Natural selection alters genes that control roundworms' sense of smell

Charles Darwin was right.

In his 1859 book, "On the Origin of Species," the famed scientist hypothesized that artificial selection (or domestication) and natural selection work in the same ways.

Now an international team, led by Northwestern University, has produced some of the first evidence that Darwin's speculation was correct.

This time, the study's subjects are not exotic birds in the Galapagos, but instead a roundworm, which relies on its sense of smell to assess the availability of food and nearby competition. In the Northwestern-led work, researchers found that natural selection acts on the same genes that control wild roundworms' sense of smell as were previously found in domesticated worms in the lab.

"The evolution of traits if rarely connected to exact genes and processes," said Northwestern's Erik Andersen, who led the study. "We offer a clear example of how evolution works."

The scientists used a combination of laboratory experiments, computational genomic analysis and field work. Their research also shows that natural selection acts on signal-sensing receptors rather than the downstream parts of the genetic process.

The study published this week (Sept. 23) in the journal Nature Ecology & Evolution. Andersen is an associate professor of molecular biosciences in Northwestern's Weinberg College of Arts and Sciences.

A keystone model organism, C. elegans is a one-millimeter-long roundworm that lives in decaying organic matter -- particularly rotten fruits -- and feeds on bacteria. These roundworms are typically found in gardens and compost piles.

For C. elegans, having a keen sense of smell can be the difference between life or death. If they smell enough food in their environment, then they will stay, grow and reproduce. If they sense a shortage of food and/or too much competition from other worms, then they will undertake a long and potentially fatal journey in search of a more favorable environment. This process, called "dauer," delays growth and reproduction.

In other words, dauer decreases reproductive success in the short term in order to ensure survival in the long run.

"At some point in their lives, these worms must make a gamble," Andersen said. "In the time it takes for a worm to come out of dauer and start growing again, the worm that stayed behind has already been multiplying. If the food runs out, then the dauer worm made the right decision and wins. If the food doesn't run out, then the dauer worm loses."

Andersen and his collaborators found that evolution plays a significant role in a worm's decision to stay or enter dauer. Some roundworms have one genetic receptor to process scents; other roundworms have two. The roundworms with two receptors have a heightened sense of smell, which allows them to better assess the availability of resources in their environment and make a better gamble.

"If worms can smell large numbers of worms around them, that gives them an advantage," Andersen said. "This was discovered in a previous study of artificial selection in worms. Now we also found that result in natural populations. We can see specific evidence in these two genes that artificial and natural selection act similarly."

A little kindness goes a long way for worker performance and health

Small gestures of kindness by employers can have big impacts on employees' health and work performance, according to an international team of researchers. The team specifically examined the effects of employers enhancing the lunches of bus drivers in China with fresh fruit and found that it reduced depression among the drivers and increased their confidence in their own work performance.

"An ultimate solution to improve worker performance and health could be big pay raises or reduced workloads, but when those solutions aren't feasible, we found that even small offerings can make a big difference," said Bu Zhong, associate professor of journalism at Penn State.

According to Zhong, bus drivers are vulnerable to specific health problems due in large part to their stressful working environment, which often includes irregular shift schedules, unpredictable traffic conditions and random meal times. In addition, the sedentary nature of driving and continuous whole-body vibration contributes to fatigue, musculoskeletal problems such as lower-back pain, cardiovascular diseases and gastrointestinal issues.

Zhong and his colleagues conducted an experiment with 86 Shenzen bus drivers. During the experiment, on-duty bus drivers were given, in addition to their typical box lunch which includes no fruit, a serving of fresh fruit -- either an apple or a banana -- for three weeks. The cost of the fruit was 73 cents per meal.

The team distributed surveys to the bus drivers at three time intervals -- one week before the experiment began, once in the middle of the three-week-long experiment and one week following the end of the experiment. The findings appear today in the International Journal of Occupational Safety and Ergonomics.

The researchers assessed depression with a personal health questionnaire that is recommended by the U.S. Centers for Disease Control and Prevention. The scale consisted of eight items, asking the participants to rate, for example, how often during the past two weeks they felt down, depressed or hopeless, and had trouble falling or staying asleep.

"Bus drivers reported significantly decreased depression levels one week after the experiments ended compared to one week before it began," said Zhong.

The team measured self-efficacy -- perceived confidence and ability to implement the necessary actions and tasks so as to achieve specific goals -- using the 10-item General Self-Efficacy Scale. Items on this scale included, "I can always manage to solve difficult problems if I try hard enough" and "I can usually handle whatever comes my way."

"We found that self-efficacy was significantly higher in the middle of the experiment week than in the week after the experiment ended," said Zhong.

Zhong concluded that while eating an extra apple at lunchtime may seem trivial, its impact can be large.

"This research suggests that employees can be sensitive to any improvement at the workplace," he said. "Before an ultimate solution is possible, some small steps can make a difference -- one apple at a time."

Virtual reality training could improve employee safety

A new study suggests employee safety could be improved through use of Virtual Reality (VR) in Health and Safety training, such as fire evacuation drills.

The Human Factors Research Group at the University of Nottingham, developed an immersive VR system to stimulate participants' perception of temperature, and senses of smell, sight and hearing to explore how they behaved during two health and safety training scenarios: an emergency evacuation in the event of a fire and a fuel leak.

In one scenario, participants had to evacuate from a virtual fire in an office, seeing and hearing using a VR headset but could also feel heat from three 2kW heaters, and could smell smoke from a scent diffuser, creating a multisensory virtual environment. This group was compared against another group who were observed in this scenario using only audio-visual elements of VR.

Observing real life behaviours

Previous research on human behaviour during real-world fire incidents has shown that a lack of understanding of the spread and movement of fire often means that occupants are unprepared and misjudge appropriate actions. Immersive health and safety training enables employers to train people about hazards and hazardous environments without putting anyone at risk.

The Nottingham research, funded by the Institution of Occupational Safety and Health (IOSH), found contrasts between the groups in the way participants reacted to the scenario. Those in the multi-sensory group had a greater sense of urgency, reflecting a real-life scenario, and were more likely to avoid the virtual fires. Evidence from the audio-visual participants suggested that they were treating the experience more like a game and behaviours were less consistent with those expected in a real world situation.

Dr Glyn Lawson, Associate Professor in the Faculty of Engineering, University of Nottingham, said: "Health and safety training can fail to motivate and engage employees and can lack relevance to real-life contexts. Our research, which has been funded by the Institution of Occupational Safety and Health, suggests that virtual environments can help address these issues, by increasing trainees' engagement and willingness to participate in further training. There are also business benefits associated with the use of virtual environment training, such as the ability to deliver training at or near the workplace and at a time that is convenient to the employee."

Virtual Reality vs. PowerPoint

A further test was done, as part of the study, to measure the effectiveness of VR training versus traditional PowerPoint training. Participants took questionnaires, testing their knowledge on either fire safety or safe vehicle disassembly procedure, before and after training as well as one week later.

While those trained via PowerPoint appeared to have gained more knowledge when tested directly after training, there was a significantly larger decrease in knowledge scores when participants were retested one week later. In comparison, the VR group's long term retention was better and reported higher levels of engagement; attitude to occupational safety and health; and willingness to undertake training in the future.

The research suggests that the increased cognitive engagement of learning in the virtual environment creates more established and comprehensive mental models which can improve recall, and implies that testing an employee's knowledge immediately following health and safety training may not be an effective means of gaging long-term knowledge of health and safety.

Applications to the work place

Mary Ogungbeje, Research Manager at IOSH, said: "The wheels are turning so that virtual and smart learning is increasingly engrained in the workplace and everyday life.

"Technology is continuously advancing and in many cases becoming more affordable, so this study gives us a taste of what's to come. By improving training strategies with the use of technology and stimulated sensory experiences, we are heading in a direction where the workforce will not just enjoy a more immersive and interesting training course but participate in an effective learning experience, so they are better prepared and equipped to stay safe, healthy and well at work."

The researchers conducted meetings, discussions, and visits with partners including Rolls-Royce, for expert advice around fire safety and safe handling of hazardous chemicals. The University of Nottingham's Health and Safety advisors also contributed to help the researchers better understand how the training may be implemented in industry.

The study aims to produce evidence-based guidance for the development and use of virtual environments in engaging and effective training using cost-effective and accessible solutions. The full study features in a report, titled 'Immersive virtual worlds: Multisensory virtual environments for health and safety training', to be released at the IOSH's annual conference on Tuesday 17 September.

The future of 'extremely' energy-efficient circuits

Data centers are processing data and dispensing the results at astonishing rates and such robust systems require a significant amount of energy -- so much energy, in fact, that information communication technology is projected to account for 20% of total energy consumption in the United States by 2020.

To answer this demand, a team of researchers from Japan and the United States have developed a framework to reduce energy consumption while improving efficiency.

They published their results on July 19 in Scientific Reports, a Nature journal.

"The significant amount of energy consumption has become a critical problem in modern society," said Olivia Chen, corresponding author of the paper and assistant professor in the Institute of Advanced Sciences at Yokohama National University. "There is an urgent requirement for extremely energy-efficient computing technologies."

The research team used a digital logic process called Adiabatic Quantum-Flux-Parametron (AQFP). The idea behind the logic is that direct current should be replaced with alternating current. The alternating current acts as both the clock signal and the power supply -- as the current switches directions, it signals the next time phase for computing.

The logic, according to Chen, could improve conventional communication technologies with currently available fabrication processes.

"However, there lacks a systematic, automatic synthesis framework to translate from high-level logic description to Adiabatic Quantum-Flux-Parametron circuit netlist structures," Chen said, referring to the individual processors within the circuit. "In this paper, we mitigate that gap by presenting an automatic flow. We also demonstrate that AQFP can achieve a reduction in energy use by several orders of magnitude compared to traditional technologies."

The researchers proposed a top-down framework for computing decisions that can also analyze its own performance. To do this, they used logic synthesis, a process by which they direct the passage of information through logic gates within the processing unit. Logic gates can take in a little bit of information and output a yes or no answer. The answer can trigger other gates to respond and move the process forward, or stop it completely.

With this basis, the researchers developed a computation logic that takes the high-level understanding of processing and how much energy a system uses and dissipates and describes it as an optimized map for each gate within the circuit model. From this, Chen and the research team can balance the estimation of power needed to process through the system and the energy that the system dissipates.

According to Chen, this approach also compensates for the cooling energy needed for superconducting technologies and reduces the energy dissipation by two orders of magnitude.

"These results demonstrate the potential of AQFP technology and applications for large-scale, high-performance and energy-efficient computations," Chen said.

Ultimately, the researchers plan to develop a fully automated framework to generate the most efficient AQFP circuit layout.

"The synthesis results of AQFP circuits are highly promising in terms of energy-efficient and high-performance computing," Chen said. "With the future advancing and maturity of AQFP fabrication technology, we anticipate broader applications ranging from space applications and large-scale computing facilities such as data centers."

Investments to address climate change are good business

An internationally respected group of scientists have urgently called on world leaders to accelerate efforts to tackle climate change. Almost every aspect of the planet's environment and ecology is undergoing changes in response to climate change, some of which will be profound if not catastrophic in the future.

According to their study published in Science today, reducing the magnitude of climate change is also a good investment. Over the next few decades, acting to reduce climate change is expected to cost much less than the damage otherwise inflicted by climate change on people, infrastructure and ecosystems.

"Acting on climate change" said lead author, Prof Ove Hoegh-Guldberg from the ARC Centre for Excellence in Coral Reef Studies at the University of Queensland in Australia "has a good return on investment when one considers the damages avoided by acting."

The investment is even more compelling given the wealth of evidence that the impacts of climate change are happening faster and more extensively than projected, even just a few years ago. This makes the case for rapidly reducing greenhouse gas emissions even more compelling and urgent.

Prof Hoegh-Guldberg explained the mismatch. "First, we have underestimated the sensitivity of natural and human systems to climate change, and the speed at which these changes are happening. Second, we have underappreciated the synergistic nature of climate threats -- with the outcomes tending to be worse than the sum of the parts. This is resulting is rapid and comprehensive climate impacts, with growing damage to people, ecosystems, and livelihoods."

For example, sea-level rise can lead to higher water levels during storm events. This can create more damage. For deprived areas, this may exacerbate poverty creating further disadvantage. Each risk may be small on its own, but a small change in a number of risks can lead to large impacts.

Prof Daniela Jacob, co-author and Director of Climate Services Centre (GERICS) in Germany is concerned about these rapid changes -- especially about unprecedented weather extremes.

"We are already in new territory" said Prof Jacob, "The 'novelty' of the weather is making our ability to forecast and respond to weather-related phenomena very difficult."

These changes are having major consequences. The paper updates a database of climate-related changes and finds that there are significant benefits from avoiding 2oC and aiming to restrict the increase to 1.5oC above pre-industrial global temperatures.

Prof Rachel Warren from the Tyndall Centre at the University of East Anglia in the UK assessed projections of risk for forests, biodiversity, food, crops and other critical systems, and found very significant benefits for limiting global warming to 1.5oC rather than 2oC.

"The scientific community has quantified these risks in order to inform policy makers about the benefits of avoiding them," Prof Warren stated.

Since the Paris Agreement came into force, there has been a race to quantify the benefits of limiting warming to 1.5oC so that policy makers have the best possible information for developing the policy required for doing it.

Prof Warren continued. "If such policy is not implemented, we will continue on the current upward trajectory of burning fossil fuels and continuing deforestation, which will expand the already large-scale degradation of ecosystems. To be honest, the overall picture is very grim unless we act."

A recent report from the United Nations projected that as many as a million species may be at risk of extinction over the coming decades and centuries. Climate change is not the only factor but is one of the most important ones.

The urgency of responding to climate change is at front of mind for Prof Michael Taylor, co-author and Dean of Science at the University of the West Indies. "This is not an academic issue, it is a matter of life and death for people everywhere. That said, people from small island States and low-lying countries are in the immediate cross-hairs of climate change."

"I am very concerned about the future for these people," said Professor Taylor.

This urgency to act is further emphasized by the vulnerability of developing countries to climate change impacts as pointed out by Francois Engelbrecht, co-author and Professor of Climatology at the Global Change Institute of the University of the Witwatersrand in South Africa.

"The developing African countries are amongst those to be affected most in terms of impacts on economic growth in the absence of strong climate change mitigation," Prof Engelbrecht explains.

Prof Hoegh-Guldberg reiterated the importance of the coming year (2020) in terms of climate action and the opportunity to strengthen emission reduction pledges in line with the Paris Agreement of 2015.

"Current emission reduction commitments are inadequate and risk throwing many nations into chaos and harm, with a particular vulnerability of poor peoples. To avoid this, we must accelerate action and tighten emission reduction targets so that they fall in line with the Paris Agreement. As we show, this is much less costly than suffering the impacts of 2oC or more of climate change."

"Tackling climate change is a tall order. However, there is no alternative from the perspective of human well-being -- and too much at stake not to act urgently on this issue."