Killer whales are mama’s boys
New research has found that the killer whale (orcinus orca) mothers are caring for their children into adulthood, and this affects their ability to have more babies.
“The magnitude of the cost that females take on caring for their weaned offspring was really surprising,” says Michael Weiss, a researcher at the University of Exeter in the UK and the Center for Whale Research in the US.
“While there is some uncertainty, our best estimate is that each surviving offspring reduces a female’s chances of having a new offspring in a given year by more than 50%. This is a huge cost to take care of (adult) children!”
The researchers studied a pod of orcas known as the “Southern Resident” population in coastal waters off Washington state and British Columbia in the US, which has been monitored since 1976 by the Center for Whale Research.
Whales have a bizarre social system where males and females stay with their mothers for life. By analyzing existing data, the team was able to determine that there is a strong negative correlation between the number of surviving weaned offspring of females and their annual probability of producing a viable calf.
These findings suggest that there are significant benefits for female killer whales as well, keeping their adult offspring alive and well.
“Females gain evolutionary benefits when their offspring are able to successfully reproduce, and our results indicate that these benefits are sufficient to offset a large direct cost,” explains Weiss.
The southern resident population of killer whales is critically endangered, and a major concern is their low reproductive rates, so these findings could have important conservation implications, helping to inform future population viability analyses.
The new study is in current biology.
A solar-powered hydrogel that filters clean water
A potential solution to meet the global need for reliable access to clean water works a lot like a sponge – soaking up clean water while leaving contaminants behind.
Engineers detail the next generation of sun-absorbing gel technology in a new study in the journal ACS Central Science. The spongy gel only needs sunlight to filter out pollutants, including heavy metals, oils, microplastics and some bacteria.
This new iteration has nearly four times the filtering rate compared to the first generation technology developed in 2021; a square meter of material one centimeter thick can produce over 3.5 liters of water in just 1 minute.
The hydrogel is formed from a polymer called poly(N-isopropylacrylamide), or PNIPAm, which can absorb or release water depending on the temperature. Below 33°C, the hydrogel absorbs water from a source, but when removed and heated by sunlight to temperatures above 33°, it begins to release water.
Under the midday sun, the gel can release about 70% of the water it absorbs in just ten minutes.
Other polymers added to its surface in this iteration include polydopamine (PDA), which filters contaminants from the water, and poly(sulfobetaine methacrylate) or PSBMA, which binds tightly with water molecules on the gel surface to form a hydration layer that repels oil and bacteria – allowing the device to be self-cleaning.
“There have been many efforts to develop technology that uses solar energy to create clean, drinkable drinking water, but often they fail to produce enough water to meet daily needs,” says Rodney Priestley, Professor of Chemical and Biological Engineering at the University of California. Princeton, in the US.
“This latest iteration of our technology brings us one step closer towards our goal of having a solar-powered technology that can actually produce enough clean water to meet daily demand.”
Move over bone marrow, you’re not the only one making blood cells
Scientists investigating the causes of lymphedema have made a major discovery – lymph vessels can produce both red and white blood cells. The new Nature the study changes our understanding of how blood cells are produced; Until now, it was believed that blood cells were derived only from bone marrow stem cells.
Lymph vessels return excess tissue fluid and protein (lymph) back into the bloodstream and are an important component of the immune system, transporting white blood cells.
Lymphedema occurs when lymph vessels within the lymphatic system become blocked or damaged, causing swelling in the body’s soft tissues (most often in the arm or leg). It is a long-term condition that cannot be cured, only managed.
“We discovered a site in the DNA that is important for the control of genes that program the identity and development of lymphatic vessels”, explains the principal investigator, Professor Natasha Harvey, a developmental biologist at the University of South Australia and director of the Center for Cancer Biology in Australia .
“If these genes aren’t turned on at the right time and place, the lymph vessels don’t form properly, causing lymph fluid to back up into the tissues, leading to swelling (lymphedema),” she says.
“In an unexpected discovery, we identified that the same gene that controls the development of lymph vessels also controls the production of blood cells.”
“This exciting discovery suggests that lymphatic vessels may be a previously unrecognized source of blood cells during development and disease.”
The finding raises questions about whether this ability might be important for fighting infections or might play a role in some types of blood cancers.
The researchers will now investigate what causes lymph vessels to produce different types of blood cells and when this occurs – during normal development and in disease.
First evidence of mass stellar migration to the Andromeda Galaxy
Galaxies, like the Milky Way, grow and evolve over billions of years, forming new stars and merging with other galaxies through “galactic immigration” events.
Until now, it has only been possible to study these immigration events in our own galaxy. But a new study in Astrophysical Journal discovered evidence of a major galactic immigration event in the Andromeda Galaxy – the Milky Way’s closest large galactic neighbor.
The team studied the motions of around 7,5000 individual stars in the inner halo of the Andromeda Galaxy, also known as Messier 31 (M31), and found patterns in the positions and motions of the stars that revealed that they began their lives as part of another galaxy. which merged with M31 about 2 billion years ago.
“Our new observations of the Milky Way’s closest large galactic neighbor, the Andromeda Galaxy, reveal evidence of a galactic immigration event in exquisite detail,” says Arjun Dey, NOIRLab astronomer at the National Science Foundation (NSF) in the US, and main author of the paper.
“While the night sky appears unchanging, the Universe is a dynamic place. Galaxies like M31 and our own Milky Way are built from the building blocks of many smaller galaxies throughout cosmic history.”
The discovery was made possible by the Dark Energy Spectroscopic Instrument (DESI) – the most powerful multi-object survey spectrograph in the world.
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