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)
Tuesday, March 07, 2023
YOGIS KNOW THIS
Study finds perception of time linked to heartbeat
ITHACA, N.Y. – How long is the present? The answer, Cornell University researchers suggest in a new study, depends on your heart. They found that our momentary perception of time is not continuous but may stretch or shrink with each heartbeat.
The research builds evidence that the heart is one of the brain’s important timekeepers and plays a fundamental role in our sense of time passing – an idea contemplated since ancient times, said Adam K. Anderson, professor of psychology.
“Time is a dimension of the universe and a core basis for our experience of self,” Anderson said. “Our research shows that the moment-to-moment experience of time is synchronized with, and changes with, the length of a heartbeat.”
Time perception typically has been tested over longer intervals, when research has shown that thoughts and emotions may distort our sense time, perhaps making it fly or crawl. Such findings, Anderson said, tend to reflect how we think about or estimate time, rather than our direct experience of it in the present moment.
To investigate that more direct experience, the researchers asked if our perception of time is related to physiological rhythms, focusing on natural variability in heart rates. The cardiac pacemaker “ticks” steadily on average, but each interval between beats is a tiny bit longer or shorter than the preceding one, like a second hand clicking at different intervals.
The team harnessed that variability in a novel experiment. Forty-five study participants – ages 18 to 21, with no history of heart trouble – were monitored with electrocardiography, or ECG, measuring heart electrical activity at millisecond resolution. The ECG was linked to a computer, which enabled brief tones lasting 80-180 milliseconds to be triggered by heartbeats. Study participants reported whether tones were longer or shorter relative to others.
The results revealed what the researchers called “temporal wrinkles.” When the heartbeat preceding a tone was shorter, the tone was perceived as longer. When the preceding heartbeat was longer, the sound’s duration seemed shorter.
“These observations systematically demonstrate that the cardiac dynamics, even within a few heartbeats, is related to the temporal decision-making process,” the authors wrote.
The study also showed the brain influencing the heart. After hearing tones, study participants focused attention on the sounds. That “orienting response” changed their heart rate, affecting their experience of time.
“The heartbeat is a rhythm that our brain is using to give us our sense of time passing,” Anderson said. “And that is not linear – it is constantly contracting and expanding.”
The scholars said the connection between time perception and the heart suggests our momentary perception of time is rooted in bioenergetics, helping the brain manage effort and resources based on changing body states including heart rate.
The research shows, Anderson said, that in subsecond intervals too brief for conscious thoughts or feelings, the heart regulates our experience of the present.
“Even at these moment-to-moment intervals, our sense of time is fluctuating,” he said. “A pure influence of the heart, from beat to beat, helps create a sense of time.”
IMAGE: IN A NEW STUDY PUBLISHED IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY LETTERS, FLUORINATED HIGH-DENSITY POLYETHYLENE (HDPE) PLASTIC CONTAINERS — USED FOR HOUSEHOLD CLEANERS, PESTICIDES, PERSONAL CARE PRODUCTS AND, POTENTIALLY, FOOD PACKAGING — TESTED POSITIVE FOR PFAS.view more
CREDIT: UNIVERSITY OF NOTRE DAME
Researchers at the University of Notre Dame are adding to their list of consumer products that contain PFAS (per- and polyfluoroalkyl substances), a toxic class of fluorine compounds known as “forever chemicals.”
In a new study published in Environmental Science and Technology Letters, fluorinated high-density polyethylene (HDPE) plastic containers — used for household cleaners, pesticides, personal care products and, potentially, food packaging — tested positive for PFAS. Following a report conducted by the EPA that demonstrated this type of container contributed high levels of PFAS to a pesticide, this research demonstrates the first measurement of the ability of PFAS to leach from the containers into food as well as the effect of temperature on the leaching process.
Results also showed the PFAS were capable of migrating from the fluorinated containers into food, resulting in a direct route of significant exposure to the hazardous chemicals, which have been linked to several health issues including prostate, kidney and testicular cancers, low birth weight, immunotoxicity and thyroid disease.
“Not only did we measure significant concentrations of PFAS in these containers, we can estimate the PFAS that were leaching off creating a direct path of exposure,” said Graham Peaslee, professor of physics in the Department of Physics and Astronomy at Notre Dame and an author of the study.
It’s important to note that these types of containers are not intended for food storage, but there is nothing preventing them from being used for food storage at the moment. Although not all HDPE plastic is fluorinated, the researchers noted, it’s often impossible for a consumer to know whether a container has had that treatment. And indeed, Peaslee added, if substances like pesticides are stored in these containers, and then are used on agricultural crops, these same PFAS will get into human food sources that way.
In 2021 the EPA announced its PFAS Strategic Roadmap — promising to act on widespread exposure to PFAS. The plan includes developing a more comprehensive understanding of the health and environmental effects of PFAS exposure, preventing further contamination of air, land and water and addressing the need for cleanup of PFAS already in the environment.
PFAS is often used in association with stain- or water-resistant products. For the study, Peaslee and graduate student Heather Whitehead tested HDPE containers that were treated with fluorine to create a thin layer of a fluoropolymer, as a means to impart chemical resistance and improve container performance over long storage periods. While these materials generally stay in the container wall, the manufacturing process can generate lots of smaller PFAS molecules, which are not polymers. Experiments were designed to measure the ability of these chemicals to migrate from the container to samples of different foods and solvents.
Analysis of the containers found parts-per-billion levels of PFAS that could migrate into both solvents and food matrices in as little as one week.
“We measured concentrations of PFOA that significantly exceeded the limit set by the EPA’s 2022 Health Advisory Limits,” said Peaslee. “Now, consider that not only do we know that the chemicals are migrating into the substances stored in them, but that the containers themselves work their way back into the environment through landfills. PFAS doesn’t biodegrade. It doesn’t go away. Once these chemicals are used, they get into the groundwater, they get into our biological systems, and they cause significant health problems.”
Peaslee and Whitehead measured PFAS concentrations in olive oil, ketchup and mayonnaise that had been in contact with the fluorinated containers for seven days at various temperatures. Based on the amount found in the different food samples, the study estimates enough PFAS could be ingested through food stored in the containers to be a significant risk of exposure.
The University of Liverpool is leading a new collaborative research project to explore how the Gulf Stream affects the climate system through the transport of nutrients and carbon.
Funded by the Natural Environment Research Council (NERC) and US National Science Foundation (NSF), the £3.7 million project will use sensors located in the fast-flowing waters moving through Florida Straits and autonomous vehicles roaming the upper 2000m of the Atlantic basin to measure nutrient and carbon levels, and the amount of turbulence in the Gulf Stream.
This data will be used alongside the latest state-of-the-art ocean and climate models to find out more about how the Gulf Stream current affects the transport of nutrients and carbon and if it enhances or inhibits the uptake of carbon dioxide by the ocean.
Originating at the tip of Florida, the Gulf Stream is generally viewed to lead to milder winters in Europe through its role in transporting heat over the Atlantic basin. However, less is known about the role it plays in the strength and pattern of carbon uptake over the North Atlantic.
Professor Ric Williams, Chair in Ocean and Climate Sciences at the University of Liverpool and co-lead of the University of Liverpool’s Climate Futures research theme, will lead the programme.
He said: “We know that the Gulf Stream is important for supplying heat to higher latitudes, leading to a warmer European climate. However, we need to better understand the role of the Gulf Stream on the carbon cycle given that the ocean takes up nearly 25% of the extra carbon emitted to the atmosphere.
The prevailing view of how the ocean affects the uptake of carbon dioxide is often outdated and generally ignores the three-dimensional aspect of the ocean circulation. In contrast, we aim to test the viewpoint that the Gulf Stream helps determine the strength and pattern of carbon uptake over the North Atlantic.
“The natural carbon sinks in the ocean and land are thought to be becoming less effective in taking up carbon dioxide from the atmosphere, a key finding of the 2021 Intergovernmental Panel for Climate Change (IPCC) report. This ocean and land carbon uptake then ultimately affects how much carbon dioxide remains in the atmosphere and so affects how much our climate system continues to warm, including determining whether there is continued warming when we reach net zero.”
The four year programme supports a team of experienced and early career researchers from the University of Liverpool, the National Oceanography Centre, the University of Southampton, the British Antarctic Survey, the Scottish Association for Marine Science and the University of Miami augmented by project partners at Massachusetts Institute of Technology, University of Rhode Island and Woods Hole Oceanographic Institution in the USA, and from research institutes in Bergen in Norway, Brest in France and Texel in the Netherlands.
Novel porous materials are ideal for metal-air batteries, researchers report
IMAGE: IN A REVIEW OF THE CURRENT STATE OF STRUCTURALLY DIVERSE METAL-ORGANIC FRAMEWORKS AND COVALENT ORGANIC FRAMEWORKS WITH UNIQUE ELECTRICAL PROPERTIES, RESEARCHERS HAVE FOUND THEY OFFER “GREAT POTENTIAL” FOR FACILITATING THE NECESSARY REACTIONS FOR METAL-AIR BATTERIES.view more
CREDIT: NANO RESEARCH ENERGY, TSINGHUA UNIVERSITY PRESS
Sustainable energy solutions cannot be pulled out of thin air. However, combining air with metal and other frameworks may pave the way for environmentally friendly energy conversion and storage, according to a research team based in China.
They published their review of novel porous materials — called metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) — and their potential to advance metal-air batteries on 03 March in Nano Research Energy.
The porous crystal material frameworks comprise various arrangements of bonded materials that can induce desired properties, including the ability to accelerate reactions between oxygen and metals for energy conversion and storage. Their diverse arrangements facilitate flexibility, with high porosity and surface area, allowing for the best chance of the necessary reactions. Their derivates, or products derived from the frameworks, also enhance previously insufficient electronic conductivity and improve chemical stability.
But their advancement has been limited by inadequate conductivity and stability, according to co-corresponding author Tao Wang, professor, Centre for Hydrogenergy, College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics.
“Metal-air batteries, with high specific energy, moderate pricing, high safety and environmental friendliness, are the most promising candidate for energy storage and conversion,” Wang said. “At present, however, metal-air batteries involve a complex catalytic process of gas-liquid-solid phases, making it difficult to deeply understand the mechanism of discharge and recharge processes.”
Wang also noted that some of the MOF and COF arrangements have slow reaction kinetics, meaning an efficient catalyst is needed both to reduce potential conversion challenges and improve the battery’s life cycle.
To better understand how to control benefits — and mitigate the challenges — of the frameworks and their derivates, the researchers reviewed the current available scientific literature. Among other insights, they found that the frameworks exhibit a unique molecular structure that enables high porosity with uniform distribution of catalytic sites, meaning their reactions can be more predictable than with other porous materials.
“By systematically studying the effects between organic components and catalytic active centers of MOFs and COFs, we can gain a theoretical basis for us to select and synthesize the desired framework catalysts in the future,” Wang said. “We can also better understand the local microenvironment in MOFs and COFs and how it impacts the overall catalytic effect.”
Wang and the team recommend further study of how to better prepare functionalized MOFs and COFs based on their reaction mechanism; of hybrid MOFs and COFs; and of the composition control and morphology of MOF and COF derivates. They also recommend developing more advanced techniques to detect the vibration signals of molecules on the electrode surface and observe the conversion process to fully elucidate the relationship between the structure and the performance.
“By comprehensively reviewing the advantages, challenges and prospects of MOFs and COFs, we hope that the organic framework materials will shed more profound insights into the development of electrocatalysis and energy storage in the future,” Wang said.
Contributors from Nanjing University of Aeronautics and Astronautics include co-corresponding authors Hairong Xue and Jianping He and co-authors Yunyun Xu, Xijuan Li, Peng Li, Tengfei Zhang, and Kun Chang. Xiaoli Fan from Nanjing Institute of Technology’s School of Materials Science and Engineering is also a co-author.
The National Defense Technology Innovation Special Zone Spark Project, the Natural Science Foundation of Jiangsu Province and a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions funded this research.
Nano Research Energy is launched by Tsinghua University Press, aiming at being an international, open-access and interdisciplinary journal. We will publish research on cutting-edge advanced nanomaterials and nanotechnology for energy. It is dedicated to exploring various aspects of energy-related research that utilizes nanomaterials and nanotechnology, including but not limited to energy generation, conversion, storage, conservation, clean energy, etc. Nano Research Energy will publish four types of manuscripts, that is, Communications, Research Articles, Reviews, and Perspectives in an open-access form.
SciOpen is a professional open access resource for discovery of scientific and technical content published by the Tsinghua University Press and its publishing partners, providing the scholarly publishing community with innovative technology and market-leading capabilities. SciOpen provides end-to-end services across manuscript submission, peer review, content hosting, analytics, and identity management and expert advice to ensure each journal’s development by offering a range of options across all functions as Journal Layout, Production Services, Editorial Services, Marketing and Promotions, Online Functionality, etc. By digitalizing the publishing process, SciOpen widens the reach, deepens the impact, and accelerates the exchange of ideas.
VIDEO: WHITESPOTTED EAGLE RAYS “CRUNCHING” ON CLAMS IN A LARGE OUTDOOR TANK WITH CLAMS HOUSED WITHIN A VARIETY OF ANTI-PREDATOR MATERIALS.view more
CREDIT: FAU HARBOR BRANCH OCEANOGRAPHIC INSTITUTE
According to NOAA Fisheries, more than 80 percent of marine aquaculture production in the United States consists of bivalve mollusks such as oysters, clams and mussels. However, it’s not just humans who enjoy eating these shellfish, so do marine rays. They like to “crunch” on clams, which can sometimes take a big bite out of clammers’ profits.
Part of the process of culturing hard clams (Mercenaria mercenaria) involves deploying them in submerged bottom leases in the marine environment where clams can grow to market size. When deployed onto the clam lease, clammers incorporate a variety of anti-predator materials to protect their product, such as woven mesh netting and/or additional mesh, plastic or wire covers.
However, the effectiveness of these materials against highly mobile predators like rays has not been experimentally tested. Some rays, like the whitespotted eagle ray (Aetobatus narinari), are equipped with strong jaws, plate-like teeth and nimble pectoral fins, which make them formidable and highly maneuverable predators of clams.
Inspired by clammer reports of damaged grow-out gear presumably caused by rays, researchers from Florida Atlantic University’s Harbor Branch Oceanographic Institute in collaboration with Mote Marine Laboratory, assessed the ability of the whitespotted eagle ray to interact with clams housed within a variety anti-predator materials.
Using aerial and underwater videos, researchers assessed the rays’ responses to anti-predator materials placed within a large outdoor tank. They examined their interactions with a control plot (unprotected clams), clams inside polyester mesh clam bags (dipped in a latex net coating), and with clams under high density polyethylene (HDPE) netting or chicken wire cover netting. After the completion of each trial, researchers assessed the number of crunched clams and frequency of visits to the various randomized patches.
Results, published in the journal Aquaculture Environment Interactions, showed that rays were capable of consuming clams through bags. However, anti-predator treatments reduced clam mortality four- to tenfold compared to control plots. Double-layered (bags with cover netting) treatments had the lowest clam mortality, highlighting the utility of this type of protection in limiting ray impacts.
“Based on our findings, many of the current anti-predator grow-out strategies used in the hard clam shellfish aquaculture industry appear capable of reducing predation by large predators like whitespotted eagle rays,” said Matt Ajemian, Ph.D., senior author, an associate research professor and director of the Fisheries Ecology and Conservation Lab at FAU Harbor Branch. “In particular, bag treatments with cover nettings achieved the highest clam survival rates, although it is important to note that this did not appear to completely deter rays from interacting with the gear.”
Observations from the study suggest that rays appear capable of interacting with aquaculture gear for prolonged periods, potentially diverting them from other natural feeding habitats such as sand and mud flats.
“These habitat associations could expose these sensitive animals to other risks, although we are just beginning to understand them and admittedly have a lot more to learn,” said Brianna Cahill, corresponding author, an FAU Harbor Branch marine science and oceanography graduate, and a research technician at Stony Brook University.
Throughout the course of the study, researchers confirmed that rays are capable of uprooting and manipulating hard clam aquaculture gear, as they moved treatments and trays within the tank throughout the course of the experiments.
“Contrary to what we expected, rays did not prefer control plots (mimicking natural conditions) over treatment plots with anti-predator gear,” said Cahill. “This suggests a real possibility that these rays are interacting with shellfish aquaculture gear in the wild, as suggested by our clamming industry partners.”
Among the variety of interactions researchers observed between rays and the treatments included using their lower dental plate to dig through sediment to access clams in the control plots and to move the gear (clam bags, cover netting and trays). In addition, because HDPE netting appeared to snag on the rays’ lower dental plate, it caused them to displace the HDPE cover netting more than chicken wire cover netting.
Chicken wire has been used in Florida to deter predation from rays because of its strength. Research has suggested that the electric field of the metal can be detected by elasmobranchs such as rays and sharks, potentially acting as an over-stimulant and thus, a deterrent.
“Given the frequency of interactions we observed with chicken wire in our experiment, we question whether chicken wire is a deterrent, an attractant or neutral, as it may not have a powerful enough signal to influence the rays,” said Ajemian. “Still, we have more questions than we started with, and look forward to investigating this further with other species and deterrent types.”
Study co-authors are Kayla L. McCulloch, Rosenstiel School of Marine and Atmospheric Science, University of Miami; Breanna C. DeGroot, research coordinator, Fisheries Ecology and Conservation Lab at FAU Harbor Branch; and Kim Bassos-Hull, senior biologist at Mote Marine Laboratory.
Funding for these experiments was provided by the Aquaculture Specialty License Plate Fund (AWD-002112) administered by the Harbor Branch Oceanographic Institute Foundation.
- FAU -
About Harbor Branch Oceanographic Institute: Founded in 1971, Harbor Branch Oceanographic Institute at Florida Atlantic University is a research community of marine scientists, engineers, educators and other professionals focused on Ocean Science for a Better World. The institute drives innovation in ocean engineering, at-sea operations, drug discovery and biotechnology from the oceans, coastal ecology and conservation, marine mammal research and conservation, aquaculture, ocean observing systems and marine education. For more information, visit www.fau.edu/hboi.
About Florida Atlantic University: Florida Atlantic University, established in 1961, officially opened its doors in 1964 as the fifth public university in Florida. Today, the University serves more than 30,000 undergraduate and graduate students across six campuses located along the southeast Florida coast. In recent years, the University has doubled its research expenditures and outpaced its peers in student achievement rates. Through the coexistence of access and excellence, FAU embodies an innovative model where traditional achievement gaps vanish. FAU is designated a Hispanic-serving institution, ranked as a top public university by U.S. News & World Report and a High Research Activity institution by the Carnegie Foundation for the Advancement of Teaching. For more information, visit www.fau.edu.
IMAGE: RESEARCH OUT OF THE WVU SCHOOL OF PUBLIC HEALTH FOUND THAT DRINKING, DRUG USE AND DRIVING INCREASED AMONG PATIENTS BEING TREATED FOR MOTOR VEHICLE COLLISION INJURIES AT A WEST VIRGINIA TRAUMA CENTER DURING THE COVID-19 PANDEMIC.view more
CREDIT: WVU ILLUSTRATION/AIRA BURKHART
One West Virginia trauma center saw an uptick in alcohol and drug use by patients treated for motor vehicle collision injuries during the COVID-19 pandemic, according to a West Virginia Universitystudy. More specifically, researchers found patients were using a greater number of drugs, including cannabinoids, opioids and stimulants during the pandemic than prior to its onset.
The study was published in Injury Epidemiology, an online peer-reviewed journal focusing on injury prevention and control. Toni Marie Rudisill, assistant professor in the WVU School of Public Health, led the research team that included pre-med student Lucie Steinmetz, of Moon, Pennsylvania, and Dr. James Bardes, assistant professor in the Department of Surgery’s Division of Trauma, Acute Care Surgery and Surgical Critical Care.
The patients were treated at Jon Michael Moore Trauma Center in Morgantown, one of two Level 1 trauma centers in West Virginia.
As stress levels increased at the onset of the COVID-19 pandemic, so did the use of alcohol and drugs among drivers in urban areas, according to several studies. That prompted Rudisill and her team to see if the same held true for rural areas, particularly the Mountain State.
“It was important to determine what was happening here in West Virginia and if we were following the same trend,” Rudisill said. “Our findings may be generalizable to West Virginia. However, we are unsure if our findings would be generalizable to other rural areas.”
With support from the West Virginia Clinical and Translational Science Institute, housed at WVU, and funding from the National Institute of General Medical Sciences of the National Institutes of Health, the team set out to analyze and compare records of patients ages 18 and older who were treated for motor vehicle-related injuries during two time frames: pre-COVID-19 period — Sept. 1, 2018, to March 15, 2020, and COVID-19 period — March 16, 2020, to Sept. 30, 2021.
Throughout the study period, 1,465 patients received treatment. Patients were given a blood test to determine whether they had been using alcohol, while a urine test was conducted to see if drugs were present in the patients’ systems. Drugs included in the testing panel were cannabinoids, opioids, stimulants and depressants.
Any amount of alcohol was considered a positive test. Patients were considered drug positive if one or more non-alcohol drugs were detected. The discovery of one or more non-alcohol drugs and any amount of alcohol was deemed drug and alcohol positive. Drugs received as part of pre-hospital care were excluded from analyses to avoid misclassification of an individual who may have received the medication as part of post-collision care.
“Given our state’s rurality, it can take quite a bit of time to transport severely injured patients from the scene of a crash to a trauma center,” Rudisill said. “Patients may receive medication from emergency medical services as part of their care during transport. However, drug and alcohol tests are performed on patients when they arrive at the trauma center. It is entirely possible that a patient may have consumed an opioid before the crash, but then received one as part of their care during transport to the trauma center. For that reason, those individuals’ results would be excluded from the analysis as we would not be able to determine if the opioids in their system were taken before the crash or administered by EMS on the way to the trauma center.”
The study found that the number of drugs patients tested positive for was 31% greater during the COVID-19 period. Stimulant and opioid use significantly increased among treated patients and cannabinoid use increased marginally, while depressant use decreased over the study period.
The majority of the patients, 57%, were male and between the ages of 20 and 45. Overall, 84% were drivers of the vehicles and 72% were wearing seatbelts. Most of the crashes occurred during weekdays.
Researchers concluded that, although further studies could investigate whether drug and alcohol use among drivers in West Virginia changed after September 2021, public health interventions may be needed in the state to curb the activity.
“Getting people to stop using drugs and/or alcohol and then driving is a complex issue,” Rudisill said. “Reducing this behavior in a population often requires a combination of educational, environmental, behavioral and policy approaches to be effective.”
WVCTSI Background
WVCTSI is funded by an IDeA Clinical and Translational grant from the National Institute of General Medical Sciences (U54GM104942) to support the mission of building clinical and translational research infrastructure and capacity to impact health disparities in West Virginia.
IMAGE: MICROGRAVITY CONDITIONS WERE GENERATED DURING A SHORT PARABOLIC FLIGHT —WITH FIFTEEN PARABOLAS— IN AN AEROBATIC FLIGHT CONDUCTED WITH THE MUDRY CAP10 AIRCRAFT.view more
CREDIT: UNIVERSITY OF BARCELONA
Space travel has always tested the human body by the effects of the new conditions of altered gravity on biological systems. It has long been known that continuous exposure to microgravity conditions human physiology and causes effects that compromise muscular, sensory, endocrine and cardiovascular functions. But is it also risky to be exposed to altered gravity for short periods of time?
Now, a paper published in the journal Acta Astronauticaexamines the effects on the human immune system of microgravity generated by a parabolic flight. After a short exposure to altered gravity, there were no significant changes in the defensive capacity of blood cells in the volunteers who took part in the study. In addition, the study found no evidence of aggregation processes in erythrocytes —the cells that transport O2 and CO2 to the cardiovascular system— after the parabolic flight.
Space travel is the ideal scenario to study the effect of microgravity on the human body. These trips make it possible to study the consequences of long-term exposure to microgravity on different astronauts simultaneously, but they require a high cost in terms of time, funding and infrastructure. Without leaving the Earth's atmosphere, it is also possible to simulate simulated gravity conditions on different platforms. For example, through parabolic flights in aircraft, which make it possible to study the effect of altered microgravity in the short term —even for a few seconds— at an affordable cost.
One of the most vulnerable physiological systems to any change in environmental conditions is the immune system, and this is explained by its great plasticity and responsiveness to internal and external imbalances. In the scientific literature, there are still no conclusive results on the immune response to short exposure in flights with altered gravity, and in some cases the conclusions are even contradictory.
In this study, the team analysed the response of the immune system to short exposure to microgravity based on several parameters: erythrocyte and leukocyte counts, haemoglobin concentration, phagocytic capacity and oxidative metabolism.
"The results reveal that the human blood samples’ exposure to altered gravity conditions in parabolic flight did not involve negative effects in relation to samples that were left parallelly on the ground during the experimental study. There are also no significant changes in peripheral blood cell counts", says Jordi Petriz (IGTP).
"Except for the monocytes —a type of leukocyte— no significant differences have been observed in the functionality of immune cells in terms of either their oxidative metabolism or their phagocytic capacity", says researcher Abril Gorgori-González (UB). "Hypothetically, if there were changes in the functionality of leukocytes when exposed to an altered gravity, the immune function and defence against external infections or tumour processes would also be compromised”.
The team has applied the technique of flow cytometry with acoustic focusing with little manipulation of the volunteers' blood samples. According to the authors, the sample limitation typical of acrobatic flight studies —with logistical constraints— does not allow general conclusions to be drawn. Therefore, the goal now is to continue research on the human immune system with other microgravity simulation platforms to study physiological alterations, avoid complications and anticipate risk situations.
Space tourist warning
Space tourism is an activity of great economic interest for some business sectors. However, one of the main differences between space tourists and astronauts is the physical and psychological preparation prior to the trip.
"Altered gravity or the constant lack of gravity is one of several changes in the environment faced by these space travellers. The human body has evolved under the conditions of Earth's gravity and is not adapted to the absence of this attractive force. In space travel, other factors such as ionising radiation, constant noise, isolation, confinement, a total distortion of circadian rhythms and short exposure to extreme temperatures during the return to the atmosphere have to be considered", the experts warn.
"Long-term metabolic, osteoporosis and ophthalmological problems have also been described. Although the effect of space travel on untrained space travellers has not been studied, it is possible that all the stressors of the physical environment could negatively affect the health of space tourists. Therefore, for the time being, 'outer space visits' are designed to be of short duration", the team concludes.
The volunteers' blood samples were exposed to altered gravity conditions in parabolic flight.
These parabolic flights with an aerobatic plane —a pioneering method in the world, developed in Catalonia— were operated by the Aeroclub Barcelona-Sabadell.
The study has applied the technique of flow cytometry with acoustic focusing with little manipulation of the volunteers' blood samples.
The human blood samples’ exposure to altered gravity conditions in parabolic flight did not involve negative effects in relation to samples that were left parallelly on the ground during the experimental study.
