Report suggests more rigorous assessment of nanosilver use

first_img More information: Nanosilver Revisited Downstream, Bernd Nowack, Science 19 November 2010: Vol. 330 no. 6007 pp. 1054-1055. DOI:10.1126/science.1198074 These hand sanitizers and many other consumer products on the market contain nanosilver. Nanosilver is the most commonly used nanoparticle found in consumer goods, and is being used as an anti-odor, antibacterial agent in fabrics, deodorants, toothpastes, and even cement. It is also found in a wide range of other applications, including paints, medical devices, bandages, food containers, and electronics equipment and washing machines. Silver is widely used because it is believed to be harmless to humans except in high concentrations, but it is known to be toxic to fungi, bacteria and other microorganisms, and little is known about its effects on wastewater systems or the wider environment. Previous studies in Europe have shown that around 15 percent of the total volume of silver in wastewater is biocidal nanosilver originating in consumer goods and medicinal uses.Author of the report, Dr. Bernd Nowack of the Swiss Federal Laboratory for Materials Science, Empa, said that while silver has long been known to be a biocide, nanosilver seems to have unique properties because of the nano-scale (less than 100 billionths of a meter) size of the particles. He said this suggests there should be more rigorous assessments of the risks to humans and the environment.Dr. Nowack said one of the risks arises because some of the wastewater and sludge from sewage treatment plants ends up on farms in fertilizers, and could therefore enter the food chain. Another risk is that nanosilver could have a detrimental effect on the nitrifying bacteria that are vital to the effluent treatment processes, and could prevent treatment plants from working properly.Nowack’s report said in earlier studies some nanosilver had been shown to bond with sulfur in sewage sludge to produce non-toxic silver sulfide nanoparticles, but it is not known how efficient sulfur is at removing biocidal silver.In the US and many other countries manufacturers have no obligation to disclose the presence of nanoparticles in consumer goods. Citation: Report suggests more rigorous assessment of nanosilver use (2010, November 22) retrieved 18 August 2019 from Popular nanoparticle causes toxicity in fish, study shows ( — A new report published in the journal Science suggests the risks to the environment of nanosilver used in consumer goods should be examined more stringently. © 2010 Explore further 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

Inspector General audit finds problems with NASAs cloud computing efforts

first_img © 2013 Citation: Inspector General audit finds problems with NASA’s cloud computing efforts (2013, July 30) retrieved 18 August 2019 from CIA faulted for choosing Amazon over IBM on cloud contract Explore further Over the past several years, the Office of Management and Budget, which controls the purse strings of federal entities, has demanded that governmental agencies, such as NASA, begin transferring some or all of its data processing and storage activities to the cloud. The idea is that doing so will save the government a lot of money. In following the directive, however, it appears that managers at NASA have failed to ensure that cloud operations are undertaken with the knowledge and approval of the agencies top information officer. Worse, it appears that many of the cloud initiatives were undertaken without due consideration given to necessary security precautions that must be put in place when applications and data become accessible across the Internet.More specifically, the auditors found over a 100 NASA websites—both internal and external—had never been tested for security integrity. Incredibly, many of those same websites were found to have no security controls in place at all.Government agencies have two main options when moving applications to the cloud—set up facilities on their own or contract out. NASA, like most other federal agencies has chosen the latter. Unfortunately, the auditors found that officials at the agency in many cases failed to include security issues when writing contracts, which of course resulted in them not being put in place.Overall, the IG’s report has found that weaknesses in cloud applications have impeded the agency from reaping the benefits of cloud computing—namely reducing costs. And worse, the approach taken thus far has put NASA data at risk. Out of five contracts reviewed, the auditors found “none came close” to operating with industry standard security precautions.The auditors recommend that NASA set up an office dedicated to cloud computing and the security issues that must be put in place when such initiatives are undertaken. 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. ( —The Office of the Inspector General, led by Paul Martin, has published the results of an audit of NASA’s cloud computing efforts and has found many such efforts lack proper security. The report also notes that many cloud efforts run by the agency were operating without the knowledge of its own Office of the Chief Information Officer.last_img read more

General principles to explain DNA brick selfassembly

first_imgControlled nucleation is essential for robust self-assembly. (A) An example 86-strand DNA-brick structure and (B) its associated connectivity graph. (C) Incidental interactions between dangling ends, shown in orange, lead to incorrect associations between fragments. Credit: (c) 2015 PNAS, DOI: 10.1073/pnas.1502210112 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. (—DNA bricks are an odd phenomenon. They are nanostructures built from synthetic, single-strand DNA that self-assemble into 3D structures. Several years ago, researchers at Wyss Institute at Harvard demonstrated the self-assembly of designed 3D structures made from 1,000 “bricks” that fit together like molecular Legos. One of the curiosities about these DNA bricks is why this complex self-assembly process works so well. Journal information: Proceedings of the National Academy of Sciences In an effort to uncover the nuances of DNA brick self-assembly, William M. Jacobs, Aleks Reinhardt, and Daan Frenkel from the University of Cambridge conducted theoretical studies to understand what drives the assembly process. Their studies reveal how temperature, kinetics, coordination number, and bond energies, contribute to the unique behavior of DNA brick self-assembly, and while it is a nucleated process, it does not behave according to classical nucleation theory. Their work appears in the Proceedings of the National Academy of Sciences.In order to optimize DNA brick assembly, Jacobs, et al. wanted to investigate whether these systems had a nucleation barrier. In classic nucleation theory (CNT), the nucleation barrier is the energy cost for making an ordered structure, such as a crystal. This energy barrier must be overcome before a compound can settle into its equilibrium structure. The authors found that DNA brick assembly does have a nucleation barrier, but, unlike CNT, this barrier is determined by the way the bricks are connected in the target structure. They identified several factors that contribute to this non-classical behavior.DNA bricks are designed to assemble in particular ways by matching certain sections of a DNA strand with a complimentary section. These designed interactions need to be stronger than incidental interactions. They found that there is a critical number of DNA strands that must be assembled to promote the formation of the target structure, meaning that the the nucleation barrier is a consequence of the number of subunits that must be assembled.Additionally, DNA-bricks have a certain temperature range at which the nucleation barrier is overcome, but over which the free energy of the final structure is higher than the initial monomers. This deviates from CNT which predicts that a nucleus with more than the critical number of DNA strands will assemble into the complete structure. This difference is due to DNA bricks forming stable intermediate structures. Experimentally, this means that self-assembly occurs in a narrow temperature range in which nucleation begins at a high temperature, and as the structure is gradually cooled, the target structure is favored.In prior studies, the maximum number of bonds made by each brick in the interior of a structure was four, but it is possible to have different coordination numbers. The question was whether the coordination number affected the nucleation barrier, and whether four bonds were necessary. It turns out that DNA brick self-assembly works well because each subunit makes only a small number of bonds. When the authors tested higher coordination numbers, they found that the system behaved analogously to CNT.Finally, Jacobs et al. found that contrary to theories that homogenous bond energies would decrease the number of errors during DNA brick assembly, it is the diversity in bond energies that contributes to enhanced kinetics of DNA brick self-assembly. This was likely due to stabilizing unstable intermediate structures.Jacobs, et al. have identified several key features that aid in understanding why DNA brick self-assembly works as well as it does. Features such as ramping down the temperature and optimizing the coordination number explain why there are so few errors in the self-assembly process. And, their discovery that heterogeneous bond energies promote target molecule formation is a practical place where researchers can improve yields and decrease errors in DNA brick assembly. More information: “Rational design of self-assembly pathways for complex multicomponent structures” PNAS, DOI: 10.1073/pnas.1502210112AbstractThe field of complex self-assembly is moving toward the design of multiparticle structures consisting of thousands of distinct building blocks. To exploit the potential benefits of structures with such “addressable complexity,” we need to understand the factors that optimize the yield and the kinetics of self-assembly. Here we use a simple theoretical method to explain the key features responsible for the unexpected success of DNA-brick experiments, which are currently the only demonstration of reliable self-assembly with such a large number of components. Simulations confirm that our theory accurately predicts the narrow temperature window in which error-free assembly can occur. Even more strikingly, our theory predicts that correct assembly of the complete structure may require a time-dependent experimental protocol. Furthermore, we predict that low coordination numbers result in nonclassical nucleation behavior, which we find to be essential for achieving optimal nucleation kinetics under mild growth conditions. We also show that, rather surprisingly, the use of heterogeneous bond energies improves the nucleation kinetics and in fact appears to be necessary for assembling certain intricate 3D structures. This observation makes it possible to sculpt nucleation pathways by tuning the distribution of interaction strengths. These insights not only suggest how to improve the design of structures based on DNA bricks, but also point the way toward the creation of a much wider class of chemical or colloidal structures with addressable complexity.last_img read more

Programming human cells to follow sets of logical instructions

first_img 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. (—A team of researchers at Boston University has developed a new way to engineer mammalian cells that allows for programming them to behave in desired ways. In their paper published in the journal Nature Biotechnology, the team describes their technique and where they believe such technology is heading. Explore further As scientists around the world look for new ways to prevent and treat diseases, new techniques are emerging, some of which involve programing human cells to behave in desired ways—such as killing cancer cells. In this new effort, the researchers have developed a new way to program mammalian cells using DNA recombinases.To learn how to program cells researchers have worked with simple organisms such as bacteria, which has led to the use of proteins called transcription factors that regulate genes. Unfortunately, that technique has proven unsuitable for programming mammalian cells because it does not produce the same results consistently in all environments. To get around that problem, the researchers instead chose to work with DNA recombinases—enzymes that can be used to cut DNA in predesignated ways and put them back together in new and useful ways.Cutting DNA and sewing it back together allows for programming cells because DNA controls which proteins a cell makes. By cutting and sewing in a certain way, the researchers were able to induce a human kidney cell to produce a fluorescent protein which caused the cell to light up under desired conditions. Inserting other snippets allowed for modifying recombinases that were activated only in the presence of a certain chemical. By cutting multiple DNA snippets, adding new ones and sewing them back together, the researchers found that they were able to create 113 unique circuits that demonstrated a 96.5 rate of success. In one instance, they created a bio-circuit that mimicked a Boolean lookup table—it had six inputs that allowed for executing 16 logical operations.The work by the team was a proof of concept, they’re optimistic that their technique could be used to create new therapies such as bolstering the immune system by programming T cells—perhaps causing them to attack tumor cells. Another possibility is using the technique to program stem cells to grow into desired tissue. New stem cell method produces millions of human brain and muscle cells in days Journal information: Nature Biotechnologycenter_img A depiction of the double helical structure of DNA. Its four coding units (A, T, C, G) are color-coded in pink, orange, purple and yellow. Credit: NHGRI More information: Benjamin H Weinberg et al. Large-scale design of robust genetic circuits with multiple inputs and outputs for mammalian cells, Nature Biotechnology (2017). DOI: 10.1038/nbt.3805AbstractEngineered genetic circuits for mammalian cells often require extensive fine-tuning to perform as intended. We present a robust, general, scalable system, called ‘Boolean logic and arithmetic through DNA excision’ (BLADE), to engineer genetic circuits with multiple inputs and outputs in mammalian cells with minimal optimization. The reliability of BLADE arises from its reliance on recombinases under the control of a single promoter, which integrates circuit signals on a single transcriptional layer. We used BLADE to build 113 circuits in human embryonic kidney and Jurkat T cells and devised a quantitative, vector-proximity metric to evaluate their performance. Of 113 circuits analyzed, 109 functioned (96.5%) as intended without optimization. The circuits, which are available through Addgene, include a 3-input, two-output full adder; a 6-input, one-output Boolean logic look-up table; circuits with small-molecule-inducible control; and circuits that incorporate CRISPR–Cas9 to regulate endogenous genes. BLADE enables execution of sophisticated cellular computation in mammalian cells, with applications in cell and tissue engineering. Citation: Programming human cells to follow sets of logical instructions (2017, March 29) retrieved 18 August 2019 from © 2017 Phys.orglast_img read more

Books and then some

first_imgThe 20th edition of Delhi Book Fair and 16th Stationery and Office Automation Fair at Pragati Maidan ended on 31 August. The last day of the event featured award giving ceremony by Rita Menon, Chairperson and Managing Director, India Trade Promotion Organisation (ITPO) for Excellence in Display.Awards were presented in different categories comprising Hindi, Regional and English languages. In Hindi language category, Prabhat Prakashan won the gold trophy, Kitabghar Prakashan won silver and Hindi Book Centre won bronze trophy while  in  the English language category, MBD Group, Full Marks Pvt. Ltd. and Amity University Press won the gold, silver and bronze trophies, respectively. Also Read – ‘Playing Jojo was emotionally exhausting’National Book Trust bagged the gold trophy and Sahitya Akademi won the silver trophy in the Regional language categories. Ballarpur Industries Limited bagged the gold trophy and Paper Theatre and GSC Glass Ltd. received the silver and bronze trophies, respectively, for Excellence in Display in the Stationery and Office Automation Fair. The event also witnessed a workshop on book review Let’s Review a Book and an interactive session-cum workshop with an illustrator for school children on 29 August organised by National Centre for Children’s Literature, a wing of National Book Trust. Also Read – Leslie doing new comedy special with NetflixThe programme was divided into two sessions. The first session on book review was conducted by Nandini Sahu, Associate Professor of English, IGNOU and creative writer. The second session was on illustration was conducted by Subir Roy, renowned illustrator and Art Director at Children’s Book Trust.While giving details on how to write a book review, Sahu said ‘The role of reviewer is very important as the reviewer tells the reader what the book is all about. Since the reviewer has the freedom to write about the book, his mind should be open and should not have negative approach towards the writer.’ In the second session, Roy gave an insight into designing a cover of the book. He informed children about the young Indian artistes who have won several awards at international level. Roy shared his experience as an illustrator and gave tips to children to draw good illustrations.More than 150 children from various schools of Delhi and NCR including DAV Public School Paschim Enclave, DAV Public School Shreshtha Vihar, Ahlcon Public School, Mayur Vihar, Shraddha Public School, Faridabad participated in this programme.The best twenty students in the workshop were given away awards and certificates. The next edition of the fair will be organised from 29 August to 6 September, 2015.last_img read more

Life is a mashup

first_imgNew DJ on the block DJ Chetas was in town at A State of Music (ASOM) Radisson Blu, Dwarka to give Delhi a heady taste of good old Bollywood music and his famous mashups. We had a word with him about it all. Here’s what he had to say…Tell us about yourselves. How did you start off?DJing started off as a hobby and will end also being a hobby cause my priority would always be my family business of road constructions. I started off playing for my friends private parties. Also Read – ‘Playing Jojo was emotionally exhausting’ What was the first big break for you?My first big break was with T-series and my remix for Aashiq Banaya Aapne at the age of 16 . How would you define your musical philosophy?  Tell us a bit about your music, what do you think defines you?Mashups have always been what I wanted to do. When I started making mashups, people, in fact even my close friends said that this concept would not work, but as you know today, everyone grooves  to mashups!How easy (or difficult) is it to make a mark in the music scene? What do you think about the main issues are? Also Read – Leslie doing new comedy special with NetflixIt’s not easy create you mark in the music scene, it’s a lot of hard work and dedication that goes in. Trying to get everyone like your track is the challenge, all though you can never please 100 per cent of the audience , that should always be your goal. What/Who inspires you? Family and friends and of course my team – Life is a mashup!  Tell us about your best tracksI think Balam Pichkari was my first massive remix , so that’s one, and the Break Up Mashup. These are tracks closest to my heart. What songs top your playlist right now?All Arijit Singh tracks . What suggestions/advice would you have for newbies in music?Follow your heart , do what you love , but also remember that music wont fill your stomach so its always good to have a backup job. How has Delhi been for you?Delhi’s like second home now, we are here at least twice or thrice a month.last_img read more

The Spanish dream

first_imgChef Moreno will present a beautifully crafted menu comprising of specialties from the Extremadura region, such as the famous Jamon Iberico pork, exceptional olive oil, fresh paprika and freshly sourced ingredients including soft sheep’s cheeses from the Serena and Casar. The menu includes regional favorites such as ‘Asparagus tempura with paprika flavoured potato foam’,’Coca Catalana with Green Olive Tartar and goat cheese’ and various dishes with Iberian cold cuts and meats.  The extravaganza will continue till December 6. Also Read – ‘Playing Jojo was emotionally exhausting’Extremadura in Spain is home to a National Park and several areas of outstanding natural beauty, especially in the north of the region. The Tapas festival in the city is organized with the support of Government of Extremadura and the Spanish Embassy with an aim to showcase the gastronomy of the region.Named after Seville, the famous art and cultural capital of southern Spain, Sevilla at The Claridges New Delhi is the city’s most recognised Mediterranean restaurant known for its new-style Spanish cuisine. The styling at Sevilla is inspired by the azure skies and landscape of the Mediterranean that creates a visual delight with the indoors and outdoors merging to provide a free flowing, casual dining experience reflecting the Spanish Riviera. The restaurant continues to win unprecedented praise and rave reviews for its innovative gastronomy from southern coastal Europe and Casablanca.last_img read more

Madrassa students to interact with Howrah cops over road safety

first_imgKolkata: Howrah city police is going to organise an awareness campaign in which students from Madrassas will be interacting with policemen, who are experts in traffic management, on a one-to-one basis, at Safe Drive Save Life Park. The move was taken considering it will help Madrassa students learn about road safety in details and they can circulate the message of safe drive save life among more people including their family members.A unique Park has been set up off Foreshore Road and it has been named after this statewide road safety campaign, ‘Safe Drive Save Life’, which was launched by Chief Minister Mamata Banerjee to check road accidents. Also Read – Heavy rain hits traffic, flightsHowrah city police has so far taken several initiatives to create awareness among people on road safety. A park has been set up beside Foreshore Road through which thousands of people pass everyday. The decorative pieces and paintings in the park, which were done based on the theme ‘Safe Drive Save Life’, attracts attention of all passersby and it creates awareness among people. A senior officer of Howrah city police said around 50 students from different Madrassas in Kolkata’s twin City will be participating in the programme that is going to be held at Save Drive Save Life Park on Saturday. Senior officers of Howrah city police including those who are mainly involved with regular traffic management and road safety issues will be present at the venue. As per the plan, the officers will be interacting directly with the students. First, they will give a brief description on road safety and traffic related matters to the students and subsequently they will also explain the aspects related to traffic management as per the queries of the students present. It may be mentioned that Kolkata Police, district police and all the police commissionerates under it have organised several awareness programmes in schools and colleges. Howrah Police is also involved in organising such programmes and students from different schools are already associated with road safety campaigns. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedNow, the students from Madrassas are also going to be a part of the campaign. The police officer said the knowledge they will gain during the interactive session on road safety will help them immensely and at the same time they will be able to spread the same message and knowledge among their close ones. This is how more number of people will become aware and eventually start to follow the traffic norms. Zafar Ajmal Kidwai, Deputy Commissioner of Police (Traffic) of Howrah City Police, said: “It is a continuous process. There will be awareness campaigns by students from Madrassas on Saturday at Safe Drive Save Life Park. Students from schools of all other mediums including Bengali and Hindi will also be brought under the programme.”last_img read more