Earth

Share the code and data behind the research please. It's easy, but it will have a major positive impact on progress and trust in science. That is the clear message from a new paper in PLOS Biology. An international team of ecologists found that currently, only about a quarter of the scientific papers in their field publicly shares computer code for analyses. "To make the science of ecology more transparent and reproducible, sharing is urgently needed."

Open access, open source, open science. Although there is much talk about these important 'open' topics, the practice of sharing scientific data and especially accompanying code is lagging behind. And ecology is no exception.

"We urgently need to improve the reproducibility of ecological research," explains lead author Antica Culina from the Netherlands Institute of Ecology (NIOO-KNAW). "The code is an essential part of the research process. If this code is shared with others, they can fully understand and evaluate the results. They can also use the code for their own work, accelerating scientific discovery."

Start counting

Both the underlying data and the code to analyse it are needed to check and reuse scientific results. This might be particularly important in ecology, because of the sophisticated models used.

How many scientific journals encourage data and code sharing? And how many researchers actually share this? Together with fellow ecologists from Bielefeld University, Oxford University and Exeter University, Culina started counting.

Numbers talk

The numbers talk straight language. Culina: "Our results, combined with previous findings, indicate that less than 20% of ecological research is computationally reproducible." From a random sample of hundreds of scientific articles on ecology, 79% had data available but only 27% was accompanied by code. Put together, this results in only about 20% of articles that is 'computationally reproducible'. The actual numbers are probably even lower, as the team only looked into articles from journals that at least encourage code sharing. But it doesn't end there.

A large part of the remaining literature with code and data available did not use free software (26%), did not report the software version (46%), and based on previous work by Roche and colleagues it is likely that many of the datasets (56%) are incomplete.

"On the positive side," adds Culina, "more and more journals are adopting code-sharing policies, most of the published code is written in software that can be used by anyone who wants it, and ever more code is published in trusted 'repositories'."

To be open

The researchers used:

a random sample of 346 articles about nonmolecular subjects from 14 ecological journals,

articles published between 2015 and 2019 under mandatory or encouraged code-sharing policies. (This means that the percentages mentioned are probably overestimating the truly reproducible literature.)

They found out that:

more and more ecological journals have mandatory or encouraged code-sharing policies, up from 15% in 2015 to 75% in 2020,

still, code-sharing policies are not adhered to by most people.

Address it

The international research team hopes that these results will encourage journals, institutions, funding agencies and researchers to address this "alarming situation". They also share helpful hints of how to do this. As Culina puts it: "We specifically call for a drastic increase in code availability, and we reach out to journals, authors and reviewers to contribute to this much needed change." And no worries: "It is actually quite simple to share your code. Science thrives on collaboration and openness - let's help ecology to thrive."

The coronavirus pandemic brought unprecedented uncertainty and stress. But even amid the turmoil and the new pressures of work-from-home and home-schooling, millions of people were able to keep calm and carry on with the demands of the moment.

Research forthcoming in the Journal of Applied Psychology shows that the human sense of normalcy is capable of bouncing back a lot faster than we might think.

"Our psychological immune system is so effective that even though we have an ongoing, persisting stressor, we start to fix ourselves almost immediately," says management professor Trevor Foulk at the University of Maryland's Robert H. Smith School of Business, who authored the research with colleagues from the University of Southern California, Singapore Management University and the University of Florida.

"When a big stressor happens, it knocks us out of our pattern. We feel like we don't have control and we're just not like our normal selves," says Foulk. "We have always tended to think that we'll only get our sense of normalcy back when the stressor goes away." Not true, according to Foulk's latest research.

The study, "Getting Back to the 'New Normal': Autonomy Restoration During a Global Pandemic," shows that psychological recovery can take place even while a person is still in the throes of a stressful experience. That's significant; previous research has suggested that recovery processes start only after stressors abate and can take months or even years to unfold.

In the latest study, researchers surveyed 122 employees several times each day for two weeks to explore how they experienced the pandemic. The study began on March 16, 2020, just as stay-at-home orders and school closures went into effect across U.S. cities and states. It was just days after the World Health Organization's March 11 declaration that COVID-19 had reached pandemic status. The timing meant that researchers had a unique opportunity to study the very early days of the crisis.

The researchers focused on two manifestations of normalcy - specifically powerlessness and authenticity. They found that on the first day of the study, just as the crisis was beginning, employees initially felt very powerless and inauthentic.

"But, over the course of even just those two weeks, normalcy started to return," he says. "People felt less powerless and more authentic - even while their subjective stress levels were rising."

It's an important finding, as it suggests that humans can establish a new normal even while feeling stressed and worried.

Foulk says this shows employees were adjusting to their new situations and the disruptions associated with the crisis and establishing a new way of feeling normal. "The pace at which people felt normal again is remarkable, and highlights how resilient we can be in the face of unprecedented challenges."

The effect was more pronounced for more neurotic individuals - people who tend to be more nervous, anxious, depressed, self-conscious and vulnerable. Those employees had a more extreme initial reaction to the stress, but then recovered at a faster rate. The researchers say this is likely because employees high in neuroticism are better psychologically equipped to navigate stress so they can bounce back from it quicker.

Overall, Foulk says, all employees start to feel normal much faster than most would expect.

"Contrary to a lot of the doom and gloom we're hearing, our work offers a little bit of a ray of hope - that our psychological immune system starts working a lot faster than we think, and that we can start to feel 'normal' even while all of this is going on."

A large-scale trial has found a treatment with pimavanserin substantially reduced psychotic symptoms and reduced risk of relapse of those symptoms compared to placebo in people with dementia, a condition for which no treatments are currently licensed.

New data presented at the Alzheimer's Association International Conference indicates that pimavanserin leads to a robust reduction in the severity of psychosis symptoms during the 12 week open-label phase of the study, regardless of the underlying dementia subtype or the severity of participants' dementia.

The international phase three relapse-prevention trial was conducted in collaboration with the University of Exeter, working with Acadia Pharmaceuticals. The trial enrolled 392 participants who were experiencing hallucinations and delusions as a result of their dementia.

Up to half of the 45 million people worldwide who are living with Alzheimer's disease will experience psychotic episodes, a figure that is even higher in some other forms of dementia. Psychosis is linked to a faster deterioration in dementia, and is disturbing for the individual and carers.

Currently there is no approved safe and effective treatment for these distressing symptoms associated with dementia-related psychosis. In people with dementia, widely-used antipsychotics lead to sedation, falls, and can double the speed at which brain function deteriorates.

Pimavanserin works differently, by blocking a very specific nerve receptor (5HT2A) in the brain. Now, it has been found to effectively reduce symptoms of psychosis in people with Alzheimer's disease and other dementias, without evidence of some of the common side effects observed with other antipsychotics.

Clive Ballard, Professor of Age-Related Diseases at the University of Exeter Medical School, who co-authored the research presented at AAIC, said: "Psychosis is a common and extremely disturbing symptom which has a severe impact on the lives of people affected by dementia. We urgently need treatments that work, and I'm excited by the potential of pimavanserin to make a real difference."

Lithium, the silvery metal that powers smart phones and helps treat bipolar disorders, could also play a significant role in the worldwide effort to harvest on Earth the safe, clean and virtually limitless fusion energy (link is external) that powers the sun and stars. First results of the extensively upgraded Lithium Tokamak Experiment-Beta (LTX-β) at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL), demonstrate that the major enhancements operate as designed and improve the performance of the hot, charged plasma that will fuel future fusion reactors.

More fusion-relevant

The three-year upgrade turned what is now the LTX-β into a hotter, denser and more fusion-relevant device that will test how well coating all plasma-facing walls with liquid lithium can improve the confinement and increase the temperature of the plasma. "We achieved many of our initial engineering goals," said physicist Drew Elliott of Oak Ridge National Laboratory, a major collaborator of the LTX-β. Elliott, on long-term assignment to PPPL, served as lead author of the first results (link is external) paper reported in IEEE Transactions in Plasma Science.

Fusion reactions combine light elements in the form of plasma -- the state of matter composed of free electrons and atomic nuclei that makes up 99% of the visible universe -- to release enormous amounts of energy. Physicists around the world are seeking to duplicate and control fusion reactions to create boundless safe, carbon-free power to generate electricity.

Key features of the LTX-β, a smaller version of the widely used doughnut-shaped magnetic tokamak (link is external) facilities that house fusion reactions, include these factors: A powerful neutral beam injector to heat and fuel the plasma; a nearly doubled magnetic field compared with the previous device; and a twin evaporation system to fully coat liquid lithium on all the plasma-facing surfaces.

Matched predictions

Operation of the beam matched well with predictions of the fraction of power that it would deposit into the plasma, rather than simply shining through it. "We're looking to increase the power deposition toward 100% so that all the power we inject goes into the plasma," said Elliott, who led the optimization of the neutral beam, which is based on technology pioneered at ORNL in the 1970s. "That will be a big scientific push, in future campaigns."

The substantial enhancements aim to test whether the LTX-β can improve plasma performance beyond the notable achievements of its predecessor. These include the demonstration of temperatures that remain constant, or flat, all the way from the hot core of the plasma to the normally cool outer edge.

Such gradient-free temperature profiles, the first ever seen in a magnetic fusion facility in the previous device, stem from the ability of lithium to hold onto stray particles that leak from the core of the plasma and keep them from recycling back and cooling the edge and core of the plasma. Sustainment of the hot edge expands the volume of plasma available for fusion and the production of flat temperature prevents instabilities that reduce plasma confinement from developing.

Goals of the upgrade

"The goals of the upgrade are to determine whether very low recycling lithium walls can improve plasma confinement in a tokamak with neutral beam heating," said Dick Majeski, principal investigator for LTX-β. "If LTX-β is successful, we can move on to experiments on liquid lithium in the National Spherical Torus Experiment-Upgrade [NSTX-U]," the flagship fusion experiment at PPPL.

The initial run of the LTX-β demonstrated improvements that included the following:

Increased fueling and density of the plasma, major goals of the neutral beam injector;

Increased deposition of liquid lithium over more than 90% of the inner walls of the LTX-β;

Longer plasma discharges, or pulses, enabled by the strengthened magnetic field; and

Higher plasma current -- a critical element that causes the magnetic field to spiral, which is necessary to confine the plasma.

Also installed in the upgrade are new plasma diagnostics that will further characterize the facility's expanded operating regime. And still to be commissioned are advanced diagnostics that will measure the precise profile of several plasma parameters.

"The addition of the neutral beam increases the input power to the plasma by an order of magnitude and has the potential of creating a fusion-relevant plasma regime with enhanced performance," said Phil Efthimion, head of PPPL's Plasma Science & Technology Department that includes the LTX-β. "Dick Majeski and the entire LTX-β team should be commended for completing this aggressive upgrade on budget and schedule.

Experts across the U.S.

The upgrade pulled from experts across the United States, including collaboration from PPPL, ORNL, Princeton University, the University of California, Los Angeles (UCLA), and the University of Tennessee, Knoxville, and provides a significant tool for fusion research.

"ORNL and PPPL have been partners in fusion science and technology for many years, and this continues that strong union," said Mickey Wade, director of ORNL's Fusion Energy Division. "LTX-β will allow the fusion community to dig deeper into the promise of lithium and what it could unlock in enabling practical fusion energy."

Majeski has big plans ahead. "In the future, we'd like to increase the pulse length of the neutral beam to provide a longer period of heating and fueling for the plasma," he said. "The beam adds a lot of flexibility to the experiment, and we want to take advantage of the new capabilities."

Agricultural production is highly sensitive to weather and climate, which affect when farmers and land managers plant seeds or harvest crops. These conditions also factor into decision-making, when people decide to make capital investments or plant trees in an agroforestry system.

A new report from the U.S. Department of Agriculture focuses on how agricultural systems are impacted by climate change and offers a list of 20 indicators that provide a broad look at what's happening across the country.

The report, "Climate Indicators for Agriculture," is co-authored by Colorado State University's Peter Backlund, associate director of the School of Global Environmental Sustainability.

Backlund said the research team started with the scientific fact that climate change is underway.

"We looked at the U.S. agricultural system and examined the climate stresses," he said. "This report outlines data that farmers and land managers can use to understand how climate change is affecting their operations, and, hopefully, guide the development of effective adaptation."

In the report, the authors outline how the changes taking place in agriculture affect the system that many people make their livelihoods from.

"We want to help farmers, ranchers and land managers adapt better under climate change, which requires understanding what is actually happening on the ground. These indicators offer ways to measure the impacts of change," said Backlund.

20 climate indicators, based on robust data

The climate indicators described in the report are arranged in five categories, including physical (extreme precipitation and nighttime air temperature), crop and livestock (animal heat stress and leaf wetness duration), biological (insect infestation in crops, crop pathogens), phenological (timing of budbreak in fruit trees, disease vectors in livestock) and socioeconomic (crop insurance payments, heat-related mortality of agricultural workers).

Backlund said the research team chose these indicators based on the strength of their connection to climate change and availability of long-term data, which is needed to identify how impacts are changing over time and whether adaptive actions are having the desired effect.

"There had to be a measurement of a variable strongly coupled with climate," he said. "As we go forward, we will better understand the impact of climate change by using these indicators."

Researchers opted to include nighttime air temperatures as opposed to general temperature because nighttime temperatures have a big effect on the way plants develop.

Some of the indicators have national data, while others are more regional. Heat stress on livestock, a huge issue for feedlot operators, will be of interest to farmers and ranchers in states including Colorado.

"Heat interferes with the rate of reproduction and rate of weight gain," Backlund said. "This presses on the whole operation; it's not just that a few more animals will die from getting too hot."

The crop insurance payment indicator offers insight on the repercussions of climate events.

"You can see if you have a big climate event, like drought, one region will be much more affected than another," he said. "If farmers have good irrigation, they'll be much more capable in dealing with periods of low rainfall."

Backlund said the indicator covering weed range and intensity was also notable. As carbon dioxide concentrations increase, researchers are seeing extreme northern migrations and expanded ranges for weeds.

Per- and polyfluoroalkyl substances (PFAS), found in many household products and food packages, have raised concerns because of their persistence and possible toxicity to people and wildlife. Because the compounds don't break down naturally, they have become environmental contaminants. Now, researchers reporting in ACS' Environmental Science & Technology have studied the transport of 29 PFAS into and out of the Arctic Ocean, detecting a newer compound for the first time in Arctic seawater.

After studies indicated that two PFAS -- PFOA and PFOS -- can cause cancer, a compromised immune response and other health problems in lab animals, the two compounds were voluntarily phased out by industry. However, these legacy compounds are still widely detected in the environment. Intended as a safer replacement for PFOA, HFPO-DA (sold under the trade name GenX) is now thought to pose similar health and persistence concerns. Hanna Joerss and colleagues wanted to investigate the long-range, oceanic transport of legacy and replacement PFAS to the Arctic Ocean -- a remote body of water connected to the Atlantic Ocean by the Fram Strait, which is located between Svalbard and Greenland.

Aboard an icebreaker research ship, the team collected water samples along two Fram Strait currents entering and exiting the Arctic Ocean and along a path from Europe's North Sea to the Arctic Ocean. Using mass spectrometry, the researchers detected 11 PFAS in the ocean water, including PFOA, HFPO-DA and other long- and short-chain PFAS. This was the first time that HFPO-DA had been detected in seawater from a remote region, indicating that the compound can be transported long distances. Higher levels of PFAS were detected in the water exiting the Arctic Ocean compared with the water entering the Arctic from the North Atlantic. The PFAS composition in the outgoing water suggested that more of these compounds arose from atmospheric sources than from ocean circulation.

Mussels secrete sticky plaques that help them attach to wet surfaces, such as rocks on the beach. These adhesive structures are rich in iron, which is thought to help make the attachments strong yet flexible. Now, researchers reporting in Environmental Science & Technology have shown that mussels form weaker attachments in iron-deficient seawater, revealing a possible consequence of altered iron bioavailability in oceans.

As oceans become more acidic in a changing climate, iron dissolves and is less bioavailable to filter feeders, such as mussels, that strain iron particles from seawater. In mussels, iron helps cross-link proteins in the sticky plaques that attach to surfaces and adds mechanical toughness to the hair-like threads that link the plaque to the mollusk's inner tissues. Jonathan Wilker and colleagues at Purdue University wondered how mussels' ability to adhere to surfaces would be affected by changing iron levels in seawater.

To find out, the researchers cultured mussels in artificial seawater containing lower, normal and higher iron levels. The researchers grew the mussels in each water condition for three days, during which the creatures attached to aluminum plates. Then, the researchers cut off the threads near the shell and pulled upward on them, measuring the force needed to remove the plaque from the plate. As the concentration of iron in the water increased, so did the plaque's stickiness, except for the highest iron level, at which adhesion slightly decreased. The team also observed that the plaques became smaller and darker as the iron concentration increased, and the porous microstructure of the plaques became more pronounced. This study is the first to examine how changing iron levels affect the performance of a biological material in a whole animal, the researchers say.

The authors acknowledge funding from the Office of Naval Research, the National Science Foundation and the Purdue Research Foundation.

Scientists have found that a physical property called 'quantum negativity' can be used to take more precise measurements of everything from molecular distances to gravitational waves.

The researchers, from the University of Cambridge, Harvard and MIT, have shown that quantum particles can carry an unlimited amount of information about things they have interacted with. The results, reported in the journal Nature Communications, could enable far more precise measurements and power new technologies, such as super-precise microscopes and quantum computers.

Metrology is the science of estimations and measurements. If you weighed yourself this morning, you've done metrology. In the same way as quantum computing is expected to revolutionise the way complicated calculations are done, quantum metrology, using the strange behaviour of subatomic particles, may revolutionise the way we measure things.

We are used to dealing with probabilities that range from 0% (never happens) to 100% (always happens). To explain results from the quantum world however, the concept of probability needs to be expanded to include a so-called quasi-probability, which can be negative. This quasi-probability allows quantum concepts such as Einstein's 'spooky action at a distance' and wave-particle duality to be explained in an intuitive mathematical language. For example, the probability of an atom being at a certain position and travelling with a specific speed might be a negative number, such as -5%.

An experiment whose explanation requires negative probabilities is said to possess 'quantum negativity.' The scientists have now shown that this quantum negativity can help take more precise measurements.

All metrology needs probes, which can be simple scales or thermometers. In state-of-the-art metrology however, the probes are quantum particles, which can be controlled at the sub-atomic level. These quantum particles are made to interact with the thing being measured. Then the particles are analysed by a detection device.

In theory, the greater number of probing particles there are, the more information will be available to the detection device. But in practice, there is a cap on the rate at which detection devices can analyse particles. The same is true in everyday life: putting on sunglasses can filter out excess light and improve vision. But there is a limit to how much filtering can improve our vision -- having sunglasses which are too dark is detrimental.

"We've adapted tools from standard information theory to quasi-probabilities and shown that filtering quantum particles can condense the information of a million particles into one," said lead author Dr David Arvidsson-Shukur from Cambridge's Cavendish Laboratory and Sarah Woodhead Fellow at Girton College. "That means that detection devices can operate at their ideal influx rate while receiving information corresponding to much higher rates. This is forbidden according to normal probability theory, but quantum negativity makes it possible."

An experimental group at the University of Toronto has already started building technology to use these new theoretical results. Their goal is to create a quantum device that uses single-photon laser light to provide incredibly precise measurements of optical components. Such measurements are crucial for creating advanced new technologies, such as photonic quantum computers.

"Our discovery opens up exciting new ways to use fundamental quantum phenomena in real-world applications," said Arvidsson-Shukur.

Quantum metrology can improve measurements of things including distances, angles, temperatures and magnetic fields. These more precise measurements can lead to better and faster technologies, but also better resources to probe fundamental physics and improve our understanding of the universe. For example, many technologies rely on the precise alignment of components or the ability to sense small changes in electric or magnetic fields. Higher precision in aligning mirrors can allow for more precise microscopes or telescopes, and better ways of measuring the earth's magnetic field can lead to better navigation tools.

Quantum metrology is currently used to enhance the precision of gravitational wave detection in the Nobel Prize-winning LIGO Hanford Observatory. But for the majority of applications, quantum metrology has been overly expensive and unachievable with current technology. The newly-published results offer a cheaper way of doing quantum metrology.

"Scientists often say that 'there is no such thing as a free lunch', meaning that you cannot gain anything if you are unwilling to pay the computational price," said co-author Aleksander Lasek, a PhD candidate at the Cavendish Laboratory. "However, in quantum metrology this price can be made arbitrarily low. That's highly counterintuitive, and truly amazing!"

Dr Nicole Yunger Halpern, co-author and ITAMP Postdoctoral Fellow at Harvard University, said: "Everyday multiplication commutes: Six times seven equals seven times six. Quantum theory involves multiplication that doesn't commute. The lack of commutation lets us improve metrology using quantum physics.

"Quantum physics enhances metrology, computation, cryptography, and more; but proving rigorously that it does is difficult. We showed that quantum physics enables us to extract more information from experiments than we could with only classical physics. The key to the proof is a quantum version of probabilities -- mathematical objects that resemble probabilities but can assume negative and non-real values."

Grassroots knowledge from Indigenous people can help to map and monitor ecological changes and improve scientific studies, according to Rutgers-led research.

The study, published in the Journal of Applied Ecology, shows the importance of Indigenous and local knowledge for monitoring ecosystem changes and managing ecosystems. The team collected more than 300 indicators developed by Indigenous people to monitor ecosystem change, and most revealed negative trends, such as increased invasive species or changes in the health of wild animals. Such local knowledge influences decisions about where and how to hunt, benefits ecosystem management and is important for scientific monitoring at a global scale.

"Scientists and Indigenous communities working together are needed to understand our rapidly changing world," said lead author Pamela McElwee, an associate professor in the Department of Human Ecology in the School of Environmental and Biological Sciences at Rutgers University-New Brunswick. "Many Indigenous peoples have unique abilities to notice ecosystems altering before their eyes by using local indicators, like the color of fat in hunted prey or changes in types of species found together. Scientists wouldn't be able to perform these kinds of observations over the long run for many reasons, including costs and the remoteness of some areas. So Indigenous knowledge is absolutely essential for understanding the cumulative impacts of biodiversity loss and ecosystem degradation."

Indigenous and local knowledge is the practical information that people use to manage resources and pass on between generations. Such knowledge benefits conservation initiatives and economies that depend on natural resources in vast areas of the world.

The study follows the Global Assessment Report on Biodiversity and Ecosystem Services released last year by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. That report was the first global ecological assessment to use Indigenous and local knowledge as a source of evidence.

The new study, by researchers at many institutions who were part of the global assessment, provides background on how the report tapped into Indigenous knowledge systems and lessons learned. Working with these local sources of information in ecological research and in management requires a deliberate approach from the start, additional resources and engagement with stakeholders reflecting diverse worldviews, McElwee said.

"Partnering with Indigenous peoples can help scientists and researchers understand how natural and cultural systems affect each other, identify trends through diverse indicators and improve sustainable development goals and policies for all," she said.

A luxury automobile is not really a place to look for something like sisal, hemp or wood. Yet auto makers have been using natural fibres for decades.

Some high-end sedans and coupes use these in composite materials for interior door panels; engine, interior and noise insulation; and internal engine covers among other uses.

Unlike steels or aluminium, natural fibre composites do not rust or corrode. They can also be durable and easily molded.

The biggest benefits fibre reinforced polymer composites bring to cars are the light weight, good crash properties, and noise and vibration reducing characteristics.

But making more parts of a vehicle from renewable sources is a challenge. Natural fibre polymer composites can crack, break and bend. The reasons for this include too low tensile, flexural and impact strength in the composite material.

Researchers from the University of Johannesburg have now demonstrated that plantain, a starchy type of banana, is a promising source for an emerging type of composite materials for the automotive industry. The natural plantain fibres are combined with carbon nanotubes and epoxy resin to form a natural fibre-reinforced polymer hybrid nanocomposite material.

Plantain is a year-round staple food crop in tropical regions of Africa, Asia and South America. Many types of plantain are eaten cooked.

The researchers moulded a composite material from epoxy resin, treated plantain fibers and carbon nanotubes. The optimum amount of nanotubes was 1% by weight of the plantain-epoxy resin combined.

The resulting plantain nanocomposite was much stronger and stiffer than epoxy resin on its own.

The composite had 31% more tensile and 34% more flexural strength than the epoxy resin alone. The nanocomposite also had 52% higher tensile modulus and 29% higher flexural modulus than the epoxy resin alone.

"The hybridization of plantain with multi-walled carbon nanotubes increases the mechanical and thermal strength of the composite. These increases make the hybrid composite a competitive and alternative material for certain car parts," says Prof Tien-Chien Jen.

Prof Jen is the lead researcher in the study and the Head of the Department of Mechanical Engineering Science at the University of Johannesburg.

Natural fibres vs metals

Producing car parts from renewable sources have several benefits, says Dr Patrick Ehi Imoisili. Dr Imoisili is a postdoctoral researcher in the Department of Mechanical Engineering Science at the University of Johannesburg.

"There is a trend of using natural fibre in vehicles. The reason is that natural fibres composites are renewable, low cost and low density. They have high specific strength and stiffness. The manufacturing processes are relatively safe," says Imoisili.

"Using car parts made from these composites, can reduce the mass of a vehicle. That can result in better fuel-efficiency and safety. These components will not rust or corrode like metals. Also, they can be stiff, durable and easily molded," he adds.

However, some natural fibre reinforced polymer composites currently have disadvantages such as water absorption, low impact strength and low heat resistance. Car owners can notice effects such as cracking, bending or warping of a car part, says Imoisili.

Standardised tests

The researchers subjected the plantain nanocomposite to a series of standardised industrial tests. These included ASTM Test Methods D638 and D790; impact testing according to the ASTM A-370 standard; and ASTM D-2240.

The tests showed that a composite with 1% nanotubes had the best strength and stiffness, compared to epoxy resin alone.

The plantain nanocomposite also showed marked improvement in micro hardness, impact strength and thermal conductivity compared to epoxy resin alone.

Moulding a nanocomposite from natural fibres

The researchers compression-moulded a 'stress test object'. They used 1 part inedible plantain fibres, 4 parts epoxy resin and multi-walled carbon nanotubes. The epoxy resin and nanotubes came from commercial suppliers. The epoxy was similar to resins that auto manufacturers use in certain car parts.

The plantain fibres came from the 'trunks' or pseudo-stems, of plantain plants in the south-western region of Nigeria. The pseudo-stems consist of tightly-overlapping leaves.

The researchers treated the plantain fibers with several processes. The first process is an ancient method to separate plant fibres from stems, called water-retting.

In the second process, the fibres were soaked in a 3% caustic soda solution for 4 hours. After drying, the fibres were treated with high-frequency microwave radiation of 2.45GHz at 550W for 2 minutes.

The caustic soda and microwave treatments improved the bonding between the plantain fibers and the epoxy resin in the nanocomposite.

Next, the researchers dispersed the nanotubes in ethanol to prevent 'bunching' of the tubes in the composite. After that, the plantain fibres, nanotubes and epoxy resin were combined inside a mold. The mold was then compressed with a load for 24 hours at room temperature.

Food crop vs industrial raw material

Plantain is grown in tropical regions worldwide. This includes Mexico, Florida and Texas in North America; Brazil, Honduras, Guatemala in South and Central America; India, China, and Southeast Asia.

In West and Central Africa, farmers grow plantain in Cameroon, Ghana, Uganda, Rwanda, Nigeria, Cote d'Ivoire and Benin.

Using biomass from major staple food crops can create problems in food security for people with low incomes. In addition, the automobile industry will need access to reliable sources of natural fibres to increase use of natural fibre composites.

In the case of plantains, potential tensions between food security and industrial uses for composite materials are low. This is because plantain farmers discard the pseudo-stems as agro-waste after harvest.

Curtin research has recorded the first known appearance of Pseudoanthidium (Immanthidium) repetitum, the African carder bee, in Western Australia and has highlighted the need to closely monitor the impacts of such introduced species on the ecosystem.

Published in Pacific Conservation Biology, the research documented the first WA sightings of the bee, which was first recorded in Australia in 2000 in Queensland, before rapidly spreading down the east coast and by 2015 becoming a common inhabitant of urban gardens in Victoria.

Author, Curtin PhD candidate and Forrest Foundation Scholar Miss Kit Prendergast, from Curtin's School of Molecular and Life Sciences, said the first occurrences of the species in WA, represented a major expansion of the distribution of the species.

"So far there are three confirmed and one unconfirmed site where this species has been seen, all in residential areas of WA's Mandurah region," Miss Prendergast said.

"Female specimens were collected from a garden in the Mandurah suburb of Halls Head, where it was seen to be abundant and with other bees, both native and the introduced European honeybee, foraging alongside it.

"Given the sheer distance across the continent, the bee may well have made its way to WA with human-assistance and the fact it has been recorded only in Mandurah, a major port, suggests it may have arrived by boat."

Miss Prendergast said the bee's presence in WA remained rare and localised but given the known negative impacts of introduced species on native fauna and flora, especially in Australia, the impact of such introduced species needed to be carefully monitored.

"While the bee could currently be considered benign, introduced species can be 'sleeper' species, and go through a lag phase, following which they become an environmental or economic pest, meaning ongoing monitoring is required," Miss Prendergast said.

"African carder bee nests are easily distinguishable from those of native bees and are made from hair-like plant fibres that females scrape from leaves and stems and roll into balls, with the nest resembling a mass of cotton wool.

"Unlike native Australian bees, which all are solitary nesters, the African carder bee nests communally, where masses of brood cells from multiple females are found in the one place."

Possible sightings of the small black and white-striped bee or its nests, often found in electrical meter boxes, can be reported to Miss Prendergast's Facebook page Bees in the burbs.

CORVALLIS, Ore. - Plucky, beautiful and declining in numbers at about a 2% annual rate, the rufous hummingbird makes its long annual migration in different timing and route patterns based the birds' age and sex, new research by Oregon State University shows.

The findings, published in the journal Avian Conservation & Ecology, are important because the more that is known about how rufous hummingbirds migrate, the more that can be done to ensure birds of different ages and sexes have the resources they need each year on their journey up and down the western part of North America.

"Different age-sex categories of rufous hummingbirds use alternative routes and differ in migration cycles and distributions," said the study's corresponding author, Jose?e Rousseau, a Ph.D. candidate in the OSU College of Forestry. "Our results seem to indicate that the age-sex categories could be affected in different ways by things like habitat loss and climate during migration. If we keep that in mind, we can make conservation efforts that help these amazingly feisty little creatures - and I describe them that way with the utmost respect - have the resources they need during their migration across the landscape."

With a reputation as one of the continent's most determined and assertive birds, the rufous hummingbird, scientifically known as Selasphorus rufus, weighs less than a nickel and tops out at about 3 inches long. Based on its body length, its migratory journey is one of the world's longest - the hummingbirds that travel the full extent of the range, from Alaska to Mexico, migrate almost 80 million body lengths, or 3,900 miles.

By comparison, an arctic tern covers about 51 million body lengths on the 13-inch bird's one-way flight of 11,000 miles.

Rufous hummingbirds live in open woodlands, nest in trees and eat nectar. A common visitor to bird feeders, the extremely territorial rufous hummingbird will chase away much larger species of hummingbirds, and they'll even drive squirrels away from their nesting areas.

Equipped with excellent memories, rufous hummingbirds will visit the same feeders over multiple years, even looking for food at former locations of feeders that have been moved.

The study by scientists in the Oregon State University College of Forestry and at the Klamath Bird Observatory in Ashland looked at 15 years' worth of fall migration banding data involving nearly 30,000 hummingbird captures at more than 450 locations.

The research showed that adult females tended to have a southbound migration route that was parallel to and between those of young and adult males, Rousseau said.

"Also, a greater number of young birds migrated south through California in comparison to adult females and adult males," she said. "Our results suggest that the migration of each age-sex category is separated by about two weeks, with adult males migrating first, followed by adult females, and then the young of both sexes. Interestingly, though, migration speed was not statistically different among the categories."

The adult males were captured within a smaller geographic distribution during any given week of migration compared with adult females and young birds, she added.

They've been used as an educational toy for hundreds of years and are thought to develop skills such as hand-eye coordination and problem solving.

But little has been known about how children learn to do jigsaw puzzles.

Now, new research led by the University of East Anglia (UEA) has put jigsaw puzzles to the test - and found that children only learn to do them once they have reached a certain stage of development.

The study, published today in the journal Child Development, reveals that three-year-olds use trial and error, but four-year olds are able to use information in the picture to complete the puzzles. The research team say this understanding is the foundation of drawing and painting.

Lead researcher Dr Martin Doherty, from UEA's School of Psychology, said: "We looked at children's ability to do jigsaw puzzles. Surprisingly, there's virtually no research on this, despite the common assumption these are good educational toys.

"We were interested in children's understanding of pictures as representations. Jigsaws require assembly of a picture, so if children understand how pictures work then they should be better at jigsaw puzzles."

The team, which includes researchers from the Universities of Edinburgh Napier, West of Scotland and Warwick, worked with 169 children aged between three and five, to see how they put together different types of puzzles at different ages.

Some of the children worked on traditional jigsaw puzzles with a picture, jigsaws with no picture, and picture-based puzzles made up of equal-sized rectangular pieces. Half of this group were given a picture guide showing what the completed image should look like.

The researchers recorded how long it took the children to complete the puzzles and the number of times they attempted to join puzzle pieces.

Another group of children were given a jigsaw puzzle with a piece missing, and different options to fill the gap.

The children were also tested on their level of representational understanding, including how well they understood other people's beliefs. The researchers argue that understanding the relationship between a belief and the part of the world it is about develops alongside understanding the relationship between a picture and what it is about.

Dr Doherty said: "This is the first investigation of how children do jigsaw puzzles, and we were particularly interested in how they use their understanding of pictures to complete them.

"We found that children who passed tests for representational understanding were able to complete picture jigsaws faster and more efficiently. In general, efficiency increased between the ages of three and five years.

"The really unique thing about this study is that we are showing the age and stage of development at which children gain a fundamental understanding of the nature of pictures.

"We think this lays a vital foundation for learning to draw and paint," he added.

When used correctly, the symptomatic case fatality ratio (sCFR) and the infection fatality ratio (IFR) are better measures by which to monitor COVID-19 epidemics than the commonly reported case fatality ratio (CFR), according to a new study published this week in PLOS Medicine by Anthony Hauser of the University of Bern, Switzerland, and colleagues.

Reliable estimates of the mortality from SARS-CoV-2 infection are essential to understand the COVID-19 epidemic and develop public health interventions. However, the commonly used CFR--the number of reported deaths divided by the number of reported cases--can be a misleading measure of mortality associated with COVID-19. In the new study, researchers developed a computational model of the dynamics of transmission of SARS-CoV-2 along with COVID-19 associated mortality. The model took into account the delay between infection and death, the increased diagnosis of disease in people with severe symptoms, and stratified data by age.

The researchers applied the model to Hubei province (China), Austria, Bavaria (Germany), Baden- Württemberg (Germany), Lombardy (Italy), Spain and Switzerland. In Hubei, the calculated IFR was 2.9% (95% credible interval [CrI] 2.4-3.5) while the CFR was 2.4%. In Europe, estimates of the IFR ranged from 0.5 (95% CrI 0.4-0.6) to 1.4% (95% CrI: 1.1-1.6) while the CFR ranged from 3.9% to 17.8%. Overall, estimates of sCFR and IFR were similar to each other and varied less geographically than the CFR.

"The CFR is not a good predictor of overall mortality from SARS-CoV-2 and should not be used for evaluation of policy or comparison across settings," the authors say. "The sCFR and IFR, adjusted for [the right biases], are measures that can be used to improve and monitor clinical and public health strategies to reduce the deaths from SARS-CoV-2 infection."

KINGSTON, R.I., -- July 28, 2020 -- For decades, scientists have gathered ancient sediment samples from below the seafloor to better understand past climates, plate tectonics and the deep marine ecosystem. In a new study published in Nature Communications, researchers reveal that given the right food in the right laboratory conditions, microbes collected from sediment as old as 100 million years can revive and multiply, even after laying dormant since large dinosaurs prowled the planet.

The research team behind the new study, from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), the URI Graduate School of Oceanography, the National Institute of Advanced Industrial Science and Technology, the Kochi University and Marine Works Japan, gathered the ancient sediment samples ten years ago during an expedition to the South Pacific Gyre, the part of the ocean with the lowest productivity and fewest nutrients available to fuel the marine food web.

"Our main question was whether life could exist in such a nutrient-limited environment or if this was a lifeless zone," said the paper's lead author Yuki Morono, senior scientist at JAMSTEC. "And we wanted to know how long the microbes could sustain their life in a near-absence of food."

On the seafloor, there are layers of sediment consisting of marine snow (organic debris continually sourced from the sea surface), dust, and particles carried by the wind and ocean currents. Small life forms such as microbes become trapped in this sediment.

Aboard the research drillship JOIDES Resolution, the team drilled numerous sediment cores 100 meters below the seafloor and nearly 6,000 meters below the ocean's surface. The scientists found that oxygen was present in all of the cores, suggesting that if sediment accumulates slowly on the seafloor at a rate of no more than a meter or two every million years, oxygen will penetrate all the way from the seafloor to the basement. Such conditions make it possible for aerobic microorganisms--those that require oxygen to live--to survive for geological time scales of millions of years.

With fine-tuned laboratory procedures, the scientists, led by Morono, incubated the samples to coax their microbes to grow. The results demonstrated that rather than being fossilized remains of life, the microbes in the sediment had survived, and were capable of growing and dividing.

"We knew that there was life in deep sediment near the continents where there's a lot of buried organic matter," said URI Graduate School of Oceanography professor and co-author of the study Steven D'Hondt. "But what we found was that life extends in the deep ocean from the seafloor all the way to the underlying rocky basement."

Morono was initially taken aback by the results. "At first I was skeptical, but we found that up to 99.1% of the microbes in sediment deposited 101.5 million years ago were still alive and were ready to eat," he said.

With the newly developed ability to grow, manipulate and characterize ancient microorganisms, the research team is looking forward to applying a similar approach to other questions about the geological past. According to Morono, life for microbes in the subseafloor is very slow compared to life above it, and so the evolutionary speed of these microbes will be slower. "We want to understand how or if these ancient microbes evolved," he said. "This study shows that the subseafloor is an excellent location to explore the limits of life on Earth."

Before looking ahead to future research, D'Hondt took time to reflect on Morono's achievement. "What's most exciting about this study is that it shows that there are no limits to life in the old sediment of the world's ocean," said D'Hondt. "In the oldest sediment we've drilled, with the least amount of food, there are still living organisms, and they can wake up, grow and multiply."

This study was supported by the Japan Society for the Promotion of Science (JSPS), the Funding Program for Next Generation World-Leading Researchers, and the U.S. National Science Foundation. This study was conducted using core samples collected during Expedition 329, "South Pacific Gyre Subseafloor Life," of the Integrated Ocean Drilling Program.