Iodine accelerates formation of cloud condensation nuclei in the atmosphere

International research team reports effect of iodine-organic chemistry on the generation of new particles in the marine atmosphere and the recycling of iodine during particle growth

JOHANNES GUTENBERG UNIVERSITAET MAINZ


image: Clouds over the Atlantic view more


Credit: photo/©: Hoffmann group


The natural cycles of exchange of substances between the biosphere and the atmosphere are of major relevance to the Earth's climatic system. Perhaps the best-known example of this is the carbon cycle that involves the transfer of carbon between the atmosphere, the land biosphere, and the oceans. This cycle is responsible for ensuring that temperatures on our planet's surface are hospitable to life. However, there are also other important cycles of elements, such as that of sulfur. The emission of sulfur compounds from marine phytoplankton assumedly leads to the generation of water vapor-based condensation nuclei in the marine atmosphere, resulting in cloud formation. In other words, there is a natural feedback system that contributes to the stabilization of the Earth's surface temperatures. An international team of researchers has now identified a further element associated with marine algae that exhibits remarkably interlinked cyclical reactions in the marine atmosphere. This element is iodine. Their findings have been published recently in Proceedings of the National Academy of Sciences (PNAS).

Iodine is a halogen and thus belongs to a group of elements present in larger concentrations in seawater. Although the levels of iodine are far lower than those of, for instance, chlorine in the form of sea salt, this iodine exhibits certain unusual chemical features. "Initially, the process is similar to that of the sulfur cycle," explained Professor Thorsten Hoffmann of Johannes Gutenberg University Mainz (JGU). Marine phytoplankton convert the iodate present in the oceans into iodide, presumably so that they can employ this iodide as a simple inorganic antioxidant to protect their own cell walls. Iodide present at the water surface then also reacts with atmospheric ozone, releasing molecular iodine. This molecular iodine, through a succession of rapid atmospheric reactions, is transformed into iodine oxide, a substance that is very prone to take the form of aerosol particles. "These particles can grow into larger particles that can serve as cloud condensation nuclei and thus influence cloud formation," added Hoffmann. "However, in the case of iodine, in contrast with sulfur, the corresponding process is by no means at an end at this point."

Does iodine catalyze new particle formation?

In their PNAS article, the authors describe how a notable fraction of the molecular iodine formed in the growing atmospheric particles of the already generated iodine oxides is recycled back into the gas phase. "As far as we are currently able to establish, iodine is the only element that does not leave the atmosphere after being released from the Earth's surface but can be returned to the gas phase through redox reactions while it is still in the particle phase," clarified Hoffmann, who is a professor at JGU's Department of Chemistry. This means that iodine may well act as a significant catalyst when it comes to cloud formation. A series of unresolved questions remains, however. Among other things, it is still unclear to what extent human activity, which intervenes in this process at various points, impacts on this unique iodine cycle.

Participating in the project were, in addition to researchers at Mainz University, their colleagues at the Chinese Academy of Sciences, the California Institute of Technology (Caltech) in Pasadena, and the University of Galway.

Related links:
https://www.blogs.uni-mainz.de/fb09-ac-hoffmann-eng/ – Research group of Professor Thorsten Hoffmann

Read more:
https://www.uni-mainz.de/presse/aktuell/11991_ENG_HTML.php – press release "Reversed ratio of chiral volatile organic compounds over the Amazon rainforest reveal insects as unexplored important source of forest emissions" (27 Aug. 2020) ;
https://www.uni-mainz.de/presse/aktuell/10593_ENG_HTML.php – press release "Scientists at Mainz University study ice cores as a climate archive" (20 Dec. 2019) ;
https://www.uni-mainz.de/presse/aktuell/9337_ENG_HTML.php – press release "Reinhart Koselleck Project funding for research into the growth of atmospheric nanoparticles" (1 Oct. 2019) ;
https://www.uni-mainz.de/presse/15768_ENG_HTML.php – press release "International research group shows that the aging of organic aerosols is caused by OH radicals" (5 Oct. 2012)

Teens with COVID-19 knowledge reported better well-being

Peer-Reviewed Publication

WASHINGTON STATE UNIVERSITY

PULLMAN, Wash. – A pandemic survey found that adolescents who answered more COVID-19 test questions correctly also reported lower stress, anxiety and depression as well as lower loneliness and fear of missing out, also known as FOMO.

For the study, published in the Journal of Child and Family Studies, Washington State University researchers surveyed 215 teens ages 14-17 across the U.S. in July 2020 during the early months of the pandemic.

“Knowledge was a good thing. The teens who did better on our quiz tended to report lower depression, anxiety and stress – just across the board,” said corresponding author Chris Barry, a WSU psychology professor. “This is a one-time snapshot, so we don't really know cause and effect, but one presumption is that having accurate information was connected to feeling a little bit more ease during that time.”

Barry and co-authors Zeinab Mousavi and Brianna Halter had participants first answer true or false questions about COVID-19, such as the ways that the virus spreads and its health risks. While there were some low scores on the test, the majority of the participants did well with an average score of 15 out of 18 correct, and 21.9% got all the answers correct. The participants then answered a range of questions about their well-being as well as their social media use.

While nearly all the teens, 98.1%, used social media in some form, those who had good COVID-19 knowledge and checked social media less frequently also reported the lowest levels of anxiety.

While it is difficult to know the reason behind this connection, the researchers said that one possibility was that teens with less accurate COVID-19 knowledge might have used social media more to find answers and in the process, absorbed more misinformation which contributed to their anxiety.

Social media likely has a mixed effect on teens’ well-being, said Mousavi, a research assistant in Barry’s lab and the first author on the study.

“There are so many factors with social media,” she said. “For instance, it's good that you are staying connected with your friends and getting some information, but maybe at a certain point it is making some things worse, giving you more anxiety, rather than helping you cope with the situation.”

The researchers also surveyed the teens’ parents to assess the level of lockdown measures the adolescents were under. They found that the more restrictive quarantine measures were associated with negative well-being for the teens, but that teens’ perceptions of the lockdown were particularly important for well-being. This indicates that perhaps the more that adolescents understood the reason for such measures, or perceived there to be some benefits, the more positive they felt in general, said Barry.

The findings underscore the need for parents and educators to give teens information especially in times of crisis, he added.

“In thinking about adolescent development in general, one of the things that we recommend from a developmental psychology perspective is open communication, so for the pandemic, that means honest, accurate information,” Barry said.

He also suggested that parents not only acknowledge the stress and feelings of isolation that may come with something like quarantine but also help teens make the most of the situation. For example, if their kids are missing out on events that were cancelled, parents could help them find other ways to socialize with friends or engage in recreational activities. They should also try to emphasize any potential positive sides of the experience.

“In an unusual situation like lockdowns, mindset matters,” he said.

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JOURNAL

Journal of Child and Family Studies

DOI

10.1007/s10826-022-02465-0 

ARTICLE TITLE

Relations of Adolescent Knowledge of COVID-19, Social Media Engagement, and Experiences During Quarantine/Lockdown with Well-Being

Now we know how plants steer clear of salt

Peer-Reviewed Publication

UNIVERSITY OF COPENHAGEN - FACULTY OF SCIENCE

 

IMAGE: THE ROOT EPIDERMAL CELLS OF THE TWISTING ROOTS view more 

CREDIT: WENNA ZHENG

To avoid salt in soil, plants can change their root direction and grow away from saline areas. University of Copenhagen researchers helped find out what makes this possible. The discovery changes our understanding of how plants change their shape and direction of growth and may help alleviate the accelerating global problem of high soil salinity on farmland.

 

Whereas a bath in the ultra-salty Dead Sea may be a balm for human soul and body, the relationship between most plants and salt is quite the opposite. Plants desperately do whatever they can to steer clear of salinity – as salts can damage and even suffocate them.

Unfortunately, salt in agricultural land is an accelerating global problem, partly due to climate change, which increases the salinity of soil whenever floods sweep coastal zones. Typically, this lowers crop yields.

"The world needs crops that can better withstand salt. If we are to develop plants that are more salt-tolerant, it is important to first understand the mechanisms by which they react to salt," explains Professor Staffan Persson of the University of Copenhagen’s Department of Plant and Environmental Sciences. He continues:

“To avoid salt in soil, plants can make their roots grow away from saline areas. It is a vital mechanism. Until now, it is unclear how they do this."

Together with a group of foreign research colleagues, Persson discovered exactly what happens inside plants at a cellular and molecular level as their roots grow away from salt. The results have been published in the scientific journal Developmental Cell.

 

Stress hormone comes into play

The research group has discovered that when a plant senses local concentrations of salt, the stress hormone ABA (abscisic acid) is activated in the plant. This hormone then sets a response mechanism into motion.

"The plant has a stress hormone triggered by salt. This hormone causes a reorganization of the tiny protein-based tubes in the cell, called the cytoskeleton. The reorganization then causes the cellulose fibers surrounding the root cells to make a similar rearrangement, forcing the root to twist in such a way that it grows away from the salt," explains Professor Persson. 

 

Changes the understanding of how plants change shape

The leading role played by the stress hormone is what makes the discovery a surprise for the researchers. Until now, it was believed that the hormone auxin controlled a plant’s ability to change directions in response to various environmental influences (known as tropisms). 

"That the stress hormone ABA is crucial for plants being able to reorganize their cell walls and change shape and direction of growth is completely new. This could open new avenues in plant research, where there will be a greater focus on the significant role that the hormone seems to play in the ability of plants to cope with various conditions by changing movement," says Staffan Persson.

By mutating a single amino acid in a protein that drives the twisting of the root, the researchers were able to reverse the twist so that the plant could not grow away from the salt.

Persson believes that it will be some time before the new knowledge is applied in agriculture – not least because GMOs remain banned in the EU. However, the results may open the way for the development of more salt-tolerant crop varieties.

"Plants produce more of the stress hormone when they sense salt. It's not hard to imagine that if you can speed up a plant's stress response by changing other aspects of the cytoskeleton, you can probably make its root-twist happen faster. In this way, we can strengthen plants by reducing their exposure to salt," says Professor Persson.

 

FACTS: About the study

• The ability of plants to grow toward or away from certain environmental stimuli is called tropism. Halotropism is the ability to grow away from salt. Other tropisms include responses to light (phototropism) and gravity (gravitropism).
   
• The experiments in the study were conducted on Arabidopsis plants using biotechnology and microscopy.
   
• The scientific research article about the study "Root twisting drives halotropism via stress-induced microtubule reorientation" has been published in the scientific journal Developmental Cell.
   
• From the University of Copenhagen, Postdoc Wenna Zheng and Professor Staffan Persson have contributed to the study.

 

FACTS:

• High salt concentrations in farmland are caused by several things, including the flooding of coastal areas due to climate change, as well as irrigation, which often increases soil salinity.
   
• The annual cost of land degradation due to salt in irrigated areas is estimated to be roughly $30 billion USD (source: www.un.org/en/observances/world-soil-day).

 

Wild-type seedlings were transferred to a split-agar medium without or with 200 mM NaCl

 

Microscopic images of roots

CREDIT

Bo Yu

JOURNAL

Developmental Cell

DOI

10.1016/j.devcel.2022.09.012 

ARTICLE TITLE

Root twisting drives halotropism via stress-induced microtubule reorientation

New pathway for global carbon neutrality: Radiative cooling

Peer-Reviewed Publication

SCIENCE CHINA PRESS

 

IMAGE: (A) THEORETICAL FRAMEWORK TO DESIGN IR-TRANSPARENT FABRIC. (B) SCHEMATIC OF POLYDOPAMINE AND NANO-POROUS POLYETHYLENE (PDA-NANOPE-MESH) WITH PERFORMANCE COMPARABLE WITH THAT OF COTTON. (C) DIAGRAM OF FACE MASKS WITH ELECTROSPUN NYLON-6 NANOFIBERS ON NEEDLE-PUNCHED NANOPE SUBSTRATE. (D) SCHEMATIC OF NANOPE FABRIC WITH HIGH MID-IR TRANSPARENCY, VISIBLE OPACITY AND GOOD WEARABILITY. (E) ZNO NPS EMBEDDED NANO-POROUS PE FABRIC. (F) SCHEMATIC FOR THE COLORATION OF RADIATIVE COOLING TEXTILES, WHICH IS MADE BY MIXING IR-TRANSPARENT INORGANIC PIGMENT NANOPARTICLES WITH PE. (G) DIRECT RADIATIVE COOLING USING IR-SELECTIVE TRANSPARENT COVERS. (H) SCHEMATIC OF HIGHLY IR-TRANSPARENT PE BUBBLE WARP TO BLOCK AMBIENT CONVECTIVE HEAT TRANSFER AND ENSURE THE RADIATIVE HEAT TRANSPORT FROM OBJECTS TO OUTER SPACE. (I) THE SELECTION OF FUNCTIONAL GROUPS FOR HIGH EMITTANCE AND LOW SOLAR ABSORPTION. view more 

CREDIT: ©SCIENCE CHINA PRESS

Increasing global warming and extreme weather are common challenges for humankind, directly affecting individual health and even posing serious threats to lives. Thermal comfort, heating ventilation and air conditioning systems requiring energy supply are widely used in space cooling, resulting in excessive consumption of fossil fuels and significant greenhouse gas emissions such as CO2. Massive greenhouse gas emissions have induced the rise of global temperature and climatic anomalies, significantly threatening the existence of life on the Earth. Hence, new cooling strategy is urgently needed to save energy and reduce emission to protect our living environment and achieve carbon neutrality visions. However, some renewable energy sources are limited by complex systems, geographical, environmental and stability issues. Therefore, in response to global warming and global carbon neutrality, there is an immediate need for new cooling technologies in sustainable carbon-neutral models to confront the issue of superheating as an effective strategy against the energy challenge.

To cope with these challenges, recently, the research team led by Prof. Guangming Tao (Wuhan National Laboratory for Optoelectronics and Optics Valley Laboratory, Huazhong University of Science and Technology) and Prof. Cheng-Wei Qiu (Department of Electrical and Computer Engineering, National University of Singapore) has proposed a potential radiative cooling paradigm based on structural and material design, and new opportunities for sustainable carbon neutrality as a zero-energy, ecologically friendly cooling strategy have also been presented. This technology uses broad-spectrum selective and precise regulation to meet the cooling needs of multiple scenes through targeted optimization of optical structures, ultimately achieving sustainable passive radiative cooling. Shortly after published, this article had already been cited in Wikipedia under the terms "Carbon neutrality" and "Passive daytime radiative cooling".

In order to achieve effective cooling, traditional indoor cooling methods consume large amounts of energy. Therefore, based on mid-infrared high-transmission radiation cooling, Chen, Cui and Lenert et al. designed wearable cooling devices to achieve passive and efficient indoor cooling by reflecting visible light as well as emitting heat radiation through the human body to the surrounding environment (Figure 1). However, passive cooling for hot outdoor environments is still a pressing issue.

In outdoor environments, strong solar radiation is another important factor that causes the temperature of object to rise in addition to thermal radiation. Therefore, Fan and Zhu et al. achieved passive cooling function by designing radiative cooling devices to precisely modulate solar radiation and mid-infrared radiation (Figure 2 c-e), but it is difficult to achieve low cost and mass fabrication. Yang, Zhu, and Tao et al. introduced randomly distributed micro and nanoscale scatterers for sustainable and efficient outdoor passive cooling when fabricated on a large scale (Figure 2 f-m). Scientists have developed thin film, coating, cooling wood, metafabric and other devices to achieve energy savings of 7% - 45% using stable and sustainable passive cooling recipes.

It has been established that peak CO2 emissions and subsequent carbon neutrality are predominant global challenges for future societal development. This review further discussed the future application scenarios of radiative cooling in the context of sustainable carbon neutrality strategies for passive and efficient space cooling needs and presents the development trends, technical challenges, and potential solutions for radiative cooling in the context of current research. The technology promises to be applied in all aspects of everyday life and extreme environments, which is a highly effective strategy for slowing global warming and reshaping the global energy landscape.

(a) Diagram of coating a metal surface with cheap plastic materials. (b) Enhanced convection of air beneath the black robes carries this heat away before it reaches the skin making it just as effective as the white robes. (c) Diagram of ultra-broadband metal-dielectric photonic structures. (d) Diagram of HfO2-SiO2 photonic film. (e) Diagram of visibly transparent silica photonic crystal. (f) Diagram of the scalable-manufactured glass-polymer hybrid metamaterial. (g) Diagram of hierarchically porous polymer coatings. (h) Diagram of the cooling wood structure. (i) A schematic diagram of the planar PDMS/metal thermal emitter. (j) Artificially fabricated radiative coolers based on the fluff structure of N. gigas. (k) Effective scattering diagram of micro- and nano-structures of the es-PEO film. (l) Hierarchical-morphology metafabric for scalable radiative cooling. (m) Diagram of the intrinsic molecular vibrations and porous structure of the cellulose acetate (CA) film.

Radiative cooling is applied in a series of everyday life and extreme scenarios.

©Science China Press

See the article:

Radiative cooling for passive thermal management towards sustainable carbon neutrality

https://doi.org/10.1093/nsr/nwac208

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JOURNAL

National Science Review

DOI

10.1093/nsr/nwac208 

What a ‘cat friendly’ veterinary experience looks like

Peer-Reviewed Publication

SAGE

 

IMAGE: A SOFT HAND IS EXTENDED BY THIS VETERINARY TEAM MEMBER TO INVITE THE CAT TO INITIATE CONTACT. THIS IS A MORE CAT FRIENDLY AND RESPECTFUL APPROACH THAN IMMEDIATELY PICKING UP AND RESTRAINING THE PATIENT. view more 

CREDIT: ELLEN CAROZZA LVT, VTS (CP-FELINE)

Good feline healthcare necessitates visiting the veterinary clinic, but many components of a veterinary visit or stay may potentially result in negative experiences. The impacts can be far-reaching, including distress and prolonged recovery from illness for the cat, and, for the veterinary team, the risk of misleading clinical findings and test results, possible injury and further difficulties with handling of the cat at future visits. Mounting evidence suggests that first veterinary visits can impact a young animal for life. 

The cat’s veterinary experience includes their journey to the clinic, their interactions with team members, the social environment (other animals in the waiting and hospitalisation areas), as well as the physical environment of the clinic. These aspects are all addressed in two ‘Cat Friendly Guidelines’1,2 published jointly by the International Society of Feline Medicine (ISFM) and the American Association of Feline Practitioners (AAFP). They appear in a Cat Friendly Special Issue of the Journal of Feline Medicine and Surgery (JFMS) and are available, together with a suite of supporting information and resources, at bit.ly/JFMSCatFriendly.

The ‘2022 AAFP/ISFM Cat Friendly Veterinary Interaction Guidelines: Approach and Handling Techniques’1 and ‘2022 ISFM/AAFP Cat Friendly Veterinary Environment Guidelines’2 are directed at veterinary professionals around the world. They are authored by experts in feline clinical medicine and behaviour, who have undertaken an extensive literature review and have also drawn on valuable experience gained in the 10 years that the ISFM’s Cat Friendly Clinic (catfriendlyclinic.org) and AAFP’s Cat Friendly Practice (catvets.com/cfp) programmes have been running and contributing so positively to feline health and wellbeing. To date, almost 3700 clinics and practices across 57 countries have achieved official ‘Cat Friendly’ status under the programmes.

At the heart of the new guidance – richly illustrated with images from some of these Cat Friendly Clinics and Practices – is the recognition that mental wellbeing is as equally important as physical health. The Cat Friendly Guidelines put the cat’s emotional experience at the forefront of all veterinary interactions, and integrate some new terminology: a cat’s positive emotions, which, for example, might lead them to explore the environment and seek food, treats, play and social interaction, are reframed as ‘engaging’ emotions, while the negative emotions of fear, anxiety, frustration and pain are referred to as ‘protective’ emotions. This approach will help the veterinary team to better understand the feline perspective, identify underlying stressors and establish what works to resolve the situation rather than exacerbate it.

To be truly cat friendly, all team members need an understanding of cats, not only as individuals, but as a species. Much of the characteristic behaviour of cats is derived from their wildcat ancestor, Felis silvestris lybica, in particular their natural preference to rely on themselves for protection. Familiarity, control, predictability and avoidance of threats all contribute to their perceived safety. In an unfamiliar situation, the preferred strategy for most cats is to escape. When this option is unavailable, such as in the veterinary clinic, they instead attempt to hide or to perch to monitor the environment from above.

The Cat Friendly Guidelines offer myriad practical tips for both minimising negative experiences and promoting positive experiences. ‘Thinking cat’ extends to educating the caregiver on how best to prepare the cat for their trip to the veterinary clinic, and is as fundamental as considering what the patient, with their highly tuned sensory system, will see, hear and smell during their visit to the clinic. The advice includes minimising visual stimulation – even pictures of cats and other animals can be perceived as threatening. Cats should be kept away from noisy patients and loud clinic equipment, and all human vocalisation should be soft, gentle and slow in tempo. For the majority of practices that treat dogs as well as cats, removing potentially challenging scents by sweeping up dog hair and emptying bins of strong-smelling waste, such as urine, is important, and synthetic feline pheromones can be used to help create a more reassuring environment. Importantly, adjustments to establish a more cat friendly veterinary environment need not be structural or expensive, and a range of ways of providing cat-only waiting areas and hiding and perching options in cages are suggested.

Likewise, the veterinary team need to remain ‘cat focused’ during all interactions. Being aware of cats’ preferred areas of touch – particularly in the region of the facial glands, which produce the pheromones used in social bonding – helps to encourage positive emotions during the clinical examination, while simple steps, such as not leaning over or cornering the cat, and avoiding direct eye contact, help to ease anxiety. Allowing the cat to remain in the bottom of their carrier, or using towels or a high-sided cat bed to encourage a sensation of being hidden and protected, can be very beneficial. Significantly, by practising cat friendly interactions and providing a cat friendly veterinary environment, equipment that historically has been used for cat restraint, including cat bags, gauntlets and muzzles, quickly comes to be replaced by items that provide the patient with comfort, a sense of safety and choice, and positive distractions. In certain situations, the use of anti-anxiety medication is also appropriate, and the Cat Friendly Guidelines discuss protocols for strategic use prior to or during the veterinary visit.

So, what next for cats, their caregivers and the veterinary team? The concept of ‘cooperative care’ is described as being the future for ‘cat friendly’. This will require new skills to be developed and practised, both at home and in the veterinary practice, to help cats feel more relaxed and in control in medical situations where they may naturally feel fearful and/or frustrated. More immediately, each veterinary team is encouraged to look at even the smallest adjustments they can make to their own veterinary environment and interactions to improve the experience for cats and their caregivers.

For the Cat Friendly Guidelines Co-Chairs, veterinarians Ilona Rodan, Nathalie Dowgray, Samantha Taylor and Kelly St Denis, the publication of the Cat Friendly Special Issue of JFMS is a pivotal moment. ‘We’re thrilled the Cat Friendly Guidelines will be available to all veterinary professionals because they are a game changer. They will enhance feline welfare, caregiver loyalty and human safety, and mean more positive veterinary visits for all!’

References

1. Rodan I, Dowgray N, Carney HC, et al. 2022 AAFP/ISFM cat friendly veterinary interaction guidelines: approach and handling techniques. J Feline Med Surg 2022; 24: 1093–1132. Available at: https://journals.sagepub.com/doi/full/10.1177/1098612X221128760.
2. Taylor S, St Denis K, Collins S, et al. 2022 ISFM/AAFP cat friendly veterinary environment guidelines. J Feline Med Surg 2002; 24: 1133–1163. Available at: https://journals.sagepub.com/doi/full/10.1177/ 1098612X221128763.

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JOURNAL

Journal of Feline Medicine and Surgery

DOI

10.1177/1098612X221128760 

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

2022 AAFP/ISFM Cat Friendly Veterinary Interaction Guidelines: Approach and Handling Techniques

ARTICLE PUBLICATION DATE

2-Nov-2022

Italian researchers discover new recipe for extending shelf life of fresh pasta by 30 days

Changes to product packaging, addition of bioprotective, and antimicrobial bacteria called probiotics add 30 days to how long the popular food staple can be stored

Peer-Reviewed Publication

FRONTIERS

Pasta is serious business in Italy, with reportedly more than 300 specific forms known by some 1,300 names. There is even a 55-year-old ‘pasta law’ that governs its production and manufacture. But that doesn’t mean the beloved food staple is shut off from innovation.

Now, Italian researchers have cooked up a new process for extending the shelf life of fresh pasta by 30 days, using a novel packaging process that also involves applying bioprotective probiotic cultures to the dough. They published this new recipe for better preserving fresh pasta in the journal Frontiers in Microbiology.

The problem with fresh pasta

Most fresh pasta sold in stores today is produced through an industrial process that includes heat-treating the product, essentially the equivalent of pasteurization for pasta. After the pasta is ready, it is stored in something called modified atmosphere packaging (MAP), which involves removing oxygen and replacing it with other gasses within a package consisting of plastic film.

If kept refrigerated, fresh pasta has a shelf life of between 30 and 90 days. However, plenty of things can go wrong to compromise the quality of the pasta and even safety of the product. Some bacteria may survive thermal treatment and grow under the right conditions such as too much moisture.

Sometimes chemical preservatives are also used to help retain freshness. However, for consumers who prefer natural, ‘clean label’ products without artificial or synthetic ingredients, the options available to extend shelf life of fresh pasta are limited.

MAPping out a new way to store pasta

Researchers at the National Research Council (CNR), the largest public research institution in Italy, together with the University of Bari Aldo Moro, and in collaboration with the private chemical laboratory, Food Safety Lab, developed a new ‘clean-label’ method to minimize spoilage problems. First, they changed the ratio of MAP gasses and combination of plastic films used in the packaging to better control microbial growth and impermeability. Finally, they added a multi-strain probiotic mixture to inhibit the growth of bacteria.

 

The scientists then tested the new protocol using a short, thin twisted pasta type called trofie. One set of fresh pasta was manufactured and packaged conventionally. A second set was manufactured traditionally but stored in the experimental MAP. They added the bioprotective probiotic strains to a third set of fresh trofie, which was then stored in the experimental packaging.

And then the scientists waited.

After a few months – and using high-tech methods such as gene sequencing to identify microbial compositions and mass spectrometry to profile volatile organic compounds – they found that the trofie pasta treated with antimicrobial bioprotective probiotics in the experimental MAP had the best shelf life of the three experiments.

“The results demonstrate that the MAP, together with a spray-dried probiotic bioprotective cultures, acted in a synergistic way to control the microbial spoilage of fresh pasta during refrigerated storage,” said Dr Francesca De Leo, a researcher with the Institute of Biomembrane, Bioenergetics and Molecular Biotechnologies at the CNR.

Fighting food waste

De Leo said that the technique developed by her team could be introduced at the industrial level, adding 30 days of shelf life compared to conventional products.

“From the consumer’s standpoint, a definite advantage of this product is the long shelf life and ease of storage,” she said. “This can be particularly important considering that consumers tend more and more to reduce the frequency of their food purchases, and consequently store as much as possible at home.”

The value of the research extends beyond finding a better way to store pasta longer, she added, by helping reduce food waste. The World Food Programme estimates that about a third of all food produced each year is squandered or lost before it can be consumed.

“Food waste and loss have a great influence on the ecological and environmental sustainability of the food system,” De Leo noted. “The adoption of innovative technological solutions for food waste prevention, such the one outlined in this study, can help offset these problems, if companies are willing to accept the challenge and innovate.”

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JOURNAL

Frontiers in Microbiology

DOI

10.3389/fmicb.2022.1003437 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Extension of the shelf-life of fresh pasta using modified atmosphere packaging and bioprotective cultures

ARTICLE PUBLICATION DATE

2-Nov-2022

New study reveals that physical activity in the afternoon or evening is linked to reduced insulin resistance (and thus better control of blood sugar)

Peer-Reviewed Publication

DIABETOLOGIA

A new study published in Diabetologia (the journal of the European Association for the Study of Diabetes [EASD]) finds that afternoon or evening physical activity is associated with reduced insulin resistance (and thus better blood sugar control) when compared with an even distribution of physical activity through the day. Morning physical activity offered no advantages, concluded the study by Dr Jeroen van der Velde and colleagues at Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands.

The current global obesity pandemic is partially the result of a lack of physical activity combined with sedentary behaviour (prolonged sitting) during the day. Such behaviour is linked to an increased risk of developing metabolic diseases including type 2 diabetes (T2D), while earlier research has found that short breaks in sedentary behaviour are associated with an improved cardiometabolic profile. This evidence is further supported by experimental studies showing that frequent interruptions of extended sitting with standing or light physical activity resulted in lower triacylglycerol levels and reduced blood glucose, indicating an improved blood sugar profile.

High fasting serum triacylglycerol levels may be linked to higher concentrations of fat in the liver, which in turn is strongly associated with insulin resistance. Previous studies have demonstrated that exercise is linked to reduced liver fat and improved insulin sensitivity.The authors hypothesised that taking breaks from sedentary behaviour may reduce liver fat, resulting in decreased insulin resistance and ultimately preventing T2D.

As well as the importance of the duration of sedentary periods, it has been argued that the timing of physical activity throughout the day may be a factor in metabolic health. In-vitro studies and research in animals have revealed daytime-dependent changes in exercise capacity as well as associated metabolic risk markers, however few such investigations have been performed in humans and their results are inconsistent. The team therefore aimed to investigate the associations of timing of physical activity and breaks in sedentary time with liver fat content and insulin resistance in a middle-aged population.

The researchers used data from the Netherlands Epidemiology of Obesity (NEO) study, a population-based prospective cohort study designed to investigate processes involved in the development of obesity-related diseases. Study participants were recruited between 2008 and 2012 with men and women living in the greater Leiden area being invited to participate if they were aged between 45 and 65 years and had a self-reported body mass index (BMI) of 27kg/m2 or higher. Invitations were also sent to all inhabitants aged between 45 and 65 years from one municipality within the region, as a reference population with a BMI representative of the general Netherlands population, resulting in a study population of 6,671 individuals.

Participants underwent a physical examination during which blood samples were taken to measure fasting and postprandial (after meal) blood glucose and insulin levels, while demographic, lifestyle and clinical information were obtained via questionnaire. They were also screened for suitability for an MRI scan, and roughly 35% of those able to undergo the procedure were randomly selected to have their liver fat content measured using this technique.

A further random subsample of 955 participants were given a combined accelerometer and heart rate monitor to wear for four consecutive days and nights to monitor movement and activity. Measurements of acceleration and heart rate were used to estimate physical activity energy expenditure (PAEE, measured in kJ/kg/day), which in turn allowed the team to determine time spent at different activity intensities. These were expressed as metabolic equivalents of task (MET) - a ratio of PAEE during an activity relative to that while resting (and a standard method for measuring physical activity). Sedentary periods (excluding sleep) were defined as being ≤1.5 MET, while a break in sedentary time was indicated by a spell of activity with accelerations >0.75 m/s2 (as such accelerations have been established by previous research as an accurate indicator of breaking up sedentary time). An intensity of more than 1.5 MET up to 3 MET was defined as light physical activity (LPA), with still higher intensities classed as MVPA.

The day was divided into three blocks: morning (06:00-12:00); afternoon (12:00-18:00); and evening (18:00-24:00), with the proportion of total daily MVPA occurring in each revealing the most active period. If the share of MVPA in each block differed from the others by less than 5%, then it was classified as being an even distribution of activity throughout the day.

This study is based on analysis of results obtained from those 775 participants for whom complete data sets were available. The group were 42% male and 58% female, had an average age of 56 years and average BMI of 26.2 kg/m2. After adjusting for variables such as age, sex, ethnicity and total body fat, the researchers observed that higher total PAEE and particularly MVPA were associated with both reduced liver fat content and reduced insulin resistance. An association was also found between insulin resistance and the timing of MVPA during the day: performing MVPA in the afternoon or evening was linked to reduced insulin resistance, by 18% and 25% respectively, compared to an even distribution of activity throughout the day, even after adjustment for total amount of MVPA. There was no significant difference in insulin resistance between morning activity and activity spread evenly over the day.

Neither the amount of sedentary time nor the number of breaks in sedentary behaviour were found to have any favourable association with liver fat content or insulin resistance. The authors suggest: “It could be that in our study the intensity of the activity during the breaks was too light to cause metabolic responses. Most daily activities are of light intensity and because we did not observe an association between LPA and insulin resistance, this may also explain the lack of an association between breaks and insulin resistance.”

Timing of physical activity is a relatively unexplored field in human biology and the mechanisms underlying the potential benefits of timing of physical activity remain unclear. Earlier studies have shown that metabolic responses to high-intensity exercise differed based on the time of day the exercise was performed. In addition, muscular strength as well as the metabolic function of skeletal muscle cells show a peak in the late afternoon, suggesting that being most active during this period may result in a more pronounced metabolic response than activity earlier in the day.

The researchers conclude “in addition to the total amount of daily MVPA, timing of MVPA during the day was associated with reduced insulin resistance: performing most MVPA in the afternoon or evening was associated with up to 25% reduced insulin resistance compared with an even distribution of MVPA during the day. These results suggest that timing of physical activity throughout the day is relevant for the beneficial effects of physical activity on inulin sensitivity. Further studies should assess whether timing of physical activity is indeed important for the occurrence of type 2 diabetes.”

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JOURNAL

Diabetologia

ARTICLE TITLE

Timing of physical activity in relation to liver fat content and insulin resistance

ARTICLE PUBLICATION DATE

1-Nov-2022

Poor quality sleep may be linked to heightened risk of irreversible sight loss (glaucoma)

Findings underscore need for sleep therapy in those at risk + eye checks in poor sleepers

Peer-Reviewed Publication

BMJ

Poor quality sleep, including too much or too little shut eye, daytime sleepiness, and snoring, may be linked to a heightened risk of developing irreversible sight loss (glaucoma), suggests a large UK Biobank study published in the open access journal BMJ Open.

The findings underscore the need for sleep therapy in people at high risk of the disease as well as eye checks among those with chronic sleep disorders to check for early signs of glaucoma, conclude the researchers.

Glaucoma is a leading cause of blindness and will likely affect an estimated 112 million people worldwide by 2040.  

Characterised by progressive loss of light sensitive cells in the eye and optic nerve damage, its causes and contributory factors are still poorly understood. But if left untreated, glaucoma can progress to irreversible blindness. 

While population screening may not be cost effective, targeted screening of high-risk groups might be, suggest the researchers. And previously published research suggests that sleep disorders may be an important risk factor.

To explore these issues further, the researchers set out to ascertain the risk of glaucoma among people with different sleep behaviours: insomnia; too much or too little sleep; night or morning chronotypes (‘owls’ or ‘larks’); daytime sleepiness; and snoring. 

They drew on 409,053 participants in the UK Biobank, all of whom were aged between 40 and 69 in 2006-10 when recruited, and who had provided details of their sleep behaviours.

Sleep duration was defined as normal (7 to less than 9 hours/day) and as too little or too much, outside this range. Chronotype was defined according to whether the person described themselves as more of a morning lark or night owl. 

Insomnia severity—trouble falling asleep at night or frequent waking—was classified as never/sometimes or usually, whereas subjective daytime sleepiness was categorised as never/rarely, sometimes, or frequent. 

Background information on potentially influential factors was retrieved from the questionnaires filled in at recruitment: age (average 57), sex, race/ethnicity, educational attainment, lifestyle, weight (BMI), and residential area level of deprivation.

Medical records and death registration data were used to track the health and survival of all the participants until a first diagnosis of glaucoma (hospital admission), death, emigration, or the end of the monitoring period (31 March 2021), whichever came first.

During an average monitoring period of just over 10.5 years, 8690 cases of glaucoma were identified.

Those with glaucoma tended to be older and more likely to be male, an ever smoker, and to have high blood pressure or diabetes than those who weren’t diagnosed with the disease.

With the exception of chronotype, the other four sleep patterns/behaviours were all associated with varying degrees of heightened glaucoma risk.

Short or long sleep duration was associated with an 8% heightened risk; insomnia 12%; snoring 4%; and frequent daytime sleepiness (20%).

And compared with those with a healthy sleep pattern, snorers and those who experienced daytime sleepiness were 10% more likely to have glaucoma, while insomniacs and those with a short/long sleep duration pattern were 13% more likely to have it.

The results were similar when categorised by different types of glaucoma.

This is an observational study, and as such, can’t establish cause. The study relied on self report rather than objective measurement and reflected one point in time only, acknowledge the researchers. Glaucoma might itself influence sleep patterns, rather than the other way round, they add.

But there are potentially plausible biological explanations for the associations found between sleep disturbance and glaucoma, say the researchers. 

The internal pressure of the eye, a key factor in the development of glaucoma, rises when a person is lying down and when sleep hormones are out of kilter, as occurs in insomnia, explain the researchers. 

Depression and anxiety, which often go hand in hand with insomnia, may also increase the internal eye pressure, possibly because of dysregulated cortisol production, they suggest.

Similarly, repetitive or prolonged episodes of low levels of cellular oxygen, caused by sleep apnoea (sudden stopping of breathing during sleep), might cause direct damage to the optic nerve, it has been suggested. 

“As sleep behaviours are modifiable, these findings underscore the necessity of sleep intervention for individuals at high risk of glaucoma and potential ophthalmologic screening among individuals with chronic sleep problems to help prevent glaucoma,” conclude the researchers.

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JOURNAL

BMJ Open

DOI

10.1136/bmjopen-2022-063676 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Association of sleep behaviour and pattern with the risk of glaucoma: a prospective cohort study in the UK Biobank

ARTICLE PUBLICATION DATE

1-Nov-2022