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Studies have shown that pollution, whether from factories or traffic-snarled roads, disproportionately affects communities where economicall...

Sunday, February 28, 2021

Slime mold doesn't have a brain, but it can 'remember' where to find food

It may be a single-celled organism, but the slime mould Physarum polycephalum has some pretty fascinating tricks up its pretty yellow sleeves. Now new research has found that it seems to "remember" where it previously found sources of food - even without a brain or nervous system.


This could help explain how network organisms can not just live, but thrive, in complex environments, the researchers said - and could also be a key to understanding the mechanisms of memory formation in such species.


P. polycephalum is one of the most peculiar forms of life on Earth. It is neither plant, animal, or fungus, but a species of complex, single-celled amoeba of the protist kingdom (sort of the catch-all group for anything that can't be neatly categorized in the other three kingdoms).


Early in its life cycle, P. polycephalum exists as a single cell with a single nucleus, but later it merges with other cells to form a huge single cell with millions of nuclei inside.


This is the plasmodium stage, and the organism can grow to cover an area up to several square meters. Its body consists of a complex network of interconnected tubes, the squeezing of which creates flow between different regions. This network can rapidly grow and reorganize itself to maximize its use of its environment.


physarum bodyA Physarum plasmodium. (Carolina Biological Supply Company/Flickr/CC BY-NC-ND 2.0)


In 2000, Japanese researcher Toshiyuki Nakagaki of RIKEN discovered that P. polycephalum was capable of solving a simple maze to reach a food source. Since then, scientists have discovered several intelligent-like behaviors, like being able to efficiently solve the Traveling Salesman Problem, and 'remembering' substances.


In its latest trick, biological physicists Mirna Kramar and Karen Alim of the Max Planck Institute for Dynamics and Self-Organization in Germany have discovered, P. polycephalum uses the very architecture of its body to store memories about where it has previously found food.







"We followed the migration and feeding process of the organism and observed a distinct imprint of a food source on the pattern of thicker and thinner tubes of the network long after feeding," Alim explained.


"Given P. polycephalum's highly dynamic network reorganization, the persistence of this imprint sparked the idea that the network architecture itself could serve as memory of the past. However, we first needed to explain the mechanism behind the imprint formation."


Using microscopic observations, they made a careful study of how the organism arranged itself around a food source. They then used theoretical modeling to understand what was going on inside the slime mould during that process.


They concluded that the discovery of a source of food triggers the release of a chemical that locally softens the tube wall at the site of the food. This then triggers the tubes to dilate, becoming wider, to expedite flow within the slime mould to the site.


The chemical also signals to the entire organism where the food can be found, so that it can move towards the site and focus on feeding.







P. polycephalum can reabsorb parts of its body if it stretches out exploratory tubes into a region that is inhospitable, or contains nothing of interest. But when it has found and eaten a nutritious meal, those thick tubes remain in place so that it can quickly return to the site if food were to reappear, the researchers found.


"The gradual softening is where the existing imprints of previous food sources come into play and where information is stored and retrieved," Kramar said.


"Past feeding events are embedded in the hierarchy of tube diameters, specifically in the arrangement of thick and thin tubes in the network. For the softening chemical that is now transported, the thick tubes in the network act as highways in traffic networks, enabling quick transport across the whole organism. Previous encounters imprinted in the network architecture weigh into the decision about the future direction of migration."


This is not utterly dissimilar to how the human brain works. One must be cautious drawing parallels between slime mould and the human brain, but there are some interesting similarities that might be able to help us understand how information encoding works in various types of organisms.


In this case, synapses, which send information between neurons, strengthen when we learn and grow stronger the more we use them, but can grow weaker if we don't - vaguely similar to the slime mould's tubes, which will grow thicker at sites of interest, but will die off or be reabsorbed if their presence is no longer useful to the organism.


"It is remarkable that the organism relies on such a simple mechanism and yet controls it in such a fine-tuned way," Alim said.


"These results present an important piece of the puzzle in understanding the behavior of this ancient organism and at the same time point to universal principles underlying behavior. We envision potential applications of our findings in designing smart materials and building soft robots that navigate through complex environments."


The research has been published in PNAS.





#Nature | https://sciencespies.com/nature/slime-mold-doesnt-have-a-brain-but-it-can-remember-where-to-find-food/

6 Weird Ways People Tried To Cure The 1918 Influenza


It’s almost impossible to avoid comparing the Covid-19 pandemic to the pandemics of the past, especially the bubonic plague and the 1918 flu pandemic. But it turns out that a century of medical knowledge, along with drastic improvements in food and drug regulations, make a huge difference in how we face off against a deadly pathogen. If you’d like a few examples, here’s how people tried to fend off the 1918 influenza.


Camphor Oil


Camphor is a waxy, strong-smelling stuff that’s found in the wood of the camphor laurel; you can also produce it from turpentine, which is distilled pine resin. During the 1918 flu pandemic, camphor was a popular ingredient in over-the-counter medicines. One Wisconsin doctor went as far as injecting it directly into a patient’s arms and legs in hopes of controlling his fever.


It turns out that camphor does help kill some bacteria and viruses, soothe coughs, and ease pain when applied to the skin. But, as a 2013 paper warns, “However, camphor is a very toxic substance and numerous cases of camphor poisoning have been documented.”



Beef Gravy


An ad for Oxo beef gravy claimed that “a cupful of Oxo two or three times a day will prove an immense service as a protective measure,” allegedly because well-nourished people were less likely to get sick. “It increases nutrition and maintains vitality in the system, and thus an effective resistance is established against the attacks of the influenza organism.”


Laxatives


The Oshkosh Daily Northwestern ran a recurring article advising people to "Go to bed and stay quiet—take a laxative—eat plenty of nourishing food—keep up your strength—-nature is the 'cure.' Always call a doctor." Another remedy, published a few years later, recommended “keeping the bowels open” with Epsom salts while the patient drank hot lemonade and enjoyed a hot mustard foot bath, along with quinine.


MORE FOR YOU


Liquor


Many people turned to alcohol as a preventive or a cure. According to a CDC oral history of the pandemic, “During the great flu pandemic of 1918, there was a county doctor who boasted that he had never lost a patient. His secret weapon was ‘rotgut’ whiskey. He would pour the whiskey into a patient to get them to cough up the phlegm. During the pandemic, he ran out of whiskey and there was none to be had in the community. The only whiskey in Lusk was locked–up in the sheriff′s office as evidence for a bootlegger′s trial. The sheriff refused to release the liquor. So, the doctor got a few prominent citizens together for a kind of vigilante committee that promptly seized the whiskey, depriving the sheriff of his evidence.”


Elsewhere, dry cities and counties around the country (the pandemic struck just two years before the onside of nationwide prohibition) made exceptions for medicinal use, and the major of Burlington, Vermont even opened a dispensary.


Onions


In the archives of the National World War I Museum and Memorial, you can find an original recipe for an onion soup that supposedly helped prevent the Spanish Flu (spoiler alert: it probably doesn’t prevent anything except a continued craving for onion soup). For centuries, people in Europe credited fresh-cut onions with the ability to fight off disease by pulling the germs right out of the air. The idea started with bubonic plague in the 1500s and continued through the flu pandemic at turn of the 20th century. But even the National Onion Association, which arguably has a vested interest in promoting onion use, says onions won’t save you from contagious disease: “There is no scientific evidence that a cut raw onion absorbs germs or rids the air of toxins/poisons.”


Snake Oil And More


During the 1918 flu pandemic, snake oil salesmen did a booming business. That’s a literal statement; some newspapers carried ads for actual snake oil, supposedly made from the rendered fat of snakes (although labelling requirements were basically nonexistent, so a lot of alleged snake oil contained no snake-based ingredients at all). It’s also a figurative statement, as so-called “patent medicines” with names like Dr. Pasteur’s Microbe Killer, Kraft Preventative Powder, Father John’s Medicine, and Gude's Pepto-Mangan. Most of these products contained little or no actual medicine, had never been through clinical trials, and in some cases they were actually harmful even to healthy people.







#News | https://sciencespies.com/news/6-weird-ways-people-tried-to-cure-the-1918-influenza/

Maxar remains focused on multiyear diversification strategy

SAN FRANCISCO — Maxar Technologies is continuing to diversify its business but remains in the “early innings” in attracting more defense and intelligence work, said Dan Jablonsky, Maxar president and CEO.


“It’s a multiyear journey that we’re on,” Jablonsky said Feb. 24 during a company earnings call. “We do expect to gain programs over time and we’ve been upgrading our talent to be able to tackle this.”


Since taking the helm of Maxar in 2019, one of Jablonsky’s goals has been to diversify revenues to derive about a third from commercial, a third from civil government and a third from military and intelligence contracts.


Maxar has steadily expanded its civil business, largely by winning NASA science and exploration contracts, including the lunar Gateway Power and Propulsion Element.


Another Maxar priority is winning Earth-intelligence contracts and ensuring the business is headed “for sustained growth moving forward,” Jablonsky said.


“This means we’ll be focused on launching the WorldView Legion constellation, successfully competing for the next iteration of the EnhancedView program and continuing to make investments in 3D, artificial intelligence and machine learning,” Jablonsky said.


Maxar’s analytics business is currently growing more rapidly than its imagery business. When Maxar’s WorldView Legion constellation comes online, imagery sales are likely to outpace analytics.


“We’re capacity constrained,” Dan Jablonsky, Maxar president and CEO, said Feb. 24 during a company earnings call. “Toward the end of the year, that flips into a lot of capacity.”


Maxar plans to launch its first two Worldview Legion satellites in September and four additional WorldView Legion satellites about three to six months later. WorldView Legion satellites are scheduled to launch on SpaceX Falcon 9 rockets.


As the company expands its civil and defense business, Maxar continues to manufacture geostationary communications satellites, a business Jablonsky expects to remain fairly level.


“We’ll be looking to get our fair share of those awards,” Jablonsky said. “There are some low-Earth orbit opportunities out there.”


For the fourth quarter ended Dec. 31, Maxar revenues from continuing operations increased to $467 million from $410 million a year earlier. Revenues for the year rose to $1.7 billion from $1.67 billion for 2019.


In the fourth quarter, Maxar reported a net loss from continuing operations of $52 million, compared with net income of $53 million for the last three months of 2019. “The decrease was primarily driven by a gain on sale of assets of $136 million in 2019 that did not reoccur in 2020,” which was partially offset by increased revenues from the firm’s Space Infrastructure business, according to a Maxar news release.


For 2020 as a whole, Maxar reported a net loss of $46 million. Maxar reported net income of $83 million for 2019.


“The decrease was primarily driven by the receipt of satellite insurance proceeds of $183 million and a gain on sale of assets of $136 million in 2019 that did not reoccur in 2020,” according to the news release.


Maxar provided some information on the Sirius XM-7 satellite failure reported to the U.S. Securities and Exchange Commission on Jan. 27 by Sirius XM Holdings.


As of Dec. 31, the satellite launched Dec. 13 “was functioning as intended,” Maxar said in its annual 10-K report.


“There is an evaluation underway to determine the extent of damage to its SXM-7 satellite caused by certain events on January 16, 2021,” the Maxar 10-K said.


During the earnings call, Jablonsky said, “We don’t have anything to report on the continued troubleshooting work we’re doing with the satellite and with the customer.”









#Space | https://sciencespies.com/space/maxar-remains-focused-on-multiyear-diversification-strategy/

Scientists find 140,000 virus species in the human gut, and most are unknown


The coronavirus pandemic has had the world fixated on viruses like no time in living memory, but new evidence reveals humans never even notice the vast extent of viral existence – even when it's inside us.


A new database project compiled by scientists has identified over 140,000 viral species that dwell in the human gut – a giant catalogue that's all the more stunning given over half of these viruses were previously unknown to science.


If tens of thousands of newly discovered viruses sounds like an alarming development, that's completely understandable. But we shouldn't misinterpret what these viruses within us actually represent, researchers say.


"It's important to remember that not all viruses are harmful, but represent an integral component of the gut ecosystem," explains biochemist Alexandre Almeida from the European Molecular Biology Laboratory's Bioinformatics Institute (EMBL-EBI) and the Wellcome Sanger Institute.


"These samples came mainly from healthy individuals who didn't share any specific diseases."


The new virus catalogue – called the Gut Phage Database (GPD) – was complied by analyzing over 28,000 individual metagenomes – publicly available records of DNA-sequencing of gut microbiome samples collected from 28 countries – along with almost 2,900 reference genomes of cultured gut bacteria.


The results revealed 142,809 viral species that reside in the human gut, constituting a specific kind of virus known as a bacteriophage, which infects bacteria, in addition to single-celled organisms called archaea.







In the mysterious environment of the gut microbiome – inhabited by a diverse mixture of microscopic organisms, encompassing both bacteria and viruses – bacteriophages are thought to play an important role, regulating both bacteria and the health of the human gut itself.


"Bacteriophages … profoundly influence microbial communities by functioning as vectors of horizontal gene transfer, encoding accessory functions of benefit to host bacterial species, and promoting dynamic co-evolutionary interactions," the researchers write in their new paper.


For a long time, our knowledge of this phenomenon was stalled by limitations in our understanding of bacteriophage species.


In recent years, new advancements in metagenomic analyses have significantly expanded our awareness of the viral variety we're looking at here – and perhaps none more so than the Gut Phage Database, which the researchers describe as a "massive expansion of human gut bacteriophage diversity".


"To our knowledge, this set represents the most comprehensive and complete collection of human gut phage genomes to date," the study authors write.


"Having a comprehensive database of high-quality phage genomes paves the way for a multitude of analyses of the human gut virome at a greatly improved resolution, enabling the association of specific viral clades with distinct microbiome phenotypes."







Already, the database is updating what we know about viral behavior.


The research shows over one-third (36 percent) of viral clusters identified are not restricted to infecting a single species of bacteria, which means they can create gene flow networks across phylogenetically distinct bacterial species.


In addition, the researchers found 280 globally distributed viral clusters, including one newly identified clade, called Gubaphage, which appears to be the second most prevalent virus clade in the human gut, following what is known as the crAssphage group.


Given certain similarities between the two, the researchers initially thought the Gubaphage might belong to a proposed family of crAssphage-like viruses, before determining the clades were, in fact, distinct.


There is still so much to learn, and not just on the Gubaphage – but about more multitudes of viruses than we ever dared to dream. Thanks to research efforts like this, though, tomorrow's discoveries are closer, and new insights will come faster.


"Bacteriophage research is currently experiencing a renaissance," says microbiologist Trevor Lawley from the Wellcome Sanger Institute.


"This high-quality, large-scale catalogue of human gut viruses comes at the right time to serve as a blueprint to guide ecological and evolutionary analysis in future virome studies."


The findings are reported in Cell.





#Nature | https://sciencespies.com/nature/scientists-find-140000-virus-species-in-the-human-gut-and-most-are-unknown/

America's First Black Physician Sought to Heal a Nation's Persistent Illness

James McCune Smith was not just any physician. He was the first African American to earn a medical degree, educated at the University of Glasgow in the 1830s, when no American university would admit him. For this groundbreaking achievement alone, Smith warrants greater appreciation.



















But Smith was also one of the nation’s leading abolitionists. In 1859, Frederick Douglass declared, “No man in this country more thoroughly understands the whole struggle between freedom and slavery than does Dr. Smith, and his heart is as broad as his understanding.” A prolific writer, Smith was not only the first African American to publish peer-reviewed articles in medical journals; he also wrote essays and gave lectures refuting pseudoscientific claims of black inferiority and forecast the transformational impact African Americans were destined to make on world culture.








John Stauffer, a Harvard English professor who edited The Works of James McCune Smith, says that Smith is one of the underappreciated literary lights of the 19th century, calling him “one of the best-read people that I’ve encountered.”








“The closest equivalent I really can say about [him] as a writer is [Herman] Melville,” adds Stauffer. “The subtlety and the intricacy and the nuance…and what he reveals about life and culture and society are truly extraordinary. Every sentence contains a huge amount.”








Smith was born enslaved in New York City, in 1813, to Lavinia Smith, a woman born in Charleston, South Carolina, who historians believe was brought to New York in bondage. While James McCune Smith never knew his father, a white man, university records indicate he was a merchant named Samuel Smith. (Amy Cools, a University of Edinburgh scholar who has conducted the most extensive research into Smith’s paternity, maintains, however, “Meticulous research has thus far failed to yield any records of [such] a Samuel Smith…indicating the name “Samuel” may possibly have been entered into [the] university records for convenience or respectability’s sake.”). Smith received his primary education at the African Free School #2 on Lower Manhattan’s Mulberry Street, an institution founded in 1787 by governing New York elites. Their aim was to prepare free and enslaved blacks “to the end that they may become good and useful Citizens of the State,” once the state granted full emancipation.








The school graduated a roster of boys who would fill the upper ranks of black intellectual and public life. Smith’s cohort alone included Ira Aldridge, the Shakespearean tragedian and first black actor to play Othello on the London stage; the abolitionist minister Henry Highland Garnet, the first African American to address Congress; Alexander Crummell, an early pan-Africanist minister and inspiration to W.E.B. DuBois; and brothers Charles and Patrick Reason, the first African American to teach at a largely white college and a renowned illustrator-engraver, respectively. These men’s achievements would be exceptional by any standard, but even more so, for a group who were born enslaved or deprived basic rights as free blacks.








They were also all leading abolitionists, contributing their varied talents to the cause. University of Connecticut literature professor Anna Mae Duane, who tells the intertwined life stories of Smith and his classmate Garnet in her book Educated for Freedom, says the boys at the African Free School spurred each other on to great success and that the school’s innovative method of teaching contributed to that. The schoolmaster, a white Englishman named Charles C. Andrews, brought with him from his home country the Lancasterian system to help one or a handful of teachers instruct a class of 500 boys. “The boys would teach other,” Duane says. “They were all deputized as assistant teachers, basically.” This had a galvanizing effect on their confidence.








“When you are learning something, you are learning from another black person,” Duane says. “There was so much they did for each other because of way the school was run. It gave this incredible sense of authority and community.” Just as they elevated each other, the boys were destined to do the same for their people. Garnet formed a club of among the boys, Duane says, and the boys took an oath to “get their education and free everyone down south.”








Even among this exceptional group, Smith stood out as the school’s star pupil. In 1824, the school selected him to address the Marquis de Lafayette when the abolitionist Revolutionary War hero visited the school during his farewell tour of America. Freed by New York’s Emancipation Act of 1827, and after graduating the African Free School at 15, with honors, the next year, Smith apprenticed to a blacksmith, while continuing his studies with area ministers.








He took instruction in Latin and Greek from his mentor, the Reverend Peter Williams, Jr., another African Free School alum, and the pastor of St. Philip’s Church, the leading black church in the city. Garnet recalls his friend working “at a forge with a bellows in one hand and a Latin grammar in the other.” In time, Smith would master French, and demonstrate proficiency in Spanish, German, Italian and Hebrew.








When Columbia University and Geneva College (now Hobart and William Smith Colleges in New York) refused Smith admission because of his race, Smith’s benefactors raised funds so he could attend the University of Glasgow, which Stauffer describes as “a deeply abolitionist university at the time,” with ties to the abolitionist movement in New York. “Glasgow was a far better university than any American college at the time,” Stauffer said, and “on par with Oxford and Cambridge.” The university had been the seat of the Scottish Enlightenment just decades earlier, and had graduated pioneering thinkers including Adam Smith and James Watt.








At Glasgow, Smith was a charter member of in the Glasgow Emancipation Society, joining just before Britain abolished slavery in 1833. In a span of five years, he earned his bachelors, masters,’ and medical degrees, graduating at or near top of his class. Then, he completed his residency in Paris. The African American press heralded his return to the U.S. in 1837.








In New York, Smith established his medical practice at 55 West Broadway, where he also opened the first black-owned pharmacy in the United States. He saw both black and white patients, men and women. “[Whites] were willing to go to him because of his reputation,” Stauffer says. “He was widely recognized as one of the leading medical doctors in New York.…Even white doctors who were racists couldn’t help [but respect his expertise] because of his publications.” In 1840, Smith authored the first medical case report by an African American, titled, “Case of ptyalism with fatal termination,” but was denied the opportunity to present this paper on fatal tongue-swelling to the New York Medical and Surgical Society, “lest it might interfere with the ‘harmony’ of the young institution,” the society insisted. His paper, “On the Influence of Opium upon the Catamenial Functions,” was the first publication by an African American in a peer-reviewed medical journal.








While the foregoing represents Smith’s contributions to conventional medical research and treatment (and concerned mostly white patients), Smith dedicated considerable attention to challenging pseudoscientific justifications for African American oppression. The moment he stepped back on U.S. soil, he delivered a lecture titled “The Fallacy of Phrenology,” where he attacked the notion that head shape and size dictates the relative intelligence of different racial groups.








Having embraced at Glasgow Adolphe Quetelet’s pioneering application of statistics to social science, Smith frequently marshaled sophisticated statistical analysis to make his case. When the federal government used data from the 1840 census to argue that emancipated blacks in the North, when compared to those still enslaved, were “more prone to vice and pauperism, accompanied by the bodily and mental inflictions incident thereto—deafness, blindness, insanity and idiocy,” Smith mounted a campaign to refute the claim.








The Harvard-trained physician Edward Jarvis, who had initially supported these government findings, later joined Smith in exposing fundamental errors in the census. For example, Smith demonstrated that the census often tallied more infirm or “insane” black persons than there were black persons in a given state (“to make 19 crazy men out of one man”). More fundamentally, he showed the census failed to account for the higher mortality rate among the enslaved population—the murder of blacks, he charged, at young ages. In an 1844 letter to the New York Herald on the topic, he writes, “What mockery it is for men to talk of the kindness of masters in taking care of aged slaves, when Death has relieved them of so large a share of the burden!”








Smith served for 20 years as the medical director of the Colored Orphan Asylum, a position he assumed some years after he accused the asylum’s previous doctor of negligence for concluding that the deaths among his charges were due to the “peculiar constitution and condition of the colored race.” Smith made great improvements in the medical care at the institution, containing outbreaks of contagious diseases by expanding the medical ward to allow for greater separation and isolation of sick children. He saw the Quaker-run institution as one of the best schools in the city for black children, providing for them what the African Free School provided for him, with a critical difference: Duane says the philosophy of the African Free School was, “You need to admire a version of history that disconnects you from the history of slavery in this country…your own mother… You’re not orphaned but you orphan yourself. You leave the past behind.”








The leaders of the African Free School contemplated the children would educate themselves, gain freedom and repatriate to Africa. By contrast, Smith, says Duane, “saw education [at the orphanage] as a way of supporting families, of putting down roots in the U.S. And fighting for citizenship.”








He also knew an educated black population marked the beginning of the end of slavery. Slavery, Stauffer says, relies on a “totalitarian state” where no one is permitted to question the status quo. So, in the case of enslaved persons like Smith and his cohort who become free, he says, “That’s when they start speaking and writing profusely, and that’s what really fuels or creates the abolition movement.” Education and freedom of expression is anathema to slavery. “All slave societies do their best to prevent slaves from having a public voice, because if they do it’s going to wreak havoc on the society.”








Havoc was necessary if abolition could not be achieved by other means. Smith defied the 1850 Fugitive Slave Act, which required that citizens in free States aid in the recapture of persons fleeing bondage, as he met with other black activists in the back room of his pharmacy to arrange for the protection of runaways. In 1855, he co-founded the interracial Radical Abolitionist Party, with Frederick Douglass, former Congressman Gerrit Smith, and John Brown, the abolitionist man-in-the-arena, who in 1859 would lead a foiled attack on the federal armory at Harper’s Ferry, Virginia, in an attempt to instigate a revolt among the area’s enslaved population. The party advocated a pluralistic, egalitarian society, for men and women of all backgrounds.








Unlike William Lloyd Garrison advocated “moral suasion” as the means to rid the nation of slavery, these radical abolitionists were prepared to use violence if it would liberate their brethren from bondage. Smith reasoned in an 1856 essay in Frederick Douglass’ Paper, “Our white brethren cannot understand us unless we speak to them in their own language; they recognize only the philosophy of force. They will never recognize our manhood until we knock them down a time or two; they will then hug us as men and brethren.”








Smith predicted the institution of slavery would not give up the ghost on its own. “African Americans recognized that violence is at the heart of slavery,” Stauffer says. “Without violence, slavery cannot exist…And so, [African Americans] were practical.”








In general, Smith and the Radical Abolitionist Party believed that white Americans needed to embrace African-American perspectives in order to see America in its true light and redeem it. He wrote, “[W]e are destined to spread over our common country the holy influences of principles, the glorious light of Truth.” This access to truth, he predicted, would be manifested in African American oratory, poetry, literature, music and art. Stauffer says that one of Smith’s lifelong interests was to reveal to people the unrecognized influence of Africans and African Americans in the advance of scholarship and culture. An 1843 publication records Smith proclaiming in an 1841 lecture:









“For we are destined to write the literature of this republic, which is still, in letters, a mere province of Great Britain. We have already, even from the depths of slavery, furnished the only music this country has yet produced. We are also destined to write the poetry of the nation; for as real poetry gushes forth from minds embued with a lofty perception of the truth, so our faculties, enlarged in the intellectual struggle for liberty, will necessarily become fired with glimpses at the glorious and the true, and will weave their inspiration into song.”









Indeed, as Smith observed, songs among the enslaved were already shaping American music in his time. “Sometimes I Feel Like a Motherless Child,” a haunting spiritual about the separation of children from their mothers during slavery, would later, as musicologists acknowledge, form the basis for George Gershwin’s 1934 song, “Summertime.”








Smith himself made significant contributions to the American literary canon with a series of narrative sketches in Frederick Douglass’ Paper, which he called, “The Heads of Colored People.” With its title mocking the attempts of phrenology to diminish the worth of African Americans, Smith paints dignified portraits of everyday black people—a bootblack, a washerman—as examples of the unique personalities inherent to every human being.








Smith died in November 1865 of congestive heart failure, living his final years in Williamsburg, Brooklyn. He and many black families fled Manhattan after the 1863 Draft Riots, where largely working-class Irish draft resisters assaulted and killed black New Yorkers and attacked charitable institutions associated with African-Americans and the war. Most distressing for Smith were these events of July 13 of that year, as reported by the New York Times:








“The Orphan Asylum for Colored Children was visited by the mob about 4 o'clock. … Hundreds, and perhaps thousands of the rioters, the majority of whom were women and children, entered the premises, and in the most excited and violent manner they ransacked and plundered the building from cellar to garret.”








The rioters burned the building to the ground. Fortunately, the staff managed to escort all the children to safety through a back exit. An ailing Smith was not at the asylum that day, and despite attacks in the vicinity of his home and pharmacy was not harmed. But he and other black New Yorkers were shaken. The mob ultimately killed an estimated 175 people, including many who were hanged or burned alive. It’s estimated that in the riot’s aftermath, Manhattan’s black population declined by 20 percent, many departing for Brooklyn.








“I didn’t know he was my ancestor,” says Greta Blau, a white woman who learned about Smith when she wrote a paper on the Colored Orphan Asylum for a class at Hunter College in the 1990s. While she had seen his name in her grandmother’s family Bible, he was a “Scottish doctor” in family lore. Only later did she make the connection. “I think all his children “passed,” she said, meaning that Smith’s descendants hid their black ancestry in order to enjoy the privileges of whites in a segregated world. The 1870 U.S. census recorded Smith’s children as white and they, in turn, married white spouses.








Knowledge of Smith’s achievements as an African American might have endured had he published books, but his essays from periodicals were more easily forgotten. Whereas Douglass was the most photographed American of the 19th century, only one portrait of Smith exists. Blau realizes why Smith’s children did not seek to keep his legacy alive: “In order for his children to be safe and pass, he had to be forgotten,…which is tragic.” In 2010, Blau arranged for the placement of a new headstone at Smith’s grave in Brooklyn’s Cypress Hill Cemetery.








Remarkably, several white descendants of Smith are interred in the same section established by St. Philip’s Church, the black church Smith attended. Blau’s grandmother, who died in 2019 at 99 years old, joined her for the ceremony at the gravesite, as did descendants from Smith’s other children, whom Blau first met when she contacted them to share the news of their ancestor. While other descendants she contacted did not welcome the news of her discovery, these distant cousins who joined her for the ceremony made the journey from the Midwest to be there. “They were proud of it. Just proud.”














#History | https://sciencespies.com/history/americas-first-black-physician-sought-to-heal-a-nations-persistent-illness/

Indian PSLV rocket launches Brazilian Amazonia-1 satellite

HELSINKI — India launched its first mission of the year late Saturday, sending Brazil’s Amazonia-1 Earth observation satellite and 18 smaller payloads into orbit.


The 44-meter-high PSLV-C51 rocket with two solid side boosters lifted off from the Satish Dhawan Space Center on the Indian island of Sriharikota at 11:54 p.m. Eastern Feb. 28.


The  PSLV injected the roughly 700-kilogram Amazonia-1 into its intended Sun-synchronous orbit 17 minutes after launch. The further 18 passengers were released over the subsequent 98 minutes in accordance with a predetermined sequence.


The mission was hailed as the first dedicated commercial mission of NewSpace India Limited (NSIL), a Government of India company under the Department of Space. 


Optical Earth observation satellite Amazonia-1 belongs to Brazil’s National Institute for Space Research (INPE). Indian Space Research Organisation (ISRO) chairman K Sivan stated shortly after launch the satellite was in good health.


This satellite is designed to deliver remote sensing data to the government and science community for monitoring deforestation in the Amazon region and analysis of diversified agriculture across the Brazilian territory. 


It carries a wide-view optical imager (camera with 3 frequency bands in the visible spectrum – VIS – and 1 band near the infrared – Near Infrared) capable of observing a 850 km range with 64 meters of resolution.


Amazonia-1 is the first Earth observation satellite completely designed, integrated, tested and operated by Brazil. INPE plans to launch two further satellites in the series. INPE of Brazil contracted Spaceflight Inc. to secure the launch.


Its relatively low mass allowed margin for a number of other payloads. Of these 14 were aboard through NSIL, including 12 SpaceBEE 1U-CubeSats for U.S.-based Swarm Technologies, Inc. for two-satellite communications and data relay, and SAI-1 NanoConnect-2, developed by the Space Instrumentation Laboratory of the National University of Mexico. SindhuNetra, an AIS technology demonstrator, was funded by the Defense Research and Development Organization of India.


The four further payloads were for INSPACe, India’s new regulatory and space promotion organization. These were three UNITYsat satellites developed by the Jeppiaar Institute of Technology, G. H. Raisoni College of Engineering, and the Sri Shakthi Institute of Engineering and Technology. The final payload is the 3U-CubeSat Satish Dhawan Sat (SDSAT) from Space Kidz India to study radiation and the magnetosphere. 


ISRO stated that the total number of customer satellites from foreign countries placed in orbit by PSLV is 342 satellites from 34 countries following the PSLV-C51 launch.


The launch is India’s first of a 2021, following a 2020 severely impacted by the COVID-19 pandemic. Satish Dhawan Space Center carried out its first 2020 mission only in November with the launch of the EOS-1 Earth observation satellite and nine smaller payloads.


India is expected to launch a number of missions in the coming months including the GSLV launch of the country’s first geostationary Earth observation satellite, GISAT-1. The mission is one of a number delayed by the COVID-19 outbreak.


ISRO is targeting a first uncrewed test flight of a human-rated GSLV launcher for its Gaganyaan crewed program in December this year, but has conceded a first crewed flight will slip from August 2022 into 2023. 


Chandrayaan-3, a second attempt at setting a lander and rover on the moon, also slips from late 2021 into 2022.









#Space | https://sciencespies.com/space/indian-pslv-rocket-launches-brazilian-amazonia-1-satellite/

Orbex commissions 3D printer capable of producing 35+ rocket engines a year

VALETTA, Malta — On the heels of raising $24 million in December, Orbex announced Feb. 24 that it has commissioned AMCM to build a large-volume 3D printer for manufacturing its rocket engines. 


The Scottish microlauncher startup is currently developing Prime, a two-stage launch vehicle powered by six first-stage and one second-stage biopropane engines. The maiden flight of the vehicle is slated for 2022 from a proposed launch facility in Sutherland, Scotland.


Orbex said the 3D printer will be the largest in Europe, enabling the company to produce more than 35 rocket engines a year. Initially, however, the printer will be used to perfect its first- and second-stage engine designs.


“Although our rocket engines and other critical systems are already quite mature after years of testing, a large-scale in-house 3D printing system like this gives us far greater speed and agility as we ramp up production,” said Orbex CEO Chris Larmour. “It means we can continue to iterate and drive up performance even further.”


The 3D printer being created for Orbex is based on the four-laser AMCM M 4K-4 metal printing platform, which the German technology company began mass producing last June. A similar AMCM 3D printer has been utilized by U.S.-based microlaunch startup Launcher to produce test prototypes of its E-2 rocket engine.


In addition to the 3D printer itself, the multimillion dollar deal includes post-processing machinery and an automated imaging-based inspection system to validate the quality of prints.


To accommodate the 3D printer and its associated equipment, Orbex says it will expand the factory floor space of its development facility in Forres, Scotland by 1,000 square meters. 


The Orbex Forres facility was opened in 2019. The 2,000-square-meter facility includes a rocket design and integration facility, an operations centre and executive offices. Work on the expansion of the facility has already begun.


Orbex has secured customers for six Prime launches to date. The maiden launch of the vehicle is slated to carry an experimental payload for smallsat manufacturer Surrey Satellite Technology Ltd. Larmour said the company expected to announce additional customers in the next several months.









#Space | https://sciencespies.com/space/orbex-commissions-3d-printer-capable-of-producing-35-rocket-engines-a-year/

Scientists use weather radar tech to watch storms of microbes brew inside cells

Scientists are using a radar-like weather system to watch as a storm of pathogens brew inside living tissue.


The strategy is entirely novel, according to the authors, and relies on a technique very similar to Doppler radars, which can detect the motion of precipitation and predict upcoming weather patterns.


Doppler ultrasounds, which use sound waves to create images of blood flow, are already used in the medical sphere, but this new technique can allow scientists to peek inside individual cells to see how they respond to pathogens like salmonella and E. coli


Such knowledge could one day allow us to quickly figure out whether living tissue contains microbes or not and successfully treat that infection. 


In 2020, the team used similar biodynamic imaging to identify cancerous cells and test how effective chemotherapy truly is at beating them back.


"First we did biodynamic imaging applied to cancer, and now we're applying it to other kinds of cells," says David Nolte, who specialises in biomedical imaging at Purdue University.


"This research is unique. No one else is doing anything like it. That's why it's so intriguing."


Scattering light across living tissues results in a range of Doppler frequency shifts, which can tell scientists something about what is going on inside a living tissue's cells.


This Doppler 'fingerprint' as it is known is extremely sensitive to even subtle changes in intracellular processes, including bacterial invasion.







When bacteria infect a living host, it can alter the dynamics of the tissue's cells, allowing some to act as "sentinels", reporting on the pathogen's effects and its responses to antibiotic treatments.


These different frequency ranges can then be interpreted by scientists to better understand an infection's true character and how best to fight it.


To show how this technique works, researchers used a standard colon cancer cell line and introduced it to several food-borne pathogens to see how its first line of cells – the "sentinels" – responded to the different infections.


DopplerCellLineRadarPerdueThe Doppler machine used to look inside cells. (Rebecca McElhoe/Purdue University)


Invasive Salmonella was found to penetrate through the cancer tumours, while non-invasive strains of E. coli remained isolated outside the cells. Both scenarios ultimately generated different Doppler signatures.


"This directly measures whether a cell is pathogenic," says biological engineer Michael Ladisch.


"If the cells are not pathogenic, the Doppler signal doesn't change. If they are, the Doppler signal changes quite significantly." 


Using additional methods, researchers can figure out what pathogen is actually present within the living tissue. As Ladisch explains, it's "a quick way to tell friend from foe." 







Once that work is done, antibiotics can be applied to the cell line, and responses can be tracked using a fluorescent dye. Doppler shifts can then reveal which infections are resistant to drugs and which respond well to them.


Using current techniques, where a patient's tissues are cultured in the lab, it takes between 8 and 10 hours to figure out whether an antibiotic will work or not.


In roughly half that time, this new 'biodynamic process' can test multiple different medicines in tiny Petri dishes to see whether there have been any metabolic changes. 


Those samples that do show changes are the ones that have reacted well to the antibiotic, the authors say, meaning "the bacteria are dying, being defeated and beaten back by antibiotics."


"When we treat with antibiotics, the bacteria don't have to multiply much before they start to affect the tissue sentinels," explains Nolte. 


"There are still too few bacteria to see or to measure directly, but they start to affect how the tissues behaves, which we can detect with Doppler."


The authors hope their new technique will allow doctors to prescribe personalised antibiotics, instead of broad-spectrum ones, which can leave some bacteria living, cause antibiotic resistance and make the infection harder to fight in the future. 







The experiments were done outside normal biological context on artificially grown tissue, and because the equipment is sensitive to vibrations and movement, it's not clear whether this technique will translate to living and breathing patients.


That said, the authors hope they can figure out a way to counter their equipment's sensitivity, allowing infected tissue to be scanned on the outside of a patient's body and maybe even one day on the inside, too.


The study was published in Communications Biology





#Tech | https://sciencespies.com/tech/scientists-use-weather-radar-tech-to-watch-storms-of-microbes-brew-inside-cells/

Remnants of Tenth-Century Buddhist Monastery Found in India

Researchers with the Archaeological Survey of India (ASI) have discovered what appear to be the remains of a Buddhist monastery dated to the tenth century A.D.



















As Abhijit Sen reports for the Times of India, the archaeologists recently found 11 stone statues at the site, which is located in the Hazaribag district of the eastern Indian state of Jharkhand.








The sculptures each stand two to three feet tall. Six represent the Buddha, Siddhartha Gautama, while the other five likely depict Tara, who is known as a deity in Hinduism and a female bodhisattva—central figures who delay personal enlightenment in order to offer earthbound worshippers salvation—or Buddha in different Buddhist traditions.








Also recorded at the site were inscriptions in Devanagari script, which is used in languages including Sanskrit and Hindi. The team hopes that the writing, once translated, will provide more information about the monastery.








Per the Hindustan Times’ Sanjoy Dey, the ASI first discovered three mounds at the site—located in the foothills of Juljul Hill—last year. A team excavated one of the mounds and, after digging about six feet down, found a central shrine and two subsidiary shrines.








Since January, archaeologists have been working on a second mound about 130 feet away from the first. So far, they’ve found three cells in a nearly 27,000-square-foot space. The researchers say the site appears to be a small Buddha Vihar, or combination shrine and monastery.








“As per the evidence found here, it appeared that the structures had been built during the Pala period,” ASI archaeologist Neeraj Mishra tells the Hindustan Times.








Mishra notes that the site was located on the route of Grand Trunk Road, which connected Sarnath in Uttar Pradesh to Bodh Gaya, where Gautama reportedly attained enlightenment.








Artistic representations of Tara

Two other depictions of Tara

(Public domain / Brooklyn Museum via Wikimedia Commons)








D.N. Ojha, a historian at Ranchi University, tells the Hindustan Times that the discovery may help clarify the history of the arrival of Buddhist monks in the area and the overall spread of Buddhism. As Abhishek Angad reports for the Indian Express, the presence of Tara’s likeness suggests that the monastery served as an important center for the Vajrayana sect, a form of Tantric Buddhism.








The Pala Dynasty ruled the regions of Bengal and Bihar between the 8th and 11th centuries. It supported the establishment of Buddhist institutions, including monasteries, while also permitting the flourishing of Hinduism, the majority religion of the area. During the early Pala period, eastern Indian sculptors developed a regional style that paid detailed attention to textiles, jewelry and the human torso, per the Brooklyn Museum.








Earlier this year, archaeologists announced the discovery of the ruins of a Bihar monastery headed by a woman. Dated to the 11th or 12th century, the hilltop structure housed either all women or both women and men, as Jai Narain Pandey noted for the Times of India.








“Monasteries have been discovered at many locations in this area, but this is the first setup located at the top of a hill,” lead researcher Anil Kumar, an archaeologist at Visva Bharati University, told the Hindustan Times’ Reena Sopam in January. “Seems the Mahayani Buddhists set up the monastery far from the hustle and bustle of the human population to practice Mahayana rituals in isolation.”








According to the Times of India, the researchers at the Jharkhand site have removed the statues from the brick walls to which they were attached. They plan to ship the artifacts to ASI’s museum in Patna, Bihar.








Locals who have heard about the discovery, however, have proven eager to see the statues, and some are asking that the ASI set up a museum near the site to draw tourists to the area.














#History | https://sciencespies.com/history/remnants-of-tenth-century-buddhist-monastery-found-in-india/

NASA and Roscosmos leaders speak as plans finalized for flying astronaut on upcoming Soyuz flight

WASHINGTON — It is increasingly likely that a NASA astronaut will fly on a Russian Soyuz mission to the International Space Station in April as the agency finalizes an agreement with its Russian counterpart.


In a Feb. 25 statement, Roscosmos said that its director general Dmitry Rogozin, spoke that day with NASA Acting Administrator Steve Jurczyk. The conversation, Roscosmos stated, included congratulations from Rogozin on the landing last week of NASA’s Perseverance Mars rover and discussions of the upcoming launch of Russia’s Arktika-M satellite to monitor conditions in the Arctic.


The statement also mentioned “mutual content with the level of cooperation between Roscosmos and the US space agency including the International Space Station program” that appeared to include Soyuz flights. “The parties also touched upon the arrangement to maintain continuous presence of Russian and American crews at the ISS,” the readout said.


NASA announced Feb. 9 that it was working to obtain a seat on the next Soyuz mission to the ISS, Soyuz MS-18, scheduled for launch April 9. The agency said it would obtain the seat through the exchange of “in-kind services” rather than a direct purchase, an arrangement believed to involve a third party, commercial spaceflight company Axiom Space.


That announcement was tied to the publication of a “sources sought” procurement filing, a necessary step to identify any alternative arrangements before concluding the deal. The deadline for responding to the filing was Feb. 19.


NASA officials have said little publicly about its efforts to obtain the Soyuz seat, citing the ongoing procurement. “That’s an active procurement right now, and I’m just really not in a position where we can talk about it,” Kenny Todd, deputy manager of the ISS program at NASA, said during a Feb. 24 briefing about a pair of upcoming spacewalks at the station.


Todd declined to say even who NASA is considering to fly on that Soyuz seat, if it does obtain it. However, a Roscosmos press release Feb. 24 that discussed training by Russian cosmonauts for the upcoming mission appeared to confirm the identity of that astronaut.


In one image, cosmonauts Oleg Novitsky and Pyotr Dubrov were training in a simulator. Visible on their flight suits was the Soyuz MS-18 mission patch, which included their names along with “Vandei Hei,” an apparent reference to NASA astronaut Mark Vande Hei. He has been considered the most likely astronaut to fly the mission, given that he was the backup to Kate Rubins on the previous Soyuz mission to the station last October, alongside Novitsky and Dubrov. Vande Hei had also been seen in some photos in recent months training alongside Russian cosmonauts assigned to the prime and backup crews.


patch
The Soyuz MS-18 mission patch with the names of the crew, including Mark Vande Hei. Credit: Roscosmos

The Roscosmos statement did not mention Vande Hei, but also did not mention Sergey Korsakov, originally assigned to Soyuz MS-18. Rogozin told the Russian news agency TASS Feb. 24 that the upcoming Soyuz flight would have “an international crew,” but did not elaborate.


NASA officials have long talked about having “mixed crews” on both Soyuz and commercial crew missions to the ISS, with a NASA bartering seats on CST-100 Starliner and Crew Dragon spacecraft in exchange for seats on Soyuz spacecraft. Doing so would ensure at least one Russian and one American on the station at all times should one vehicle suffer problems that take it out of service for an extended period.


That exchange will ultimately be done through an agreement between NASA and Roscosmos, but NASA officials have said that would not be done in time for the April Soyuz mission. The process by which NASA, at nearly the last minute, is seeking to get a seat on the Soyuz launch has raised questions on Capitol Hill.


In a Feb. 23 letter to Jurczyk, Reps. Frank Lucas (R-Okla.) and Brian Babin (R-Texas), the ranking members of the full House Science Committee and its space subcommittee, respectively, asked for a briefing on NASA’s plans to obtain the Soyuz seat. “After spending billions of taxpayer dollars on developing capabilities to launch American astronauts on American rockets from American soil, it is important for Congress to understand NASA’s existing agreements and future plans for accessing the International Space Station,” they wrote.


NASA did not release its own readout of the call between Jurczyk and Rogozin, and the agency did not respond to a request for comment on the Russian statement.









#Space | https://sciencespies.com/space/nasa-and-roscosmos-leaders-speak-as-plans-finalized-for-flying-astronaut-on-upcoming-soyuz-flight/

Saturday, February 27, 2021

Recreated particles of Titan's haze could help us understand how life began on Earth

Beyond Earth, the general scientific consensus is that the best place to search for evidence of extraterrestrial life is Mars. However, it is by no means the only place.


Aside from the many extrasolar planets that have been designated as "potentially-habitable," there are plenty of other candidates right here in our Solar System.


These include the many icy satellites that are thought to have interior oceans that could harbor life.


Among them is Titan, Saturn's largest moon that has all kinds of organic chemistry taking place between its atmosphere and surface. For some time, scientists have suspected that the study of Titan's atmosphere could yield vital clues to the early stages of the evolution of life on Earth.


Thanks to new research led by tech-giant IBM, a team of researchers has managed to recreate atmospheric conditions on Titan in a laboratory.


Their research is described in a paper titled "Imaging Titan's Organic Haze at Atomic Scale," which recently appeared in the Feb. 12th issue of The Astrophysical Journal Letters.


The research team was led by Dr. Fabian Schulz and Dr. Julien Maillard and included many colleagues from IBM Research-Zurich, the University of Paris-Saclay, the University of Rouen at Mont-Saint-Aignan, and Fritz Haber Institute of the Max Planck Society.


PIA23172 1024x576Artist's concept of a lake on Saturn's moon Titan. (NASA/JPL-Caltech)


Much of what we know about Titan today is owed to the Cassini spacecraft, which orbited Saturn from 2004 to 2017 and finished its mission by diving into Saturn's atmosphere.


During this time, Cassini conducted many direct measurements of Titan's atmosphere, revealing a surprisingly Earth-like environment. Basically, Titan is the only other body in the Solar System that has a dense nitrogen atmosphere and organic processes taking place.







What is particularly interesting is the fact that scientists believe that roughly 2.8 billion years ago, Earth's atmosphere may have been similar. This coincides with the Mesoarchean Era, a period where photosynthetic cyanobacteria created the first reef systems and slowly converted Earth's atmospheric carbon dioxide to oxygen gas (eventually leading to its current balance of nitrogen and oxygen).


While the surface of Titan is believed to hold clues that could improve our understanding of how life emerged in our Solar System, getting a clear look at that surface has been a problem.


The reason for this has to do with Titan's atmosphere, which is permeated by a dense photochemical haze that scatters light. As Leo Gross and Nathalie Carrasco (co-authors on the study) explained in a recent article posted to the IBM Research Blog:



"Titan's haze consists of nanoparticles made of a wide variety of large and complex organic molecules containing carbon, hydrogen and nitrogen. These molecules form in a cascade of chemical reactions when (ultraviolet and cosmic) radiation hits the mix of methane, nitrogen and other gases in atmospheres like Titan's."








As a result, there is still much that scientists don't know about the processes that drive Titan's atmosphere, which includes the exact chemical structure of the large molecules that make up this haze.


For decades, astrochemists have been conducting laboratory experiments with similar organic molecules known as tholins – a term derived from the Greek word for "muddy" (or "hazy").


Tholins refer to a wide variety of organic carbon-containing compounds that form when exposed to solar UV or cosmic rays.


These molecules are common in the outer Solar System and are typically found in icy bodies, where the surface layer contains methane ice that is exposed to radiation. Their presence is indicated by surfaces that have a ruddy appearance, or like they have sepia-colored stains.


For the sake of their study, the team led by Schulz and Maillard conducted an experiment where they observed tholins in various stages of formation in a laboratory environment. As Gross and Carrasco explained:



"We flooded a stainless-steel vessel with a mixture of methane and nitrogen and then triggered chemical reactions through an electric discharge, thereby mimicking the conditions in Titan's atmosphere. We then analyzed over 100 resulting molecules composing Titan's tholins in our lab at Zurich, obtaining atomic resolution images of around a dozen of them with our home-built low-temperature atomic force microscope."



titan hazeNASA's Cassini spacecraft looks toward the night side of Saturn's largest moon. (NASA/JPL-Caltech/Space Science Institute)


By resolving molecules of different sizes, the team was provided with glimpses of the different stages through which these haze molecules grow, as well as what their chemical makeup looks like.


In essence, they observed a key component in Titan's atmosphere as it formed and accumulated to create Titan's famous hazy effect. Said Conor A. Nixon, a researcher with NASA's Goddard Space Flight Center (who was not affiliated with the study):



"This paper shows ground-breaking new work in the use of atomic-scale microscopy to investigate the structures of complex, multi-ringed organic molecules. Typical analysis of laboratory-generated compounds using techniques such as mass spectroscopy reveals the relative proportions of the various elements, but not the chemical bonding and structure.


"For this first time here we see the molecular architecture of synthetic compounds similar to those thought to cause the orange haze of Titan's atmosphere. This application now provides an exciting new tool for sample analysis of astrobiological materials, including meteorites and returned samples from planetary bodies."








What's more, their results may also shed light on Titan's mysterious methane-based hydrological cycle. On Earth, this cycle consists of water transitioning between a gaseous state (water vapor) and a liquid state (rain and surface water).


On Titan, the same cycle takes place with methane, which transitions from atmospheric methane gas and falls as methane rain to form Titan's famous hydrocarbon lakes.


In this case, the research team's results could reveal the role that the chemical haze plays in Titan's methane cycle, including whether or not these nanoparticles can float on its methane lakes.


Furthermore, these findings could reveal whether or not similar atmospheric aerosols helped life emerge on Earth billions of years ago.


"The molecular structures we have now imaged are known to be good absorbers of ultraviolet light," described Gross and Carrasco. "That, in turn, means that the haze may have acted as a shield protecting DNA molecules on the early Earth's surface from damaging radiation."


The PAMPRE device that recreated Titan's haze particles.The PAMPRE device that recreated Titan's haze particles. (Nathalie Carrasco/Flickr/CC BY-ND 2.0)


If this theory is correct, the team's findings would not only help scientists to understand the conditions under which life emerged here on Earth, and they could also point towards the possible existence of life on Titan.


The mysterious nature of this satellite is something scientists first became aware of in the early 1980s, when the Voyager 1 and 2 space probes both flew through the Saturn system. Since then, scientists have pieced together.


By the 2030s, NASA plans to send a robotic rotorcraft called Dragonfly to Titan to explore its surface and atmosphere and search for possible signs of life.


As always, the theoretical work and laboratory experiments performed in the meantime will allow scientists to narrow the focus and increase the odds that the mission (once it arrives) will find what it's looking for.


This article was originally published by Universe Today. Read the original article.





#Space | https://sciencespies.com/space/recreated-particles-of-titans-haze-could-help-us-understand-how-life-began-on-earth/

Ancient Roman chariot used in parades unearthed 'almost intact' near Pompeii

An ornate Roman chariot has been discovered "almost intact" near Italy's buried city of Pompeii, the archaeological park announced on Saturday, calling it a discovery with "no parallel" in the country.


The four-wheeled processional carriage was found in the portico to stables where the remains of three horses were unearthed in 2018, including one still in its harness.


Pompeii was buried in boiling lava when Mount Vesuvius erupted in 79 CE, killing between 2,000 and 15,000 people.


"A large ceremonial chariot with four wheels, along with its iron components, beautiful bronze and tin decorations, mineralised wood remains and imprints of organic materials (from the ropes to the remains of floral decoration), has been discovered almost intact," a statement issued by the archaeological park said.


"This is an exceptional discovery... which has no parallel in Italy thus far – in an excellent state of preservation."


RomanChariotPompeiiSideView(Pompeii Archaeological Park/AFP)


The excavation site is known as the Civita Giuliana, a suburban villa that lies just a few hundred metres from the ancient city of Pompeii.


The excavation is part of a programme aimed at fighting illegal activity in the area, including tunnel digging to reach artefacts that can be sold on illicit markets.


Looters missed the room where the chariot had lain for almost 2,000 years, tunnelling by on both sides, the park's statement said.







Specialists took great care to unearth the vehicle, for example by pouring plaster into voids "to preserve the imprint of any organic material" that had decomposed, it added. 


The park said this had allowed it to emerge well preserved down to the imprints of ropes, "thus revealing the chariot in all of its complexity".


"Pompeii continues to amaze with all of its discoveries, and it will continue to do so for many years yet, with 20 hectares (50 acres) still to be excavated," Culture Minister Dario Franceschini was quoted as saying.


'Parades and processions'


"It is an extraordinary discovery for the advancement of our knowledge of the ancient world," added Massimo Osanna, outgoing director of the park.


"What we have is a ceremonial chariot, probably the Pilentum referred to by some sources, which was employed not for everyday use or for agricultural transport, but to accompany community festivities, parades and processions."




Pompeii's remarkably well-preserved remains have slowly been uncovered by teams of archaeological specialists.


It is Italy's third most visited tourist site, drawing more than 3.9 million visitors in 2019.


The ancient city was closed after the coronavirus struck, and only reopened on January 18.


© Agence France-Presse





#Humans | https://sciencespies.com/humans/ancient-roman-chariot-used-in-parades-unearthed-almost-intact-near-pompeii/

Why the Covid-19 Vaccine Rollout Will Be Different for Kids


Around the country, the Covid-19 vaccine rollout is expanding from healthcare workers and people who live in long-term care facilities to older adults, essential workers and people with chronic medical conditions, depending on location.



















Two vaccines have been authorized so far—one created by Moderna is authorized for people ages 18 and older, and one by Pfizer that is authorized for people 16 and older. The Food and Drug Administration (FDA) has determined a third vaccine, created by Johnson & Johnson, is safe and effective at preventing severe Covid-19 in people 18 and older, and they will meet to review the vaccine for authorization on Friday.








But why is there an age limit for who can receive a vaccine right now, and when will a vaccine become available for kids and teenagers?








Vaccinating young people will be necessary to approach herd immunity and significantly slow the spread of Covid-19 in the United States, Sarah Zhang reports for the Atlantic. The FDA has specific regulations and protections in place for testing new medications in children, in order to reduce risk. That means that vaccine trials have to be conducted separately for adults and children.








Pfizer has enrolled about 2,300 volunteers between 12 and 15 years old in a vaccine trial, and they hope to have initial data by this summer, Sarah Elizabeth Richards reports for National Geographic. Moderna is still recruiting volunteers and expects to have data in 2022, ProPublica public health journalist Caroline Chen tells Hari Sreenivasan at PBS Newshour.








Why do kids need a Covid-19 vaccine?








On a community level, a kid who catches Covid-19 has the potential to spread that virus to the adults in their life who may not have gotten vaccinated yet. Some people can’t get vaccinated because of their immune systems or because they have a history of allergic reactions to vaccines, for example.








On an individual level, kids face the risk of severe symptoms that could make them miss school, and make their parents miss work. “Even those two-to-three-day illnesses can pile up,” says pediatrician Jeff Gerberof the Children’s Hospital of Philadelphia, to the Atlantic.








In rarer cases, some children have reported long-lasting symptoms after their initial course of Covid-19 in a way that resembles “long Covid” in adults. Other times, an inflammatory condition called MIS-C appears weeks or months after the infection, which can be treated with hospitalization.








About 250 children have died of Covid-19 in the United States out of over 500,000 deaths total. That makes it among the more serious diseases that a child could catch. To put it in perspective, Covid-19 is “causing more deaths than influenza does in a typical season,” and it’s recommended that children get an annual flu vaccine because of that risk, says pediatrician and bioethicist Douglas Diekema of Seattle Children’s Hospital to Science magazine’s Jennifer Couzin-Frankel. Diekema continues, “Those are unnecessary deaths and should be prevented.”








Why were the first vaccines just approved for adults?








Vaccine trials happen in order of “age de-escalation,” beginning with adults, who are the most at-risk of Covid-19 that’s severe enough to require hospitalization. After several phases of testing, culminating in a trial with tens of thousands of volunteers, the FDA reviews the companies’ data for the vaccines’ efficacy, and very importantly, their safety.








Only after proving that the vaccine is safe and effective in adults can the companies begin trials in children.








“Some people have wondered why kids weren’t enrolled in Covid-19 trials earlier, but the purpose of these regulations is to protect kids from unnecessary risk,” says St. Jude Children’s Research Hospital Ethics Committee chairperson Liza-Marie Johnson to National Geographic. “Research is opened to minors when a trial is low risk and offers potential for benefit.”








Some vaccine trials were halted or paused because an adult volunteer had an adverse side effect; regulations reduce the risk of that happening to a child during trials for younger age groups.








Continuing with the age de-escalation strategy, the next trials will test full-dose vaccines for safety and immune response in adolescents over 11 years old. After that, companies can move to children over six years old, and then to infants. Some scientists have advocated for testing half- and quarter-dose vaccines in younger children.








“If you get the same immune response at a quarter of the dose and it decreases side effects, well then we would probably give a smaller dose,” says Robert Frenck, who directs Cincinnati Children’s Hospital’s Gamble Vaccine Research Center and is involved in Pfizer’s adolescent trial, to Science magazine.








Over 20 million people have been fully vaccinated in the United States, with few lasting side effects, according to the FDA.








“They’re really looking at the data very, very closely,” says Mount Sinai Hospital pediatrician Kristin Oliver to the New York Times’ Apoorva Mandavilli. “As a pediatrician and a mom, I have really good confidence that those systems work.”








How are the trials different for adults and children?








The trials in adults waited for a small number of tens of thousands of participants to test positive for Covid-19, and showed that people with the vaccine were 20-times less likely to catch it than those who weren’t vaccinated. Now, the trials in adolescents and children will look for signs of immune system activity that can be detected in the blood, so no one has to get sick in order for the companies to gather data.








Megan Egbert’s two daughters are participating in the adolescent vaccine trial for Moderna, and she tells National Geographic that the trial requires that they keep a diary of symptoms for a week after each shot, attend telemedicine appointments regularly, and get four blood draws and four Covid-19 tests over the course of 13 months. They will also each be compensated $1,600. “I tell them this is like a job,” Egbert tells National Geographic.








It may take extra time to approve the vaccine for younger people in part because the vaccine for adults was actually fast-tracked into emergency use authorization, which requires just two months of safety data. The FDA is looking for six months of safety data for the vaccine in adolescents, per the Atlantic.








It can also be difficult to recruit volunteers for a study in younger people, especially if parents don’t feel like their children are under an immediate threat, reports the Atlantic. Praxis Communications’ senior vice president and managing director Tricia Barrett tells National Geographic that they focus on giving participants an emotional connection to the purpose of clinical trials.








“There’s a big sense of altruism. Parents think, 'I’m not only helping my child, but others as well,'” she says. “For the kids, we help make them feel like part of something cool.”














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