It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Credit: Ascension Island Government Conservation & Fisheries Directorate
Under-sea mountains are key locations for predators – with 41 times more sharks than the open ocean, new research shows.
The study – led by the University of Exeter and the Ascension Island Government – examined three seamounts off Ascension Island in the South Atlantic Ocean.
Two were shallow seamounts, with peaks less than 100 metres below the surface – and these were teeming with vast numbers of predators, including sharks and tuna.
“Seamounts have been likened to oases of life in the comparative deserts of the open ocean,” said Dr Sam Weber, from the Centre for Ecology and Conservation on Exeter’s Penryn Campus in Cornwall.
“However, this hasn’t been studied in detail – meaning we’ve been unsure about why seamounts attract so many marine top predators.”
Some seamounts create upwellings of minerals that support bountiful phytoplankton (tiny drifting plants that are the first link in ocean food chains).
Such quantities of phytoplankton can support increased numbers of other species, from zooplankton (which eat phytoplankton) all the way to top predators like sharks.
But this study found no evidence of increased “primary productivity” of phytoplankton at the Ascension seamounts.
Instead, enrichment of marine life (measured by “biomass” – the total weight of organic material) goes up with each level of the food web.
Zooplankton were twice as common at shallow seamounts than in the open ocean, while shark biomass was 41 times higher.
“Our findings suggest that several factors combine to make seamounts so rich in sea life, especially predators,” Dr Weber said.
“While primary productivity is not higher at the seamounts we studied, filter feeders may benefit from prey being ‘blown over’ the peak, and the peak may also stop prey species from retreating into deeper water to avoid predators. This effectively concentrates food in one predictable spot in the ocean.
“Also, some predators appear to use seamounts as ‘hubs’ to gather, socialise, mate or rest, and as a base to return to after hunting in the open ocean. This may lead to more top predators on seamounts than you would expect based on the amount of food available.”
The findings suggest certain species tend to gather at seamounts – including Galapagos and silky sharks, and yellowfin and bigeye tuna.
Some individual animals were found to be “resident” – living at a particular seamount most of the time – and others visited both shallow seamounts in the study (80km apart).
The study also found a “halo” of increased marine life around seamounts, extending at least 5km into the open ocean.
The seamounts in the study are all within the Ascension Island Marine Protected Area – a 445,000 square km zone where no large-scale commercial fishing or seabed mining are allowed.
“Our results reinforce the conservation significance of shallow seamounts for many top predators,” Dr Weber said.
“This research also offers fundamental insights into seamounts’ role as activity hubs and oases for marine species and shows how these remarkable habitats influence the oceans that surround them.”
Data for the study was collected by a National Geographic Pristine Seas expedition aboard the British Antarctic Survey research vessel RRS James Clark Ross
The research was funded by a European Union BEST grant and the UK government’s Darwin Initiative.
The play-like behaviour of the flies described by the researchers, involving voluntary passive movements such as swinging, bobbing, sliding or turning, has now been demonstrated in insects for the first time. “This could help us to find out how we humans also develop efficient self-awareness of our bodies,” explains Huetteroth, whose study was funded by the German Research Foundation (DFG).
In collaboration with Northumbria University, the researchers conducted a detailed analysis of how the flies interacted with the carousel. While many flies avoided the carousel, others visited it repeatedly and for long periods. When two carousels rotated alternately, the flies even actively followed the stimulation.
The scientists placed a total of 190 individual flies in a carousel arena, a glass dome about one centimetre high, and then filmed them for 3 to 14 days. The positions of the flies in the recordings were then automatically recognised and tracked using special software. Only a fraction of the data generated was included in the study. “Using several carousels, we generated and analysed a total of around seven years of film data,” says Dr Tilman Triphan, the first author of the study. This effort was necessary because, unlike most behavioural experiments on flies, the researchers had to rely on the insects’ voluntary behaviour. There was not enough space under the glass dome for the flies to fly onto the carousel. “However, we were able to distinguish whether the flies had deliberately walked onto the carousel or jumped onto it in an uncoordinated way. This allowed us to show that unplanned visits to the carousel were rather atypical for the playing flies,” says co-author Dr Clara H. Ferreira, an assistant Professor at Northumbria University.
According to Huetteroth, the findings will now allow a detailed investigation of the underlying genetic, neuronal and biochemical factors that influence the fruit fly’s playful behaviour and the benefits this has for playful creatures in general.
This “tiny house lab,” which sits outside of Purdue University’s Delon and Elizabeth Hampton Hall of Civil Engineering, allows researchers to study indoor air quality more comprehensively than has been possible in other settings.
WEST LAFAYETTE, Ind. — When you walk through a pine forest, the crisp, fresh scent is one of the first things you notice.
But bringing that pine scent or other aromas indoors with the help of chemical products — yes, air fresheners, wax melts, floor cleaners, deodorants and others — rapidly fills the air with nanoscale particles that are small enough to get deep into your lungs, Purdue University engineers have found over a series of studies.
These nanoparticles form when fragrances interact with ozone, which enters buildings through ventilation systems, triggering chemical transformations that create new airborne pollutants.
“A forest is a pristine environment, but if you’re using cleaning and aromatherapy products full of chemically manufactured scents to recreate a forest in your home, you’re actually creating a tremendous amount of indoor air pollution that you shouldn’t be breathing in,” said Nusrat Jung, an assistant professor in Purdue’s Lyles School of Civil and Construction Engineering.
Nanoparticles just a few nanometers in size can penetrate deep into the respiratory system and spread to other organs. Jung and fellow civil engineering professor Brandon Boor have been the first to study nanoscale airborne particle formation indoors and compare it to outdoor atmospheric processes.
“To understand how airborne particles form indoors, you need to measure the smallest nanoparticles — down to a single nanometer. At this scale, we can observe the earliest stages of new particle formation, where fragrances react with ozone to form tiny molecular clusters. These clusters then rapidly evolve, growing and transforming in the air around us,” said Boor, Purdue’s Dr. Margery E. Hoffman Associate Professor in Civil Engineering.
In a “tiny house lab” — a dedicated residential lab space for indoor air quality research — Jung and Boor are using the latest industry-developed air quality instruments to track how household products emit chemicals that evaporate easily, called volatile chemicals, and generate the tiniest airborne nanoparticles.
Called the Purdue zero Energy Design Guidance for Engineers (zEDGE) lab, the tiny house has all the features of a typical home but is equipped with sensors for closely monitoring the impact of everyday activities on a home’s air quality. Jung led the design of the lab, which was built in 2020 as the first of its kind.
With this unprecedented level of detail and accuracy, Jung and Boor have made discoveries suggesting that many everyday household products used indoors may not be as safe as previously assumed.
Even though it’s yet to be determined how breathing in volatile chemicals from these products impacts your health, the two have repeatedly found that when fragrances are released indoors, they quickly react with ozone to form nanoparticles. These newly formed nanoparticles are particularly concerning because they can reach very high concentrations, potentially posing risks to respiratory health.
Jung and Boor believe these findings highlight the need for further research into indoor nanoparticle formation triggered by heavily scented chemical products.
“Our research shows that fragranced products are not just passive sources of pleasant scents — they actively alter indoor air chemistry, leading to the formation of nanoparticles at concentrations that could have significant health implications,” Jung said. “These processes should be considered in the design and operation of buildings and their HVAC systems to reduce our exposures.”
Pleasant scents from chemical products create air pollution inside your home
In a recently published paper, the pair found that scented wax melts, typically advertised as nontoxic because they are flame-free, actually pollute indoor air at least as much as candles.
Wax melts and other scented products release terpenes, the chemical compounds responsible for their scents. Since wax melts contain a higher concentration of fragrance oils than many candles, they emit more terpenes into indoor air.
It’s the terpenes in these products that rapidly react with ozone, triggering significant nanoparticle formation. In fact, the nanoparticle pollution from wax melts rivals that of candles, despite the absence of combustion. These findings highlight the need to study noncombustion sources of nanoscale particles, such as fragranced chemical products. Jung and Boor found in another study that essential oil diffusers, disinfectants, air fresheners and other scented sprays also generate a significant number of nanoscale particles.
But it’s not just scented products contributing to indoor nanoparticle pollution: A study led by Boor found that cooking on a gas stove also emits nanoparticles in large quantities.
Just 1 kilogram of cooking fuel emits 10 quadrillion particles smaller than 3 nanometers, which matches or exceeds what’s emitted from cars with internal combustion engines. At that rate, you might be inhaling 10-100 times more of these sub-3 nanometer particles from cooking on a gas stove indoors than you would from car exhaust while standing on a busy street.
Still, scented chemical products match or surpass gas stoves and car engines in the generation of nanoparticles smaller than 3 nanometers, called nanocluster aerosol. Between 100 billion and 10 trillion of these particles could deposit in your respiratory system within just 20 minutes of exposure to scented products.
Future work in the only lab of its kind
To continue learning more about chemical emissions and nanoparticle formation indoors, Jung and Boor are working with industry partners to test new air quality measurement instruments in Purdue’s tiny house lab before they are put on the market. Companies have been drawn to this lab because it’s a more realistic setting than chamber environments typically used for indoor air quality research and developing new products.
“When companies see top-tier research coming out of Purdue, they want to be part of it,” Jung said. “And if they have an innovative product, they want experts to push it to its limits.”
One of those instruments is a particle size magnifier—scanning mobility particle sizer (PSMPS) developed by GRIMM AEROSOL TECHNIK, a DURAG GROUP company. With this cutting-edge instrument, Jung and Boor can measure nanoparticles as small as a single nanometer as soon as they start to form.
Having a way to collect high-resolution data on the rate of new particle formation and growth indoors has allowed the pair to publish breakthrough studies comparing nanoscale particle emissions between indoor and outdoor atmospheric environments. Since indoor air quality is largely unregulated and less studied than outdoor air, these comparisons are important for understanding pollutant exposures and improving indoor environments.
Jung and Boor also use the tiny house lab to study how a range of other everyday household activities could impact a home’s air quality, such as hair care routines. Jung and her students have found that several chemicals, particularly cyclic volatile methyl siloxanes — which are ubiquitous in hair care products — linger in the air in surprising amounts during and after use. In a single hair care session at home, a person can inhale a cumulative mass of 1-17 milligrams of these chemicals.
Toxicologists will need to build upon these studies to find out exactly how harmful it could be to inhale complex mixtures of volatile chemicals and nanoscale particles indoors. As their research continues, Jung and Boor also hope their findings will improve how indoor air quality is monitored, controlled and regulated.
“Indoor air quality is often overlooked in the design and management of the buildings we live and work in, yet it has a direct impact on our health every day,” Boor said. “With data from the tiny house lab, we aim to bridge that gap — transforming fundamental research into real-world solutions for healthier indoor environments for everyone.”
Jung and Boor’s air quality research is largely funded by the National Science Foundation, the U.S. Environmental Protection Agency and the Alfred P. Sloan Foundation Chemistry of Indoor Environments program.
Papers
Flame-free candles are not pollution-free: Scented wax melts as a significant source of atmospheric nanoparticles Environmental Science & Technology Letters DOI: 10.1021/acs.estlett.4c00986
Real-time evaluation of terpene emissions and exposures during the use of scented wax products in residential buildings with PTR-TOF-MS Building and Environment DOI: 10.1016/j.buildenv.2024.111314
Rapid nucleation and growth of indoor atmospheric nanocluster aerosol during the use of scented volatile chemical products in residential buildings ACS ES&T Air DOI: 10.1021/acsestair.4c00118
The inside orf Pudue University's "tiny house lab" has various sensors and equipment to accurately and precisely measure pollutant emissions from common household activities in real time.
Purdue University assistant professor Nusrat Jung uses equipment in the "tiny house lab," which she designed to fill gaps in scientific understanding of indoor air quality. The lab, a dedicated residential lab space, is the first and only one of its kind.
Purdue University associate professor Brandon Boor led a study with surprising findings about how gas stove emissions compare to car exhaust. He conducted this research using the stove behind him in the "tiny house lab," which has all the features of a typical home but is equipped with sensors for closely monitoring the impact of everyday activities on a home’s air quality.
Together with a team of international clinical researchers, Professor Dr Oliver A. Cornely and Dr Rosanne Sprute from University Hospital Cologne have published the new global guideline for the diagnosis and treatment of Candida infections. This guideline establishes new standards for managing fungal infections, which affect millions of people worldwide every year, and was recently published in Lancet Infectious Diseases.
The new guideline contains detailed recommendations on the prevention, diagnosis and treatment of various forms of candidiasis – from superficial infections to life-threatening invasive infections – for clinicians, including innovative diagnostic procedures and the latest therapeutic approaches. Particular attention is paid to new challenges such as resistance to common antifungals and the increasing spread of Candida auris, a multi-resistant pathogen.
“With this guideline, we have taken an important step towards improving treatment for patients worldwide,” said Professor Cornely, head of the global initiative. Co-lead Dr Sprute added: “Our aim was to pool the expertise of a global network to provide doctors and healthcare professionals with a practical and scientifically sound tool.”
The document is the result of four years of intensive collaboration among more than one hundred experts from 35 countries. Supported by the expert associations ECMM (European Confederation of Medical Mycology), ISHAM (International Society for Human and Animal Mycology) and ASM (American Society for Microbiology), the initiator Oliver Cornely invited potential authors for the guideline based on speciality, geography, and gender. Six coordinators were appointed to ensure the structure of the guideline, assign topics, identify missing aspects and monitor progress.
The guideline has been endorsed worldwide by seventy six international expert associations as an important guide for practising physicians and meets the highest standards of quality and relevance to clinical care. “Our compilation is unprecedented and provides a basis for improving the treatment and chances of survival of affected patients worldwide,” said Cornely, underlining the significance of the work.
