You are here

Science News

Wednesday, 20 December, 2017 - 15:40

Researchers at Punjab University have developed a sensor pattern noise based method to detect forged videos where one video is copied onto a different video.

The digital age has been slowly spreading with increasing surveillance and other autonomous systems replacing the old manually operated ones. CCTV cameras, head/ vehicle mounted cameras and devices like Go-pro enable live recording of events as they unfold. The videos generated have already had a huge impact on law enforcement, providing clues and evidence to solving a case. They have also assisted other professions like journalism, politics and even military and intelligence operations. However, the main concern with video based evidence is their accuracy. Increasingly, fake videos and morphed pictures have been used for political gains or to mislead a jury. Assisted by the social media platforms where videos can go viral, having huge reach, such forged videos can have a huge impact and as such it has become crucial to detect any changes and forgeries made to video, before making them public.

One of the preferred methods for forgery is through the copy-paste method, wherein the content of a video is altered by copying content from a different video. In their study, the researchers have improved the conventional method of video forensics. They also studied a demosaicing artifact based image forensic scheme, to check the validity of the technique in video forensics.

Next, the researchers set up a neutral testing platform with a set of tampered MJPEG, MPEG-2, MPEG-4 and H.264/AVC videos with varying strength of post-production re-compressions, bitrates, and size of tampered regions to present a real-world scenario. The novel sensor pattern noise based copy-paste detection is an improvement of the current noise-residue based technique, with an average detection accuracy of around 89%-98%, compared to the 64% to 82% of the conventional methods.

“Amidst the continual march of technology, we find ourselves relying on digital videos to proffer visual evidence in several highly sensitive areas. Therefore, in a situation where dependence on video evidence is unavoidable, it becomes crucial to authenticate the contents of this evidence before accepting them as an accurate depiction of reality” remark the researchers, and their study could provide a way to ensure the accuracy of the output.

Section: General, Science, Technology Source: Link
Tuesday, 19 December, 2017 - 16:02

Scientists from Indian Institute of Technology Madras, Chennai and Indian Institute of Science, Bengaluru have developed a novel complex made of silk fibroin (SF) with embedded silver oxide nanoparticles (Ag2O) for wound healing and anti-bacterial applications.

Silk has been used by humans for around 8500 years now for different uses. Apart from making expensive clothes, it has also found use as an improvised material for many medical applications including wound healing and reconstructive surgery, mainly due to its organic make-up and physical properties, like tensile strength. With the advent of nanotechnology, this ancient material has undergone several additions to make it an ideal material for many medical and industrial applications. The new study explores one such addition to silk to make it an anti bacterial material capable of healing wounds.

To prepare the silver oxide nanoparticles embedded silk fibroin spun, the scientists used microwaves to help the nanocrystals grow on the silk fibroin, a protein found in silk. Once the presence of silver oxide nanocrystals was confirmed using UV-Vis spectrometric analysis, where the spectrum produced by the material is examined with UV and visible light. The scientists also used a Scanning electron microscope and Differential scanning calorimetry to confirm the structure of the silver oxide embedded silk fibroin. Next an X-ray diffraction revealed the crystalline nature of the both the materials; the silk fibroins and silver oxide nanocrystals.

Once the composition of the composite material was confirmed, it was inserted into phosphate buffered saline (PBS) to study its biodegradation properties, where it showed insignificant changes even after 14 days. The combination of Ag2O and SF also showed excellent anti-bacterial activities, promptly acting against pathogens, like M. tuberculosis, and non-pathogens, like E-Coli. In vitro studies of its wound healing properties also revealed quick reactions from the material enabling fast migration of T3T fibroblast cells. “Cytotoxicity assay confirmed the biocompatible nature of the Ag2O-SF spuns, thus suggesting an ideal material for wound healing and anti-bacterial applications.” Exclaim the researchers.

Section: General, Science, Technology, Health Source: Link
Monday, 18 December, 2017 - 15:49

Scientists from Indian Institute of Science (IISc.), Bengaluru develop a new technique to trap micro particles using the surface features of glass which could help scientist study collective phenomenon and properties of colloidal particles.

Suspending micro particles of polystyrene and silicon dioxide has been the long-standing method to study the behaviour of colloidal particles. Trapping such particles allows scientists to probe properties like self-assembly of colloidal particles to form crystals, and many other condensed matter phenomenon. Conventional techniques employ optical holographic tweezers which use high-energy lasers to trap the particles. However, optical trapping techniques have their own drawbacks, with the main shortcoming being the throughput of such a technique. The low throughput affects studies like flocking and jamming, which requires many particles being trapped together. The technique is also limited by the laser intensity that the sample material can withstand

The scientists from IISc used triangular crest shaped structures on a glass substrate to help pin down the particles. The new method uses a combination hydrodynamic forces and adhesion to pin the particles of polystyrene to the substrate. First, the particles are added in an aqueous solution. As the density of polystyrene exceeds that of water, the particles sink to the bottom. Next, the particles are pumped through microfluidic channels carved into the glass substrate and allowed to settle, which helps the particles to stick to the substrate. However, if the particles are pumped continuously or if the particles are smaller than five micrometers in size, they don’t adhere to the substrate and instead just flow across it. The new method allows for a high throughput of pinned particles in any desired two dimensional patterns, while sacrificing the dynamic trapping pattern that is achievable using an optical trapping method.

“This method allows trapping and pinning of microspheres in any arbitrary pattern with a high degree of spatial accuracy which can be useful in studying fundamentals of various collective phenomena as well as in applications such as bead detachment assay based biosensors” claim the scientists talking about the importance of the research.

Section: General, Science, Technology Source: Link
Friday, 15 December, 2017 - 13:47

Scientists from Indian Institute of Science (IISc) have developed a novel device made of a fibre Bragg grating to measure the force exerted with a bite.

The maximum voluntary bite force is the force exerted on an object placed between the two rows of teeth, while biting into it. The force is a result of three components; muscle of mastication-- the muscles which help the jaws move, the jaw, and teeth, together called the craniomandibular structure. The measure of force is considered as a good indicator of the state of the masticatory system- which allows animals to chew and crush the food.

To measure the force, the scientists made use of the fiber Bragg grating (FBG), a device which acts as an optical filter allowing certain wavelengths of lights to pass through, while blocking others. Sensors made of the FBG can be used to measure the differences in force, by measuring the different wavelengths of light emanating from an area where the force is applied.

The novel Bite Force Measurement Device (BMFD) consists of a non-invasive intraoral devices, which when bit into, can transfer the bite force into strain variations on a metal plate. This shows up as dents and valleys on the metals plate. Next, the FBG bonded to the metal plate reads the strain variations and provides a value for the force applied, much like studying the aftermath of an earthquake to study how powerful the quake was. The BMFD device also allows for an adjustable biting platform, which ensures the platform captures three essential positions of the teeth; incisor, pre-molar and molar sites. The three values together can provide an accurate picture of the health of the masticatory system and the bite force one exerts.

With the new device, the researchers went onto the measure the force exerted at each of the teeth positions- incision, premolar and molar, and compared them to each other. They have also compared the force differences in the bite force exerted by the different genders. The scientists believe “measurement of voluntary bite force provides useful data for the jaw muscle function and activity along with assessment of prosthetics”. 

Section: General, Science, Technology Source: Link
Thursday, 14 December, 2017 - 15:24

Researchers from Pondicherry University, Puducherry and SRM University, Chennai have recently demonstrated a novel device made of Nickel/ Nickel oxide (Ni/NiO) and graphene that could be used to store hybrid-energy.

The rising use of alternative and renewable energy sources also increases the need to store enormous amounts of energy. Unlike fossil fuels, which can be burnt when there is a need for the energy, renewable sources, like solar and wind, is only available intermittently. Using these sources efficiently requires devices like batteries and supercapacitors to store the energy when it is generated. However, battery technology, unlike other technologies, has not seen huge advancements.

In the new study, the scientists studied the properties of Ni/NiO anchored on graphene oxide. Using a mixture of nickel nitrate and citric acid at a mixture ratio of 1:1, nanoparticles of Ni/NiO were formed. These nanoparticles demonstrated high specific capacity (around 158C/g)- a measure of how well an object can charge and discharge. Next, the Ni/NiO nanoparticles were anchored on to a substrate made of reduced graphene oxide (rGO) using a method called probe sonication, where sound waves are used to agitate the nanoparticles and help them stick to the rGO surface. With the nanoparticles attached to the graphene surface, the specific capacity of the apparatus shot up to 335 C/g to almost twice as before. The new device Ni/NiO @rGO, also showed improved cycling stability, high rate capability and Coulombic efficiency, properties which allows it to charge and discharge efficiently, with minimal loss and high stability.

The researchers constructed a rudimentary supercapacitor or energy storing device with the Ni/NiO @rGO as the positive electrode, rGO as the negative electrode and a thin layer of dried gel made of polyvinyl alcohol (PVA), separating the two, acts as the electrolyte, and. The set up was then used to light up LEDs to demonstrate its storage and discharge capabilities, with the device storing higher amounts of energy than conventional devices. The study opens new avenues into hybrid energy storage devices that allows for a new generation of efficient batteries that can power the next generation of our gadgets.

Section: General, Science, Technology Source: Link
Wednesday, 13 December, 2017 - 16:10

Scientists from the Indian Institute of Technology- Madras, Chennai and CSIR- Central Leather Research Institute, Adyar, Chennai have developed a new drug combination to effectively treat diabetic wounds.

Polyglutamic acid, a type of polymer made of amino acid and glutamic acid, which aids in the biosynthesis of proteins, has been known to help with healing wounds. However, the healing properties of L-Glutamic acid (LG), another type of glutamic acid widely occurring in nature, have not been studied yet. LG is also known to be a precursor to collagen synthesis which is a major component of fibrous tissue, tendons, ligaments and skin.

In their new study, the scientists combined LG along with Chitosan (CS) hydrogels, a major component of chitin cells found in shrimps and other crustaceans. The combination of LG and CS was found to remain stable under varying temperatures, and also showed smooth surface morphology and controlled biodegradation. Compared to chitosan alone or natural healing of the wounds, the combination of CS and LG showed a rapid wound contraction. The combination drug also showed significant reduction in the time taken for epithelialisation, where tissue forms to protect a wound from the environment. While epithelialisation takes around 26 days naturally and around 20 days with chitosan alone, it took only around 16 days LG+CS hydrogels.

Diabetic rats treated with a combination of LG+CS hydrogels showed an improved collagen synthesis and crosslinking. A dressing of the wounds using the combination drug also revealed and increase in vascularisation- process by which new blood vessels are formed, while also increasing the recruitment of macrophages- a type of white blood cell that protects from infections.

The scientists believe “these results demonstrate that incorporation of LG aid in faster tissue regeneration. Therefore, CS + LG hydrogels could be an effective wound dressing used to treat diabetic wounds.” 

Section: General, Science, Health Source: Link
Tuesday, 12 December, 2017 - 15:43

Scientists from Sun Yat-sen University, China, International Centre for Genetic Engineering and Biotechnology, Delhi, Indian Institute of Rice Research and Agri Biotech Foundation have explored the microbiome or microbes associated with a major rice pest, Asian Rice Gall Midge.

The Asian Rice Gall Midge is an insect about the size of a mosquito and a member of the specialized gall making insect family Cecidomyiidae. It spends most part of its life cycle within the rice plant. Upon hatching, the larva of the midge which is known as the maggot, slides down between leaf sheaths. After reaching the apical meristem, which is the part of the plant at the extremities from where vertical growth occurs, the maggot begins feeding by lacerating the plant tissue. The maggot induces changes in the plant such that a gall can be formed around its body, which contains nutritive nurse cells that can sustain it for the next phases of its life. The successful establishment of the insect in the plant means that the plant cannot bear grains.

Previous studies had explored the plant’s defence mechanisms against the midge, but studies have not explored the role of the insect’s microbiome in its interaction with the plant. An insight into the plant-midge-microbe interactions could provide us with novel strategies to control this infection.

For their latest study the scientists used next generation sequencing (NGS) protocol to identify different bacterial species associated with the midges and the plant.

The microbiome of the Asian Rice Gall Midge was made up of both rare and abundant species. Wolbachia species and Psuedomonas species of bacteria were commonly found in the Asian Rice Gall Midge. Wolbachia sp has been described as a microbe with a capacity to change several traits of its host, while Psuedomonas sp. are also known to be present in other pest species. Most notably, the study shows that the bacterial community structure differed among different host plant and different stages of development of the midge. These variation observed in the microbiome of the Asian Rice Gall Midge with reference to the host from which they were isolated indicate that they might have an influential impact on the midge and plant interaction.

Section: General, Science, Ecology, Health Source: Link
Monday, 11 December, 2017 - 13:59

An international team of scientists from Indian Institute of Technology –Indore, India, University of Witwatersrand,  South Africa, Raman Research Institute, India, Tata Institute of Fundamental Research, India and Australia Telescope National Facility, Australia has, for the first time, calculated the power radiated by high-energy electrons in radio galaxies and galaxy clusters.

Galaxy clusters are the most massive, gravitationally bound structures, that form when multiple galaxies, under the force of gravity, come together to form a cluster of galaxies. Radio galaxies are galaxies that radiate high amounts radio frequency and appear very bright under a radio telescope. When high energy electrons or electrons moving close to speed of light, called relativistic electrons, diffuse in the magnetic fields of a galaxy clusters or radio galaxies, it emits huge amounts of radio waves through a process of non-thermal radiation emission, also called synchrotron- where the characteristics of the radiation does not depend on the temperature of the emitting particle. The amount of power radiated by this process however, still remains a mystery, as the lower limit of the electron energy distribution or the low-energy cut-offs of the electron energy is still not fully understood. The lower limit of electron energy in turn depends on the lower limit of the momentum of the electron, using which the total power output could be calculated.

For their study, the scientist used a phenomenon called Sunyaev-Zel’dovich Effect to measure the lower limit of the momentum of the electron. When high-energy relativistic electrons strike the photons of the cosmic microwave background (CMB)- the halo of light persistent throughout the universe formed as a result of the big bang, the electron can distort the photons, making the electron lose energy and photons gain energy. By studying the amount of energy gained by the photons of the CMB, the scientists could determine the lower limit of the electron momentum.

The team studied the Sunyaev-Zel’dovich Effect in a far away bullet cluster, and have been able to propose a lower limit for the momentum of the electrons, thus giving them an idea of the power radiated by such electrons in galaxy cluster and radio galaxies. The study could give us a better picture of cosmic phenomenon like galaxy cluster merger and formation of large-scale structures in the Universe.

Section: General, Science Source: Link
Friday, 8 December, 2017 - 16:41

Researchers from the CSIR- Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh have discovered the presence of a novel cryptic virus tentatively called the Arhar cryptic virus-1 in Pigeonpea plants from pigeonpea field in Telangana state.

It is unclear in biology whether viruses can be considered as living beings. Viruses are a complex assembly of molecules consisting of an outer protein envelope within which the genetic material is housed. These complex materials can only replicate inside the body of a host, using the molecular machinery of the host to aid their replication. As the study of virology evolved, cryptic viruses were discovered.

Cryptic viruses evaded detection by scientists as they cause little or no symptoms in the infected plant. They contain double stranded RNA as genetic material and are not transmitted from infected to healthy cells as other viruses usually do. Plant crypto viruses are usually transmitted through pollen or seeds.

In their recent study, scientists reported for the first time an infection of the pigeonpea plant by a cryptic virus. Tentatively named Arhar cryptic virus-1, this discovery is important as pigeonpea is one of the major grain legume crops of the Indian subcontinent.

Four double stranded stand RNA segments were isolated from pigeonpea plants. Using a method called Sequence Independent Single Primer Amplification, the different genomic segments of the double stranded RNAs were characterized. Three out of the four isolated RNA formed the genome of the newly identified cryptic virus, while the fourth RNA resembled the protein coat of an unrelated virus.

Along with the characterisation of the entire genomic sequence of the cryptic virus, the researchers conducted a structural analysis of the RNA dependent RNA polymerase, an important enzyme required in the replication of the virus. Through the structural analysis of the enzyme and comparing it with other RNA dependent RNA polymerases the team were able to display that the sequence for this enzyme was conserved in cryptic viruses and which part of the sequence performed what function in replication.

From the information gathered through this study, the researchers hope that future biochemical and X-ray crystallography experiments will help us better understand RNA dependent RNA polymerases and their relevance in RNA synthesis.

Section: General, Science, Health Source: Link
Friday, 8 December, 2017 - 08:33

Scientists from Indian Institute of Technology- Dhanbad have been looking at the available technological options to turn waste to energy for an effective source of waste management and energy production.

Although technological advancements have advanced battery technologies and alternative energy sources, fossil fuels continue to be the preferred source of power for most countries globally. Traditional fuels like kerosene, natural gas, biomass, continue to be the primary source for 25% of households globally. However, a global movement against fossil fuels due to the threat they pose to the environment, has seen the rise of new alternative energy sources. One such option is the conversion of municipal waste into energy (WTE). The process converts solid waste into energy by either burning or by collecting the gases produced at landfill sites.

In their study, the scientists review the technological options for WTE, globally. Incineration or burning, pyrolisis (decomposing organic waste using high temperatures), gasification (converting organic material into carbon and hydrogen), anaerobic digestion (decomposing in the absence of oxygen) and land-filling with gas recovery, are some of the common methods used. While incineration was found to be the most widely used method in developed countries, land-filling was found to be the most common method for dealing with municipal solid waste in developing countries. Around 50 million tonnes of methane is produced at a landfilling site, which can then be collected and used. Unsanitary landfilling was also found to be common in many developing countries.

Conversion of waste into energy could not only provide the a part of the energy needs of a community, but can also help with dealing with the enormous amounts of organic and inorganic waste coming out of a city in a developed and developing countries. The scientists believe “this review will help the policy makers and the implementing authorities involved in MSWM to understand the current status, challenges and barriers for effective management of municipal solid waste”

Section: General, Science, Society Source: Link