Killing Mosquitos With Recycled Tires

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Beginning in 2016, Dr. Gerardo Ulibarri, a researcher with the Laurentian University in Canada, began placing a special kind of mosquito trap around the town of Troncones, on the Pacific coast of Mexico’s Guerrero state.

These traps, called ovillantas, have proven successful in dramatically reducing the population of the Aedes aegypti mosquito and of the zika and chikungunya viruses that they can carry.

The ovillanta trap consists of a used car or truck tire, cut into two sections to  form an oval with a small opening into a dark interior. A plastic tap protrudes from the bottom section. Roughly half a litre of water with a strip of paper floating in it occupies the lower section. Mosquitos lay their eggs upon the water, which then stick to the paper. Every 2-3 days, the water is drained and the egg-laden paper destroyed and replaced.

The water is also replaced into the ovillanta. When mosquitos lay eggs, they emit pheromones that signal to other mosquitos that a given place is safe. The pheromone-rich water in the ovillanta, therefore, serves as an attractant to other mosquitos, drawing them into the trap. Although the pheromones work as a natural attractant, Dr. Ulibari continues to experiment with other, potentially more effective attractants.

Dr. Gustavo Velázquez Vélez, of the Troncones public health clinic, asserts that of the three main mosquito-borne illnesses found in Troncones – dengue, zika and chikungunya – the latter two have effectively vanished since the introduction of the ovillantas.

In 2015, Dr. Velázquez recorded 32 cases of chikungunya. In 2016, he recorded 37 cases of zika, with 3 cases affecting pregnant women. He recorded no cases of either disease from 2018 through May of 2019, the time of writing this article.

Dengue cases have dropped as well, although not in a statistically significant manner. Whereas zika and chikungunya are relative newcomers to the area, dengue has long been endemic. As such, it is present at lower rates, owing to more natural resistance within the local population and is harder to eradicate, due to occupying a wider geographical area.

Between 2015 and 2017, Velázquez recorded 5-9 cases of dengue per year. 2018 saw a notable drop, to zero recorded cases and in 2019, Velázquez saw only three cases of “probable dengue”, none of which was considered “serious”. Although tempting to draw the conclusion that dengue is on the retreat, the low number of overall cases make this a shaky proposition.

That said, the apparent local eradication of zika and chikungunya, along with the very low rate of dengue, is good news for Troncones, which is located between the popular tourist destination of Zihuatanejo and the quickly-growing surf destination of Saladita.

Dr. Ulibarri wishes to expand his ovillanta project throughout Mexico and beyond. This desire, unfortunately, faces some challenging obstacles. First, zika cases are down across Mexico as a whole (pdf, in Spanish, from Mexican government), which has led to a drop in public interest regarding sustained measures to control not only zika, but mosquito populations in general. While this is good news, a failure to sustain control measures raises the risk of relapse.

Second, the government has not provided Dr. Ulibari with the funding that he has sought, to expand the ovillanta project. As it stands now, small local projects like that in Troncones are funded by donations and kept alive through a very small number of dedicated volunteers. This works in a tight-knit and well-functioning community such as Troncones, but will need greater assistance to implement at scale.

Note: Post edited to clarify Dr. Gustavo Velázquez Vélez’s professional name as Dr. Velázquez, whereas he was previously referred to as Dr. Vélez.

Obama-Era Climate Science Panel Reconvenes

Rural towns that need to incorporate climate science into city plans often lack the budgets to do so. Image: Shutterstock

In September of 2015, President Obama chartered the creation of a committee dedicated to translating the findings of the periodic National Climate Assessment into to practical advice so that towns, counties, states and businesses could consider how to take appropriate actions. In August of 2017, President Trump allowed this committee’s charter to expire, thereby dissolving it.

Down But Not Out

The Federal Advisory Committee for the National Climate Assessment has been reborn as the Independent Advisory Committee (IAC), thanks to support from Columbia University’s Earth Institute and the administration of Governor Andrew Cuomo of New York.

Led by Dr. Richard Moss, the former chairman of the federal committee, the Independent Committee has reconvened and released the report that they had originally set out to write (with a briefer summary here).

A key finding of the report is that businesses, policymakers and other stakeholders need better support in understanding the science of climate change and incorporating findings into their plans.

Science in Action

To this end, the committee has launched the Science for Climate Action Network, or SCAN, an online platform to connect stakeholders at all levels with appropriate climate experts.

“Local governments and communities need help to use climate science to evaluate how mitigation and adaptation opportunities interact with their broader goals,” said Moss.”This new approach will make it easier to develop science-based pathways to address climate threats to local economic growth, infrastructure, and public health.”

The idea, says Moss, is to develop sets of means-tested practices through “careful comparative analysis of what is and isn’t working among groups working on a shared challenge.” In this way, knowledge about what does and doesn’t work for a given situation can be shared with others experiencing similar challenges.

Topics that SCAN is likely to address include incorporating climate risk into economic development planning and managing changing urban flood risk.

Getting the Message Out

Getting small towns and cities to engage in productive collaborations with climate scientists may prove challenging. While large and wealthy cities like New York and Los Angeles have budgets to support climate resilience research and have entire offices dedicated to that, small towns rarely do.

Another challenge will be that of raising awareness of SCAN. Few people read academic journals like the one that published the IAC’s report, particularly those that lack an office dedicated to incorporating climate knowledge into their development plans. Many of these smaller towns are important agricultural centers. Failures to improve climate resiliency here will have widespread knock-on effects.

SCAN certainly addresses a need in modern society. We certainly hope that it will prove effective.

Comunidade Yuba: An eighty year-old Japanese farming community thrives in Brazil.

Yuba residents harvest manioc before the storm. Photo: Jordan Kraft

In 1928, a Japanese farmer named Isamu Yuba emigrated to Brazil with his family as part of a large influx of agricultural workers. In need of hands on coffee plantations, Brazil had only recently opened its doors to Japanese immigration in 1908.

Yuba and his family settled near what is now the city of Aliança, where they proceeded to found a small community, in which Japanese traditions, artistic pursuit and agricultural work would form the foundations of a small but remarkably vibrant community. Eighty-one years later, the vision that is Yuba thrives as a Japanese pocket universe, nestled amongst the green folds of São Paulo State’s vast agricultural jigsaw puzzle.

Within its boundaries, one finds a unique mixture of modern Brazilian society and that of a recently past Japan. Kanji adorns signs and Japanese is spoken almost to exclusion. Food served in the communal hall consists of traditional Japanese staples, such as miso soup, tonkatsu, pickled vegetables, curry and plenty of rice. Homes are modelled on the farmhouses of rural Japan and shoes are always removed upon entry.

In the words of Tomohiro Takefumi, a recent visitor to Yuba: “It felt as though I had traveled back in time and arrived in Japan 50 years ago.”

Roasting coffee. Photo: Jordan Kraft.

Yuba is remarkable for its cultural tenacity. Over the 111 years of Japanese immigration to Brazil, Brazilians of Japanese descent have largely assimilated into modern Brazilian culture. According to Minoru Matsuura, the president of the Nikkei Association of Rio de Janeiro, “Japanese-Brazilians from the 3rd generation on don’t typically feel a strong Japanese identity.”

Yuba’s tenacity is all the more remarkable for the forces arrayed against migrant Japanese culture during WWII. After aligning itself with the Allies, Brazil arrested, relocated and deported thousands of families of Japanese descent, closed hundreds of Japanese schools and forbade both written and spoken Japanese. Only in 2013, did Brazil’s government officially apologize to its 1.5 million Japanese-Brazilians.

While Japanese-Brazilians were persecuted in Brazil, they were forgotten in Japan. Kai Kimura, a Japanese playwright who has long been interested in Japanese-Brazilian migration, found that all pre-1945 Brazilian immigration documents once held by the Japanese government had been incinerated during the war.

Far from being hidden and forgotten, Yuba currently enjoys a measure of notoriety, thanks to a surprising source. In 1961, the Japanese sculptor-ballerina couple of Hisao and Akiko Ohara moved to Yuba and build a theater and found a ballet troupe. The troupe has since performed throughout Brazil and has travelled to Japan dozens of times.

The ballet troupe has proven instrumental in introducing many Japanese to Yuba. Beginning with their first international performance, Japanese backpackers began to trickle through Yuba while exploring Brazil. Isamu Yazaki, a native of Yuba, recalls backpackers staying at Yuba for months at a time, volunteering with farm tasks and living with the Yubenses. Volunteers continue to visit, staying for anywhere from a few weeks to an entire year. The ballet troupe’s tours and these volunteers’ visits, he says, have facilitated a number of unions between Yubenses and Japanese. Isamu himself is one product of these transcontinental unions.

Today’s 60 or so Yubenses live and work together in a community modeled on the Japanese farming communities of the late nineteenth century. They grow okra, manioc, squash and mangos, among other crops. Yuba’s elders manage the income earned by farming. Much of it goes to the education of community members, repairs and provisioning of the farm and travel, the latter most often involving the ballet troupe.

Daily life consists of a combination of farm work and artistic pursuit. Days begin at sunrise, with a hearty breakfast featuring home-roasted coffee in a communal hall that is used for eating, meetings and a variety of other social activities.

Daily tasks fall into indoor and outdoor categories. Outdoors, people plant and harvest crops, clear weeds and feed the community’s chickens and pigs. Inside, coffee is roasted, fruit is cooked into preserves, crops are packaged for market and repairs to the community’s buildings are carried out in a cluttered shop full of sawdust and old machines. After dinner, people engage in their various artistic endeavors. At night, Yuba fills with the sounds of musical instruments, choir voices and ballet shoes tapping on a wooden floor. A kiln, in which hand-made pottery hardens, heats the jasmine-scented night air.

At once Brazilian, Japanese and something truly unique, Yuba shines within Brazil’s rich cultural tapestry.

A Bacteria Weaponized its Own Virus

Image: A Pf bacteriophage invades a mammalian cell. Credit: Dr.Paul L. Bollyky, et al.

For the first time ever, a bacteria has been found to weaponize its own virus to attack humans. A common bacteria called Pseudomonas aeruginosa produces a virus that makes the bacteria itself significantly more pathogenic. 

The virus in question is called a bacteriophage – or phage for short –  and belongs to a family of viruses that are thought to only be capable of infecting bacteria. P. aeruginosa, however, uses its phage to cause our bodies to react to a virus while ignoring the bacteria that produces it. In a Trojan horse strategy, this allows the bacteria to enter our cells and in the process, evades many common antibiotic therapies.

The World Health Organisation has labeled P. aeruginosa a “critical priority” pathogen; one that poses the greatest threat to human health. P. aeruginosa has been growing increasingly drug-resistant and accounts for a sizeable portion of infections involving ulcers, bedsores and burn wounds. 

Bacteria-eating cells in our bodies called phagocytes are trained to target and destroy bacteria by essentially eating them up. When a phagocyte encounters a virus, however, its reaction is to prevent the virus from getting inside the phagocyte, as doing so would lead to a viral infection. When phagocytes encounter P. aeruginosa’s bacteriophage, called Pf, they recognize its viral proteins and treat the entire bacterial cell as though it was a virus-infected human cell. The effect, says study lead author Dr. Paul Bollyky,  is like somebody pulling the fire alarm when they should have called the police. “If 20 fire engines pull up to the scene of the crime, it makes it easier for the thief to get away.”

These findings are significant, in that they change how we will have to view phages in the future. Although the idea that phages could be used to infect mammalian cells had been first proposed by Dr. Carl Merril in the 1970’s, it was met with derision and largely forgotten. The new study hammers home the fact that this process does, in fact, occur and must be taken seriously.

Fortunately, Dr. Bollyky’s team developed a vaccine against Pf, that successfully reduced the incidence of wounds infected with P. aeruginosa by half. Encouragingly, their vaccine may prove useful against other pathogenic bacteria as well, as several other species can also carry Pf and end to co-infect wounds colonized by P. aeruginosa.

The study was published in the journal Science on 29 March.

Go North, Young Mosquito.

Man’s deadliest enemy. Photo: Joel Sartore, National Geographic

After the floods, famines and forced migrations that global warming is predicted to bring about, the spread of mosquitoes may seem like adding insult to injury. Mosquitoes, however, remain our deadliest animal adversary, killing an estimated 100 million humans worldwide. 

But it gets worse. 

A recent study by an international team of scientists, published in Nature Microbiology, provides forecasts for how and where mosquitoes will spread under various climate change conditions. Long story short, none of these conditions involve a ‘no-spread’ option. 

The team, from the UK, the US and Belgium, focused on two key disease-spreading mosquito species: Aedes aegypti and Aedes albopictus. They first used historical data from over 3,000 locations in Europe and North America about the mosquitoes distributions to analyse how fast and into which habitats each species spread. 

They found that A. aegypti tends to spread over long distances, while A. albopictus‘s spread has been more localized. Within the U.S., A. aegypti spread north at a relatively constant rate, about 150 miles per year. A. albopictus spread most quickly between 1990 and 1995; its advance has since slowed to about 37 miles per year. In Europe, A. albopictus has spread faster, advancing about 62 miles per year increasing to 93 miles per year in the past five years.

The group’s models predict that A. aegypti will spread mostly within its current tropical range, but will also spread through warming temperate places in the U.S. and China, reaching as far north as Chicago and Shanghai, roughly by 2050. In central southern United States and Eastern Europe, which climate models predict will become more arid, A. aegypti is expected to decline.

In contrast, A. albopictus is predicted spread widely across Europe, reaching large areas of France and Germany over the next 30 years. The group also predicts that A. albopictus will establish toeholds the northern U.S. and the highland regions of South America and East Africa in that timeframe. 

These maps show the predicted global ranges of Aedes aegypti (above) and Aedes albopictus (below) in 2050 assuming a ‘medium’ climate scenario in which greenhouse gas emissions peak in 2080 and then begin to decline. The darker areas have the highest predicted prevalence of mosquitos. Image: Moritz Kraemer for Nature Microbiology; DOI: 10.1038/s41564-019-0376-y.

At the moment, human activity drives the greatest spread of mosquitoes, through simple things like leaving standing water untended and more complex things like rapidly rising ran populations. For the next 5-15 years, the group’s models predict human activity to remain the dominant factor in mosquito spread. After this, however, a warming climate looks likely to take over. 

With this new work, we can start to anticipate how the transmission of diseases like dengue and Zika might be influenced by a variety of environmental changes,” says Simon I. Hay, director of Geospatial Science at IHME and Professor of Health Metrics Sciences at the University of Washington. “Incorporating this information into future scenarios of risk can help policymakers predict health impacts and help guide strategies to limit the spread of these mosquito species, an essential step to reduce the disease burden.”

World’s Oldest Frozen Semen Sample Still as Viable as Ever

Sir Freddie. Photo credit: Walker family

Potential fathers who truly struggle with their decision to start a family can now delay that decision by decades.

Biologists in Sydney, Australia, recently thawed out sheep semen samples taken in 1968 and used it to impregnate Merino ewes. Out of 56 ewes inseminated, 34 were successfully impregnated, for a statistically equivalent pregnancy rate of 61% for the 50-year-old semen against 59% for sperm frozen for only 12 months. The pregnant ewes also experienced a live birth rate just as high as with the more recently frozen sperm.

“This demonstrates the clear viability of long-term frozen storage of semen,” says Associate Professor Simon de Graaf from the Sydney Institute of Agriculture and School of Life and Environmental Sciences at the University of Sydney.

Beyond the long-term storage finding, Dr. de Graaf and his colleague,  Dr Jessica Rickard say that the reproductive biology and genetic aspects of these as-yet unpublished findings are of most interest to them.

“We can now look at the genetic progress made by the wool industry over past 50 years of selective breeding. In that time, we’ve been trying to make better, more productive sheep,” says Professor de Graaf. “This gives us a resource to benchmark and compare.”

The original semen samples were donated in the 1960s from sires owned by the Walker family, who maintain a close and proud relationship with the animal breeding program at the University of Sydney.

So for those truly unable to commit to a family, your can now put your decision on ice for at least 50 years, although that level of procrastination may affect your family potential in other ways.

Stormtrooper (Spiders) in Colombia

Stormtropis musica. Photo credit: Carlos Perafan.

The stormtroopers have arrived.

Six new species of bald-legged spiders were discovered in Colombia, by Drs Carlos Perafan and Fernando Perez-Miles of the Universidad de la Republica, Uruguay and William Galvis of the Universidad Nacional de Colombia.

Four of the species did not fit into any known genus. The group created a new genus for them, naming it Stormtropis, after the clone soldiers of the Star Wars saga.

“The stormtroopers are the soldiers of the main ground force of the Galactic Empire. These soldiers are very similar to each other, with some capacity for camouflage, but with unskillful movements, like this new group of spiders,” explain the researchers.

“We wanted to make a play on words with the name of the known genus, Paratropis, and of course, we also wanted to pay tribute to one of the greatest sagas of all time.”

Bald-legged spiders are members of the small Paratropididae family and are fairly enigmatic in the world of science. In fact, their precise placement in the Tree of Life has been a matter of some debate. One of the unique characteristics of these spiders is their use of camouflage, which they accomplish by sticking pieces of the soil to their outer skin, or cuticle.

The group discovered one of the new species (Stormtropis musica, pictured) occupying the highest altitude habitat of any bald-legged spider, at around 3,400 m in the central Andes. However, the authors claim to have evidence of species living above 4,000 m, which they plan to publish in future papers.

They also discovered several cases of various bald-legged species burrowing into ravine walls or soil – the first example of such behavior to be reported. They suggest that this might be a secondary adaptation, allowing the spiders to use additional habitats.

Their results are reported in the journal ZooKeys.

Ready, Set, Sperm Race!

Sperm swimming under a microscope. Courtesy of Ovation Fertility.

An innovative new sperm sorting procedure offers the possibility of improved success rates for in vitro fertilization (IVF).

IVF is a costly procedure without guaranteed success. Women under 35 have only a 21.5 percent chance of a full-term live birth from a single round of IVF. At an average of $10,000-$15,000 per round in the U.S., improving the odds of IVF success is vital for the financial and emotional well-being of those who experience fertility problems.

Fundamentally, IVF relies upon placing healthy sperm in the vicinity of an egg to maximize the chances of a sperm penetrating the egg. To do this, sperm are sorted into those that can swim well (“swimmers”) and those that can’t (“non-swimmers”). Only swimmers are used to fertilize eggs.

The process of sorting sperm, however, can damage the DNA within them. This is because sperm are sorted through centrifugation (a sort of spinning), whose strong shearing forces can tear at the DNA strands within sperm nuclei.

A new technique under development by Dr. Afrouz Ataei of Florida Atlantic University offers a promising new means for sorting sperm that avoids the damaging centrifugation step.

Dr. Ataei has developed a microchip, in which sperm swim against a current. As Dr. Altaei explains, her chip exploits sperm’s natural tendency to turn towards an applied current and then swim against it.

Prior to running sperm through the chip, they are analysed for things like concentration, count and most importantly, a velocity parameter. The velocity parameter is a measure of the sample’s ability to swim against a flow and this determines the actual flow rate used during the process. In this way, each run through the system is tailored to its specific sperm sample.

The sperm samples that they have been able to collect, says Altaei, come close to 100% motility.

Still in early stages of development, Dr. Altaei and her colleagues are continuing to optimize their chip, hoping to increase the concentration of sperm collected before filing a patent on their design.

Using Wikipedia to Measure and Understand People’s Interest in Nature

Image credit: Jordan Kraft

Whether or not humans are growing increasingly distanced from nature is a perennially popular question in our technological age. Actually measuring changes in this supposed distance poses a thorny challenge.

Past researchers have measured the proportion of “nature-related words” in song lyrics, without asking whether this is a good proxy for a society’s attitudes towards nature to begin with. Others have compared the ability of 4-7 year-olds to identify plant and animal species versus various Pokemon (seriously, why?).

Taking a big data approach, an international team of researchers from the Universities of Oxford, Birmingham and Ben-Gurion recently published a study whose encouraging results come without many of the subjectivity pitfalls of past efforts.

Using 2.33 billion Wikipedia pageview records over the span of 3 years and across 245 languages, the team saw that what happens in the natural world affects what people search for online.

Specifically, they saw that people’s online interest in plants and animals changed with the seasons. For instance, searches for flowering plants showed much stronger seasonal trends than those for coniferous trees, which are largely evergreen.

This seasonality is directly relevant to conservationists. Predictable spikes in interest provide clear opportunities to maximize the impact of environmental fundraising campaigns. They also provide a good starting point to understand what drives such interest. Put together, these data could help conservationists understand both when and how to best target their campaigns.

Two trends in the data help to understand drivers of seasonal interest. First, they noted that seasonality corresponded with the languages used in searches. Higher latitudes experience greater seasonal changes. The languages spoken there, such as Norwegian and Finnish turn up more seasonal searches for plant and animal species, than did searches in languages from tropical latitudes without great seasonal changes, such as Thai.

Second, they noticed that seasonal patterns often corresponded to cultural events, such as annual holidays. Wild turkey during Thanksgiving in the United States, for instance, or sharks during Shark Week.

In the words of lead author and University of Oxford PhD student John Mittermeier: “To see that online activity often correlates strongly with natural phenomena suggests that people are paying attention to the world around them, and from a conservation perspective that is really exciting.”

It’s also exciting to see how people use their “artificial” world to interact with the “natural” one.

When Environmental Regulations Backfire

Itaipú Dam. Image credit: Escuela de Organización Industrial

Hydropower – the energy generated from flowing water – is renewable and emits relatively low amounts of carbon dioxide. Many see the expansion of hydropower as a way to offset fossil fuel-derived energy. In keeping with its green nature, environmental regulations exist to minimise the ecological impact of hydropower plants and to guide their construction and operation.

Counterintuitively, these same regulations may be responsible for an increase in carbon emissions. The regulations meant to keep a hydropower plant’s environmental impact small, also make these plants costly to build, run and maintain. The result is that utility companies that might otherwise invest in hydroelectricity instead choose to pursue environmentally costlier but economically cheaper fossil fuels.

Such are the results of a study by Dr. Edson Severini of Carnegie Mellon University, published on 10 January in PLOS One. In this study, Dr. Severini calculated that each megawatt of fossil fuel-based energy that was installed due to ecosystem preservation regulations that limited hydropower development led to an increase in annual carbon dioxide emissions of roughly 1,400 tons. This is roughly the amount of energy that will get an average-sized car between San Francisco and New York City and the amount of CO2 emitted by 200 individual Americans per year. 

Hydropower itself is cheap, compared to energy generated from fossil fuels. The Wisconsin Valley Improvement Company, a natural resources management company, estimates that In the U.S., “hydropower is produced for an average of 0.85 cents per kilowatt-hour (kwh). This is about 50% the cost of nuclear, 40% the cost of fossil fuel, and 25% the cost of using natural gas.”

International Rivers, an environmental NGO, points out that the cost of building dams almost always exceeds initial estimates, often by up to 30% and can take years to build. As a case study, they point to the Itaipú Dam, which cost USD$20 billion and took 18 years to complete. While the costs of energy production may compensate for such high building costs in the long run, such high building costs may not be recovered for many years, which surely affects decisions over which type of power generation to pursue. The further cost of complying with strict environmental regulations can play a decisive role in these decisions.

In his paper, Dr. Severini suggests that future regulations should strike a balance between local environmental concerns and the more global concern of climate change. Current regulations backfired, argues Dr. Severini, because environmental regulations meant to thwart one form of energy didn’t account for what would replace it.

One place to start might be laws requiring the federal government to consider the climate consequences of building any type of power plant. As of now, no such law exists.