Scientists name top five foods rich in prebiotics

Eating more of these foods could benefit your gut microbiome

Reports and Proceedings

AMERICAN SOCIETY FOR NUTRITION

 

IMAGE: RESEARCHER CASSANDRA BOYD HOLDING GARLIC AND ONION, TWO FOODS THAT THE STUDY REVEALED TO BE DENSE IN PREBIOTICS. view more 

CREDIT: CASSANDRA BOYD

There is growing evidence that consuming prebiotics — certain types of fiber often found in plants that stimulate beneficial bacteria in your gut — can help to maintain a healthy gut microbiome. In a new study, scientists estimated the prebiotic content of thousands of food types by using preexisting literature to find out which foods offer the highest prebiotic content.

 

According to the study, foods that pack the greatest prebiotic punch are dandelion greens, Jerusalem artichokes, garlic, leeks, and onions. In addition to supporting gut microbes, prebiotic rich foods contain high amounts of fiber — something most Americans do not get enough of.

 

“Eating prebiotic dense foods has been indicated by previous research to benefit health,” said Cassandra Boyd, a master’s student at San José State University who conducted the research with Assistant Professor John Gieng, PhD. “Eating in a way to promote microbiome wellness while eating more fiber may be more attainable and accessible than you think.”

 

Boyd will present the findings at NUTRITION 2023, the flagship annual meeting of the American Society for Nutrition held July 22–25 in Boston.

 

Prebiotics, which can be thought of as food for the microbiome, are different from probiotics, which contain live microorganisms. Both can potentially benefit microbiome health, but they work in different ways.

 

Studies have linked higher prebiotic intake with improved blood glucose regulation, better absorption of minerals like calcium, and markers of improved digestive and immune function. Although most dietary guidelines do not currently specify a recommended daily allowance for prebiotics, the International Scientific Association for Probiotics and Prebiotics — a non-profit scientific organization that established the currently held definition of prebiotics — recommends an intake of 5 grams per day.

 

For the study, researchers used previously published scientific findings to analyze the prebiotic content of 8,690 foods contained in the Food and Nutrient Database for Dietary Studies, a resource many scientists use to study nutrition and health. 

 

About 37% of the foods in the database were found to contain prebiotics. Dandelion greens, Jerusalem artichoke, garlic, leeks, and onions had the greatest amounts, ranging from about 100-240 milligrams of prebiotics per gram of food (mg/g). Other prebiotic rich foods included onion rings, creamed onions, cowpeas, asparagus, and Kellogg's All-Bran cereal, each containing around 50-60 mg/g.

 

“The findings from our preliminary literature review suggest that onions and related foods contain multiple forms of prebiotics, leading to a larger total prebiotic content,” said Boyd. “Multiple forms of onions and related foods appear in a variety of dishes as both flavoring and main ingredients. These foods are commonly consumed by Americans and thus would be a feasible target for people to increase their prebiotic consumption.”

 

Based on the team’s findings, Boyd said a person would need to consume approximately half of a small (4-ounce) onion to get 5 grams of prebiotics.

 

Wheat-containing items rank lower on the list. Foods with little or no prebiotic content include dairy products, eggs, oils, and meats.

 

The researchers hope the study will provide a basis to help other scientists assess the health impacts of prebiotics and inform future dietary guidelines. They noted that more research is needed to understand how cooking impacts prebiotic content and to better assess foods that contain multiple ingredients.

 

Boyd will present this research at noon EDT on Saturday, July 22, during the Food Science and Nutrition Poster Session in the Hynes Convention Center Hall C (abstract; presentation details).

 

Please note that abstracts presented at NUTRITION 2023 were evaluated and selected by a committee of experts but have not generally undergone the same peer review process required for publication in a scientific journal. As such, the findings presented should be considered preliminary until a peer-reviewed publication is available.

 

About NUTRITION 2023

NUTRITION 2023 is the flagship meeting of the American Society for Nutrition and the premier educational event for nutritional professionals around the globe. NUTRITION brings together lab scientists, practicing clinicians, population health researchers, and community intervention investigators to identify solutions to today’s greatest nutrition challenges. Our audience also includes rising leaders in the field – undergraduate, graduate, and medical students. NUTRITION 2023 will be held July 22-25, 2023 in Boston. https://nutrition.org/N23 #Nutrition2023

 

About the American Society for Nutrition (ASN)

ASN is the preeminent professional organization for nutrition research scientists and clinicians around the world. Founded in 1928, the society brings together the top nutrition researchers, medical practitioners, policy makers and industry leaders to advance our knowledge and application of nutrition. ASN publishes four peer-reviewed journals and provides education and professional development opportunities to advance nutrition research, practice, and education. Since 2018, the American Society of Nutrition has presented NUTRITION, the leading global annual meeting for nutrition professionals. http://www.nutrition.org

 

Find more news briefs from NUTRITION 2023 at: https://www.eurekalert.org/newsroom/nutrition2023.

Endangered North Atlantic right whales are in 'crisis'; species approaching extinction

Emily DeLetter, 

USA TODAY
Wed, July 19, 2023 

Officials are warning that a North American species of whale is approaching extinction.

North Atlantic right whales are an endangered species in "crisis," according to a fact sheet from the NOAA Fisheries Marine Mammal and Sea Turtle Conservation Division, with fewer than 350 individuals and fewer than 70 reproductively active females remaining.

The species of whale nearly became extinct after centuries of commercial whaling, but slowly increased to almost 500 individuals in 2010 after protections from the Marine Mammal Protection Act of 1972 and the Endangered Species Act of 1973, according to the NOAA Fisheries.

Snow Cone, a 17-year-old North Atlantic right whale. The endangered species is approaching extinction, according to the NOAA.

North Atlantic right whales can be identified by white calluses on their head. They have a broad back without a dorsal fin and a long mouth that begins above the eye, according to the World Wildlife Fund. Often found in coastal waters, they can grow to be between 45-55 feet long and can weigh up to 70 tons.

Whales: Over 50 whales found dead on Scottish beach in worst mass-stranding in area, experts said

The population began declining again in 2017, and the NOAA Fisheries declared an Unusual Mortality Event for the species, which the agency defines as a "a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response."

The Unusual Mortality Event has documented 114 whales impacted since 2017: 36 have died, 33 have been seriously injured and 45 have been morbidity cases. The 114 deaths are a minimum count, according to the agency, as a majority of deaths and injuries of right whales have likely gone undetected.

The primary causes of the Universal Mortality Event for the whales are entanglements in fishing gear and vessel strikes in both U.S. and Canadian waters.

More: Largest python snake nest in Florida history discovered in Everglades

This article originally appeared on USA TODAY: North Atlantic right whales are close to extinction, NOAA says

 

This sugar kills honeybees—it could also help fight cancer

A new study helps explain the anti-cancer properties of mannose sugar

Peer-Reviewed Publication

SANFORD-BURNHAM PREBYS

 

IMAGE: HUDSON FREEZE, PH.D. view more 

CREDIT: SANFORD BURNHAM PREBYS.

LA JOLLA, CALIF. – July 18, 2023 –Research from Sanford Burnham Prebys and the Osaka International Cancer Institute has shed new light on the anti-cancer properties of mannose, a sugar that is crucial to many physiological processes in humans and is also known to inhibit the growth of cancer cells. The findings, published in the journal eLife, suggest that mannose could be a helpful secondary treatment for cancer.

“This sugar could give cancer an extra punch alongside other treatments,” says study co-author Hudson Freeze, Ph.D., director of the Human Genetics Program at Sanford Burnham Prebys. “And because mannose is found throughout the body naturally, it could improve cancer treatment without any undesirable side effects.”

Mannose is a sugar that the body adds to proteins to stabilize their structure and help them interact with other molecules. This process, called glycosylation, is essential for life; and malfunctions in glycosylation are associated with rare, but often life-threatening, human diseases.

“Until now, the most promising therapeutic use for mannose was to treat congenital disorders of glycosylation, diseases that can cause a wide range of severe symptoms throughout the body,” says Freeze. “But we believe that there may be ways to leverage mannose against cancer and other diseases as well.”

Mannose has already been shown to inhibit the growth of several types of cancer in the lab, but scientists don’t fully understand why this happens. To learn more, the research team turned their attention to an unusual property of mannose observed in an unlikely subject: honeybees. 

“It’s been known for more than a century that mannose is lethal to honeybees because they can’t process it like humans do—it’s known as ‘honeybee syndrome,’” says Freeze. “We wanted to see if there is any relationship between honeybee syndrome and the anti-cancer properties of mannose, which could lead to an entirely new approach to combat cancer.” 

Using genetically engineered human cancer cells from fibrosarcoma—a rare cancer that affects connective tissue—the research team re-created honeybee syndrome and discovered that without the enzyme needed to metabolize mannose, cells replicate slowly and are significantly more vulnerable to chemotherapy. 

“We found that triggering honeybee syndrome in these cancer cells made them unable to synthesize the building blocks of DNA and replicate normally,” says Freeze. “This helps explain the anti-cancer effects of mannose that have we’ve observed in the lab.” 

While leveraging honeybee syndrome could be a promising supplemental cancer treatment, the researchers caution that because the effect is dependent on vital metabolic processes, more research is needed to determine which types of cancer would be most vulnerable to mannose.

“If we can find cancers that have a low activity of the enzyme that processes mannose, treating them with mannose could give just enough of a nudge to make chemotherapy more effective,” says Freeze. “Many people assume that you always discover treatments in response to the disease, but sometimes you find biology that could be useful for treatment and then have to find the disease to match it.”

In the meantime, the study speaks to the broader potential of glycosylating sugars for cancer treatment, which is still an emerging area of research. 

“The glycobiology of sugar metabolism within cancer cells is still an unexplored frontier, and it could be an untapped treasure trove of potential treatments just waiting to be discovered,” adds Freeze. 

###

Additional authors on the study include Yoichiro Harada, Yu Mizote, Toru Hiratsuka, Yusuke Imagawa, Kento Maeda, Yuki Ohkawa, Shigeki Higashiyama, Hideaki Tahara and Naoyuki Taniguchi, Osaka International Cancer Institute; Takehiro Suzuki and Naoshi Dohmae, RIKEN Center for Sustainable Resource Science; Akiyoshi Hirayama, Satsuki Ikeda and Junko Murai, Keio University; Mikako Nishida and Heiichiro Udono, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; and Ayaka Ueda and Eiji Miyoshi, Osaka University. 

The study was supported by the Takeda Science Foundation, JSPS KAKENHI (JP23K06645), the Rocket Fund, and the National Institutes of Health (R01DK99551).

The study’s DOI is 10.7554/eLife.83870.

About Sanford Burnham Prebys

Sanford Burnham Prebys is an independent biomedical research institute dedicated to understanding human biology and disease and advancing scientific discoveries to profoundly impact human health. For more than 45 years, our research has produced breakthroughs in cancer, neuroscience, immunology and children’s diseases, and is anchored by our NCI-designated Cancer Center and advanced drug discovery capabilities. For more information, visit us at SBPdiscovery.org or on Facebook facebook.com/SBPdiscovery and on Twitter @SBPdiscovery.

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JOURNAL

eLife

DOI

10.7554/eLife.83870 

Termites as cause of fairy circles in Namib Desert confirmed

Peer-Reviewed Publication

MIN-FACULTY UNIVERSITÄT HAMBURG

 

IMAGE: FAIRY CIRCLES IN THE NAMIB DESERT. view more 

CREDIT: UHH/MIN/JUERGENS

For more than ten years, researchers have been discussing how the numerous circular bare patches in the middle of the African grasslands - the so-called fairy circles - can arise. In their current study "Sand termite herbivory causes Namibia's fairy circles - A response to Getzin", biologist Prof Dr Norbert Jürgens and soil scientist Dr Alexander Gröngröft from Universität Hamburg confirm that termites are the cause of the fairy circles. At the same time, they refute central arguments of the explanation put forward by ecosystem modellers that the circles are caused by self-regulation of the grasses.

As early as 2013, the Hamburg botanist Norbert Jürgens published, that purely subterranean sand termites of the genus Psammotermes cause the bare patches and, by eliminating the plants in the sandy soils, enable long-lasting storage of water after infrequent rainfall. This explanation, published in “Science”, was confirmed in the years that followed by entomologists from southern Africa (Prof Mike Picker, Dr Joh Henschel, Dr Kelly Vlieghe).

Other researchers also investigated the mysterious phenomenon, e.g. at the University of Göttingen using modelling approaches. The researchers published (Getzin et al. 2015, 2022) that the bare patches are caused by self-organisation of the grass plants, which draw water unevenly to themselves with their roots and through extensive diffusion in the sandy soils, thus causing the death of grasses in the bare patches. Furthermore, by measuring soil moisture beneath the fairy circle in 20 cm depth, they found desiccation, which they interpreted as caused fast horizontal sucking of water by the grasses of the surrounding.

Norbert Jürgens and Alexander Gröngröft now refute the central arguments of the modellers from Göttingen in the article published by PPEES: In their study, Jürgens and Gröngröft demonstrated the presence of sand termites on more than 1,700 fairy circles in Namibia, Angola and South Africa. The soil moisture measurements cited by Getzin et. al (2022) as evidence for the self-organisation hypothesis coincide with Jürgens' soil moisture measurements in 2013. However, the interpretations differ: While the modellers measure in the topsoil and interpret its drying out as withdrawal of water by the surrounding grasses, Jürgens showed in 2013 by simultaneous measurement at four different depths of up to 90 cm that the fairy circles in the subsoil store the water for a long time.

"Of even greater significance is that the analysis of my colleague Gröngröft and the measurements of the hydrological properties of the desert sand carried out in the laboratory invalidate the crucial foundations of the assumption of self-regulation," says Jürgens. "The water conductivity of the coarse-grained sand of the fairy circles, in which the termites live, is indeed very high when a lot of water is present during a heavy rain event, which can then quickly seep away in the large pores. However, the situation is completely different when the sand has released the easily movable water into the depths and has dried out to less than about eight percent of the soil volume. Then water is only stored at the points of contact between the sand grains, a continuous film of water is missing and the soil's ability to conduct water drops to very low levels. This means that at the levels of moisture found below fairy circles (≤5% by volume), very little liquid water transport can take place over short distances." The formation of dry sand layers on the soil surface directly above moist subsoil demonstrates this physical phenomenon.

"The horizontal water transports over metres in a few days assumed by the representatives of self-regulation are physically impossible according to current knowledge. The debate about opposing interpretations of a biological phenomenon is thus surprisingly decided by physics, in this case soil physics," says Jürgens.  "The soil moisture measurements on the fairy circles and the soil hydraulic properties of the sand found in the laboratory thus rule out the self-regulation hypothesis as an explanation for the fairy circles. The cause for the formation of the fairy circles is thus clear - it is the sand termites that secure a considerable survival advantage through soil moisture storage."

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JOURNAL

Perspectives in Plant Ecology Evolution and Systematics

DOI

10.1016/j.ppees.2023.125745 

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Sand termite herbivory causes Namibia´ s fairy circles – A response to Getzin et al. (2022)

 

A vegan way to stop damage from excessive ice build-up and freezer burn

Peer-Reviewed Publication

AMERICAN CHEMICAL SOCIETY

Almost everyone has a bag of veggies shoved into the dark recesses of their freezer that’s now essentially an unrecognizable block of ice crystals. And when thawed, foods damaged by excessive ice lose their texture and become mushy. Now, researchers reporting in ACS’ Journal of Agricultural and Food Chemistry have shown that broken-down soy proteins can prevent ice crystal growth and could be especially useful for preserving frozen vegan foods or biological samples.

Some animals that live in extremely cold environments, such as fish in the deep polar oceans, make antifreeze proteins to keep the liquid in their bodies from freezing. These proteins slow down ice crystal formation and growth, a process that has piqued the interest of the frozen food industry. Recently, researchers discovered that some peptides, which are pieces of broken-down proteins, can also slow ice crystal growth. However, all of the edible peptides tested so far have come from animal sources, including fish, pigs, chickens and cows. So, Tong Wang, Madison Fomich and colleagues at the University of Tennessee wanted to see if breaking down plant proteins could generate similar compounds with ice-crystal-inhibiting properties.

The team generated peptides from a commercially available soy protein isolate powder by exposing it to three different hydrolyzing enzymes: alcalase, pancreatin and trypsin. Each resulting mixture of peptides was also separated by size into multiple fractions.

All of the mixtures slowed ice growth in tests, but the ones produced from alcalase and trypsin were better inhibitors than those from pancreatin. For all three enzymes, most of the activity came from the fraction with the largest peptides. The large-size fractions also ended up including some smaller peptides, which on their own didn’t keep ice crystals from growing; however, the team showed that these small compounds boosted the activity. This study is an initial step toward using soy-derived peptides as a natural, effective way to reduce the ice growth that can lead to freezer burn and thereby increase the shelf life of frozen goods, including vegan and vegetarian products, the researchers say.

The authors acknowledge funding from the U.S. National Science Foundation and the Hatch/Multistate Project through the U.S. Department of Agriculture.

The paper’s abstract will be available on July 19 at 8 a.m. Eastern time here: http://pubs.acs.org/doi/abs/10.1021/acs.jafc.2c08701

For more of the latest research news, register for our upcoming meeting, ACS Fall 2023. Journalists and public information officers are encouraged to apply for complimentary press registration by completing this form.

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

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JOURNAL

Journal of Agricultural and Food Chemistry

DOI

10.1021/acs.jafc.2c08701 

ARTICLE TITLE

Ice Recrystallization Inhibition Activity of Soy Protein Hydrolysates

ARTICLE PUBLICATION DATE

19-Jul-2023

 

Melatonin doesn’t just help you sleep — it can help keep fruit and vegetables fresh

The natural compound can be used to reduce the amount of fresh horticultural produce lost due to ‘chilling injury’.

Peer-Reviewed Publication

EDITH COWAN UNIVERSITY

Edith Cowan University (ECU) horticultural scientists have been compiling research over the past year from all over the world to assess the benefits of melatonin application onto fruit and vegetables, to help keep these highly perishable foods fresher – for longer.

 

Lead researcher Professor Zora Singh said up to 44 percent of fresh horticultural produce is lost from farm to consumption, and ‘chilling injury’ plays a key role in the postharvest losses.

 

“You will often see abnormal ripening, sunken spots, pitting, hardening of flesh and browning of peel and pulp in cold-stored fruits, while browning of tissues, translucency and water-soaked lesions in the vegetables, that is what we call chilling injury,” Professor Singh explained.

 

“The average storage temperature for subtropical fruits and vegetables usually range from 4–8°C while 10–20°C is optimum temperature to avoid chilling injury in tropical horticultural produce.”

 

Professor Singh and his team claim most of the evidence points to melatonin as one of the best ways to prevent or reduce the effects of chilling injury to cold-stored fruit and vegetables.

 

“Melatonin is a natural sleeping hormone in living organisms, and it is also helpful in reducing chilling injury symptoms and membrane leakage by maintaining higher levels of antioxidants and freshness of horticultural produce,” researcher and PhD student Shoaib Shah explained.

 

“Melatonin is a safe alternative to hazardous chemical treatments, without any adverse effects on the consumer health.”

 

Global food security – the challenge    

 

Across the globe food security is an escalating problem, with food losses rising annually.

 

• 13.2 per cent of food, valued at $400 billion, is lost annually between harvest and the retail market (FAO 2019)
• 17 per cent of food production is wasted in households, food services and in retail (UNEP 2020)
• Food loss and waste account for approximately 8-10 per cent of global greenhouse gas (GHG) emissions (UNEP 2021)

 

Fresh produce, such a fruit production is declining, the result of shrinking agricultural land, reduced availability of water supplies, climate change and soil degradation.

 

Chilling injury is another significant factor contributing to that decline, resulting in 44 per cent of fruit and vegetables not being fit for human consumption globally.

 

Tropical and sub-tropical fruits are most at risk, as they are highly perishable.

 

While fruits such as apples can stored for up to nine months, berries can only be kept refrigerated for seven to 12 days.

 

“When it comes to grains and other produce for harvest, they are more resilient than fresh horticultural produce,” Professor Singh said.

 

“Fruit and vegetables are not only challenging to grow, preserving them is immensely difficult and this is a crisis affecting nations all over the world, so we need to find the solution to keep producing food from the earth in a sustainable way.”

 

Professor Zora Singh is a Foundation Professor of Horticultural Science in ECU’s School of Science with global research expertise in production technology and postharvest physiology of horticultural crops.

 

Presently, Professor Singh and his research team, including PhD students, are working to minimise the global food and nutritional security challenges by improving production technology and reducing postharvest losses in fresh horticultural produce - from farm to fork.

 

You can read the full paper, Insight into the Role of Melatonin in Mitigating Chilling Injury and Maintaining the Quality of Cold-Stored Fruits and Vegetables authored by Shoaib Shah, Zora Singh, Eben Afrifa-Yamoah, Mahmood UI Hasan, Jashanpreet Kaur and Professor Andrew Woodward here.

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JOURNAL

Food Reviews International

DOI

10.1080/87559129.2023.2212042 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Insight into the Role of Melatonin in Mitigating Chilling Injury and Maintaining the Quality of Cold-Stored Fruits and Vegetables

 

Evaluation of the applicability of multiple drought indices in the core zone of “westerlies-dominated climatic regime”

Peer-Reviewed Publication

SCIENCE CHINA PRESS

 

IMAGE: IN THE 5 SUBGRAPHS ON THE LEFT, SPATIAL DISTRIBUTION CHARACTERISTICS OF ANNUAL AND SEASONAL VARIATIONS OF PRECIPITATION (PRE) DURING 1961–2014. IN THE 5 SUBGRAPHS IN THE CENTER, SPATIAL DISTRIBUTION CHARACTERISTICS OF ANNUAL AND SEASONAL VARIATIONS OF POTENTIAL EVAPOTRANSPIRATION (PET) DURING 1961–2014. IN THE 5 SUBGRAPHS ON THE RIGHT, SPATIAL DISTRIBUTION CHARACTERISTICS OF ANNUAL AND SEASONAL VARIATIONS OF SOIL MOISTURE IN WHOLE LAYER (SM) DURING 1980–2014. view more 

CREDIT: ©SCIENCE CHINA PRESS

With the intensification of global warming, different regions are facing constantly changing hydroclimatic conditions, which brings significant uncertainties to the assessment of dry-wet under the backdrop of global warming and the study of drought events. The core zone of “westerlies-dominated climatic regime” primarily includes the five Central Asian countries and China's Xinjiang, located in the heartland of the Eurasian continent and dominated by westerly circulation. Its climate and hydrological changes differ from monsoon regions and have received widespread attention in recent years. As a key indicator for measuring the variation of dry-wet trend and the change of drought events, the applicability of drought indices also varies across different regions. Therefore, selecting the most suitable index to reflect the changes in aridity and characteristics of drought events in that region forms the basis for unraveling and revealing the hydroclimatic change facts and mechanisms.

To address the above challenges, Professor Wei Huang’s research group at Lanzhou University evaluated the ability of three indices: the Standardized Precipitation Evapotranspiration Index (SPEI), the Standardized Moisture Anomaly Index (SZI), and the self-calibrating Palmer Drought Severity Index (scPDSI) to describe the dry-wet characteristics and drought events in the core zone of the “westerlies dominated climatic regime” from multiple dimensions such as climate, hydrology, and vegetation.

The research findings revealed important insights into the dry-wet trends and drought events in the study area. Over the past 60 years, Kazakhstan had experienced uniform drying, while the four southern Central Asian countries had witnessed drier conditions in the western parts and wetter conditions in the eastern parts. This aligned with the observed slight increase in precipitation in Kazakhstan and the four southern Central Asian countries, accompanied by a significant rise in potential evapotranspiration, ultimately leading to drier conditions. In Xinjiang, the hydroclimatic variables, SZI and scPDSI indicated a trend towards increased humidity, particularly in summer. However, the SPEI demonstrated an opposite pattern of change. (see Figures 1 and 2). The researchers noted that the SPEI, being more sensitive to potential evapotranspiration alterations, exacerbated the severity of regional drought in arid and semi-arid regions due to rising temperatures. Consequently, it is not applicable to the study of drought in the core zone of the “westerlies-dominated climatic regime.”

The team also evaluated the capability of the index to identify different degrees of drought events in the study area. The SZI employed a standardization approach based on a nonlinear three-parameter probability cumulative distribution function to enhance the representation of drought conditions. However, actual climate change often deviates from the normal distribution, leading to the underestimation of severe and extreme drought events by SZI. On the other hand, the scPDSI primarily focused on assessing the severity of regional drought to provide a better reflection of the overall drought situation in the area. As a result, it could effectively reproduce the occurrence of drought events in most parts of Xinjiang during the corresponding period (see Figure 3). In summary, the scPDSI is better suited for monitoring and identifying the characteristics of drought, including extreme drought events, in the core zone of the “westerlies-dominated climatic regime”.

These research findings provide a valuable theoretical foundation for the utilization and improvement of drought indices, as well as the monitoring, attribution, and prediction of drought events in arid areas. They will significantly contribute to the estimation and understanding of climate and environmental risks in the future, as the impacts of human activities continue to increase in arid regions.

See the article:

Guo H, Huang W, Xie T, Ma S. 2023. Evaluation of the applicability of multiple drought indices in the core zone of “westerlies-dominated climatic regime”. Science China Earth Sciences, 66(7): 1504–1520, https://doi.org/10.1007/s11430-022-1097-0

In the five subgraphs on the left, spatial distribution characteristics of annual and seasonal variations of scPDSI. In the five subgraphs in the center, spatial distribution characteristics of annual and seasonal variations of SZI. In the five subgraphs on the right, spatial distribution characteristics of annual and seasonal variations of SPEI.

The two subgraphs above (a) and (b), the severe drought in 1989. The two subgraphs below (c) and (d), the continuous drought in spring and summer in 2008.

CREDIT

©Science China Press

JOURNAL

Science China Earth Sciences

DOI

10.1007/s11430-022-1097-0 

DINOSAURS/FOSSILS

Flying reptiles had nurturing parental style, new research finds

Peer-Reviewed Publication

UNIVERSITY COLLEGE CORK

 

IMAGE: YANG ET AL. (2023) SHOW THAT LARGE-BODIED PTEROSAURS, SUCH AS THE GIANT PTERANODON (SHOWN HERE), PROBABLY PRACTICED PARENTAL CARE. UNLIKE SMALL PTEROSAURS, WHICH WERE BORN WITH WELL-DEVELOPED WINGS AND COULD FLY SOON AFTER HATCHING, LARGE PTEROSAURS WERE BORN WITH SMALL ARMS THAT WOULD NOT HAVE FACILITATED ACTIVE POWERED FLIGHT, AND PARENTAL CARE WOULD HAVE BEEN ESSENTIAL TO SURVIVAL OF THE YOUNG AND ENABLING THEM TO GROW TO HUGE SIZES. ARTWORK BY JAMES ROBINS. view more 

CREDIT: JAMES ROBINS/UCC

•

    Flying pterosaurs were caring parents – but only larger species.
•    Research led by University College Cork finds parental care behaviour changed with evolution.
•    International team involved researchers based in Ireland, China, and the UK.

Did the pterosaurs, flying reptiles from the days of the dinosaurs, practice parental care or not? New research by scientists from Ireland (University College Cork), China (Nanjing and Yunnan Universities) and the UK (University of Bristol and Queen Mary University of London) shows that pterosaurs were indeed caring parents – but only the larger species.

This solves a long-standing conundrum. To be able to fly soon after hatching from the egg, a bird or pterosaur must have well-developed wings. Studies of smaller pterosaurs from the Jurassic showed that their babies already had large wings when they hatched and they could have wobbled into flight within a few days of birth.

But did this work for the later pterosaurs which were much larger in size? In the Cretaceous, pterosaurs usually had wingspans of 5 metres, and some even reached 10–15 metres, the size of a small glider.

“This was a difficult project,” says the study leader, Dr Zixiao Yang from University College Cork (UCC). ‘We needed examples of pterosaurs where we had at least one hatchling or very young specimen as well as adults so we could study their growth rates. But baby pterosaurs are really rare.”

Dr Yang collaborated with Professor Baoyu Jiang from Nanjing University, Professor Michael Benton of University of Bristol, Professor Xu Xing of Yunnan University, and Professor Maria McNamara of UCC on the research.

“Luckily, we were able to use some classic specimens from the Jurassic of Europe and the Cretaceous of North America, together with new finds from China. By measuring the skulls, backbones, wings, and hind legs, we were able to test for differences in the relative growth of different parts of the body.”

The research focussed on testing the allometry, or how the creatures’ characteristics changed with size.

“We are all familiar with allometry in human babies, puppies and kittens – their heads, eyes and knees are huge, and the rest of the body grows faster to get to adult proportions. It’s the same with many animals, including dinosaurs and pterosaurs. The babies have cute faces, with short noses, big eyes, and big heads,” Dr Yang said.

“The small, bird-sized, Jurassic pterosaurs were born with large wings and strong arms and legs, evidence that the babies could fly from birth. As they grew from baby to adult, their arms and legs showed negative allometry, meaning they started large and were then growing more slowly than the rest of the body.”

“But it was different for the Cretaceous giants. They also started as small babies, but the key limb bones show positive allometry through growth, suggesting a very different developmental model.”

“This means that the pterosaur giants had sacrificed low-input childcare to the need to grow huge eventually as adults. Minimal childcare makes sense in the early evolutionary history of these ancient reptiles because it saves energy. But to grow huge, the larger pterosaurs had a problem – it basically took much longer to become an adult, and therefore parents needed to protect their young from accidents. The babies of all pterosaurs, large and small, were small because of the limitations of egg size. Investing in childcare by having non-flying babies was offset in evolutionary terms by allowing pterosaurs to evolve truly huge sizes.”

“We see the same thing in birds and mammals today. Some birds fly very young, and of course some mammals like cattle and antelopes are on their feet the day they are born. But this kind of behaviour is risky for the babies because they are often clumsy and are easy targets for predators; it’s costly also for the mother because the babies must have highly developed wings or legs at the point of birth. So, we see the same thing in extinct pterosaurs. They were restricted in maximum body size until the end of the Jurassic, at which point their parental care behaviour changed, and then they could achieve huge sizes.”

The paper ‘Allometric wing growth links parental care to pterosaur giantism’ is published in the journal Proceedings of the Royal Society B.

ENDS

: Yang et al. (2023) show different growth patterns in large and small pterosaurs. The wings of small-bodied pterosaurs show bones that grew slowly with respect to the rest of the body, indicating that they were already good fliers soon after hatching. Large-bodied pterosaur species, however, were born with small arms. Even though their wing bones grew quickly after hatching relative to the rest of the body, the young of these species could not fly efficiently and therefore high-input parental care was critical to survival.

CREDIT

UCC

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JOURNAL

Proceedings of the Royal Society B Biological Sciences

DOI

10.1098/rspb.2023.1067 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Allometric wing growth links parental care to pterosaur giantism

ARTICLE PUBLICATION DATE

19-Jul-2023