You may have missed… edible food defrosting sensor, social spider hunting and new ovarian cancer test

A self-powered, edible, food defrosting sensor

Italian researchers have developed the first self-powered, and edible, defrosting sensor, which could one day be used to detect improper freezing of food.

It’s composed of a galvanic cell with an aqueous electrolyte solution that generates an electrical current, but only at temperatures above the freezing point of the solution (when the product is defrosting).

Then, a colour changing system indicator, based on red cabbage juice, produces an irreversible shift from reddish purple to blue when the galvanic cell produces electrical current – providing information about defrosting events.

The two parts are bound together by a block of beeswax and the temperature at which the sensor reacts can be tuned between 0 and −50 °C by changing the salts present, or their concentration, in the electrolyte solution.

The new device has been described in a study published in ACS Sensors, and the authors suggest that “as a sensor, it could be used by the workers in the supply chain, while as a detector, it could be useful for end consumers, ensuring that the food was properly frozen during the whole supply chain.”

Holding sensor 850
This first self-powered, and edible, defrosting sensor, could one day be used to detect improper freezing of food. Credit: IIT-Istituto Italiano di Tecnologia

A simple new test for ovarian cancer

A global study into rare mucinous ovarian cancer could help oncologists recommend the best treatment for women who are diagnosed with the condition early.

Using a microscope to examine the tissue of 604 patients, scientists looked for two different “patterns of invasion” – the way that cancer cells invade ovarian tissue.

They found that the infiltrative pattern of invasion, in which cancer cells spread in an uneven, haphazard way through ovarian tissue, was associated with poorer health outcomes. Whereas the other expansile pattern of invasion, where cancer cells expand through ovarian tissue in a more orderly manner, was associated with better prognoses.

Read more: Endometriosis may be linked to ovarian cancer – but it’s not all bad news.

This suggests that oncologists can better predict which patients may have better or worse prognoses and can target treatment accordingly.

“Knowing this in the early stage of the disease means we can identify patients who could benefit from additional chemotherapy following surgery to remove their ovaries,” explains lead author Dr Nicki Meagher, who completed her PhD in the Molecular Oncology group in the University of New South Wales School of Clinical Medicine.

The research has been published in the journal Clinical Cancer Research.

New virus discovered at La Trobe University officially named Latrobevirus

In 2019, researchers from La Trobe University in Australia discovered a virus that attacks the disease-causing Fusobacterium. This bacterium recruits other harmful bacteria into a biofilm to cause periodontitis – severe gum infection – and potentially helps certain cancers grow and spread.

Latrobe virus
Transmission Electron Micrograph image of Latrobevirus with long ≈310 nanometer tail and icosahedral head diameter of ≈88 nm. Credit: Kabwe et al 2019, Scientific Reports, DOI: 10.1038/s41598-019-45549-6

This bacteriophage virus has now been officially recognised by the International Committee on Taxonomy of Viruses (ICTV), who have named it the Latrobevirus in recognition of its totally new taxonomic genus, or group.

“Prescribing antibiotics to kill an unwanted bacterium is like trying to kill an ant with a shotgun,” says lead researcher Joseph Tucci, associate professor in Clinical Pharmacy at La Trobe.

“You damage a lot in the process – whereas if you can introduce a bacteriophage that targets only one particular kind of bacteria, you can kill those bacteria with precision therapy without harming the rest of your microbiome.”

Social spiders have different ways of hunting in groups

Spiders are normally solitary animals, but a few species have evolved to be social – living in colonies where they share communal nests and childcare duties.

Now, findings from a new study in the Journal of Arachnology suggests that environmental conditions may have shaped how species developed different strategies of cooperating when hunting.

Researchers explored the different responses to prey stuck in the webs among three social species of velvet spiders – African social velvet spider (Stegodyphus mimosarum), Indian cooperative spider (Stegodyphus sarasinorum), and African Social Spider (Stegodyphus dumicola).

They investigated the number of spiders which engaged in attacking prey, the time it took for the first spiders to attack, and the size of the prey (using grasshoppers, locusts, and crickets), and found substantial differences between them.

Indian cooperative spider
Indian cooperative spider (Stegodyphus sarasinorum). Credit: Virginia Settepani

The African social velvet spider and African Social Spider live in the same locations and show cautious and choosy group hunting approaches, while the Indian cooperative spider has a more opportunistic approach.

“This indicates that where two different social species share the same habitat, they have evolved their own niches in response to competition between them,” says lead author, Dr Lena Grinsted, a senior lecturer in Zoology at the University of Portsmouth, in the UK.

And if you are interested in the fascinating lifestyle of spiders you might like to know about the giant tarantula which befriends tiny frogs.

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