Monday, May 9, 2022

Seawater to Drinking Water


MIT researchers have developed a suitcase-sized portable desalination unit that can remove particles and salts to render drinking water that exceeds World Health Organization quality standards. The device runs with the push of one button and requires less power to operate than a cell phone charger. It also can be charged by solar power.

Unlike other portable desalination units that require water to pass through filters, this device utilizes electrical power to remove particles from drinking water. Eliminating the need for replacement filters greatly reduces the long-term maintenance requirements.

The unit relies on ion concentration polarization (ICP). Rather than filtering water, the ICP process applies an electrical field to membranes placed above and below a channel of water. The membranes repel positively or negatively charged particles — including salt molecules, bacteria, and viruses — as they flow past. The charged particles are funneled into a second stream of water that is eventually discharged.

The researchers also created a smartphone app that can control the unit wirelessly and report real-time data on power consumption and water salinity.

This unit could be deployed in remote and severely resource-limited areas, such as communities on small islands or aboard seafaring cargo ships. It also could be used to aid refugees or by soldiers carrying out long-term military operations.

Read more here and here.

Sunday, April 24, 2022

The Intriguing Story of the Dingo


The Australian dingoes descend from domesticated dogs coming from East Asia, probably with the Austronesian expansion into Island Southeast Asia around 6000 years ago. They were introduced from a small population of dogs and have since roamed wild in most of Australia.

That is the belief of some researchers. However, others question whether dingoes’ ancestors were ever domesticated. The dingo is a genetic intermediate between domestic dogs and wild wolves. This is probably because dingoes spent thousands of years isolated from other dog species. Modern domestic dogs didn’t arrive in Australia until 1788, when they were introduced by Europeans.

Bill Ballard at La Trobe University in Melbourne, Australia, believes that the dingo may have been introduced to Australia as a tamed wild animal, one accustomed to living alongside people but not domesticated through selective breeding.

In 2017, the dingo won the “World’s Most Interesting Genome” competition held by US biotech company Pacific Biosciences.

Read more here and here.

Saturday, April 2, 2022

The Mysterious Mustatils


Photo credit: Huw Groucutt

In the north of the Arabian Peninsula, bordering the Nefud Desert, archaeologists recently catalogued vast stone monuments dating back 7,000 years. These are called mustatils, meaning “rectangles” in Arabic.

Over 1000 of these prehistoric sandstone walls are found in northwest Saudi Arabia. They are clustered in groups of two to 19 and spread across 200,000 square kilometers (77220. sq miles). 

The largest mustatil is over 1,500 feet long and consists of 12,000 tons of stone. Recent fieldwork in AlUla and Khaybar Counties, Saudi Arabia, demonstrates that these structures are architecturally complex, featuring chambers, entranceways and orthostates.

A team of archaeologists led by Huw Groucutt of the Max Planck Institute for Chemical Ecology in Germany has been studying satellite images of the southern edge of the Nefud Desert. The team identified and studied 104 new mustatils up close.

First discovered in the 1970s, the purpose of these rectangular structures remains mysterious. One theory is that they are sacred enclosures for ceremonial gatherings and feasts. "Our interpretation of mustatils is that they are ritual sites, where groups of people met to perform some kind of currently unknown social activities," Groucutt said. "Perhaps they were sites of animal sacrifices, or feasts."

The structures were built during the African Humid Period (12,600 B.C. to 4,000 B.C.). During this time, the Sahara and the Arabian Peninsula had more plentiful rainfall and the regions were green with lush vegetation.

Read more here.

Thursday, March 31, 2022

Reference Human Genome Almost Complete


Work remains to finalize the reference genome (the Y chromosome still needs to be finished) but researchers are close to finally sequencing every last nucleotide of human DNA.

Ever since the launch of the Human Genome Project more than 30 years ago, genetic sequencing technologies and data-processing pipelines have been getting faster, cheaper and more precise, allowing researchers to sample, sequence and compare more genomes with every passing year.

But huge chunks of DNA – amounting to around 8 percent of the human genome – were still missing from the most recent reference sequence that scientists use as a template to assemble newly-sequenced DNA samples.

Now, scientists have pieced together those parts of the human genome which have long been 'unsequenceable' to assemble the most complete reference genome to date, sharing their findings in a collection of six papers, published in the journal Science.

Read more here and here.

Wednesday, March 23, 2022

Our African Ancestors


All living humans share a common point of origin in eastern Africa. Every person living today is descended from hunter-gatherers in Africa thousands of years ago. On our genetic profiles this appears as mtDNA Macro-haplogroup L, also known as Mitochondrial Eve/Eva. This should not be confused with the biblical Eve who lived no earlier than 7200 years ago.

Overview of the main divisions of haplogroup L.

About 300,000 years ago, people in Africa made new kinds of stone tools and began transporting raw materials up to 250 miles (400 kilometers), likely through trade networks. By 140,000-120,000 years ago, people wore animal skins and pierced marine shell beads.

A new genetic study indicates "The presence of eastern African ancestry as far south as Zambia, and southern African ancestry as far north as Kenya, indicates that people were moving long distances and having children with people located far away from where they were born. The only way this population structure could have emerged is if people were moving long distances over many millennia."

After a period of extensive population movements during which peoples from different regions intermarried, a change took place. Marriage partners were chosen from nearby.

The researchers used their study of Ancient DNA (aDNA) to create "the largest genetic dataset so far for studying the population history of ancient African foragers – people who hunted, gathered or fished. We used it to explore population structures that existed prior to the sweeping changes of the past few thousand years."

The DNA sampling was not uniform and not all of the individuals lived contemporaneously. However, "on average individuals from the same or nearby sites proved to be more closely related than predicted solely on the basis of the broad regional genetic structure, but this relatedness extends only over short distances, particularly within Malawi and Zambia."

This study focuses on population movements within Africa. It does not refer to the movements out of Africa. Stone tools dating to 1.5 million years have been found in Saudi Arabia near the Red Sea. 

The oldest stone tool to be found in Turkey reveals that humans passed through the gateway from Asia to Europe approximately 1.2 million years ago. The worked quartzite flake was found in ancient deposits of the river Gediz in western Turkey.

A trove of hand axes dating to 500,000 years ago was found in central Israel at Jaljulya

Thomas Strasser and Eleni Panagopoulou found stone tools on the southwestern shore of Crete, near Plakias. These date to between 200,000 and 100,000 years. 

A young male was buried 100,000 years ago in Qafzeh Cave in Lower Galilee.

Evidence of human habitation 100,000 years ago in the area of Bethlehem is attested along the north side of Wadi Khareitun where there are three caves: Iraq al-Ahmar, Umm Qal’a, and Umm Qatafa. These caves were homes in a wooded landscape overlooking a river. At Umm Qatafa archaeologists have found the earliest evidence of the domestic use of fire in Palestine.

Saturday, March 19, 2022

1921 Fossil Fuel Prediction and the Alligator Pear


A woman with a Chrysler vehicle, circa 1920s.
(Gamma-Keystone via Getty Images)

This 1921 Science News report predicts modifications to combustion engines that will reduce gasoline consumption. The article was written by E. H. Leslie, Associate Professor of Chemical Engineering at the University of Michigan. He mentions the production of "synthetic gasoline" and the future increased dependence of the United States on imported petroleum products.

H. the production of "synthetic gasoline" and the future increased dependence of the United States on imported petroleum products.

The paper includes a report on the Alligator Pear, otherwise known as the avocado. At the time of the report (July 18, 2921) over 1200 acres of avocados grew in Florida and California. The cost of this fruit was high in the 1920s due to scarcity. The growers have managed to sustain the high prices throughout the subsequent decades.

STEM students will find the Science News Archives helpful for research on historical developments in science.

Wednesday, March 9, 2022

Remembering John Polkinghorne One Year Later


“Science is privileged to investigate a universe that is both rationally transparent and rationally beautiful. Scientists frequently speak of the experience of wonder as the reward for all the weary labour involved in their research.” - John Polkinghorne

John Polkinghorne died on 9 March 2021. He was an English particle physicist, theologian, Anglican priest, and Professor of Mathematical Physics at Cambridge University. He served as the president of Queens' College, Cambridge from 1988 until 1996.

His achievements were recognized in 1974 by his election as a Fellow of the Royal Society. His work concentrated on quantum physics and the theory of elementary particles. He published a large volume of papers and his books ranged from research texts to popular science such as The Particle Play (1979) and The Quantum World (1984).

In 1977, he decided that he had “done [his] bit for physics”, and he resigned from his university position to begin a second career in the Church. He was ordained a priest in 1982. He served as canon theologian of Liverpool Cathedral from 1994 to 2005.

After a number of years as a parish priest he returned to the academic world and made a significant contribution to the field of science and religion, something he continued to do until his death at age 90.

In his 2007 book Quantum Physics and Theology: An Unexpected Kinship (London: SPCK), Polkinghorne articulated five points of comparison between the ways in which science and theology pursue truth: moments of enforced radical revision, a period of unresolved confusion, new synthesis and understanding, continued wrestling with unresolved problems, deeper implications.

Polkinghorne believed that because "we are creatures made in the divine image, then it is entirely understandable that there is an order in the universe that is deeply accessible to our minds." It seems natural then that Dr. Polkinghorne would turn to theology as a way to shine light on reality and the material world. Polkinghorne suggests that the experience of meaning in the practice of science hints at God. Science and theology explore a common reality and therefore, share a common starting point for meaningful dialogue.

In the 2008, Polkinghorne wrote, "There are aspects of our scientific understanding of the universe that become more deeply intelligible to us if they are viewed in a Trinitarian perspective." (Science and the Trinity, p. 61)

He considered himself a "creationist", but he rejected the literalism of American Fundamentalism. In an article published in 2008 in The Times, Polkinghorne wrote:

An irritating feature of modern life is the way in which useful words get hijacked and used for different, and often unacceptable, purposes. An example is “creationist”. As a Christian believer I am, of course, a creationist in the proper sense of the term, for I believe that the mind and the purpose of a divine Creator lie behind the fruitful history and remarkable order of the universe which science explores. But I am certainly not a creationist in that curious North American sense, which implies interpreting Genesis 1 in a flat-footed literal way and supposing that evolution is wrong.

The irony of this notion of creationism is that it not only involves many scientific errors, but is also the result of a bad theological mistake. When we read any kind of deep literature, if we are to give it the respect that it deserves we must make sure we understand the genre of what is written. Mistaking poetry for prose can lead to false conclusions. When Robert Burns tell us his love “is like a red, red rose”, we know that we are not meant to think that his girlfriend has green leaves and prickles. Reading Genesis 1 as if it were a divinely dictated scientific text, intended to save us the trouble of actually doing science, is to make a similar kind of error. We miss the point of the chapter if we do not see that it is actually a piece of deep theological writing whose purpose, through the eight-times reiterated phrase “And God said, ‘Let there be . . .”, is to assert that everything that exists does so because of the will of the Creator. Thus literal creationists actually abuse scripture by the mistaken interpretation that they impose upon it.

Related reading: Remembering John Polkinghorne by Tom C. B. McLeish (University of York, UK); Obituary: The Revd Professor John Polkinghorne

Monday, February 28, 2022

Patagonian Mountains Rise as Ice Caps Shrink

Mount Fitz Roy and surrounding peaks on the border between Argentina and Chile.
(Photo: Ben Tiger)

The icefields that stretch for hundreds of miles atop the Andes in Chile and Argentina are melting at some of the fastest rates on the planet. The ground that was beneath this ice is rising as these glaciers disappear.

Geologists have discovered a link between recent ice mass loss, rapid rock uplift and a gap between tectonic plates that underlie Patagonia.

Scientists at Washington University in St. Louis, led by seismologist Douglas Wiens, the Robert S. Brookings Distinguished Professor in Arts & Sciences, recently completed one of the first seismic studies of the Patagonian Andes. In a new publication in the journal Geophysical Research Letters, they describe and map out local subsurface dynamics.

Shrinking icefields have reduced weight that previously caused the continent to flex downward. The scientists found very low seismic velocity within and around the gap, as well as a thinning of the rigid lithosphere overlying the gap. The ongoing movement of land is known as glacial isostatic adjustment.

These particular mantle conditions are driving many of the recent changes that have been observed in Patagonia, including the rapid uplift in certain areas once covered by ice. 

Researcher Wiens reports, "Low viscosities mean that the mantle responds to deglaciation on the time scale of tens of years, rather than thousands of years, as we observe in Canada for example." Wiens explains, "This explains why GPS has measured large uplift due to the loss of ice mass.

"Another significant thing is that the viscosity is higher beneath the southern part of the Southern Patagonia Icefield compared to the Northern Patagonia Icefield, which helps to explain why uplift rates vary from north to south," Wiens said.

Wiens specializes in seismology and geophysics and has done extensive research on large deep earthquakes in the Pacific Ocean, the effect of ice melt, and the seismology of Antarctica. 

Read more herehere, and here.

Saturday, February 19, 2022

A Turbulent Sun

NOAA Solar Cycle Chart, October 29, 2020

News sources are picking up on the fact that the solar maximum is approaching in July 2025, with an increase in the number of sunspots. Sunspots often appear in pairs with different magnetic polarities. They become more prevalent every 11 years (solar cycle) and they migrate through latitudes, moving closer to the equator as the solar cycle progresses. 

SpaceWeatherLive tracks solar activity and reports that the Sun has erupted from February 1st through the 17th with some days featuring multiple flares. That includes three flares of the second-most powerful category: an M1.4 on February 12; an M1 on February 14; and an M1.3 on February 15. 

There were also five M-class flares in January. The mild geomagnetic storm that knocked 40 newly launched Starlink satellites from low-Earth orbit followed an M-class flare that took place on January 29.

Solar flares happen because of the constantly moving magnetic fields in the Sun's atmosphere. The frequency of solar flares coincides with the Sun's 11-year cycle. When the solar cycle is at a minimum, fewer solar flares are detected. Flares increase in number as the Sun approaches the maximum part of its cycle.

A solar cycle: a montage of ten years' worth of Yohkoh SXT images, showing the variation in solar activity during a sunspot cycle, after 30 August 1991 to 6 September 2001. Credit: Yohkoh mission of ISAS (Japan) and NASA.

The Sun's magnetic field has a north pole and a south pole. About every 11 years, the Sun's magnetic field does a flip. The north pole becomes the south pole, and vice versa.

This flip is one feature of the solar cycle. As the cycle progresses, the Sun's stormy behavior builds to a maximum, and that is when the magnetic field reverses. Then the Sun settles back down to a minimum, only to start another cycle.

Solar storms are not unusual. An ancient solar storm happened around7200 BC when most humans lived at Earth's middle latitudes, not near the poles. Another big storm came between 775-774 BC. By then humans were more widely dispersed and yet they survived that event. 

However, in those times people did not rely on the technologies that we have today. On March 13,1989 the entire province of Quebec, Canada suffered an electrical power blackout caused by a solar storm. Some are concerned that a future large solar storm could return Earth to the dark ages.

Tuesday, February 15, 2022

Potential AI Breakthrough on Neurodegenerative Disease


Jeremy Linsley: Scientific Program Leader at Gladstone Institutes, University of California, San Francisco. 

new artificial intelligence technology his research team developed can identify dead cells with both superhuman accuracy and speed. This advance could potentially turbocharge all kinds of biomedical research, especially on neurodegenerative disease.

Jeremy explains:

Understanding when and why a cell dies is fundamental to the study of human development, disease and aging. For neurodegenerative diseases such as Lou Gehrig’s disease, Alzheimer’s and Parkinson’s, identifying dead and dying neurons is critical to developing and testing new treatments. But identifying dead cells can be tricky and has been a constant problem throughout my career as a neuroscientist.

Until now, scientists have had to manually mark which cells look alive and which look dead under the microscope. Dead cells have a characteristic balled-up appearance that is relatively easy to recognize once you know what to look for. My research team and I have employed a veritable army of undergraduate interns paid by the hour to scan through thousands of images and keep a tally of when each neuron in a sample appears to have died. Unfortunately, doing this by hand is a slow, expensive and sometimes error-prone process.

Making matters even more difficult, scientists recently began using automated microscopes to continually capture images of cells as they change over time. While automated microscopes make it easier to take photos, they also create a massive amount of images to manually sort through. It became clear to us that manual curation was neither accurate nor efficient. Furthermore, most imaging techniques can detect only the late stages of cell death, sometimes days after a cell has already begun to decompose. This makes it difficult to distinguish between what actually contributed to the cell’s death from factors just involved in its decay.

My colleagues and I have been trying for some time to automate the curation process. Our initial attempts could not handle the wide range of cell and microscope types we use in our research, nor rival the accuracy of our interns. But a new artificial intelligence technology my research team developed can identify dead cells with both superhuman accuracy and speed. This advance could potentially turbocharge all kinds of biomedical research, especially on neurodegenerative disease.

Source: The Conversation: New AI technique identifies dead cells under the microscope 100 times faster than people can

Jeremy Linsley is a neuroscientist with a demonstrated and diverse skillset within academic biomedical research. Skilled in calcium imaging, cell culture, high-throughput microscopy, 4D microscopy, behavioral analysis, molecular biology, disease genetics, zebrafish, drosophila, hIPSC, primary tissue, organotypic slice culture, deep learning and artificial intelligence. Doctor of Philosophy (PhD) in Cellular and Molecular Biology with John Kuwada at the University of Michigan, and postdoctoral fellowship at Gladstone Institutes with Steve Finkbeiner.

Wednesday, February 9, 2022

University of Delaware Engineers Attack CO2 Pollution


Three fuel cell experts discuss their project. From left to right, Yushan Yan, Brian P. Setzler, and Shimshon Gottesfeld. (Photo: Evan Krape)

The University of Delaware engineers captured 99% of carbon dioxide in the air when using their novel hydrogen-powered electrochemical system. The UD engineers have developed a fuel cell technology that uses cheaper catalysts and structural components, but these hydroxide exchange membrane fuel cells (HEMFCs) have a limitation. They cannot use direct supply of ambient air, because the carbon dioxide in the air reduces their performance.

The alkaline environment of hydroxide exchange membrane fuel cells potentially allows use of cost-effective catalysts and bipolar plates in devices. However, HEMFC performance is adversely affected by CO2 present in the ambient air feed. Here, we demonstrate an electrochemically driven CO2 separator (EDCS) to remove CO2 from the air feed using a shorted membrane that conducts both anions and electrons. This EDCS is powered by hydrogen like a fuel cell but needs no electrical wires, bipolar plates or current collectors, and thus can be modularized like a typical separation membrane.

The University of Delaware team has been attempting to improve fuel cell technology for over fifteen years. They realized that the sensitivity of the fuel cell to carbon dioxide, while detrimental to its efficiency in converting the chemical energy in fuel to electricity, meant it could be used as an effective tool for capturing carbon dioxide from the atmosphere.

An early prototype they developed using this approach, about the size of a 12-ounce (355 mL) soda can, could filter 10 liters of air per minute while scrubbing out >98% of the carbon dioxide present.

Brian Setzler, assistant research professor in chemical and biomolecular engineering and paper co-author explains, "Once we dug into the mechanism, we realized the fuel cells were capturing just about every bit of carbon dioxide that came into them, and they were really good at separating it to the other side," said

"It turns out our approach is very effective. We can capture 99% of the carbon dioxide out of the air in one pass if we have the right design and right configuration," said Professor Yushan Yan, Henry Belin du Pont Chair of Chemical and Biomolecular Engineering at the University of Delaware.

“This carbon dioxide problem has been with us for long enough, and we decided to turn the problem on its head and make it into a solution,” said Yan.

Read more here and here.  

Saturday, February 5, 2022

MIT Engineers Rock the "Impossible"


Using a novel polymerization process, MIT chemical engineers have created a new lightweight material stronger than steel. The new substance is the result of polymerizing a material in two dimensions.

The new material is a two-dimensional polymer that self-assembles into sheets, unlike all other polymers, which form one-dimensional, spaghetti-like chains. Until now, scientists had believed it was impossible to induce polymers to form 2D sheets.

The researchers found that the new material’s elastic modulus — a measure of how much force it takes to deform a material — is between four and six times greater than that of bulletproof glass. They also found that its yield strength, or how much force it takes to break the material, is twice that of steel, even though the material has only about one-sixth the density of steel.

Such a material could be used as a lightweight, durable coating for car parts or cell phones, or as a building material for bridges or other structures, says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and the senior author of the new study.

“We don’t usually think of plastics as being something that you could use to support a building, but with this material, you can enable new things,” he says. “It has very unusual properties and we’re very excited about that.”

The researchers have filed for two patents on the process they used to generate the material, which they describe in a paper appearing today in Nature. MIT postdoc Yuwen Zeng is the lead author of the study.

Read more here and here.

Sunday, January 16, 2022

Acceleration of Wind at Jupiter's Red Spot


Credits: NASA, ESA, Michael H. Wong (UC Berkeley)

Students have seen images of Jupiter's Great Red Spot. That dot shows a huge storm and the winds are slowly but steadily accelerating! The acceleration of the winds in the outermost "lane" of Jupiter's Red Spot has been detected by NASA's Hubble Space Telescope, which has monitored the planet for more than a decade.

Researchers analyzing Hubble's "storm reports" from 2009 to 2020 found that the average wind speed within the boundaries of the storm's high-speed ring has increased by up to 8 percent and exceed 400 miles per hour. In contrast, the winds near the storm's innermost region, set off by a smaller green ring, are moving significantly more slowly. Both move counterclockwise.

Astronomers have pursued ongoing studies of the "king" of solar system storms since the 1870s. The Great Red Spot is an upwelling of material from Jupiter's interior. If seen from the side, the storm would have a tiered wedding cake structure with high clouds at the center cascading down to its outer layers. Astronomers have noted that it is shrinking in size and becoming more circular than oval in observations spanning more than a century. The current diameter is 10,000 miles across, meaning that Earth could still fit inside it.

Read more here.