Defined as the largest animals in the oceans, with a body mass that exceeds 45kg, examples include sharks, whales, seals and sea turtles.

These species serve key roles in ecosystems, including the consumption of large amounts of biomass, transporting nutrients across habitats, connecting ocean ecosystems, and physically modifying habitats.

Traits, such as how large they are, what they eat, and how far they move, determine species’ ecological functions. As a result, measuring the diversity of traits allows scientists to quantify the contributions of marine megafauna to ecosystems and assess the potential consequences of their extinction.

The team of researchers — led by Swansea University’s Dr Catalina Pimiento — first compiled a species-level trait dataset for all known marina megafauna to understand the extent of ecological functions they perform in marine systems.

Then, after simulating future extinction scenarios and quantifying the potential impact of species loss on functional diversity, they introduced a new index (FUSE) to inform conservation priorities.

The results showed a diverse range of functional traits held by marine megafauna, as well as how the current extinction crisis might affect their functional diversity.

If current trajectories are maintained, in the next 100 years we could lose, on average, 18% of marine megafauna species, which will translate in the loss of 11% of the extent of ecological functions. Nevertheless, if all currently threatened species were to go extinct, we could lose 40% of species and 48% of the extent of ecological functions.

Sharks are predicted to be the most affected, with losses of functional richness far beyond those expected under random extinctions.

Dr Catalina Pimiento, who led the research from Swansea University said:

“Our previous work showed that marine megafauna had suffered an unusually intense period of extinction as sea levels oscillated several million years ago. Our new work shows that, today, their unique and varied ecological roles are facing an even larger threat from human pressures.”

Given the global extinction crisis, a crucial question is to what extent nature holds a back-up system. In the event of extinction, will there be remaining species that can perform a similar ecological role?

Dr John Griffin, a co-author on the study from Swansea University adds:

“Our results show that, among the largest animals in the oceans, this so-called “redundancy” is very limited — even when you roll in groups from mammals to molluscs. If we lose species, we lose unique ecological functions. This is a warning that we need to act now to reduce growing human pressures on marine megafauna, including climate change, while nurturing population recoveries.”

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“By understanding these early stages of pancreas disease, we hope our work will lead to the development of new strategies to diagnose and treat pancreatitis and pancreatic cancer early on,” says Wahl, co-corresponding author and holder of the Daniel and Martina Lewis Chair in Salk’s Gene Expression Laboratory.

The pancreas is an abdominal organ that plays a role in digestion and blood sugar regulation. Yet, scientists know little about how the pancreas recovers from injuries, such as pancreatitis, or fights off pancreatic cancer. Most of the pancreas is composed of acinar cells, which produce and secrete digestive enzymes. Acinar cells also have the ability to transform into another type of cell called a tuft cell. Scientists do not know all of the functions of tuft cells, but previous work showed that intestinal tuft cells secrete the protein IL-25 to support the immune response during parasitic infections.

“Since cancer has been called ‘the wound that never heals,’ we wanted to investigate how the pancreas heals from pancreatitis to better understand pathways that may be co-opted by cancer,” says Razia Naeem, co-first author and laboratory technician in the Wahl lab.

The researchers used a combination of techniques including histology, imaging and molecular strategies to characterize tuft cell populations in pancreatitis mouse models. They found that, although the pancreas does not normally contain tuft cells, during pancreatitis acinar cells undergo complex changes to become tuft cells, as a normal part of pancreatic injury and recovery. This transformation is similar to a reserve soldier (acinar cell) who must then change from their civilian clothes into that of a soldier (tuft cell) to fight off the enemy of inflammation.

The researchers also observed that the pancreatitis-induced tuft cells secreted IL-25 to promote the immune response, similar to what had previously been found in the intestine. Thus, tuft cells may play a role modulating the immune system during pancreatitis.

The scientists examined tuft cell formation in seven strains of mice to see if there were any differences during the development of pancreatitis. Surprisingly, the team found that tuft cell formation did not occur in all strains of mice. The most genetically diverse animals produced the most tuft cells, suggesting that tuft cell formation is either controlled genetically or by influences on gene expression (epigenetics).

“The genetic susceptibility of tuft cell formation may represent a critical factor in pancreatitis formation, severity and progression to cancer in humans,” says Kathleen DelGiorno, first and co-corresponding author of the paper and staff scientist in the Wahl lab. “Our work demonstrates that it’s important to use the right mouse model to study pancreatitis and pancreatic cancer for there to be relevance to humans.”

The team’s work shows that using genetically diverse mice may better represent the complex human genome, allowing for more translatable modeling of disease in the lab, according to Wahl. The findings could mean that some people may be more susceptible to getting pancreatitis than others.

Next, the group plans to follow up on their gene expression analyses to pinpoint which genes control tuft cell formation in pancreatitis and whether tuft cells affect progression to pancreatic cancer. Their biggest hope is that their results will help pave the way for more targeted treatments for pancreatitis and cancer.

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Ke Du and Blanca Lapizco-Encinas, both faculty-researchers in Rochester Institute of Technology’s Kate Gleason College of Engineering, worked with an international team to collaborate on the design of the new system — a microfluidic device, essentially a lab-on-a-chip.

Drug-resistant bacterial infections are causing hundreds of thousands of deaths around the world every year, and this number is continuously increasing. Based on a report from the United Nations, the deaths caused by antibiotics resistance could reach to 10 million annually by 2050, Du explained.

“It is urgent for us to better detect, understand, and treat these diseases. To provide rapid and accurate detection, the sample purification and preparation is critical and essential, that is what we are trying to contribute. We are proposing to use this novel device for virus isolation and detection such as the coronavirus and Ebola,” said Du, an assistant professor of mechanical engineering whose background is in development of novel biosensors and gene editing technology.

The lab team is interested in the detection of bacterial infection, especially in bodily fluids. One of the major problems for detection is how to better isolate higher concentrations of pathogens.

The device is a sophisticated lab environment that can be used in field hospitals or clinics and should be much faster at collecting and analyzing specimens than the commercially available membrane filters. Its wide, shallow channels trap small bacteria molecules that are attracted to packed, magnetic microparticles.

This combination of the deeper channels on the nano-device, increased flow rate of fluids where bacteria are suspended, and the inclusion of magnetic beads along the device channels improves upon the process of capturing/isolating bacterial samples. Researchers were able to successfully isolate bacteria from various fluids with a microparticle-based matrix filter. The filter trapped particles in small voids in the device, providing a larger concentration of bacteria for analysis. An added advantage of a smaller device such as this allows for multiple samples to be tested at the same time.

“We can bring this portable device to a lake which has been contaminated by E. coli. We will be able to take a few milliliters of the water sample and run it through our device so the bacteria can be trapped and concentrated. We can either quickly detect these bacteria in the device or release them into certain chemicals to analyze them,” said Du, whose earlier work focused on devices that use the CRISPR gene-editing technology and the fundamental understanding of fluidic dynamics.

Teaming up with Lapizco-Encinas, a biomedical engineer with expertise in dielectrophoresis — a process that uses electrical current to separate biomolecules — their collaboration provided the increased capability toward better pathogen detection, specifically for bacteria and microalgae isolation and concentration.

“Our goal is not only isolating and detecting bacteria in water and human plasma, but also working with whole blood samples to understand and detect blood infection such as sepsis. We already have a concrete plan for that. The idea is to use a pair of the nano-sieve devices for sequential isolation,” said Lapizco-Encinas, an associate professor in RIT’s biomedical engineering department.

Du and Lapizco-Encinas were part of a team that consisted of mechanical and biomedical engineers from Rutgers, University of Alabama, SUNY Binghamton, and Tsinghua-Berkeley Shenzhen Institute in China to address the global challenges of disease pandemics. The new data is published in the article “Rapid Escherichia coli trapping and retrieval for bodily fluids via a three-dimensional bead-stacked nano-device,” in the journal ACS Applied Materials and Interfaces.

The research team is RIT engineering doctoral and graduate students Xinye Chen, Abbi Miller and Qian He; University of Alabama assistant professor of electrical and computer engineering Yu Gan and undergraduate student Shengting Cao; Ruo-Qian Wang, assistant professor of civil and environmental engineering from Rutgers University; Xin Yong, assistant professor of mechanical engineering from SUNY Binghamton; Peiwu Qin from the Center of Precision Medicine and Healthcare, Tsinghua-Berkeley Shenzhen Institute, China; and Jie Zhang, Carollo Engineers Inc. in Seattle.

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These questions are also crucial as part of scientific efforts to understand the role of early history of Pacific islanders on contemporary public health problems including obesity and associated non-communicable diseases such as hypertension and Type 2 diabetes.

A new study in Proceedings of the National Academy of Sciences analyzed the genomes of 1,197 individuals in Samoa and found that the effective population size of the first Samoans was small — ranging from 700 to 3,400 people during the time period from approximately 3,000 to about 1,000 years ago. Starting about 1,000 years ago, population size rapidly increase to about 10,000 individuals, coinciding with increasing agricultural and socio-political complexity, but also with previously hypothesized contacts with other Oceanic peoples.

This population history scenario for Samoa is consistent with the existing archaeological evidence of few, widely scattered and small-sized settlements in the first 2,000 years after Samoa’s initial settlement. But it contrasts with archaeological population reconstructions of much larger population sizes for adjacent Pacific peoples in Tonga and Fiji during that first 1,500 to 2,000 years after initial discoveries around 3,000 years ago.

The research team’s conclusions could help in understanding health conditions of particular importance to people in Samoa, home to some of the highest rates of obesity, heart disease and diabetes in the world.

“These findings are relevant for our ongoing public health research in Samoan populations because they highlight the importance of population history and size in influencing our ability to identify the effect of novel genetic variations, and their interactions with 21st century environments on population health,” said Stephen McGarvey, study co-author and a professor of epidemiology and of anthropology at Brown University.

McGarvey has studied extensively obesity and diseases that stem from obesity — including diabetes, cardiovascular disease, kidney disease and cancer — in Samoa, which are not only a threat to individual health, but to the nations’ economic and social development.

“Smaller populations and the evolutionary mechanisms resulting from them, including genetic drift from bottlenecks and natural selection from novel challenging environments such as experienced by the first settlers of Samoa, make it easier to detect new gene variants and different frequencies of known variants that affect cardiometabolic disease risk factors now in the 21th century,” he said.

The new study also found that modern Samoans derive largely from the Austronesian lineage, including the aboriginal peoples of Taiwan, Island Southeast Asia, coastal New Guinea and other island groups of Oceania — but share 24% of their ancestry with Papuans, the descendants of the people who settled Papua/New Guinea, an estimate markedly lower than found in neighboring Polynesian groups.

The researchers also found strong evidence of population reduction coincident with outside contact from European-derived groups, presumably from infectious diseases new to Samoan immune systems and societal shocks from such epidemics. The whole genome sequence data from participants’ DNA also enabled findings about some genetic diversification within Samoa that may be reflective of regional and local social processes. The genomic data also showed an increase in population size about 150 years ago.

“These findings indicate that the modern Samoan population is a result of these demographic dynamics from the earliest times 3,000 years ago to the very recent colonial period in the 19th century,” McGarvey said. “Any questions about putative genetic influences and their interactions with modern ways of life must be asked in the context of population history.”

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University of Otago Archaeology Programme Professor and report co-author Glenn Summerhayes says findings in Emergence of a Neolithic in highland New Guinea by 5000 to 4000 years ago, provide insights into when and how the highlands were first occupied; the role of economic plants in this process; the development of trade routes which led to the translocation of plants and technologies; and an associated record of landscape, environment and climate change through time.

The report details the earliest figurative stone carving and formally manufactured pestles in Oceania, dating to 5050 to 4200 years ago, which were found at a dig site in Waim. Also found were the earliest planilateral axe-adzes uncovered in New Guinea to date, and the first evidence for fibrecraft and interisland obsidian transfer from neighbouring islands over distances of at least 800km.

“The new evidence from Waim fills a critical gap in our understanding of the social changes and technological innovations that have contributed to the developing cultural diversity in New Guinea,” Professor Summerhayes says.

The combination of symbolic social systems, complex technologies, and highland agricultural intensification supports an independent emergence of a Neolithic around 1000 years before the arrival of Neolithic migrants, the Lapita, from Southeast Asia. When considered together with a growing corpus of studies indicating expansion and intensification of agricultural practices, these combined cultural elements represent the development of a regionally distinct Neolithic.

The research establishes dating for other finds at the site, including a fire lighting tool, postholes, and a fibrecraft tool with ochre, possibly used for colouring string fibre.

The report suggests increased population pressure on the uneven distribution of natural resources likely drove this process, which is further inferred by language and genetic divergence.

The project arose out of an Australian Research Council Grant awarded to Dr Judith Field (University of New South Wales) and Professor Summerhayes.

“Former Otago postgraduate student Dr Ben Shaw was employed as postdoctoral fellow to do the “leg work in the field” and Dr Anne Ford (Otago Archaeology Programme) contributed to understandings of the stone tool technologies. As it worked out many of these rich discoveries were made by Dr Shaw. It was one of the best appointments Dr Field and I have ever made. I am proud of our Otago graduates who are some of the best in the world.”

Professor Summerhayes and his team had previously completed a Marsden funded project in the Ivane Valley of Papua, establishing the beginning of human occupation at 50,000 years ago. The results of this work were published in Science in 2010.

“This project is a follow-on where we wanted to construct a chronology of human presence in the Simbai/Kaironk Valley of Papua New Guinea by systematic archaeological survey with subsequent excavation and analysis of a select number of sites.

“This work tracks long-term patterns of settlement history, resource use and trade, and establishes an environmental context for these developments by compiling vegetation histories, with particular attention paid to fire histories, indicators of landscape disturbance and markers of climate variability. This will add to understandings of peoples’ impact on the environment.”

Professor Summerhayes received a Marsden grant in late 2019 for his project “Crossing the divide from Asia to the Pacific: Understanding Austronesian colonisation gateways into the Pacific.” This will involve work in the Ramu Valley, which was once part of an inland sea, and will tie in the developments of Highland New Guinea, with the movements of Austronesian speakers into the Pacific.

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