The application of modulated UV-C light to guavas—emitted in pulses or cycles rather than continuously—combated anthracnose. This fungal disease is caused by microorganisms belonging to the Colletotrichum gloeosporioides complex and triggers dark lesions on the fruit after harvest, reducing its shelf life. An article on the technique was published in the journal Horticulturae.

The disease usually manifests on the skin but can reach the pulp through injuries caused by insects, improper handling, or mechanical damage during transport. These factors, combined with inefficient post-harvest practices, contribute to an estimated 20% to 40% loss of total guava production in developing countries.

In this type of food, pathogen control has predominantly been carried out through the use of synthetic chemical pesticides, particularly fungicides. This involves immersing or spraying the fruit in a fungicide solution immediately after harvest, followed by drying and refrigerated storage.

“The chemicals used in post-harvest treatment end up causing chemical contamination, which is very harmful to human health, especially children, and to the environment. So, in this study … our goal was not only to provide an effective method of controlling this disease post-harvest, but also to develop a clean and sustainable technology that would leave no residue and preserve the integrity of the food,” says Daniel Terao, an agronomist and researcher at the Brazilian Agricultural Research Corporation (EMBRAPA) who participated in the study.

The new treatment developed by EMBRAPA consists of a cylindrical device with a mirror and three internal UV-C germicidal lamps. One lamp emits rays of light perpendicular to the surface of the structure, creating a cylinder of light. The second lamp is strategically positioned toward the mirror to reflect on the guava. The third lamp faces the fruit directly.

This mechanism ensures the food is illuminated by the maximum amount of radiation, which is absorbed on the surface and converted into heat. This inactivates microorganisms.

“This allows for more precise control of the product’s interaction with the light and reduces light energy losses, controlling the fungus that causes the disease and minimizing damage to the food’s epidermis. In this way, natural resistance mechanisms are enhanced, which means that the fruit itself is activated against the attack of microorganisms, preserving the quality of the food and increasing its shelf life,” Terao explains.

According to the researcher, the results of the study were very promising for treating guavas and other fruits, but they only occurred in a laboratory environment.

The next step is to validate the technology under real conditions at the producer’s facility and adapt the modulated UV-C light application equipment to the fruit processing line. This will allow the technique to be applied in practice.

New research confirms the potential for police forensic investigators to carefully consider the presence of pets at crime scenes as a credible new avenue for finding and investigating DNA leads to solve the case. The Long-running research by Flinders University and Victoria Police experts demonstrates how dogs and cats can be tested for indirect DNA transfer at crime scenes from people other than householders or pet owners.

Heidi Monkman, Ph.D. student from Flinders University’s College of Science and Engineering, with Dr. Roland van Oorschot from the Victoria Police Forensic Services Department and Luke Volgin from the Forensic Science South Australia, are breaking new ground with their research on animal-mediated human DNA transfer. Their recent studies reveal that household pets may play a surprising role in solving crimes.

“Dogs and cats are present in the majority of households worldwide and they routinely interact with multiple people and environments. Our findings show that dogs and cats can act as intermediaries in human DNA transfer, which has significant implications for casework where animals are present,” says Dr. Monkman, a co-author of several forensic DNA science articles on the topic.

The research discovered that even short contact between pets and people of interest, including potential offenders, leave detectable traces of human DNA on pets. It also found cats and dogs carry and spread human DNA as they move around a home or to other locations, transferring it from one surface to another.

“Awareness and use of this phenomenon could offer investigators important clues when piecing together evidence in serious criminal cases,” says Monkman.

The studies involved controlled interactions between dogs, cats and volunteers in order to monitor DNA transfer in various scenarios. They found that owners’ DNA present on their pets can be picked up by mock offenders, potentially linking them to crime scenes. The DNA also can be transferred to locations that the owners never touched, possibly linking them to crime scenes where they were not present.

In the most recent article, “Investigation of human DNA transfer during mock dog-napping,” published in Forensic Science International, researchers examined human DNA transfer dynamics in a mock “dog-napping” scenario.

Five dogs were placed into five separate cars by a recruited handler. The vehicles were neither owned by the handler nor familiar to the animals or their owners. The dogs remained in a car for 20 minutes and then returned home, where sampling took place one hour later.

Flinders University Senior Lecturer in Forensic Science Dr. Mariya Goray—a co-author of the journal articles—says while pets have often been overlooked in forensic casework, this research highlights their potential critical role in the dynamics of DNA transfer.

“These findings highlight the need for forensic investigators to carefully consider the presence of pets at crime scenes both as a possible new avenue for investigative leads, but also as a possible mechanism for indirect transfer and contamination,” says Dr. Goray.

In another journal article, “The role of cats in human DNA transfer” in Forensic Science International: Genetics, 20 different cats were tested; quantifiable DNA was detected in 16 or 80% of the samples taken.

The third paper, titled “Paws for a moment: Investigation of bi-directional transfer of human DNA during a short human-dog interaction and subsequent indirect transfer,” is published in Science & Justice.

“While little is known about collecting and analyzing human DNA to and from cats, we are exploring the potential for cats and dogs to be silent witnesses, to act as vectors of contamination and transfer at residential crime scenes,” says Monkman. “We know about 60% of households currently have a pet, and up to 90% a pet at some stage. They are the most common pet in most countries around the world.”

Constructed with tubulin heterodimers connected into a hollow cylinder, the microtubule, an essential component of the cytoskeleton, plays a vital role in various intracellular processes. In a recent study, a cross-disciplinary research team led by Professor Yuan Lin from the Department of Mechanical Engineering in the Faculty of Engineering, and Professor Jeff Ti from the School of Biomedical Sciences in the Li Ka Shing Faculty of Medicine at the University of Hong Kong (HKU), has revealed how the biological function of microtubules is achieved through mechanical regulation at the tubulin level.

Microtubules are hollow, cylindrical filamentous polymers of tubulins that function as force-bearing scaffolds or cargo-transport tracks in cells. To execute their biological functions, microtubules need to interact with groups of proteins—some binding to the microtubule’s exterior and others to its lumen. While the microtubule exterior is readily accessible to proteins, how luminal binding proteins gain access to the confined inner surface of microtubules remains a mystery. Specifically, the molecular mechanism by which the microtubule lattice determines the luminal accessibility has been elusive.

Combining single-molecule fluorescence microscopy-based assays with direct mechanical characterization by force microscopy, Professor Ti’s team, for the first time, revealed that tubulin isotypes (i.e., different variants of the tubulin protein) serve as the force-sensing element that regulates the accessibility of microtubule lumen for enzymes to interact with the substrates on the inner surface of the lattice. The research findings have been published in Nature Physics, titled “Tubulin isotypes of C. elegans harness the mechanosensitivity of the lattice for microtubule luminal accessibility.”

To elucidate the mechanistic insight into the roles of tubulin isotypes in regulating luminal accessibility, Professor Lin’s team developed a 3D computational model of the microtubule. Simulations revealed that the relatively weak lateral interaction of specific tubulin isotypes enables the reversible formation of inter-filament gaps when compressed. Experimentally validated, these transient gaps are large enough to allow entry of luminal binding proteins.

Together, these findings reveal a fundamental mechanism by which tubulin isotypes influence the strength of inter-protofilament lateral interactions, thereby governing luminal accessibility through reversible protofilament separation (i.e., lattice breathing). This demonstrates that the mechano-plasticity of microtubules can be regulated by their constituent tubulin isotypes, enabling distinct responses to thermally- or stress-induced mechanical deformation.

“In addition to significantly advancing our understanding of the phenomenon of mechano-transduction of cells, findings from this study could also provide critical insights for the development of novel active biomaterials in the future,” said Professor Lin and Professor Ti.