Monday, September 09, 2024

Guardians of the reef: How parrotfish promote coral health

University of Colorado at Boulder

Neighbors can be annoying. They may be loud or intrude on your space. But is it worth fighting with them? Parrotfish choose not to.

In a new study published August 28 in the journal Ecology, a CU Boulder researcher and his collaborator revealed that the spotlight parrotfish, a brightly colored species found in the shallow waters off Florida and in the Caribbean Sea, behave more tolerantly toward neighboring parrotfish but aggressively toward strangers.

The researchers spent days underwater observing the colorful fish, providing key insight into a species that plays a critical role in both maintaining healthy coral reefs and contributing to the white sand beaches of the Caribbean.

“Parrotfish are an important part of the coral reef ecosystem and the ecological functions it provides,” said Joshua Manning, the paper’s first author and a post-doctoral researcher in the Department of Ecology and Evolutionary Biology. “Understanding their behavior will help us evaluate whether and how they can buffer the effects of climate change on coral reefs.”

The spotlight parrotfish is one of the largest parrotfish species in the Caribbean reefs, measuring about 1.5 feet long. They have strong, beak-like teeth that allow them to spend up to 90% of the day munching on microscopic organisms that grow on and within the calcium carbonate structures created by corals. As the fish remove coral skeletons, they create space for new corals to grow and produce white sand as their digestive waste.

As highly territorial animals, male spotlight parrotfish defend territories as big as two tennis courts, where they forage and mate with a small group of female followers. But not every parrotfish has a territory. Some “floaters,” as Manning calls them, constantly scout the reefs, ready to claim space that becomes available.

As a seasoned diver, Manning spent more than 400 hours underwater during his Ph.D. studies trying to understand how the spotlight parrotfish behave and interact with each other. He noticed the fish might be smarter than what many people thought.

He followed 10 spotlight parrotfish off the coast of Bonaire, a Caribbean island. He noticed that every time a floater swam by an occupied territory, the territory holders would puff up, display their fins and aggressively chase the floater away.

But when parrotfish from neighboring territories swam close to the boundary lines, territory holders were much less aggressive. When parrotfish did behave aggressively toward their neighbors, it was most often because they had strayed too far into another parrotfish’s territory while chasing another parrotfish, resulting in retaliation.

Scientists have observed this “dear enemy” effect—when territory holders exhibit less aggression toward neighbors than strangers—in squirrels, sparrows, frogs and other animals. Manning and his collaborator, Sophie McCoy, a marine biologist at the University of North Carolina, Chapel Hill, described the phenomenon for the first time in parrotfish.

Manning said that parrotfish might be more aggressive toward floaters because they are more likely to try to oust territory holders and take over their territories. While territory-holding males have better mating opportunities, their constant patrolling and defense efforts take a toll on their body condition. As a result, they must focus their energy on fighting off the most significant threats.

To the team’s surprise, floaters seemed to recognize territorial boundaries. Manning noticed that floaters often swam across the reefs using the buffer zones between established territories to avoid aggression.

“These fish may be smarter than what we give them credit for. They seem to recognize neighbors, find the boundaries of territories, and have the capacity to learn and use information,” Manning said.

Due to climate change, coral reefs are declining rapidly. Between 2023 and mid-May 2024, scientists have confirmed mass coral bleaching in at least 62 countries and territories worldwide. Coral bleaching happens when corals expel the algae living in their tissues under stressful conditions, such as high ocean temperatures, causing them to turn completely white.

Parrotfish depend on coral reefs for food and shelter. Losses in corals—due to ocean acidification and warming—can have significant impacts on their habitat and populations. At the same time, parrotfish can accelerate reef recovery from bleaching events by creating bare space for new coral larvae to settle and grow.

“Reefs are a vital source of food for us and support immense biodiversity, including species with significant medical potential. By studying how parrotfishes use space and how their grazing influences coral recruitment patterns, we can better understand how reefs can recover from disturbances and adapt to climate change," Manning said.

Journal

Ecology

DOI

10.1002/ecy.4407

For many animals sleep is a social activity, but it’s usually studied as an individual process

Cell Press

Group sleeping can impact when animals sleep, how long they sleep for, and how deeply they sleep. For example, groups of meerkats time their sleep according to “sleep traditions”; olive baboons sleep less when their group size increases; bumblebees suppress sleep in the presence of offspring; and co-sleeping mice can experience synchronized REM sleep. To fully understand both sleep and animal social structures, we need to pay more attention to the “social side” of sleep, animal behaviorists argue in an opinion paper publishing September 5 in the Cell Press journal Trends in Ecology & Evolution.

Although many animals sleep in groups, most sleep studies are conducted under laboratory conditions that only consider one animal at a time. These laboratory sleep studies provide high-resolution information on sleep depth and phase, but they are unable to capture the environmental or social contexts in which sleep usually occurs. To understand the interconnections between sleeping and sociality, the researchers say that we need to study groups of sleeping animals in the wild.

“Social sleep is a research frontier that we believe holds exciting potential for new insights into both sleep science and wild animals’ lives,” write the researchers, who include behavioral ecologists Pritish Chakravarty (@prit_chak) and Margaret Crofoot (@MegCrofoot) of the Max Planck Institute of Animal Behavior and the University of Konstanz Germany. “We propose a new framework that leverages simultaneous monitoring of the sleep of members of social groups, combined with time-series and social network analyses, to investigate how the social environment shapes (and is shaped by) sleep.”

To study sleep in the wild, the researchers recommend leveraging technologies such as wearable or implantable accelerometers, which provide information on animal movements with video or direct observations of the animals’ behavior. Pairing this sleep data with measurements of the group’s social networks like dominance hierarchies and kinship relationships, for example, could provide important ecological and evolutionary insights into the impact of sleep on the fitness and survival of both individual and groups of animals, the researchers say.

“It is likely that key aspects of group behavior, including coordination, decision-making, and cooperative potential, will be influenced by the sleep of its members,” they write. “By collecting data on sleep and sociality and applying our proposed tools to analyze social sleep, we can begin unraveling the adaptive functions and evolutionary trade-offs of sleep that may not be revealed by studying individual animals alone.”

###

This research was supported by the Max Planck Society, the Packard Foundation, the Alexander von Humboldt Foundation, the European Union, the Deutsche Forschungsgemeinschaft (German Research Foundation), the Agence Nationale de la Recherche, and a Marie Skłodowska-Curie Fellowship.

Trends in Ecology & Evolution, Chakravarty et al., “The sociality of sleep in animal groups” https://cell.com/trends/ecology-evolution/fulltext/S0169-5347(24)00176-9

Trends in Ecology & Evolution (@Trends_Ecol_Evo), published by Cell Press, is a monthly review journal that contains polished, concise, and readable reviews and opinion pieces in all areas of ecology and evolutionary science. It aims to keep scientists informed of new developments and ideas across the full range of ecology and evolutionary biology—from the pure to the applied, and from molecular to global. Visit http://www.cell.com/trends/ecology-evolution. To receive Cell Press media alerts, please contact press@cell.com.

Journal

Trends in Ecology & Evolution

DOI

10.1016/j.tree.2024.07.011

Method of Research

Commentary/editorial

Subject of Research

Not applicable

Article Title

The sociality of sleep in animal groups

Article Publication Date

5-Sep-2024

Study shows fentanyl’s role in Oregon overdose spike after policy decriminalizing drug possession

A study by public health researchers at Brown University found that decriminalization of drug possession was not associated with an increase in fatal drug overdose rates in Oregon.

Brown University

PROVIDENCE, R.I. [Brown University] — When overdose rates spiked in Oregon in 2021 after the state decriminalized low-level drug possession, blame quickly turned to the new state law. But a new study by researchers at the Brown University School of Public Health implicates another factor: the introduction of fentanyl into Oregon’s unregulated drug market.

“What's compelling about this analysis is that it follows the path of fentanyl across the country and offers testament to the destruction wreaked by this highly potent drug,” said study author Brandon del Pozo, an assistant professor of medicine (research) and health services, policy and practice (research) at Brown. “When fentanyl arrives in Oregon in early 2021, we can see from the data that it wreaks destruction there, too. That was also when decriminalization was taking effect in Oregon.”

With the implementation of Measure 110 in 2021, Oregon became the first U.S. state to decriminalize small amounts of any drug for personal use. In April 2024, in reaction to the state’s skyrocketing overdose rate and other concerns, Oregon’s governor signed into law a bill that rolled back Measure 110 by making “personal use possession” a misdemeanor punishable by up to six months in jail.

Del Pozo said that there hasn’t been an analysis of the association of Measure 110 with overdose mortality that has fully accounted for the introduction of fentanyl to Oregon’s unregulated drug market, despite the fact that fentanyl is known to be the prime driver of fatal overdose in the U.S.

In the paper, published in JAMA Network Open, del Pozo and his team evaluated the association between changes in state fatal drug overdose rates and the escalation of fentanyl availability across the country from 2008 to 2022.

Comparing Oregon to 48 U.S. states as well as Washington, D.C., that did not decriminalize drug use, they analyzed national data from state drug laboratories showing what kinds of illicit drugs were being recovered and tested. They focused on the percentage of the drug supply accounted for by fentanyl and its analogs, which increased state by state over time. The researchers then plotted this data against publicly available information from the U.S. Centers for Disease Control of each state’s fatal drug overdoses.

They found that across all states, an increase of fentanyl in the illicit drug supply was strongly correlated with an increase in drug overdose fatalities.

“It was a very tight relationship: the more fentanyl that was recovered and tested by the state, the higher the fatal overdose rate in that state,” del Pozo said.

The researchers determined the inflection point when each state experienced a rapid escalation of fentanyl in its unregulated drug market, making it the dominant illicit opioid in that state. For Oregon, that change took place in the first half of 2021. M110 took effect in February 2021.

“It was very unfortunate timing, because it means the effects of decriminalization were confounded by an event — fentanyl supply shock — that dramatically drives up fatal overdose, state by state, as it occurs,” del Pozo said.

The researchers used the data to construct a model that determined the decriminalization of drug possession in Oregon was not associated with an increase in fatal drug overdose rates in the two years after its enactment. They concluded that when evaluating the effect of public policies on overdose mortality, it is critical to account for the role of fentanyl as the principal driver of the nation’s overdose mortality epidemic.

“If we’re not modeling fentanyl’s effects on a community when we’re talking about strategies to address the overdose crisis, then we’re not following the evidence,” del Pozo said.

The change in Oregon’s drug policies that reversed Measure 110 and recriminalized drug possession took place on Sept. 1, 2024.

The study reported in this press release was funded by the National Institute on Drug Abuse, part of the National Institutes of Health, with additional support from NIH’s National Institute of General Medical Sciences, under award numbers K01DA056654 and P20GM125507. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Journal

JAMA Network Open

DOI

10.1001/jamanetworkopen.2024.31612

Method of Research

Data/statistical analysis

Subject of Research

Not applicable

Article Title

Drug decriminalization, fentanyl, and fatal overdoses in Oregon

Article Publication Date

5-Sep-2024

COI Statement

Role of the Funder/Sponsor: The funders had no role in the design and conduct of the study; 371 collection, management, analysis, and interpretation of the data; preparation, review, or 372 approval of the manuscript; and decision to submit the manuscript for publication.

State-by-state data boosts bird conservation planning

Cornell University

ITHACA, N.Y. – New data summaries from the Cornell Lab of Ornithology’s eBird platform will help state wildlife planners assess the status of bird populations that live in or pass through their state – a crucial tool in protecting species.

A team of data scientists at eBird, the participatory science platform, has packaged summaries covering every bird species, in every state, and made them available online for free. These data summaries will help states prepare their federally required 2025 updates to State Wildlife Action Plans.

“As we began to work more closely with state agencies and regional conservation partnerships, we realized that we needed to significantly increase the accessibility of eBird information for these partners,” said Viviana Ruiz-Gutierrez, assistant director of the Cornell Lab’s Center for Avian Population Studies and the driving force behind development of the state summaries.

“By providing these customized summaries, state agencies don’t have to wrangle with big data and spatial tools. They get data targeted to the area they are responsible for,” said Andrew Stillman, a postdoctoral fellow at the Cornell Lab. “It’s much more efficient, saving them time and money.”

State Wildlife Action Plans are critical to conservation in the United States, Stillman said. The plans must be updated every 10 years and submitted to the U.S. Fish and Wildlife Service for approval. Approval releases funding from the State and Tribal Wildlife Grants program, which is used to proactively conserve birds and other species that make up the biodiversity of each state.

The 2025 updates will mark the second major revision to state wildlife plans since the first plans were completed in 2005. But this is the first time eBird state data summaries will be available to inform the revisions, helping planners easily identify which species are in greatest need of conservation and to set priorities for where and when to take conservation action.

Without year-round weekly bird abundance data from eBird, an important part of the big picture is missing. For example, tundra swans don’t breed in Michigan and are not found there for most of the year. But during two weeks in March, 13% of the global population is migrating through Michigan, making marsh and wetland habitat vital for stopovers during their long journey back to their Arctic breeding grounds.

The state summaries are updated each year with new population numbers from eBird. With the latest August 2024 update, planners can now also see which way bird populations are trending for the entire state: increasing, decreasing or stable; and by how much.

“We’ll continue to refine and update the summaries so states have what they need,” Stillman said. “We’re also looking into expanding this customization for the two dozen Migratory Bird Joint Ventures in the U.S. and Canada. Birds are not known for recognizing human boundaries and joint venture partnerships work across boundaries to conserve birds and the habitats they need, where they need it. The state planners tell us, ‘Keep it coming.’”

For additional information, see this Cornell Chronicle story.

-30-

Researchers find ideal place to take reptiles’ pulse rate

Cornell University

Media note: Photos and video can be viewed and downloaded here: https://cornell.box.com/v/reptilepulses

ITHACA, N.Y. – Cornell University researchers have discovered they can consistently measure reptiles’ pulse rate in an easy-to-reach spot on the back of the head, and that pulse rate corresponds to the heart rate in healthy reptiles. The technique requires an ultrasonic Doppler flow detector, a common instrument found in most veterinary clinics.

While the location to obtain a python’s heart rate is well known, a location to obtain a pulse rate had not yet been accurately described, said Nicola Di Girolamo, associate professor of exotic animal medicine. The ability to measure pulse rate allows for a more complete cardiovascular examination.

It started with a sick bearded dragon. The lizard had an aneurysm, which caused the temporoorbital artery at the back of its head to become enlarged.

“You could put the Doppler there, and you would hear the pulse rate very well,” said Di Girolamo, corresponding author of the study. “We thought it was only happening because the vessel was so distended, but then we checked another bearded dragon kind of randomly in the same area, and we realized that it had the pulse there.”

The researchers found the pulse in the same location in other species: leopard geckos, turtles, tortoises and snakes.

Di Girolamo said he is seeing more reptile owners who are willing to seek advanced care for their pets, including surgery. This method provides another way to listen to a reptile’s heartbeat while it’s under anesthesia or to treat an animal that’s feeling defensive. “It can be easier and less stressful to do it this way,” he said.

The findings published in the journal Veterinary Record of the British Veterinary Association.

For additional information, read this Cornell Chronicle story.

Cornell University has dedicated television and audio studios available for media interviews.

-30-

Journal

Veterinary Record

DOI

10.1002/vetr.4596

Aquatic invasive species are more widespread in Wisconsin than previously thought

University of Wisconsin-Madison

MADISON — A report on more than 40 years of research on Wisconsin lakes is highlighting some of the lessons scientists have learned about aquatic invasive species, including that far more ecosystems are playing host to non-native species than previously thought.

However, the researchers note, those species aren’t necessarily detrimental to their new habitat and, in some cases, the negative “impacts of invasive species control may be greater than the impacts of the invasive species” themselves.

That doesn’t mean scientists aren’t concerned about different species moving into new ecosystems, says Jake Vander Zanden, director of the University of Wisconsin–Madison’s Center for Limnology and lead author on the report.

“There are many examples where an invasive species has remarkable ecosystem impacts. They can result in fisheries decline, water quality decrease and more, which negatively impacts humans and the environment,” Vander Zanden says.

But ecological destruction is far from a foregone conclusion in invasive species stories.

The researchers, who recently published their analysis in the journal BioScience, highlight several lessons learned through four decades of data collection, research and experiments conducted by the North Temperate Lakes Long-Term Ecological Research program. Housed at the Center for Limnology, the program is one of 27 such sites funded by the National Science Foundation.

Research grants typically fund a few years of work, Vander Zanden explains, “But that would never allow you to detect these types of changes. It’s only through long-term research that we can get insights into these big questions like where invasive species are, how they are changing our ecosystems and how it all connects to things like climate change.”

One such insight is that the presence of non-native aquatic species in Wisconsin lakes is more widespread than scientists and resource managers initially thought.

The long-term research program has helped inform Wisconsin Department of Natural Resources maps and datasets on six target species since the 1990s: Eurasian watermilfoil, zebra mussels, spiny water fleas, rusty crayfish, Chinese mystery snail and the banded mystery snail.

Combining long-term monitoring records on its 11 core study lakes with field-based research and community-based science on dozens of other water bodies, researchers revealed that existing estimates of about 8% of Wisconsin lakes containing one or more of the six species was way off. In fact, the number is closer to 39%.

Additionally, certain invasive populations have been in waters much longer than initially thought. For example, researchers detected spiny water fleas in Lake Mendota in 2009, but scientists combing through sediment cores and old samples discovered that the disruptive invasive species had been present in the lake at least a decade sooner, with populations only erupting due to favorable changes in climate that summer. These findings suggest that invasive species are often simply present in an ecosystem without triggering negative impacts.

What’s more, when invasive species do result in negative impacts, those impacts are often tied to existing problems, according to Jake Walsh, a co-author of the new paper and postdoctoral associate in the University of Minnesota’s Department of Fisheries, Wildlife, and Conservation Biology.

“Lake Mendota was especially primed for large, costly effects from spiny water flea,” says Walsh. “They worsened water quality problems that were already present and tied to excess nutrients in the lake.”

Seeing this fuller picture was only possible through long-term research, Walsh adds. “As long as we have this long-range program, invasions are experiments that can teach us about how ecosystems work and how we can best manage them,” he says. This has given us a deep understanding of the water quality issues facing Lake Mendota and a ‘road map’ to follow for offsetting spiny water flea’s impact.”

Long-term science doesn’t just help scientists piece together the history of environmental change, Vander Zanden adds. With it, researchers can also highlight looming questions and design studies to answer them. From using environmental DNA, to exploring long-term invasive species removal benefits, more discoveries are on the horizon.

And it’s not just the science that benefits from this long-term, interdisciplinary approach. Undergraduate field technicians who spent their summers sampling the same sites over and over have gone on to become professors overseeing their own research projects and managing their own students. Data scientists and staff dedicate huge chunks of time to making their datasets publicly available and accessible to other researchers in the freshwater sciences.

It’s a spirit of collaboration and exploration that, Vander Zanden hopes, can extend to other fields.

“I wonder if some of these patterns that we see from long-term data could be relevant to somebody who studies soil, or grassland flowers, or marine biology,” he says. “If invasive species are already there and more widespread than we think they are, things like human activity and climate change could soon be triggering more population shifts.”

# # #

-- Adam Hinterthuer, hinterthuer@wisc.edu; Madelyn Anderson

Journal

BioScience

Method of Research

Meta-analysis

Lack of workplace support after medication errors can worsen outcomes among healthcare professionals

University of Eastern Finland

Psychological distress is the most common negative outcome experienced by healthcare professionals after making medication errors, according to a new study from the University of Eastern Finland. After such events, turnover intentions and absenteeism were more common among those experiencing inadequate organisational support and so called second victim distress.

During this past decade, an abundance of research has been conducted regarding the prevalence and severity of the second victim phenomenon. The term “second victim”, coined by Dr. Albert Wu from Johns Hopkins University, refers to those healthcare professionals who experience emotional distress after getting involved in or witnessing severe patient safety incidents.

In the present study, a survey was conducted among nurses and physicians working at two university hospitals in Finland between September 2022 and May 2023. The 149 respondents were mainly nurses. The findings were published in the Journal of Advanced Nursing.

The study revealed that the level of organisational support received by healthcare professionals after getting involved in a medication error affects negative work-related outcomes. An increase in turnover intentions and a tendency to take absence from work was observed when there was a perceived lack of organisational support and a higher level of second victim distress among healthcare professionals. Organisational support after medication errors was perceived as low by more than a third of the respondents, which highlights the need for cultivating a more supportive work environment for healthcare providers following medication errors.

“It is time for healthcare organisations to recognise the significance of the second victim phenomenon and act towards establishing structured support systems for second victims,” says the first author of the study, Doctoral Researcher Sanu Mahat.

The study provides valuable insight into how organisational support mediates the link between the distress experienced by healthcare providers and their intention to leave their jobs and absenteeism. However, further research is needed among different healthcare professionals in Finland.

The authors point out that understanding the impact of the second victim phenomenon can help create a blame-free and just culture that prioritises learning from errors rather than blaming those who make mistakes. This enables healthcare systems to focus not only on patient safety but also on the well-being of those who provide care.

“In an organisation where just culture prevails and a constructive response to errors is encouraged, healthcare providers become more resilient, develop positive coping abilities, and can enhance their professional competencies”, the authors conclude.

Research article:

Mahat, S., Lehmusto, H., Rafferty, A. M., Vehviläinen‐Julkunen, K., Mikkonen, S., & Härkänen, M. (2024). Impact of second victim distress on healthcare professionals' intent to leave, absenteeism and resilience: A mediation model of organizational support. Journal of Advanced Nursing. https://doi.org/10.1111/jan.16291

Journal

Journal of Advanced Nursing

DOI

10.1111/jan.16291

Method of Research

Survey

Subject of Research

People

Article Title

Impact of second victim distress on healthcare professionals' intent to leave, absenteeism and resilience: A mediation model of organizational support.

Unlocking the secrets of diamond: new insights into nitrogen-vacancy center formation

Songshan Lake Materials Laboratory

image:
NV center Formation by lrradiation and Annealing Approach
view more
Credit: Taiqiao Liu, Wei Shen, and Zhaofu Zhang from Wuhan University. Fanglin Lyu and Andy Hsitien Shen from China University of Geosciences (Wuhan).

Research teams from Wuhan University and the China University of Geosciences (Wuhan) have revealed new insights into the formation mechanism of nitrogen-vacancies (NV) centers in type-Ib diamonds, a phenomenon critical to quantum sensing and computing advancements. Using a novel irradiation and annealing method, the teams demonstrated how controlled temperature and orientation can significantly increase the density and depth of NV centres, paving the way for new applications in biological imaging and quantum technologies. This study not only advances our understanding of diamond materials, but it also opens up new possibilities for using their unique properties in cutting-edge scientific and technological applications. As diamonds continue to shine in the field of materials science, this study represents a significant step toward realizing their full potential.

The nitrogen-vacancy (NV) centers in diamonds, known for their exceptional sensitivity and spatial resolution, hold a crucial position in the fields of quantum sensing, quantum computing, biofluorescent labeling, temperature sensing, and magnetic field measurements. Over recent years, researchers have explored a variety of techniques for the preparation of NV centers, including chemical vapor deposition (CVD), high-energy particle irradiation, ion implantation, and femtosecond laser irradiation followed by annealing. Among these methods, post-irradiation annealing has emerged as particularly promising, owing to its capacity to produce NV centers in high concentrations and at significant depths in diamond. However, the formation of NV centers is influenced by numerous factors, including the energy of the incident particles, annealing temperature, nitrogen concentration, and the concentration of vacancies created during irradiation. Existing studies have demonstrated that high-energy particle irradiation followed by annealing can substantially increase the concentration of NV centers. Nonetheless, optimizing the process parameters for NV center formation remains challenging due to the complexity and high cost of the experiments, coupled with the lack of comprehensive theoretical support. As a result, the atomic-scale processes governing NV center formation remain insufficiently understood.

The Solution: The researchers employ MD simulations, first-principles calculations, and experimental verifications to reveal the microscopic mechanisms and defect evolution process of NV centers prepared by irradiation-annealing of type-Ib diamond. Different incident directions ([111], [110] and [100]) and annealing temperatures (973 K, 1073 K and 1173 K) are considered. The results indicate that NV centers can be formed by three microscopic mechanisms, namely irradiation-induced NV formation (INF), irradiation with further annealing (IFA) and vacancy migration (VM) toward nitrogen to form NV centers. The threshold annealing temperature for vacancy migration depends on the orientation, with average values of 613.6 K, 700.5 K, and 531.8 K along the [111], [110], and [100] directions, respectively. It is important to note that a higher annealing temperature does not guarantee a higher yield of NV center formation, as it also depends on the crystallographic orientation. This work provides valuable insights into the formation mechanism and further controlled preparation of NV centers.

The Future: Future research will aim to enhance the controllable preparation of NV centers, with an emphasis on minimizing experimental costs.

These three formation mechanisms featured by MD simulations, first principles calculation and experiments of irradiation and annealing, enhancing the comprehension of the formation mechanism of NV centers. Three formation strategies of NV centers are as follows: irradiation-induced NV formation, irradiation with further annealing to form NV, and vacancy migration to form NV. The vacancy interchanges with nearby carbon atom by stepwise, rather than by hopping. Additionally, the annealing temperature exhibits orientation-dependent effects on vacancy migration and NV center formation, indicating that higher annealing temperatures do not necessarily result in a higher yield of NV centers.

The Impact: This work provides a comprehensive atomic-level understanding of NV center formation in diamonds, presenting a promising approach for the controllable preparation of NV centers.

The research has been recently published in the online edition of Materials Futures, a prominent international journal in the field of interdisciplinary materials science research.

Reference:
Taiqiao Liu, Fanglin Lyu, Tian Shao, Diwei Zou, Wei Shen*, Yuzheng Guo, Yuan Zhong, Chaoyang Chen, Liangchen Yi, Zhaofu Zhang* and Andy Hsitien Shen*, “Insights into the Nitrogen-vacancy Center Formation in Type-Ib Diamond by Irradiation and Annealing Approach”
DOI: 10.1088/2752-5724/ad727a

Journal

Materials Futures

DOI

10.1088/2752-5724/ad727a

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Insights into the Nitrogen-vacancy Center Formation in Type-Ib Diamond by Irradiation and Annealing Approach

HKUST engineering researchers discover an effective and environment-friendly disinfectan

Hong Kong University of Science and Technology

image:
Schematic illustration of screening halogenated phenolic DBPs for potential disinfectants based on their structural properties and photodegradation kinetics.
view more
Credit: HKUST

A widely used disinfectant worldwide, chloroxylenol, has been associated with eco-toxicological threats in water environments due to its relatively high chemical stability and massive consumption. Researchers at the School of Engineering of the Hong Kong University of Science and Technology (HKUST) have discovered a promising alternative known as 2,6-dichlorobenzoquinone (2,6-DCQ), which works more effectively in combating certain common bacteria, fungi and viruses, and can be rapidly degraded and detoxified in receiving waters.

This groundbreaking study is led by Prof. ZHANG Xiangru from HKUST's Department of Civil and Environmental Engineering, who has been studying disinfection byproducts (DBPs) for many years. During the pandemic outbreak, Prof. Zhang noticed that chloroxylenol is structurally similar to some halo-phenolic DBPs previously discovered by his team, which have been shown to rapidly degrade by solar photolysis.

Inspired by the structural property and degradability of some halo-phenolic DBPs, the research team managed to select an effective broad-spectrum disinfectant from the DBPs that can be rapidly degraded and detoxified in receiving waters. The research team tested the efficacy of 10 different DBPs in inactivating various pathogens, including E. coli (a type of bacteria associated with colorectal cancer), Staphylococcus aureus (bacteria), Candida albicans (fungi), and bacteriophage MS2 (viruses). They found that 2,6-DCQ was 9 to 22 times more effective than chloroxylenol in inactivating these bacteria, fungi, and viruses.

Furthermore, they found that the developmental toxicity of 2,6-DCQ to marine polychaete embryos decreased quickly due to its rapid degradation via hydrolysis in receiving seawater, even in the absence of sunlight. Two days after being discharged into seawater, 2,6-DCQ exhibited 31 times lower developmental toxicity compared to chloroxylenol.

“We discovered that the selected DBP exhibited substantially stronger antimicrobial efficacy than chloroxylenol and that its concentration and associated developmental toxicity in receiving seawater decreased rapidly, even in darkness,” Prof. Zhang said.

He emphasized the pressing need for more effective and eco-friendly disinfectants, particularly in the wake of the COVID-19 pandemic. “Chloroxylenol has been frequently detected in aquatic environments; for instance, its concentration has reached up to 10.6 μg/L in river water in Hong Kong. Toxicological studies have reported adverse effects of chloroxylenol on aquatic organisms, including endocrine disruption, embryonic mortality, and malformations. Chronic exposure to chloroxylenol at environmental concentrations (~4.2 μg/L) can cause gene regulation and morphological changes in rainbow trout.”

The team's discovery of 2,6-DCQ as a promising alternative is an important step towards addressing this global need. The results suggest that 2,6-DCQ may be used as a disinfectant on a wide range of occasions, including personal care products (such as hand cleansers, detergent, and soap), paint, textiles, metal working fluids, medical scrubs, as well as sanitation for households, food processing equipment, surgical instruments, and public places.

“This innovative study not only provides a potential solution to better support human biosecurity while prioritizing environmental sustainability, but also carries significant implications for the development of green disinfectants and other green industrial products by exploiting the slightly alkaline nature of seawater. For example, scientists may design and develop other industrial products such as pesticides, pharmaceuticals, and personal care products that can be rapidly degraded by hydrolysis in receiving seawater,” Prof. Zhang elaborated.

Their findings have been published in the first-rate multidisciplinary journal Nature Communications. The research team included Dr. HAN Jiarui, currently a Research Assistant Professor at HKUST, and Dr. LI Wanxin, currently an Assistant Professor at Xi'an Jiaotong-Liverpool University. They are both PhD graduates from HKUST's Department of Civil and Environmental Engineering and were postdoctoral fellows in Prof. Zhang’s group during the study.

Looking ahead, Prof. Zhang plans to explore the relationships between disinfection efficiency and degradability of halophenols with their molecular fingerprints through machine learning. He hopes future investigations will shed light on the further development of optimal disinfectants.

Journal

Nature Communications

DOI

10.1038/s41467-024-48752-w

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

An effective and rapidly degradable disinfectant from disinfection byproducts