Brain

In a remote village, an aid worker pricks a sickly toddler's fingertip, and like most of the other children's blood samples, this one turns a test strip yellow. That's how an experimental malnutrition test made with bacterial innards could work one day to expose widespread zinc deficiencies blamed for roughly half a million deaths annually.

These innards include plasmids, which are loops of DNA. They are not the same DNA strands behind reproduction and cell construction, but function instead like nano-organs with genetic programs that normally guide bacterial cell processes. In a study led by the Georgia Institute of Technology, researchers engineered their own plasmids to direct other parts extracted from bacteria to make the blood test work.

The new technology showed high potential as a basis for an inexpensive, easy malnutrition test for use in the field that could be expanded to include many vital nutrients and other health indicators.

The new, experimental test is freeze-dried to a powder that is kept at everyday temperatures, could be read in the field, and may be suitable for precise analysis with an applicable smartphone app. It could overcome the clinical and logistical travails of other tests, including refrigerated transport to the field or back to a lab, as well as lost time.

The test not only detects zinc but also quantifies its clinically relevant levels, which is necessary to detect malnourishment and is one of the new test's main innovations. Aid agencies could use a field version of the test to get immediate information to quickly influence policy decisions on nutritional interventions.

Hidden hunger

Two billion people worldwide suffer from micronutrient deficiencies, which claim millions of lives each year, according to the Centers for Disease Control and Prevention. Zinc deficiency alone was blamed for more than 450,000 deaths in 2009, according to a study in the European Journal of Clinical Nutrition.

But spotting malnutrition is tricky.

"In the developing world today, many people may get enough calories but miss out on a lot of nutrients. You can look at someone and tell if they're getting enough calories but not if they're getting sufficient amounts of developmentally important nutrients," said Mark Styczynski, who led the study and is an associate professor in Georgia Tech's School of Chemical and Biomolecular Engineering.

"The impact is greatest on pregnant mothers and children under the age of 5, which is when they have the highest mortality," he said.

The research team, which included collaborators from Northwestern University, published their study in the journal Science Advances on September 25, 2019. The research was funded by the National Institutes of Health, the National Science Foundation, the Air Force Research Laboratory, the Defense Advanced Research Projects Agency, the David and Lucille Packard Foundation, and the Camille Dreyfus Teacher-Scholar Program.

Small is huge

Engineering with bacterial innards is at least 25 years old, with research accelerating in the past decade. But this new test flags small molecules, like zinc or iodine, another big innovation.

The quantification of zinc ions in this particular study was the proof of concept for plans to measure many small molecules relevant to in-field tests. The researchers could quickly expand the test to assess levels of the six vital small-molecule nutrients, micronutrients, that are highly relevant to nutritional fieldwork.

"We may be able to reasonably quickly make new tests for iron, B12, folate, iodine, and vitamin A," Styczynski said. "We could also quantify bigger molecules like DNA and proteins to help figure out how bad a viral outbreak is."

"Detecting the presence or absence of something like Ebola or pregnancy is important. But being able to say how much of something you have, like a nutrient or a virus, without having to haul equipment through the field to do it has been lacking. The ability to do it could open a lot of doors in diagnostics and treatment," Styczynski said.

Disemboweling bacteria

The ease of use of the experimental zinc test stands in stark contrast to the labors required to engineer it. The researchers started off using live bacteria that changed colors in reaction to zinc, but that approach hit snags.

"The test took too long, and the volume of blood and bacteria we would need was not clear," Styczynski said. "So, we went cell-free. You take the bacteria and remove the outside and the genome -- the main DNA -- and you're left with this rich mixture of heavily reactive parts, to which you can add your own genetic program on the plasmids."

Cell-free approaches allow bacterial innards to be dosed like compounds in a chemical reaction, making the test predictable, reliable, and suitable for standardization. The researchers built two plasmids to drive the test's processes.

"One has the genes taken from E. coli for an enzyme that breaks down a big sugar into smaller sugars. The other one controls how much of a regulator gene is being turned on in response to levels of zinc," Styczynski said.

Turning purple

The test uses a signal molecule that is partly a big sugar and starts out yellow, but once the plasmid makes an enzyme that cleaves the sugar, the molecule turns purple. Zinc levels regulate how much enzyme is made -- more zinc means more enzyme and more purple. If the test remains yellow, zinc is perilously low.

When tested in serum, i.e. blood, its rich biology clutters the reaction, and in the real world, that clutter differs from person to person and would skew color schemes from patient to patient.

The researchers solved this with a chemical trick to make a calibration system that flows with that skew. For the actual test, the zinc regulated how the plasmids alter the color, but the study's first author, Monica McNerney, flipped things for the calibrator.

To make its reference points, she maxed out zinc levels and varied the levels of plasmids point by point, resulting in a scale of colors.

The test and the plasmid-varied calibration points both received the serum to be tested, and the clutter shifted the test and the calibration points in an identical manner. The changed color of the test could be accurately compared to the colors of the calibration points to ascertain zinc levels.

The colors are in the visible range, not fluorescent, so they require no device to read. The speed of color change could reveal more detail about nutrient levels, perhaps via an analysis of smartphone video taken of the test.

What species is better at fighting an infection, a mouse or an elephant? Body size is one of the most noticeable differences among species, but relationships between immune defenses and body size have largely been unstudied.

Hamilton College Assistant Professor of Biology Cynthia J. Downs led a study with co-authors Ned Dochtermann (North Dakota State University), Kirk Klasing (University of California, Davis), Ray Ball (Eckerd College), and Lynn (Marty) Martin (University of South Florida) that investigated whether body mass was related to concentrations of two important immune cell types in the blood among hundreds of species of mammals ranging from tiny Jamaican fruit bats (~40 g) to giant killer whales (~5,600 kg). Their results appear in The Effects of Body Mass on Immune Cell Concentrations of Mammals, recently published online by The American Naturalist. The study was funded by grants from the National Science Foundation.

The researchers found that concentrations of lymphocytes, one type of white blood cell, didn't change in any special way with body size. That is, a mouse and an elephant have the same number of lymphocytes per ml of blood.

In contrast, big mammals had far, far more neutrophils in circulation than small species. Neutrophils are involved in early immune responses to many different kinds of invaders including bacteria and even bigger parasites such as worms.

The researchers speculate that larger mammals might need so many more circulating neutrophils to overcome the inherent advantage that infectious agents have over the animals they infect. This advantage arises because small things replicate their cells much faster than big things; to offset this benefit of being small, big things maintain a large pool of nasty cells to attack invaders.

This work shows that for some types of immune defenses, large and small mammals are fundamentally different. Downs and co-author Martin observed that this insight may help in developing better ways to link results from lab mice to improvements of human health as well as in enabling scientists to make predictions about the immune systems of species never before studied. The co-authors speculate that these data could also even help wildlife managers predict how good a species could be as a host for a newly emerging disease.

Highlights

In an analysis of published studies, a healthy dietary pattern was associated with a 30% lower incidence of chronic kidney disease.

A healthy dietary pattern was also linked with a 23% lower incidence of albuminuria, an early indicator of kidney damage.

Washington, DC (September 24, 2019) -- Maintaining a healthy diet may help prevent kidney disease, according to an analysis of published studies. The findings appear in an upcoming issue of CJASN.

Making dietary changes can help slow the progression of chronic kidney disease (CKD), but it's not clear whether a healthy diet is protective against the development of the disease. To investigate, Jaimon Kelly, PhD, Katrina Bach (Bond University, Australia), and their colleagues analyzed all relevant studies published through February 2019.

The analysis included 18 studies with a total of 630,108 adults who were followed for an average of 10.4 years. Healthy dietary patterns typically encouraged higher intakes of vegetables, fruit, legumes, nuts, whole grains, fish, and low-fat dairy, and lower intakes of red and processed meats, sodium, and sugar-sweetened beverages.

A healthy dietary pattern was associated with a 30% lower incidence of CKD. It was also linked with a 23% lower incidence of albuminuria, an early indicator of kidney damage.

"These results add to the accumulating evidence base supporting the potential benefit of adhering to a healthy dietary pattern--such as the Mediterranean, DASH diet, or National Dietary Guidelines--and the primary prevention of chronic conditions, including type 2 diabetes, cardiovascular disease, cognitive decline, cancer, and all-cause mortality," said Dr. Kelly. "These results may assist in developing public health prevention programs for CKD, which may assist in reducing the burden of the disease." Dr. Kelly noted that dietary approaches to kidney health that target individual (or multiple) nutrients can be difficult, but focusing on whole foods rather than nutrients can make it easier for clinicians to educate patients and easier for patients to carry out.

"Randomized clinical trials with sufficient follow-up time to ascertain meaningful kidney outcomes are necessary to determine whether a change in dietary patterns is causally related to favorable kidney health outcomes," wrote the authors of an accompanying editorial. "Meanwhile, there may be sufficient observational evidence for clinicians to emphasize the importance of healthy dietary patterns to individuals who are healthy or who are at risk of developing CKD."

An accompanying Patient Voice editorial notes the importance of including children in future studies.

Astrophysicists Jon Hakkila of the College of Charleston and Robert Nemiroff of the Michigan Technological University have published research indicating that blasts that create gamma-ray bursts may actually exceed the speed of light in surrounding gas clouds, but do so without violating Einstein's theory of relativity. Hakkila and Nemiroff propose that such superluminal jets could create the time-reversibility seen in gamma-ray burst light curves. These proposed jets, however, do not violate the Einstein's relativity because they only move faster than light does through the jet medium, not faster than light through vacuum.

Hakkila says that a good way to visualize this superluminal motion is to imagine someone on one side of a pond skipping a stone across the water in your direction. The frequently-hopping stone moves through the air between hops faster than the waves it generates move through water. Hakkila says you would see waves created by each skip of the approaching stone in reverse order, with waves from the most recent skip arriving first and those from the initial skip arriving last. This superluminal blast explanation retains many characteristics of accepted gamma-ray burst jet models, Hakkila says. Nemiroff adds, however, that their proposed scenario involves Cherenkov radiation, a type of light created by superluminal motion that was not previously thought to be important in generating the light curves of gamma-ray bursts.

"Standard gamma-ray burst models have neglected time-reversible light curve properties," Hakkila says. "Superluminal jet motion accounts for these properties while retaining a great many standard model features."

Molluscan shells consist of a variety of complex mineral-organic composite ultrastructures. Surprisingly, in some cases, shells from distantly related species contain similar morphological motifs on many different length scales, from the nano- to the micro-scale. During the last few decades, significant progress has been made in understanding the key biochemical mechanisms responsible for biogenic mineral formation. However, little is known on how the organisms control the form of the individual mineral building blocks comprising the different shell architectures and consequently, determine the morphology of these species-specific mineral-organic assemblies.

The Zlotnikov research group in collaboration with scientists from the Wigner Research Centre for Physics in Budapest, Hungary now developed a comprehensive experimental and theoretical framework to analytically describe the process of ultrastructural morphogenesis of molluscan shells. Mainly, they demonstrated that the formation of these highly biomineralized tissues is guided by the organisms by regulating the chemical and physical boundary conditions that control the growth kinetics of the mineral phase.

By showing a direct link between physics of materials and the process of biomineralized tissue morphogenesis, the team sheds a new light on the evolutionary aspect of the fabrication of biological materials.

When exposed to stress and strain, materials can display a wide range of different properties. By using sound waves, scientists have begun to explore fundamental stress behaviors in a crystalline material that could form the basis for quantum information technologies. These technologies involve materials that can encode information in a number of states simultaneously, allowing for more efficient computation.

In a new discovery by researchers at the U.S. Department of Energy’s Argonne National Laboratory and the Pritzker School of Molecular Engineering (PME) at the University of Chicago, scientists used X-rays to observe spatial changes in a silicon carbide crystal when using sound waves to strain buried defects inside it. The work follows on an earlier recent study in which the researchers observed changes in the spin state of the defect’s electrons when the material was similarly strained.

“We’re directly imaging sound's footprint going through this crystal.” — Argonne materials scientist and Pritzker School of Molecular Engineering staff scientist Joseph Heremans

Because these defects are well isolated within the crystal, they can act as a single molecular state and as carriers of quantum information. When the electrons trapped near the defects change between spin states, they emit energy in the form of photons. Depending on which state the electrons are in, they emit either more or fewer photons in a technique known as spin-dependent readout.

In the experiment, the researchers sought to assess the relationship between the sound energy used to produce the strain on the defects in the crystal lattice and the spin transitions indicated by the emitted photons. While the defects in the crystal naturally fluoresce, the additional strain causes the ground spin of the electron to change state, resulting in a coherent manipulation of the spin state that can be measured optically.

“We wanted to see the coupling between the sound strain and the light response, but to see exactly what the coupling between them is, you need to know both how much strain you’re applying, and how much more optical response you’re getting out,” said Argonne nanoscientist Martin Holt, the lead author of the study.

The electrodes used to generate the sound waves are roughly five microns in width, far larger than the defects themselves, which consist of two missing atoms known as a divacancy complex. The sound wave strains the defects by alternately pushing and pulling on them, causing the electrons to change their spins.

To characterize the lattice and defects, Argonne researchers used the Hard X-ray Nanoprobe beamline operated jointly at the laboratory’s Center for Nanoscale Materials and Advanced Photon Source (APS), both DOE Office of Science User Facilities. Through a newly developed technique called stroboscopic Bragg diffraction microscopy, Holt and his colleagues were able to image the lattice around the defects at many different points throughout the strain cycle.

“We’re interested in how to manipulate the original spin state with acoustic waves, and how you can spatially map out the mechanics of the strain with X-rays,” said Argonne materials scientist and PME staff scientist Joseph Heremans, another author of the study.

“The X-rays measure exactly the lattice distortion,” Holt added.

Stroboscopic Bragg diffraction involves synchronizing the frequency of the acoustic wave to the frequency of the electron pulses in the APS’s storage ring. In this way, the researchers were essentially able to “freeze the wave in time,” according to Holt. This allowed them to create a series of images of the strain experienced by the lattice at each point on the wave.

“It’s like if you had ripples in a pond, and you could shine a light on one spot of the pond,” Holt said. “You’d see a movement of peak to trough, and trough to peak.”

“We’re directly imaging sound’s footprint going through this crystal,” Heremans added. “The sound waves cause the lattice to curve, and we can measure exactly how much the lattice curves by going through a specific point of the lattice at a specific point in time.”

The use of stroboscopic Bragg diffraction allows scientists to determine the direct correlation between the dynamic strain and the quantum behavior of the defect, Holt said. In silicon carbide, this relationship is fairly well understood, but in other materials the technique could reveal surprising relationships between strain and other properties.

“This technique opens a way for us to figure out the behaviors in a lot of systems in which we don’t have a good analytical prediction of what the relationship should be,” Holt said.

“This study combines expertise from a leading academic institution with state-of-the-art instrumentation of a national laboratory to develop a novel technique for probing matter at the atomic scale, revealing the ability of sound waves to control semiconductor quantum technologies,” added Argonne senior scientist and PME Liew Family Professor of Molecular Engineering David Awschalom, a collaborator on the research.

Scientists from the RIKEN Center for Integrative Medical Science and Istituto FIRC di Oncologia Molecolare (IFOM), along with collaborators from Kyoto University, the Karolinska Institut, and DNAFORM, have developed a new technique, NET-CAGE, to elucidate the structure of a type of non-coding portion of the genome called enhancers, which function to activate specific genes. These parts of the genome, which were once thought to be unimportant and called "junk DNA," are now known to be associated with a variety of diseases, and understanding their function has become an important goal with genomic research.

It is now known that there are two types of genomic regions, known as promoters and enhancers, that work to coordinate the activation of protein-coding genes, essentially by switching them on. While promoters are located right next to the genes they activate, enhancers are located faraway, but somehow act upon the genes as well. A variety of techniques have been developed to try to map enhancers, but they all had limitations, either lacking sensitivity of identification, the ability to pinpoint the location of the regions or being ill-suited for use in frozen cells, for example.

To overcome these limitations, the researchers developed a method called NET-CAGE, which is an extension of the CAGE technology developed at RIKEN to identify non-coding regions of the genome with high sensitivity, and used it to examine five commonly used types of cancer cell lines. They were happy to find that the method can be used on cryopreserved cells.

Using the new method, the researchers made a series of interesting discoveries regarding enhancers. First, they identified as many as 20,000 new enhancers in humans. They found that while promoters are activated in a variety of cell types, enhancers tend to function in just one cell type, thus showing an important difference between the two types of region. They also uncovered an intriguing link between the two types of regions, showing that they are linked topologically according to their cell type specificities. And in addition, they pinpointed the exact location of active enhancers at high nucleotide resolution within cluster regions known as "super enhancers."

According to Yasuhiro Murakawa of RIKEN IMS, who led the team along with Hideya Kawaji, "We have found that enhancers play an essential role in generating a cell type-specific transcriptome. The new method that was developed in this study can be used to study many aspects of biology. In the long term, the method can be implemented into the next-generation genomic medicine."

"Using this technology," he continues, "we are making a comprehensive map of enhancer activation in the human body. By integrating the knowledge with data on mutations associated with disease and cancer genomics data, we hope to increase of understanding of the mechanisms of diseases."

The group is currently commercializing a NET-CAGE kit in collaboration with K.K. DNAFORM, a genomics technology company that was established in 1998 as a RIKEN venture.

New Rochelle, NY, September 23, 2019-Damage to the meniscus is common, but there remains an unmet need for improved restorative therapies that can overcome poor healing in the avascular regions. Now, researchers have reported a new method that may help by growing meniscal cells on 3D electrospun nanofiber scaffolds. Their work is published in Tissue Engineering, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers. Click here to read the article for free on the Tissue Engineering website through October 23, 2019.

Darryl D. D'Lima, MD, PhD, Shiley Center for Orthopaedic Research at Scripps Clinic, La Jolla, CA, with colleagues from Scripps Clinic and Scripps Research Institute, present their work in an article titled "Core-Shell Nanofibrous Scaffolds for Repair of Meniscus Tears". The authors created a core-shell scaffold material by the co-axial electrospinning of a polylactic acid core with a collagen shell, seeded it with meniscal cells, and monitored tissue development based on gene expression and histology. These constructs were used to repair tears in meniscal explants and showed good integration.

"Meniscal injuries in the avascular region can be notoriously difficult to treat," says Tissue Engineering Co-Editor-in-Chief Antonios G. Mikos, PhD, Louis Calder Professor at Rice University, Houston, TX. "The ex vivo tissue repair results from this article demonstrate the therapeutic promise of the co-axial electrospinning strategy, potentially altering the treatment paradigm for such injuries."

Glioblastoma is the most frequent and aggressive brain cancer due to its ability to escape the immune system. However, the way in which this tumor manages to induce this immune tolerance was not known in detail. A research published in PNAS carried out at the Instituto de Neurociencias UMH-CSIC, in Alicante (Spain), and the IMIB-Arrixaca in Murcia (Spain), has find out in detail how this tumor invade healthy tissue with hardly any resistance, a finding that could become glioblastoma´s Achilles heel.

The team led by Dr. Salvador Martínez, director of the UMH-CSIC Institute of Neurosciences in Alicante (Spain), and Dr. Rut Valdor, of IMIB-Arrixaca in Murcia (Spain), has shown how glioblastoma hijacks the contractile cells that surround the blood vessels of the brain and are also part of the barrier that protects it. The objective is to deactivate the antitumoral function of that these cells, called pericytes, and force them to work on the expansion of the tumor.

This change in the function of the pericytes, which are no longer defending cells to become "enemies", is achieved by glioblastoma by altering one of the cellular "cleaning services": chaperone mediated autophagy. Through autophagy the cell breaks down and destroys damaged or abnormal proteins. And chaperones are proteins that actively work on this task. The alteration by the glioblastoma of this cleaning service changes the proinflammatory defense function of the pericytes by another immunosuppressive, which favors the survival of the tumor.

Inactivating the tumor

Researchers have been able to verify in a mouse model that blocking this anomalous autophagy hinders the development of the tumor, causing defective adhesion of glioblastoma to the pericyte and, with it, the death of cancer cells, so it becomes a promising therapeutic goal.

"This work reveals a previously unknown capacity of glioblastoma to modulate chaperone mediated autophagy (AMC) in pericytes, and thus promote tumor progression. Our results point to the AMC as a promising therapeutic goal to treat this aggressive brain cancer so far without cure", says Dr. Martínez.

Previous this group showed that the influence of glioblastoma on the pericyte prevents destructive T lymphocytes from attacking the tumor. "That is why the brain does not detect glioblastoma and cannot react against it," explains Salvador Martínez, director of the Experimental Neurobiology group at the Instituto of Neurociencias UMH-CSIC in Alicante.

This new finding narrows the fence against this aggressive brain tumor and is in line with the current hypothesis about the role of autophagy in suppressing the early stages of tumor development and how alterations in this process contribute to its progression.

Glioblastoma multiforme is a highly invasive cancer that is characterized by changes in cerebral blood vessels and the gradual invasion of surrounding tissues. It is the most frequent brain tumor with the worst prognosis. Despite decades of intense research, its complex biology is still not fully understood and existing treatments have not achieved a significant increase in survival.

FORT LAUDERDALE/DAVIE, Fla. - With the recent celebration of the 50th anniversary of the Apollo program's first landing of humans on the moon, the eyes and hopes of the world turn skyward again.

The romantic notions of exploring and even colonizing space have been re-kindled, with the above and more recent movies such as The Martian and the fictional planting of potatoes. The ambitious spirit is further spurred by private space enterprises such as Elon Musk's SpaceX, Jeff Bezos' Blue Origins, and the idea that we may need a "Planet B", as our own planet's natural habitats become more stressed and the human population exponentially increases.

Jose Lopez, Ph.D., a professor at Nova Southeastern University's (NSU) Halmos College of Natural Sciences and Oceanography, has now joined the movement with a peer reviewed scientific opinion article calling for a rational and systematic approach to future space colonization of Mars or other planets. He and colleagues Raquel Peixoto and Alexandre Rosado from Federal University of Rio de Janeiro have just published the scientific opinion paper entitled "Space Colonization Beyond Earth with Microbes First" in the journal FEMS Microbiology Ecology -
https://academic.oup.com/femsec/article/95/10/fiz127/5553461

Lopez is a research scientist and claims microbes would be a better immediate investment to successfully colonize the red planet.

"Life as we know it cannot exist without beneficial microorganisms," he said. "They are here on our planet and help define symbiotic associations - the living together of multiple organisms to create a greater whole. To survive on a barren (and as far as all voyages to date tell us) sterile planets, we will have to take beneficial microbes with us. This will take time to prepare, discern and we are not advocating a rush to inoculate, but only after rigorous, systematic research on earth."

Lopez and colleagues now assert that this rigorous microbial research agenda needs to be implemented for any future successful colonization of Mars. Moreover, microbes should probably supersede current ambitions to send people to Mars or other solar system locales, as they can condition or terraform places we may want to eventually colonize.

In the long run, the effort will save humanity money, can be life-sustaining and boost microbiological understanding

However, to determine the most useful microbes for space requires a lot more research here on earth.
In the publication, the researchers encapsulate this idea into a potential research regime called PIP or "Proactive Inoculation Plan", which encompasses the screening of potential hardy microbial candidates, toxic or lethal genes, and describing mechanisms for the most productive symbiosis.

"Life on earth started with relatively simple microorganisms which have the capacity to adapt and evolve to extreme conditions, which defined earth's habitats in the ancient past," Lopez said. "Cyanobacteria for example provided most of the oxygen we now breath more than two billion years ago. To the find the best microbial candidates, we will have to confer with many microbiologists and carry out research here on our home planet to find the optimal microbial species."

EVANSTON, Ill. -- Researchers have developed a tiny nanolaser that can function inside of living tissues without harming them.

Just 50 to 150 nanometers thick, the laser is about 1/1,000th the thickness of a single human hair. At this size, the laser can fit and function inside living tissues, with the potential to sense disease biomarkers or perhaps treat deep-brain neurological disorders, such as epilepsy.

Developed by researchers at Northwestern and Columbia Universities, the nanolaser shows specific promise for imaging in living tissues. Not only is it made mostly of glass, which is intrinsically biocompatible, the laser can also be excited with longer wavelengths of light and emit at shorter wavelengths.

"Longer wavelengths of light are needed for bioimaging because they can penetrate farther into tissues than visible wavelength photons," said Northwestern's Teri Odom, who co-led the research. "But shorter wavelengths of light are often desirable at those same deep areas. We have designed an optically clean system that can effectively deliver visible laser light at penetration depths accessible to longer wavelengths."

The nanolaser also can operate in extremely confined spaces, including quantum circuits and microprocessors for ultra-fast and low-power electronics.

The paper was published today (Sept. 23) in the journal Nature Materials. Odom co-led the work with P. James Schuck at Columbia University's School of Engineering.

While many applications require increasingly small lasers, researchers continually run into the same roadblock: Nanolasers tend to be much less efficient than their macroscopic counterparts. And these lasers typically need shorter wavelengths, such as ultraviolet light, to power them.

"This is bad because the unconventional environments in which people want to use small lasers are highly susceptible to damage from UV light and the excess heat generated by inefficient operation," said Schuck, an associate professor of mechanical engineering.

Odom, Schuck and their teams were able to achieve a nanolaser platform that solves these issues by using photon upconversion. In upconversion, low-energy photons are absorbed and converted into one photon with higher energy. In this project, the team started with low-energy, "bio-friendly" infrared photons and upconverted them to visible laser beams. The resulting laser can function under low powers and is vertically much smaller than the wavelength of light.

"Our nanolaser is transparent but can generate visible photons when optically pumped with light our eyes cannot see," said Odom, the Charles E. and Emma H. Morrison Professor of Chemistry in Northwestern's Weinberg College of Arts and Sciences. "The continuous wave, low-power characteristics will open numerous new applications, especially in biological imaging."

"Excitingly, our tiny lasers operate at powers that are orders of magnitude smaller than observed in any existing lasers," Schuck said.

A snapshot of health conditions revealing the disparities across 38 neighborhood areas in Harris County has been published in the 2018 Health of Houston Survey by The University of Texas Health Science Center at Houston (UTHealth) School of Public Health.

The report, available online to the public, details patterns of illness and health practices, insurance coverage, access to care, mental health, prenatal care, diet and exercise, and neighborhood problems of greatest concern to residents. It also pinpoints where the highest percentage of residents live in the poorest health, have the greatest food insecurity, report the lowest rates of health insurance coverage, or suffer from serious chronic health conditions.

The survey gathered information about adults and children from telephone interviews in English and Spanish with residents in 5,694 Harris County households.

"This kind of data is critical to identifying unmet health needs throughout the county and being able to pinpoint areas and groups of residents where the need is greatest. Relying on it, organizations and authorities can target services more effectively and ensure that interventions are directed where they will help the most," said Stephen H. Linder, PhD, director of the Institute for Health Policy at UTHealth School of Public Health and principal investigator of the survey.

The 2018 edition, which builds on the landmark 2010 survey, is one of the largest and most comprehensive of its kind nationally, and is unique in offering its data to the public on two web-based platforms, one using maps and the other, simple tabulations of survey responses. The emphasis is placed on both access and ease of use, since the intent is to reach different users, from researchers to health systems, and from nonprofits to city and county officials.

Some key findings from the 2018 Survey:

On a range from poor to excellent health, 20% of Harris County residents rated themselves in fair or poor health with the highest percentages of those living in Aldine and Settegast, followed by Edgebrook, Gulfton, and South Acres Homes.

Along with Settegast, Aldine, and Gulfton, the areas of North Acres Home, Champions, Galena Park, and South Alief reported the highest percentage of adults facing economic hardship. Black residents were more likely than any other group to experience economic hardship and face food insecurity regularly.

Obesity, high blood pressure, and diabetes were the most common chronic conditions affecting county residents. Diabetes rates in the county varied from less than 9% in the far northwest to 17%-26% in the northeast and east. Areas with the highest rates of diabetes included Humble, Galena Park, East End, Settegast, and Gulfton. Some areas saw large increases. In the 2010 survey, for example, the rate of diabetes in Gulfton was 15% while the 2018 rate rose to 21.3%.

With the Affordable Care Act implemented fully in 2014, fewer Harris County residents were uninsured in the 2018 survey, 27%, compared to 31% in 2010. Respondents reported that 11% of children were uninsured versus 13% in 2010. Of adults under age 65, 37% were without health insurance at some point in the last year. Hispanics were disproportionately affected, with 56% going without health insurance at some point. Areas where residents were most likely to be uninsured included Pasadena, Bellaire, Galena Park, Gulfton, and Aldine. Areas with the greatest number of uninsured children were Aldine, Settegast, Pasadena, Edgebrook, and South Houston.

Nearly 16% of all residents reported that they could not afford or delayed filling a prescription for themselves or a family member in the past year; 18% could not see or delayed seeing a specialist; 10% did not seek or delayed seeking mental health care; and 24% delayed or could not get dental care services.

Gulfton and Aldine areas had the highest percentage of uninsured and faced three or more barriers to access. Areas with both high percentages of uninsured children and access barriers included La Porte, West Clear Lake, East End, and Galena Park.

Obesity rates of teens age 14-17 rose from 11% in 2010 to 16% in 2018. Areas of children with unhealthy weights (overweight and obese) ages 12-17 included Gulfton, Bellaire and South Alief, North FM 1960, Champions, Katy, and Tomball with rates ranging from 43% to 46%. The average for the county was 32.8%.

The rate of serious psychological distress was 7%, the same as in 2010, still, it had decreased to 6% just before Hurricane Harvey in 2017, rising just after and remaining at 8% six to nine months after Harvey. Frequent mental distress, defined as 14 or more days of poor mental health over the last 30 days, was reported by 17% six to nine months after Harvey, which is nearly 5 percentage points higher than the average before the storm (13%). Rates of distress rose with severity of storm damage experienced by the residents.

Of the 17% of county residents who reported they needed mental health care in the last year, only 44% in that group received it. Areas with the highest need for mental care services were South Acres Home, Edgebrook, South Alief, Greater Uptown, Spring, and Champions. The South Alief area had one of the highest rates of residents needing mental health services, 23%, and one of the lower rates of mental health care visits, 6%.

Overall there was a drop in the percentage of county residents who reported neighborhood and environmental concerns but stray animals continued to be the top concern at 34%, particularly in Aldine, Edgebrook, Settegast, South Acres Home, and Galena Park. Other concerns were crime, 22%; lack of fresh fruits and vegetables, 21%; no sidewalks, 22%; and no park or playground near where they lived, 21%.

The 2018 survey was funded by Houston Endowment, Episcopal Health Foundation, Texas Children's Hospital, Memorial Hermann Health System, Community Health Choice/Harris Health System, UTHealth-President's Excellence Fund, UTHealth School of Public Health-Office of the Dean, and TMC-Health Policy Institute.

The full report and data from 2010 and 2018 can be found at http://www.healthofhouston.org.

Phoenix, Arizona, USA: From the Great Pacific garbage patch to inland rivers, plastics are among the most widespread contaminants on Earth. Microplastics -- particles of plastic smaller than five millimeters -- are especially pervasive. As they build up in Earth's waters, microplastics are also becoming a permanent part of the planet's sedimentary layers.

Now, using the Great Lakes as a laboratory, sedimentary petrologist Patricia Corcoran and her students at the University of Western Ontario are studying the behavior of microplastics as a geologic phenomenon.

What are the main sources of microplastics to Great Lakes sediment? What factors influence their distribution, and where do they concentrate? To explore these questions, and shed light on implications such as which animals may be at risk from microplastics, Corcoran's team has analyzed offshore and nearshore sediment samples from Lakes Huron, Ontario, Erie, and St. Clair, and their tributaries. Abundances were as high as 4270 microplastics particles per kilogram of dry weight sediment in lake sediment, and up to 2444 microplastic particles per kilogram in river sediment.

The team found that the more organic debris in the sample, the more microplastics. Benthic microplastics -- those incorporated into lake bottom sediments -- were also more abundant near high population areas, which are also associated with plastics industry locations.

Surprisingly, not all plastic fibers found in benthic samples were plastic after all. "When we chemically analyzed fibers only 33% were plastic. The others materials like dyed cotton or cellulose," Corcoran says. "So we can't assume that every fiber we see under the microscope is plastic."

Corcoran's team also sampled pellets (microplastics about the size of a lentil) from 66 beaches across all five Great Lakes. They found a total of 12, 974 pellets over 660 square meters of beach, about equivalent to an eighth the area of an American football field.

Except for the two beaches containing the most pellets, they found little relationship between population density or industry and number of pellets, says Corcoran. Instead, pellets were most concentrated near tributaries. "In other words," she says, "rivers and creeks are the main pathways used by pellets to reach the lakes."

Burial of microplastics in lake and river sediment is just one way Corcoran has explored how plastics are becoming part of Earth's future rock record. She's also investigated anthropogenic stones on a Hawaiian beach, which she and colleagues called "plastiglomerate."

The Great Lakes study will be presented by Sara Belontz of the University of Western Ontario, on Tuesday, 24 Sept., at 2:30 p.m., in Room 224A, North Building of the Phoenix Convention Center.
Paper 227-5: Anthropogenic Grains: Microplastics in Benthic Compartments of the Great Lakes Watershed
https://gsa.confex.com/gsa/2019AM/webprogram/Paper333149.html

Phoenix, Arizona, USA: Over the past 30 years, wildfires have gotten bigger, stronger, and occurred more often. As climates continue to warm, this trend will likely continue, causing disruption to landscapes and water systems alike.

Wildfires are destructive to ecosystems, but they can also set the stage for future issues. "After a wildfire, particularly a high-severity wildfire, you have significant impacts to the soil that affects the infiltration of water," says Brendan Murphy, a research associate at Utah State University.

The inability of water soaking into the ground can trigger flooding and erosion, says Murphy, eventually leading to something called a runoff-generated debris flows. As the water flows along the land surface, it can pick up and carry sediment and rocks. "If you [pick up] enough," he says, "You can get these big debris flows that can carry really large, course sediment downstream."

Murphy says in the western U.S. these debris flows generally happen in smaller basins. "Some of that sediment will go into the river; some of it may actually stay stored in the valley for decades, if not thousands of years," says Murphy.

"What we're trying to do is start thinking about what happens to that sediment after the wildfire," he says. Specifically, the researchers want to know how much sediment will be carried downstream, eventually making its way to a reservoir.

In the western U.S., reservoirs provide long-term storage of water for tens of millions of people. The researchers used modeling to understand the locations and severity post-wildfire erosion could pose to downstream reservoirs.

Murphy and his colleagues are investigating what effects wildfires might have on downstream reservoirs. Murphy will give an invited talk about their research at the GSA Annual Meeting in Phoenix on Sunday morning.

In previous work, scientists have developed models for estimating the risk of wildfires based on what sort of fuels were available, or models of potential debris flow areas after a wildfire. But Murphy says these models are stand-alone tools--understanding how the fires, debris flows, and sediment transfer are linked is especially important when estimating risks.

"What we're trying to do is create new linked models where we can take the predictions of post-wildfire erosion, network-scale sediment routing models, and actually predict how much of that sediment can make it downstream," he says. Murphy adds that the team is particularly interested in how much sediment might move downstream into a reservoir, and when that might occur.

They are initially testing their new modeling on six reservoirs around Salt Lake City, Utah, but have plans to expand across the entire state. Murphy says the team is hoping their new modeling will help bring researchers together in predicting the risks from post-wildfire sediment at a landscape scale. The team has been meeting with state and federal forest agencies as well as landowners and water managers to discuss risks and mitigation.

"Fire is not something we can avoid," says Murphy, adding that people need to become more accustomed to seeing fire on the landscape and dealing with the outcomes. Murphy says, "If we want to do a better job of managing our water resources moving forward, we need to do a better job of managing fire."

In the body's cells, some proteins are of vital importance as to which genes are active or turned off. Now, researchers from the University of Copenhagen and the Memorial Sloan Kettering Cancer Center have discovered which proteins are necessary in order to maintain the proper genetic regulation.

All of the more than 200 different cell types in our body contain the same DNA. Which of those genes that are expressed determine each cell type. Therefore, it is essential that the activity of the genes is controlled with great precision.

Thus, a stem cell may develop into anything from a skin to a bone cell, depending on which parts of the genome that are expressed.

The researchers in Professor Kristian Helin's research group have for several years worked to understand the mechanisms that control whether a gene is active or inactive. This research is crucial to the understanding of how cells become specialised and maintain their identity, the normal embryonic development, and how various diseases may develop.

In a new study, researchers working at the Biotech Research & Innovation Center (BRIC) and the Novo Nordisk Foundation Center for Stem Cell Biology (DanStem) at the University of Copenhagen as well as the Memorial Sloan Kettering Cancer Center in New York have achieved crucial new results.

The results were recently published in the scientific journal Molecular Cell and provide insight into the ways in which epigenetic mechanisms control the activity of genes.

'In addition, the results may have an impact on the future treatment of certain cancers related to the studied protein complex, including lymphoma, leukaemia and a special type of brain cancer that is often seen in children', says Kristian Helin, Professor at BRIC and Director of Research at the Memorial Sloan Kettering Cancer Center.

Turning On and Off

One of the key protein complexes that regulates whether genes are turned on or off is called PRC2. To ensure that the complex binds to the right places in the genome, a number of other proteins are associated to PRC2.

In the recently published article, the research group has studied the importance of six different proteins associated to PRC2, and the group has shown that all six proteins help direct PRC2 to the right places in the genome.

In 15 different combinations, the researchers removed the associated proteins from embryonic stem cells one by one. In this way, the researchers were able to study the contribution of each protein to the activity and binding of the PRC2 complex to specific areas. It was found that the ability to find the way to the right places in the genome remained intact until all six associated proteins were removed from the stem cells.

That finding surprised the researchers, says the study's lead author, Postdoc Jonas Højfeldt:

'We assumed that each of the associated proteins was responsible for its own area to where the PRC2 complex should be guided. Instead, we saw that they all contributed to the places where the complex binds. As long as just one of the associated proteins were left, the ability remained intact', he says.