Study finds much still not known about cognitive decline

Why do some elderly people keep their cognitive ability much longer than others? Scientists still have much to learn.
Photo Credit: Alexandra Lowenthal

The risk factors linked to cognitive decline in older adults explain a surprisingly modest amount about the large variation in mental abilities between older people, according to a new national study.

Researchers found that the factors most commonly associated with cognitive functioning – including socioeconomic status, education and race – explained only 38% of the variation in functioning among Americans at age 54.

Health behaviors such as avoiding obesity and smoking and participating in vigorous exercise had only very small effects on functioning by the time people reached their mid-50s.

In addition, the factors studied explained only 5.6% of the variation in how quickly cognitive functioning declined in people between age 54 and 85.

Protein droplets may cause many types of genetic disease

Close-ups of cell nuclei in a human cell culture: HMGB1 protein (green) is usually found throughout the nucleus (dotted line). Mutant HMGB1, shown on the right, preferentially localizes at the nucleolus (marked in magenta) and forms a solidified layer over it, which causes disease.
Image Credit: MPIMG/ Henri Niskanen

Malfunction of cellular condensates is a disease mechanism relevant for congenital malformations, common diseases, and cancer

Most proteins localize to distinct protein-rich droplets in cells, also known as “cellular condensates”. Such proteins contain sequence features that function as address labels, telling the protein which condensate to move into. When the labels get screwed up, proteins may end up in the wrong condensate. According to an international team of researchers from clinical medicine and basic biology, this could be the cause of many unresolved diseases.

Patients with BPTA syndrome have characteristically malformed limbs featuring short fingers and additional toes, missing tibia bones in their legs and reduced brain size. As the researchers found out, BPTAS is caused by a special genetic change that causes an essential protein to migrate to the nucleolus, a large proteinaceous droplet in the cell nucleus. As a result, the function of the nucleolar condensate is inhibited and developmental disease develops.

Scientists discover toughest known material at ultra-cold temperatures

Microstructure and fractography of the CrCoNi-based alloys
Image Credit: Dr Dong Liu

Researchers at the University of Bristol have discovered an alloy that shows increased strength at over -250°C, making it the toughest material on record.

The findings, published in Science, show that chromium-cobalt-nickel alloy displays a high fracture toughness in cryogenic temperatures paving the way for its use in extreme environments on Earth and in space.

The behavior of this particular combination of metals is caused by a phase transformation that, when combined with other nano-scale mechanisms, prevents crack formation and propagation.

Lead author Dr Dong Liu of Bristol’s School of Physics, explained: “This is very interesting because most alloys become more brittle with a decrease in temperature. I reference the sinking of liberty ships in WWII and Titanic which were due to the metals losing its ductility at low temperatures.”

“People often mix the concept of strength and toughness. If you Google, ‘what is the toughest materials on earth?’ ‘Diamond’ will jump out on the top line. Diamond is the hardest known material to date, but hardness is usually related to strength of a material - diamond is indeed very hard and strong but it is not tough.”

Mapping How Singlet Oxygen Molecules Travel Along DNA Strands

A recent study has unveiled with unprecedented detail how singlet oxygen molecules diffuse along double strand DNAs, paving the way to more effective nucleic acid-targeting photodynamic therapy (PDT). A research team at Tokyo Tech used a novel photosensitizer and custom-made DNA sequences to shed light on the optimal position to anchor the photosensitizer to achieve the best oxidizing effect. This could help make this type of PDT more lethal to cancer cells.

Nucleic acid-targeting photodynamic therapy (PDT) is a promising type of targeted therapy that is being actively researched. This treatment relies on special photosensitizers, a type of drug that binds at specific locations in a cell's DNA. Once bound, the cells are irradiated at a precise frequency, which in turn causes the photosensitizer to produce reactive oxygen species (ROS) or singlet oxygen (1O2) molecules. These molecules tend to oxidize nearby nucleic acids, damaging the genetic material and ultimately killing the irradiated cell.

Although the overall process may sound straightforward, there are still many hurdles to overcome before this type of PDT is good enough for clinical practice. One of them is that even though type II oxidation (the one caused by 1O2) has certain advantages over type I oxidation (the one caused by ROS), there is very little information on how far 1O2 molecules can reach once generated. Because of this knowledge gap, it is difficult to decide which location in the DNA should be targeted to achieve the best effect.

New immunotherapy can be effective for ovarian cancer

Patients with ovarian cancer usually have a poor prognosis.
Photo Credit: National Cancer Institute

A certain type of immunotherapy in which the body's T cells are programmed to attack cancer cells, called CAR-T cell therapy, is effective in ovarian cancer mice. It shows a study published in The Journal for Immuno Therapy of Cancer by researchers from Karolinska Institutet who hope the findings pave the way for a clinical trial to see how effective the treatment is for women with the disease.

This treatment exists today for patients with blood cancer and we now want to investigate whether we can use the method to treat ovarian cancer. Despite many improvements in treatment, women with ovarian cancer have continued to have a poor prognosis, says Isabelle Magalhaes, associate professor at Department of Oncology-Pathology at Karolinska Institutet and shared the last author of the study. 

St. Jude scientists create more efficient CAR immunotherapies using a molecular anchor

Senior author Stephen Gottschalk, M.D., (left) and corresponding author Peter Chockley, Ph.D., (right) both of the St. Jude Department of Bone Marrow Transplantation and Cellular Therapy.
Photo Credit: Courtesy of St. Jude Children's Research Hospital

Scientists at St. Jude Children’s Research Hospital added a molecular anchor to chimeric antigen receptors (CARs), increasing the anti-cancer activity of cellular immunotherapies in cancer models.

Adding a molecular anchor to the key protein that recognizes cancer in cellular immunotherapies can make treatments significantly more effective. Scientists at St. Jude Children’s Research Hospital found that immune cells with the anchored protein increased cancer killing, regardless of the cancer’s cell type or the form of cancer targeted. The molecular anchor concept is a new design for improving chimeric antigen receptor (CAR)-based-immunotherapies. CARs have shown some promise in the clinic but have yet to deliver widespread success across tumor types. The findings were published in Nature Biotechnology.

Menindee Lakes water savings project: study shows poor government consultation and decision-making

The Darling River flows from north to south, with water overflowing into the Menindee Lakes, including Lake Menindee (top right) and Lake Cawndilla (top middle), both forming important wetlands within Kinchega National Park.
Photo Credit: Richard Kingsford

A controversial project in the Murray-Darling Basin was ‘misguided and poorly framed’, UNSW scientists say.

A study led by researchers at the Centre for Ecosystem Science at UNSW Sydney has examined a large water-savings project at Menindee Lakes in News South Wales.

The Menindee Lakes are part of the Murray-Darling Basin – the largest basin in Australia, spanning one-seventh of the continent. 2.2 million people live across its area, and its surface water supplies about 40 per cent of Australia’s irrigated agricultural output.

“The Menindee Lakes project is among the key mechanisms devised by governments to deliver on the Murray-Darling Basin Plan – a major inter-government initiative to provide water for rivers and wetlands in the basin,” said UNSW Professor Richard Kingsford, Director of the Centre for Ecosystem Science and co-author of the study.

The $151.8 million project’s goal is to save water for the Basin Plan by implementing infrastructure measures and rule changes to reduce water lost to evaporation from Menindee Lakes.

Researchers develop elastic material that is impervious to gases and liquids

This image shows a container made of the new material that is elastic, flexible, and impervious to both gases and liquids. The material can be used to make ‘soft’ batteries for use with wearable electronics and other devices.
Photo Credit: Michael Dickey.

An international team of researchers has developed a technique that uses liquid metal to create an elastic material that is impervious to both gases and liquids. Applications for the material include use as packaging for high-value technologies that require protection from gases, such as flexible batteries.

“This is an important step because there has long been a trade-off between elasticity and being impervious to gases,” says Michael Dickey, co-corresponding author of a paper on the work and the Camille & Henry Dreyfus Professor of Chemical and Biomolecular Engineering at North Carolina State University.

“Basically, things that were good at keeping gases out tended to be hard and stiff. And things that offered elasticity allowed gases to seep through. We’ve come up with something that offers the desired elasticity while keeping gases out.”

A new understanding of reptile coloration

A small sample of variations in coloring seen in captive-bred ball pythons (Python regius).
Image Credit: McGill University

Snakes and mice don’t look alike. But much of what we know about skin coloration and patterning in vertebrates generally, including in snakes, is based on lab mice. However, there are limits to what mice can tell us about other vertebrates because they don’t share all of the same types of color-producing cells, known as chromatophores. For example, snakes have a type of chromatophore called iridophores that can generate iridescent colors by reflecting light.

To gain a better understanding of the genetic basis of coloration in vertebrates, a McGill University-led research team combined a range of techniques (whole gene sequencing, gene-editing, and electron microscopy) to look more closely at color variations and patterning in the skin shed by ball pythons bred in captivity. They were able to identify a particular gene (tfec) that plays a crucial role in reptile pigmentation generally and more specifically in a classic color variant found across vertebrates and distinguished by blotches of white, the piebald.

Breakthrough laboratory confirmation of key theory behind the formation of planets, stars and supermassive black holes

Pillars of Creation: By combining images of the iconic Pillars of Creation from two cameras aboard NASA’s James Webb Space Telescope, the universe has been framed in its glory. The pillars are the vast clouds of dust and gas in the foreground that swirl around and form celestial bodies. 
Hi-Res Zoomable Image
Photo Credit: JWST/NASA

The first laboratory realization of the longstanding but never-before confirmed theory of the puzzling formation of planets, stars and supermassive black holes by swirling surrounding matter has been produced at the Princeton Plasma Physics Laboratory (PPPL). This breakthrough confirmation caps more than 20 years of experiments at PPPL, which is based at Princeton University.

The puzzle arises because matter orbiting around a central object does not simply fall into it, due to what is called the conservation of angular momentum that keeps planets and the rings of Saturn from tumbling from their orbits. That’s because the outward centrifugal force balances out the inward pull of gravity on the orbiting matter. However, the clouds of dust and plasma called accretion disks that swirl around and collapse into celestial bodies do so in defiance of the conservation of angular momentum.    

The solution to this puzzle, a theory known as the Standard Magnetorotational Instability (SMRI), was first proposed in 1991 by University of Virginia theorists Steven Balbus and John Hawley. They built on the fact that in a fluid that conducts electricity, whether the fluid be plasma or liquid metal, magnetic fields behave like springs connecting different sections of the fluid. This allows ubiquitous Alfvén waves, named after Nobel Prize winner Hannes Alfvén, to create a turbulent back-and-forth force between the inertia of the swirling fluid and the springiness of the magnetic field, causing angular momentum to be transferred between different sections of the disk.