme for treating cancer”, explained the Principal Investigator, Daniel Gómez-Cabello. “Increasing the knowledge on how to use these compounds in a safer and more tailored manner allows us to address as best as possible the treatment of cancer”, added the researcher Diana Aguilar-Morante, the study’s co-author.

    This research by the Biomedical Institute of Seville and the University of Seville, in collaboration with the Danish Cancer Society, has been published in the prestigious journal Nature Communications. Both researchers return to Spain from Denmark and have been able to continue their research thanks to contracts funded by the Government of Andalusia and the Spanish Association against Cancer (AECC). “Thanks to the AECC, we have been able to continue with these studies and move this project forward”, explained the author.

    Currently, these researchers are working on the mechanisms of how RNA, the original molecule that enables life, can serve as a tool for treating diseases. “Once we have observed that selectively inhibiting RNA production boosts the utility of radiation therapy in cancer cells and does not drastically affect the rest of the cells, we will start researching it in various types of cancer, such as glioblastoma and paediatric neuroblastoma”, commented Diana Aguilar-Morante. “At this point, our challenge will be to improve the efficiency of these new RNA production inhibitors and reduce the side effects that can occur in patients with cancer”, stated Gómez-Cabello.

    RNA, the molecule that gave rise to life, has been shown to be essential for repairing human genetic material and preventing mutations that might lead to developing cancer. Recent advances in research, such as those published by the research team of Daniel Gómez Cabello at the University of Seville, propose this compound as a therapeutic target for developing tailored strategies for treating cancer.

    The RNA polymerase enzyme, the RNA production machine in cells, is essential for repairing breakages in human DNA safely and reliably. RNA production is essential for healthy cells but especially for tumour cells, which require much more activity by this enzyme to grow uncontrolled.

    The study revealed that RNA synthesis inhibition with the THZ1 compound and analogues after therapies that cause DNA breakages, such as radiation therapy, greatly increases tumour cells’ sensitivity to death. “This study provides clues on how to improve conventional therapies and achieve a higher success rate with treatments. Although there is still a long way to go to be able to use these RNA polymerase inhibitors in the clinical setting, clinical trials are currently underway based on this enzyme for treating cancer”, explained the Principal Investigator, Daniel Gómez-Cabello. “Increasing the knowledge on how to use these compounds in a safer and more tailored manner allows us to address as best as possible the treatment of cancer”, added the researcher Diana Aguilar-Morante, the study’s co-author.

     

    This research by the Biomedical Institute of Seville and the University of Seville, in collaboration with the Danish Cancer Society, has been published in the prestigious journal Nature Communications. Both researchers return to Spain from Denmark and have been able to continue their research thanks to contracts funded by the Government of Andalusia and the Spanish Association against Cancer (AECC). “Thanks to the AECC, we have been able to continue with these studies and move this project forward”, explained the author.

    Currently, these researchers are working on the mechanisms of how RNA, the original molecule that enables life, can serve as a tool for treating diseases. “Once we have observed that selectively inhibiting RNA production boosts the utility of radiation therapy in cancer cells and does not drastically affect the rest of the cells, we will start researching it in various types of cancer, such as glioblastoma and paediatric neuroblastoma”, commented Diana Aguilar-Morante. “At this point, our challenge will be to improve the efficiency of these new RNA production inhibitors and reduce the side effects that can occur in patients with cancer”, stated Gómez-Cabello.

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