Getting to the “bottom” of how beetles use their butts to stay hydrated
Beetles are known for being able to survive in extremely dry environments and can even go their entire lives without drinking any liquid water at all. This is in part due to the fact that they’re able to suck water from the air using their… rear ends.
Now, a new study in PNAS has gotten to the bottom of exactly how they manage it, revealing the molecular mechanisms that allow beetles to absorb water rectally.
The team studied the internal organs of red flour beetles (Tribolium castaneum) and identified a gene (Nha1) that is expressed 60 times more in the beetle’s rectum compared to the rest of the animal. The gene encodes for a protein that transports salts in a unique group of cells known as leptophragmata cells.
“Leptophragmata cells are tiny cells situated like windows between the beetle’s kidneys and the insect circulatory system, or blood,” says Kenneth Veland Halberg, Associate Professor in the Department of Biology at the University of Copenhagen in Denmark, who led the research.
“As the beetle’s kidneys encircle its hindgut, the leptophragmata cells function by pumping salts into the kidneys.”
This produces the osmotic gradient necessary for water to be removed from the faeces and into the body.
“Insects are particularly sensitive to changes in their water balance,” says [Halberg?] “As such, this knowledge can be used to develop more targeted methods to combat beetle species which destroy our food production, without killing other animals or harming humans and nature.”
Smart bandage monitors wounds and treats them at the same time
Researchers at the California Institute of Technology have designed a new kind of smart bandage that senses symptoms of inflammation and infection and simultaneously administers treatment.
“There are many different types of chronic wounds, especially in diabetic ulcers and burns that last a long time and cause huge issues for the patient. There is a demand for technology that can facilitate recovery,” says Wei Gao, Assistant Professor of medical engineering at Caltech in the US, and senior author of the study.
Made from a flexible and stretchy polymer, the bandage is embedded with medication and a sensor that monitors for molecules like uric acid or lactate, and conditions like pH level and temperature in the wound.
It can transmit the gathered data wirelessly for review by the patient or medical professional, can deliver an antibiotic directly to the wound site, and even apply a low-level electric field to stimulate tissue growth and promote faster healing.
This research was conducted in animal models, so next steps will involve testing it on human patients.
“We have showed this proof of concept in small animal models, but down the road we would like to increase the stability of the device, but also to test it on larger chronic wounds because the wound parameters and microenvironment may vary from site to site,” says Gao.
Keeping valuables, and potentially people, safe in bushfire-safe rooms
Australian engineers have built and tested a bushfire-safe room that exceeds current Australian standards, whichcould protect valuables or even people when evacuation is no longer possible.
“Building materials used in bushfire flame zones only have a standard recommendation of 30 min standard fire exposure,” says Dr Anthony Ariyanayagam from the Queensland University of Technology’s Faculty of Engineering, who led the research.
“But, unlike a structural fire, bushfire temperatures can reach 1100°C in a very short time and building performance can be highly affected by this sudden increase.”
The bushfire-safe room is built with cavity insulated light gauge steel framed walls, and the roof is lined externally with Autoclaved Aerated Concrete panels and internally with fire-rated gypsum plasterboard.
During testing, the external wall temperature reached a maximum of 958°C at 30 mins during peak flame exposure, while internal surfaces remained under 29 °C with a less than 1 °C rise in internal air temperature.
“The bushfire-safe room demonstrated excellent bushfire heat resistance and is a viable solution for storage of valuables,” says Ariyanayagam.
The current standard for private bushfire shelters says that an able-bodied person should be able to stay in one for about an hour to withstand the fire front.
“In theory, people could survive in this shelter for up to two hours, but we need to test other conditions like air quality before recommending human survivability too,” he adds.
The research has been published in the journal Structures.
Robot caterpillar demonstrates a new way for soft robots to move
Caterpillars have inspired the design of a new soft robot that can move forward, backward, and squeeze under narrow spaces by curving its body using a pattern of embedded silver nanowire heaters.
“Engineering soft robots that can move in two different directions is a significant challenge in soft robotics,” says Yong Zhu, Distinguished Professor of Mechanical and Aerospace Engineering at North Carolina State University in the US.
“A caterpillar’s movement is controlled by local curvature of its body – its body curves differently when it pulls itself forward than it does when it pushes itself backward,” says Zhu, who is corresponding author of a new paper describing the work in Science Advances.
The caterpillar-bot is made from two layers of polymer that each respond differently when exposed to heat; the top layer expands and the bottom layer contracts.
“We can control which sections of the robot bend by controlling the pattern of heating in the soft robot. And we can control the extent to which those sections bend by controlling the amount of heat being applied,” says Zhu.
Although the robot moved faster the more current that was applied, the researchers found there was an optimal cycle of heating which gave the polymer enough time to cool before contracting again, so as to not impair its movement.