. Scientific Frontline

Tuesday, October 24, 2023

Killer whales’ diet more important than location for pollutant exposure

Photo Credit: Thomas Lipke

Both elegant and fierce, killer whales are some of the oceans’ top predators, but even they can be exposed to environmental pollution. Now, in the largest study to date on North Atlantic killer whales, researchers in the American Chemical Society’ Environmental Science & Technology report the levels of legacy and emerging pollutants in 162 individuals’ blubber. The animals’ diet, rather than location, greatly impacted contaminant levels and potential health risks — information that’s helpful to conservation efforts.

As the largest member of the dolphin family, killer whales, also known as orcas, are found worldwide. Marine vessel traffic can disturb the hunting and communication of these black-and-white marine mammals. But they face another type of human threat — legacy and emerging persistent organic pollutants (POPs) in their environments. POPs include chlorinated hydrocarbons and flame retardants, and can accumulate in animals’ fat stores as the contaminants move up the food chain though a process called biomagnification.

Getting maximum calories in shortest time is the priority for bumblebees

Photo Credit: Michael Hodgins

A new study investigating nectar drinking in one of the most common bumblebees in the UK, Bombus terrestris, has found that when foraging they maximize the amount of nectar sugar, they take back to the colony each minute.

To make their choices, the bumblebees trade off the time they spend collecting nectar with the energy content of that nectar. This means they will forage to collect nectar that’s hard to access – but only if the sugar content of that nectar makes it worth doing so.

This big-and-fast approach contrasts with honeybee foraging: honeybees make their decisions by optimizing their individual energy expenditure for any nectar they collect. This more measured approach should prolong the honeybee’s working life.

“As they forage, bumblebees are making decisions about which nectar sources will give the greatest immediate energetic return, rather than optimizing the energy efficiency of their foraging,” said Dr Jonathan Pattrick, joint first author of the report, who started the research while in the University of Cambridge’s Department of Plant Sciences.

Pattrick, now based at the University of Oxford, added: “Our results allow us to make predictions about the sorts of flowers the bumblebees are likely to visit, which could inform the choice of which flowers to plant in field margins to support these important pollinators. It’s also relevant to crop breeders who want to make varieties that are ‘better’ for bumblebees.”

Unlocking the secrets of plant cell communication

Jung-Youn Lee, a University of Delaware professor of plant molecular and cellular biology and the interim director of the Delaware Biotechnology Institute, is researching cell-to-cell communication in plants. 
Photo Credit: Evan Krape | Illustration Credit: Jeffrey C. Chase

Traffic lights signal to cars and buses when to stop, slow and go. Like traffic lights, plant cells send signals to each other to perform photosynthesis to grow or fight off destructive viruses and pathogens. 

Plant cells produce plasmodesmata, tiny tubes that act as communication channels, allowing those signals to move from cell to cell. The plasmodesmata will open and close in response to various signals that activate protein regulators such as PDLP5.  

“We knew that this protein is critical for plant defense,” said Jung-Youn Lee, a University of Delaware professor of plant molecular and cellular biology and the interim director of the Delaware Biotechnology Institute. “But how does this protein get to the plasmodesmata?”

The question — how these protein regulators find their destination to fulfill their purpose and help a cell function — had been plaguing scientists. Until the University of Delaware got involved.

In new research that made the cover of the journal The Plant Cell, UD researchers found that the protein — PDLP5 — that helps guard plants from the invasion of viruses and bacteria has not one, but two special targeting signals, or “zip codes'' as Lee calls them, unexpectedly stationed outside of cells. 

U of M study suggests even more reasons to eat your fiber

Photo Credit: Melissa Belanger

Health professionals have long praised the benefits of insoluble fiber for bowel regularity and overall health. New research from the University of Minnesota suggests even more reasons we should be prioritizing fiber in our regular diets. In a new study published in Nutrients, researchers found that each plant source of insoluble fiber contains unique bioactives — compounds that have been linked to lower incidence of cardiovascular disease, cancer and Type 2 diabetes — offering potential health benefits beyond those of the fiber itself. 

“People understand the need for fiber and how it relates to gut health — an area of wellness that is becoming increasingly important as scientific research continues to reveal its impact on overall health and wellbeing,” said Joanne Slavin, co-author of the paper and a professor in the College of Food, Agricultural and Natural Resource Sciences at the University of Minnesota. “Fiber is the marker of health that is included in our dietary guidelines and found on product labels, but our research indicates that we need to ensure the other valuable components of fiber-containing plant sources — the bioactives — are also recognized as providing valuable benefits for human health.” 

The study aggregated the available literature on the health benefits of bioactives in plant sources of insoluble dietary fiber.

Case report shows promising results using transcranial magnetic stimulation for post-stroke ataxia

Image Credit: UCLA| Health et al. Cerebellum. October 21, 2023

In a new case report, researchers at UCLA Health describe promising results using repetitive transcranial magnetic stimulation (rTMS) in the management of post-stroke cerebellar ataxia, a debilitating condition marked by impaired coordination and balance.

Cerebellar ataxia describes a group of neurological disorders that affect coordination, balance, and control of muscle movements. It results from damage or dysfunction of the cerebellum, a part of the brain responsible for coordinating voluntary movements. Ataxia can manifest as unsteady walking, difficulties with fine motor skills, and problems with speech, among other symptoms. The severity of ataxia can vary from mild to severe, and treatments often aim to manage symptoms and improve a person's quality of life as treatment options are limited.

Writing in The Cerebellum, researchers led by Evan Hy Einstein, Department of Psychiatry & Biobehavioral Sciences at the UCLA David Geffen School of Medicine, report on the case of a 58-year-old male who had experienced a cerebellar hemorrhage approximately 12 years previously. Despite intensive rehabilitation, symptoms such as slow and unsteady gait, balance issues, and urinary incontinence persisted over the years. The patient sought consultation for potential rTMS treatment. His primary complaints focused on his slow and unsteady gait, along with challenges related to balance and stability. The decision was made to employ bilateral cerebellar rTMS, representing an innovative approach to address the condition.

How Huntington’s Disease Begins Before Symptoms Appear

A microglia cell (shown in green) and corticostriatal synapses (purple) from a patient with Huntington’s disease.
Image Credit: Dan Wilton

A new study led by researchers at Boston Children’s Hospital and Harvard Medical School reveals how the process of Huntington’s disease begins well before symptoms appear — and shows that in mice, the process can be blocked to prevent cognitive problems related to Huntington’s.

If the findings hold true in humans, they raise the possibility of intervening early in the disease in people who carry the Huntington’s gene mutation.

The work, published in Nature Medicine, also could shed light on other neurodegenerative disorders.

The team found in patient tissue samples and mouse models that two players in the immune system — complement proteins and microglia — are activated very early in Huntington’s, leading to loss of synapses in the brain before cognitive and motor symptoms emerge. The researchers revealed how and where the synapses are lost.

The findings corroborate a potential treatment that’s currently in clinical trials for the disease.

The study was led by senior author Beth Stevens, HMS associate professor of neurology at Boston Children’s, and first author Dan Wilton, HMS research fellow in neurology in the Stevens lab.

Cathode active materials for lithium-ion batteries could be produced at low temperatures

Reaction pathway of the hydroflux process to form layered lithium cobalt oxide (LiCoO2) at 300 °C.
Full Size Image
 Illustration Credit: Masaki Matsui

Lithium-ion batteries (LIB) are the most commonly used type of battery in consumer electronics and electric vehicles. Lithium cobalt oxide (LiCoO2) is the compound used for the cathode in LIB for handheld electronics. Traditionally, the synthesis of this compound requires temperatures over 800°C and takes 10 to 20 hours to complete.

A team of researchers at Hokkaido University and Kobe University, led by Professor Masaki Matsui at Hokkaido University’s Faculty of Science, have developed a new method to synthesize lithium cobalt oxide at temperatures as low as 300°C and durations as short as 30 minutes. Their findings were published in the journal Inorganic Chemistry.

“Lithium cobalt oxide can typically be synthesized in two forms,” Matsui explains. “One form is layered rocksalt structure, called the high-temperature phase, and the other form is spinel-framework structure, called the low-temperature phase. The layered LiCoO2 is used in Li-ion batteries.”

Scientists from UNSW Sydney reveal biases in the field of coral reef research

Photo Credit: Vincent Rivaud

Analysis of the literature revealed authors from countries with large coral reef systems, such as The Maldives, Papua New Guinea and Indonesia, are underrepresented. 

Coral reefs support approximately 25 per cent of marine species, and are essential to coastal economies, such as the fishing and tourism industries, to name a few. But coral reefs worldwide are at risk due to climate change and are on the brink of collapse. 

The global decline of coral reefs has encouraged extensive research. Now, scientists from UNSW Sydney have assessed the current landscape of coral health research to reveal biases in the field.  

The team discovered that most papers on coral reef research are published from within the US and Australia, while researchers from countries with large coral reefs, such as The Maldives and Papua New Guinea, are underrepresented. As these reefs are also on the brink of collapse, the UNSW research team emphasizes the importance of local experts to be included. 

They also identified key topic areas that are underrepresented within the existing literature, including coral bioerosion and the microbiome, both of which are important to paint a more complete picture of the state of our reefs.  

Preventing Airborne Infection without Impeding Communication with Ions and Electric Field

Figure 1.
Novel device for preventing airborne infection The design (a) and schematic (b) of the mechanism of the device for capturing infectious droplets and aerosols without hindering communication. The negatively charged ions attach to the droplets and the electric field guides them to the collecting electrode.
Illustration Credit: Courtesy of Tokyo Institute of Technology

A novel device developed by Tokyo Tech researchers in a new study utilizes ions and an electric field to effectively capture infectious droplets and aerosols, while letting light and sound pass through to allow communication. The innovation is significant in the wake of the COVID-19 pandemic, since it shows promise in preventing airborne infection while facilitating communication.

Airborne infections, such as H1N1 influenza, SARS, and COVID-19, are spread by aerosols and airborne droplets. While droplet/aerosol transmission can be prevented using acrylic partitions or, as with the COVID-19 pandemic, by imposing lockdowns in severe cases, these countermeasures can significantly impede communication. This, in turn, can lead to unintended consequences.

For instance, lockdown measures during the COVID-19 pandemic led to severe economic losses as well as a rise in cases of mental illness like depression and suicide around the world. Therefore, as we prepare for a potential future pandemic, it is necessary to develop more sustainable countermeasures that do not disrupt economic activities and daily face-to-face interactions.

To this end, a research team including Kaito Kanda, a graduate student at Tokyo Institute of Technology (Tokyo Tech) at the time of research, Assistant Professor Tetsuya Yamada, from the Institute of Innovative Research at Tokyo Tech, and Professor Takeo Fujiwara from Tokyo Medical and Dental University (TMDU) and Chiba University researchers, has now developed a device that successfully captures droplets and aerosols while allowing the transmission of light and sound for effective communication.

Small but mighty: the hidden power of broccoli sprouts

The study revealed that the total polysulfide content of broccoli sprouts was significantly higher than that of mature broccoli   
Photo Credit: Osaka Metropolitan University

Broccoli sprouts have been discovered to contain seven times more polysulfides than mature broccoli

Scientists investigated how germination impacts the polysulfide content and composition of broccoli sprouts

Remember when your parents used to say, “Eat your greens, they are good for you”? Well, they were really onto something. Several studies have shown that higher intakes of cruciferous vegetables like broccoli, one of the most widely consumed vegetables in the United States, are associated with reduced risks of diseases such as diabetes and cancer, thanks to their organosulfur compounds, such as glucosinolates and isothiocyanates that exhibit a broad spectrum of bioactivities including antioxidant activity. However, few studies have focused on the endogenous content of polysulfide in broccoli sprouts.

A research team led by Assistant Professor Shingo Kasamatsu and Professor Hideshi Ihara of the Graduate School of Science at Osaka Metropolitan University, investigated the amount of polysulfides in broccoli sprouts during the process of their germination and growth. Building upon their previous work, the research team demonstrated the abundance of polysulfide molecules in cruciferous vegetables.

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