Researchers are tracking the different strains of SARS-CoV-2 and studying how they spread through our population and our bodies.www.quantamagazine.org
The history of dogs has been intertwined, since ancient times, with that of the humans who domesticated them.phys.org
Cambridge University team say their findings could be used to spot people at risk from radicalisationwww.theguardian.com
For the first time, a NASA mission has made multi-height measurements of the solar chromosphere’s magnetic field. The observations extend our measurement capability into a region of the Sun that has so far eluded scientific grasp.www.nasa.gov
Italy’s Mount Etna, one of the world’s most active volcanoes, has erupted twice in less than 48 hours, spewing a fountain of lava and ash into the sky. This Copernicus Sentinel-2 image has been processed to show the lava flow in bright red.www.esa.int
Science magazine: As Samuel West combed through a paper that found a link between watching cartoon violence and aggression in children, he noticed something odd about the study participants. There were more than 3000 -- an unusually large number -- and they were all 10 years old. "It was just too pe...science.slashdot.org
Previously believed to be only man-made, a natural example of a functioning gear mechanism has been discovered in a common insect - showing that evolutionwww.cam.ac.uk
Le principal assureur de santé d’Israël a indiqué dimanche 14 février que le vaccin Pfizer/BioNTech contre le coronavirus était efficace à 94 % selon une étude menée sur plus d’un million de personnes vaccinées.https://www.ouest-france.fr/sante/vaccin/covid-19-le-vaccin-pfizer-biontech-efficace-a-94-selon-une-etude-menee-sur-un-million-d-israeliens-7154976
[...] ses chercheurs ont testé 600 000 personnes ayant reçu les deux doses recommandées du vaccin et un nombre équivalent de personnes n’ayant pas reçu d’injection.
« Il y avait une réduction de 94 % du taux d’infection symptomatique et une baisse de 92 % du taux de maladie grave, comparé à 600 000 (sujets) similaires n’ayant pas été vaccinés », rapporte l’assureur dans un communiqué en hébreu.
’assureur précise que l’étude a jusqu’à présent été menée sur des personnes au moins sept jours après qu’elles ont reçu leur deuxième injection et sera étendue par la suite. « Chaque nouvelle semaine qui passe nous permettra de rendre l’évaluation plus précise. »
Clalit est le plus important des quatre assureurs de santé du pays, qui couvrent l’ensemble de la population. Les assureurs de santé sont directement responsables des vaccinations et de la collecte des données sur leur efficacité.
Israël a officiellement recensé 723 038 cas de Covid-19, dont 5 368 morts.
Le vaccin contre le Covid-19 de Pfizer/ BioNTetch montre une efficacité de 94 % en Israël, selon une enquête menée sur un million de vaccinés, soit un chiffre quasi identique aux essais cliniques.www.ouest-france.fr
In mitochondria from various species, the OXPHOS complexes reside mainly in the invaginated cristae membranes, as opposed to the inner boundary membrane (IBM) that parallels the mitochondrial outer membrane. However, the IBM contains dynamic contact sites enriched for translocases that import proteins from the cytosol. As the majority of OXPHOS components are imported and need to be integrated in assembly with the mtDNA-encoded components, where does intramitochondrial translation occur? Here we report: 1) a method for visualizing protein synthesis in human mitochondria at super resolution; 2) that synthesis is enriched at cristae membranes, in preference to the IBM; and 3) that sites of translation are spatially separated from RNA granules where RNA processing, maturation, and mitoribosomal assembly occur. All study data are included in the article and/or supporting information.www.pnas.org
Simultaneously measuring the nanoscale motion and forces that molecular machines generate provides insights into how they work mechanically to fulfill their cellular function. To study these machines, Sudhakar et al. developed germanium semiconductor nanospheres as probes for so-called optical tweezers. With these high–refractive index nanospheres, they improved the resolution of optical tweezers and discovered that the motor kinesin takes 4-nanometer substeps. Further, instead of detaching from their microtubule track under load, motors slid back on it, enabling rapid reengagement in transport. The new technology will allow investigation of a range of other proteins and their behaviors at nanometer scales. Science , this issue p. [eabd9944][1]### INTRODUCTION Cytoskeletal motors drive many essential mechanical processes inside cells. For example, kinesin motors are key for cell division or vesicle transport. Kinesin-1 transports cargo along microtubules by coupling adenosine 5′-triphosphate (ATP) hydrolysis to perform mechanical work against piconewton loads. This force generation and overall transport distance are limited by motor detachment. However, how kinesins walk and detach is still unclear. To simultaneously measure the nanoscale motion and forces of molecular machines, optical tweezers are often used. In the tight, mostly infrared laser focus of optical tweezers, small dielectric particles can be trapped and used as handles for sensitive position and force measurements. Because optical forces scale with the particle volume, piconewton force measurements with nanoparticles require a high laser power. This high power leads to excessive heating and precludes biological measurements. Therefore, for biological single-molecule measurements, micrometer-sized probes are used. However, such probes have a large hydrodynamic drag and therefore lack the spatiotemporal resolution to unravel important fast or small details in the mechanochemistry of molecular machines. These details remain hidden in the storm of Brownian motion. ### RATIONALE To overcome this practical resolution limit of optical tweezers and resolve so-far hidden conformational changes of proteins, we sought to compensate the volume scaling of optical trapping forces by the use of probe materials with a very high refractive index and low light absorption. This compensation should allow the use of nanometer-sized probes and the generation of piconewton optical forces without detrimental heating but with improved temporal response and spatial precision. Promising materials include silicon and germanium that become transparent in the near-infrared, with very high refractive indices exceeding 4. However, efficient methods to fabricate such semiconductor nanospheres suitable for optical trapping do not exist. ### RESULTS We developed a solution-based method to synthesize germanium nanospheres. With a diameter of roughly 70 nm, they are about an order of magnitude smaller as compared with commonly used microspheres and still allowed piconewton force measurements. To find out how kinesin works mechanically, we developed an in vitro reconstituted assay. To this end, we coated the nanospheres with a lipid bilayer [the white rim in the transmission electron microscopy (TEM) image] to mimic vesicles and to be roughly their size inside cells. When we bound kinesin-1 to these “vesicles” and measured the interaction of single motors with microtubules under piconewton tension, we discovered that each hydrolysis cycle is broken up into two 4-nm center-of-mass substeps. The durations of these substeps alternated in their force and ATP dependence, with the duration of one of the substeps being nearly independent of both parameters. Furthermore, when subjected to hindering loads, motors never detached from the microtubule. Instead, motors slipped along the microtubule in 8-nm steps on microsecond time scales. These slip steps are consistent with a bond-rupture model that involves protein friction between the motor and its track. Unexpectedly, motors usually did not detach after a slip event but reengaged in motility that rescued cargo transport. ### CONCLUSION Germanium nanospheres are promising for bioimaging, sensing, optoelectronics, nanophotonics, and energy storage. For optical trapping, the nanospheres open a new temporal window by which to uncover hidden dynamics in molecular machines. The direct observation of load-bearing kinesin substeps resolves a long-standing controversy. Slipping and rescues should allow load distribution and synchronization when motors operate in teams. Understanding their mechanochemistry is important for a better understanding of cellular transport and other essential molecular functions of kinesins, with implications, for example, for neurodegenerative diseases and cancer. ![Figure][2]</img> Ultraresolution kinesin traces with optically trapped germanium nanospheres. Kinesins are molecular machines that transport vesicles along microtubules inside cells. Membrane-coated germanium nanospheres (TEM micrograph, left) improved the spatiotemporal resolution of optical tweezers and allowed the measurement of substeps during the normal kinesin stepping cycle. Under load, kinesins did not detach but slipped along the microtubule, which led to the discovery of rescues for vesicle transport. Kinesin motors are essential for the transport of cellular cargo along microtubules. How the motors step, detach, and cooperate with each other is still unclear. To dissect the molecular motion of kinesin-1, we developed germanium nanospheres as ultraresolution optical trapping probes. We found that single motors took 4-nanometer center-of-mass steps. Furthermore, kinesin-1 never detached from microtubules under hindering load conditions. Instead, it slipped on microtubules in microsecond-long, 8-nanometer steps and remained in this slip state before detaching or reengaging in directed motion. Unexpectedly, reengagement and thus rescue of directed motion was more frequent. Our observations broaden our knowledge on the mechanochemical cycle and slip state of kinesin. This state and rescue need to be accounted for to understand long-range transport by teams of motors. [1]: /lookup/doi/10.1126/science.abd9944 [2]: pending:yesscience.sciencemag.org
For Valentine’s Day, the Copernicus Sentinel-2 mission takes us over Valentine Island in northern Western Australia.www.esa.int
A new study shows that extreme black holes could break the famous "no-hair" theorem, and in a way that we could detect.www.quantamagazine.org
New research lends credence to the account of Sir Thomas More.arstechnica.com
A commonly used asthma treatment appears to reduce the need for hospitalizations as well as recovery time for COVID-19 patients if given within seven days of symptoms appearing, researchers at the University of Oxford said on Tuesday.#science #medicine #health #Covid-19 #CoronaVirus #pandemic
The findings were made following a mid-stage study of the steroid budesonide, sold as Pulmicort by AstraZeneca Plc and also used for treating smoker’s lung.
A commonly used asthma treatment appears to reduce the need for hospitalizations as well as recovery time for COVID-19 patients if given within seven days of symptoms appearing, researchers at the University of Oxford said on Tuesday.www.reuters.com
The Emirates Mars Mission aims to provide a complete picture of the Martian atmosphere for the first time. Women make up 80% of the program's scientific team.m.dw.com
All n all. I spent around 5 days chasing this bug through my code. I generated Gigabytes of log files and had to get down to the precision of 7.5 grains of sand on the planet Earth. The compiler missing a key function call turned out to be the cause of the issue. Many times, while trying to find the root cause I found myself questioning my ability to write code, diagnose bugs and remain sane. I’m glad I found an answer and have a way forward.#programming #science compiler
It began as a whim: talk to a physicist, $50 per 20 minutes. But those ‘crackpots’ taught me something about my subjectaeon.co