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Cell component breakdown suggests possible treatment for multiple neural disorders  external link

UW-Madison research published today (Feb. 11, 2019) reveals how one mutation causes fragile X, the most common inherited intellectual disability.

“Fragile X syndrome has been studied as a model of intellectual disability because in theory it’s comparatively simple,” says senior author Xinyu Zhao, a professor of neuroscience in the Waisman Center at the University of Wisconsin–Madison.

Photo: Microscopic image of a neuron.

Microscope images from the lab of Xinyu Zhao compare neurons with normal or mutated fragile X gene. With the mutation, mitochondria were shorter and failed to join together. A loss of fusion impairs the neuron’s ability to communicate and plays a role in causing fragile X symptoms. Scale bar shows 10 microns. Adapted from Zhao lab, Waisman Center, University of Wisconsin–Madison

Fragile X patients have difficulty in learning and language, as well as temper tantrums, hyperactivity and extreme sensitivity to light and sound.  The fragile X gene is located on the X chromosome and its mutation affects about 1 in 4,000 boys and 1 in 7,000 girls.

Nearly half of fragile X patients are also diagnosed with autism.

Zhao’s new study, in the journal Nature Neuroscience, shows that when mutated, the fragile X gene fails to produce its unique protein. As a result, subcellular units called mitochondria inside developing neurons are malformed, so the neuron is unable to create the necessary network of branches and contacts it needs to communicate.

These mechanisms link the fragile X mutation to the profound intellectual deficits in fragile X syndrome, Zhao says.

By blocking the proper formation and function of mitochondria, the fragile X mutation may also play a role in several other conditions. About 2 to 3 percent of people with autism have fragile X syndrome. “Autism is linked to more than 1,000 genes,” she says. “Because the fragile X gene is linked to more cases of autism than any other gene, what we have learned from fragile X helps us to understand autism.”

Despite the strong overlap, “until now, we did not know why this mutated gene causes either condition,” Zhao says.

Mitochondria have long been known as a cell’s powerhouse, but their other roles in brain development are only gradually becoming clear. Healthy mitochondria allow neurons to create more energy and have greater electrical activity. Mitochondria also support the establishment of dendrites, axons and synapses, parts of the elaborate linkages that allow brain cells to communicate with each other.

“Although mitochondria play a role in many diseases,” Zhao says, “this is the first time mitochondria dysfunction has been directly implicated in fragile X syndrome.”

Minjie Shen, lead author and a postdoctoral fellow in Zhao’s group, also transplanted immature, human neurons into mouse brains. Because these cells were grown from cells donated by fragile X patients, they carried the fragile X mutation. In these mice, low levels of the fragile X protein, FMRP, were associated with high levels of damaging oxidative stress caused by a variety of oxygen-bearing molecules.

“This is the first time that human fragile X neurons have been studied in any living brain,” Zhao says. “And so this information is more relevant to human neural development than what we can see in lab dishes.”

“This is the first direct evidence that mitochondria dysfunction contributes to fragile X and autism. I hope it will open up new therapeutic developments.”
Xinyu Zhao

In a compelling demonstration of mitochondria’s role in fragile X symptoms, Zhao’s research group used a chemical that promotes mitochondria formation to reverse behaviors like hyperactivity and impaired social interaction in these mice.

The fragile X gene gains its power because it is a “regulator gene” that controls the action of dozens, even hundreds, of “downstream genes.” Indeed, the fragile X protein affects about 4 percent of messenger RNAs — compounds that “read” the genetic template of DNA to pattern new proteins.

The central finding of the new study, Zhao says, “is that we have discovered the first convincing mechanism that could explain the neurological impairment in fragile X, and that mechanism is defective mitochondria.”

Other developmental disorders, including Huntington’s disease, Rett syndrome and Down syndrome, seem to feature mitochondria dysfunction as well, she notes.

Mitochondrial mating: Function follows form

After a neuron distinguishes itself from its parent cells, the hundreds or thousands of mitochondria within engage in an elaborate dance, joining and separating in a dynamic balance that is vital to many biological functions. But with the fragile X mutation, “we see that the mitochondria are more fragmented, shorter and round rather than long and tubular, due either to decreased fusion or increased fission,” Zhao says.

The result is a neuron with impaired connectivity and less resistance to destructive oxidant chemicals.

“When we restored mitochondria fusion with gene editing or a chemical compound, we partly restored neuronal development,” Zhao says. “In mice lacking FMRP, we also rescued some behavioral deficits using the chemical treatment.

“This is the first direct evidence that mitochondrial dysfunction contributes to pathogenesis of fragile X,” she adds, “and I hope it will open new investigations and new therapeutic developments.”

Pinpointing a mechanism for fragile X is a first step to finding chemicals that might block or reverse that mechanism, Zhao says. Any treatment that is developed for these defects could be used after birth, during the period when neurons start to mature, Zhao says.

Although such a potential treatment is years away, the current study is a major advance for conditions that today lack treatments, Zhao says. “Human neuroscience seems to get more complex all the time, but I feel we’ve established a foothold that allows us to see the true source of difficulty in several serious neurological disorders. And that’s exactly our role as basic neuroscientists.”

This study was funded by the National Institutes of Mental Health, Child Health and Development, and Neurological Disorders and Stroke, and the John Merck Fund. Other UW–Madison collaborators on the study include Jason Vevea, Edwin Chapman and Anita Bhattacharyya.

 

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Save the dates: Public forums for VCRGE finalists  external link

Three dates and times for finalist presentations for the position of UW–Madison vice chancellor for research and graduate education have been set.

Finalists will visit campus over the next several weeks to interview, present their visions of the UW–Madison research enterprise, and meet with faculty, staff and students. Open forums for finalist presentations will be held:

  • Monday, Feb. 18, from 9 to 10 a.m.
  • Friday, March 1 from 9 to 10 a.m.
  • Tuesday, March 5 from 9 to 10 a.m.

All presentations will be in the Discovery Building’s DeLuca Forum.

Information on each finalist will be made available 48 hours prior to each forum presentation on the VCRGE search website. A reminder of forum events and the availability of finalists information will be published in a future Inside UW.

The search for a new vice chancellor to lead UW–Madison’s program of research and graduate education launched in September 2018. A 15-member committee charged by Chancellor Rebecca Blank and chaired by kinesiology Professor Dorothy Farrar-Edwards has been searching for a successor to Marsha Mailick, who retired last fall. The Office of the Vice Chancellor for Research and Graduate Education has been led by Interim Vice Chancellor Norman Drinkwater.

Blank will make the final decision on a new vice chancellor once the campus visits have been completed.

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Video: Stem cells, lab to clinic  external link

In the fourth and final video of our stem cell series, Forward Bio Institute director Bill Murphy and David Gamm, director of the McPherson Eye Research Institute, where stem cells are being turned into retinal cells to try to find cures for blinding disorders, explain how stem cell scientists are working with industry to put scientific breakthroughs on the path to helping patients.

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SSTAR Lab examining solutions for making higher education more affordable  external link

Photo: Nick Hillman standing outside the new SSTAR Lab offices.

Nick Hillman, an associate professor with the School of Education’s Department of Educational Leadership and Policy Analysis, will lead the new SSTAR Lab, which will conduct research into financial aid issues and seek solutions. Photo by Sarah Maughan

As concerns over student debt, college affordability, and access to high education have garnered increasing attention since the recession of a decade ago, UW–Madison’s Nicholas Hillman says there has been a growing community of researchers examining issues related to financial aid.

Perhaps surprisingly, however, Hillman notes that much of the work being done in this realm isn’t closely linked to financial aid offices and practitioners on the front lines who are working with students and their families on a consistent basis.

“The people who work in financial aid have to be aware of a range of policy, compliance and regulatory issues,” says Hillman, an associate professor with the School of Education’s Department of Educational Leadership and Policy Analysis. “As a researcher, if you don’t have insight into how financial aid works in a real-world setting, it’s going to have less of a practical impact.”

In an effort to conduct more meaningful research in this field, UW-Madison is launching the Student Success Through Applied Research (SSTAR) Lab. The lab is housed within the university’s Office of Student Financial Aid, located on the ninth floor of 333 East Campus Mall.

The lab is being led by Hillman, who says he is not aware of any other lab in the nation that is developing such a partnership with a financial aid unit.

“We’re being very intentional about connecting our research to practice,” Hillman says. “That’s the upside to our relationship with the Office of Student Financial Aid and it’s very exciting.”

The SSTAR Lab’s mission is to use applied academic research to guide, support, and partner with practitioners whose work aims to improve educational opportunities and outcomes for current and future college students.

Photo: Derek Kindle

Derek Kindle Photo: Bryce Richter

Although the SSTAR Lab has been conducting research and building physical lab space over the past year, it’s hosting a grand opening event on Friday, Feb. 8, the same day as the Office of Student Financial Aid’s annual open house. A short program — including a ribbon cutting ceremony for the lab and a new classroom space, and a comments from UW-Madison Chancellor Rebecca Blank, Director of Student Financial Aid Derek Kindle and Hillman — begins at 2 p.m.

“Having our team so closely engaged with the academic and research enterprise is not only exciting for our team, but we believe it is absolutely critical in pushing forward solutions to institutional, state, and national issues to related to higher education and access,” says Kindle.

The SSTAR Lab and Office of Student Financial Aid can already point to one major success with the unveiling last year of Bucky’s Tuition Promise, which covers tuition and segregated fees for nearly 800 students from Wisconsin who started classes at UW–Madison this past September.  Nearly one in five of UW–Madison’s incoming, in-state students is benefiting from Bucky’s Tuition Promise, making education at the state’s flagship much more affordable for state families.

The initiative, announced in February 2018, covers four years of tuition and segregated fees for any incoming freshman who is a Wisconsin resident and whose family’s annual household adjusted gross income is $56,000 or less — roughly the state’s median family income. Transfer students who are Wisconsin residents and who meet the same income criteria receive two years of tuition and segregated fees.

The 796 students covered under the commitment represent 65 of Wisconsin’s 72 counties. More than half (56 percent) are first-generation college students, meaning neither parent holds a four-year college degree. Nearly one-fourth (23 percent) are transfer students, with the rest being new freshmen.

“Bucky’s Tuition Promise was the first thing this lab worked on,” says Hillman. “It was an exciting idea: Could this university really afford to give free tuition to lower-income students across Wisconsin? So we started digging deep into the data and really looking at all the variables and costing things out. We were able to learn from other universities’ experiences and deliberately designed Bucky’s Tuition Promise in a way that, hopefully, is sustainable long-term.”

Up next, Hillman says the SSTAR Lab is focusing its work on finding better ways to diagnose problems in this realm — such as loan repayment rates — and then develop the most effective ways to measure such issues en route to suggesting and examining multiple solutions.

Photo: Offices of the SSTAR Lab.

The SSTAR Lab will have a grand opening event at 2 p.m. Friday, Feb. 8. UW-Madison

“By collaborating with practitioners on campus to develop and implement research projects that address specific needs, we believe this will help us develop evidence-based methods that can help institutions expand access and student success in lasting ways,” says Hillman, whose research sits at the intersection of college access and finance, namely in the areas of student financial aid and state higher education finance. “Our team will be collecting, managing and analyzing data with the goal of helping to improve policies and practices to better promote student success — particularly for underrepresented students.”

The Lab’s research team also includes graduate assistants Ellie Bruecker and Jacklyn Fischer, both of whom are pursuing doctorates through the Department of Educational Leadership and Policy Analysis. Bruecker’s research interests include examining student loan borrowing and repayment, Free Application for Federal Student Aid (FAFSA) filing, and the impact of high schools on college access. Fischer’s research centers on financial aid policy and college-to-workforce transitions.

“Working in the SSTAR Lab has really reshaped how I think about my research and what I want to do with it,” says Bruecker. “Being embedded in the financial aid office means we get to see the impact of our work in real-time, and that’s been really rewarding and motivating. The opportunity to learn from practitioners has given me a new understanding of the complexity of financial aid policy and the people who make those policies work for students.”

“In my previous work as a college advisor, I often saw how financial aid resources could open or close doors of opportunity for students,” says Fischer. “To be able to collaborate on research that can help open more doors is a privilege.”

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Study: No race or gender bias seen in initial NIH grant reviews  external link

Examinations of National Institutes of Health grants in the last 15 years have shown that white scientists are more likely to be successful in securing funding from the agency than their black peers.

A new study from the University of Wisconsin–Madison shows that bias is unlikely to play out in the initial phase of the process NIH uses to review applications for the billions of federal grant dollars it apportions annually to biology and behavior research, even though the reviewers at that early stage in the process are aware of each grant applicant’s identity.

Photo of Patricia Devine

Devine

“Absence of bias here does not mean there is no bias in the entire review process,” says psychology professor Patricia Devine, who secured NIH funding to assess the agency’s review process. “But we’re confident that this is a strong and valid result showing no evidence of bias against female and black scientists in this first review of grant applications.”

Their findings were published this week in the journal Nature Human Behavior.

A team of UW–Madison psychologists selected 48 actual grant proposals sent to NIH — half of which were awarded funding — and stripped them of any identifying information. Each study was reproduced four times with new fictitious names, information implying the applying scientist was a white man, white woman, black man or black woman.

They recruited more than 400 scientists with credentials qualifying them to serve as reviewers for grant applications submitted to NIH’s four largest institutes — most of whom had served as NIH reviewers, applied to NIH for funding, or both. Each volunteer reviewer received three of the experiment’s grant applications: two ostensibly written by white men, and one with names reworked to appear as authored by a black woman, black man or white woman.

The reviewers read the applications and returned detailed critiques as they would in an actual, initial NIH review, including scores in several areas (the most consequential being an “impact” score).

There was no consequential difference in the impact scores or the reviewers’ use of descriptive language that can be consequential for how grants are perceived — how they apportioned words like “diligent,” “fails,” “limits,” “convincing” or “remarkable” —  in their reports.

“That will be surprising to people. This is a place where people will assume there is bias,” says Devine. “But the reviewers were focused on the actual grants that were in front of them, and not the social categories of the applicants.”

The initial review phase may not be a likely step to favor a race or gender. The first assessment is an in-depth affair, with long, written justifications for judgments that don’t lend themselves well to the usual trappings of bias.

“We know from other areas of research related to bias that when people have a lot of information, take more time to think, and are more accountable for how they act, bias is less likely to show up,” says William T. L. Cox, a UW–Madison scientist. Cox and University of Arkansas professor Patrick S. Forscher were members of Devine’s lab and are co-authors of the study with Devine and UW–Madison psychology professor Markus Brauer.

Photo of William Cox

Cox

“We have captured the part of the review process where reviewers are taking the most time and paying the most attention,” Cox says. “So, it may be the area where we would least expect bias to appear.”

The researchers also found no difference in the treatment of high-scoring grants that NIH had actually funded and lower-scoring grants that missed out.

“The social science literature tells us that when things are ambiguous, men tend to get a bit of a bonus while women and black people are kind of downgraded,” Devine says. “We didn’t see that in the reviews supplied in this experimental study.”

The painstaking research took five years to complete, and included confirming the findings by applying more than 4,500 possible differences in analytical emphasis to the data. More than 97 percent of the time, the results showed no significant difference in treatment of applicants based on race or gender.

“But we don’t want to be understood to suggest that we don’t think there is any bias in the process,” says Devine, who admires NIH for supporting the kind of examination that could have uncovered a bias among reviewers evaluating grant proposals. “If there is bias, I don’t know yet where it is and how it manifests.”

In later steps in the grant review process, which can involve shallower analysis, sometimes brief debate and less individual accountability for reviewers, Cox points out, it’s more likely bias could creep in.

The bias seen in the apportionment of funding may not be built into the review process at all. Grant applications submitted by women and black scientists may be somehow different than those written by white men, the researchers suggested.

Letters of recommendation written on behalf of black scientists may undermine them in subtle ways relative to peers, for example. Editing help from overcompensating white or male colleagues may be less constructively critical. Women may be more cautious than men in their writing, including more qualifying statements and fewer bold claims.

“Those things would be important to know,” Devine says. “If anybody isn’t receiving careful training on how to engage effectively in this process and write grants in a way that increase their chances for funding, that’s something you could train people on and a way to turn the tide.”

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Microbes hitched to insects provide a rich source of new antibiotics  external link

Photo: An ant crawls.

A Cyphomyrmex ant. These fungus-growing ants harbored a microbe that made the newly discovered antibiotic cyphomycin. Photo by Alex Wild

Medicine was transformed in the 20th century by the discovery and development of antibiotics, the vast majority of which came from one source: soil bacteria.

But we seem to have tapped out that supply. Resistance by disease-causing pathogens to existing antibiotics is increasing, endangering millions of lives and costing billions of dollars. New surveys of soil bacteria tend to turn up old chemicals. And few pharmaceutical companies are developing new antibiotic drugs.

But the same class of bacteria that gave us many of our antibiotics, known as Streptomyces, makes a home not just in the soil but all over, including on insects. Cameron Currie, a University of Wisconsin–Madison professor of bacteriology, has shown that some of these insect-associated microbes provide their hosts with protection against infections, suggesting that insects and their microbiomes may be a rich new source of antibiotics for use in human medicine.

Researchers collected more than 2500 insects of all kinds from diverse habitats across North and South America to prospect for microbes that might produce novel antibiotics. Cameron Currie and Marc Chevrette

So with a team of collaborators, Currie set out to test that idea, thousands of times over. In an exhaustive search of microbes from more than 1,400 insects collected from diverse environments across North and South America, Currie’s team found that insect-borne microbes often outperformed soil bacteria in stopping some of the most common and dangerous antibiotic-resistant pathogens.

In their work, the scientists discovered a new antibiotic from a Brazilian fungus-farming ant, naming it cyphomycin. Cyphomycin was effective in lab tests against fungi resistant to most other antibiotics and combatted fungal infections without causing toxic side effects in a mouse model. The researchers have submitted a patent based on cyphomycin because of its effectiveness in these early tests, setting up the team to begin to do  the significant additional work required before cyphomycin could be developed into a new drug used in the clinic.

The study is the largest and most thorough to assess insect-associated microbes for antibiotic activity to date.

A closeup of a purplish antibiotic.

The Streptomyces bacteria that produced the new antibiotic cyphomycin shows off a purple hue. Photo by Caitlin Carlson

The work was published Jan. 31 in the journal Nature Communications. The study was led by Currie lab graduate student Marc Chevrette with collaborators in the UW–Madison School of Pharmacy, the UW School of Medicine and Public Health and several other institutions in North and South America.

Streptomyces evolved about 380 million years ago and have since diverged into many lineages, some of which are more commonly found in soil or associated with insects. That evolutionary distance means that insect-associated microbes have adapted to their own unique environmental contexts.

“It follows that if you look in a different evolutionary context, you find new chemistry,” says Chevrette.

To survey a large portion of insect diversity, the Currie team collected more than 2,500 species across all major groups of insects, including flies, ants and bees, moths and butterflies, beetles and more. About a third were collected in tropical landscapes, and another third from temperate climates, with the remainder from arctic or other regions.

“We could collect 400 insects in a few days,” says Currie, whose own collecting assignment took him to Hawaii in winter.

More than half of those insects harbored the right kinds of bacteria. In all, the insects provided more than 10,000 microbes to test. The team isolated another 7,000 strains from soil or plant sources.

Then came the experiments — a lot of them.

“The real power in our study is that we did it 50,000 times,” says Chevrette.

Those 50,000 trials tested each microbe’s ability to inhibit the growth of 24 different bacteria and fungi, many of which, like methicillin-resistant Staphylococcus aureus, better known as MRSA, pose serious threats to human health.

A greater proportion of insect-associated microbes were able to inhibit the growth of these bacterial or fungal targets than were microbes isolated from soil or plants.

With Professor of Medical Microbiology David Andes from the UW School of Medicine and Public Health, the researchers tested several dozen promising microbe strains for their ability to fight infections in mice. Extracts from these microbes effectively killed both bacterial and fungal pathogens, and few demonstrated toxic side effects.

Photo: An ant picks up a particle.

A Cyphomyrmex ant. These fungus-growing ants harbored a microbe that made the newly discovered antibiotic cyphomycin. Photo by Alex Wild

As a further proof of concept, the team worked with School of Pharmacy professor Tim Bugni to purify cyphomycin and determine its chemical structure. Cyphomycin was able to treat infection in mice by Candida albicans, an opportunistic fungal pathogen that often infects immunocompromised people. Cyphomycin also showed low toxicity in mice.

By demonstrating effective antimicrobial action and low toxicity in mice, the researchers have passed the first barrier to developing new antibiotics for clinical use in humans. But many promising drugs fail further along in development, which is why it is important to identify multiple candidate antibiotics in the early stages.

Currie’s team isn’t surprised that insect-associated microbes are a promising source of novel antibiotics. For one, they say, insects may help select for antibiotics that are not toxic to animals. And because many insects rely on microbial antibiotics to combat ever-evolving pathogens in their own environment, they have likely selected for antibiotics that can overcome common resistance mechanisms.

“The insects are doing the prospecting for us,” says Currie.

This work was supported by the National Institutes of Health (grants U19 Al109673, U19 TW009872, and National Research Service Award T32 GM008505) and the National Science Foundation (grant MCB-0702025).

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Enter your best science images in the 2019 Cool Science Image Contest  external link

Science relies on data, and some of the most striking data produced at the University of Wisconsin–Madison is visual.

Students, staff and faculty on campus employ microscopes, telescopes, cameras and scanners to make the world — even the parts our eyes can’t perceive — visible, understandable and often beautiful.

To recognize the visual and exploratory value of scientific imagery, the 9th annual Cool Science Image Contest is soliciting the best images from members of the UW–Madison community.

Sponsored by Promega Corp. with additional support from the UW–Madison Arts Institute and DoIT Digital Publishing and Printing Services, the Cool Science Image Contest offers an opportunity to show off compelling science images made by students, staff or faculty.

More than 170 images and videos — depicting animals, insects, plants, cells, stars, weather and nanoscale compounds — were entered in last year’s contest. Submissions are featured on university websites and other communications, and in exhibits on and off campus. Ten winning images and two winning videos are also showcased in a fall exhibit at the Mandelbaum and Albert Family Vision Gallery of the McPherson Eye Research Institute, and at Promega’s Fitchburg headquarters.

To enter your cool science images or videos, visit the contest webpage for guidelines, submission requirements and a link to the entry form. The submission deadline is March 15.

Winners, chosen by judges with experience in scientific imagery and visual art, will be announced in April. Each winning entry receives a $100 Downtown Madison gift card and a poster-size print of the submission. All qualified entries will be displayed in a slide show at the 2019 Wisconsin Science Festival and during the exhibit at the McPherson Eye Research Institute.

See the 2018 winners.

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As the climate warms, tens of thousands of lakes may spend winters ice free  external link

Image shows the zones where lakes will become intermittent-ice lakes, based on the temperature rise.

In many parts of the Northern Hemisphere, frozen lakes define the winter experience and create an indelible sense of place. From ice fishing and hockey to skating, skiing and snowmobiling, icy lakes enable communities to engage in activities that aren’t possible in warmer seasons or climates.

But these iconic cold-weather past-times could become a rare winter treat. A new study published today [Jan. 28, 2019] by an international team of researchers, including at the University of Wisconsin–Madison, shows that many northern latitude lakes are at risk of experiencing some ice-free winters in the coming decades. In some places, lake ice will disappear altogether by the end of the century.

According to its authors, the study — led by Professor Sapna Sharma of York University — offers “the first global estimate of how many lakes are likely to lose winter ice cover as climate warms.”

Co-author John Magnuson, emeritus director of the Center for Limnology at the University of Wisconsin-Madison, says the team developed a model that allowed them to predict which lakes would lose ice first and how that ice loss would be distributed across different latitudes.

Photo: A thawed Lake Mendota in January.

Lake Mendota thaws in January after an initial freeze in December. Northern lakes are experiencing fewer frozen days and are likely to experience more ice-free winters as the climate warms. Photo by Adam Hinterthuer

The result is a map that shows the extent of winter lake-ice retreat under different global warming scenarios and highlights what could still be saved through efforts to reduce global emissions.

Currently, 15,000 lakes sit in a climate zone where they experience intermittent lake ice – some years are cold enough that the lakes freeze over and other years are warm enough that they don’t. These lakes, the researchers write, are a “harbinger of permanent ice loss.” As annual average air temperatures warm, this intermittent ice zone moves north, eventually leaving the lakes south of it looking at an ice-free future.

If the world can meet the Paris Agreement’s climate mitigation goals to limit global average temperatures to two degrees Celsius of warming, the study predicts the number of these intermittent ice lakes will increase to 35,300, potentially disrupting the winter experience and traditions of the 394 million people who live within an hour’s drive of their shores.

However, under a “worst-case” climate scenario of eight degrees Celsius warming ­(predicted by some models as the extreme case if the world does not act to reduce its greenhouse gas emissions) the number of intermittent-ice lakes jumps to 230,400, bringing lake ice impacts close to home for 656 million people spread across more than 50 countries.

Such an extreme level of warming would push winter’s ice-covered lake zone out of the United States, well north into Canada, and endanger the ice-cover of most lakes in traditionally frigid countries like Norway and Sweden.

Photo: People ice skate on frozen Lake Mendota.

People ice skate on Lake Mendota on Jan. 16, 2019. The lake froze on Dec. 15, 2018, reopened on Dec. 21, 2018, and then froze again on Jan. 10, 2019. Northern lakes are experiencing fewer frozen days and are likely to experience more ice-free winters as the climate warms. Photo by Kelly April Tyrrell

It’s important to note, says Sharma, that these changes are happening now: “It’s not one of these climate change predictions where you think, ‘Oh, I have 100 years before this might become my reality,’” she says.

From 1862 through the winter of 1996, southern Wisconsin’s Lake Geneva, a prime destination for regional ice fishermen, froze over each year. But, since 1997, the lake has had four ice-free winters. Lakes from Alaska to Germany and Japan are experiencing similar trends.

For instance, over the last three decades, Japan’s Lake Suwa has only been freezing two out of every 10 years. Lake ice records here — the longest-running in the world — go back to 1400 AD and in the first 250 years that data was collected, there were only three years in which the lake did not freeze.

The drastic changes in Earth’s climate over the last several decades do more than limit human recreation on frozen lakes, the study authors say. Lakes that don’t freeze over are more susceptible to evaporative water loss during the winter, and warm up faster through spring and summer. This can lead to lower water levels, an increase in potentially harmful algal blooms, and reduced oxygen levels in the water, which can be detrimental to fish and other wildlife. It also threatens human use for drinking water, boating and fishing.

The study also found that once regional winter air temperatures reach an average of 8.4 degrees Celsius (about 47 degrees Fahrenheit), lakes tend not to freeze. Lakes don’t all respond to warming equally, Magnuson says.

“The deeper the lake is, the more heat storage it has and it takes more cold weather to get the lake down to a temperature where it could freeze,” he says.

A lake’s shoreline also plays a role. The study found that lakes with “simpler” or more circular shorelines receive greater wind shear across their surfaces, which can prevent the formation of ice because it requires calm, flat water.

Magnuson saw these dynamics in action this year. From his office on the shore of Lake Mendota, the deepest of Madison, Wisconsin’s chain of lakes, he watched as the lake froze and thawed twice in December and January. Meanwhile, nearby and smaller Lake Wingra froze in early December and has maintained its ice. Mendota’s “fits and starts freezing,” he says, illustrates how climate change is expected to affect northern lakes.

“Lake Mendota’s not going to suddenly have no ice and then have no ice again the next year,” he says. “It’s going to have increasing proportions of years with no ice. It will have good winters for ice activity and winters with no ice activity. This is going to be a gradual process.”

It means millions of people will find themselves awaiting the big winter freeze they have come to depend on and turn to each other to ask: “Winter is coming … right?”

The study was supported by the Ontario Ministry of Research, Innovation and Science Early Researcher Award, the York University Research Chair program, the Natural Sciences and Engineering Research Council of Canada, the Department of the Interior Northeast Climate Science Center, and the North Temperate Lakes Long-Term Ecological Research program.

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As climate heats up, rising rainfall averages hide crop-killing droughts  external link

Research performed in the Ethiopian highlands shows that even in years with above average rainfall, crops can be severely reduced by drought early in the growing season, when seeds must sprout and get established.

Photo: Sorghum field

Much of the Ethiopian highlands are blanketed in rich soils, but sloping land combined with an intense rainy season can cause widespread erosion. The crop in the center is probably sorghum. Photo: Michael Eggen

A study by University of Wisconsin–Madison scientists Michael Eggen and Mutlu Ozdogan, now online at Environmental Research Letters, looked at yields of sorghum, a crop related to corn that is prized for its drought resistance.

The study showed a paradoxical result: Even though climate change “will bring generally warmer and wetter seasons to the study area,” the report said, droughts early in the growing season “will likely have negative impacts on sorghum yield.”

Photo: Mutlu Ozdogan

Ozdogan

Photo: Michael Eggen

Eggen

That phenomenon is already visible in the years with a strong El Niño, the thermal cycle in the Pacific Ocean that affects weather worldwide. As the climate as a whole warms, these droughts are likely to become both more common and more intense in Ethiopia’s highlands.

The study had its roots in conversations that Eggen had in 2015 while working on a larger project on the relationship of agriculture to environment and climate in Ethiopia, a project led by Ozdogan, an associate professor of forest and wildlife ecology at UW–Madison.

Photo: People gathered around a stove

Sorghum is rotated in the field with the indigenous grain tef. Tef is the favored grain for making injera, the local flatbread, seen here being cooked on wood-fired stove. Photo: Michael Eggen

“I lucked out,” says Eggen. “This was right after the strong El Niño of 2015. I was talking with farmers about the last couple of seasons, without intending to focus on extreme weather, but they all told me that 2015 was the worst year ever, worse than the major famines of 1983 and 1998. ‘We have never seen sorghum fail at this scale,’ they told me.”

Sorghum is renowned in the area as a drought-resistant, subsistence crop, Eggen notes, “so when sorghum fails, it’s bad for everyone.” Eggen, who has now been working in Ethiopia for about 12 years and speaks “passable” Amharic, says sorghum is used for food, animal feed and brewing beer.

“The farmers told us that the failure was because the rains had not come early in the growing season and the seedlings died or did not even emerge,” Eggen says.

Photo: Farmer plowing with oxen

A farmer plows his sorghum field to plant again after early rains failed. Photo: Ben Zaitchik

While examining climate records, Eggen and Ozdogan noted that the El Niño years generally had below average rainfall during the growing season, much like the forecasts for climate change — which also indicate that El Niños will become either more frequent, more intense, or both.

In the study, the impact of El Niño today served as a stand-in for a projected 3 to 4 degree Celsius increase in temperature later in the century, Eggen says, but El Niños will not disappear as warming continues. “Down the line, we have two synergistic factors: the intensified El Niño, and the substantial warming. Either can cause catastrophic sorghum failure, and both of them together are much more likely to cause those failures — even before the full 3 to 4 degrees of warming is evident.”

“… if the new climate includes drought during the critical early weeks of the growing season, the result will be more crop failures, possibly famine.”

Michael Eggen

Although crop yield projections based on changes in average temperature and rainfall generally forecast more declines in tropical rather than temperate regions, portions of the Ethiopian Highlands have been expected to see the opposite trend, Eggen and Ozdogan explain. In that region, a warming climate with bountiful rains at high elevation might increase yields.

But that is not what the researchers found, based on using El Niño as a harbinger of a warming future. “We confidently expect hotter temperatures, and more total rainfall,” says Eggen. “But if the new climate includes drought during the critical early weeks of the growing season, the result will be more crop failures, possibly famine.”

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New method assesses lead hazard in soil  external link

Vegetable gardens located close to buildings painted before 1978 may contain lead. The new soil placed in these raised beds should reduce any lead exposure. Photo by David Tenenbaum

As Milwaukee, Flint, Michigan and other cities grapple with the toxic impact of lead water pipes, another lead-contamination hazard lurks in soil.

The nervous-system damage of lead is irreversible and intolerable, and so preventing exposure is the only real defense.

Not all lead compounds are created equal, in terms of how easily they move from the soil, both inside and outside the lab. Yet standard tests for lead in soil do not give a full picture of bioaccessibility.

Photo: Peeling paint on a porch ceiling.

Lead paint is not always as obvious as this. Paint flaking from walls can contaminate soil within 20 feet of a building. Creative Commons

In a study published Oct. 12 in Environmental Science and Technology, University of Wisconsin-Madison researchers describe a way to use a common, low-cost soil test to determine how much of the lead is bioaccessible, and therefore dangerous.

A second factor in determining the hazard of lead in soil, called bioavailability, measures how easily it can move from the gastrointestinal tract into the bloodstream.

Although the terminology is confusing, Douglas Soldat, a lead expert and professor of soil science at the University of Wisconsin-Madison, says they tend to be related: A bioaccessible lead compound is usually bioavailable as well. Because lead is extremely toxic, immobilizing it in soil and reducing its uptake in the gastrointestinal tract both benefit public health.

The test described by Soldat and his former graduate student Shannon Plunkett focuses on lead phosphate, which is relatively insoluble soil. Lead carbonate, a pigment historically used in paint, binds less tightly and therefore is more mobile in the soil. “If our goal is to keep lead out of the body, the less soluble forms are more desirable,” says Soldat.

The new testing approach uses the Mehlich 3, an existing and affordable soil-nutrient test, to evaluate lead bioaccessibility. By simultaneously measuring total lead and Mehlich-3 lead, it’s possible to estimate what percentage is immobile.

Lead was found in house paint until 1978 and frequently remains in soil near foundations, posing a threat to vegetable gardeners and playful children.

In Southwest Wisconsin, more than a century of lead mining has left ground-level hot spots where lead ore was extracted, processed or shipped.

The analytical tactic explained in the new study could be used by homeowners or tenants concerned about lead in soil, or by landowners in areas of known or suspect lead contamination.

The new analysis based on Mehlich 3 could also be used to evaluate a growing tactic for immobilizing lead: adding phosphorus to soil to increase the formation of low-mobility lead phosphate. The strategy, called in situ (on site) remediation, has been applied to broadly polluted areas where soil removal or “capping” is not feasible.

Phosphorus addition has shown promise in hundreds of studies, notes Plunkett, but the results depend on many factors, including the type of phosphorus used and soil properties like acidity. Until now, measuring how much lead-phosphate remediation affects mobility using EPA-approved tests, which cost about $200 per sample, has been a difficult and expensive proposition.

The Mehlich 3 results that Soldat and Plunkett reported closely paralleled the Environmental Protection Agency’s “1340” test, which is the accepted way to assess lead bioaccessibility, but at a much lower cost.

The Mehlich 3 test and total lead tests are offered at the University of Wisconsin Soil and Forage Laboratory and the Milwaukee Health Department Laboratory.

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