Reconstructed WW II Code Cracker Colossus Defeated

first_img Citation: Reconstructed WW II Code Cracker Colossus Defeated (2007, November 16) retrieved 18 August 2019 from A monumental achievment in reconstructing Colossus the first code cracker computer used by Allied forces in World War II. In a timed contest between Colossus and the modern PC Colossus was defeated by a modern program and a 1.4 GHz PC. A fourteen year project to reconstruct the World War II Allied forces Colossus the first code cracking computer ended in a match defeat against a modern 1.4 Ghz PC. The cipher event was instigated by The British National Museum of Computing and Cryptography at Betchley Park home of the newly reconstructed Colossus Mark II. The event challenged all interested parties to compete with Colossus in the deciphering of three enciphered messages. The German participants sent the messages utilizing the Lorenz SZ42 teleprinter using the same radio protocols as the German high command used in World War II.The original Colossus is regarded by many to have been instrumental in shortening the war in Europe by as much as 18 months. The Colossus about the size of a British small lorry was capable of deciphering messages sent by Hitler to his generals. The Nazi based Lorenz SZ40/42 machine enciphered messages that were sent by radio to the German high command. The only reason the messages were capable of deciphering was that the Lorenz SZ40 encryption was not entirely random.The process to unscramble the messages were painstaking and involved several layers of deciphering tasks. First the captured messages sent via the radio were punched on to paper tape. The paper tape was fed into Colossus at the rate of 5,000 characters per second. The inputted data became part of the memory of Colossus. Colossus then analyzed the data to determine the wheels of the Lorenz might have been set up to encipher the message. Various functions of the Colossus were used to perform this statistical analysis. The end result with a little luck thrown in would be a printed tape with the exact wheel of the Lorenz so the message could be deciphered. Generally it took about six hours to decipher a message. After World War II the six known Colossus computers were broken up and destroyed for a variety of reasons. Some 14 years ago Tony Sales and the founders of the aspiring British National Museum of Computing and Cryptography embarked on the project to reconstruct a Colossus using photos and scant information about the original machine. The winner of the cipher event Bonn, Germany resident Joachim Schuth used a program he wrote in ADA programming language to decipher the coded messages. The very noisy transmission was received by Schuth yesterday and his 1.4 Ghz PC took only 46 seconds to decipher the message using his program. The total time involved was two hours from the time when the message was first received to the end when it was actually deciphered. Unfortunately the radio transmission was troublesome due to atmospheric conditions. The Colossus got off to a rough start by getting the message late yesterday and beginning the process of deciphering early this morning when it was announced by Heise a German news service that Mr. Schuth had all ready cracked the code. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Colossus & Reconstructor Tony Sales: BBC – How Colossus Works EU fine on Google weighs on parent Alphabet profits Explore furtherlast_img read more

Researchers develop disposable paperbased touch pads

first_imgA paper-based touch pad on an alarmed cardboard box detects the change in capacitance associated with the touch of a finger to one of its buttons. The keypad requires the appropriate sequence of touches to disarm the system. Image credit: Mazzeo, et al. New multi-touch screen technology developed (w/ Video) ( — Today, electronic touch pads are widely found on laptops, tablets, and other computing devices. Less common uses, but gaining in popularity, are book covers and food labels. These and other low-tech applications become possible as touch pads become extremely inexpensive, with applications ranging from beer bottle labels to disposable medical device labels. Now a team of researchers from the US and France have developed paper-based electronic touch pads that cost just 25 cents per square meter, a price at which touch pads can simply be thrown away when no longer needed. More information: Aaron Mazzeo, et al. “Paper-Based, Capacitive Touch Pads.” DOI: 10.1002/adma.201200137via: Chemistry World Explore further The touch pads are made of metallized paper, which is paper coated in aluminum and transparent polymer. The paper can function as a capacitor, and a laser can be used to cut several individual capacitors in the paper, each corresponding to a key on the touch pad. When a person touches a key, the key’s capacitance is increased. Once the keys are linked to external circuitry and a power source, the system can detect when a key is touched by detecting the increased capacitance.According to lead researcher Aaron Mazzeo of Harvard University, the next steps will be finding a power source and electronics that are cheap, flexible, and disposable. Among the applications, inexpensive touch pads could be used for security purposes. The researchers have already developed a box with an alarm and keypad that requires a code to allow authorized access. Disposable touch pads could also be useful in sterile or contaminated medical environments. © 2012 Phys.Org Citation: Researchers develop disposable paper-based touch pads (2012, May 10) retrieved 18 August 2019 from This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

Researchers identify sterility genes in hybrid rice

first_imgThey identified three genes that contribute to the sterility in a “killer-protector” system that determines whether or not spores are formed. They found that Open Reading Frame (ORF) 5+ (killer) produces a protein that ORF 4+ influences to cause endoplasmic reticulum (ER) stress in the spore-producing cells, while a third gene, ORF 3+ (protector), produces a protein in response to the stress that counteracts it and protects the ER. The japonica variety has a different form of the gene, ORF 3-, which means that the hybrids often carry a muted ORF gene that is unable to protect against the hybrid’s more potent form of the killer ORF 5+, often resulting in premature death at the embryo-sac stage in the hybrid.The researchers explained in their paper in Science that a potent combination of ORF 4+ and ORF 5+ would allow genetic differentiation of the two subspecies and prevent genes being passed on, while a potent ORF 3+ and weaker combinations of the killer genes would allow hybrids to be fertile and genes to flow to the next generation.The findings add to the understanding of hybrid sterility, a process that restricts the flow of genes between populations, lead author Qifa Zhang said. He added that understanding the cause of the sterility may allow scientists to overcome it, and this could help in the development of more desirable and higher-yielding cultivated rice crops. Journal information: Science This image shows heterosis and sterility of hybrid between indica and japonica subspecies in rice. Credit: Jiangyi Yang and Qifa Zhang (—Hybrids of many plant and animal species and subspecies are sterile, and a group of researchers in China have now identified the genes that operate to make crossbred rice sterile. This image shows heterosis and sterility of hybrid between indica and japonica subspecies. Credit: Qifa Zhang The scientists, from the National Centre of Plant Gene Research at Huazhong Agricultural University in Wuhan and the Chinese University of Hong Kong, examined two subspecies of the cultivated rice (Oryza sativa L.), japonica and indica, and identified three genes that act together to regulate fertility in these hybrids. Japonica is a common variety of sticky short-grain rice also known as Japanese rice, sinica or sushi rice, and indica is a non-sticky long-grain rice. Both varieties are thought to have been first domesticated in Central China around eight thousand years ago, and from there they spread throughout Asia. When crossbred the hybrids tend to be more vigorous than the parent subspecies and can yield significantly larger crops of rice.The researchers used techniques such as gene sequencing and genotyping to analyze the genetics of hybrid indica-japonica rice in the region of a specific locus (S5) that had previously been shown to be involved in sterility in hybrids. They then compared their findings with genes in that region in other rice varieties, including Nanjing 11 (a subspecies of indica), Balilla (subspecies of japonica), and varieties producing fertile crossbred offspring: Dular and 02428. © 2012 Phys.orgcenter_img Explore further More information: A Killer-Protector System Regulates Both Hybrid Sterility and Segregation Distortion in Rice, Science, 14 September 2012: Vol. 337 no. 6100 pp. 1336-1340. DOI: 10.1126/science.1223702ABSTRACTHybrid sterility is a major form of postzygotic reproductive isolation that restricts gene flow between populations. Cultivated rice (Oryza sativa L.) consists of two subspecies, indica and japonica; inter-subspecific hybrids are usually sterile. We show that a killer-protector system at the S5 locus encoded by three tightly linked genes [Open Reading Frame 3 (ORF3) to ORF5] regulates fertility in indica-japonica hybrids. During female sporogenesis, the action of ORF5+ (killer) and ORF4+ (partner) causes endoplasmic reticulum (ER) stress. ORF3+ (protector) prevents ER stress and produces normal gametes, but ORF3– cannot prevent ER stress, resulting in premature programmed cell death and leads to embryo-sac abortion. Preferential transmission of ORF3+ gametes results in segregation distortion in the progeny. These results add to our understanding of differences between indica and japonica rice and may aid in rice genetic improvement. Early agricultural piracy informs the domestication of rice Citation: Researchers identify sterility genes in hybrid rice (2012, September 14) retrieved 18 August 2019 from This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

When green turns toxic Norwegians study Electric Vehicle life cycle

first_img Citation: When green turns toxic: Norwegians study Electric Vehicle life cycle (2012, October 5) retrieved 18 August 2019 from This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Normalized impacts of vehicle production. Results for each impact category have been normalized to the largest total impact. Global warming (GWP), terrestrial acidification (TAP), particulate matter formation (PMFP), photochemical oxidation formation (POFP), human toxicity (HTP), freshwater eco-toxicity (FETP), terrestrial eco-toxicity (TETP), freshwater eutrophication (FEP), mineral resource depletion (MDP), fossil resource depletion (FDP), internal combustion engine vehicle (ICEV), electric vehicle (EV), lithium iron phosphate (LiFePO4), lithium nickel cobalt manganese (LiNCM), coal (C), natural gas (NG), European electricity mix (Euro). Credit: (c) Journal of Industrial Ecology, DOI: 10.1111/j.1530-9290.2012.00532.x Explore further The “supply chain” part of the statement is key to the focus of their research. The electric car has been promoted heavily as a car for the future but quick takes on EVs as environmental vehicles of choice should be replaced with longer and careful looks, even oversight, at what occurs during the entire cradle-to-gate life cycle of a car’s production, use, and dismantling.Light-duty vehicles account for approximately 10 percent of global energy use and greenhouse gas (GHG) emissions and policy makers have braced themselves for what that means in climate change and air quality. In the Norwegian study, the authors looked at conventional and electric vehicles to see how all phases, from production to use to dismantling, affect the environment. They concluded that, “Although EVs are an important technological breakthrough with substantial potential environmental benefits, these cannot be harnessed everywhere and in every condition. Our results clearly indicate that it is counterproductive to promote EVs in areas where electricity is primarily produced from lignite, coal, or even heavy oil combustion.”The authors warned that the “elimination of tailpipe emissions at the expense of increased emissions in the vehicle and electricity production chains” carries risks for policy makers and stakeholders. The authors support serious attention to “life cycle” thinking. Their research was partly funded by the Norwegian Research Council under the E-Car ProjectEarlier this year, reports of a study of vehicle types in China concluded that electric cars have an overall impact on pollution that could be more harmful to health than conventional vehicles. The researchers in that study examined pollution in 34 Chinese cities and they found that the electricity generated by power stations to drive electric vehicles led to more fine particle emissions than petrol-powered transport. They analyzed five vehicle types—gasoline and diesel cars, diesel buses, e-bikes and e-cars. (—Questioning thoughts arise from a bracing study from Norway. The electric car might be a trade-in of an old set of pollution problems for a new set. Thanks but no thanks to a misguided cadre selling on the green revolution. Electric cars will eventually be one more pollutant source to campaign over. The study, “Comparative Environmental Life Cycle Assessment of Conventional and Electric Vehicles,” appears in the Journal of Industrial Ecology. Researchers from the Norwegian University of Science and Technology declared in the study that “EVs exhibit the potential for significant increases in human toxicity, freshwater eco-toxicity, freshwater eutrophication, and metal depletion impacts, largely emanating from the vehicle supply chain.” China’s pollution related to E-cars may be more harmful than gasoline cars, researchers find More information: Comparative Environmental Life Cycle Assessment of Conventional and Electric Vehicles, Troy R. Hawkins, Bhawna Singh, Guillaume Majeau-Bettez, Anders Hammer Strømman, Journal of Industrial Ecology, Article first published online: 4 OCT 2012. DOI: 10.1111/j.1530-9290.2012.00532.xAbstractElectric vehicles (EVs) coupled with low-carbon electricity sources offer the potential for reducing greenhouse gas emissions and exposure to tailpipe emissions from personal transportation. In considering these benefits, it is important to address concerns of problem-shifting. In addition, while many studies have focused on the use phase in comparing transportation options, vehicle production is also significant when comparing conventional and EVs. We develop and provide a transparent life cycle inventory of conventional and electric vehicles and apply our inventory to assess conventional and EVs over a range of impact categories. We find that EVs powered by the present European electricity mix offer a 10% to 24% decrease in global warming potential (GWP) relative to conventional diesel or gasoline vehicles assuming lifetimes of 150,000 km. However, EVs exhibit the potential for significant increases in human toxicity, freshwater eco-toxicity, freshwater eutrophication, and metal depletion impacts, largely emanating from the vehicle supply chain. Results are sensitive to assumptions regarding electricity source, use phase energy consumption, vehicle lifetime, and battery replacement schedules. Because production impacts are more significant for EVs than conventional vehicles, assuming a vehicle lifetime of 200,000 km exaggerates the GWP benefits of EVs to 27% to 29% relative to gasoline vehicles or 17% to 20% relative to diesel. An assumption of 100,000 km decreases the benefit of EVs to 9% to 14% with respect to gasoline vehicles and results in impacts indistinguishable from those of a diesel vehicle. Improving the environmental profile of EVs requires engagement around reducing vehicle production supply chain impacts and promoting clean electricity sources in decision making regarding electricity infrastructure. © 2012 Phys.orglast_img read more

Researchers create reusable adhesive that liquefies under UV light

first_imgThe AIRT representative at the show noted that the material does not undergo a reaction where new bonds form and are broken as it moves between a liquid and solid state, instead, an isomerization reaction occurs where the shape of the material itself changes. Because of that, the material can be used over and over again without losing its characteristics. They also noted that the speed of the reaction varies depending on the amount of light applied. Also, to cause the material to liquefy, the light used must be in the range 365 nm to 385 nm. To cause it to harden, the material can be exposed to ordinary light, as it contains light in the green range. This is the slow way, they say—using a green light, speeds up the process dramatically—a film 10 microns thick, for example, would take about 2 minutes to harden under a 80mW light source. It’s important to note, they add, that the change occurs due to light only—no heat is required to cause it to come about. They add that the adherence strength of the material is roughly equivalent to double-sided tape.AIRT believes the new material might be useful in manufacturing applications, where parts need to be held together temporarily while work is done, than released. Other applications might be more difficult to implement due to the necessity of working with transparent materials that allow light to pass through to the adhesive. Company reps say their engineers are continuing to study the material to see if its adhesive strength might by increased, and to find a way to change its color. Explore further Engineers from AIRT demonstrated the material at NanoTech 2013, currently running in Tokyo. The material was first presented as a powdered solid. Shining UV light on it causes it to liquefy where it can be applied to a surface. Once in place, shining a green light on it causes it to become hard, bonding two pieces of material together. In the demonstration, two small glass plates were “glued” together using nothing but the material and UV light—they were subsequently “unglued” by shining a green light at the point of connection. In addition to changing between liquid and solid states, the material also changes color. It’s yellow as a solid, but turns orange as it liquefies. (—Researchers at Japan’s National Institute of Advanced Industrial Science and Technology, (AIRT) have developed an organic material that can be liquefied or hardened by shining different types of light on it. The result is an adhesive that can be used over and over again. © 2013 More information: via Citation: Researchers create reusable adhesive that liquefies under UV light (2013, February 8) retrieved 18 August 2019 from This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Researchers create elastic material that changes color in UV lightlast_img read more

Defects in 2D semiconductors could lead to multicolored lightemitting devices

first_img The researchers, led by Sefaattin Tongay, Joonki Suh, and J. Wu, at the University of California, Berkeley, the Chinese Academy of Sciences in Beijing, and MIT, have published their paper on the effects of point defects on 2D semiconductors in a recent issue of Nature’s Scientific Reports.”Typically, defects in materials are considered something not wanted,” Tongay told “On the contrary, most of the functionalities of the materials are enabled by various imperfections such as defects. In this work, we show that engineering the defects in two-dimensional materials allows us to create another light emission channel and also enhance the light emission. “This is likely to be a milestone in the field. We scientists did not know how to observe defects by optical methods, and here we have found the first signatures of defects in 2D semiconductors. That’s exciting. Apparently, defects are another way to tune/activate the material’s properties on-demand.”While the physics of point defects in 3D semiconductors has been widely studied, much less is known about point defects in the more recently developed 2D semiconductors. The low-dimensional electronic systems are highly susceptible to disorder and imperfections. In 2D semiconductors, this propensity is expected to strongly influence electronic and excitonic processes. One such type of newly emerging 2D semiconductor is monolayer transition metal dichalcogenides (TMDs). Because TMDs have direct band gaps, meaning electrons can directly emit photons, they are promising light-emitting materials. Here, the scientists found that removing chalcogen (sulfur) atoms from a 0.7-nm-thick sample of the TMD MoS2 significantly changes its optical properties. As the number of defects in the material increases, the overall brightness of the light that is emitted by the material increases. This light has a photoluminescence peak at 1.90 eV, which determines its wavelength and color. But the defects also created a new photoluminescence peak at 1.78 eV. Citation: Defects in 2D semiconductors could lead to multi-colored light-emitting devices (2013, September 13) retrieved 18 August 2019 from This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. © 2013 Explore further , Scientific Reports More information: Sefaattin Tongay, et al. “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons.” Scientific Reports. DOI: 10.1038/srep02657center_img Journal information: Nature The photoluminescence spectrum at 77K for pristine MoS2 and MoS2 with defects created by two different irradiation doses. The defects enhance the intensity of the original photoluminescence peak (X0) as well as create a new peak (XB). Credit: Tongay, et al. ©2013 Nature Scientists enhance light emission in 2D semiconductors by a factor of 100 The scientists found that this lower energy peak dominates the photoluminescence spectrum at low temperatures, and becomes weaker as the temperature increases until it completely disappears above 250 K (-23 °C). However, at room temperature, the presence of such defects enhances the light emission. This observation goes against the conventional wisdom in the new field of 2D semiconductors, which has been that optical emission intensity at room temperature is sufficient criteria for assessing the crystal quality of 2D semiconductors; the results here suggest that assessments of crystal quality should involve low-temperature photoluminescence measurements.The scientists also demonstrated that vacancy defects have similar effects on the optical properties of two other TMDs, MoSe2 and WSe2. These results indicate that the effects of point defects are likely universal in other 2D semiconductors, as well.The researchers propose that the underlying mechanism of these effects depends on the interaction of the defect sites with nitrogen gas in the air. In vacuum, the defects did not have any effect on the TMDs’ optical properties. The scientists explain that N2 molecules in the air may drain free electrons from the material at the defect sites, which results in a greater proportion of free excitons (electrons bound to holes) in the material. Some portion of the free excitons then get trapped and bound by the defect vacancies, forming bound excitons. Eventually, both free and bound excitons recombine radiatively and yield two distinct light emission peaks at 1.90 eV (~650 nm) and 1.78 eV (~700 nm), respectively. Since researchers can create these defects by irradiation or thermal annealing, the defect density—and the resulting changes in the material’s optical properties—can be controlled via defect engineering. This ability could lead to the production of 2D semiconductors with multiple bandgaps, multi-colored light-emission devices, and optical gas sensors, among other applications.”With a smart design, point-defective 2D semiconductors potentially show better materials performance, which can be realized by uncovering defect physics in 2D systems,” Suh said. “That’s our team’s ultimate goal!” When scientists remove individual atoms in a semiconductor material, the resulting vacancies become point defects. Contrary to what their name implies, these defects can have beneficial effects on the semiconductor’s properties and enable most functionalities of electronic materials. In a new study, researchers have demonstrated that point defects in 2D semiconductors result in an increase in the overall room-temperature photoluminescence intensity. Further, the defects create a new emission peak that could lead to a better understanding of defect physics in 2D semiconductors as well as future applications such as multi-colored light-emitting devices.last_img read more

Sodium selective DNAzyme sensor

first_img Journal information: Proceedings of the National Academy of Sciences © 2015 However, studying sodium in real-time in living cells has proved difficult. Most biological fluorescence sensors are not selective for sodium, often binding to potassium, or are not feasible in a cellular environment, requiring organic solvents. Other applications cannot provide real-time data. A team from the Departments of Biochemistry, Chemistry, and Materials Science and Engineering at the University of Illinois at Urbana-Champaign has devised a biological fluorescent sensor that is selective for sodium ions and has demonstrated its ability to sense sodium in living cells. Their work was recently published in the Proceedings of the National Academy of Sciences.The University of Illinois team took advantage of recent developments in developing deoxy-ribozymes, or DNAzymes. DNAzymes are a kind of catalytic DNA that is obtained in the lab using a high throughput selection process. Prior research has demonstrated how DNAzymes can be used as metal ion sensors by designing them to have fluorescent labels that are only “turned on” when the DNAzyme binds the target metal and catalyzes enzymatic reactions. While these studies have demonstrated DNAzymes that can bind monovalent ions, such as Na+ or K+, thus far they have not been selective for sodium over potassium. The University of Illinois team identified and tested a DNAzyme that is more than 1,000-fold selective for sodium ion over other metals. Furthermore, their DNAzyme can detect sodium concentrations that are within the range typically seen in cells (0.135-50mM), and their detection method is fast enough that real-time studies can be conducted.DNAzymes can be converted to a fluorescent sensor by placing a fluorophore on one portion of the DNAzyme and a fluorescence quencher on another potion. As long as the fluorophore and the quencher are in contact, only background fluorescence is observed. Once the DNAzyme binds the target metal ion, Na+ in this case, it initiates cleaving a loop of DNA at a particular nucleotide, releasing the substrate portion with the fluorophore. It is separated from the quencher resulting in a fluorescent signal. New test for germs: Fluorescing DNAzymes detect metabolic products from bacteria Citation: Sodium selective DNAzyme sensor (2015, May 11) retrieved 18 August 2019 from Scheme of the decaging process for the photolabile Na+-specific DNAzyme. Credit: (c) 2015 PNAS, doi: 10.1073/pnas.1420361112 Explore further More information: “In vitro selection of a sodium-specific DNAzyme and its application in intracellular sensing” PNAS, DOI: 10.1073/pnas.1420361112AbstractOver the past two decades, enormous progress has been made in designing fluorescent sensors or probes for divalent metal ions. In contrast, the development of fluorescent sensors for monovalent metal ions, such as sodium (Na+), has remained underdeveloped, even though Na+ is one the most abundant metal ions in biological systems and plays a critical role in many biological processes. Here, we report the in vitro selection of the first (to our knowledge) Na+-specific, RNA-cleaving deoxyribozyme (DNAzyme) with a fast catalytic rate [observed rate constant (kobs) ∼0.1 min−1], and the transformation of this DNAzyme into a fluorescent sensor for Na+ by labeling the enzyme strand with a quencher at the 3′ end, and the DNA substrate strand with a fluorophore and a quencher at the 5′ and 3′ ends, respectively. The presence of Na+ catalyzed cleavage of the substrate strand at an internal ribonucleotide adenosine (rA) site, resulting in release of the fluorophore from its quenchers and thus a significant increase in fluorescence signal. The sensor displays a remarkable selectivity (>10,000-fold) for Na+ over competing metal ions and has a detection limit of 135 µM (3.1 ppm). Furthermore, we demonstrate that this DNAzyme-based sensor can readily enter cells with the aid of α-helical cationic polypeptides. Finally, by protecting the cleavage site of the Na+-specific DNAzyme with a photolabile o-nitrobenzyl group, we achieved controlled activation of the sensor after DNAzyme delivery into cells. Together, these results demonstrate that such a DNAzyme-based sensor provides a promising platform for detection and quantification of Na+ in living cells. (—Sodium ions are key regulators in cellular processes. The fluids in cells, whether it is water, blood plasma, or nutrients, are regulated by the sodium concentration in cells. If scientists could study sodium ions within a live cell, they would gain important insights into cellular processes including ways to reprogram these processes for biotechnological applications. DNAzymes are determined by subjecting a library of synthetic DNA candidates to in vitro binding studies using column-based and gel-based selection methods. Potential candidates are then amplified and tested until an optimal candidate is determined. Through this selection and amplification process, this group found a DNAzyme, labeled NaA43, that was selective for Na+. The next step was to make the fluorescent label. Every DNAzyme has two segments, the substrate and the enzyme strand. For this experiment, as NaA43S and NaA43E are the substrate and enzyme, respectively. The 5′ end of NaA43S was labeled with a known fluorophore, and a quencher was placed at its 3’end. An additional quencher was added to the 3′ end to ensure a minimal amount of background fluorescence. When Na+ was added, NaA43S was cleaved at the target nucleotide, and the fluorophore was released from quenchers. The result was an increase in fluorescent signal. Furthermore, fluorescence did not significantly change when twenty-two other metal ions were tested.Finally, the DNAzyme needed to be prepared for cellular insertion and detection. The process of delivering the DNAzyme into the cell could result in premature cleavage, so this team employed “photocaging” to control when the substrate was cleaved. Photocages are photoactive molecules that are placed at the cleavage site to prevent DNA substrate cleavage. When light at a certain wavelength is irradiated at the site, the photo-caged group is released, and then the substrate can be cleaved.Finally, in order to transport the DNAzyme through the cell membrane and into the cytosol, they used a class of alpha-helical cationic polypeptide that is known to facilitate transportation through the cell membrane. After four-hour incubation into living HeLa cells, NaA43ES was found to be located predominately in the cytosol and did not accumulate in other organelles. The cleavage site was “uncaged” by irradiating the cell with light (365 nm) for thirty minutes. Then they enhanced the sodium levels in the cells. As sodium ions traveled from the extracellular matrix to within the cell, fluorescence measurements increased during this time, demonstrating intracellular Na+ detection in living cells.This work reports the first use of a DNAzyme to make a real-time, selective sodium ion sensor that can be used in living cells. Since sodium selectivity has been difficult to achieve, and these studies will not only allow for additional studies on cellular activity but may also shed light on ion selectivity, in general. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

Curtains down

first_imgThe 15 days of cultural festivity in the city comes to an end today. The Seventh Edition of Delhi International Arts Festival organized by Prasiddha foundation and Ministry of Culture, Govt of India witnessed performances of different regions with a touch of both national and international colours.  The concept was conceived by Prathibha Prahlad 7 years back.DIAF started with a magnificent performance by the Pung Cholam from Manipur, Langas & Manganiars from Rajasthan, Hety & Zambo from Columbia, National Troupe of Folk Arts from Egypt, Rouf Dance from Kashmir and Traditional Dance from Srilanka at Purana Qila on 8th February. The festival witnessed enthralling shows and performances like the Visual Arts and Crafts exhibition, Pran & Farooq Shaikh Restrospective, a film festival to pay tribute to the legendary actors, Hollywood & Children’s Film Festival, Kalaripayattu Martial Arts from Kerala, Magic show by Spanish magician Murray Molloy, Dhrupad music. Also Read – ‘Playing Jojo was emotionally exhausting’Each year DIAF brings every genre of performing and visual arts ranging from the classical to the contemporary from across the world.  DIAF 2014 brought performances from remote parts of Kerala, Assam, Jharkhand, Bihar, West Bengal, Bihar and several others. Literature events included panel, discussions and talks at the Sahitya Akademi, Iranian illumination artistes and craftsmen who demonstrated their works at the National Museum and the Crafts Museum. It was an extraordinary time for the art and culture lovers of Delhi. Classical music lovers witnessed Dhrupad Festival which featured musicians from all over India like Ustad Wasiffudin Dagar, Ustad Hussain Sayeeduddin Dagar, Pandit Uday Bhawalkar and others. Theatre enthusiasts enjoyed the staging of Abhignana Shakuntala directed by KN Pannikar at the National School of Drama and a Spanish Play Holiday Out at the Institute of Cervantes.The gala closing took place at the Indira Gandhi National Centre for the Arts Lawns with a soulful Sufi and Qawwali by Barkat Sidhu from Punjab and Nazir Ahmed Khan Warsi & Naseer Ahmed Khan Warsi from Hyderabad.last_img read more

Handicapped city

first_img23-year-old Abhinav Nagar set out to explore this Christmas charm a couple of years ago in and around St James’ Church in Kashmere Gate, known to be the oldest surviving church in Delhi. Accompanying him were his three friends, all students from the same college, nurturing generous dreams of a grand future full of accomplishments. Nagar remembers chatting amiably with his friends and enjoying the cool breeze and the Christmas air. But what happened next changed their lives forever. Also Read – Find your own happinessThere was total blackness as a cow darted in front of their vehicle, forcing Nagar to lose control of the car completely and crash into a nearby lamp-post on the pavement. He hit his spine instantly and his friends were injured too. Nagar woke up the next day in hospital. He could not move either of his legs and his doctor told him that he could never walk again. At 23, Abhinav became wheelchair-bound, overnight, and his life changed forever.This is not an isolated case of compulsive disability. There are hundreds and thousands of people all over the world witnessing their lives change all of a sudden due to a mishap, accident or some disease. But what we, the other half of the population who can walk, run, jump and enjoy life and every bit of it, do not realise is the pain these people experience everyday to walk that extra mile which once seemed impossible. Also Read – Into the wildThere are ambitions plans to turn Delhi into a smart city. But our national Capital is thoroughly devoid of a disabled-friendly infrastructure and basic sensitivity essential to make this place accessible to them too. There is a gross negativity prevailing for the differently-abled, who are always subjected to mercy of others for any kind of help or acceptance. It would thus be a great idea to create an infrastructure or give them an ambience that would not make it imperative for them to move around with someone else’s help or acceptance. A recently conducted study reveals that some of the city’s busiest places like Connaught Place, Lodhi Road, Sarai Kale Khan and Nehru Place are devoid of street infrastructure for the differently-abled and even for the elderly to navigate. These places are even inaccessible for those with reduced mobility, pregnant women, children, persons carrying luggage and those with temporary ailments. Some of the key problems found at Connaught Place were lack of proper signages and audio signals, non-continuity of tactile pavers and pelican crossings. Footpath height and width varied at many places and there was lack of kerb ramps and pedestrian crossings in front of busy bus terminuses like the ISBT, coupled with open drains on footpaths and encroachments by hawkers.Abha Khetarpal, president of NGO Cross the Hurdles says: “Essential services like banks, ATMs, post offices still remain inaccessible for the differently-abled. Even many of the doctors’ clinics and diagnostic centres are not disabled friendly. Schools do not have proper infrastructure to accommodate students with disabilities. Though public buildings, many stadiums might have ramps for wheelchair users to enter the premises but washrooms inside the campus are inaccessible. Personally speaking, I have found no washrooms for disabled people at Thyagraj stadium near INA market that was built as a venue for the 2010 Commonwealth Games.”She further elaborates: “Movie theatres again are not friendly. ‘Disabled friendly’ does not mean just a ramp being made outside the premises for wheelchair users. It must cater to the needs to all the different kind of disabilities. Tactile surfaces and Braille signage are rarely found. Many hotels and restaurants still remain unfriendly.”The differently-abled also face insensitive behaviour of bus drivers and conductors, who many a times charge more than the designated fare, despite travel for the visually impaired being free in all state-run Delhi Transport Corporation (DTC) buses and the National Capital Region (NCR). But statistics show that this is not restricted to Delhi or the NCR area alone. The 70 million disabled in India face similar problems in other parts of the country too and, possibly, things are much worse. Transportation in every Indian city and town has failed disabled citizens to live a smooth and uncomplicated life. Lack of awareness, contempt and lapsed policies contribute to their plight. Though low floor buses in several metropolises including Delhi are initiatives for making transportation smooth, it has hardly come as a boon.Javed Abidi, director, National Centre for Promotion of Employment for Disabled People in India mentions in a report: “Despite it being a norm, there are no ramps to get on to the bus stands in the national capital. It’s a shame that the DTC plays hoax on us by painting disabled-friendly pictures and signages at bus stops, as they never practice what they preach.” Unfortunately, there has been little done in this direction to address the issue.Khetarpal adds: “No railway station in Delhi has a lift. Though the bus stops show the universal symbol of disability has broken ramps or are just unreachable due the rugged surfaces or the large number of street vendors and hawkers.”Though many new pavements and sidewalks in most New Delhi Municipal Council and Municipal Corporation of Delhi (MCD) areas are spacious and well-laid, many of them are blocked by bollards or small iron posts through which a wheelchair can’t pass.According to disabled rights organisations, the special ramps constructed on many roads have faulty designs and do not follow international standards. Ideally, for a height of one metre the ramps should be 18 metres long (1:18 gradient). But the ramps are built on a 1:12 gradient and are steep. Moreover, they also do not provide a landing after every five metres. Even the parks in the national capital are not disabled-friendly. Summed together, there are as many as 14,000 parks in total but all of them more or less lie in a state of shambles and do not support visitors with disabilities. However, Mukesh Yadav, Public Relations Officer (PRO) of South MCD says: “Almost all our parks are disabled-friendly. All of them are at the ground level so there is particularly no need for a ramp. Also, there is one gate at the entrance of every park through which a wheelchair can easily enter.” But in reality, the story is a little different.Kanika Dua, an MA Psychology student in Delhi University who is partially visually impaired, says: ‘I’m very lucky that the crowd in my university is very good. People do help and try to understand our problems. Cops are very helpful. But when I go out of the campus, it is a little difficult as I don’t know all the roads, there are no Braille signages and mobility becomes an issue.’The Delhi Metro, often referred to as the lifeline of the national Capital, and rightly so, has stood the test of time in the last decade regarding performance. There is little doubt that the Metro has contributed in no small measure to taking Delhi and its infrastructural facilities to the next level! But this is just one side of the picture. Delhi Metro does seem ill-prepared not just for emergencies but also when it comes to helping the disabled with wheelchairs. The number of wheelchairs and stretchers at one of the busiest stations Rajiv Chowk, is limited to only three and five respectively!Shopping arcades and malls in Delhi are considerably better in terms of providing a friendly ambience for the disabled. Sonali Manilal, Marketing Head, DLF Promenade says: “The mall has reserved parking for physically challenged and senior citizens in B1. The parking has been reserved next to the elevator lobby with dedicated parking attendants. For physically challenged patrons, the mall is equipped with a dedicated and customized hydraulic elevator; all prominent entrances have wheel chairs stationed with an attendant; each shopping floor houses washrooms for the disabled.” In case of an emergency, she adds: “The staff is well trained in basic life saving skills and safety trainings. There is a medical room with bed and important medical equipment. The concierge is trained to use basic medical techniques and is always equipped with medical kit.” But for the past few years, there is a growing political momentum behind the need to take disability provision seriously.If available figures are to be believed, people with disabilities are more likely to be unemployed, illiterate, to have less formal education and less access to support networks. They are further isolated by discrimination, ignorance and prejudice. The World Bank estimates that about 20 per cent of the world’s poorest people are disabled. Poverty causes disability through inadequate access to medical treatment and vaccinations, and exposure to unsanitary and unsafe living and working conditions. Children with disabilities in India rarely progress beyond primary education, with school enrolment less than 10 per cent in many areas. This then reinforces social alienation and leads to very limited employment opportunities, leading to abject poverty. A universal barrier-free environment is every Indian’s dream. Reassuringly, a few have been lobbying for it for some time now, working towards creating and maintaining environments in which all people can participate in ways that are equitable, dignified, independent and safe for all. Obstacles of any kind affect the lives of people to a great extent, and it is not difficult to imagine the plight of millions of disabled people who face hurdles at every single step.last_img read more