Tag Archive | "college of arts and sciences"

Physicist Helps Unlock  Secrets of the Universe

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Physicist Helps Unlock Secrets of the Universe


A team member on Japan’s Hitomi mission, Massimiliano Galeazzi helped develop the systematic goals and strategies for a satellite designed to study black holes and the evolution of the universe.

By Deserae E. del Campo
Special to UM News

A radiation measurement of the Perseus galaxy cluster, as captured by the Hitomi satellite.

A radiation measurement of the Perseus galaxy cluster, as captured by the Hitomi satellite.

CORAL GABLES, Fla. (July 14, 2016) – Scientists built it to peer into the far reaches of outer space, with a mission to explore the nature of black holes, mysterious dark matter, and even the origins of the universe. But when Japan’s Hitomi satellite spiraled out of control only a month after achieving orbit earlier this year, astronomers thought all was lost.

Then came the news that made scientists like the University of Miami’s Massimiliano Galeazzi breathe a sigh of relief. In its short life, the doomed satellite had collected valuable X-ray data from a distant galaxy cluster—the kind of information astronomers had been waiting for years to obtain.

“Clusters are the building blocks of the universe,” said Galeazzi, associate chair and professor of physics in the University of Miami’s College of Arts and Sciences, who collaborated with the Japan Aerospace Exploration Agency (JAXA) and NASA to develop the systematic goals and strategies for the Hitomi mission. “Hitomi could measure much better than anything before it the energy or wavelength of the X-ray radiation coming from an astronomical object.”

With its next-generation X-ray instrument developed and built at NASA’s Goddard Space Flight Center by scientists from the U.S., Japan, and the Netherlands, Hitomi, which translates to “pupil of the eye” in Japanese, captured X-ray gasses emitting from the Perseus cluster, a collection of galaxies joined by gravity and located 240 million light years from Earth. The cluster radiates hot gasses, averaging 90 million degrees, which before were unmeasurable by astrophysicists.

Scientists studied the data captured by Hitomi and found that the hot gasses between galaxies within the cluster are moving at a slower speed and in a less turbulent manner than expected. Studying the movement and turbulence of gas is a vital tool for understanding the growth and parameters of the universe and how galaxies form and evolve.

“The level of details obtained by the investigation is breathtaking, showing the incredible power of the X-ray instrument aboard the Hitomi satellite,” said Galeazzi. “Although the satellite was lost prematurely, the instrument has revolutionized the field of X-ray astrophysics and paved the way for the next generation of X-ray telescopes.”

The X-ray instrument abroad the Hitomi satellite measured an array of emissions from the cluster such as iron, nickel, chromium, and manganese—elements apparent in the stars located in the cluster’s galaxies. The satellite’s data also showed that the gasses’ turbulent motion is practically nonexistent, which leaves scientists to wonder: what is keeping the cluster’s gasses so hot?

Andrew Fabian, an astronomer and astrophysicist at the University of Cambridge’s Institute of Astronomy, says, “This result from Hitomi is telling us that in terms of how cluster cores work, we have to think very carefully about what is going on.”

The X-ray data observed by Hitomi is an indication of the advances satellites can detect in the far reaches of space. The European Space Agency plans to send out a next-generation satellite in the 2020s named ATHENA, which will feature 100 times more pixels than Hitomi and be able to explore galaxy clusters and the relationship they play with massive black holes.

The findings from Hitomi’s data collection of the Perseus cluster were published in the journal Nature on July 7 and titled “The quiescent intracluster medium in the core of the Perseus cluster.”

 

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RoboCanes Among Top 10 at RoboCup Championship

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RoboCanes Among Top 10 at RoboCup Championship


robocanes3

Special to UM News

CORAL GABLES, Fla. (July 8, 2015)—The RoboCanes, a team of autonomous, soccer-playing robots developed by students and faculty at the University of Miami College of Arts and Sciences, reached a milestone at the 2016 RoboCup Championship in Germany, the world’s largest artificial intelligence (AI) and robotics event.

The RoboCanes team defeated numerous humanoid soccer squads from around the world before advancing to the intermediate play for the quarterfinal round, which is where the RoboCanes met their match and lost 0-8 from team TU Dortmund, the new outdoor World Champion.

Associate Professor of Computer Science Dr. Ubbo Visser, who leads the RoboCanes project alongside a group of computer science students, said, “We reached a momentous stage at RoboCup. Not only did we come close to making the quarterfinals this year, but we were the only team with robots that could walk stable on various surfaces, from granite to grass and indoor carpet.”

Before the RoboCanes were eliminated from the championship, they overpowered teams from Estonia, Austria, Switzerland, Germany, and China. The robot teams usually include up to 15 students, yet UM’s RoboCanes is made up of only four students from the Department of Computer Science operating up to five robots at one time.

“RoboCup serves as a vehicle to promote robotics and AI research by offering a publicly appealing and formidable challenge,” said Visser. “Building a robot that plays soccer will not generate significant social and economic impact, but the accomplishment is considered a major achievement for the field.”

RoboCup promotes robotics and AI research by offering an integrated research platform that covers areas including reactive behavior, strategy, real-time planning, vision, motor control, context recognition, and more. Next year marks the 20th anniversary of the RoboCup World Championship, taking place in Nagoya, Japan.

Watch a video of the RoboCanes at play.

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VONA/Voices Provides a Safe Space for Writers of Color

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VONA/Voices Provides a Safe Space for Writers of Color


Annual conference at UM nurtures voices that open minds and deepen human understanding

By Meredith Camel
UM News

UM's M. Evelina Galang, front left, who helped move the two-week conference to UM last year, attends a reading with other VONA/Voices at Books & Books in Coral Gables.

UM’s M. Evelina Galang, front left, who helped move the two-week conference to UM last year, meets up with VONA/Voices students for a faculty reading at Books & Books in Coral Gables.

MIAMI, Fla.—Through all the joy, fanfare, and soul-stirring power of a VONA (Voices of Our Nation Arts Foundation) literary reading, there remains a palpable pain body—one festered through experiences of exclusion as writers of color.

“In the seven layers of your skin are seven centuries of damage that brought you here,” reads author Minal Hajratwala, describing her “wound theory” to a packed theater in Miami’s Little Haiti in June during a VONA/Voices faculty reading. “What’s exhausting is to always cover up the wound.”

Faculty readings were among several free events open to the public during the two weeks that UM hosted VONA/Voices, the only multi-genre conference in the country for writers of color. M. Evelina Galang, director of the UM Creative Writing program and a long-time VONA/Voices faculty and board member, helped move the annual conference to UM from California last year.

“This year, we had a record number of applicants, so Miami, Miami, Miami!” says Diem Jones, who cofounded VONA/Voices in 1999 with fellow authors Elmaz Abinader, Junot Diaz, and Victor Diaz.

Of this year’s 520 applicants from around the world, 150 were selected for workshops in fiction, poetry, memoir, LGBTQ narrative, young adult, and more. All VONA/Voices faculty are “high profile writers committed to social justice, excellent teachers, and who mirror the population we’re trying to reach,” Abinader explains. Among this year’s 14 faculty members was poet John Murillo, a VONA/Voices student in 2003 and visiting assistant professor in the UM Creative Writing program from 2011 to 2012.

In addition to strong writing, VONA/Voices seeks students who think deeply about what it means to be a writer of color as well as those with limited options for craft development. The greatest impact of the conference, Abinader says, is having “a place to feel safe, where no one is judging them based on the stories they access.”

“It’s supportive and nurturing, it builds trust, and it digs deep into their soul,” says Jones, noting that each workshop typically goes through a full box of tissues in a week. “We tell them, ‘Don’t come if your wall is up.’ ”

 

 

 

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Research Finds Women Hold Extremist Groups Together

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Research Finds Women Hold Extremist Groups Together


Special to UM News

A study reveals that although women remain under the radar in terrorist organizations, they hold the networks together

women_extremeCORAL GABLES, Fla. (July 5, 2016) – A team of researchers at the University of Miami who examined the role of women in extreme networks or organizations, such as terrorist groups, dispelled the common assumption that women are lured into these dangerous environments solely to offer support while men are recruited and tend to be the key players. Instead, the researchers found, women are better connected within the network, essentially becoming the glue holding the system together, fueling its vitality and survival.

“The research examines the assumption that, as any kind of real-world situation becomes more dangerous and aggressive, men will dominate—and hence in any network operating under extreme conditions, it is the men that will hold things together,” said Neil Johnson, a physicist in the College of Arts and Sciences. “We had a feeling that the issue of women’s roles—and more generally the role of any numerical minority in human groups or populations that are under stress—is one of prime interest that has not been looked at in sufficient depth.”

For the study, titled “Women’s Connectivity in Extreme Networks,” researchers analyzed detailed data from two separate and extreme terrorist organizations: the Provisional Irish Republican Army, or PIRA, which operated entirely offline from 1970 to 1998, and the Islamic State, or ISIS, which is functioning in the current digital age.

“The PIRA network dataset isn’t only a network of ‘who knows who,’ but it gives the connections between individuals regarding participation in attacks, which require innovation and planning,” Johnson said. “At the same time, we started collecting information online about pro-ISIS supporters. Taking these two datasets together enabled us to do the study.”

For the study, which was published in the journal Science Advances, Johnson and his team monitored individuals on Vkontakte, a social media network based in Russia with more than 350 million users. Pro-ISIS groups normally last longer on Vkontakte than Facebook, which shuts down these groups. The researchers pinned down pro-ISIS followers by using specific social media hashtags displayed in open source information on the internet, and then tracking the groups they belonged to using a software system. On Vkontakte, the researchers uncovered 41,880 individuals in a two-month period, 24,883 of whom were men, and 16,931 women (66 declared no gender).

For the offline portion of the study, the team used a detailed PIRA database, which was easier to assess as the data was previously collected and built as a manual social network listing members, their actions, and demographic information. Of the 1,382 total number of registered PIRA members listed, 1,312 were men and 70 women.

Based on their online and offline research of PIRA and pro-ISIS groups, the researchers demonstrated that although men dominated these groups numerically, women had the most effective connections within the network, acting as a far stronger glue than men in regard to holding the network together, which the study identifies as high “betweenness centrality” (BC).

Pedro Manrique, a postdoctoral associate in the physics department and first author of the study, explains: “A crucial measure in covert networks is related to the capacity of a node (e.g. actor) to serve as a bridge for communications, a flow of resources or ideas, and brokerage. This quantity is called betweenness centrality. An actor with high betweenness centrality is critical to keep the channels of communication active and efficient, and its removal could cause a higher cost and potential risk, to the extent of the disruption of the network.”

The study proposes women in the pro-ISIS groups have a high BC and hence play a central role by passing on vital information, from recruitment messages to files, or video and audio ISIS propaganda. Women in the PIRA network, the study suggests, were inclined to act as team players who spread this team ethic to other members.

One practical finding from the research, Johnson says, is that it suggests authorities investigating extreme networks should engage female members, even if they are the minority and not deemed key figures.

“Our work also feeds into current discussions about the role of women combatants in conflict and terrorism, and how this can differ from stereotypes in which women adopt a minor role,” Johnson said. “I think all this could be of interest in a more general setting as well, beyond physical conflict and terrorism, since our findings suggest a need to reexamine how we judge the importance of any minority group in a network.”

In addition to Johnson and Manrique, other coauthors of the study are UM’s Stefan Wuchty, of the Department of Computer Science; Zhenfeng Cao, Andrew Gabriel, Hong Qi, and Chaoming Song, from the Physics Department; Elvira Restrepo, of the Department of Geography and Global Studies; John Horgan, from Georgia State University’s Global Studies Institute & Department of Psychology; Paul Gill, of the Department of Security and Crime Science, University College London; and Daniela Johnson, of the Department of Government at Harvard University.

 

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Study Examines Sex’s Role in Zika’s Spread

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Study Examines Sex’s Role in Zika’s Spread


By Robert C. Jones Jr.
UM News

Shingui Ruan

Shigui Ruan

CORAL GABLES, Fla. (June 23, 2016)—Before British long jumper Greg Rutherford departs for the Olympic Games in Rio de Janeiro this summer, he’ll leave an important part of himself behind: a sample of his frozen sperm.

Rutherford, whose wife has expressed the desire to have more children, is preserving his sperm as a precautionary measure against Zika, which has swept across more than 30 Latin American and Caribbean countries, with Brazil being hardest hit. Transmitted primarily by the Aedes aegypti mosquito, the virus can also be spread from an infected man to a woman during sex and can cause the severe birth defect known as microcephaly in which infants are born with abnormally small heads and damaged brains.

Few would question Rutherford’s action, but what remains unclear is how much of a role sexual transmission plays in the spread and control of Zika.

Now, in a first-of-its-kind study, a University of Miami researcher and others have created a mathematical model in an attempt to answer that very question.

By itself, Shigui Ruan’s model is not intended to measure the rates of Zika transmission but to delineate the virus’s possible pathways and to help determine which of those transmission routes—either mosquito-borne or sexual transmission—is most important in investigating the spread and control of the virus.

“Zika is a complicated virus,” said Ruan, a professor of mathematics in UM’s College of Arts and Sciences. “It’s not as simple as passing a cold back and forth.”

To build his model, he and his team combined the two modes of transmission into a set of equations, and then calibrated their model to Zika epidemic rates—obtained through the Pan American Health Organization—in Brazil, Colombia, and El Salvador. Using factors such as the biting and mortality rates of the Aedes aegypti and how partners protect themselves during a sexual encounter, the researchers then produced what is called a “basic reproduction number,” essentially the number of infections resulting from one initial infection in a population.

The team found that the average number of new infections that can be traced directly back to a single case of Zika comes out to 2, and that sexual transmission accounts for only 3 percent of new cases.

“Our analyses indicate that the basic reproduction number of Zika is most sensitive to the biting rate and mortality rate of mosquitoes,” said Ruan, “while sexual transmission increases the risk of infection and epidemic size and prolongs the outbreak.”

Their results are published in the journal Scientific Reports.

The model can give epidemiologists and others a good idea of where they should target management efforts, and in this case, mosquito-control measures should remain the most important mitigation strategy to control the virus, said Ruan.

Not that safe sex isn’t important. “It’s a reason to be concerned because on top of mosquito transmission, we now have sexual transmission of the virus,” he explained, noting cases of sexually transmitted Zika in Argentina, Chile, France, Peru, the United States, and other countries.

Zika can stay in semen longer than in blood, though it is not known for how long, the Centers for Disease Control and Prevention reports on its website.

“You could conceivably have somebody who was infected, and didn’t even necessarily know they were infected, carrying the disease around for a while, have some sexual encounter, and infect somebody else,” said Chris Cosner, a University of Miami mathematics professor who has collaborated with Ruan on other studies. “I don’t think it’s been documented. But possibly, in theory, that could result in a source for an outbreak that seems to come from nowhere. So for this particular disease, because of the complexity of the transmission routes and the fact that some people can stay in the infected phase for a long time, it’s more complicated than your average disease.”

Read more about how Ruan and other researchers employ multiple disciplines to study vector-borne diseases.

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