The science behind swimming: From whales to larvae, common principles at work in swimming

Whale and diver (stock illustration). Using simple hydrodynamics, researchers were able to show that a handful of principles govern how virtually every animal -- from the tiniest fish to birds to gigantic whales propel themselves though the water. Credit: © James Thew / Fotolia

At nearly 100 feet long and weighing as much as 170 tons, the blue whale is the largest creature on the planet, and by far the heaviest living thing ever seen on Earth. So there's no way it could have anything in common with the tiniest fish larvae, which measure millimeters in length and tip the scales at a fraction of a gram, right?

Not so fast, says L. Mahadevan, the Lola England de Valpine Professor of Applied Mathematics, of Organismic and Evolutionary Biology, and of Physics.

Using simple hydrodynamics, a team of researchers led by Mahadevan was able to show that a handful of principles govern how virtually every animal -- from the tiniest fish to birds to gigantic whales propel themselves though the water. The study is described in a September 14 paper in Nature Physics.

"What we wanted to investigate was how the speed of an organism changes as a function of how large it is, how quickly it moves and how much it moves," Mahadevan said. "To resolve that in detail, however, is very complex, because there is a great deal of differences in morphology and what parts of the body different creatures use to swim. The question is: Is there anything in common across all these organisms? The answer, we found, is yes."

In an effort to uncover those common principles, Mahadevan working with a postdoctoral fellow in his group , Mattia Gazzola, and a colleague Mederic Argentina from the University of Nice, began by trying to unpack the physics of how different creatures swim.

"The traditional approach to swimming phenomena is to take a certain specimen and accurately characterize it via experiments and/or simulations, and try to generalize from there, but it is very hard to strip out specific biological effects from general principles," Gazzola said. "We instead thought that while swimmers exhibit a huge diversity in shapes and kinematics, at the end of the day they all live in the same media, water.

"Therefore we thought that if a unifying mechanistic principle existed, it had to lie in the constraints that the flow environment poses to all its inhabitants," he continued. "And this is a purely physical problem, much easier to solve since it is not affected by biological vagaries. What I like about this paper is that in one line of algebra we derived a compact formula that accounts for 50 years of experiments. This is an example of how powerful minimal modeling can be."

"The basic relationship we wanted to understand was how the input variables -- namely the size of the organism, the amount an organism moves and how quickly it moves -- control the output variable, which is effectively the speed at which it moves," Mahadevan explained. "What we found is that there is a specific relationship, which can be described by in terms of a simple scaling law with two limits."

The first, which corresponds to creatures moving at intermediate speeds, describes situations where the bulk of the resistance is caused by skin friction, because water "sticks" to the organism's body. At faster speeds, Mahadevan said, the resistance organisms face largely comes from pressure that builds up in front of and around them, which is described by the second limit.

"While it wasn't a surprise that the resistance changed at organisms moved faster, the fact that those challenges could be so simply described was interesting and provocative, because we are talking about organisms that range in size from a few millimeters to the size of a blue whale," Mahadevan said.

Armed with those observations, Mahadevan and colleagues turned to a host of empirical observations that had been made over the past 50-plus years. When those data were plotted on a graph, the researchers found that the swimming speed of virtually every organism, from fish larvae to frogs to birds, amphibians and even whales, could be described by one of the two equations.

The same also held true, Mahadevan said, when Gazzola created complex computer models to solve the governing equations of fluid dynamics to describe how different organisms swim.

"What is particularly interesting is that all the organisms essentially reach the hydrodynamic limits of performance," he said. "Our simple theory, which doesn't distinguish in any detailed way between something like a blue whale and fish larvae, except in the parameters of how large you are, much you move and how quickly you move, can describe all this diversity. That suggests there are general principles at work here."


Source: Harvard University

Scientists estimate total weight of plastic floating in world's oceans: Nearly 269,000 tons of plastic pollution floating in the ocean

Model results for global count density in four size classes. Model prediction of global count density (pieces km−2; see colorbar) for each of four size classes (0.33–1.00 mm, 1.01–4.75 mm, 4.76–200 mm, and >200 mm). Credit: Marcus Eriksen et al, PLoS ONE, 2014; DOI: 10.1371/journal.pone.0111913

Nearly 269,000 tons of plastic pollution may be floating in the world's oceans, according to a study published December 10, 2014 in the open-access journal PLOS ONE by Marcus Eriksen from Five Gyres Institute and colleagues.

Microplastic pollution is found in varying concentrations throughout the oceans, but estimates of the global abundance and weight of floating plastics, both micro and macroplastic, lack sufficient data to support them. To better estimate the total number of plastic particles and their weight floating in the world's oceans, scientists from six countries contributed data from 24 expeditions collected over a six-year period from 2007-2013 across all five sub-tropical gyres, coastal Australia, Bay of Bengal, and the Mediterranean Sea. The data included information about microplastics collected using nets and large plastic debris from visual surveys, which were then used to calibrate an ocean model of plastic distribution.

Based on the data and model, the authors of the study estimate a minimum of 5.25 trillion plastic particles weighing nearly 269,000 tons in the world's oceans. Large plastics appear to be abundant near coastlines, degrading into microplastics in the 5 subtropical gyres, and that the smallest microplastics were present in more remote regions, such as the subpolar gyres, which the authors did not expect. The distribution of the smallest microplastics in remote regions of the ocean may suggest that gyres act as 'shredders' of large plastic items into microplastics, after which they eject them across the ocean.

"Our findings show that the garbage patches in the middle of the five subtropical gyres are not the final resting places for the world's floating plastic trash. The endgame for micro-plastic is interactions with entire ocean ecosystems," says Marcus Eriksen, PhD, Director of Research for the 5 Gyres Institute.

Source: PLOS

Put a plastic bag in your tank: Converting polyethylene waste into liquid fuel

Researchers in India have developed a relatively low-temperature process to convert certain kinds of plastic waste into liquid fuel as a way to re-use discarded plastic bags and other products.

Researchers in India have developed a relatively low-temperature process to convert certain kinds of plastic waste into liquid fuel as a way to re-use discarded plastic bags and other products. They report full details next month in the International Journal of Environment and Waste Management.

Many pundits describe the present time as the "plastic age" for good reason and as such we generate a lot plastic waste. Among that waste is the common polymer, low-density polyethylene (LDPE), which is used to make many types of container, medical and laboratory equipment, computer components and, of course, plastic bags. Recycling initiatives are in place in many parts of the world, but much of the polyethylene waste ends up in landfill, dispersed in the environment or in the sea.

Chemist Achyut Kumar Panda of Centurion University of Technology and Management Odisha, India is working with chemical engineer Raghubansh Kumar Singh of the National Institute of Technology, Orissa, India, to develop a commercially viable technology for efficiently rendering LDPE into a liquid fuel. Given that most plastics are made from petrochemicals, this solution to plastic recycling brings the life-cycle full circle allowing a second use as an oil substitute. The process could, if implemented on a large enough scale, reduce pressures on landfill as well as ameliorating the effects of dwindling oil supplies in a world with increasing demands on petrochemicals for fuel.

In their approach, the team heats the plastic waste to between 400 and 500 Celsius over a kaolin catalyst. This causes the plastic's long chain polymer chains to break apart in a process known as thermo-catalytic degradation. This releases large quantities of much smaller, carbon-rich molecules. The team used the analytical technique of gas chromatography coupled mass spectrometry to characterize these product molecules and found the components of their liquid fuel to be mainly paraffins and olefins 10 to 16 carbon atoms long. This, they explain, makes the liquid fuel very similar chemically to conventional petrochemical fuels.

In terms of the catalyst, Kaolin is a clay mineral -- containing aluminum and silicon. It acts as a catalyst by providing a large reactive surface on which the polymer molecules can sit and so be exposed to high temperature inside the batch reactor, which breaks them apart. The team optimized the reaction at 450 Celsius a temperature with the lowest amount of kaolin at which more than 70% of the liquid fuel is produced. In other words, for every kilogram of waste plastic they could produce 700 grams of liquid fuel. The byproducts were combustible gases and wax. They could boost the yield to almost 80% and minimize reaction times, but this required a lot more catalyst 1 kg of kaolin for every 2 kg of plastic.

Source: Inderscience Publishers

The Loss of biodiversity limits toxin degradation

You might not think of microbes when you consider biodiversity, but it turns out that even a moderate loss of less than 5% of soil microbes may compromise some key ecosystem functions and could lead to lower degradation of toxins in the environment.

Research published today in the SfAM journal, Environmental Microbiology, reports that without a rich diversity of soil bacteria, specialized functions such as the removal of pesticide residues are not as effective.

Dr Brajesh Singh of the University of Western Sydney led the work, he said "If the ability of the ecosystem to remove toxins from the environment is reduced, there will be higher toxicity risks in the environment and for non-target organisms, including humans, from agricultural chemicals. It is likely that these contaminants will remain at higher levels in surface and underground water, as well. It is vital to gain a better understanding of the extent to which soil bacteria are involved in the removal of contaminants."

The reasons for, and extent of, the decline in microbial diversity in agricultural soils is likely to be complex. The team has looked specifically at long-term heavy metal pollution where metals such as cadmium, zinc, and copper build up in the environment, usually as a result of industrial use. Another source is from digested sewage sludge, which is spread in agriculture fields to supply nutrients to crops and improve soil fertility; the sludge has historically contained some heavy metals, which can become concentrated in the soil.

Although the concentration of heavy metal used this study was higher than the current EU limit, this study has confirmed that long-term exposure to such contaminants does reduce the diversity of bacteria in the soil.

With the global population set to reach nine billion by 2050, we face a challenge to feed an extra two billion mouths using the same resources that we have at present. Crop losses to pests and disease account for a large percentage of under-production and so giving up pesticides will be difficult. Similarly, the use of sludge as a fertilizer is likely to become more prevalent. Research like this allows us to understand better how to use important agrichemicals and waste products in a sustainable way and so will contribute to future food and environmental security.

Source: Wiley

Bald reef gets new growth with seaweed transplant

Transplanted seaweed is attached to a reef by a team member. Credit: Image courtesy of University of New South Wales

Marine ecologists in Sydney have successfully restored a once thriving seaweed species, which vanished along a stretch of the city's coastline during the 1970s and 80s when there were high levels of sewage.

A team of researchers from UNSW, the Sydney Institute of Marine Science and the NSW Department of Primary Industries has transplanted fertile specimens of the missing crayweed (Phyllospora comosa) onto two barren reef sites where it once grew abundantly.

They took seaweed from Palm Beach and Cronulla and transplanted it to Long Bay and Cape Banks. Their results are reported in the journal PLOS ONE.

"Seaweeds are the 'trees' of the oceans, providing habitat structure, food and shelter for other marine organisms, such as crayfish and abalone," says lead author, Dr Alexandra Campbell, from the UNSW Centre for Marine Bio-Innovation.

"The transplanted crayweed not only survived similarly to those in natural populations, but they also successfully reproduced. This creates the potential for a self-sustaining population at a place where this species has been missing for decades," she says.

Large brown seaweeds -- known as macroalgae -- along temperate coastlines, like those in NSW, also encourage biodiversity and are important to the region's fishing and tourism industries.
However, these seaweed ecosystems face increasing threats of degradation due to human impacts and ocean warming. The authors say the potential environmental and economic implications of losing these habitats would be comparable to the more highly publicised loss of Australia's tropical coral reefs.

In 2008, researchers from UNSW and the NSW Department of Primary Industries (DPI) showed that a 70 km stretch of this important habitat-forming crayweed had vanished from the Sydney coast decades earlier, coinciding with a period known for high levels of sewage.

Despite improved water quality around Sydney after the introduction of better infrastructure in the 1990s, which pumped sewage into the deeper ocean, the 70 km gap of depleted 'underwater forest' -- between Palm Beach and Cronulla -- has never been able to recover naturally.

Now, with some well-executed intervention, it looks as though this habitat-forming crayweed could make a successful comeback in Sydney's coastal waters.

"This is an environmental good news story," says research supervisor UNSW Professor Peter Steinberg, Director of the Sydney Institute of Marine Science.

"This kind of restoration study has rarely been done in these seaweed-dominated habitats, but our results suggest that we may be able to assist in the recovery of underwater forests on Sydney's reefs, potentially enhancing biodiversity and recreational fishing opportunities along our coastline."

The researchers say their results could provide valuable insights for restoring similar macroalgae marine ecosystems in Australia and globally, but further research is needed to understand the complex processes that affect recruitment and survival.

This project was funded in part by a grant from the NSW Recreational Fishing Trust.


Source:  University of New South Wales

Updating air pollution measurement methods

Launching a natural research experiment in Kathmandu, Nepal, this month using advanced monitoring methods to assess health risk from air pollution, environmental health scientist Rick Peltier at the University of Massachusetts Amherst hopes to demonstrate for the first time in a real-world setting that air pollution can and should be regulated based on toxicology variables rather than simply on the volume of particles in the air.

Recent technological advances in air quality measurement methods now make it possible and practical to monitor air pollution in a much more sophisticated way than before, Peltier says. Researchers now use X-ray fluorescence spectrometry to measure air pollution metal content, ion chromatography to identify other chemicals and other tactics to assess organic and elemental carbon levels.

Peltier says, "We're interested in how air pollution directly affects health. The current regulatory method doesn't take into account the relative toxicity of components, that is the specific chemical makeup of the air we breathe. There has been a void in the science in this field. But with this experiment, for the first time we'll have biological measurements coupled with high-quality air pollution measurements in a cohort of traffic police exposed to extreme levels of pollution."

At present, the Environmental Protection Agency monitors air quality components every three days at 350 stations across the United States, but there are no such sites in Nepal. Particulates are an important signature of traffic. A poor air quality day in Los Angeles may see 40-50 micrograms of particulates per cubic meter, Peltier says, while in Kathmandu the level can be 800-900, or about 20 times worse.

Ethically, the environmental scientist adds, it would be impossible to expose people to such pollution levels in a laboratory-based experiment, and ambient levels such as those typically observed in Kathmandu are never routinely encountered anywhere in the United States. Peltier and colleagues' study will take advantage of the fact that the traffic officers already are exposed to high air pollution levels in their normal workday.

Funded by a multinational partnership led by UMass Amherst and including the Himalayan region's Intergovernmental Centre for Integrated Mountain Development (ICIMOD) and the Institute for Advanced Sustainability Studies in Potsdam, Germany, the investigation will follow a cohort of 32 traffic control officers in Kathmandu during two seasons: Cold, dry winter from this month into March, with a second study in the hot, rainy monsoon season from June to August, when air pollution levels are lower.

Peltier observes that Nepal's capital city region has poor air quality because two-stroke gasoline and diesel engines, high pollutant emitters, are common. Also, people heat their homes with coal and kerosene and routinely burn garbage and tires outdoors. For the 3 million inhabitants this poses substantial, demonstrable health risks.

"Unfortunately, the Kathmandu metropolitan area has quite poor air quality, and it's in a valley so it is a persistent problem," he adds. "We hypothesize that toxicity is related to the chemical components of pollution. We know this is true in a Petri dish, but now we'll be able to measure it in study subjects."
Participants are 16 men and 16 women, 25 to 35 years old who have similar education and income levels. For a six-day work week, each will carry a small waist pack containing research-grade, solar-powered portable air samplers. The filters will be collected for airborne metals, ions, organic carbon and black carbon analysis. The experiment will include an intervention component, as well: For half of each study week, participants will wear high-quality, particle-filtering face masks that greatly reduce air pollution exposure.

In addition to the air filters, researchers will collect blood samples and ask the traffic officers to use a spirometer several times a day to assess lung function. Their location, activity and electrocardiogram will be continuously measured in both conditions: Breathing polluted air with and without protective face masks.

Air quality samples and the health measurement data will be analyzed at UMass Amherst and compared between the different exposure conditions. Peltier and his postdoctoral fellow Kabindra Shakya will collaborate with researcher Arnico Panday of ICIMOD, Kathmandu, which along with UMass Amherst supported the work, plus Maheswar Rupakheti of the sustainability institute in Potsdam.

Source: University of Massachusetts 

Scientists uncover hidden river of rubbish threatening to devastate wildlife

The sheer amount of plastic recovered shows there is an unseen stream of rubbish flowing through London which could be a serious threat to aquatic wildlife. Credit: Image courtesy of University of Royal Holloway London

Thousands of pieces of plastic have been discovered, submerged along the river bed of the upper Thames Estuary by scientists at Royal Holloway, University of London and the Natural History Museum.

The sheer amount of plastic recovered shows there is an unseen stream of rubbish flowing through London which could be a serious threat to aquatic wildlife. The findings, published online in Marine Pollution Bulletin, highlight the cause for concern, not only for ecosystems around the river but for the North Sea, in to which the Thames flows.

Using nets designed to catch Chinese mitten crabs, Royal Holloway and the Natural History Museum scientists documented rubbish collected during a three-month trial. More than 8,000 pieces of plastic were collected, including large numbers of cigarette packaging, food wrappers and cups, but more than a fifth of waste was made up of sanitary products.

Dr Dave Morritt, a Senior Lecturer in Marine Biology at Royal Holloway and co-author of the study says: "The unusual aspect of the study is that these nets are originally designed to trap fish and crabs moving along the river bed, so we can see that the majority of this litter is hidden below the surface. This underwater litter must be taken into account when predicting the amount of pollution entering our rivers and seas, not just those items that we can see at the surface and washed up on shore. The potential impacts this could have for wildlife are far reaching: not only are the species that live in and around the river affected, but also those in seas that rivers feed into."

The waste collected for the study is only a small snapshot of the volume of litter which may exist at the bottom of the Thames. Plastic bags and other large items were unlikely to get caught in the small nets so the true extent of the problem is still unknown.

Dr Paul Clark, a researcher, at the Natural History Museum and co-author of the study says: "All of this waste, which was mostly plastic, was hidden underwater so Londoners probably don't realise that it's there. Plastic can have a damaging impact on underwater life. Large pieces can trap animals but smaller pieces can be in advertently eaten. This litter moves up and down the river bed depending on tides. The movement causes the pieces of plastic to break down into smaller fragments. These are small enough to be eaten by even the smallest animals, which are in turn eaten by larger fish and birds. Once digested, plastic can release toxic chemicals which are then passed through the food chain. These toxic chemicals, in high doses, could harm the health of wildlife."

Scientists are increasingly pressing for changes to both policy and consumer behaviours, as the dangers of plastics become more apparent.

Source: University of Royal Holloway London

Recovering metals and minerals from waste

When water and wastewater systems are developed in a comprehensive manner, it is possible to recover valuable metals and other materials and secure availability of clean water.

Scarcity of clean water is one of the most serious global challenges. In its spearhead programme, VTT Technical Research Centre of Finland developed energy-efficient methods for reuse of water in industrial processes and means for recovering valuable minerals and materials from waste for recycling. Rapid tools were also developed for identification of environmental pollutants.

When water and wastewater systems are developed in a comprehensive manner, it is possible to recover valuable metals and other materials and secure availability of clean water. Cleaning and treatment processes can also be linked to energy production, and the processes and urban structures designed in such a manner that wastewater treatment does not consume energy or cause extra costs.

"Wastewater treatment and waste treatment have mainly been implemented by legal necessity. Now we should modify our way of thinking so that we would be able to regard waste disposal sites and purification plants as sources or raw materials and energy. In the near future, technology has been refined far enough to allow such waste treatment plants to operate on their own," says Mona Arnold, Principal Researcher at VTT.

Recycling valuable minerals and materials

Demand has arisen for technologies capable of recovering even tiny amounts of minerals from waste flows. Recovering them from municipal or mining wastewaters requires better recovery methods than those available today. VTT has developed extraction methods for metals and minerals from waste materials. Biological extraction methods by which metals are recovered from mining, metal and recycling industry waste by utilising microbes and chemical reactions are under testing stages and they are forcasted for market uptake within the next few years.

Other valuable elements can also be found from waste flows. For example, the food industry by-product flows contain biochemicals and proteins that can be utilised better than is currently possible, if only they could be effectively recovered from waste. One possibility is to use enzymes. VTT researchers developed an enzyme-assisted method by which feed products can be produced from side streams deriving from turnip rape processing in food industry.

Reducing energy consumption in water treatment

Treatment of water in purification plants and industrial facilities consumes vast amounts of energy. Usually water recycling and seawater desalination are based on the use of filtration membranes that consume energy. VTT developed intelligent membrane materials, reducing the need of purification, for filtration purposes.

Membrane solutions using only small amounts of energy were developed for water treatment purposes. VTT has collaborated with a university in Singapore to develop a method based on forward osmosis technology, by which metals and biocomponents can be recovered and concentrated from industrial process waters.

The pumping and distribution of water to consumers and industry also consumes major amounts of energy. The need for pumping can be minimised if the process water can be recirculated within the plant, and the distribution network is made more effective by enhanced monitoring and location of leaks.

Sensors for identifying environmental hazards

The VTT spearhead programme also developed sensor technology for easy and rapid detection of pollutants. VTT indicators facilitate rapid identification of, for example, small but hazardous cyanobacterial toxin levels and phenolic, hormone-like compounds. There is need for such indicators in developing countries, suffering from lack of trained personnel and laboratories. The technology will be ready for production use within the next few years.

Source: Technical Research Centre of Finland (VTT).

The Wastewater injection is culprit for most earthquakes in southern Colorado and northern New Mexico, study finds

The deep injection of wastewater underground is responsible for the dramatic rise in the number of earthquakes in Colorado and New Mexico since 2001, according to a study to be published in the Bulletin of the Seismological Society of America (BSSA).


The Raton Basin, which stretches from southern Colorado into northern New Mexico, was seismically quiet until shortly after major fluid injection began in 1999. Since 2001, there have been 16 magnitude > 3.8 earthquakes (including M 5.0 and 5.3), compared to only one (M 4.0) the previous 30 years. The increase in earthquakes is limited to the area of industrial activity and within 5 kilometers (3.1 miles) of wastewater injection wells.

In 1994, energy companies began producing coal-bed methane in Colorado and expanded production to New Mexico in 1999. Along with the production of methane, there is the production of wastewater, which is injected underground in disposal wells and can raise the pore pressure in the surrounding area, inducing earthquakes. Several lines of evidence suggest the earthquakes in the area are directly related to the disposal of wastewater, a by-product of extracting methane, and not to hydraulic fracturing occurring in the area.

Beginning in 2001, the production of methane expanded, with the number of high-volume wastewater disposal wells increasing (21 presently in Colorado and 7 in New Mexico) along with the injection rate. Since mid-2000, the total injection rate across the basin has ranged from 1.5 to 3.6 million barrels per month.

The authors, all scientists with the U.S. Geological Survey, detail several lines of evidence directly linking the injection wells to the seismicity. The timing and location of seismicity correspond to the documented pattern of injected wastewater. Detailed investigations of two seismic sequences (2001 and 2011) places them in proximity to high-volume, high-injection-rate wells, and both sequences occurred after a nearby increase in the rate of injection. A comparison between seismicity and wastewater injection in Colorado and New Mexico reveals similar patterns, suggesting seismicity is initiated shortly after an increase in injection rates.

Source: Seismological Society of America

Oklahoma earthquakes induced by wastewater injection by disposal wells, study finds

House damage in central Oklahoma from the magnitude 5.6 earthquake on Nov. 6, 2011. Credit: Brian Sherrod, USGS

The dramatic increase in earthquakes in central Oklahoma since 2009 is likely attributable to subsurface wastewater injection at just a handful of disposal wells, finds a new study to be published in the journal Science on July 3, 2014.

The research team was led by Katie Keranen, professor of geophysics at Cornell University, who says Oklahoma earthquakes constitute nearly half of all central and eastern U.S. seismicity from 2008 to 2013, many occurring in areas of high-rate water disposal.

"Induced seismicity is one of the primary challenges for expanded shale gas and unconventional hydrocarbon development. Our results provide insight into the process by which the earthquakes are induced and suggest that adherence to standard best practices may substantially reduce the risk of inducing seismicity," said Keranen. "The best practices include avoiding wastewater disposal near major faults and the use of appropriate monitoring and mitigation strategies."

The study also concluded:

• Four of the highest-volume disposal wells in Oklahoma (~0.05% of wells) are capable of triggering ~20% of recent central U.S. earthquakes in a swarm covering nearly 2,000 square kilometers, as shown by analysis of modeled pore pressure increase at relocated earthquake hypocenters.
• Earthquakes are induced at distances over 30 km from the disposal wells. These distances are far beyond existing criteria of 5 km from the well for diagnosis of induced earthquakes.
• The area of increased pressure related to these wells continually expands, increasing the probability of encountering a larger fault and thus increasing the risk of triggering a higher-magnitude earthquake.

"Earthquake and subsurface pressure monitoring should be routinely conducted in regions of wastewater disposal and all data from those should be publicly accessible. This should also include detailed monitoring and reporting of pumping volumes and pressures," said Keranen. 'In many states the data are more difficult to obtain than for Oklahoma; databases should be standardized nationally. Independent quality assurance checks would increase confidence. "

Source: Cornell University