biomineralization to build structurally ordered and environmentally adaptive composite materials. While research teams have significantly improved biomimetic mineralization research in the lab, it is still difficult to engineer mineralized composites with structural features and living components much like their native counterparts. In a new report now published on Nature Chemical Biology, Yanyi Wang and a research team in physics, advanced materials, synthetic biology, and engineering in China, developed living patterned and gradient composites inspired by natural graded materials. They coupled light-inducible bacterial biofilm formation with biomimetic hydroxyapatite (HA) mineralization in this work, to show how the location and degree of mineralization could be controlled. The cells in the composites remained viable while sensing and responding to environmental signals. The composites showed a 15-fold increase in Young’s modulus (i.e., stiffness, the ratio between stress and strain) after mineralization. The work sheds light to develop living composites with dynamic responsiveness and environmental adaptability.
previous experiments, they selected protein Mefp5 – originating from Mytilus edulis, followed by Mfp3S – originating from Mytilus californianus and another variant of the Mfp3S peptide (Mfsp3S-pep) to initiate mineralization and promote adhesion. The team constructed fusion proteins containing a major protein domain of the E. coli biofilm to form CsgA-Mfp fusion proteins and confirmed their potential secretion from engineered cells. They then selected the CsgA–Mfp3S-pep fusion protein as a representative for hydroxyapatite mineralization and conducted experiments to verify the function of the protein to highlight their role during mineralization and crystal formation. Thereafter, Wang et al. constructed a light-inducible biofilm-forming strain named lightreceiver-CsgA-Mfp3S-pep that can be tightly regulated via blue light illumination.
The light-sensitive strain could generate functional biofilm materials after illumination with light to promote the mineralization of hydroxyapatite (HA). To validate this, the scientists exposed the light-sensitive strain to blue light in a Petri dish and used histological staining and transmission electron microscopy (TEM) imaging to show the production of amyloid fibers in the biofilms. Comparatively, they did not observe amyloid fibers in samples grown in the dark. The engineered extracellular matrix also acted as a template for HA mineralization in time, which they confirmed after 7-days of incubation based on X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS) techniques.
scanning electron microscopy. The light-regulated approach controlled the shape of the composite based on grid-pattern projections and spatial resolution of light in the microscale—comparable to the size of the living bacteria. The team then verified the viability of live, intact cells by engineering the living composites to express fluorescent proteins, as confirmed using confocal microscopy images. Thereafter, they used thermogravimetric analysis to quantify the inorganic components of mineralized composites, where the inorganic material increased proportionally with time on immersion in simulated body fluid (SBF). Wang et al. also compared the Young’s modulus of the biofilm using a micro-indentation technique to show how mineralization strengthened the E. coli biofilms to protect the cells.
Density controlled gradient composites
the need to precisely identify between hard and soft tissues for successful physiological performance, therefore the light intensity could be tuned to control the density and mechanical properties of engineered living materials. Zhang et al. accomplished this by exposing E. coli cultures to different intensities of illumination to reveal how biofilm thickness decreased with the decreasing intensity of blue light. They further showed how mineralization was tightly and locally directed by the engineered Mfsp3S-pep fusion proteins. Then they studied the local mechanical properties of illuminated regions with micro-indentation to observe a fourfold increase in Young’s modulus to highlight living composites engineered with tunable mineral gradients and mechanical properties for regenerative tissue-to-bone interfaces in bone tissue engineering applications.
Deploying living composites for site-specific damage repair
The scientists also studied the capacity for the engineered biofilms to aggregate for damage repair by gluing polystyrene microspheres, alongside HA-mineralization. As proof-of-concept, they applied living mineralized composites to fill and repair cracks engineered on the surface of a polystyrene Petri dish. During the experiments, the light-induced adhesive biofilms captured microspheres in solution to fill the purposely created damaged furrow, while nanofibers in biofilms acted as a template for hydroxyapatite mineralization to consolidate light-induced cementation under blue light illumination. Using scanning electron microscopy, Wang et al. showed how bacteria and the surrounding extracellular matrix adhered together with microspheres to illustrate the adhesive function of the living biofilms. The HA-mineralized composites formed dense, concrete-like layers that filed the damaged furrow to highlight the mineralization functionality of the living composites for enhanced durability and repair applications.
Wang Y. et al. Living materials fabricated via gradient mineralization of light-inducible biofilms, Nature Chemical Biology, doi: doi.org/10.1038/s41589-020-00697-z
Kröger N. et al. Self-assembly of highly phosphorylated silaffins and their function in biosilica morphogenesis, Science, 10.1126/science.1076221.
Davis S. A. et al. Bacterial templating of ordered macrostructures in silica and silica-surfactant mesophases. Nature, doi.org/10.1038/385420a0
The coronavirus has taught us an important lesson.
“The pandemic has shaken the entire system. Migrant workers weren’t allowed in. Production dropped and people were afraid that the fields wouldn’t be sown or harvested. A number of steps were taken to limit the effects, including separate entry rules for agricultural workers. This demonstrated the important role of migrant workers in the European food industry,” says Johan Fredrik Rye, professor in NTNU’s Department of Sociology and Political Science.
In Norway, the state wanted to stimulate farmers to entice domestic labor to take on the spring planting and fall harvesting of this year’s crop. In the UK, Prince Charles was at the forefront of trying to get the English to go out into the fields.
Both attempts were unsuccessful.
“The challenge is that migrant workers do the jobs that a country’s own population no longer wants to do. These are jobs that are often poorly paid, poorly regulated, monotonous, dirty and sometimes dangerous,” says Rye.
When migrant workers take over manual jobs, the status of those jobs drops further and makes them even less attractive to local people. The emphasis is more on the employer’s needs than on the employee’s right to a decent job, according to the migrant researcher.
Karen O’Reilly and Rye teamed up to edit the recently published book titled International Labor Migration to Europe’s Rural Regions.
The book includes contributions from a number of research groups that have studied different aspects of the diverse labor migration patterns in Europe.
Migrant workers range from Russians and Poles in the Norwegian fishing industry, Polish seasonal workers in container barracks on German farms and Thai berry pickers in Swedish forests, to Ukrainian farm workers in Poland, Eastern European strawberry pickers in Norway and England, Albanians in Greek agriculture and shepherds in the Mediterranean countries.
Two chapters compare American and European agriculture.
Rye and O’Reilly are clear on what the research shows: migrant workers and seasonal workers are marginalized, invisible and exploited.
“Poor working conditions and low status characterize Norwegian rural communities more than before and will continue to do so. Migrant workers often find themselves in the marginal zone of the regulated labor market, both in Norway and elsewhere in Europe,” says the sociologist.
“A lot of people are trying to change these conditions, but it’s tough, even when you try to pass laws to regulate working life. The problems lie more with how global food production is organized than in the unwillingness of individual employers.”
Change is difficult because farming needs to be profitable, so the wage level has to be kept low.
Consumers are happy to say yes when asked if they would be willing to pay a little more for their food if it were produced in a more responsible way, but when they’re actually shopping they opt for the cheapest choice. It’s not easy to do anything about that, says the professor.
According to Rye, migrant workers are expected to work hard—and settle for little.
Poles in Norway are said to be ideal workers despite the fact that their living conditions are poor and isolated. We find similar situations all over the European continent. For example, Romanian strawberry pickers in Andalusia are housed in rooms with anywhere from two or six others. They’re far from home and are only minimally integrated into the host culture.
Common to the various host countries is that the authorities ignore the migrants’ poor working and living conditions. Recruitment companies minimize the possibility of employees participating in collective bargaining schemes.
“Working life in Norway is among the most regulated in Europe. It’s a good starting point. But at the same time, the state’s attention has been less focused on some parts of working life in the rural districts. The labor market in rural areas may seem more immune to attempts at state regulation, making migrant workers’ ability to organize that much harder,” says Rye.
More than almost any other industry, food production depends on migrant workers. Employers defend low wages by saying that migrants earn much more than they would in their home country.
“The system maintains an idyllic picture of a triple-win from labor migration: the employer gets good, cheap labor, the employee earns more than at home, and the family and home country benefit from it,” says Rye.
Rye points out that major geopolitical changes have influenced labor migration in Europe. The fall of communism, EU expansion, globalization and the dismantling of national borders have enabled extensive labor migration. Cheap flights have made it easy to get around. In theory, you could live in Gdansk and commute weekly to Norway. The book refers to the fact that there are 5.5 million migrant workers in Europe, and says that the actual number is probably even higher.
Agriculture in the United States is highly industrialized. The country’s two million farmers produce as much as 10 million farmers do in the EU. American working life is also far less regulated, less unionized and the welfare schemes much worse than in Europe.
Rye says that large parts of the agricultural and food production sectors in Europe are heading into similar industrialization at full speed.
“This is most evident in labor-intensive fruit and vegetable production in the Mediterranean countries, such as in southern Spain, where a 450 square kilometer area is covered with plastic for growing vegetables,” he says.
“But agriculture is becoming much more centralized in Norway too. Small farms are dying out and being replaced by much larger enterprises. This development sets the stage for bringing in more farm workers from abroad,” Rye adds.
Labor migration has a lot to do with emotions, says the professor. Migrant workers’ driving force is most often the hope of a better life for themselves and their families. But for many of them, it’s a demanding life, even if they make more money than at home.
The jobseeker leaves home and often has to live in a shared household. That might not pose a problem for a young Swede who’s spending a few months cleaning crabs on the Norwegian coast. It’s something else for a father with three children back home in Poland.
“Migrant workers live a kind of shadow life. They aren’t at home nor are they part of the community they’ve come to for work. Right-wing populism in Europe is strongest in rural areas, which probably affects migrant workers in some countries. The main impression in the Norwegian debate, however, is that people have a positive view of labor migration from Eastern Europe,” says Rye.
The researchers’ use a broad definition of “migrant worker.” It includes Poles who have worked in fish processing on Frøya island for ten years and Thai berry pickers who comb Scandinavia’s forests for a few weeks.
A high percentage of those who come to Norway as refugees also end up in low-paying agricultural jobs or in the food industry in rural areas. Getting a job without a Norwegian education and with poor language skills is difficult.
International Labour Migration to Europe’s Rural Regions, edited by Johan Fredrik Rye and Karen O. Reilly, Routledge.
Pandemic has revealed our dependence on
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In a first-of-its-kind study within cycad horticulture literature, University of Guam researchers have found that the use of anti-transpirants neither help nor hinder successful propagation of cycad stem cuttings.
The Guam-based study, published Oct. 22 in the journal Tropical Conservation Science, investigated whether retaining leaves during the propagation of cycad stem cuttings conferred any benefit to propagation success. Additionally, two anti-transpirant products were utilized to investigate their efficacy during the propagation process.
Leaves perform a variety of critical functions for plants, including the transport of water and nutrients from the roots via transpiration, the synthesis of useful sugars via photosynthesis, and the reduction of water loss via the closing of stomata, or little openings on the undersides of the leaves. Horticulturists sometimes manipulate these openings to the plant’s benefit.
Anti-transpirants are products used in the commercial fruit industry to reduce water demands during periods of drought and have been shown to be useful during grafting trials of some plants. Some of these products work by coating the stomata, preventing the escape of gases and thereby water loss. Others purportedly induce chemical reactions within the plant to help reduce water loss. One of each type of anti-transpirant was used for the studies.
The study tested the use of anti-transpirants on two species of Zamia cycads.
“To our knowledge no anti-transpirant product has ever been used on any cycad species prior to these studies,” said Benjamin Deloso, a cycad specialist who led the study as part of his master’s thesis at UOG.
Numerous traits were measured throughout the duration of the study, including the speed of adventitious root formation, the behavior of the retained leaves, the date of first leaf emergence, and plant survival.
The results revealed that leaf retention on stem cuttings yielded no beneficial or detrimental influence on propagation success or the speed of adventitious root formation and that when cycad plants are healthy, regeneration of roots and leaves is possible from stem cuttings when under the care of an experienced cycad horticulturist.
“You can think of a healthy cycad stem as a bank account. Even if you experience some losses—loss of roots or leaves—you still have reserves in the account that can be used to recover,” Deloso said.
The University of Guam continues to publish original research and expand knowledge on cycads, the world’s most threatened plant group.
Although this latest research did not include Guam’s native cycad, Cycas micronesica, known locally as fadang, the research is of interest to its conservation.
“As a native CHamoru, I am concerned about the state of Guam’s environment,” said C.J. Paulino, an environmental science graduate student at UOG and a co-author of the study. “Given the decline of the island’s native fadang, I was happy to contribute to research that would benefit its conservation.”
Benjamin E. Deloso et al, Leaf Retention on Stem Cuttings of Two Zamia L. Species With or Without Anti-transpirants Does Not Improve Adventitious Root Formation, Tropical Conservation Science (2020). DOI: 10.1177/1940082920966901
Anti-transpirant products unnecessary in cycad propagation (2020, December 30)
retrieved 2 January 2021
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813 years of annual river discharge at 62 stations, 41 rivers in 16 countries, from 1200 to 2012. That is what researchers at the Singapore University of Technology and Design (SUTD) produced after two years of research in order to better understand past climate patterns of the Asian Monsoon region.
Home to many populous river basins, including ten of the world’s biggest rivers (Figure 1), the Asian Monsoon region provides water, energy, and food for more than three billion people. This makes it crucial for us to understand past climate patterns so that we can better predict long term changes in the water cycle and the impact they will have on the water supply.
To reconstruct histories of river discharge, the researchers relied on tree rings. An earlier study by Cook et al. (2010) developed an extensive network of tree ring data sites in Asia and created a paleodrought record called the Monsoon Asia Drought Atlas (MADA). SUTD researchers used the MADA as an input for their river discharge model.
They developed an innovative procedure to select the most relevant subset of the MADA for each river based on hydroclimatic similarity. This procedure allowed the model to extract the most important climate signals that influence river discharge from the underlying tree ring data.
“Our results reveal that rivers in Asia behave in a coherent pattern. Large droughts and major pluvial periods have often occurred simultaneously in adjacent or nearby basins. Sometimes, droughts stretched as far as from the Godavari in India to the Mekong in Southeast Asia (Figure 2). This has important implications for water management, especially when a country’s economy depends on multiple river basins, like in the case of Thailand,” explained first author Nguyen Tan Thai Hung, a Ph.D. student from SUTD.
Using modern measurements, it has been known that the behavior of Asian rivers is influenced by the oceans. For instance, if the Pacific Ocean becomes warmer in its tropical region in an El Nino event, this will alter atmospheric circulations and likely cause droughts in South and Southeast Asian rivers. However, the SUTD study revealed that this ocean-river connection is not constant over time. The researchers found that rivers in Asia were much less influenced by the oceans in the first half of the 20th century compared to the 50 years before and 50 years after that period.
“This research is of great importance to policy makers; we need to know where and why river discharge changed during the past millennium to make big decisions on water-dependent infrastructure. One such example is the development of the ASEAN Power Grid, conceived to interconnect a system of hydropower, thermoelectric, and renewable energy plants across all ASEAN countries. Our records show that ‘mega-droughts’ have hit multiple power production sites simultaneously, so we can now use this information to design a grid that is less vulnerable during extreme events,” said principal investigator Associate Professor Stefano Galelli from SUTD.
Hung T. T. Nguyen et al, Coherent Streamflow Variability in Monsoon Asia Over the Past Eight Centuries—Links to Oceanic Drivers, Water Resources Research (2020). DOI: 10.1029/2020WR027883
Largest study of Asia’s rivers unearths 800 years of paleoclimate patterns (2020, December 30)
retrieved 2 January 2021
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Even as vaccines are being rolled out to battle the coronavirus, wordsmiths at Lake Superior State University in Michigan’s Upper Peninsula say they want to kick any trace of it from the English language.
“COVID-19” and “social distancing” are thrown in with “we’re all in this together,” “in an abundance of caution” and “in these uncertain times” on the school’s light-hearted list of banned words and phrases for 2021.
Out of more than 1,450 nominations sent to the school, about 250 words and terms suggested for banishment due to overuse, misuse or uselessness had something to do with the virus.
Seven of the 10 selected are connected to the virus, with “COVID-19” leading the way. “Unprecedented,” which was banished back in 2002, has been restored to the list.
“To be sure, COVID-19 is unprecedented in wreaking havoc and destroying lives,” Banished Words List committee members said Thursday in a release. “But so is the overreliance on ‘unprecedented’ to frame things, so it has to go, too.”
The school in Sault Ste. Marie has compiled the list each year since 1976 it says to “uphold, protect, and support excellence in language by encouraging avoidance of words and terms that are overworked, redundant, oxymoronic, clichéd, illogical, nonsensical—and otherwise ineffective, baffling, or irritating.”
So far, more than 1,000 words or phrases have made the list. Nominations come from across the U.S. and a number of other countries.
Joining past inductees such as “absolutely,” “BFF,” “covfefe,” and “yuh know” are:
— COVID-19 (COVID, coronavirus, Rona). “A large number of nominators are clearly resentful of the virus and how it has overtaken our vocabulary,” the committee wrote. “No matter how necessary or socially and medically useful these words are, the committee cannot help but wish we could banish them along with the virus itself.”
— Social distancing. “This phrase is useful, as wearing a mask and keeping your distance have a massive effect on preventing the spread of infection,” members said. “But we’d be lying if we said we weren’t ready for this phrase to become ‘useless.'”
— We’re all in this together.
— In an abundance of caution (various phrasings).
— In these uncertain times (various phrasings).
— Pivot. “Reporters, commentators, talking heads, and others from the media reference how everyone must adapt to the coronavirus through contactless delivery, virtual learning, curbside pickup, video conferencing, remote working, and other urgent readjustments,” the committee wrote. “That’s all true and vital. But basketball players pivot; let’s keep it that way.”
— Karen. “What began as an anti-racist critique of the behavior of white women in response to Black and brown people has become a misogynist umbrella term for critiquing the perceived overemotional behavior of women,” the committee said.
— Sus, short for “suspicious.”
— I know, right?
“Real-world concerns preoccupied word watchdogs this year, first and foremost COVID-19, and that makes sense,” Lake Superior State President Rodney Hanley said in the release. “In a small way, maybe this list will help ‘flatten the curve,’ which also was under consideration for banishment. We trust that your ‘new normal’—another contender among nominations—for next year won’t have to include that anymore.”
Olivia Hinerfeld’s dog Lincoln and Kate Hilts’ cat Potato have something in common: They both like to interrupt Zoom calls as their owners work from home.
“Sometimes it’s better to preemptively put him on your lap so he can fall asleep,” says Hilts, a digital consultant in the Washington D.C. area.
Jealous of the attention that Hinerfeld is paying to her video conference call, Lincoln, a golden retriever, will fetch “the most disgusting” tennis ball he can find from his toy crate to drop into the lap of the Georgetown University Law School student.
For many dogs, this is life as it was meant to be: humans around 24/7, walks and treats on demand, sneaking onto beds at night without resistance. Cats—many of whom, let’s be honest, were already social distancing before humans knew what that was—are more affectionate than ever, some now even acting hungry for attention.
Ten months into quarantines and working from home because of the pandemic, household pets’ lives and relationships with humans have in many cases changed, and not always for the better. With this month’s U.S. rollout of vaccinations offering hope for normalcy in 2021, long-term impacts aren’t known.
“If we think how much time most of our pets prior to the pandemic typically would spend without people around to 24 hours a day, seven days a week, it’s quite a lot,” says Candace Croney, a Purdue University professor who teaches about animal behavior.
While estimates vary on how many pets there are in the United States, there’s general agreement that the majority of U.S. households have at least one pet, with dogs, then cats, far out-numbering other pets such as birds and fish. There also was a surge in pet adoptions this year as stay-at-home restrictions took effect.
For all those tens of millions of dogs and cats, it’s been an opportunity to teach humans a thing or two about themselves.
Croney has enjoyed watching how her long-hair cat Bernie and Havanese-mix dog Des play together. She finds herself getting “bookended” by the pair in bed at night.
“I’ve been learning things that I probably had been missing about how these two interact with each other and have found out that I need to take my cues from them,” Croney says. “Which is funny, because I do this for a living and this is the kind of thing we tell other people to do and clearly, I was missing some of it myself.”
In the Washington D.C. area, Emily Benavides, a U.S. Senate staffer, is learning her cat’s language. Humito (Spanish for Smokey), the 3-year-old rescue cat she’s had most of his life, has different-sounding “Meows” to communicate that he wants to eat, wants to nap or has knocked his toy under the refrigerator.
“I think the more time you spend with them, the more you can see them eye-to-eye,” she says. “The pandemic has brought us closer together.”
Devika Ranjan, a theater director in Chicago, wanted pandemic company and got a rescue cat she named Aloo during the summer. The formerly feral cat is believed to be around 3, and seems to be very comfortable with a slow-paced, high-attention pandemic life.
“My working from home, I think he loves it,” she says. “I think he is just ready to settle down in life. If he were human, he’d probably sit on the couch with a PBR (beer) and watch TV all day.”
The pandemic hasn’t been positive for all pets, though, such as those with owners who are struggling financially.
Veterinarians and owners report some pets are being medicated for anxiety, and others are being put on diets because of too many treats and not enough exercise in parks that humans may be avoiding because of virus concerns.
Hilts says her cat, a rescue who joined their household in March 2019, always seemed to enjoy attention from strangers but now hides from visitors. Kursten Hedgis, a herbalist in Decatur, Georgia, says her dog Bitsy, also a rescue, misses the attention from other humans on their walks.
“He got really bummed out because no one would talk to him or pet him,” she says. “People would walk six feet around us. I think he took it personally.”
Bitsy, a yorkie, is 14 and has been with her six years after a life as a breeder in a puppy mill. He is blind in one eye and suffers periodic infections and incontinence. Trips to the veterinarian have been “really scary” because of the masks and reduced contacts.
However, Hedgis and other pet owners say they have become more than companions in recent months, that they provide valuable emotional support to their humans.
Humito seems to sense when she is feeling stressed and will take the initiative to cuddle into her lap, says Benavides, communications director for Republican Sen. Rob Portman of Ohio. “It’s a relationship built on mutual care and comfort,” Benavides says.
As humans begin to return to work and the vaccine rolls out, the next year likely will bring a test of those relationships and new habits. Says Ranjan of Aloo: “I hope he will take it in stride.”
Croney, the animal behavior professor with some two decades of experience, says she’s concerned about what will happen when she returns to work, and not only to her pets.
“I’m starting to worry a little bit for me,” she admits. “I’m becoming a little co-dependent of my animals.”
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