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Desalination has social benefits – and costs, too

A team from the United Arab Emirates, which has limited natural water resources and uses desalination to make seawater drinkable, looked at cases from several countries to identify these factors and their influence on desalination around the world, publishing their findings in the journal Desalination.

“Although the economic and environmental factors have received more attention, there is evidence to suggest that the use of desalination technologies and their associated impacts would most likely exacerbate the existing inequalities in a society,” says Yazan Ibrahim, a former graduate student and research engineer at Khalifa University who joined New York University, Abu Dhabi, for his Ph.D. in 2021.

RELATED: Solar-powered desalination plants could help achieve global water security

“This was attributed to the increased greenhouse-gas emissions, increased water prices, urban-growth motivation, shifting geopolitical relations related to water security and increased chemical pollution,” he says. The research team used a SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis as the framework for a critical review of the sociopolitical factors that impact the adoption and proliferation of desalination.

A SWOT analysis is typically employed to help gain insights into the strengths and opportunities of an initiative or concept as well as the associated weaknesses and threats.

“We defined ‘sociopolitical’ factors as factors with a significant social dimension, which have either underlying social, economic or political root causes and consequences within those spheres,” Ibrahim says. “We identified eight strengths and opportunities, and seven weaknesses and threats.”

The strengths and opportunities include fast deployment and low physical footprint that comes with some desalination technologies with the potential to help remote communities and tourist facilities flourish.

Many factors are at play when it comes to the sociopolitical dimension of desalination. A holistic approach to this subject is essential.

– Yazan Ibrahim, researcher

Desalination can significantly enhance the water security of a nation, while also supporting regional stabilities by evading conflict over water resources.

Local employment opportunities during the construction and operation of desalination plants are another benefit, but easy access to water also means more work and education opportunities for women who might otherwise be tasked with the time-consuming work of sourcing and carrying water.

Most-cited weaknesses include the visual impacts, noise and land-use issues. Beyond this: the unintended consequences of excessive reliance on desalination and the potential impacts of poor mineralization of desalinated water on human health.

Freshwater contains minerals that may offer health benefits, and it’s not yet understood if desalinated water that has not been re-mineralized could have adverse health effects.

Threats to desalination also stem from social tension among those who mistrust the technologies as well as the wide range of human and natural threats to operation ranging from cyberattacks to natural disasters and oil spills.

The team’s research makes it clear that aside from political stability, water security and economic growth, desalination can also boost tourism, agriculture and education.

“Since its inception, desalination has delivered a range of benefits to societies in arid regions and supported their economic development and political stability. It must be recognized, however, that many factors are at play when it comes to the sociopolitical dimension of desalination. A holistic approach to this subject is essential,” Ibrahim says.

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In the world of smart everything,
fingertips are no exception

Virtual reality has given us the sensations of sight and sound, but now engineers have created a sensory fingertip to mimic the sense of touch.

The team of Chinese researchers used the practical example of being able to virtually pet a cat. They said that one of the motivators of this project was the isolation of COVID-19 lockdowns and the possibility to, at least virtually, hug a family member.

While previous technology consisted of bulky gloves, the fingertips, similar to the thickness of human skin, let the wearer feel pressure, vibration and textures. By adjusting the frequency and voltage of the signal, they are able to mimic the roughness of certain textures like sandpaper or rocks or the smoothness of silk or glass. The results were published in the September 2022 edition of Science Advances.

This technology could be used on gloves to assist the likes of firefighters, astronauts or deep-sea divers whose bulky, insulated safety suits interfere with the sense of touch, the team says.

It is very hard to mimic the feeling of sustained pressure without vibration.

– Weikang Lin, researcher

Weikang Lin, the lead researcher on the paper, discusses the challenge of simulating the sensation of holding a mobile phone: If it is held for a time, sustained pressure will be felt, but if it starts to vibrate, the vibration will be felt and the pressure ignored. “It is very hard to mimic the feeling of sustained pressure without vibration,” Weikang tells KUST Review.

A common weakness of electrical-based stimulators is the inability to precisely stimulate one kind of receptor without activating others, says Zhengbao Yang, one of the researchers on the project. “In our future work, we want to overcome this challenge.”

The team also envisions a Braille tool for the visually impaired or a virtual shopping experience whereby the shopper can feel the fabric of the clothes.

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Research challenges assumptions about
condition that leaves people speechless

There are several areas of the brain understood to play a critical role in speech and language. One of these is Broca’s area, which is located in the left hemisphere and is associated with speech production and articulation.

The human ability to articulate ideas, as well as use words accurately in spoken and written language, has been attributed to Broca’s area, which is named after the French physician who discovered it in 1861 – Pierre Paul Broca. His work on the left frontal lobe of the brain revealed that the brains of people suffering from aphasia – a loss of language affecting a person’s ability to speak, read and write, which is brought about by neurological damage caused by a stroke – contained lesions in a particular part of the cortex, now named Broca’s area. This was the first anatomical proof of localization of brain function.

Given the importance of Broca’s area for language processing abilities, it was widely accepted that damage to this area impairs speech production.

However, an international team that included researchers from University College London (UK), Universidad del Desarrollo (Chile) and Khalifa University (UAE), have challenged the long-held assumption that damage to Broca’s area contributes to long-term speech production impairments after a stroke.

“For over 150 years, clinical aphasiology and behavioral neurology have been influenced by Broca’s finding that stroke survivors with severe and persistent speech impairments had damage to Broca’s area,” says Mohamed Seghier, a professor in KU’s Department of Biomedical Engineering. IMAGE: National Cancer Institute for Unsplash

Through their investigation, they discovered that long-term aphasia is not caused by damage to Broca’s area but to damage to neighboring regions, due to the large functional connectivity of this area with adjacent frontal and subcortical areas. They published their work in the journal Brain.

“For over 150 years, clinical aphasiology and behavioral neurology have been influenced by Broca’s finding that stroke survivors with severe and persistent speech impairments had damage to Broca’s area,” says Mohamed Seghier, a professor in KU’s Department of Biomedical Engineering.

“Broca was not able to define the exact extent of the lesions in his patients because, being aware of their historical relevance, he decided not to dissect the specimens but preserve them for future research. His descriptions, therefore, focused on the parts of the lesions that were visible to him, without evaluating the potential contribution of neighboring damage, for example, to the underlying white matter and surrounding cortical areas. It was not until 2007 that the full extent of the lesions incurred by Broca’s two famous cases was revealed in an MRI study showing damage to multiple subcortical gray and white matter regions.”

The research team’s findings confirm that the degree of damage in the surrounding brain tissue – the white- and gray-matter regions – rather than damage to Broca’s area, is associated with long-term aphasia.

White matter is the tissue through which messages pass between different areas of the central nervous system, including the brain. Gray matter contains most of the brain’s neuronal cell bodies and is involved in muscle control and sensory perception such as seeing and hearing, speech and decision-making.

The team wanted to test whether damage to Broca’s area contributes to speech-production impairments that persist for at least three months after a left frontal lobe stroke.

– Mohamed Seghier, professor in Khalifa University’s Department of Biomedical Engineering

The team members investigated their hypothesis by examining whether impediments to speech production were worse in stroke survivors who had damage to Broca’s area but not surrounding regions, or who had damage to both Broca’s area and surrounding regions.

Prior research has found that the overwhelming majority of Broca’s aphasia patients present extended brain damage, significantly exceeding the Broca’s area, leading researchers to conclude that lesions restricted to Broca’s area are associated with just mild defects in language production. A stroke will typically damage multiple neighboring brain regions to the Broca’s area, and in all cases of stroke it is difficult to determine which part of the lesion site is driving the observed behavioral deficits.

The team members investigated their hypothesis by examining whether impediments to speech production were worse in stroke survivors who had damage to Broca’s area but not surrounding regions, or who had damage to both Broca’s area and surrounding regions.

Prior research has found that the overwhelming majority of Broca’s aphasia patients present extended brain damage, significantly exceeding the Broca’s area, leading researchers to conclude that lesions restricted to Broca’s area are associated with just mild defects in language production. A stroke will typically damage multiple neighboring brain regions to the Broca’s area, and in all cases of stroke it is difficult to determine which part of the lesion site is driving the observed behavioral deficits.

To tackle this problem, the research team studied a large number of stroke survivors who all had left frontal lobe damage but differed in the degree of damage to Broca’s area and surrounding areas. Their selection of brain areas was based on a combination of anatomical and functional evidence and the white matter linking the different areas of the brain responsible for speech.

“Unlike previous studies, our analyses were aimed at disentangling how speech-production abilities, months after a stroke on the left frontal lobe, were affected by damage to Broca’s area and the degree to which such effects were influenced by damage also occurring to a specific set of neighboring regions,” Seghier says. “The team wanted to test whether damage to Broca’s area contributes to speech-production impairments that persist for at least three months after a left frontal lobe stroke.”

The team’s work found that evidence in favor of damage to Broca’s area not explaining variance in speech-production abilities was eight times stronger than the alternative. The researchers concluded this is positive evidence for the absence of a unique long-lasting effect of Broca’s area damage on speech-production abilities. The absence of evidence became evidence of absence, showing that the prior association between Broca’s area damage and long-lasting speech impairments can be attributed to co-occurring damage to white matter.

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Holograms could help reduce
the need for food packaging

A team of researchers has developed a way to print edible holograms onto food using lasers and corn syrup, a process that could someday be used to reduce packaging needs if labels and nutrition information could be printed directly on the food item.

Holographic chocolate is already common among chocolatiers wanting to make an aesthetic impact. The process works by molding edible holograms onto the surface of the chocolate, imprinting patterns that cause light to diffract into the classic rainbow pattern. However, this process works only for certain types of chocolate, and traditional holograms – imprinting on metal surfaces – requires a volume of metal that renders food inedible.

Instead researchers looked to find a safe, fast and versatile way to print edible holograms on all kinds of foods.

The researchers developed a method involving a thin film of dried corn syrup, vanilla and water, which they then coated with a layer of black dye. Most of this dye was etched off using lasers, leaving behind raised lines of dye on the film. When struck by light, these lines diffracted the light into the rainbow pattern, with different colors appearing at different angles. The team members found they could control the intensity and range of colors by varying the pattern etched into the dye or by changing the sugar content of the corn syrup film.

The research team will now adapt the method to a food-grade dye that could replace the black dye used in these experiments so that holographic food can become a staple on the shelves.

The work was published in American Chemical Society Nano and funded by Khalifa University, Sandooq Al Watan, Aldar Properties and the Engineering and Physical Sciences Research Council.

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Camels switch off their kidneys
to survive dehydration threats

To better understand how the Arabian camel manages to preserve water, a team from University of Bristol, United Arab Emirates University and Khalifa University examined the genes in the kidneys of Arabian camels exposed to chronic dehydration to determine how the animals can survive long periods of time in harsh conditions without access to water and what humanity could possibly learn from this.

The results were published in Communications Biology.

“Extensive evidence shows the impressive set of adaptations that allows a camel to thrive in desert environments, despite sometimes needing to survive for weeks without access to water,” says team lead Abdu Adem, Ph.D., a professor of pharmacology at Khalifa University. “Behavioral and physiological adaptations ensure that water is never wasted. Camels will only eat the leaves of plants, they avoid exposure to direct sunlight where possible, restrict reproduction to the cooler winter season, and drink very large amounts of water when available to compensate for any fluid deficiency from their desert wandering.”

Camels have been known to drink 30 gallons of water in just 13 minutes, but even here they have an evolutionary adaptation to avoid osmotic shock, or a sudden change in the solute concentration around a cell: They absorb the water very slowly.

The kidney that plays the largest role in conserving water for a camel, and it is from the camel kidney that humans can take inspiration. IMAGE: Unsplash

An intricate nasal passage prevents too much water loss when the camel breathes out, but more importantly, water evaporates from the surface of the nostrils to moisturize dry air when the camel breathes in, helping to cool the blood in the veins of the nose.

Thanks to thin blood-vessel walls, this cooler venous blood can help cool the blood in the arteries leading to the brain, meaning the camel’s brain is considerably lower in temperature than the body core.

Even the red blood cells themselves have a special shape shown to be advantageous in withstanding dehydration.

On top of all this, camels rarely sweat, even in the searing temperatures of the desert, all helping to conserve water.

Our analysis suggests that genes with known roles in water conservation are affected by changes in cholesterol levels. Suppressing the production of cholesterol may help the kidney retain water.

– Abdu Adem, Khalifa University professor of pharmacology

Yet, despite all these advantages, it is the kidney that plays the largest role in conserving water for a camel, and it is from the camel kidney that humans can take inspiration.

“In the current context of climate change, there is renewed interest in the mechanisms that enable camels and camelids to survive in arid conditions,” Adem says. “We investigated the camel kidney to see how gene expression has been influenced by chronic dehydration and rapid rehydration. Our analysis suggests that genes with known roles in water conservation are affected by changes in cholesterol levels. Suppressing the production of cholesterol may help the kidney retain water.”

Yet, despite all these advantages, it is the kidney that plays the largest role in conserving water for a camel, and it is from the camel kidney that humans can take inspiration.

“In the current context of climate change, there is renewed interest in the mechanisms that enable camels and camelids to survive in arid conditions,” Adem says. “We investigated the camel kidney to see how gene expression has been influenced by chronic dehydration and rapid rehydration. Our analysis suggests that genes with known roles in water conservation are affected by changes in cholesterol levels. Suppressing the production of cholesterol may help the kidney retain water.”

Camels produce highly concentrated urine, preserving as much water as possible. To produce such urine, the kidney must possess certain anatomical features.

Previous research has shown that the kidney of a young camel differs in structure from that of an adult, suggesting that the differences may be related to a greater degree of water deprivation experienced by adult animals. This would suggest that chronic dehydration causes genes in the adult camel kidney to be expressed differently, allowing the kidney to better preserve water.

The research team noted that the amount of cholesterol in the kidney has a role in the water-conservation process. In dehydrated camel kidneys, there was less cholesterol in the kidney membranes, and the genes that control the production of cholesterol were suppressed.

“We found remarkable changes in the amounts of specific genes and proteins in the kidney of the one-humped Arabian camel during severe dehydration and subsequent acute rehydration,” Adem says. “Our data suggests that the suppression of genes involved in cholesterol biosynthesis and the subsequent reduction in membrane cholesterol are a global response in the kidney to dehydration.”

We found remarkable changes in the amounts of specific genes and proteins in the kidney of the one-humped Arabian camel during severe dehydration and subsequent acute rehydration.

– Abdu Adem

Several ion channels and transporters are regulated by changes in the level of cholesterol in the cell. Dehydration and excessive heat cause electrolyte imbalances in the body, and the kidneys are one factor in keeping electrolyte levels balanced.

If there is an increase of cholesterol in the membrane of the kidney, movement through the ion channels is blocked. When cholesterol levels are lowered, water and electrolytes can move across different parts of the kidney, which helps reabsorb water and produce a highly concentrated urine.

The researchers found that during the summer, the gene that regulates the production of a protein called aquaporin 2 is expressed more, presumably in preparation for the more challenging conditions of the season.

Aquaporin 2 forms a channel in cell membranes to allow water molecules to pass through. During periods of dehydration, aquaporin 2 channels are inserted into the membranes of kidney cells, which allows water to be reabsorbed into the bloodstream, making the urine more concentrated.

The researchers found that when cholesterol was depleted, aquaporin 2 levels increased.

When the camel rehydrates, the gene expression is suppressed, the channels close and the expression of cholesterol synthesis genes returns to normal levels.

While this new knowledge contributes to our understanding of the immense evolutionary advantages the Arabian camel uses to survive in the desert, it could more importantly help humanity better adapt to advancing desertification amid climate change. Understanding the mechanisms of water control in dehydration could allow us to apply the principles to water conservation across a wide variety of disciplines.