Tech

Bioproduction of chemicals using engineered microorganisms is routinely reported today, but only a few bioprocesses are functional in the large fermentation volumes that industry requires. For a longer period, the lack of successful scale-up has been one of the most important challenges for engineers to solve, in order to replace oil-derived production with biobased production of chemicals.

"One central issue is that bioproduction in large-scale fermenters is limited by toxicities and stresses that allow evolution to reduce or eliminate production of chemicals by engineered cells. This makes it expensive and challenging to commercialize biobased production systems in particular when large amounts of chemicals are needed" says Morten Sommer, Professor and Scientific Director of the Bacterial Synthetic Biology section at the Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark.

A new study made by scientists from the Novo Nordisk Foundation Center for Biosustainability, just published in PNAS, suggests that cells can be engineered to overcome this evolutionary pressure and stably produce high levels of valuable chemicals.

The key is to rewire production cells to only grow when they contain high product concentration. Thus, the evolution can be circumvented and cells will be able to produce the biochemicals within an industrial time scale.

"When we rewire the production microorganism to slow down growth in case it loses production, we efficiently prevent it from performing evolution on the genes leading to production. This allows us to maintain productive cells even when the cells divide to fill up large fermentation tanks," says Peter Rugbjerg, Postdoc at the Novo Nordisk Foundation Center for Biosustainability.

Stops costly evolution

Evolution is beneficial for the cell. However, what is good for the cell may not be good for a biobased process in a fermentation tank. In a fermentation tank evolution can eliminate production - especially during large scale fermentations.

The underlying idea of the new study is to circumvent the evolution occurring in production cells by using a so-called molecular biosensor that senses the product, mevalonate, inside the production cells. The biosensor has the ability to shut down growth if the production concentration declines below a certain point.

This concept is demonstrated by the scientists and can help in driving the development towards a more sustainable society. At this point, microorganisms do not naturally produce high amounts of valuable chemicals, which demands the use of many R&D resources. An expensive process that delays the launch of new biobased processes.

"Engineered, high-level bioproduction of chemicals is not attractive for the cell that tends to grow slower and explore ways to evolve and stop production. This makes it difficult to bridge the gap between research conducted in lab shake flasks and industrial need for large cubic-meter quantities," emphasizes Peter Rugbjerg.

Biomanufacturing becomes a viable alternative

If the findings from the study are broadened out to more production cases, a major obstacle for investing in biobased production is removed. The group at the Novo Nordisk Foundation Center for Biosustainability currently collaborates with biotech companies to investigate and solve the impact of the evolution in current fermentation tanks.

"The biotech industry clearly indicate that they see a great potential in solving this problem. This study can be a step towards more efficient and affordable large-scale biomanufacturing to the benefit of society", says Morten Sommer.

Since 2011, the Novo Nordisk Foundation Center for Biosustainability has been working on developing and perfecting foundational engineering approaches for bio-manufacturing. This study is a splendid example of that.

Link found between autism and damage to proteins in blood plasma

Could lead to earlier diagnosis of the condition

New tests which can indicate autism in children have been developed by researchers at the University of Warwick.

The academic team who conducted the international research believe that their new blood and urine tests which search for damage to proteins are the first of their kind.

The tests could lead to earlier detection of autism spectrum disorders (ASD) and consequently children with autism could be given appropriate treatment much earlier in their lives.

ASDs are defined as developmental disorders mainly affecting social interaction and they can include a wide spectrum of behavioural problems. These include speech disturbances, repetitive and/or compulsive behaviour, hyperactivity, anxiety, and difficulty to adapt to new environments, some with or without cognitive impairment. Since there is a wide range of ASD symptoms diagnosis can be difficult and uncertain, particularly at the early stages of development.

The paper "Advanced glycation endproducts, dityrosine, and arginine transporter dysfunction in autism -- a source of biomarkers for clinical diagnosis" has been published in Molecular Autism. The team was led by Dr Naila Rabbani, Reader of Experimental Systems Biology at the University of Warwick who said: "Our discovery could lead to earlier diagnosis and intervention."

"We hope the tests will also reveal new causative factors. With further testing we may reveal specific plasma and urinary profiles or "fingerprints" of compounds with damaging modifications. This may help us improve the diagnosis of ASD and point the way to new causes of ASD."

The team which is based at the University's Warwick Medical School involves academics at the University of Warwick's Warwick Systems Biology group, the University of Birmingham, the University of Bologna, the Institute of Neurological Sciences, Bologna, and the Don Carlo Gnocchi Foundation ONLUS. They found a link between ASD and damage to proteins in blood plasma by oxidation and glycation - processes where reactive oxygen species (ROS) and sugar molecules spontaneously modify proteins. They found the most reliable of the tests they developed was examining protein in blood plasma where, when tested, children with ASD were found to have higher levels of the oxidation marker dityrosine (DT) and certain sugar-modified compounds called "advanced glycation endproducts" (AGEs).

Genetic causes have been found in 30-35% of cases of ASD and the remaining 65-70% of cases are thought to be caused by a combination of environmental factors, multiple mutations, and rare genetic variants. However the research team also believe that the new tests could reveal yet to be identified causes of ASD.

The team's research also confirmed the previously held belief that mutations of amino acid transporters are a genetic variant associated with ASD.
The Warwick team worked with collaborators at the University of Bologna, Italy, who recruited locally 38 children who were diagnosed as having with ASD (29 boys and nine girls) and a control group of 31 healthy children (23 boys and eight girls) between the ages of five and 12. Blood and urine samples were taken from the children for analysis.

The Warwick team discovered that there were chemical differences between the two groups. Working with a further collaborator at the University of Birmingham, the changes in multiple compounds were combined together using artificial intelligence algorithms techniques to develop a mathematical equation or "algorithm" to distinguish between ASD and healthy controls. The outcome was a diagnostic test better than any method currently available.

The next steps are to repeat the study with further groups of children to confirm the good diagnostic performance and to assess if the test can identify ASD at very early stages, indicate how the ASD is likely to develop further to more severe disease and assess if treatments are working.

WASHINGTON, D.C., February 18, 2018 -- Circadian clocks are found within microbes and bacteria, plants and insects, animals and humans. These clocks arose as an adaptation to dramatic swings in daylight hours and temperature caused by the Earth's rotation. But we still don't fully understand how these tiny biological clocks work.

During the 62nd Biophysical Society Annual Meeting, held Feb. 17-21, in San Francisco, California, Andy LiWang at the University of California, Merced will present his lab's work studying the circadian clock of blue-green colored cyanobacteria. One type of cyanobacteria, called spirulina, is high in vitamins and minerals and is used as a natural food dye for candy and gum.

LiWang's group discovered that how the proteins move hour by hour is central to cyanobacteria's circadian clock function. "And now it's becoming clear that the same is true for eukaryotic [animal] clocks," LiWang said.

Cyanobacterial circadian clock proteins are unique because they can be reconstituted within a test tube in the absence of live cells. Researchers made a solution of these proteins and adenosine triphosphate (ATP), food for the proteins, to create a circadian clock that functioned for weeks.

LiWang's structural biology lab uses nuclear magnetic resonance (NMR) spectroscopy, the parent technology for MRI, to study the protein structure and dynamics of biological molecules and then uses the structures to gain insights into their function. "We also examine how the proteins wiggle, flex, and shape-shift, because these motions ... are also critical to their biological function," LiWang said.

LiWang's lab also collaborates with X-ray crystallographers like Carrie Partch at the University of California, Santa Cruz, because X-ray crystallography is a powerful technique to capture static structures of proteins and their complexes at atomic and near-atomic resolution.

"A big surprise for us was the extent to which internal motions of circadian clock proteins dictate ... their function," LiWang said. "Static X-ray crystal structures of individual proteins, mostly solved by other labs, were invaluable to our work but told only part of the story."

Cyanobacterial clock proteins aren't exactly the same as the clock proteins of animals or human clocks, but proteins serve as the cogs, gears and springs of all circadian clockworks and the overall function of the proteins is similar.

"Because clock proteins need to keep time, there should be some basic principles of biological timekeeping shared between all clocks regardless of whether the proteins are the same or not," LiWang said. "Our structures of the complexes of the circadian clock proteins of cyanobacteria provided important mechanistic insights, but are static snapshots of a system that's continuously moving and changing hour by hour," said LiWang.

WASHINGTON, D.C., February 18, 2018 -- Cell division is an intricately choreographed ballet of proteins and molecules that divide the cell. During mitosis, microtubule-organizing centers (MTOCs) assemble the spindle fibers that separate the copying chromosomes of DNA. While scientists are familiar with MTOCs' existence and the role they play in cell division, their actual physical structure remains poorly understood.

Shruthi Viswanath, a postdoctoral scholar at the University of California, San Francisco, with a team of researchers, is trying to decipher the molecular architecture of the MTOC. They will present their work during the 62nd Biophysical Society Annual Meeting, held Feb. 17-21, in San Francisco, California.

MTOCs are specially designed structures within the cell that create, anchor and stabilize the network of microtubules that act like scaffolding within the cell. More than 1,000 proteins are associated with the MTOC in animal cells, but few of these proteins have been assigned a particular function.

Rather than untangle the complexity of the MTOC, Viswanath focused her research on yeast cells. Within these simpler organisms, the spindle pole body (SPB) functions like the MTOC. Unlike in animal cells, the SPB of yeast contains only 18 proteins and Viswanath has initially focused on five core proteins: Spc110, Spc42, Cnm67, Spc29 and Cmd1.

Using multiple techniques such as structural modeling, X-ray scattering, X-ray crystallography and electron microscopy, Viswanath and her team found that the Spc110 protein provides a greater function in the SPB than originally believed. At first, scientists thought these proteins acted as mere spacers holding pieces of the SPB architecture in place, but now it is believed these proteins may provide a binding surface for this architecture. This information can help understand the function of the human cell equivalent of SPBs called centrosomes. Cancer cells in most forms of cancer reveal abnormalities in the size or structure of centrosomes. Future experiments are necessary to identify the position of other key proteins, like Spc29, a critical protein in the SPB core and to eventually identify its specific function.

Focusing on their personal DNA and genealogies, middle school students appear to have learned as much as their peers who used case studies, according to a Penn State researcher.

"We noticed that both groups got the content, but once all was said and done, the case study group would have preferred to do the work on themselves," said Elizabeth Wright, postdoctoral scholar working with Nina Jablonski, Evan Pugh Professor of Anthropology, Penn State.

During the two-week camp held at Penn State, the University of South Carolina and the American Museum of Natural History, middle school scientists tried to answer the question "Who am I?" The camp included instruction and investigation in the topics of personal DNA family genealogy, anthropology, health and evolution. Wright, a former middle school science teacher with seven years classroom experience, who worked with high school students for her doctorate in curriculum and instruction in science education at the University of Washington, designed the curriculum for the camp.

She presented preliminary findings of research done to find out the efficacy of the curriculum with respect to student learning and interest today (Feb 17) at the annual meeting of the American Association for the Advancement of Science in Austin, Texas.

Three sets of campers focused on their personal family histories and DNA while another group used case study data. A fifth group was the basis of an online video series "Finding Your Roots: The Seedlings" produced by WPSU and also available on the PBS "Finding Your Roots" classroom page.

"The initial data support our hypothesis that middle school students prefer learning about themselves," said Wright. "While learning gains were the same between the personal and case study camps, as soon as the case study campers had the opportunity to do personalized research, most campers took it."

"We already see that they are taking what they are learning and taking it back to schools," said Wright. "One camper who never spoke up in science class before the summer camp wasn't happy with the science electives being offered in her school, so she proposed a one-on-one independent study course and got it done. Another young woman took our curriculum, modified it to meet the needs of elementary students, and led a three-day camp in Atlanta this summer."

While the study wanted to look at an educational intervention to encourage engagement with science and perhaps even pursuit of science, another aspect was inevitable. The students for the study were chosen to be a diverse sample who were not necessarily science enthusiasts. Looking at genetics and genealogy, the subject of race was certain to come up.

"Many teachers are white women," said Wright. "We don't always have shared experiences. I don't know what it is like to be a 14-year-old boy of African-American descent. I don't know what it's like to be a 16-year-old immigrant from Guatemala."

As a teacher, Wright noted that talking about race is not comfortable and teachers can become lost if they have not already thought about race.

"The camp curriculum frames race as a biological, reality and biologically speaking, skin color -- the amount of melanin in one's skin -- serves an important role in survival to reproduction, but it is also a lived experience. If we don't address both realities, we do students a disservice."

Which does not mean that there are not some very uncomfortable moments.

"One 10-year-old stared at the screen with his genetic ancestry on it," said Wright. "Then he said, 'The only reason I have any European in me is because one of my ancestors was raped.'"

Wright acknowledged that this was very likely the case. She asked him to also consider the possibility that there may have been a consensual, loving relationship, but conceded to the child that he was probably correct.

"As uncomfortable as it is, as educators we can't walk back from that truth," said Wright. "As a society, as individuals, we have no hope of fixing any of our collective issues if we don't have this conversation."

Besides an understanding of the scientific basics, the campers learned other things. According to Wright, regardless of whether they were dark-skinned or light-skinned, campers were all willing to listen. When a 13-year-old dark-skinned boy spoke of never going into the corner market without being tracked, white children who had never experienced this became frustrated and angry and became advocates.

"What could we do if these young scientists were available for months?" said Wright.

No camper was left out. Even if a child was adopted and had no idea of their biological parentage, their DNA data would point them to a geographic location from which they came. Campers were encouraged to explore those cultures and perhaps incorporate some of them into their lives.

A unique part of the camp experience was time set aside for the young scientists to do their own research. One camper explored the effects of ultraviolet radiation on lumbriculus worms. Another looked into the relationship of human and canine DNA.

One camper, a gifted artist, created a genealogical tree of anime characters. Various anime-type traits -- both recessive and dominant -- were assigned to characters and inherited down the line. The tree came complete with drawings of the anime characters and their respective traits.

"She clearly understood the concepts," said Wright. "Although it wasn't a traditional inheritance tree, there were traits and they were passed on, showing heterozygosity or homozygosity."

The summer camp curriculum is intended to be a portion of a middle school curriculum. Other researchers are working on modules for undergraduate college students and testing the results at Spelman College and Morehouse College.

Henry Louis Gates Jr., PBS "Finding Your Roots" show host and Alphonse Fletcher Jr. University Professor, Harvard University, is a collaborator on the project. He is also director of Harvard's Hutchins Center for African & African American Research.

A groundbreaking new wearable designed to be worn on the throat could be a game-changer in the field of stroke rehabilitation.

Developed in the lab of Northwestern University engineering professor John A. Rogers, in partnership with Shirley Ryan AbilityLab, the sensor is the latest in Rogers' growing portfolio of stretchable electronics that are precise enough for use in advanced medical care and portable enough to be worn outside the hospital, even during extreme exercise.

Rogers will present research on the implications of stretchable electronics for stroke recovery treatment at a press briefing at 11a.m. CST, Saturday, Feb. 17, at the American Association for the Advancement of Science (AAAS) annual meeting in Austin, Texas. The briefing, "Biomedical Sensors in Service of Society," will be held at 11 a.m. CST in Room 6, Level 3 of the Austin Convention Center.

Rogers also will discuss his work at the AAAS presentation "Soft Electronics for the Human Body" from 4:30 to 5 p.m. CST Feb. 17, at the AAAS meeting. Rogers' talk, to be held in Room F of the Austin Convention Center, is part of the scientific session "Biomedical Sensors: Advances in Health Monitoring and Disease Treatment."

Rogers' sensors stick directly to the skin, moving with the body and providing detailed health metrics including heart function, muscle activity and quality of sleep.

"Stretchable electronics allow us to see what is going on inside patients' bodies at a level traditional wearables simply cannot achieve," Rogers said. "The key is to make them as integrated as possible with the human body."

Rogers' new bandage-like throat sensor measures patients' swallowing ability and patterns of speech. The sensors aid in the diagnosis and treatment of aphasia, a communication disorder associated with stroke.

The tools that speech-language pathologists have traditionally used to monitor patients' speech function - such as microphones - cannot distinguish between patients' voices and ambient noise.

"Our sensors solve that problem by measuring vibrations of the vocal chords," Rogers said. "But they only work when worn directly on the throat, which is a very sensitive area of the skin. We developed novel materials for this sensor that bend and stretch with the body, minimizing discomfort to patients."

Shirley Ryan AbilityLab, a research hospital in Chicago, uses the throat sensor in conjunction with electronic biosensors - also developed in Rogers' lab - on the legs, arms and chest to monitor stroke patients' recovery progress. The intermodal system of sensors streams data wirelessly to clinicians' phones and computers, providing a quantitative, full-body picture of patients' advanced physical and physiological responses in real time.

"One of the biggest problems we face with stroke patients is that their gains tend to drop off when they leave the hospital," said Arun Jayaraman, research scientist at the Shirley Ryan AbilityLab and a wearable technology expert. "With the home monitoring enabled by these sensors, we can intervene at the right time, which could lead to better, faster recoveries for patients."

Because the sensors are wireless, they eliminate barriers posed by traditional health monitoring devices in clinical settings. Patients can wear them even after they leave the hospital, allowing doctors to understand how their patients are functioning in the real world.

"Talking with friends and family at home is a completely different dimension from what we do in therapy," said Leora Cherney, research scientist at the Shirley Ryan AbilityLab and an expert in aphasia treatment. "Having a detailed understanding of patients' communication habits outside of the clinic helps us develop better strategies with our patients to improve their speaking skills and speed up their recovery process."

Jayaraman describes the platform's mobility as a "gamechanger" in rehabilitation outcomes measurement.

Data from the sensors will be presented in a dashboard that is easy for both clinicians and patients to understand. It will send alerts when patients are underperforming on a certain metric and allow them to set and track progress toward their goals.

"We are so grateful for our partnership with the Shirley Ryan AbilityLab," Rogers said. "They are helping us move our technology from the research lab to the real world, where it already is making a positive impact on the lives of patients."

Rogers also is collaborating with the Shirley Ryan AbilityLab to test the sensors on patients with other conditions, such as Parkinson's disease.

Ten Northwestern professors will present their work at the AAAS annual meeting. See a full summary at Northwestern Now.

A new ultrathin, elastic display that fits snugly on the skin can show the moving waveform of an electrocardiogram recorded by a breathable, on-skin electrode sensor. Combined with a wireless communication module, this integrated biomedical sensor system - called "skin electronics" - can transmit biometric data to the cloud.

This latest research by a Japanese academic-industrial collaboration, led by Professor Takao Someya at the University of Tokyo's Graduate School of Engineering, is slated for a news briefing and talk at the AAAS Annual Meeting in Austin, Texas on February 17th.

Thanks to advances in semiconductor technology, wearable devices can now monitor health by first measuring vital signs or taking an electrocardiogram, and then transmitting the data wirelessly to a smartphone. The readings or electrocardiogram waveforms can be displayed on the screen in real time, or sent to either the cloud or a memory device where the information is stored.

The newly-developed skin electronics system aims to go a step further by enhancing information accessibility for people such as the elderly or the infirm, who tend to have difficulty operating and obtaining data from existing devices and interfaces. It promises to help ease the strain on home healthcare systems in aging societies through continuous, non-invasive health monitoring and self-care at home.

The new integrated system combines a flexible, deformable display with a lightweight sensor composed of a breathable nanomesh electrode and wireless communication module. Medical data measured by the sensor, such as an electrocardiogram, can either be sent wirelessly to a smartphone for viewing or to the cloud for storage. In the latest research, the display showed a moving electrocardiogram waveform that was stored in memory.

The skin display, developed by a collaboration between researchers at the University of Tokyo's Graduate School of Engineering and Dai Nippon Printing (DNP), a leading Japanese printing company, consists of a 16 x 24 array of micro LEDs and stretchable wiring mounted on a rubber sheet.

"Our skin display exhibits simple graphics with motion," says Someya. "Because it is made from thin and soft materials, it can be deformed freely."

The display is stretchable by as much as 45 percent of its original length.

It is far more resistant to the wear and tear of stretching than previous wearable displays. It is built on a novel structure that minimizes the stress resulting from stretching on the juncture of hard materials, such as the micro LEDs, and soft materials, like the elastic wiring - a leading cause of damage for other models.

It is the first stretchable display to achieve superior durability and stability in air, such that not a single pixel failed in the matrix-type display while attached snugly onto the skin and continuously subjected to the stretching and contracting motion of the body.

The nanomesh skin sensor can be worn on the skin continuously for a week without causing any inflammation. Although this sensor, developed in an earlier study, was capable of measuring temperature, pressure and myoelectricity (the electrical properties of muscle), it successfully recorded an electrocardiogram for the first time in the latest research.

The researchers applied tried-and-true methods used in the mass production of electronics - specifically, screen printing the silver wiring and mounting the micro LEDs on the rubber sheet with a chip mounter and solder paste commonly used in manufacturing printed circuit boards. Applying these methods will likely accelerate the commercialization of the display and help keep down future production costs.

DNP is looking to bring the integrated skin display to market within the next three years by improving the reliability of the stretchable devices through optimizing its structure, enhancing the production process for high integration, and overcoming technical challenges such as large-area coverage.

"The current aging society requires user-friendly wearable sensors for monitoring patient vitals in order to reduce the burden on patients and family members providing nursing care," says Someya. "Our system could serve as one of the long-awaited solutions to fulfill this need, which will ultimately lead to improving the quality of life for many."

Musee national Picasso-Paris and the Northwestern University/Art Institute of Chicago Center for Scientific Studies in the Arts (NU-ACCESS) have completed the first major material survey and study of the Musee national Picasso-Paris' world-renowned Pablo Picasso bronzes using cutting-edge, portable instruments.

The international research team of scientists, art conservators and curators used the portable instruments and a robust database of alloy "fingerprints" to non-invasively analyze a priceless group of 39 bronzes (cast between 1905 and 1959) and 11 painted sheet metal sculptures (from the 1960s) in the Musee national Picasso-Paris' collection.

The researchers were able to trace five bronzes cast in Paris during World War II to the foundry of Emile Robecchi, a lesser-known collaborator of Picasso's. They also discovered Robecchi's alloy compositions varied significantly during 1941 and 1942, likely reflecting the challenging circumstances of the Nazi occupation of Paris. In their study of Picasso's cast-iron sheet metal sculptures, the researchers are the first to report the use of silver for facial features in a work inspired by one of his wives.

Francesca Casadio, the Grainger Executive Director of Conservation and Science at the Art Institute and co-director of NU-ACCESS, will discuss the findings at a Feb. 17 press briefing at the American Association for the Advancement of Science (AAAS) annual meeting in Austin, Texas. The briefing, "Technology Peers Into Picasso's Art," will be held at 9 a.m. CST in Room 6, Level 3, of the Austin Convention Center.

[EDITOR'S NOTE: A separate study of Picasso's art and methods will be discussed at the same press briefing. Marc Walton, co-director of NU-ACCESS and a materials scientist at Northwestern, will talk about a study of Picasso's Blue Period painting "La Miséreuse accroupie" (The Crouching Woman, 1902). Using a scanning elemental analyzer developed by the center, the researchers uncovered buried images with connections to other works by Picasso as well as another painting -- likely by another Barcelona painter -- whose forms Picasso used to inform some parts of his own final composition.]

"Our project highlights the value of cutting-edge scientific tools and international collaborations in advancing discoveries in art," Casadio said. "It was exciting to partner with Virginie Perdrisot, curator of the Musee national Picasso-Paris, to unlock the material composition and technical details of Picasso's creative process. We now can begin to write a new chapter in the history of this prolific giant of modern art."

The NU-ACCESS team included Casadio and three scientists from Northwestern. Emeline Pouyet, a materials scientist and NU-ACCESS postdoctoral fellow, created the diagram of bronze compositions over which Picasso's production could be mapped. With their portable instruments, which use X-ray fluorescence spectrometry, the researchers could easily analyze the priceless objects in the museum galleries and in storage, without the need to move them.

Using non-invasive analysis of elements at a work's surface, NU-ACCESS has amassed the world's largest art database of alloy "fingerprints" for early 20th-century fine arts bronzes. More than a decade in the making, the database includes data on 350 works of art by the leading artists that came to Paris from all over the world to achieve the finest casts of their bronzes. This data is key to NU-ACCESS's "elemental fingerprinting" technique.

The researchers used this technique to analyze the alloys in the Picasso bronzes for clues about how, when and where they were cast.

Scientific analysis of the metal alloys of the bronze sculptures, coupled with recently discovered archival information, revealed that five of Picasso's 1941 and 1942 casts without a foundry mark were made by Robecchi's foundry. One of these sculptures is "Head of a Woman, in Profile" (modeled 1931, cast 1941).

The study provides provenance for these works and helps define the activities of Picasso and the Robecchi foundry during war times. (For the bronzes cast in the 1940s by Robecchi, Picasso first modeled the works in the 1930s in plaster.)

"In the context of increased material studies of Picasso's painting practices, our study extends the potential of scientific investigations to the artist's three-dimensional productions," Pouyet said. "Material evidence from the sculptures themselves can be unlocked by scientific analysis for a deeper understanding of Picasso's bronze sculpture-making process and the history of artists, dealers and foundrymen in the production of modern sculpture."

The researchers also discovered that in this short two-year period during World War II, the composition of the alloy used by Robecchi varied significantly -- possibly because of the scarcity of raw metals, German appropriation of non-ferrous metals for the war efforts and re-use of scrap metal from brass objects of ordinary use. This work was done in partnership with the Musee national Picasso-Paris staff and Clare Finn, a private conservator in London and an expert on the dynamics of fine arts castings during World War I and World War II.

Picasso made a relatively small number of sculptures (approximately 700, roughly one-sixth of his output in paintings) and issued few numbered editions of his bronzes, Casadio said. The circumstances of much of his early production as well as that of the sculptures cast during World War II have been unclear. Many of the bronzes analyzed by the NU-ACCESS team are unique casts.

In its analysis of Picasso's sheet metal sculptures, the research team is the first to discover the use of the precious metal silver to render the details of the hair, eyes and other facial features on the cast-iron sheet, polychrome sculpture titled "Head of a Woman" (late 1962). The artist's second wife, Jacqueline Roque, inspired the piece.

Analysis also sheds light on the productive relationship of Picasso with craftsmen in a workshop in the south of France. For this project, Ludovic Bellot-Gurlet, a molecular spectroscopist in Paris who has developed a mobile lab for paint and pigment analysis, worked side by side with NU-ACCESS scientists and their elemental analysis tools. They figuratively peeled back layers of paint to uncover what paintwork was done by Picasso to the sheet metal sculptures and what was applied by the workshop.

In addition to the press briefing, Casadio also will discuss the findings at 2 p.m. CST Feb. 17 in Room 17B of the Austin Convention Center. Her presentation, "Analyzing Picasso: Recent Breakthroughs Thanks to Mobile Instrumentation," is part of a scientific session co-organized by Casadio and Walton called "Analyzing Picasso: Scientific Innovation, Instrumentation and Education." Casadio will be joined at the session by two Northwestern speakers discussing different aspects of Picasso's work. (See details below).

AUSTIN - (Feb. 16, 2018) - Scientists have successfully used gene editing to repair 20 to 40 percent of stem and progenitor cells taken from the peripheral blood of patients with sickle cell disease, according to Rice University bioengineer Gang Bao.

Bao, in collaboration with Baylor College of Medicine, Texas Children's Hospital and Stanford University, is working to find a cure for the hereditary disease. A single DNA mutation causes the body to make sticky, crescent-shaped red blood cells that contain abnormal hemoglobin and can block blood flow in limbs and organs.

In his talk at the annual American Association for the Advancement of Science meeting in Austin today, Bao revealed results from a series of tests to see whether CRISPR/Cas9-based editing can fix the mutation. His presentation was part of a scientific session titled "Gene Editing and Human Identity: Promising Advances and Ethical Challenges."

"Sickle cell disease is caused by a single mutation in the beta-globin gene (in the stem cell's DNA)," he said. "The idea is to correct that particular mutation, and then stem cells that have the correction would differentiate into normal blood cells, including red blood cells. Those will then be healthy blood cells."

Bao's lab collaborated with Vivien Sheehan, an assistant professor of pediatrics and hematology at Baylor and a member of the sickle cell program at Texas Children's, to collect stem and progenitor cells (CD34-positive cells) from patients with the disease. These were then edited in the Bao lab with CRISPR/Cas9 together with a custom template, a piece of DNA designed to correct the mutation.

The gene-edited cells were injected into the bone marrow of immunodeficient mice and tested after 19 weeks to see how many retained the edit. "The rate of repair remained stable, which is great," Bao said. This engraftment study was carried out in the lab of Matt Porteus, an associate professor of pediatrics at Stanford.

Another major finding of the study is that the CRISPR/Cas9 system could introduce large alterations to the genes in patients' cells, in addition to small mutations or deletions. These off-target effects could cause a disease.

The findings, part of an upcoming paper, are a step toward treating sickle cell disease. Obstacles in the way of a cure include optimizing the CRISPR/Cas9 system to eliminate off-target effects, as well as finding a way to further increase the amount of gene-corrected stem cells.

Bao pointed out that researchers still don't know whether repairing as much as 40 percent of the cells is enough to cure a patient. "We'd like to say, 'Yes,'" he said, "but we don't really know yet. That's something we hope to learn from an eventual clinical trial."

Bao is Rice's Foyt Family Professor of Bioengineering.

Bird-human actions can end in tragedy -- for bird as well as human.

John Swaddle believes technology and a solid understanding of bird behavior can make those tragedies less frequent.

Swaddle is a behavioral biologist at William & Mary. He briefed attendees at the annual meeting of the American Association for the Advancement of Science on developments in a pair of initiatives designed to minimize unpleasant results of bird-human interactions.

The story of bird-meets-human too often ends in tragedy, he said. Birds descend on ripening crops, increasing the prevalence of human hunger and even starvation. At the same time, birds are killed by flying into buildings, cell towers and wind turbines. Bird strikes to aircraft can be deadly for both human and bird.

The two initiatives use acoustic deterrence to mitigate the human-bird tragedy. Both Sonic Nets and Acoustic Lighthouse make use of technologically advanced hardware. But Swaddle stresses that each project rests on the conceptual bedrock of a thoroughly researched understanding of bird behavior.

"The fundamental knowledge of how birds behave and respond to sound helps us derive these new technologies and solutions," Swaddle said. He discussed the two projects in a session titled Applying Insights from Animal Behavior to Address Global Challenges.

Sonic Nets uses sound to make gathering birds uncomfortable enough to leave an area where birds are not wanted. It's a proven technology, currently in use in a number of locations where birds have been a problem. Acoustic Lighthouse is the newer of the two ideas, aimed at reducing the number of birds that die from collisions with human-built structures.

A 2017 paper in the journal Integrative and Comparative Biology by Swaddle and former William & Mary graduate student Nicole Ingrassia demonstrated proof of concept for the Acoustic Lighthouse idea.

Swaddle said death by wind turbine claims millions of birds each year. If you add in the birds colliding with cell towers, tall buildings and other products of modern life, the count goes up to billions.

"We know that there's a risk to bird populations. That risk is not evenly spread across the world. It's concentrated in certain areas, because wind is concentrated in certain areas," Swaddle said. "That's where the wind turbines are -- and that's where bird movement are sometimes concentrated, especially during migration."

Virginia is an excellent case study site, and William & Mary is located in the Eastern Flyway, a major bird migration route with endpoints in the Arctic and the tropics. It's also prime siting for wind turbines.

"There's a lot of interest in developing near-shore or offshore wind energy. Putting large, rotating structures that look like mincemeat-makers in the sky isn't going to be good for the birds," Swaddle said.

The idea behind Acoustic Lighthouse is simple: get flying birds to look up. Swaddle explained that a bird in flight aligns its body in a horizontal plane for optimum aerodynamics. Plus, most birds have eyes located on the sides of their skulls. These anatomical facts of life means a migrating bird is looking down, and not where it's flying.

When downward-looking bird meets immovable object, the bird never knows what it hit. Swaddle says many people will pick up a window-strike victim, see the wobbling head and render a verdict of broken neck. In reality, the birds are much more likely to have suffered immediate, fatal brain injury, he said.

Acoustic Lighthouse technology consists of a directional speaker mounted on a wind turbine or other structure. The speaker projects a sound that alerts approaching birds and prompts them to slow down, look ahead -- and fly around the turbine or tower.

Swaddle said cruising birds slow down just like birds in cartoons, lowering their tail feathers to force their body from the horizontal plane to a more vertical position.

"All that's missing is the brake-screeching sound," he said. A slowing bird's altered posture will naturally cause it to look up, see danger ahead and alter course -- once it hears the signal.

"It's a bit like someone texting while they're driving," he said. "If you honk your horn at them, they'll look up."

The second technology Swaddle discussed, Sonic Nets, was developed as part of a collaboration that includes Mark Hinders of the William & Mary Department of Applied Science. Sonic Nets is more fully developed technology that received early-stage funding from the Bill & Melinda Gates Foundation through its Grand Challenges Explorations program.

Sonic Nets, like Acoustic Lighthouse, uses focused sound from directional speakers to modify bird behavior, but the projects are different in many respects. Acoustic Lighthouse is for flying birds, but Sonic Nets is designed for problems that stem from gatherings of birds.

The Sonic Nets speakers project a sound that is designed to disrupt the chatter of gathering birds. Swaddle explained that flocking birds rely on each other to keep watch for danger. The "pink noise" emitted by Sonic Nets masks the avian chatter, making the birds unable to hear predator cues and alarm calls which causes birds to leave the fields of ripening crops, parking lot, airport or any other area where Sonic Nets is deployed.

"The idea is that we're broadcasting sounds that maximally interfere with the way birds communicate with each other," Swaddle said. "If birds can't talk to each other, their perception of the threat of the area -- the predation risk -- goes way up. So birds don't like being in that area."

In terms of danger avoidance, Sonic Nets offers birds the equivalent or humans choosing to go down a well-lighted road over a dark alleyway, Swaddle says. The birds are choosing to go to a place that's not acoustically busy.

Sonic Nets is being commercialized through a partnership with Midstream Technology. A number of Sonic Nets installations have been deployed on three continents.

"We've gone all the way to full commercialization and we seem to be having particular success with agriculture," Swaddle said. "We have shown in lab and field that the sound displaces birds from that area and, importantly, seems to save a long-lasting effect. Habituation has been a continuous bugbear of the bird-deterrent industry but we don't have that issue with Sonic Nets because we are manipulating the real threat of predation in the area."

Multicellular organisms like ourselves depend on a constant flow of information between cells, coordinating their activities in order to proliferate and differentiate. Deciphering the language of intercellular communication has long been a central challenge in biology. Now, Caltech scientists have discovered that cells have evolved a way to transmit more messages through a single pathway, or communication channel, than previously thought, by encoding the messages rhythmically over time.

The work, conducted in the laboratory of Michael Elowitz, professor of biology and bioengineering, Howard Hughes Medical Institute Investigator, and executive officer for Biological Engineering, is described in a paper in the February 8 issue of Cell.

In particular, the scientists studied a key communication system called "Notch," which is used in nearly every tissue in animals. Malfunctions in the Notch pathway contribute to a variety of cancers and developmental diseases, making it a desirable target to study for drug development.

Cells carry out their conversations using specialized communication molecules called ligands, which interact with corresponding molecular antennae called receptors. When a cell uses the Notch pathway to communicate instructions to its neighbors--telling them to divide, for example, or to differentiate into a different kind of cell--the cell sending the message will produce certain Notch ligands on its surface. These ligands then bind to Notch receptors embedded in the surface of nearby cells, triggering the receptors to release gene-modifying molecules called transcription factors into the interior of their cell. The transcription factors travel to the cell's nucleus, where the cell's DNA is stored, and activate specific genes. The Notch system thus allows cells to receive signals from their neighbors and alter their gene expression accordingly.

Ligands prompt the activation of transcription factors by modifying the structure of the receptors into which they dock. All ligands modify their receptors in a similar way and activate the same transcription factors in a receiving cell, and for that reason, scientists generally assumed that the receiving cell should not be able to reliably determine which ligand had activated it, and hence which message it had received.

"At first glance, the only explanation for how cells distinguish between two ligands, if at all, seems to be that they must somehow accurately detect differences in how strongly the two ligands activate the receptor. However, all evidence so far suggests that, unlike mobile phones or radios, cells have much more trouble precisely analyzing incoming signals," says lead author and former Elowitz lab graduate student Nagarajan (Sandy) Nandagopal (PhD '18). "They are usually excellent at distinguishing between the presence or absence of signal, but not very much more. In this sense, cellular messaging is closer to sending smoke signals than texting. So, the question is, as a cell, how do you differentiate between two ligands, both of which look like similar puffs of smoke in the distance?"

Nandagopal and his collaborators wondered whether the answer lay in the temporal pattern of Notch activation by different ligands--in other words, how the "smoke" is emitted over time. To test this, the team developed a new video-based system through which they could record signaling in real time in each individual cell. By tagging the receptors and ligands with fluorescent protein markers, the team could watch how the molecules interacted as signaling was occurring.

The team studied two chemically similar Notch ligands, dubbed Delta1 and Delta4. They discovered that despite the ligands' similarity the two activated the same receptor with strikingly different temporal patterns. Delta1 ligands activated clusters of receptors simultaneously, sending a sudden burst of transcription factors down to the nucleus all at once, like a smoke signal consisting of a few giant puffs. On the other hand, Delta4 ligands activated individual receptors in a sustained manner, sending a constant trickle of single transcription factors to the nucleus, like a steady stream of smoke.

These two patterns are the key to encoding different instructions to the cell, the researchers say. In fact, this mechanism enabled the two ligands to communicate dramatically different messages. By analyzing chick embryos, the authors discovered that Delta1 activated abdominal muscle production, whereas Delta4 strongly inhibited this process in the same cells.

"Cells speak only a handful of different molecular languages but they have to work together to carry out an incredible diversity of tasks," says Elowitz. "We've generally assumed these languages are extremely simple, and cells can basically only grunt at each other. By watching cells in the process of communicating, we can see that these languages are more sophisticated and have a larger vocabulary than we ever thought. And this is probably just the tip of an iceberg for intercellular communication."

Marit Bjoergen is a Norwegian cross-country skier who has won six Olympic gold medals, 18 World Championship gold medals and 110 World Cup victories. The 37-year old is competing in the 2018 Olympics in PyeongChang and is already the most decorated female Winter Olympian ever.

Wouldn't it be fun to peek behind the curtains to know how she trains? A team of researchers from the Norwegian University of Science and Technology and Nord University has done just that.

Marit Bjoergen openly shared all of her training information with researchers Guro Solli, a PhD candidate at the Norwegian University of Science and Technology (NTNU) and Nord University, Dr. Espen Tønnessen from the Norwegian Olympic Federation and Professor Øyvind Sandbakk from NTNU's Centre for Elite Sports Research. A summary of what the researchers found has recently been published in Frontiers in Physiology.

"Marit Bjoergen is a unique athlete, she is the most successful female winter Olympian ever and has an interesting training history," said Solli, who is analysing Bjoergen's training data for her dissertation. "She has experimented with different training models. And she wanted to help future athletes and coaches by sharing her knowledge and training data."

Unprecedented access

Bjoergen, of course, didn't just appear out of nowhere as a successful cross-country skier. She grew up on a farm in central Norway, and started racing at age 7. She told NRK, the Norwegian Broadcasting Corporation, she didn't lose a race until she turned 13.

She started racing on the world circuit at age 19, with the ups and downs you might expect as a young athlete learns how to harness her talent. Her biggest years were from 2010-2015.

From the time Bjoergen turned 20, she kept daily training diaries and underwent physiological tests to determine different fitness measures, such as her maximal oxygen consumption and her speed at her anaerobic threshold, both of which are considered important factors for performance in endurance sports.

"There aren't that many publications that report on the longitudinal training process of world-class athletes," Sandbakk said. "Case studies allow us to investigate every aspect of training in detail and expand our understanding of the mechanisms behind the development of high performance."

Sandbakk points out that one of the most important finding from the recent study was how Bjoergen gradually increased her training load in the years before her most successful period, during which she trained 940 hours per year.

"This supports previous findings that highlight the importance of athletes putting in a lot of hours of training if they want to succeed in endurance sports," he said.

The researchers also provided detailed information about how Bjoergen trained at altitude and how she tapered her training in the final weeks before major championships.

A focus on five successful years

All told, the researchers looked at 8105 of Bjoergen's training sessions from 2000 to 2017, of which 7642 were workouts and 463 were competitions.

This provided the researchers important context for their analysis of Bjoergen's five most successful years (from May 2010 to April 2015).

During this period, Bjoergen won 63 individual World Cup victories, two gold medals at the 2014 Olympics and seven gold medals in three World Championships.

So beyond raw talent and determination, what's her secret?

Lots of hours, lots of endurance training

First of all, Solli said, Bjoergen trained a lot --a total of 13600 hours during the 17 years the researchers investigated.

"This is an average training volume of 70 hours a month and 15 hours a week" over nearly two decades, Solli said. "This long-term continuity of high training loads combined with her high performance is unique."

Additionally, Bjoergen was very careful in how she built up her capacity to train, Solli said.

"She went from around 500 hours per year as a young racer up to around 700 hours at the time she won her first gold medal at age 23," she said. "She then increased her training to 940 hours a year during her five most successful years from when she was 30 to 35 years old."

Most of her workout time-- 91 %, or about 850 hours on average -- was spent in endurance training. Eight percent of her training was strength training, with just 1 % of her time spent in speed training.

That division between different training intensities is all the more striking when you realize that Bjoergen has won not only long-duration ski races of 30 km, but also relays and sprints which require explosive speed and power.

"Both cross-country skiing training and competitions involve varied terrain and the use of different techniques, including large fluctuations in speed and a varying load on the upper and lower body," Sandbakk said. "Skiers also have to train differently in the summer by running, roller skiing and cycling because there is no snow. That makes a cross-country skier's training a sophisticated puzzle of training sessions of different forms, intensities and organization."

Most sessions were nearly an hour long or longer

During the period the researchers focused on, Bjoergen performed 76 % of her endurance training sessions at a low intensity, which the researchers defined as between 60 and 87% of her maximal heart rate.

While her training intensity might have been low, the number of hours she spent working out at this intensity is impressive. Just 4 % of these low intensity sessions were under 50 minutes long, while 42 % were between 50-90 minutes and 23 % were more than 150 minutes long.

Another 7% of her endurance sessions were at moderate intensity, or at 87-92 % of her maximal heart rate, typically performed as interval sessions where Bjoergen repeated five intervals of 7-to-8 minute periods, with 1-2 minutes of rest in between each interval.

The remaining 17 % of her sessions were performed at high intensity, with a heart rate over 92% of maximum. These sessions were typically either interval training or competitions. Her most typical high-intensity interval session was composed of five workout intervals of 4-5 minutes with 2-3 minutes of rest in between.

This changed, of course, during the annual competition season, with Bjoergen logging more long duration sessions during the preparation period and shorter sessions during the competition phase.

An early focus on high-intensity training

Bjoergen's focus on low-intensity training was in contrast to the years before her most successful period, were she focused more on high-intensity training, Solli said. At this time, she relied on a very high number of high-intensity sessions during concentrated periods.

Solli said this early period with lots of high-intensity sessions led to rapid improvements in Bjoergen's performance.

"But then her improvements stagnated after a few years," Solli said.

Bjoergen's next major improvement in her performance happened after she switched to a more even distribution of high-intensity training and to relatively large amounts of low-intensity training, Solli said.

"While Marit's high-intensity and medium-intensity training levels are similar to what has been previously reported in other world-class XC skiers, the volume of her low-intensity training is remarkably high," Solli said.

As an elite skier, Bjoergen was also able to train at altitude in preparation for races, something that is not an option for the average amateur athlete. And she spent roughly 60 % of all of her annual workout time in ski-specific training, either on snow or on roller skis.

A healthy body image

One aspect of Bjoergen's success, Solli thinks, is that she has been able to clearly balance her training with maintaining a healthy body weight. The 167 cm tall athlete has always kept her weight at around 65 kg.

It can be tempting for athletes from all disciplines to want to improve their performance by losing weight or keeping their weight extremely low, but that's not a prescription for long-term success, Solli says.

"Marit shows that you should be able to preform at a top level and still be healthy. Being a professional athlete is extremely demanding, and you can debate how healthy it is to continually be pushing your body to its limits, but she is an example that it's possible," Solli said.

Put 50 newborn worms in 50 separate containers, and they'll all start looking for food at roughly the same time. Like members of other species, microscopic C. elegans roundworms tend to act like other individuals their own age.

It turns out that the innate system that controls age-appropriate behavior in a developing worm is not entirely dependable, however. Despite sharing identical genes and growing up in similar environments, some individual worms will inevitably march to the beat of their own drum.

New research from Rockefeller University illuminates the biology that guides behavior across different stages of life, and also suggests how variations in specific neuromodulators in the developing nervous system may lead to occasional variations. The work, led by Cori Bargmann, is made possible by a newly engineered system that allows scientists to record behavioral information for individual worms over an entire lifecycle. It is published in Cell.

"There are patterns at every stage of life that are different from the patterns at other stages, and with the system we created we can see that really clearly in ways that are surprisingly complex and robust," says Bargmann, who is the Torsten I. Wiesel Professor and head of the Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior. "We can also observe something as complex as individuality and start to break down the biology behind it."

Chemical conformity

Our understanding of how genes govern behavior comes largely from experiments that involve altering a subject's normal state with external stimuli over a short period of time, such as giving a mouse some cheese as a reward for completing a maze. We know less about how genes affect behavior as animals go about their normal routines.

Shay Stern, a postdoctoral associate in Bargmann's laboratory, engineered a system to capture spontaneous, internally-generated behavior in worms over the span of their entire development, which totals about 50 hours. The scientists focused on foraging behavior--the worms' roaming movements in search for food--and found incredibly similar patterns of activity between individuals.

"Even though the worms were separated and not receiving external cues, they were actively searching for food at the same time point in development as other worms," says Stern. "And we saw very precise differences in foraging behavior at each stage of development."

By creating genetic mutations in some worms, the researchers were also able to identify specific neuromodulators, or chemical messengers in the brain, that normally keep the animals on schedule. A mutation that disrupted the chemical messenger dopamine, for example, affected the worms' roaming speed during late development. Other mutations affected behavioral patterns within each developmental stage, suggesting that different neuromodulators influence behavior over different timescales.

Born this way

While the majority of worms conformed to the same behavioral patterns, a number of individual worms stood out for their atypical foraging behaviors. Variability between individuals is typically attributed to genetic differences or exposure to different environments, but the researchers designed this study to account for these differences, using genetically identical worms in identical environments.

One explanation for these individual variations could be small differences in how the nervous system develops. There is a randomness factor in how some neurons connect with each other that isn't controlled by genetics, notes Bargmann.

But Bargmann and colleagues showed that neuromodulators can also contribute. The researchers found that removing the chemical messenger serotonin from a population of worms drastically reduced the number of worms that displayed unique roaming patterns, or individuality. Indeed, without serotonin, all of the worms exhibited the same foraging behavior at the same time--a finding that suggests how important individuality is to survival.

"From an evolutionary point of view, we can't have everyone going off the cliff all at once like lemmings--someone's got to be doing something different for a species to survive," says Bargmann.

NASA-NOAA's Suomi NPP satellite and the GPM core satellite passed over Tropical Cyclone Gita is it began weakening from vertical wind shear.

Warnings and watches are in effect for New Caledonia and Zealand is on alert for Tropical Cyclone Gita. In New Caledonia, the majority of the territory is on pre-alert with the exception of the Ile des Pins, which is on Alert #2. New Zealand is expected to be affected by Gita on February 19 and 20 and the meteorological service is tracking the storm.

The Global Precipitation Measurement mission or GPM core observatory satellite's Microwave Imager (GMI) instrument had a fairly good view of Tropical Cyclone Gita on February 16, 2018 at 0316 UTC (Feb. 15 at 10:16 a.m. EST). GPM's Dual Frequency Precipitation Radar (DPR) swath only covered the area west of GITA's main area of precipitation. The weakening tropical cyclone was passing the southeastern tip of New Caledonia. Although weakening, Gita still had winds estimated at over 90 knots (104 mph). Rainfall derived from GMI data showed that the heaviest precipitation, falling at rate of about 51 mm (2 inches) per hour, was shown west of Gita's eye. GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.

On Feb. 16 at 0206 UTC (Feb. 15 at 9:06 p.m. EST) the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA's Suomi NPP satellite showed the eye of Gita southeast of New Caledonia. Some high level clouds have filled in the eye, but it was still quite visible in the VIIRS image.

On Feb. 16 at 10 a.m. EST (1500 UTC) Tropical Cyclone Gita's maximum sustained winds were near 92 mph (80 knots/148 kph). Gita was centered near 23.8 degrees south latitude and 167.6 east longitude, about 135 nautical miles southeast of Noumea, New Caledonia. Gita was moving to the west-southwest at 11.5 mph (10 knots/18.5 kph).

At that time, the Joint Typhoon Warning Center (JTWC) noted that "animated enhanced infrared satellite imagery shows a weakening tropical cyclone with a decaying convective structure, and vertical wind shear is pushing the thunderstorms away from the center of circulation.

Strong vertical wind shear are now sapping tropical cyclone Gita's strength. The JTWC predicts that the tropical cyclone will continue to weaken as Gita moves southwestward and encounters cooler ocean waters. Gita is expected to change course and move toward the southeast in a few days. A recent JTWC forecast indicates that Gita will transition to an extra-tropical low and move to a location between New Zealand's North and South Islands on February 20, 2018.

The Meteorological Service of New Zealand noted "Tropical Cyclone Gita continues to track southwards on Sunday and is likely to encounter an upper trough in the northern Tasman Sea. The system is likely to undergo extra-tropical transition on Sunday before tracking to the southeast towards New Zealand on Monday under the influence of the upper trough."

For updated warnings and watches in New Zealand, visit: http://www.metservice.com/warnings/tropical-cyclone-activity.