Greek scientists discover new nuclear materilas

Greek scientists discover new nuclear materilas

By NewsRoom™ → Apr 28, 2018

EVANSTON, IL – A research team from Northwestern University and Argonne National Laboratory has developed a remarkable “next-generation” material for nuclear radiation detection that could significantly decrease the cost of detectors compared to those currently in commercial use.

“Specifically, the high-performance material is used in a device that can detect gamma rays, weak signals given off by nuclear materials, and can easily identify individual radioactive isotopes. It has been more than 30 years since a material with this performance was developed, with the new material having the advantage of inexpensive production,” Northwestern Now, the university’s newspaper, reported.

According to "The National Herald", among the potential uses for the new device could include more widespread detectors, such as handheld versions, for nuclear weapons and materials as well as applications in biomedical imaging, astronomy, and spectroscopy.

Mercouri G. Kanatzidis, the corresponding author of the paper which was published in the journal Nature Communications is a Charles E. and Emma H. Morrison Professor of Chemistry in the Weinberg College of Arts and Sciences and also has a joint appointment with Argonne.

He said, “Governments of the world want a quick, low-cost way to detect gamma rays and nuclear radiation to fight terrorist activities, such as smuggling and dirty bombs, and the proliferation of nuclear materials. This has been a very difficult problem for scientists to solve. Now we have an exciting new semiconductor device that is inexpensive to make and works well at room temperature,” Northwestern Now reported.

“In 2013, Argonne published a scientific study noting the promise of cesium lead bromide in the form of perovskite crystals for high-energy radiation detection. Since then, researchers led by Kanatzidis, Duck Young Chung of Argonne and Constantinos Stoumpos of Northwestern have worked to purify and improve the material,” Northwestern Now reported.

The step forward was when Yihui He, a postdoctoral fellow in Kanatzidis’ group and the paper’s first author, used the improved material and reconfigured the semiconductor device. “Instead of using the same electrode on either side of the crystal, he used two different electrodes,” Northwestern Now reported, adding that “with this asymmetrical design, the device only conducts electricity when gamma rays are present.”

In comparing the new new cesium lead bromide detector to a conventional cadmium zinc telluride (CZT) detector, the research team found the results detecting gamma rays were the same.

“We achieved the same performance in two years of research and development as others did in 20 years with cadmium zinc telluride, the expensive material that is currently used,” Kanatzidis said, Northestern Now reported, adding that “it is important to know what the gamma-ray emitting material is, Kanatzidis stressed, because some materials are legal and some are illegal. Each radioactive isotope possesses its own ‘fingerprint’: a different decay behavior and a unique characteristic gamma-ray emission spectrum. The new cesium lead bromide detector can detect these fingerprints.”

The research team also tested radioactive isotopes which were successfully identified by the new detector and “also produced larger crystal samples to demonstrate the material can be scaled up,” Northwestern Now reported.

The Department of Energy, National Nuclear Security Administration, Office of Defense Nuclear Nonproliferation Research and Development (contract No. DE-AC02-06CH11357, Argonne National Laboratory) and the Department of Homeland Security ARI program (grant 2014-DN-077-ARI086-01) supported the research.

The paper, entitled “High spectral resolution of gamma-rays at room temperature by perovskite CsPbBr single crystals,” is available online at https://www.nature.com/articles/s41467-018-04073-3.

MIT Prof. Costis Daskalakis Talks about Artificial Intelligence

MIT Prof. Costis Daskalakis Talks about Artificial Intelligence

By NewsRoom™ → Apr 26, 2018

Humanity’s journey toward developing true Artificial Intelligence “is the human brain’s wager with Darwinian evolution,” according to Prof. Constantinos Daskalakis, the X-Window Associate Professor of Electrical Engineering and Computer Science at the Massachusetts Institute of Technology (MIT). The 36-year-old professor who is noted for his work advancing the understanding of Nash Equilibria, was interviewed by the Athens-Macedonian News Agency (ANA) during a recent trip to Greece, where he gave lectures at Greek universities.

“One of the highest functions that the human brain can do is to copy itself. When humans reach the point of reproducing their own abilities in an artificial way, then everything is open and everything is possible. This can be amazing, it can lead us to a Wonderland where the existence of machines will work in humanity’s favour or it can lead us to unpleasant situations,” Daskalakis said, when asked if he shared the fears expressed by noted scientists and leaders in the field of technology – such as Bill Gates, Stephen Hawking and Elon Musk – about the possible negative repercussions for humans of rapidly developing AI and especially Artificial General Intelligence.

“Elon Musk has said that AI could be the cause of World War 3. I would remind you, however, of what Einstein said: “I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones,” Daskalakis noted.

Even though AI causes serious social upheavals that are a direct threat to democracy in the dystopian view of the future, Daskalakis noted, the positive slant promised great gifts and benefits: “I believe that there is a very capable and democratic family of ‘hackers’ – and I include in this family anyone capable of understanding the technology and contributing to it. It is up to them and up to all of us to protect the access of all people to the benefits of the progress that will be made, so that ‘two-speed’ countries, companies or citizens do not exist. This is not a thing that we can play with,” he said.

Asked whether humans, whose primacy on the planet is in question for the first time, will suffer an existential shock, he replied: “I hope that the opposite will happen. That we will be able to say ‘We are no longer hostages of politicians and governments; we can change the world.’ This is the good scenario, of course, and that is what I want to see happen.”

Asked if systems such as education or the law will have time to adjust, Daskalakis noted that the current systems for education, legislation and justice “are no longer adequate, given the rate with which technology is progressing.”

“Look at it this way: before we had time to pass legislation on fake news, there was a tornado of fake news that been and gone. We will draw up the legislation for fake news and something else will turn up. The way that democracies and education works is not fast enough to keep pace with developments, therefore we need to change our models. That is why I think that the base, the people, have enormous power. If the base itself does not protect me from fake news, for example, I cannot expect that legislation will be passed that will defend me. All this is turning into something like a guerrilla war,” he said.

The Greek professor, a winner of the Kalai Prize awarded by the Game Theory Society and the Giuseppe Sciacca research prize, also spoke to ANA about the use of technological implants in humans, the moral and philosophical questions that arise from the development of AI and the way things are likely to unfold over the next five to 50 years.

He was interviewed by the ANA a few hours before his lecture at University of Thessaloniki, as part of an event organised by the university’s Mathematics and IT faculties.

DNA analysis sheds light on the origin of Minoans and Mycenaeans

DNA analysis sheds light on the origin of Minoans and Mycenaeans

By NewsRoom™ → Apr 20, 2018

According to "Keep Talking Greece", during the Bronze Age, two important civilizations emerged in Greece: the Minoans and, later, the Mycenaeans. These ancient peoples were among the earliest of the so-called “high cultures” of Europe: they communicated with sophisticated writing systems, painted elaborate frescoes, and—in the case of the Mycenaeans—built fortifications so large that later Greeks believed the structures had been created by giants.

As Megan Gannon reports for Live Science, researchers recently conducted an extensive genomic analysis of Minoan and Mycenaean DNA. Their findings suggest that the two groups shared common ancestry, and that they are genetically linked to the Greeks of today.

 The study, published in the journal Nature, sought to unravel one of the enduring mysteries of classical scholarship. Although the Minoans and Mycenaeans left behind plenty of material evidence, archaeologists have long puzzled over the groups’ origins.
 Sir Arthur Evans, the archaeologist who found evidence of a distinct Minoan culture, believed that the group may have hailed from Egypt; others have suggested that the Mediterranean, Turkey, or Europe as more likely points of origin. The Myceneans have similarly confounded experts, as Louise Schofield writes in The Mycenaeans. Early researchers thought the culture was established by foreign invaders who spoke an early version of Greek. “However, more recent thinking tends to the view that it is too simplistic to think in terms of a single wave of Greek-speakers sweeping into the area,” according to Schofield.
Additionally, traditional scholarship has posited that the Minoans and Mycenaeans were two distinct peoples, according to Phys.org. But the new study suggests that this might not be the case.

Researchers analyzed DNA samples from 19 Bronze Age individuals. Ann Gibbons of Science reports that the remains belonged to 10 Minoans from Crete, four Mycenaeans, and five people from other early Bronze Age cultures of Greece and Turkey. The team compared 1.2 million letters of genetic code from these individuals to the genomes of 334 people from other ancient cultures, along with those of 30 modern Greeks.

In a significant revelation, researchers found that Minoans and Mycenaeans were closely related. At least three-quarters of DNA from both groups came from “the first Neolithic farmers of Western Anatolia and the Aegean,” the authors of the study write. Both cultures also inherited DNA from the peoples of the eastern Caucasus, located near modern-day Iran.

“This finding suggests that some migration occurred in the Aegean and southwestern Anatolia from further east after the time of the earliest farmers,” says Iosif Lazaridis, a Harvard University geneticist and co-author of the study, according to Phys.org.

Though the genomes of the Minoans and Mycenaeans were similar, they were not identical. Interestingly, the Mycenaeans shared four to 16 percent of their DNA with early hunter-gatherers of eastern Europe and Siberia. The authors of the study speculate that this finding points to another early migration to Greece—one that did not reach the Minoan homestead of Crete.

Researchers also observed genetic links between the Mycenaeans and modern inhabitants of Greece, “with some dilution of the early Neolithic ancestry,” the authors of the study write. The team posits that their findings “support the idea of continuity but not isolation in the history of populations of the Aegean.”

As Gibbons points out, the study’s findings are particularly nifty because ancient Greeks believed that they hailed from the early inhabitants of the Aegean. Homer’s account of the Trojan War, for instance, tells of an epic battle waged by Agamemnon—king of Mycenae and leader of the Greek troops. The heroes of ancient mythology were fictional, of course, but the genetic connections between successive Greek cultures may have been very real indeed.

To tell you the truth when I was at elementary school 5.-6. grade I was always thinking Minoans and Mycenaeans were optically if not the same, at least relatives.