In new research published in Nature Communications, co-authors Andrew J. Conith, postdoctoral researcher in the UMass Amherst biology department, and Craig Albertson, professor of biology at UMass Amherst, focus on the jaws of cichlids — which are notable because they have two sets of them.

“Remember the movie ‘Alien,'” asks Conith, “when the alien is about to eat Sigourney Weaver’s character? It opens its mouth and out comes a second set of jaws. Fast forward twenty years, and here I am, studying animals that have jaws in their throats.”

Cichlids, thankfully, don’t eat humans, but, thanks to their twin pairs of jaws, they are a phenomenally successful group of fishes from an evolutionary standpoint. In Lake Malawi alone, more than 1,000 different species of cichlids have evolved over the last 1 to 2 million years. One set of jaws, the oral jaw, is similar to our own, and its role is to capture food. But cichlids, like the Xenomorph from ‘Alien,’ have a second set of jaws, deeper in their throats, that’s made to process food once it has been captured by the first set. Having two pairs of jaws means that each jaw can specialize in a specific role, a feature that should increase their feeding efficiency and make them more evolutionarily successful.

Given the success of cichlids, understanding the evolution of these two jaws has become an important line of inquiry for biologists. “We’re trying to gain a better understanding of the origins and maintenance of biodiversity,” says Albertson. Researchers have long thought that the two sets of jaws are evolutionarily decoupled and can evolve independently of one another, pushing the boundaries of morphological evolution. However, Conith and Albertson demonstrated that such decoupling does not appear to be the case for cichlids, challenging a quarter-century-old assumption. “What we’ve found is not just that the evolution of the two sets of jaws is linked, but that they’re linked across multiple levels, from genetic to evolutionary,” says Albertson

These findings are a significant step forward in better understanding how evolution works. For instance, many models of evolution theorize both that organisms are constructed from repeated units — digits on your hand or teeth in your mouth — and that these individual units evolve independently from one another. “It is this ‘modularity’ of organisms that is thought to facilitate the evolutionary process,” Albertson notes.

Linked systems are usually thought to lack evolutionary potential. “They just cannot evolve in as many dimensions,” Conith says. This is referred to as an evolutionary constraint, and it plays an important role in shaping biodiversity. Constraints determine what body structures are possible.

Remarkably, this constraint seems to be the key to cichlid’s success by promoting rapid shifts in jaw shapes and feeding ecology, all of which is likely to be an advantage in a dynamic and fluctuating environment, like the East African Rift Valley, where Lake Malawi is located. “The constraint is actually facilitating cichlid evolution, rather than impeding it,” says Conith.

“This tells us that we need to rethink the fundamentals of evolutionary mechanisms,” says Albertson. “Perhaps constraints play a wider role in the evolutionary success of species around the world.”

Five peer-reviewed papers in the journal Nature highlight the opportunities to leverage the vast diversity of aquatic, or “blue,” foods in the coming decades to address malnutrition, lower the environmental footprint of the food system, and provide livelihoods.

“People are trying to make more informed choices about the food they eat, in particular the environmental footprint of their food,” said Ben Halpern, a marine ecologist at UC Santa Barbara’s Bren School of Environmental Science & Management, who with colleagues examined the environmental sustainability of aquatic foods, the potential for the growth of small-scale producers and the climate risks that face aquatic food systems. “For the first time we pulled together data from hundreds of studies on a wide range of seafood species to help answer that question. Blue foods stack up really well overall and provide a great option for sustainable food.”

The research projects that global demand for blue foods will roughly double by 2050, and will be met primarily through increased aquaculture production rather than by capture fisheries.

Investing in innovation and improving fisheries management could increase consumption even more and have profound effects on malnutrition. For instance, a “high growth” modeling scenario showed that increasing supply by 15.5 million tons (8%), causing a drop in prices, would reduce cases of nutrient deficiencies by 166 million, especially among low-income populations.

“Small-scale fishers — the individuals and small boats that fish in places all around the world — are a huge part of the global seafood system and are incredibly diverse in who they are and how they fish,” said Halpern, who also directs the National Center for Ecological Analysis & Synthesis at UCSB. “That diversity creates both opportunities and challenges for sustainably managing the oceans. We unpacked this diversity to help guide better management.”

Blue foods were found to rank more highly than terrestrial animal-source foods in terms of their nutritional benefits and potential for sustainability gains.

Many blue food species are rich in important nutrients. Compared to chicken, trout has approximately 19 times more omega-3 fatty acids; oysters and mussels have 76 times more vitamin B-12 and five times more iron; and carps have nine times more calcium.

“For the first time we got to see what more aquatic food production would mean for human health globally,” said Bren School marine ecologist and assistant researcher Christopher Free, who with fellow UCSB marine scientist Jacob Eurich co-authored a study that examines the nutritional potential of blue foods. “What we project is that by making aquatic foods cheaper to the consumer, there’s likely going to be a shift away from land-based foods like chicken, beef and dairy. I think what made us really excited is knowing that aquatic food could be a useful solution to combating malnutrition, and really showing that comprehensively for the first time.”

The nutritional benefits of blue foods are especially important for women, who were found to benefit more than men from increased consumption in nearly three times the number of countries studied.

On average, the major species produced in aquaculture, such as tilapia, salmon, catfish and carp, were found to have environmental footprints comparable to chicken, the lowest-impact terrestrial meat. Small pelagic species like sardines and anchovies, bivalves and seaweeds all already offer lower stressors than chicken.

Further investments to improve the sector’s efficiency and reduce its environmental footprint can have sector-wide benefits, including for less commonly raised species like European bass, weakfish, flatfish, sea breams and milkfish.

The research found that blue food systems facing the highest risk from climate change are also typically located in those regions where people rely on them most and where they are least equipped to respond and adapt to climate hazards.

“Climate change is creating all sorts of risks to humanity, including to our food,” Halpern said. “Blue foods are no different and in fact face some unique risks from things like acidifying and warming waters. But not all foods are equally vulnerable to these risks — in our work we show where, how and why different blue foods face different risks from climate change.”

These five papers are the first in a series produced by the Blue Food Assessment (BFA), a group of more than 100 leading researchers led by Stanford University’s Center for Ocean Solutions & Center on Food Security and the Environment, the Stockholm Resilience Centre at Stockholm University and EAT.

“Blue foods are much more diverse than typically thought, and so too are the many communities of small-scale fishers who are often overlooked despite providing the majority of blue food people eat,” said Beatrice Crona, co-chair of the BFA and deputy science director at the Stockholm Resilience Centre.

“Few, if any, countries are developing their blue food sector to provide ecological, economic, and health benefits to its full potential,” said Rosamond Naylor, BFA co-chair and founding director of the Center on Food Security and the Environment at Stanford University. “This assessment aims to provide the scientific foundation for decision-makers to evaluate trade-offs and implement solutions that will make blue foods an instrumental part of an improved food system from local to global scales.”

“The BFA assessment emphasizes the enormous diversity of blue foods, all of which carry important nutritional, cultural, economic and environmental value,” said Fabrice DeClerck, EAT science director. “To realize its potential, policymakers should put in place better governance, including participation of small producers, women and other marginalized groups, better stewardship of the natural resources on which blue foods rely; and investment in building resilience to climate change.”

“We are nine fishing seasons away from the deadline for achieving the 2030 Sustainable Development Goals so the urgency is high,” said Jim Leape,co-director of the Stanford Center for Ocean Solutions. “This research can help policymakers, companies, financiers, fishers and consumers capitalize on the immense potential of blue foods to help achieve those goals.”

More than 2,500 species or species groups of fish, shellfish, aquatic plants and algae are caught or cultivated globally for food, providing livelihoods and incomes for more than 100 million and sustenance for one billion.

Because B cells are responsible for antibody production, patients’ ability to produce antibodies that prevent the virus from entering and infecting a person’s cells is significantly muted when the B cells are depleted with aCD20 treatment. But the same patients are nonetheless able to mount very good responses of the second protective arm of their immune system, which uses T cells to eliminate cells once infected (thereby preventing viral spread to other cells), according to new research from the Perelman School of Medicine at the University of Pennsylvania in a new paper published in Nature Medicine.

“The message from this study is clear — it is worthwhile for patients with MS receiving aCD20 treatment to get a COVID-19 vaccine, which will prevent severe illness,” said one of the senior authors E. John Wherry, PhD, chair of Systems Pharmacology and Translational Therapeutics and director of the Penn Institute for Immunology. “Based on this body of evidence, we urge patients with MS receiving aCD20 treatment to get a COVID-19 vaccine if they haven’t already.”

The study measured both the antibody and T cell responses in 20 patients with MS who were undergoing aCD20 treatment, compared to those in a group of healthy controls. None of the participants in the study had prior clinical signs or symptoms of COVID-19. Researchers analyzed plasma and peripheral blood mononuclear cell samples five times over the study period: prior to the first vaccine dose, 10-12 days following the first vaccine dose, prior to the second vaccine dose, 10-12 days following the second vaccine dose, and 25-30 days following the second vaccine dose.

All healthy control subjects generated both anti-spike and anti-receptor-binding domain (RBD) antibodies following the first dose of mRNA vaccine, and the level of antibody increased further after the second dose. However, in patients with MS, the antibody response was far more varied. By 30 days after the second vaccine dose, 85% of participants developed anti-spike antibodies, and 50% mounted anti-RBD responses. For those subjects who did have detectable antibodies, the magnitude of response was generally lower, and the response was delayed compared to the control group.

The timing of a patient’s last aCD20 infusion — typically administered every six months — played a significant role in the immune response mounted. Patients with MS with higher percentages of circulating B cells prior to the vaccine had more robust antibody responses to the vaccine.

“This data not only reveal that patients undergoing anti-CD20 infusions are still able to mount important COVID-19 vaccine responses which are likely to protect from severe illness, but also informs our clinical practices in how we advise patients with MS and other autoimmune disorders on such therapies,” said another of the paper’s senior authors Amit Bar-Or, MD, FRCPC director of the Center for Neuroinflammation and Experimental Therapeutics and chief of the Division of MS and Related Disorders. “For example, knowing that responses are weakest immediately following an anti-CD20 infusion, we can now advise patients to wait a number of months after their therapy to get a COVID-19 vaccine.”

Researchers found that patients who had undergone aCD20 treatments had subpopulations of T cells that responded similarly to vaccination as healthy control subjects. Patients who underwent aCD20 therapy generated robust CD4 and CD8 T cell responses to the COVID-19 vaccination. Further, the CD8 T cell response was especially robust among the subgroup of patients with MS who didn’t generate RBD antibodies. This observation reveals that even without circulating B cells, the COVID-19 vaccine effectively primed patients’ immune response to the virus.

“Often when determining if a patient mounted a proper response to an mRNA vaccine, we test for the presence of antibodies, but this method neglects an entire arm of a person’s immune response,” said one of the lead authors Sokratis A. Apostolidis, MD, a fellow in the Department of Rheumatology. “Measuring both antibodies and T-cell response gives us a more complete picture of a patient’s immune response, and reveals that patients who can’t generate antibodies as well as a healthy person are actually still protected by the COVID-19 vaccine.”

The researchers do note that due to the limited antibody responses mounted by patients receiving aCD20 treatments, they might not be able to neutralize the virus as quickly before it infects other cells, which could result in them being contagious carriers of the virus for a longer period of time.

This work was supported by grants from the NIH (AI105343, AI082630, AI108545, AI155577, AI149680, AI152236, P30-AI0450080, R01 AI118694, UC4 DK112217, T32 AR076951-01, T32 CA009140, U19AI082630, UM1 AI144288, NMSS SI-2011-37160). This work was also supported by NIH contract (Nr. 75N9301900065).

Funding was also provided by the Allen Institute for Immunology, Chen Family Research Fund, the National Multiple Sclerosis Society-American Brain Foundation Clinician Scientist Award, the Parker Institute for Cancer Immunotherapy, the Penn Center for Research on Coronavirus and Other Emerging Pathogens, the University of Pennsylvania Perelman School of Medicine COVID Fund, the University of Pennsylvania Institute for Immunology Glick COVID-19 research award, the University of Pennsylvania Perelman School of Medicine 21st Century Scholar Fund, a philanthropic gift from Jeffrey Lurie, Joel Embiid, Josh Harris, and David Blitzer, the Penn Center for Neuroinflammation and Experimental Therapeutics and the Melissa and Paul Anderson Fund.

Nations with more urban populations and strong international travel links were worst affected by the pandemic, the study shows.

Mortality rates and levels of restrictions — such as lockdowns and travel bans — were found to be lowest in countries previously thought to be at greatest risk from Covid-19.

A team of researchers from the NIHR Global Health Research Unit Tackling Infections to Benefit Africa (TIBA) from the University of Edinburgh worked with the World Health Organization (WHO) African Region to identify factors affecting mortality rates during Africa’s first two Covid-19 waves and the timing of the first reported cases.

Professor Mark Woolhouse, TIBA Director, who co-led the study, said: “Our study shows very clearly that multiple factors influence the extent to which African countries are affected by Covid-19. These findings challenge our understanding of vulnerability to pandemics.

“Our results show that we should not equate high levels of preparedness and resilience with low vulnerability.

“That seemingly well-prepared, resilient countries have fared worst during the pandemic is not only true in Africa; the result is consistent with a global trend that more developed countries have often been particularly hard hit by Covid-19.”

Among 44 countries of the WHO African Region with available data, South Africa had the highest mortality rate during the first wave between May and August 2020, at 33.3 deaths recorded per 100,000 people. Cape Verde and Eswatini had the next highest rates at 17.5 and 8.6 deaths per 100,000, respectively. At 0.26 deaths recorded per 100,000, the lowest mortality rate was in Uganda.

South Africa also recorded the highest mortality rate during the second wave between December 2020 and February 2021, at 55.4 deaths per 100,000. Eswatini and Botswana recorded rates of 39.8 and 17.7 deaths per 100,000, respectively. The lowest rate was in Mauritius, which recorded no deaths during the second wave.

“The early models which predicted how Covid-19 would lead to a massive number of cases in Africa were largely the work of institutions not from our continent. This collaboration between researchers in Africa and Europe underlines the importance of anchoring analysis on Africa’s epidemics firmly here,” said Dr. Matshidiso Moeti, WHO Regional Director for Africa and co-author. We can no longer focus our understanding of disease transmission purely on the characteristics of a virus — Covid-19 operates within a social context which has a major impact on its spread.”

As well as those with large urban populations and strong international travel links, countries with high rates of HIV were also more likely to have higher mortality rates. This may be because people with HIV often have other health conditions that put them at greater risk from Covid-19, the team suggests.

The weak link between mortality rate and the timing or severity of government-imposed restrictions on day-to-day activities is shows the impact of the wide range of application and enforcement of these restrictions across the region, making a consistent impact pattern difficult to discern. Restrictions during peaks of infection are well documented to have interrupted transmission in the region.

The findings show that the earliest recorded cases of Covid-19 were in counties where most people live in urban areas, with strong international travel links and greater testing capacity. Algeria was the first of 47 African countries to report a case, on 25 February 2020. Most countries had recorded cases by late March 2020, with Lesotho the last to report one, on 14 May 2020.

Researchers document higher deaths during the second wave, as compared to the first. The peak of infections during the second wave was also higher, with 675 deaths across the continent on 18 January 2021 compared with 323 during the first wave peak on 5 August 2020. Potential under-reporting was accounted for in the analysis.

Dr Sarah Puddicombe, NIHR’s Assistant Director for Global Health Research, said: “This study offers compelling results which challenge accepted views of epidemic preparedness and resilience in Africa. It is one of a series of important contributions that the TIBA partnership, working with governments and the WHO Regional Office has made to inform local, national and pan-African responses to the Covid-19 pandemic.”

The study, published in the journal Nature Medicine, was supported by the UK National Institute for Health Research and the Darwin Trust of Edinburgh. It also involved researchers from the Universities of Nairobi, Ghana and Hong Kong.

While risk factors for hospitalization and poor outcomes are well documented in adults, less is known about the clinical factors associated with COVID disease severity in children.

In an effort to aid mitigation strategies for children who are at high risk of developing severe COVID disease, a group of physicians at Monroe Carell Jr. Children’s Hospital at Vanderbilt studied data from 45 children’s hospitals around the country — 20,000 patients were included.

“This is one of the largest multicenter studies of children with COVID-19 in the United States,” said James Antoon, MD, PhD, FAAP, assistant professor of Pediatrics at Children’s Hospital and lead author of the study.

“And given the recent, concerning increases in COVID cases nationwide and the fact that the vast majority of children remain unvaccinated and susceptible, these findings should be taken into account when considering preventive strategies in schools and planning vaccinations when available for children less than 12 years of age,” he said.

The study, “Factors Associated with COVID-19 Disease Severity in U.S. Children,” published in the Journal of Hospital Medicine, determined the factors associated with severe disease and poor health outcomes among children presenting to the hospital with COVID. These included older age and chronic co-morbidities such as obesity, diabetes and neurologic conditions, among others.

“These factors help identify vulnerable children who are most likely to require hospitalization or develop severe COVID-19 disease,” said Antoon. “Our findings also highlight children who should be prioritized for COVID-19 vaccines when approved by the FDA.”

The retrospective cohort study noted that approximately 1 out of every 4 children admitted to the hospital with COVID developed severe disease and required ICU care during April and September, 2020.

“Across the country there is a raging debate on how best to protect children and schools from COVID-19,” said Antoon. “Some children are at increased risk for more severe disease and many of them are not yet eligible for vaccination against COVID.

“With schools opening and some already in session, these children need to be protected by vaccinating as many people as possible while also using practical strategies to limit spread, such as masking, distancing and ventilation.”

Study investigators hope that the findings will buoy mitigation efforts that proved most beneficial for children and adolescents during the pandemic, including remote learning, social distancing, hand-washing and mask-wearing both for students and teachers.

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Materials provided by Vanderbilt University Medical Center. Original written by Jessica Pasley. Note: Content may be edited for style and length.