Among African children admitted to 25 hospitals with COVID-19 between March and December 2020, infants younger than 1 year had nearly five times the risk of death than adolescents aged 15 to 19 years. Children of all ages with comorbidities, including high blood pressure, chronic lung diseases, hematological disorders and cancer, also were at higher risk of dying.

“Although our study looked at data from earlier in the pandemic, the situation hasn’t changed much for the children of Africa — if anything, it is expected to be worsening with the global emergence of the highly contagious Omicron variant,” said lead author Jean B. Nachega, M.D., Ph.D., M.P.H., associate professor of infectious diseases and microbiology and epidemiology at Pitt’s Graduate School of Public Health. “Vaccines are not yet widely available, and pediatric intensive care is not easily accessible.”

The study examined outcomes in 469 children who ranged in age from 3 months to 19 years and were hospitalized in one of six countries: the Democratic Republic of the Congo, Ghana, Kenya, Nigeria, South Africa and Uganda. A quarter of the children had pre-existing conditions. Eighteen had confirmed or suspected multisystem inflammatory syndrome, a serious complication of COVID-19 where different parts of the body become inflamed.

The study, which included investigators across all six of the African countries that provided data, found that 34.6% of hospitalized children were admitted to an intensive care unit (ICU) or required supplemental oxygen, and 21.2% of those admitted to the ICU required invasive mechanical ventilation. During the time frame studied, 39 — over 8% — of the children died. This compares with rates between 1% and 5% that have been reported in high-income countries.

“The high morbidity and mortality associated with hospitalized children with COVID-19 in our study challenge the existing understanding of COVID-19 as a mild disease in this population,” said Nachega, also a professor extraordinary of medicine at Stellenbosch University’s Faculty of Medicine and Health Sciences in Cape Town, South Africa. “But if a child has a comorbidity, is very young and is in a place where there are limited or no specialized doctors, facilities or equipment for pediatric intensive care, then that child faces a very real possibility of dying.”

“Our findings call for an urgent scale-up of COVID-19 vaccination and therapeutic interventions among at-risk eligible children and adolescents in Africa,” Nachega continued. “They also raise further the acute need for capacity-building and support for pediatric intensive care in these settings.”

Nachega noted recent progress on increasing the COVID-19 vaccine supply in Africa but emphasized that those vaccines are not yet widely available and only about 5% of the continent’s population has been fully vaccinated.

“COVID-19 vaccine hesitancy is a global issue, and Africa is no exception,” he said. “It is imperative that evidence-based public health campaigns address concerns in accessible, trustworthy ways so that there is high vaccine uptake as soon as it is available.”

Additional investigators of this study are members of the African Forum for Research and Education in Health COVID-19 Research Collaboration on Children and Adolescents and are listed in the JAMA Pediatrics article.

This research was supported by National Institutes of Health Fogarty International Center grant 1R25TW011217-01.

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The study, which examined zebrafish embryos, discovered a type of astrocyte glial cell that is new to science, and have been named estrogen responsive olfactory bulb (EROB) cells.

estrogens are known for their roles as signalling hormones in the development of sex, but the study shows that prior to sexual differentiation (when the sex of an individual becomes fixed), a small group of cells in the region of the brain where the sense of smell develops, the olfactory bulb, are responsive to estrogen.

The research, led by Dr Aya Takesono of the University of Exeter, employed a genetically engineered (transgenic) zebrafish, developed in the laboratories of Professor Tyler and Dr Kudoh at Exeter, that enables cells and tissues responding to estrogen to be seen via microscopy imaging for this work.

Using this transgenic zebrafish, together with chemical and genetic methods to manipulate these estrogen responding cells, has revealed a new function of estrogens during embryonic brain development.

Dr Takesono said: “Previous studies in mice have shown that estrogen is important for development of the somatosensory cortex of the brain and for establishing sexual dimorphic brain tissues that mediate reproductive functions and behaviour in later life.

“In this study, however, we show that the olfactory bulb is the one of earliest parts of the developing brain that is responsive to estrogens in the zebrafish embryo.

“We further show that our newly discovered EROB cells mediate the estrogen driven instruction for development of olfactory sensory system in the embryonic brain.”

Tracing the development of these EROBs using various cellular and imaging methods showed they interact with olfactory sensory neurons and their loss — or disturbance of their interactions with the surrounding neurons — disrupts establishing inhibitory neural connections in the olfactory glomeruli.

Using another transgenic zebrafish, this time one that detects both neural activity (via the detection of calcium produced when nerve cells fire) and estrogen responses, the study shows that estrogen signalling alters neuronal activity in the olfactory bulb through these newly identified EROBs which in turn affects odorant-response behaviour.

This study provides evidence that estrogens act on EROB glia to regulate olfactory circuits with important consequences for the sense of smell in later life.

Professor Tyler, senior author in the work, said: “This work identifying new embryonic brain cells involved in the development of the sense of smell in fish opens up a major new research area for us.

“Surface waters receive many human-made chemicals that mimic estrogens and an intriguing question we wish to now address is whether these chemicals affect the function of the EROB glia in embryogenesis and thus alter the sense of smell, as this could have major fitness consequences for fish.”

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According to the study, published in the journal Proceedings of the Royal Society B, coral populations of the Mediterranean — essential for the functioning of the coral reefs, one of the most emblematic habitats in this sea — could be unable to recover from the recurrent impact of these extreme episodes, with water temperatures reaching high degrees for days and even weeks.

This is the first study to assess the long-term recovery capacity of populations of two emblematic species of Mediterranean coral: the red gorgonian (Paramuricea clavata) and the red coral (Corallium rubrum), which provide complex habitats that are essential for a great diversity of associated fauna. Therefore, it is essential to understand their resilience regarding the more frequent and intense heatwaves.

Mass mortality events

The climate crisis is severely affecting the marine ecosystems worldwide, and the Mediterranean is no exception. In particular, the marine heatwaves associated to the climate crisis are causing mass mortality events in all the coastal ecosystems of this basin, and among the most affected species are the Mediterranean corals.

Knowledge on the coral’s long-term resilience is still scarce, despite the studies that analysed the immediate impact of marine heatwaves on these organisms. These are long-lived species (more than a hundred years in some cases) and with slow populational dynamics (that is, organisms with low growth and recruitment rates), and therefore researchers need long temporary series (decades) to assess their recovery capacity.

As part of the study, the team analysed the results obtained in a long-term monitoring on different populations of coral affected by a great mass mortality caused by a heatwave in 2003 in the protected marine area of Scandola (Corsega, France). In particular, they analysed data on the state of these populations (density, size structure and biomass) collected during the following fifteen years to the heatwave, by the researchers of the MedRecover research group, formed by experts of the UB and ICM-CSIC, among other centres.

Far from recovery, the results show that all the analysed populations tended to collapse since they were affected by the 2003 heatwave. Fifteen years after this event, these populations are practically considered to be extinct from a functional perspective.

“We observed an average biomass loss regarding the initial biomass of 80% in populations of red gorgonian, and up to a 93% regarding the studied population of red coral,” notes Daniel Gómez, researcher at ICM-CSIC.

“These data are worrying for the conservation of these emblematic species, and it indicates that the effects of the climate crisis are speeding up with obvious consequences for the submarine landscapes, where the loss of coral equals the loss of trees in forests,” notes Joaquim Garrabou, also member of ICM-CSIC.

Recurrent exposure to heatwaves

Cristina Linares, professor at the Department of Evolutionary Biology, Ecology and Environmental Sciences of the Faculty of Biology and member of IRBio, says that “we believe one of the main reasons why we observed these collapse trajectories is the potential recurrent exposure to heatwaves, incompatible with the slow populational dynamics of these species.” In particular, during the study period (2003-2018), they registered important heatwaves in at least four years: 2009, 2016, 2017, 2018.

“During these heatwaves,” continues Linares, “the temperature conditions in the studied area reached extreme levels which are incompatible with the life of these corals, which probably caused new mortality events to the decimated populations and made the recovery impossible.”

Since we expect the number and intensity of marine heatwaves to increase over the following decades due to the climate crisis, the viability of many coral populations could be seriously threatened.

“However, there will probably be some areas in the Mediterranean in which, due to several factors, the recurrence of such climate impacts may be lower. This makes it especially relevant to keep — regarding other potential impacts — these climate refuges where the trajectories of coral populations could be more positive than those observed in this study,” notes the research team.

“Nevertheless, there is an urgent need for stronger measures to be implemented against the climate crisis before the loss of biodiversity becomes irreplaceable,” conclude the experts.

This study has been carried out thanks to the support of the Regional Natural Park of Corsica, the HEATMED National Plan project (RTI2018-095346-B-485 I00), the European projects H2020, MERCES, H2020 Futurmares, Interreg MED MPA-Engage and Interreg MED MPA-Adapt.

Now, she is a climate scientist and associate research professor of dendrochronology in the University of Arizona Laboratory of Tree-Ring Research. And she is trying to understand how a warming world is transforming the place she once called home.

Someday, the Arctic Ocean may no longer host ice, since the northern regions of the world are warming are faster than the rest — a trend scientists refer to as Arctic amplification. As Arctic ice melts, new opportunities and challenges for humans will arise, researchers say.

Freshwater flowing into the Arctic Ocean from the continent is thought to exacerbate Arctic amplification, but the extent of its impact isn’t fully understood. New research led by Panyushkina measures how the flow of the Yenisei River — the largest freshwater river that flows into the Arctic Ocean — has changed over the last few hundred years, and describes the impact freshwater has had on the Arctic.

Previous studies have attributed recent changes in wintertime freshwater flow into the Arctic to warming air temperature, seasonal precipitation changes or snowpack. But more recent research, including Panyushkina’s study, suggests that the primary driver is actually degradation of permafrost — or frozen ground — as well as forest fires across southern Siberia.

Panyushkina’s research, funded by the National Science Foundation Polar Office, is published in the journal Environmental Research Letters.

What trees can tell us

Data collected by instruments at the upper reaches of the Yenisei River in Tuva, in southern Siberia, only goes back so far. To overcome this, Panyushkina and her team used tree-ring data to double the number of years’ worth of the stream flow data they had, allowing them to look back 300 years.

Stream flow, or the amount of water that moves through a certain area of a river over time, can be inferred by measuring changing tree-ring thickness over the years. Measurements of stream flow over specific seasons can even be teased out of the data.

Annual stream flow information is commonly used by water managers to reveal the average changes in stream flow trends. But Panyushkina and her team did something novel when they decided to also investigate winter stream flow specifically.

“We found an unprecedented increase in the winter flow rate over the last 25 years,” Panyushkina said. This winter flow rate is nearly 80% above the average seen over approximately 100 years.

“In contrast, annual flow fluctuated normally during the 300-year period, with only a 7% increase over the last 25 years,” Panyushkina said.

The winter stream flow data revealed the role of permafrost melt on Arctic ice.

Since ice covers rivers during winter in Siberia, the team’s stream flow measurements only captured information about river waterthat originated underground rather thanfrom the sky. That includes water from thawing permafrost, as well as water from sub-permafrost aquifers, as permafrost loss leads to an increased exchange of water between the river and aquifers. These two sources of groundwater are warm compared to the frigid air above, and when they eventually flow into the Arctic Ocean, they melt the ice.

An uncertain future

Forest fires are also thought to be a driver of Arctic ice melt.

“We know the frequency and intensity of forest fires in Siberia have been increasing,” Panyushkina said. “When fires happen in forests with permafrost, there is deep thawing under the fire event, and the affected area often doesn’t recover for up to 60 years. When we have large-scale fires and long-burning fires and more frequent fires, we’re maybe hitting the critical point when permafrost degradation cannot return to normal. Forest fires are also another process that increases connectivity between aquifers and stream flow.”

The combined effects of permafrost degradation and fires are very strong at the Yenisei River basin, with more fresh water and heat flowing into the Arctic Ocean in recent decades, according to the study. In turn, melting sea ice also exacerbates global warming.

“Research interest in the region is booming because the surface temperature is warming much faster here than anywhere else in the world,” Panyushkina said. “It’s a hot spot for climate research, and because I grew up there and understand how the system works, it’s a natural topic of study for me. I’m also very interested in knowing the impact of an ice-free Arctic on the surrounding landscape. Humans have never seen an ice-free Arctic before, ever. My mind still cannot comprehend how the Arctic Ocean can be free of ice.”

By the middle of the century, changing sea ice conditions are expected to lead to greater navigability for open water-vessels crossing the Arctic. A future trans-Arctic shipping route called the Supra Polar Route will link the Atlantic and Pacific Oceans through the Arctic, potentially paving the way for more trans-Arctic commerce.

There is a need to quantify the Arctic amplification impacts to manage and regulate Arctic seas of the future, Panyushkina said.

“This strong prospect of the global trade fleet entering the Arctic opens the Pandora’s box of near-future geopolitical and environmental issues and reinforces the urgency for a new regulatory framework by international organizations to ensure adequate environmental protections and vessel safety standards,” she said.

To understand more about Arctic amplification and its consequences, Panyushkina and her team plan to study other rivers in Siberia.

“There are two more Siberian rivers similar in size to the Yenisei,” she said. “If we can quantify the stream flow from those rivers, we’ll have more precise and clear understanding of its impact on the Arctic.”

The study of the mineral and macronutrient composition of huhu grubs (Prionoplus reticularis larvae) was undertaken by Food Science PhD student Ruchita Rao Kavle and the results have recently been published in the International Journal of Food Science and Technology.

Miss Rao Kavle says the analysis found huhu grubs had a high fat content — for which they have traditionally been known — but it was the high levels of protein that really stood out.

“Across the four development stages of the huhu, protein ranged from 26.2 per cent to 30.5 per cent, which is high when compared to other common protein sources such as beef (21 per cent), lamb (20.3 per cent), chicken (17.4 per cent), soy (13 per cent), and chickpeas (20.5 per cent).

“We also found that the grubs were rich in essential minerals which all play vital roles in human health and nutrition, the most abundant been manganese, magnesium, phosphorus, iron, copper, and zinc,” she says.

The analysis was undertaken on wild huhu grubs during four different development stages of their life cycle, and which were harvested from a pine-forested site in Dunedin.

Miss Rao Kavle says based on the results, a person weighing 60kg would require around 170g of huhu, or about 75 huhu grubs, to meet the same daily protein requirement that could be sourced from 230g of beef.

“Compared to beef, a smaller amount of huhu needs to be consumed, but some people would find eating 75 grubs off-putting.”

Miss Rao Kavle’s research is also looking into options to process the grubs into more presentable forms such as flour and meals.

Study supervisor and co-author Dr Dominic Agyei says this pioneering study brings scientific evidence to highlight the nutritional value of the traditional food source.

He says that even though huhu grubs have not been accessible commercially in New Zealand, there is an ever-growing interest in sustainability in food production, alternative proteins, and the need to diversify food sources.

“A focus on indigenous foods, particularly their unique nutritional and health properties, and alternative proteins is surging. This study on the huhu comes on the back of other research we have also undertaken on the larvae of several edible insects such as mealworms and black soldier flies,” Dr Agyei says.

The research concluded that New Zealand wild-harvested huhu is nutritious and safe for consumption, however the authors point out that as with most foods, moderate consumption is recommended, and the importance of variety and balanced diets cannot be overruled.

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