Putting Tried-and-True Theories to the Test

Assistant Professor of Physics Katerina Chatziioannou
Source: California Institute of Technology

Albert Einstein's general theory of relativity is a triumph of science, celebrated by scientists around the world for, among other truths, explaining how gravity works. Whereas Isaac Newton proposed in the late 17th century that gravity is a force tugging on objects, Einstein taught us, in the early 20th century, that gravity is in fact a warping of space and time. The more massive an object, the more it curves space and produces stronger gravity.

Now, many decades later, scientists are using a prediction of Einstein's general theory of relativity—gravitational waves—to study the universe and to even poke holes in the theory itself. Einstein predicted these ripples in spacetime 100 years ago but they were not directly detected until 2015, when the National Science Foundation-funded LIGO (Laser Interferometer Gravitational-wave Observatory) detected the waves from a collision between two black holes.

Assistant Professor of Physics Katerina Chatziioannou, who joined the Caltech faculty in 2020 and is part of the LIGO team, is using gravitational waves to explore these extreme events. She is using the waves to study the space-bending objects themselves, such as black holes and neutron stars, as well as to look for places where our current knowledge of gravity might break down. Any deviations from the tried-and-true theory could lead to new discoveries in physics.

Stroke cuts life expectancy by one third

Almost two thirds of acute stroke patients fail to survive more than a decade and have high risk of recurrence, prompting researchers to call for better patient care.

University of Queensland researchers analyzed data from more than 300,000 patients admitted to hospital following a sudden stroke between 2008 and 2017 in Australia and New Zealand.

The team also investigated how many years were lost to stroke by comparing a patient’s predicted life expectancy with the length of actual survival.

Study leader and UQ epidemiologist, Dr Yang Peng, a Research Fellow with the Prince Charles Hospital Northside Clinical Unit, said only 36.4 per cent of patients survived beyond 10 years, and 26.8 per cent had another stroke.

“We found that a stroke reduced a patient’s life expectancy by five and a half years on average, compared with the general population,” Dr Peng said.

“In proportional terms, this meant a stroke reduced a person’s life expectancy by one third.

“Patients with a hemorrhagic stroke who have bleeding in the brain are at greater risk of death, another stroke and reduced life expectancy, than those with an ischemic stroke, which is caused by a burst blood vessel.”

Acute stroke is one of the most common causes of hospitalization and disability in Australia and has been linked to risk factors such as high blood pressure, elevated cholesterol levels, diabetes, smoking and heart disease by the Stroke Foundation.

Nationwide maps of bird species can help protect biodiversity

Researchers mapped the number of bird species found across the contiguous U.S. Blue areas host fewer bird species than green or yellow areas do. 
Images by Kathleen Carroll and Anna Pidgeon

New, highly detailed and rigorous maps of bird biodiversity could help protect rare or threatened species.

Researchers at the University of Wisconsin–Madison developed the maps at a fine-enough resolution to help conservation managers focus their efforts where they are most likely to help birds — in individual counties or forests, rather than across whole states or regions.

The maps span the contiguous U.S. and predict the diversity of birds that live in a given area, related by traits such as nesting on the ground or being endangered. Those predictions are based on both detailed observations of birds and environmental factors that affect bird ranges, such as the degree of forest cover or temperature in an area.

Changes in vegetation shaped global temperatures over last 10,000 years

Alexander Thompson, a postdoctoral research associate in earth and planetary sciences in Arts & Sciences, updated simulations from an important climate model to reflect the role of changing vegetation as a key driver of global temperatures over the last 10,000 years.
Source: Washington University in St. Louis

Follow the pollen. Records from past plant life tell the real story of global temperatures, according to research from a climate scientist at Washington University in St. Louis.

Warmer temperatures brought plants — and then came even warmer temperatures, according to new model simulations published in Science Advances.

Thompson had long been troubled by a problem with models of Earth’s atmospheric temperatures since the last ice age. Too many of these simulations showed temperatures warming consistently over time.

But climate proxy records tell a different story. Many of those sources indicate a marked peak in global temperatures that occurred between 6,000 and 9,000 years ago.

Thompson had a hunch that the models could be overlooking the role of changes in vegetation in favor of impacts from atmospheric carbon dioxide concentrations or ice cover.

Scientists resurrect ancient enzymes to improve photosynthesis

 Maureen Hanson, the Liberty Hyde Bailey Professor of Plant Molecular Biology in the College of Agriculture and Life Sciences, and Myat Lin, research associate, work in their lab in the Biotechnology Building.
Credit: Ryan Young/Cornell University

A Cornell study describes a breakthrough in the quest to improve photosynthesis in certain crops, a step toward adapting plants to rapid climate changes and increasing yields to feed a projected 9 billion people by 2050.

The study, “Improving the Efficiency of Rubisco by Resurrecting Its Ancestors in the Family Solanaceae,” published in Science Advances. The senior author is Maureen Hanson, the Liberty Hyde Bailey Professor of Plant Molecular Biology in the College of Agriculture and Life Sciences. First author Myat Lin is a postdoctoral research associate in Hanson’s lab.

The authors developed a computational technique to predict favorable gene sequences that make Rubisco, a key plant enzyme for photosynthesis. The technique allowed the scientists to identify promising candidate enzymes that could be engineered into modern crops and, ultimately, make photosynthesis more efficient and increase crop yields.

Their method relied on evolutionary history, where the researchers predicted Rubisco genes from 20-30 million years ago, when Earth’s carbon dioxide (CO2) levels were higher than they are today and the Rubisco enzymes in plants were adapted to those levels.

Researcher identifies peptide active against certain cancers

Shugeng Cao in his lab.
Credit: University of Hawaiʻi

A University of Hawaiʻi researcher has identified a rare bacterium that is active against certain cancers. The bacterium, Lentzea flaviverrucosa, that produces petrichorin A, was discovered by Shugeng Cao, associate member of the Cancer Biology Program at the UH Cancer Center, and co-investigators Chunshun Li and Xiaohua Wu, in collaboration with Joshua Blodgett of Washington University in St. Louis. The research team proved that petrichorin A is active against cancers such as ovarian cancer, fibrosarcoma, prostate cancer and T-cell leukemia.

These findings were published in the Proceedings of the National Academy of Sciences of the United States of America.

Petrichorin A is a peptide that contains special amino acids, and each amino acid has a nitrogen-nitrogen bond. Petrichorin A, a dumbbell-like natural product, was evaluated for anti-cancer activity against multiple cancer cell lines. The researchers conducted a preliminary test and discovered that petrichorin A was not toxic to a normal human cell line. With this observation, his team proved that petrichorin A was active against ovarian cancer, fibrosarcoma, prostate cancer and T-cell leukemia. This highlighted the importance of including petrichorin A in future research of pharmaceutical design and discovery programs.

Cloud server leasing can leave sensitive data up for grabs

Renting space and IP addresses on a public server has become standard business practice, but according to a team of Penn State computer scientists, current industry practices can lead to "cloud squatting," which can create a security risk, endangering sensitive customer and organization data intended to remain private.

Cloud squatting occurs when a company, such as a bank, leases space and IP addresses — unique addresses that identify individual computers or computer networks — on a public server, uses them, and then releases the space and addresses back to the public server company, a standard pattern seen every day. The public server company, such as Amazon, Google, or Microsoft, then assigns the same addresses to a second company.  If this second company is a bad actor, it can receive information coming into the address intended for the original company — for example, when you as a customer unknowingly use an outdated link when interacting with your bank — and use it to its advantage — cloud squatting.

"There are two advantages to leasing server space," said Eric Pauley, doctoral candidate in computer science and engineering. "One is a cost advantage, saving on equipment and management. The other is scalability. Leasing server space offers an unlimited pool of computing resources so, as workload changes, companies can quickly adapt." As a result, the use of clouds has grown exponentially, meaning almost every website a user visits takes advantage of cloud computing.

A right to clean drinking water?

Dr. Edith Nettmann is a microbiologist at the Chair for Urban Water Management and Environmental Technology.
Credit: Damian Gorczany

Water is the elixir of life on our planet. The free availability of clean water must not be a privilege. Therefore, in 2010 the United Nations decided that everyone has the right to clean water and sanitation. However, this human right has not yet been implemented globally. Around 2.2 billion people still have no access to drinking water and around 4.4 billion no sanitary facilities are available. Given these numbers, it is difficult not to speak of a crime against humanity.

People in emerging and developing countries and / or in rural regions are particularly affected. There are many reasons for this: among other things, a lack of / missing wastewater treatment and corresponding infrastructures, environmental pollution, still a lack of information about hygiene, armed conflicts and climate change.

Many fatalities

Worldwide, over 80 percent of all wastewater is still fed into the water cycle untreated. They not only pollute the environment and drinking water resources, but also contribute to the spread of diseases in addition to poor hygiene. These include cholera, typhoid, dysentery and hepatitis A. Children in particular are worst hit: in the past ten years, more children worldwide have died of water-related diarrhea than people in all armed conflicts since the Second World War. Today, 450 million children already live in areas with high or extremely high-water uncertainty. And climate change is exacerbating this precarious situation. The increasing extreme weather conditions caused by global warming, such as droughts, floods and heavy rain events, have a very strong influence on the amount and quality of our drinking water.

Quantum teleportation: the express lane for quantum data traffic

An artist’s conception of an error-correction protocol: the photons affected by environment are fixed then used to carry the data teleported into them.
Credit: Maria Slussarenko

Teleportation may be a concept usually reserved for science fiction, but researchers have demonstrated that it can be used to avoid loss in communication channels on the quantum level.

The team, including researchers from Griffith University’s Centre for Quantum Dynamics, has highlighted the issues around inherent loss that occurs across every form of communication channel (for example, internet or phone) and discovered a mechanism that can reduce that loss.

Dr Sergei Slussarenko
from the Centre of Quantum Dynamics.

Professor Geoff Pryde, Dr Sergei Slussarenko, Dr Sacha Kocsis and Dr Morgan Weston, and researchers from The University of Queensland and the National Institute of Standards and Technology, say the finding is an important step towards implementing ‘quantum internet’, which will bring unprecedented capabilities not accessible with today’s web.

Dr Slussarenko said the study was the first to demonstrate an error reduction method that improved the performance of a channel.

“First, we looked at the raw data transmitted via our channel and could see a better signal with our method, than without it,” he said.

“In our experiment, we first sent a photon through the loss – this photon is not carrying any useful information so losing it was not a big problem.

Decoy particles trick coronavirus as it evolves

Decoy nanoparticle explainer
Credit: Northwestern University

Emerging therapeutics could overcome drug-resistant variants

They might look like cells and act like cells. But a new potential COVID-19 treatment is actually a cleverly disguised trickster, which attracts viruses and binds them, rendering them inactive.

As the ever-evolving SARS-CoV-2 virus begins to evade once promising treatments, such as monoclonal antibody therapies, researchers have become more interested in these “decoy” nanoparticles. Mimicking regular cells, decoy nanoparticles soak up viruses like a sponge, inhibiting them from infecting the rest of the body.

In a new study, Northwestern University synthetic biologists set out to elucidate the design rules needed to make decoy nanoparticles effective and resistant to viral escape. After designing and testing various iterations, the researchers identified a broad set of decoys — all manufacturable using different methods — that were incredibly effective against the original virus as well as mutant variants.

In fact, decoy nanoparticles were up to 50 times more effective at inhibiting naturally occurring viral mutants, compared to traditional, protein-based inhibitor drugs. When tested against a viral mutant designed to resist such treatments, decoy nanoparticles were up to 1,500 times more effective at inhibiting infection.