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)
Thursday, September 19, 2024
Do cats know their own dimensions and use that knowledge to squeeze through tight openings?
An ethologist at Eötvös Loránd University has tested cats in their home environments to better understand their awareness of their own size and dimensions. In his study published in iScience, Péter Pongrácz conducted experiments with cats and their owners regarding the feline's awareness of their own body size and shape.
Anecdotal evidence has shown that the common housecat is able to slip through extremely small openings and conform itself into small odd shapes such as flower vases. These abilities have led some to describe their pets as liquid entities, able to take on any shape or form.
In this new study, Pongrácz wondered about the processing in the cat's mind as it sized up an opening or container, perhaps wondering if it could fit through, or get inside of it. To that end, Pongrácz devised experiments to carry out in his lab.
Unfortunately, he soon found that cats, unlike the dogs he has worked with in the past, were not willing to work with him in the lab environment. Undeterred, he searched for and found 30 cat owners who allowed him to come into their homes to carry out his experiments.
Pongrácz placed thick pieces of cardboard into doorframes between rooms, fully blocking them—each had a hole in it, which the cat could climb through. The cats were tested by putting them on one side of the cardboard and the owners coaxed them to come through the hole. The size of holes varied by height and width, and each cat was invited to come through the barrier under a variety of circumstances.
The illustration in the survey to help measure some of the cat’s size parameters. Credit: iScience (2024). DOI: 10.1016/j.isci.2024.110799
Pongrácz found that most of the cats began to hesitate when confronted with a hole that had a height that appeared too small to allow them passage. This was not the case regarding width—they would give it a go no matter how narrow the hole.
Pongrácz also found that if a cat had made up its mind to try to get through the hole, it was almost always unwilling to give up until it succeeded, regardless of the amount of work involved in shimmying through.
More information: Péter Pongrácz, Cats are (almost) liquid!—Cats selectively rely on body size awareness when negotiating short openings, iScience (2024). DOI: 10.1016/j.isci.2024.110799
Polar bears found to have diverged from brown bears just 70,000 years ago
Credit: Unsplash/CC0 Public Domain
A team of molecular ecologists at the University of Copenhagen, in Denmark, has found that polar bears developed unique features that allowed them to survive in a harsh, cold environment just 70,000 years ago.
In their study published in the journal BMC Genomics, the group analyzed the genomes of more than 100 polar bears, another 100 brown bears and a pair of fossilized polar bears to learn more about the timeline involved in the development of characteristics such as white fur and the ability to subsist on a diet high in cholesterol.
Prior research has shown that polar bears are closely related to brown bears but until now, it was not known when the two species diverged. In this new study, the team in Denmark set themselves the task of finding the answer.
Some of the main differences between brown and polar bears are their fur color, of course, but also their fur types. Brown bears have one layer of fur, polar bears have two—an undercoat of downy fur that helps them stay warm and an overcoat that helps them stay dry. Polar bears have also developed the ability to eat meat containing a lot of blubber. If brown bears ate such a lipid-rich diet, they would develop heart disease and die young.
To learn more about when the two species diverged, the team looked at the genomes of both types of bears, most specifically at those genes involved in fur type and color and cardiovascular functions.
Geographic localities of the polar and brown bears included in this study. CWL shows the bears that were used in the study by Castruita, Westbury, and Lorenzen. Stars indicate the two Late Pleistocene polar bears. Credit: BMC Genomics (2024). DOI: 10.1186/s12864-024-10617-3
By comparing the genomes of 119 polar bears, 135 brown bears and two fossilized polar bears, the researchers found differences going back approximately 70,000 years, suggesting that polar bears have developed their unique characteristics much more recently than previously thought.
More specifically, the team found seven genes related to polar adaptation, four of which were fixed alleles in the polar bears. The comparison also showed that divergence was more gradual than previously thought.
The research team concludes that the gene differences associated with polar bear adaptions may have been influenced by bears living during the end stages of the last ice age.
More information: Yulin Sun et al, Late Pleistocene polar bear genomes reveal the timing of allele fixation in key genes associated with Arctic adaptation, BMC Genomics (2024). DOI: 10.1186/s12864-024-10617-3
(a) Worshippers in the Salat al Jama’ah are positioned in parallel rows behind the imam, and women are separated from men by a partition or other means. (b) The prayer consists of repetitive units (Rak’ah). Images adapted from pngtree.com. Credit: Philosophical Transactions of the Royal Society B: Biological Sciences (2024). DOI: 10.1098/rstb.2023.0162
Sharing stories over a cup of coffee; dancing in a group; cheering a football game in a crowd: these everyday rituals are among many different types of shared experiences that help humans develop social cohesion.
UConn researchers are studying another way humans connect: through synchronous movement or chanting, and Mohammadamin Saraei, a graduate student in the Department of Psychological Sciences, says we can see examples of the phenomenon everywhere around us, and throughout history in many cultures and religions.
After years of research, we now know that synchrony enhances social cohesion, creates a shared identity, boosts prosocial behavior, builds trust, and even contributes to our overall well-being.
But what makes this group-level synchrony happen? Saraei and co-authors Alexandra Paxton, assistant professor in the Department of Psychological Sciences, and Dimitris Xygalatas, associate professor in the Department of Anthropology, have detailed their findings in Philosophical Transactions of the Royal Society B.
The researchers studied synchrony during a religious ritual at the UConn Islamic Center, called Salat al Jama'ah, where more than 200 worshipers gathered for evening prayer.
They wanted to determine which aspects of the ritual were most impactful for creating synchrony, so they recruited participants who agreed to wear a comfortable device to measure physiological data like heart rate, breathing, and posture, and another device to measure the position of the participants throughout the prayer.
Saraei says that each day there are five rounds of prayer that Muslims are advised to do, and ideally with others as a community. To emphasize the community aspect, the researchers timed their study during the holy month of Ramadan, when Muslims fast during daylight hours and are likely to pray in larger group settings.
"We are very appreciative of Muslim students at UConn because it was difficult to participate in this study, especially considering we gathered this data during Ramadan, when they were fasting for 14 hours or so, but they were very cooperative and this study would not have been possible without them," says Saraei.
For the ritual, worshipers gather for the group prayer, and men are encouraged to line up closely behind the leader (imam), women usually gather behind a partition, and everyone faces the same direction—qibla, or the direction of Islam's most holy site in Mecca. The imam leads a cycle of prayers which include coordinated sequences of bowing and prostrating movements.
The results showed that, beyond impacts from worshippers around an individual, the researchers discovered the important role of the leader in creating synchrony and its physiological impacts, like synchronization of the participants' heart rates.
"This study shows us the important role of a leader in a community. Having a leader is a double-edged sword. This role can either be beneficial or harmful—because if you have a bad leader, they might create a toxic environment for everyone, like in a cult. But if you have a good leader, they can foster a community that helps everyone grow," Saraei says.
He says another important aspect of creating synchrony was the effect of proximity the worshipers had to the imam—the closer to the imam, the stronger the effect.
"Worshipers are strongly advised to go to the first lines behind the imam. We don't know the religious reasons behind it, but, interestingly, it is connected to the synchrony measures we have too," he says.
"I think one of the most important findings of this study was that if you are closer to that center of synchrony, you will get more synchronous, even physiologically in your heart rate, and there seems to be a ripple effect to the lines behind."
This ripple effect is likely due to the auditory-visual information that worshipers receive, says Saraei. During the prayer, people are looking down, therefore they can see their nearest neighbors in their peripheral vision, and this seems to help with coordinating movements.
"They hear the imam, but some of them do not see him, and there is a kind of two-way effect of synchrony. On one hand, you're seeing your neighbors, and this is one of your major sources of information, but on the other hand, you're affected from a longer distance by the imam."
Beyond religious settings, Saraei says Xygalatas's research group is also looking at the role synchrony plays in political events like debates or rallies.
"The way people chant or clap for the president, these gestures all affect social cohesion. Another example is with soldiers marching, which is no use in today's battlefields, but marching still makes sense because it helps create that bond you need on the battlefield."
Saraei is currently analyzing other positive health benefits of synchronous prayer by looking at heart rate variability (HRV) during prayer.
"Another interesting finding in my current analysis is the increase in HRV during Islamic collective prayer, suggesting its positive effects on well-being and stress reduction."
He says HRV is an indicator of things like reduced stress, a greater sense of well-being, and a healthy immune system. Saraei also has plans to investigate how the number of participants impacts synchrony and the potential impacts of virtual versus in-person participation.
Saraei says this study shows some of the mechanisms underlying synchrony for grounding and creating social interactions and cohesion. This is important because synchrony is a key aspect of our social lives.
"Synchrony is all around us, subtly shaping our connections and experiences," says Saraei. "Once you recognize it, you begin to see it everywhere, woven into the fabric of daily life—bringing us together in ways we often take for granted."
More information: Mohammadamin Saraei et al, Aligned bodies, united hearts: embodied emotional dynamics of an Islamic ritual, Philosophical Transactions of the Royal Society B: Biological Sciences (2024). DOI: 10.1098/rstb.2023.0162
The Max Forest scenario in the context of the shared socioeconomic pathways (SSPs). Credit: Biogeosciences (2024). DOI: 10.5194/bg-21-3883-2024
The side effects of large-scale forestation initiatives could have serious consequences for water availability, a pioneering study has found.
The research, led by scientists at the University of Sheffield in collaboration with NCAR, WWF and University of Washington, has raised significant concerns about the potential unintended impacts of large-scale forest expansion as a nature-based solution to climate change.
Published in Biogeosciences, the study revealed how expanding forest cover—while beneficial for capturing carbon dioxide—may lead to water scarcity and impact water security in some of the world's most vulnerable regions. Central Africa, a region with low adaptive capacity to climate change, could see water availability reduced by 15%
The study found that large-scale forestation could result in a surface cooling of up to 2°C at low latitudes by 2100, driven by a 10% increase in evaporative cooling. However, this cooling effect comes with trade-offs.
Building on previous work examining the atmospheric and radiative effects of forest expansion, this study focuses on the implications for water availability. The research found that in certain regions, particularly in the tropics, plant water stress more than doubles when forest expansion is implemented, raising concerns about the feasibility of these initiatives and their potential to compromise water security.
This reduced water availability could negatively impact agriculture and food production, particularly in regions reliant on groundwater and rivers.
Dr. James King, from the University of Sheffield's School of Biosciences and lead author of the research, said, "Our findings suggest that large-scale forest expansion plans may have more complex side-effects than previously thought if they are realised in the next few decades.
"While forestation can contribute to local cooling, the increased water demand could have serious consequences for water supply, especially in tropical and subtropical grassland areas. This calls into question the viability of forest expansion as a one-size-fits-all solution for climate change mitigation.
"We argue that while 'nature-based solutions' such as forest expansion are important and valuable tools in the fight against climate change, they need to be stress-tested using simulations to uncover potential negative side effects. This research highlights that relying on a single mitigation strategy is risky, and there is no substitute for reducing greenhouse gas emissions."
Dr. Maria Val Martin, University of Sheffield UKRI Future Leaders Fellow and senior author of the study, said, "Our study shows that large-scale forestation can offer regional cooling benefits and contribute to climate change mitigation, but it also has trade-offs. Expanding forests enhances evaporative cooling and lowers temperatures, but it also doubles water demand in some tropical regions, raising concerns about water availability in the future. It underscores the importance of carefully considering the biophysical impacts of reforestation and afforestation strategies, in addition to their CO2 removal potential."
Using advanced computer models simulating the Earth's land, atmosphere, and oceans, the researchers analyzed the global effects of current forest expansion plans. Beyond capturing and storing carbon, trees also significantly increase water transfer from soils into the atmosphere. While this has a cooling effect on the Earth's surface, it can also dry soils and rivers, particularly in tropical and subtropical regions, which may affect local food and water security.
The study comes at a time when tree planting initiatives are gaining momentum worldwide as an easy-to-understand and widely promoted solution to climate change.
The research group's next steps include investigating how forest expansion might be affected by wildfires in a warming world, as well as examining the consequences of wetland restoration for climate mitigation. The team is also studying how combining different climate strategies may affect air quality, particularly in the UK.
More information: James A. King et al, Global and regional hydrological impacts of global forest expansion, Biogeosciences (2024). DOI: 10.5194/bg-21-3883-2024
Discrepancies seen between young people's preferred, actual sources of contraceptive info
by Lori Solomon
SEPTEMBER 18, 2024
There are discrepancies between preferred and actual sources of contraceptive information for U.S. adolescents and young adults (AYA), according to a research letter published online Sept. 13 in JAMA Network Open.
Elizabeth Pleasants, Dr.P.H., from the University of California, Berkeley, and colleagues examined AYAs' preferred and actual sources of contraceptive information and assessed associations with reporting sufficient contraceptive information. The analysis included data from the online 2023 Thanks, Birth Control Survey (1,150 AYAs aged 15 to 29 years).
The researchers found discrepancies between AYAs' preferred and actual sources of contraceptive information and variations by age. Clinicians were the most commonly preferred source (68% among those younger than 18 years, 84% among 18- to 24-year-olds, and 87% among 25- to 29-year-olds). However, clinicians were less commonly the actual sources (33% among those younger than 18 years, 43% among 18- to 24-year-olds, and 50% among 25- to 29-year-olds).
Websites were reported more often as a preferred rather than actual source among older participants (36 versus 18% among 18- to 24-year-olds and 38 versus 17% among 25- to 29-year-olds). Social networking sites were less commonly preferred (6% among those younger than 18 years, 12% among 18- to 24-year-olds, and 10% among 25- to 29-year-olds), but were the second most common actual source for respondents ages 18 years and older (28% among 18- to 24-year-olds and 18% among 25- to 29-year-olds).
"Clinician engagement in online health education may be one strategy to help AYAs access preferred contraceptive information," the authors write.
More information: Elizabeth Pleasants et al, Adolescents and Young Adults' Sources of Contraceptive Information, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.33310
Study explores metabolic disruptions in Artemisia annua mutant strain
by TranSpread
SEPTEMBER 18, 2024
GSTs developmental defects in Artemisia annua lead to dramatic metabolic changes. Credit: Horticulture Research (2024). DOI: 10.1093/hr/uhae174
Artemisia annua is celebrated for its production of artemisinin, a powerful antimalarial agent. Although its glandular secretory trichomes have been the focus of extensive research, a complete understanding of their metabolic processes remains elusive. Previous studies have primarily centered on artemisinin, often overlooking other crucial metabolic pathways. Addressing these knowledge gaps is crucial for unlocking new therapeutic potentials within this medicinal plant.
Led by Shanghai Jiao Tong University researchers and published in Horticulture Research, the study explores the metabolic disturbances of a mutant strain of Artemisia annua, designated as TRICHOME DEVELOPMENTAL DEFECTS 1 (tdd1). This mutant displayed impaired glandular secretory trichome (GST) functionality, severely compromising artemisinin production. Utilizing integrated multi-omics profiling, the researchers identified complex metabolic disruptions, offering fresh perspectives on plant secondary metabolism.
The study analyzed the tdd1 mutant, which displayed pronounced defects in GSTs, crucial for artemisinin biosynthesis. In both young and mature leaves, artemisinin and its precursors were nearly undetectable, highlighting a significant disruption in the metabolic pathway. Through advanced Liquid Chromatography-Mass Spectrometry (LC–MS) and Gas Chromatography-Mass Spectrometry (GC–MS) analyses, 836 metabolites were identified, including flavonoids and terpenoids, many of which were absent in the mutant.
The research revealed key differences in the Mevalonate Pathway (MVA) and (Methylerythritol Phosphate Pathway) MEP pathways, with minimal expression of GST-specific genes linked to artemisinin biosynthesis. These findings underline the broader metabolic impact of GST defects and underscore their importance in secondary metabolite synthesis. The study demonstrates how multi-omics approaches can decipher complex metabolic interactions, enhancing our understanding of plant metabolism.
Dr. Ling Li, one of the study's researchers, stated, "This research unravels the complex metabolic network within Artemisia annua, spotlighting the vital role of glandular secretory trichomes. Identifying specific genes responsible for artemisinin deficiency in the tdd1 mutant lays a crucial foundation for future studies aimed at boosting antimalarial drug production."
The insights from this study hold significant potential for enhancing antimalarial drug production by targeting specific metabolic pathways in Artemisia annua. Deciphering the genetic and metabolic framework of GSTs can lead to refined cultivation techniques and genetic modifications that enhance artemisinin yields.
Additionally, this research opens avenues for exploring other valuable secondary metabolites in A. annua, potentially leading to the discovery of new medicinal compounds beyond artemisinin.
More information: Wei Qin et al, Integrated multi-omics profiling reveals a landscape of dramatic metabolic defect in Artemisia annua, Horticulture Research (2024). DOI: 10.1093/hr/uhae174
* Berta Fanta, 1865–1918. First woman graduate of Karl University in Prague, at that time called the Charles-Ferdinand University.* His father Hermann, desperate for his son to get a practical job, arranged several interviews to become an insurance agent and it’s said that the frustrated fledgling physicist even tried his hand at selling policies for a few months.
* And write the first ever sci-fi novel!* The perihelion of Mercury, an anomaly of Mercury’s orbit that didn’t square with Newton’s math, that vexed physicists for more than 200 years, and that was perfectly explained by Einstein’s eventual insights.
Ken Krimstein has published cartoons in The New Yorker, Punch, the Wall Street Journal, and more. He is the author of The Three Escapes of Hannah Arendt, which won the Bernard J. Brommel Award for Biography and Memoir, and was a finalist for the Jewish Book Award and the Chautauqua Prize, and also of Kvetch as Kvetch Can. He lives and writes and draws in Evanston, Illinois.
Geoscientists confirm 'dripping' of Earth's crust beneath Türkiye's Central Anatolian Plateau
Artist’s impression of two types of lithospheric drip: one produces thickening and uplift of Earth’s crust, while the other results in the formation of a basin at the surface without horizontal deformation. Credit: Julia Andersen / University of Toronto
Recent satellite data reveal that the Konya Basin in the Central Anatolian Plateau of Türkiye is continually being reshaped over millions of years, according to a new analysis led by Earth scientists at the University of Toronto.
The researchers say experimental simulations—combined with geological, geophysical and geodetic data—explain the enigmatic sinking of the basin within the rising plateau interior and further suggests a new class of plate tectonics that has implications for other planets that do not have Earth-like plates, such as Mars and Venus.
The study, published in Nature Communications, shows the sinking in the region is due to multi-stage lithospheric dripping—a phenomenon named for the instability of rocky material that makes up Earth's crust and upper mantle. As dense rock fragments beneath the surface detach and sink into the more fluid layer of the planet's mantle, major landforms such as basins and mountainous folding of the crust form at the surface.
"Looking at the satellite data, we observed a circular feature at the Konya Basin where the crust is subsiding or the basin is deepening," says lead author Julia Andersen, a Ph.D. candidate in U of T's department of Earth sciences in the Faculty of Arts & Science. "This prompted us to look at other geophysical data beneath the surface where we saw a seismic anomaly in the upper mantle and a thickened crust, telling us there is high-density material there and indicating a likely mantle lithospheric drip."
The results echo a similar investigation by the researchers into the formation of the Arizaro Basin in the Andes Mountains of South America, suggesting the phenomenon can occur anywhere on the planet, and explain tectonic processes typically found within mountain plateau regions.
Past studies show the Central Anatolian Plateau has risen by as much as one kilometer over the past 10 million years because of the lithospheric dripping phenomenon.
"As the lithosphere thickened and dripped below the region, it formed a basin at the surface that later sprang up when the weight below broke off and sank into the deeper depths of the mantle," says Russell Pysklywec, a professor in the department of Earth sciences and a co-author of the study.
"We now see the process is not a one-time tectonic event and that the initial drip seems to have spawned subsequent daughter events elsewhere in the region, resulting in the curious rapid subsidence of the Konya Basin within the continuously rising plateau of Türkiye."
Andersen adds that the new findings suggest a connection between plateau uplift and basin formation events through the evolution of primary and secondary lithospheric removal. "Essentially, subsidence is occurring alongside the ongoing uplifting of the plateau."
Andersen and study co-authors, including colleagues at Istanbul Technical University and Çanakkale Onsekiz Mart University in Türkiye, arrived at their findings after recreating the dripping process in laboratory experiments and analyzing their observations.
They built laboratory analog models to establish how the process may have unfolded based on the data provided by the new measurements, filling a plexiglass tank with polydimethylsiloxane (PDMS)—a silicone polymer fluid approximately 1,000 times thicker than table syrup—to serve as Earth's fluid lower mantle, adding a mixture of PDMS and modeling clay to replicate the upper-most solid section of the mantle, finishing with a sand-like layer on top made from ceramic and silica spheres to serve as Earth's crust.
The researchers activated the model by inserting a high-density seed into the PDMS and modeling clay layer to initiate a drip that was subsequently pulled downward by gravity. A set of cameras was positioned above and beside the tank to record any changes over time, capturing a high-resolution image roughly every minute.
"Within 10 hours, we observed an initial phase of dripping, which we call a primary drip. After that primary drip touched the bottom of the box, we saw a second drip had begun to sink to the bottom after 50 hours," says Andersen. "Both the primary and secondary drip were not causing any horizontal deformation in our artificial crust, which we expect is typically associated with a mantle lithospheric drip."
The researchers already knew that the primary drip had caused changes in surface topography of the experiment, and wanted to know if the secondary drip would have any effect on the surface since it was a smaller sized drip than the primary drip.
"What we noticed was that over time, this secondary drip did pull the crust downward and started to create a basin, despite no horizontal movements in the crust at the surface," Andersen says. "The findings show these major tectonic events are linked, with one lithospheric drip potentially triggering a host of further activity deep in the planetary interior."
More information: A. Julia Andersen et al, Multistage lithospheric drips control active basin formation within an uplifting orogenic plateau, Nature Communications (2024). DOI: 10.1038/s41467-024-52126-7
