Sentinel Wrap: A new patch to detect food spoilage

• Do you double check the expiry date before buying food items? You may soon be able to check the state of your food using your smartphone. Scientists from McMaster University in Canada have developed a transparent patch that can generate a fluorescence signal when bacteria like E.coli and Salmonella start to form on a food item.
• The patch can be kept in the packet by the manufacturer and the signal can be read by the consumer using special attachments to the cell phone.

Rock and roll gives Earth its nitrogen

• Where does Earth get its nitrogen from? It was long believed that nitrogen gas was naturally available in the atmosphere. But now scientists have shown that about 26 % of the nitrogen in natural ecosystems comes from weathering of rocks.
• The mountain ranges of Himalayas and Andes were found to be important sources of the gas.
• They analysed ancient rock samples and found that they hold large amounts of the gas.
• They also examined Earth’s nitrogen balance, other geochemical processes and built a nitrogen weathering model for the whole planet.

Mutant bacteria are not so bad

• Researchers from California Institute of Technology have engineered E.coli in such a way that it has started producing a difficult-to-make group of chemicals – bicyclobutanes. They genetically modified the bacteria by giving it an extra gene that encodes for a particular enzyme, which in turn led to the production of these chemicals. Bicyclobutanes have a complex structure making it extremely difficult and highly energy consuming to produce in a lab. These chemicals have wide range of applications in pharmaceutical and agrochemical industries.

WBC home test kit

• Patients undergoing chemotherapy treatment are more prone to life-threatening infections as their WBC (white blood cells, the defence cells of our body) count drops after every radiation session.
• Now researchers from MIT have developed a prototype kit that records the flow of blood cells through capillaries under the skin at the base of your fingernail.
• The video is then analysed by a computer algorithm which determine if WBC count is within the threshold. This new device can help patients monitor their WBC count at home without the need of a blood test.

Sleep-wake cycle linked to weight gain

• Early to bed and early to rise makes a man healthy, wealthy and wise. Scientists from Stanford University have now proved the first part of the saying right by studying circadian (biological clock) hormones.
• They found that hormones that stimulate the production of fat cells changed their patterns when the sleep-wake cycle was altered. The levels of the hormone glucocorticoid rise during the day and gradually decrease at night.
• The researchers found that stress and disturbance in the sleep cycle altered this pattern, which in turn led to weight gain.

New underwater GPS

• Now you can navigate underwater using the same technique used by shrimps – follow polarisation patterns. Light transmission from air to water and in-water scattering forms polarisation patterns which can be used as a compass for geolocalization.
• Researchers from University of Queensland, Australia have developed a new polarization-sensitive imager, which points out the geolocation of the observer based on radial underwater polarization patterns.
• This device may soon help submarines in long-distance underwater navigation.

Source:TH