Argentine ants will do anything for sugar, but they won’t do this

 An Argentine ant tending aphids, plant parasites that secrete a sugar-rich substance the ants consume.
 Photo Credit: UCLA/Noa Pinter-Wollman

It might seem like common sense that a starving animal is more likely to take dangerous risks to obtain food than one with a full belly. But new research from UCLA shows that groups of Argentine ants, who forage boldly when they’re well fed, exercise far more caution when they’ve been deprived of carbohydrates and the risks from competitors are high.

This counterintuitive foraging strategy might contribute to the success of these insects, known as Linepithema humile, an invasive species that displaces native ant populations in California and elsewhere and has become a significant agricultural pest, the researchers said.

Their findings, published in the journal Current Zoology, suggest that the unwillingness of Argentine ants to expose themselves to danger when weakened by hunger could possibly give them a competitive edge over other species by helping to preserve their colonies’ foraging capabilities.

“While not foraging may lead to a reduction in food stores when those stores are already low, foraging in a high-risk environment exposes the colony to potential loss of foragers,” said the study’s senior author, Noa Pinter-Wollman, a UCLA professor of ecology and evolutionary biology. “So reduced foraging could be interpreted as individual foragers not taking unnecessary risks.”

Researcher Aims to Uncover Plant Invasions in the Tropics

Invasive plants are invading all major ecosystems across Central America compromising the conservation of native species.
Photo Credit: Julissa Rojas-Sandoval

Invasive species of plants have a knack for settling in new settings and making big changes to an ecosystem, even leading to extinctions of native species.

Assistant Research Professor in UConn’s Institute of the Environment Julissa Rojas-Sandoval explains that invasive plants are non-native species that have been introduced into new areas generally as a result of human activities, and that they are actively spreading, causing harm to the environment, the economy, and human health. Invasive plants may have significant long-term implications for the conservation of native biodiversity, but to combat the problem, we need to know which plants are invasive, where they’re from, and how they got there.

Rojas-Sandoval leads an international collaboration including researchers from all Central American countries, working together to compile the most comprehensive databases of invasive plant species in Central America. The collaboration is called FINCA: Flora Introduced and Naturalized in Central America, and their first paper was published this week in Biological Invasions.

The collaboration arose to meet a need, says Rojas-Sandoval. “While we have a good understanding of the processes and mechanisms of plant invasions in temperate regions, there is a huge gap in our knowledge about biological invasions in the tropics, and this lack of information is limiting our ability to respond to invasive plants.”

The Superpowers of the Female Locust

Elongation of the body of the female locust while laying eggs in the ground
Illustration Credit: Tel Aviv University

Every mother will do anything to know that her offspring are in a safe place. The female locust, however, takes it to a whole new level: A new Tel Aviv University study has discovered that these females have superpowers. The female locust’s central nervous system has elastic properties, allowing her to stretch up to two or three times her original length when laying her eggs in the ground, without causing any irreparable damage.

“We are not aware of a similar ability in almost any living creature,” say the researchers. “Nerves in the human nervous system, for example, can stretch only up to 30% without tearing or being permanently damaged. In the future, these findings may contribute to new developments in the field of regenerative medicine, as a basis for nerve restoration and the development of synthetic tissues.”

“The superpower of the locust is almost something out of science fiction. There are only two other known examples in nature of a similar phenomenon: the tongue of the sperm whale, and a certain type of sea snail whose nervous systems are able to extend significantly due to an accordion-like mechanism they have." Prof. Amir Ayali

Environmental DNA uncovers a 2-million-year-old ecosystem in Greenland

Reconstruction of the Kap København formation two-million years ago, in a time where the temperature was significantly warmer than northernmost Greenland today.
Illustration Credit: Beth Zaiken.

Around 2 million years ago, climate in Greenland resembled the forecast of a future under global warming: with trees such as poplars and birch and animals like hare, lemmings, mastodons and reindeer.

Paleoclimatic records show strong polar amplification with annual temperatures of 11–19 degrees Celsius above current values. The biological communities inhabiting the Arctic during this time remain poorly known because animal fossils are rare.

An international team, including a researcher from Lawrence Livermore National Laboratory (LLNL), report the oldest ancient environmental DNA (eDNA) record to date, describing the rich plant and animal assemblages of the Kap København Formation in north Greenland that existed 2 million years ago. The research appears on the cover of the Dec. 7 issue of the journal Nature.

Ancient DNA has been used to map a two-million-year-old ecosystem, which weathered extreme climate change. Researchers hope the results could help to predict the long-term environmental toll of today’s global warming.

Mekong Delta will continue to be at risk for severe flooding

Mekong River Delta
Photo Credit: Tsuyoshi Watanabe

Reef corals provide an accurate, high-resolution record of the influence of the El Niño Southern Oscillation on rainfall, flooding and droughts in the Mekong River Delta, Vietnam.

The Mekong River Delta is the agricultural heartland of Vietnam; it is affected by droughts and flooding, which have become more severe in recent years. If severe weather events can be more accurately predicted, risk assessments in the regions can be improved. This, in turn, will reduce the negative effects of floods and droughts in the region.

A team led by Tsuyoshi Watanabe at Hokkaido University has revealed the clearest picture yet of how the El Niño Southern Oscillation (ENSO) affected rainfall in the Mekong Delta over the last hundred years. Their findings were published in the journal Scientific Reports. They correlated water salinity data from reef coral samples with historical weather records and uncovered that the ENSO has caused seasons of heavy and light rainfall, resulting in patterns of both flooding and droughts, respectively.

The ENSO occurs in the central and Eastern tropical Pacific Ocean, in irregular cycles of two to seven years. It consists of the El Niño (warming of the ocean surface), La Niña (cooling of the ocean surface) and neutral (neither warming, nor cooling).

Common medicine can stop the transmission of HIV infection from mother to child

The risk of transmission of HIV infection from mother to child has been reduced in resource-poor countries.
Photo Credit: Antony Trivet

Antiviral drugs almost completely reduce the risk of mothers passing on HIV infection to their children, even in a low-income country with a high HIV incidence such as Tanzania, according to a new study in The Lancet HIV by researchers from Karolinska Institutet. The discovery raises hopes of achieving the World Health Organization’s goal of eliminating the spread of infection from mother to child.

Only 159 infants were infected

The women were followed for 18 months after giving birth when most of them had stopped breastfeeding. When the researchers examined the mothers’ children, they discovered that only 159 of the more than 13,000 infants had been infected with HIV by the age of 1.5 years. Taking into account the margin of error, this means a risk of 1.4 per cent.

Wearable sensor could guide precision drug dosing

 The sensor uses microneedles that are made by cutting down clinical-grade acupuncture needles.
Image Credit: Emaminejad Lab/UCLA

For some of the powerful drugs used to fight infection and cancer, there’s only a small difference between a healing dose and a dose that’s large enough to cause dangerous side effects. But predicting that margin is a persistent challenge because different people react differently to medications — even to the same dose.

Currently, doctors can calibrate the amount of medication they administer in part by drawing blood to test the amount of medicine in a patient’s body. But results from those tests often take a day to process and only measure dosage at one or two moments in time, so they don’t help much when determining how to adjust dosage amounts in real time.

Now, a UCLA-led research team has developed a wearable patch that uses inexpensive microneedles to analyze the fluid between cells less than a millimeter underneath the skin and continuously record concentrations of medicine in the body. The technology could be a step toward improving doctors’ ability to administer precise medication doses.

In a study published in Science Advances, the investigators tested the system in rats that had been treated with antibiotics. Using data taken by the device within about 15 minutes after the medication was administered, the researchers reliably forecast how much of that drug would be effectively delivered to the animal’s system in total.

Brookhaven Lab to Lead New 'Saturated Glue' Theory Collaboration

Gluons at the Speed of Light
Gluons are always popping in and out of existence like blinking fireflies. But when nuclei or protons are accelerated to high energies, the gluons inside appear to multiply. That's because time operates in weird ways near the speed of light. The "blinking" appears to slow down, which makes the gluons linger longer. Energetic particle collisions can help physicists study this gluon-dominated state and, guided by new approaches to nuclear theory, search for signs of gluon saturation.
Illustration Credit: Brookhaven National Laboratory

The U.S. Department of Energy (DOE) has announced funding for a new Topical Theory Collaboration to be led by DOE’s Brookhaven National Laboratory that will aid in the discovery and exploration of a saturated state of gluons. These aptly named particles carry the nuclear strong force, acting as the ‘glue’ that holds together quarks, the building blocks of all visible matter. By understanding gluons’ ability to split and recombine and potentially reach a state of saturation, scientists hope to gain deeper insight into the strong force and the role gluons play in generating the mass, spin, and other properties of hadrons—composite particles made of quarks, such as the protons and neutrons of atomic nuclei.

The SatURated GluE (SURGE) Topical Theory Collaboration aims to develop calculations and a theoretical framework for discovering this unique saturated form of gluonic matter. Such a saturated state is predicted by the theory of quantum chromodynamics (QCD) to be observable in particles accelerated to high energies in particle colliders such as the Relativistic Heavy Ion Collider (RHIC) at Brookhaven Lab, the Large Hadron Collider (LHC) at Europe’s CERN laboratory, and the future Electron-Ion Collider (EIC) at Brookhaven.

Using light to manipulate neuron excitability

MIT and Harvard University researchers have devised a way to achieve long-term changes in neuron activity. With their new strategy, they can use light exposure to change the electrical capacitance of the neurons’ membranes, which alters their excitability (how strongly or weakly they respond to electrical signals).
Photo Credit: SFLORG stock image

Nearly 20 years ago, scientists developed ways to stimulate or silence neurons by shining light on them. This technique, known as optogenetics, allows researchers to discover the functions of specific neurons and how they communicate with other neurons to form circuits.

Building on that technique, MIT and Harvard University researchers have now devised a way to achieve longer-term changes in neuron activity. With their new strategy, they can use light exposure to change the electrical capacitance of the neurons’ membranes, which alters their excitability (how strongly or weakly they respond to electrical and physiological signals).

Changes in neuron excitability have been linked to many processes in the brain, including learning and aging, and have also been observed in some brain disorders, including Alzheimer’s disease.

“This new tool is designed to tune neuron excitability up and down in a light-controllable and long-term manner, which will enable scientists to directly establish the causality between the excitability of various neuron types and animal behaviors,” says Xiao Wang, the Thomas D. and Virginia Cabot Assistant Professor of Chemistry at MIT, and a member of the Broad Institute of MIT and Harvard. “Future application of our approach in disease models will tell whether fine-tuning neuron excitability could help reset abnormal brain circuits to normal.”

Jawbone may represent earliest presence of humans in Europe

For over a century, one of the earliest human fossils ever discovered in Spain has been long considered a Neandertal. However, new analysis from an international research team, including scientists at Binghamton University, State University of New York, dismantles this century-long interpretation, demonstrating that this fossil is not a Neandertal; rather, it may actually represent the earliest presence of Homo sapiens ever documented in Europe.

In 1887, a fossil mandible was discovered during quarrying activities in the town of Banyoles, Spain, and has been studied by different researchers over the past century. The Banyoles fossil likely dates to between approximately 45,000-65,000 years ago, at a time when Europe was occupied by Neandertals, and most researchers have generally linked it to this species.

“The mandible has been studied throughout the past century and was long considered to be a Neandertal based on its age and location, and the fact that it lacks one of the diagnostic features of Homo sapiens: a chin,” said Binghamton University graduate student Brian Keeling.

The new study relied on virtual techniques, including CT scanning of the original fossil. This was used to virtually reconstruct missing parts of the fossil, and then to generate a 3D model to be analyzed on the computer.