Tag Archives: Italy

Synthesizing spider silk

Most of the research on spider silk and spider webs that’s featured here is usually from the Massachusetts Institute of Technology (MIT) and, more specifically, from professor Markus J. Buehler. This May 28, 2015 news item on ScienceDaily, which heralds the development of synthetic spider silk, is no exception,

After years of research decoding the complex structure and production of spider silk, researchers have now succeeded in producing samples of this exceptionally strong and resilient material in the laboratory. The new development could lead to a variety of biomedical materials — from sutures to scaffolding for organ replacements — made from synthesized silk with properties specifically tuned for their intended uses.

The findings are published this week in the journal Nature Communications by MIT professor of civil and environmental engineering (CEE) Markus Buehler, postdocs Shangchao Lin and Seunghwa Ryu, and others at MIT, Tufts University, Boston University, and in Germany, Italy, and the U.K.

The research, which involved a combination of simulations and experiments, paves the way for “creating new fibers with improved characteristics” beyond those of natural silk, says Buehler, who is also the department head in CEE. The work, he says, should make it possible to design fibers with specific characteristics of strength, elasticity, and toughness.

The new synthetic fibers’ proteins — the basic building blocks of the material — were created by genetically modifying bacteria to make the proteins normally produced by spiders. These proteins were then extruded through microfluidic channels designed to mimic the effect of an organ, called a spinneret, that spiders use to produce natural silk fibers.

A May 28, 2015 MIT news release (also on EurekAlert), which originated the news item, describes the work in more detail,

While spider silk has long been recognized as among the strongest known materials, spiders cannot practically be bred to produce harvestable fibers — so this new approach to producing a synthetic, yet spider-like, silk could make such strong and flexible fibers available for biomedical applications. By their nature, spider silks are fully biocompatible and can be used in the body without risk of adverse reactions; they are ultimately simply absorbed by the body.

The researchers’ “spinning” process, in which the constituent proteins dissolved in water are extruded through a tiny opening at a controlled rate, causes the molecules to line up in a way that produces strong fibers. The molecules themselves are a mixture of hydrophobic and hydrophilic compounds, blended so as to naturally align to form fibers much stronger than their constituent parts. “When you spin it, you create very strong bonds in one direction,” Buehler says.

The team found that getting the blend of proteins right was crucial. “We found out that when there was a high proportion of hydrophobic proteins, it would not spin any fibers, it would just make an ugly mass,” says Ryu, who worked on the project as a postdoc at MIT and is now an assistant professor at the Korea Advanced Institute of Science and Technology. “We had to find the right mix” in order to produce strong fibers, he says.

The researchers made use of computational modelling to speed up the process of synthesizing proteins for synthetic spider silk, from the news release,

This project represents the first use of simulations to understand silk production at the molecular level. “Simulation is critical,” Buehler explains: Actually synthesizing a protein can take several months; if that protein doesn’t turn out to have exactly the right properties, the process would have to start all over.

Using simulations makes it possible to “scan through a large range of proteins until we see changes in the fiber stiffness,” and then home in on those compounds, says Lin, who worked on the project as a postdoc at MIT and is now an assistant professor at Florida State University.

Controlling the properties directly could ultimately make it possible to create fibers that are even stronger than natural ones, because engineers can choose characteristics for a particular use. For example, while spiders may need elasticity so their webs can capture insects without breaking, those designing fibers for use as surgical sutures would need more strength and less stretchiness. “Silk doesn’t give us that choice,” Buehler says.

The processing of the material can be done at room temperature using water-based solutions, so scaling up manufacturing should be relatively easy, team members say. So far, the fibers they have made in the lab are not as strong as natural spider silk, but now that the basic process has been established, it should be possible to fine-tune the materials and improve its strength, they say.

“Our goal is to improve the strength, elasticity, and toughness of artificially spun fibers by borrowing bright ideas from nature,” Lin says. This study could inspire the development of new synthetic fibers — or any materials requiring enhanced properties, such as in electrical and thermal transport, in a certain direction.

Here’s a link to and a citation for the paper,

Predictive modelling-based design and experiments for synthesis and spinning of bioinspired silk fibres by Shangchao Lin, Seunghwa Ryu, Olena Tokareva, Greta Gronau, Matthew M. Jacobsen, Wenwen Huang, Daniel J. Rizzo, David Li, Cristian Staii, Nicola M. Pugno, Joyce Y. Wong, David L. Kaplan, & Markus J. Buehler. Nature Communications 6, Article number: 6892 doi:10.1038/ncomms7892 Published 28 May 2015

This paper is behind a paywall.

My two most recent (before this one) postings about Buehler’s work are an August 5, 2014 piece about structural failures and a June 4, 2014 piece about spiderwebs and music.

Finally, I recognized one of the authors, Nicola Pugno from Italy. He’s been mentioned here more than once in regard to his biomimicry work which has often been focused on geckos and their adhesive qualities as per this April 3, 2014 post announcing his book ‘An Experimental Study on Adhesive or Anti-Adhesive, Bio-Inspired Experimental Nanomaterials‘ (co-authored with Emiliano Lepore).

Nanobionic plant materials

This is a bioinspired story with a bit of a twist. From a March 30, 2015 news item on Nanowerk (Note: A link has been removed),

Humans have been inspired by nature since the beginning of time. We mimic nature to develop new technologies, with examples ranging from machinery to pharmaceuticals to new materials. Planes are modelled on birds and many drugs have their origins in plants. Researchers at the Department of Mechanical and Process Engineering [ETH Zurich; Swiss Federal Institute of Technology] have taken it a step further: in order to develop an extremely sensitive temperature sensor they took a close look at temperature-sensitive plants. However, they did not mimic the properties of the plants; instead, they developed a hybrid material that contains, in addition to synthetic components, the plant cells themselves (“Plant nanobionic materials with a giant temperature response mediated by pectin-Ca2+”). [emphasis mine] “We let nature do the job for us,” explains Chiara Daraio, Professor of Mechanics and Materials.

The scientists were able to develop by far the most sensitive temperature sensor: an electronic module that changes its conductivity as a function of temperature. “No other sensor can respond to such small temperature fluctuations with such large changes in conductivity. Our sensor reacts with a responsivity at least 100 times higher compared to the best existing sensors,” says Raffaele Di Giacomo, a post-doc in Daraio’s group.

The scientists have provided an illustration of their concept using a tobacco leaf as the backdrop,

ETH scientists used cells form the tobacco plant to build the by far most sensitive temperature sensor. (Illustration: Daniele Flo / ETH Zurich)

ETH scientists used cells form the tobacco plant to build the by far most sensitive temperature sensor. (Illustration: Daniele Flo / ETH Zurich)

A March 31, 2015 ETH Zurich press release, which despite the release date originated the news item, describes the concept in more detail,

It has been known for decades that plants have the extraordinary ability to register extremely fine temperature differences and respond to them through changes in the conductivity of their cells. In doing so, plants are better than any man-made sensor so far.

Di Giacomo experimented with tobacco cells in a cell culture. “We asked ourselves how we might transfer these cells into a lifeless, dry material in such a way that their temperature-sensitive properties are preserved,” he recounts. The scientists achieved their objective by growing the cells in a medium containing tiny tubes of carbon. These electrically conductive carbon nanotubes formed a network between the tobacco cells and were also able to penetrate the cell walls. When Di Giacomo dried the nanotube-cultivated cells, he discovered a woody, firm material that he calls ‘cyberwood’. In contrast to wood, this material is electrically conductive thanks to the nanotubes, and interestingly the conductivity is temperature-dependent and extremely sensitive, just like in living tobacco cells.

The scientists considered  the new material’s (cyberwood) properties and possible future applications (from the news release),

As demonstrated by experiments, the cyberwood sensor can identify warm bodies even at distance; for example, a hand approaching the sensor from a distance of a few dozen centimetres. The sensor’s conductivity depends directly on the hand’s distance from the sensor.

According to the scientists, cyberwood could be used in a wide range of applications; for instance, in the development of a ‘touchless touchscreen’ that reacts to gestures, with the gestures recorded by multiple sensors. Equally conceivable might be heat-sensitive cameras or night-vision devices.

The Swiss researchers along with a collaborator at the University of Salerno (Italy) did further research into the origins of the material’s behaviour (from the news release),

The ETH scientists, together with a collaborator at the University of Salerno, Italy, not only subjected their new material’s properties to a detailed examination, they also analysed the origins of their extraordinary behaviour. They discovered that pectins and charged atoms (ions) play a key role in the temperature sensitivity of both living plant cells and the dry cyberwood. Pectins are sugar molecules found in plant cell walls that can be cross-linked, depending on temperature, to form a gel. Calcium and magnesium ions are both present in this gel. “As the temperature rises, the links of the pectin break apart, the gel becomes softer, and the ions can move about more freely,” explains Di Giacomo. As a result, the material conducts electricity better when temperature increases.

The news release goes on to mention a patent and future plans,

The scientists submitted a patent application for their sensor. In ongoing work, they are now further developing it such that it functions without plant cells, essentially with only pectin and ions. Their goal is to create a flexible, transparent and even biocompatible sensor with the same ultrahigh temperature sensitivity. Such a sensor could be moulded into arbitrary shapes and produced at extremely low cost. This will open the door to new applications for thermal sensors in biomedical devices, consumer products and low cost thermal cameras.

Here’s a link to and a citation for the paper,

Plant nanobionic materials with a giant temperature response mediated by pectin-Ca2+ by Raffaele Di Giacomo, Chiara Daraio, and Bruno Maresca. Published online before print March 30, 2015, doi: 10.1073/pnas.1421020112 PNAS March 30, 2015

This paper is behind a paywall.

Institute for Electrical and Electronics Engineers’ (IEEE) Nano 2015 conference call for papers

The institute for Electrical and Electronics Engineers is holding its Nano 2015 conference in Rome, Italy from July 27 – 30, 2015. This is the second call for papers (I missed the first call),

We invite you to submit papers, proposals for tutorials, workshops to the International IEEE Conference on Nanotechnology which will be held in Rome, July 27-30, 2015. (See www.ieeenano15.org). The dead-line for abstract submission is 15th March 2015.

This conference is the 15th edition of the flagship annual event of the IEEE Nanotechnology Council. IEEE NANO 2015 will provide an international forum for the exchange of technical information in a wide variety of branches of Nanotechnology and Nanoscience, through feature tutorials, workshops, track sessions and special sessions; plenary and invited talks from the most renowned scientists and engineers; exhibition of software, hardware, equipment, materials, services and literature. With its fantastic setting in the centre of the Eternal City, at a walking distance from Colosseum and from the most exciting locations of ancient Rome, IEEE NANO 2015 will provide a perfect forum for inspiration, interactions and exchange of ideas.

All accepted papers will be published by IEEE Press, included in IEEE Xplore and Indexed by EI. Selected conference papers will be considered for publication on IEEE Transactions on Nanotechnology.

Important Dates

March 15, 2015:       Tutorial/Workshop Proposal
March 15, 2015:        Abstract Submission
April 15, 2015:           Acceptance Notification

May 15, 2015:            Full Paper Submission
June 1, 2015:              End of early Registration

Topics for contributing papers include but are not limited to:

Nanosensors, Actuators
Smart systems
Graphene-Based Materials
Nano-energy, Energy Harvesting
Nanobiology, Nanobiotechnology
Nano-optics, Nano-photonics
Nano-electromagnetics, NanoEMC
Nanofabrication, Nanoassemblies
Nanorobotics, Nanomanipulation
Multiscale Modeling and Simulation

PLENARY SPEAKERS (See www.ieeenano15.org/program/plenary-speakers)
George Bourianoff, Intel (USA)
Michael Grätzel, EPFL (Switzerland)
Roberto Cingolani, IIT (Italy)
Rodney Ruoff, NIST (Korea)
Takao Someya, Tokyo Univ. (Japan)
Theresa Mayer, Pennsylvania State Univ. (USA)
Zhong Lin Wang, Georgia Tech (USA)

1) Graphene
2) Nanoelectromagnetics and Nano-EMC
3) Nanometrology and device characterization
4) Nanotechnology for microwave and THz
5) Memristor
Part 1: Resistive switching: from fundamentals to production
Part 2: Memristive nanodevices and nanocircuits
6) Nanophononics
7) Drug Toxicity Mitigation. Nanotechnology-Enabled Strategies
8) Conformable Electronics and E-Skin
9) Organic Neurooptoelectronics

There are more details about the call in this PDF. Good luck!

Water purification, Italy, Romania, and graphene

I’m hauling some of the material out of my backlog for publication as I clear the decks for 2015 including this Dec. 17, 2014 news item on Nanowerk about water remediation,

Graphene Plus materials have an amazing capacity for adsorbing organic pollutants such as hydrocarbons from water, soils and air. Directa Plus has already certified the removal capacity of Graphene Plus for floating oils in water and has obtained the approval of the Italian Environmental Ministry for the use these products in oil spills clean-up activities. Graphene Plus is also object of GEnIuS (Graphene Eco Innovative Sorbent), a Directa Plus’ project co-founded by European Union within the Eco-Innovation initiative. The project aims to launch into real markets an innovative solution for water treatment based on graphene.

A Dec. 17, 2014 Directa Plus press release, which originated the news item, describes how a Romanian company has tested the effectiveness of Graphene Plus for water remediation,

Directa Plus has found in SetCar – a Romanian company with fourteen years of activity in decontamination and disposal of hazardous waste – an ideal partner for testing environmental applications of Graphene Plus materials, especially in environmental remediation.

Since summer 2014, SetCar has tested on laboratory scale Graphene Plus materials as adsorbents for different type of organic pollutants. The most impressive laboratory results have been obtained with Grafysorber™ and have encouraged pilot test in hydrocarbons removal from contaminated waters.

The first treatment project started on 14th October, 2014, inside a Romanian former refinery site, containing a basin with about 16 500 m3 of water contaminated with petroleum hydrocarbons. The initial hydrocarbons concentration in water was about 56 ppm (3 drops of oil inside 1 litre of water), which means more than 1 tonne of pollutants that must be removed. The hydrocarbons maximum concentration necessary for the discharge of treated water into superficial aquatic ecosystems is 5 ppm.

“5 g/m3 of Grafysorber™ were able to bring the hydrocarbons concentration down to 1 ppm or lower and in only 10 minutes of contacts with the contaminated water! – says Eng. Covaci Melchisedec, Technical Manager of SetCar SA – We worked with a flow rate of 16 m3/h (daily flow rate of 360 -390 m3) in 2 consecutive batches of 4 m3. The total quantity of Grafysorber™ used in this project, which is now concluded, was 80 kg. In next projects, we have planned to implement the productivity of our treatment plant for low concentration hydrocarbons removal till 50 m3/h.”

Giulio Cesareo, President and CEO of Directa Plus shows his satisfaction for this collaboration and says “Our company needs partners such as SetCar SA. Setcar SA has a solid experience in decontamination field but, at the same time, a consolidate team of more than 50 engineers. Thanks to SetCar pilot test we obtained the real evidence that Grafysorber™ is an effective solution for decontamination of water containing hydrocarbons at low concentration”.

The Commercial Director of SetCar SA, Sandu Balan adds “We want to explore Graphene Plus potentiality in removing different type of pollutants from real contaminated water, soils and air and use it in other international projects of decontamination”.

Directa Plus, founded in 2005 and with headquarters in the ComoNext Science and Technology Park in Lomazzo (CO), is a technology company pursuing the development and marketing innovative manufacturing processes for the production of a new generation of nanomaterials targeting existing global markets. On June 23rd, 2014, Directa Plus opened its “Graphene Factory”, a new industrial centre distinguished for being the largest production plant in Europe of pristine graphene nanoplatelets, based on a patented and granted technology and designed according to a modular, replicable and exportable logic. The first module has 30-tonnes per year production capacity. To date, Directa Plus holds 26 granted patents and 19 patents pending. …

Setcar S.A. Established in 1994 as a joint stock company with entirely Rumanian private capital, the company is been developing since 2000 the range of services aimed to solve the environment issues, having as permanent concern the supply of a complete range of services, from chemical analyses for waste identification or, by creating new technologies, up to hazardous waste disposal or bringing the contaminated site to initial condition. …

You can find out more about Directa Plus here and about SetCar here (you will need your Romanian language skills as I cannot find an English language version of the site).

White beetles and complex photonic nanostructures

At least one species of white beetles which have excited scientists with their complex nanostructures are native to Southeast Asia according to an Aug. 15, 2014 news item on Nanowerk,

The physical properties of the ultra-white scales on certain species of beetle could be used to make whiter paper, plastics and paints, while using far less material than is used in current manufacturing methods.

The Cyphochilus beetle, which is native to South-East Asia, is whiter than paper, thanks to ultra-thin scales which cover its body. A new investigation of the optical properties of these scales has shown that they are able to scatter light more efficiently than any other biological tissue known, which is how they are able to achieve such a bright whiteness.

An Aug. 15, 2014 University of Cambridge press release (also on EurekAlert), which originated the news item, describes the properties needed to create the optical conditions necessary for the colour white to be seen,

Animals produce colours for several purposes, from camouflage to communication, to mating and thermoregulation. Bright colours are usually produced using pigments, which absorb certain wavelengths of light and reflect others, which our eyes then perceive as colour.

To appear as white, however, a tissue needs to reflect all wavelengths of light with the same efficiency. The ultra-white Cyphochilus and L. Stigma beetles produce this colouration by exploiting the geometry of a dense complex network of chitin – a molecule similar in structure to cellulose, which is found throughout nature, including in the shells of molluscs, the exoskeletons of insects and the cell walls of fungi. The chitin filaments are just a few billionths of a metre thick, and on their own are not particularly good at reflecting light.

The research, a collaboration between the University of Cambridge and the European Laboratory for non-Linear Spectroscopy in Italy has shown that the beetles have optimised their internal structure in order to produce maximum white with minimum material, like a painter who needs to whiten a wall with a very small quantity of paint. This efficiency is particularly important for insects that fly, as it makes them lighter.

Here’s what the Cyphochilus beetle looks like,

Cyphochilus beetle Credit: Lorenzo Cortese and Silvia Vignolini

Cyphochilus beetle Credit: Lorenzo Cortese and Silvia Vignolini Courtesy University of Cambridge

The press release goes on to describe the beetle’s optical properties in greater detail,

Over millions of years of evolution the beetles have developed a compressed network of chitin filaments. This network is directionally-dependent, or anisotropic, which allows high intensities of reflected light for all colours at the same time, resulting in a very intense white with very little material.

“Current technology is not able to produce a coating as white as these beetles can in such a thin layer,” said Dr Silvia Vignolini of the University’s Cavendish Laboratory, who led the research. “In order to survive, these beetles need to optimise their optical response but this comes with the strong constraint of using as little material as possible in order to save energy and to keep the scales light enough in order to fly. Curiously, these beetles succeed in this task using chitin, which has a relatively low refractive index.”

The secret lies in the beetles’ nanostructures,

Exactly how this could be possible remained unclear up to now. The researchers studied how light propagates in the white scales, quantitatively measuring their scattering strength for the first time and demonstrating that they scatter light more efficiently than any other low-refractive-index material yet known.

“These scales have a structure that is truly complex since it gives rise to something that is more than the sum of its parts,” said co-author Dr Matteo Burresi of the Italian National Institute of Optics in Florence. “Our simulations show that a randomly packed collection of its constituent elements by itself is not sufficient to achieve the degree of brightness that we observe.”

Here’s a link to and a citation for the paper,

Bright-White Beetle Scales Optimise Multiple Scattering of Light by Matteo Burresi, Lorenzo Cortese, Lorenzo Pattelli, Mathias Kolle, Peter Vukusic, Diederik S. Wiersma, Ullrich Steiner, & Silvia Vignolini.  Scientific Reports 4, Article number: 6075 doi:10.1038/srep06075 Published 15 August 2014

This paper is open access.

Cookies, ants, and a citizen science project plus a call for proposals for a 2015 Citizen Science Conference

My first citizen science item concerns summertime when the ants are out and about, oftentimes as uninvited participants to a picnic. Scientists at North Carolina State University (NCSU) and the University of Florida (UF) have decided to take advantage of this summer phenomenon as per a July 7, 2014 news item on ScienceDaily,

Scientists from North Carolina State University and the University of Florida have combined cookies, citizen science and robust research methods to track the diversity of ant species across the United States, and are now collaborating with international partners to get a global perspective on how ants are moving and surviving in the modern world.

“We think our School of Ants project serves as a good model for how citizen science can be used to collect more data, more quickly, from more places than a research team could do otherwise,” says Dr. Andrea Lucky, a researcher at the University of Florida who started work on the School of Ants while a postdoctoral researcher at NC State and now heads the project. Lucky is co-lead author of a paper describing the work and its early findings. “And our protocols help ensure that the data we are collecting are high quality.”

A July 7, 2014 NCSU news release (also on EurekAlert), which originated the news item, describes the various objectives for the project,

The School of Ants project was developed at NC State to help researchers get a handle on the diversity of ant species across the United States, with a particular focus on Chicago, Raleigh and New York City. In short, to discover which ant species are living where.

“But we also wanted to launch a citizen science project that both increased the public’s ecological literacy and addressed criticisms that public involvement made citizen science data unreliable,” says Dr. Amy Savage , a postdoctoral biological sciences researcher at NC State and the other co-lead author of the paper.

The research protocol, process, and outcomes are then described (from the news release),

The researchers developed a simple protocol involving Pecan Sandies cookies and sealable plastic bags, detailing precisely how the public should collect and label ant samples before shipping them to NC State or UF. [emphasis mine] This process was designed to engage the public in the aspect of the research that was easiest for non-scientists to enjoy and participate in, while also limiting the chances that the public could make mistakes that would skew the findings.

Once the samples arrive at NC State or UF, they are sorted, identified by a team of national experts and entered into a database. That information is then made publicly available in a user-friendly format on the project’s schoolofants.org site, allowing study participants to track the survey.

“This information is helping us tackle a variety of ecological and evolutionary questions, such as how ants may be evolving in urban environments, and how invasive species are spreading in the U.S.,” Savage says.

More than 1,000 participants, with samples from all 50 states, have taken part in the project since its 2011 launch – and there have already been some surprising findings.

For example, the researchers learned that a venomous invasive species, the Asian needle ant (Pachycondyla chinensis), had spread thousands of miles farther than anyone expected. Researchers knew the species had established itself in the Southeast, but study participants sent in Asian needle ant samples from as far afield as Wisconsin and Washington state.

To build on the School of Ants model, the researchers have launched collaborations with counterparts in Italy and Australia.

“We’re optimistic that this project will give us a broader view of ant diversity and how these species intersect with us, where we live and work around the world,” Lucky says.

The researchers are also working with teachers to incorporate the project into K-12 instruction modules that incorporate key elements of common core education standards. One early teacher collaboration has led to a research paper co-written by 4th and 5th graders.

“We also collaborated with a science writer to produce a free series of iBooks featuring natural history stories about the most common ants that our citizen science partners are collecting in their backyards and sidewalks,” Savage says.

“One of our big goals now is to move from collecting data and finding patterns to identifying ways that we can work with the public to figure out what is driving those patterns,” says Dr. Rob Dunn, an associate professor of biological sciences at NC State and co-author of the paper.

Not being familiar with Pecan Sandies cookies I went searching on the internet and found many recipes including this one from Martha Stewart’s website,

 Pecan Sandies

prep: 15 mins
total time: 30 mins
yield: Makes 18


1/2 cup (1 stick) unsalted butter, room temperature
1/2 cup packed light-brown sugar
1 1/2 teaspoons pure vanilla extract
1/4 teaspoon salt
1 cup all-purpose flour (spooned and leveled)
1 cup pecans, coarsely chopped

Cook’s Note
For best results, line cookie sheets with parchment prior to baking.

Step 1

Preheat oven to 350 degrees, with racks in upper and lower thirds. In a large bowl, using an electric mixer, beat butter and sugar until light and fluffy; beat in vanilla and salt. With mixer on low, gradually add flour, beating just until combined. Fold in pecans.

Step 2

Roll dough into 1 1/2-inch balls, and place on two baking sheets, 2 inches apart. With the dampened bottom of a glass, lightly flatten each ball.

Step 3

Bake until cookies are golden brown, 15 to 17 minutes, rotating sheets halfway through. Transfer to wire racks, and let cool.

This is what they look like (also from the Martha Stewart website),

[downloaded from http://www.marthastewart.com/342386/pecan-sandies]

[downloaded from http://www.marthastewart.com/342386/pecan-sandies]

I also checked out the School of Ants project website and found this,

The School of Ants project is a citizen-scientist driven study of the ants that live in urban areas, particularly around homes and schools. Participation is open to anyone interested!
Learn More!

Anyone can participate! Learn how to create your own sampling kit, sample your backyard or schoolyard, and get our collection back to us so that we can ID the ants and add your species list to the big School of Ants map. Together we’ll map ant diversity and species ranges across North America! Click here to get started!

There is at least one question you might want to ask before running off to collect ants, the researchers specify Keebler Pecan Sandies cookies are to be used as bait. I’m not sure how available those specific cookies and brand are in Canada, Mexico, Italy, or Australia. You may want to check with the organizers as to what alternatives might be acceptable. From the Participate webpage on the School of Ants website,

SAMPLING ANTS for the School of Ants involves placing cookie baits outdoors in green spaces (lawns, gardens, woods) and paved places (asphalt, concrete, cobblestone) for one hour on a warm day. We want to know what ants discover the baits in your neighborhood!(ALLERGY WARNING!: this activity uses Keebler Pecan Sandies cookies, which contain pecans, wheat, egg and whey).

Here’s a link to and a citation for the paper,

Ecologists, educators, and writers collaborate with the public to assess backyard diversity in The School of Ants Project [PDF] by Andrea Lucky, Amy M. Savage, Lauren M. Nichols, Leonora Shell, Robert R. Dunn, Cristina Castracani, Donato A. Grasso, and Alessandra Mori. Ecosphere 5(7):78. http://dx.doi.org/10.1890/ES13-00364.1 Published: online July 7, 2014,

Ecosphere is an open access journal. The PDF is 23 pp.

For my second citizen science item, I have a call for proposals for the Citizen Science 2015 Conference (CS2015), February 11 & 12, 2015 in San Jose, California (prior to the 2015 AAAS [American Association for the Advancement of Science] annual meeting February 12 -16, 2015 also in San Jose). Here’s more about the Citizen Science conference from the Overview page,

Anyone involved in citizen science is invited to attend this conference. Attendees will include citizen science participants, researchers, project leaders, educators, technology specialists, evaluators, and others – representing many disciplines including astronomy, molecular biology, human and environmental health, psychology, linguistics, environmental justice, biodiversity, conservation biology, public health, genetics, engineering, cyber technology, gaming, and more – at any level of expertise. There will be opportunities throughout the conference to make connections, share insights, and help move this field forward.

We have identified six main themes for this year’s conference:

  1. Tackling Grand Challenges and Everyday Problems with Citizen Science
  2. Broadening Engagement to Foster Diversity and Inclusion
  3. Making Education and Lifelong Learning Connections (K-12, university, informal)
  4. Digital Opportunities and Challenges in Citizen Science
  5. Research on and Evaluation of the Citizen Science Experience
  6. Best Practices for Designing, Implementing, and Managing Citizen Science Projects and Programs

Here are important dates for the conference (from a June 30, 2014 email announcement),

September 15, 2014          CS2015 Deadline to submit proposals* (talks, posters, etc)
October 6, 2014                 CS2015 Proposal selection notices sent out
November 10, 2014           CS2015 Early-bird registration discount ends
February 11 & 12, 2015     CS2015 Conference

Here’s more detail, from the Presentation Styles webpage,

… Several formats are available to choose from: three styles of oral presentations; symposia/panel discussions; and posters.

Audio-visual equipment will be provided as needed for all session types except posters.

Oral Presentations
Talks allow speakers to present their work in 12 minutes, with 3 additional minutes for audience questions. Talks with similar themes will be grouped together into sessions.

Speed Talks, as the name suggests, challenge each presenter to cover his or her topic in 5 minutes or less. Following a series of speed presentations, there will be time for audience members to gather with presenters for discussion.

Story Presentations (15 minutes) emphasize sharing valuable lessons through storytelling. We especially encourage telling stories of “what didn’t work and why” and strategies for addressing challenges and unintended consequences.

Symposium Sessions or Panel Discussions (1 to 2 hours)
Every symposium or panel has one convener (most likely the person submitting this proposal); that person is responsible for organizing the session and will act as the session’s contact person with conference organizers. Additionally, that person will moderate/guide the session. Symposia/Panels may be 1-to-2 hours in length, depending on the number of proposed talks, and must include at least 15 minutes for questions and discussion with the audience.

The proposal must (1) describe the symposium or panel’s objective, (2) how it will contribute to the overall theme of the conference, and (3) include a list of proposed speakers (and, in the case of a symposium, each speaker’s topic).

Posters are designed to visually display information and engage fellow attendees in an informal way. There will be two Poster Sessions—one each day—inviting attendees to discuss posters with authors. Posters will also be on display outside of formal poster-session times. All accepted posters will be given a display space measuring 4 x 4 feet (1.2 X 1.2 meters) in the Poster Hall (no additional audio-visual aids are permitted).

You can access a link to submit your proposal here.

CS2015 is being called a pre-conference to the AAAS meeting as per the Prepare for the Conference page,

Registration details, including the conference registration fee, are not yet finalized. We are seeking funding to help support the conference and keep it affordable to all. Check back for updates, or join the CSA to receive periodic updates.

Attend Two Great Conferences
CS2015 is a pre-conference of the Annual Meeting of the American Association for the Advancement of Science (AAAS), which immediately follows our meeting at the San Jose Convention Center. The AAAS theme for 2015 is “Innovations, Information, and Imaging.” Once you have completed your CS2015 registration, you will receive instructions on how to register for the AAAS Annual Meeting (February 12-16, 2015) at the discounted rate of $235. AAAS registration will open in August 2014.

Good luck with your proposal and with your ant-captures!

Gold on the brain, a possible nanoparticle delivery system for drugs

A July 21, 2014 news item on Nanowerk describes special gold nanoparticles that could make drug delivery to cells easier,

A special class of tiny gold particles can easily slip through cell membranes, making them good candidates to deliver drugs directly to target cells.

A new study from MIT materials scientists reveals that these nanoparticles enter cells by taking advantage of a route normally used in vesicle-vesicle fusion, a crucial process that allows signal transmission between neurons.

A July 21, 2014 MIT (Massachusetts Institute of Technology) news release (also on EurekAlert), which originated the news item, provides more details,

The findings suggest possible strategies for designing nanoparticles — made from gold or other materials — that could get into cells even more easily.

“We’ve identified a type of mechanism that might be more prevalent than is currently known,” says Reid Van Lehn, an MIT graduate student in materials science and engineering and one of the paper’s lead authors. “By identifying this pathway for the first time it also suggests not only how to engineer this particular class of nanoparticles, but that this pathway might be active in other systems as well.”

The paper’s other lead author is Maria Ricci of École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland. The research team, led by Alfredo Alexander-Katz, an associate professor of materials science and engineering, and Francesco Stellacci from EPFL, also included scientists from the Carlos Besta Institute of Neurology in Italy and Durham University in the United Kingdom.

Most nanoparticles enter cells through endocytosis, a process that traps the particles in intracellular compartments, which can damage the cell membrane and cause cell contents to leak out. However, in 2008, Stellacci, who was then at MIT, and Darrell Irvine, a professor of materials science and engineering and of biological engineering, found that a special class of gold nanoparticles coated with a mix of molecules could enter cells without any disruption.

“Why this was happening, or how this was happening, was a complete mystery,” Van Lehn says.

Last year, Alexander-Katz, Van Lehn, Stellacci, and others discovered that the particles were somehow fusing with cell membranes and being absorbed into the cells. In their new study, they created detailed atomistic simulations to model how this happens, and performed experiments that confirmed the model’s predictions.

Gold nanoparticles used for drug delivery are usually coated with a thin layer of molecules that help tune their chemical properties. Some of these molecules, or ligands, are negatively charged and hydrophilic, while the rest are hydrophobic. The researchers found that the particles’ ability to enter cells depends on interactions between hydrophobic ligands and lipids found in the cell membrane.

Cell membranes consist of a double layer of phospholipid molecules, which have hydrophobic lipid tails and hydrophilic heads. The lipid tails face in toward each other, while the hydrophilic heads face out.

In their computer simulations, the researchers first created what they call a “perfect bilayer,” in which all of the lipid tails stay in place within the membrane. Under these conditions, the researchers found that the gold nanoparticles could not fuse with the cell membrane.

However, if the model membrane includes a “defect” — an opening through which lipid tails can slip out — nanoparticles begin to enter the membrane. When these lipid protrusions occur, the lipids and particles cling to each other because they are both hydrophobic, and the particles are engulfed by the membrane without damaging it.

In real cell membranes, these protrusions occur randomly, especially near sites where proteins are embedded in the membrane. They also occur more often in curved sections of membrane, because it’s harder for the hydrophilic heads to fully cover a curved area than a flat one, leaving gaps for the lipid tails to protrude.

“It’s a packing problem,” Alexander-Katz says. “There’s open space where tails can come out, and there will be water contact. It just makes it 100 times more probable to have one of these protrusions come out in highly curved regions of the membrane.”

This phenomenon appears to mimic a process that occurs naturally in cells — the fusion of vesicles with the cell membrane. Vesicles are small spheres of membrane-like material that carry cargo such as neurotransmitters or hormones.

The similarity between absorption of vesicles and nanoparticle entry suggests that cells where a lot of vesicle fusion naturally occurs could be good targets for drug delivery by gold nanoparticles. The researchers plan to further analyze how the composition of the membranes and the proteins embedded in them influence the absorption process in different cell types. “We want to really understand all the constraints and determine how we can best design nanoparticles to target particular cell types, or regions of a cell,” Van Lehn says.

Here’s a link to and a citation for the paper,

Lipid tail protrusions mediate the insertion of nanoparticles into model cell membranes by Reid C. Van Lehn, Maria Ricci, Paulo H.J. Silva, Patrizia Andreozzi, Javier Reguera, Kislon Voïtchovsky, Francesco Stellacci, & Alfredo Alexander-Katz. Nature Communications 5, Article number: 4482 doi:10.1038/ncomms5482 Published 21 July 2014

This article is behind a paywall but there is a free preview available via ReadCube Access.

I last featured this multi-country team’s work on gold nanoparticles in an Aug. 23, 2013 posting.

Memristors, memcapacitors, and meminductors for faster computers

While some call memristors a fourth fundamental component alongside resistors, capacitors, and inductors (as mentioned in my June 26, 2014 posting which featured an update of sorts on memristors [scroll down about 80% of the way]), others view memristors as members of an emerging periodic table of circuit elements (as per my April 7, 2010 posting).

It seems scientists, Fabio Traversa, and his colleagues fall into the ‘periodic table of circuit elements’ camp. From Traversa’s  June 27, 2014 posting on nanotechweb.org,

Memristors, memcapacitors and meminductors may retain information even without a power source. Several applications of these devices have already been proposed, yet arguably one of the most appealing is ‘memcomputing’ – a brain-inspired computing paradigm utilizing the ability of emergent nanoscale devices to store and process information on the same physical platform.

A multidisciplinary team of researchers from the Autonomous University of Barcelona in Spain, the University of California San Diego and the University of South Carolina in the US, and the Polytechnic of Turin in Italy, suggest a realization of “memcomputing” based on nanoscale memcapacitors. They propose and analyse a major advancement in using memcapacitive systems (capacitors with memory), as central elements for Very Large Scale Integration (VLSI) circuits capable of storing and processing information on the same physical platform. They name this architecture Dynamic Computing Random Access Memory (DCRAM).

Using the standard configuration of a Dynamic Random Access Memory (DRAM) where the capacitors have been substituted with solid-state based memcapacitive systems, they show the possibility of performing WRITE, READ and polymorphic logic operations by only applying modulated voltage pulses to the memory cells. Being based on memcapacitors, the DCRAM expands very little energy per operation. It is a realistic memcomputing machine that overcomes the von Neumann bottleneck and clearly exhibits intrinsic parallelism and functional polymorphism.

Here’s a link to and a citation for the paper,

Dynamic computing random access memory by F L Traversa, F Bonani, Y V Pershin, and M Di Ventra. Nanotechnology Volume 25 Number 28  doi:10.1088/0957-4484/25/28/285201 Published 27 June 2014

This paper is behind a paywall.

Italians and Polish collaborate on nanoscale study of vanishing Da Vinci self-portrait

In addition to a new nondamaging technique to examine paintings (my June 2, 2014 post: Damage-free art authentication and spatially offset Raman spectroscopy [SORS]), there’s a new report in a June 3, 2014 news item on ScienceDaily about a nondamaging technique to examine paper such as the paper on which holds a Da Vinci self-portrait,

One of Leonardo da Vinci’s masterpieces, drawn in red chalk on paper during the early 1500s and widely believed to be a self-portrait, is in extremely poor condition. Centuries of exposure to humid storage conditions or a closed environment has led to widespread and localized yellowing and browning of the paper, which is reducing the contrast between the colors of chalk and paper and substantially diminishing the visibility of the drawing.

A group of researchers from Italy and Poland with expertise in paper degradation mechanisms was tasked with determining whether the degradation process has now slowed with appropriate conservation conditions — or if the aging process is continuing at an unacceptable rate.

Caption: This is Leonardo da Vinci's self-portrait as acquired during diagnostic studies carried out at the Central Institute for the Restoration of Archival and Library Heritage in Rome, Italy. Credit: M. C. Misiti/Central Institute for the Restoration of Archival and Library Heritage, Rome

Caption: This is Leonardo da Vinci’s self-portrait as acquired during diagnostic studies carried out at the Central Institute for the Restoration of Archival and Library Heritage in Rome, Italy.
Credit: M. C. Misiti/Central Institute for the Restoration of Archival and Library Heritage, Rome

The June 3, 2014 American Institute of Physics news release on EurekAlert provides more detail about the work,

… the team developed an approach to nondestructively identify and quantify the concentration of light-absorbing molecules known as chromophores in ancient paper, the culprit behind the “yellowing” of the cellulose within ancient documents and works of art.

“During the centuries, the combined actions of light, heat, moisture, metallic and acidic impurities, and pollutant gases modify the white color of ancient paper’s main component: cellulose,” explained Joanna Łojewska, a professor in the Department of Chemistry at Jagiellonian University in Krakow, Poland. “This phenomenon is known as ‘yellowing,’ which causes severe damage and negatively affects the aesthetic enjoyment of ancient art works on paper.”

Chromophores are the key to understanding the visual degradation process because they are among the chemical products developed by oxidation during aging and are, ultimately, behind the “yellowing” within cellulose. Yellowing occurs when “chromophores within cellulose absorb the violet and blue range of visible light and largely scatter the yellow and red portions — resulting in the characteristic yellow-brown hue,” said Olivia Pulci, a professor in the Physics Department at the University of Rome Tor Vergata.

To determine the degradation rate of Leonardo’s self-portrait, the team created a nondestructive approach that centers on identifying and quantifying the concentration of chromophores within paper. It involves using a reflectance spectroscopy setup to obtain optical reflectance spectra of paper samples in the near-infrared, visible, and near-ultraviolet wavelength ranges.

Once reflectance data is gathered, the optical absorption spectrum of cellulose fibers that form the sheet of paper can be calculated using special spectroscopic data analysis.

Then, computational simulations based on quantum mechanics — in particular, Time-Dependent Density Functional Theory, which plays a key role in studying optical properties in theoretical condensed matter physics — are tapped to calculate the optical absorption spectrum of chromophores in cellulose.

“Using our approach, we were able to evaluate the state of degradation of Leonardo da Vinci’s self-portrait and other paper specimens from ancient books dating from the 15th century,” said Adriano Mosca Conte, a researcher at the University of Rome Tor Vergata. “By comparing the results of ancient papers with those of artificially aged samples, we gained significant insights into the environmental conditions in which Leonardo da Vinci’s self-portrait was stored during its lifetime.”

Their work revealed that the type of chromophores present in Leonardo’s self portrait are “similar to those found in ancient and modern paper samples aged in extremely humid conditions or within a closed environment, which agrees with its documented history,” said Mauro Missori, a researcher at the Institute for Complex Systems, CNR, in Rome, Italy.

One of the most significant implications of their work is that the state of degradation of ancient paper can be measured and quantified by evaluation of the concentrations of chromophores in cellulose fibers. “The periodic repetition of our approach is fundamental to establishing the formation rate of chromophores within the self-portrait. Now our approach can serve as a precious tool to preserve and save not only this invaluable work of art, but others as well,” Conte noted.

Absolutely fascinating stuff to those of use who care about yellowing paper. (Having worked in an archives, I care deeply.) Here’s a link to and a citation for the study,

Visual degradation in Leonardo da Vinci’s iconic self-portrait: A nanoscale study by A. Mosca Conte, O. Pulci, M. C. Misiti, J. Lojewska, L. Teodonio1, C. Violante, and M. Missori. Appl. Phys. Lett. 104, 224101 (2014); http://dx.doi.org/10.1063/1.4879838

This is an open access study.

Damage-free art authentication and spatially offset Raman spectroscopy (SORS)

In a world where people will shell out millions of dollars for a single painting, art authentication of some kind is mandatory from a buyer’s perspective while sellers might be a little more reluctant. Reliance on experts who have an intimate familiarity with an artist’s body of work, personal and professional history, as well as, the historical period in which the work was created is the norm. Technological means are not necessarily as heavily employed as one might expect. Given that most technical analyses require damage of some kind, no matter how miniscule, some reluctance is understandable.

A May 29, 2014 news item on phys.org describes a new, damage-free, art conservation and restoration process (which could easily be used for authentication purposes),

UK scientists, working on an international project to conserve precious works of art, have found a new way to analyse paintings without having to remove even a tiny speck of the paint to inspect the layers below.

Using laser spectroscopy, a method that uses light to probe under the surface of an object, the international team has developed a new, non-invasive way to identify the chemical content of the paint layers present.

This new technique will reduce the risk of damage to precious paintings, often worth thousands or even millions of pounds, when conservation and restoration work is being carried out.

Using laser spectroscopy, a method that uses light to probe under the surface of an object, the international team has developed a new, non-invasive way to identify the chemical content of the paint layers present.

This new technique will reduce the risk of damage to precious paintings, often worth thousands or even millions of pounds, when conservation and restoration work is being carried out.

Read more at: http://phys.org/news/2014-05-lasers-analyse-priceless-art.html#jCp

As noted in a March 24, 2014 posting about using surface-enhanced Raman spectroscopy (SERS) to determine the characteristics of red pigment in a Renoir painting, restoration, authentication, and conservation are all linked once researchers start a technical examination,

This next item is about forgery detection. A March 5, 2014 news release on EurekAlert describes the latest developments,

Gallery owners, private collectors, conservators, museums and art dealers face many problems in protecting and evaluating their collections such as determining origin, authenticity and discovery of forgery, as well as conservation issues. Today these problems are more accurately addressed through the application of modern, non-destructive, “hi-tech” techniques.

Getting back to this new technique, a May 28, 2014 Science and Technology Facilities Council news release, which originated the news item, provides information about the various agencies involved with this work and offers some technical detail about the new technique,

The new approach is derived from a technique called Spatially Offset Raman Spectroscopy (SORS). It was originally developed by UK researchers at the Science and Technology Research Council’s (STFC) Central Laser Facility within the Research Complex at Harwell. Now they have joined forces with researchers from the Institute for the Conservation and Promotion of Cultural Heritage (ICVBC), part of Italy’s National Research Council (CNR) to adapt this technology to test paintings without having to destroy any part of them.

The SORS technique involves shining the laser light onto an opaque object. A small number of photons (light ‘particles’) will scatter back, changing colour according to the different paint components they represent, and allowing the scientists to analyse the chemical composition in depth.

Professor Pavel Matousek, from STFC’s Central Laser Facility, explained. “Building on our earlier SORS research, we’ve transformed the method to allow us to probe the painted layers for the first time,” he said. “We’ve called it Micro-SORS because we can analyse the layers at the micrometer scale, rather than the usual millimetre scale”.

For comparison of scale, a human hair is about 100 micrometers wide.

Dr Claudia Conti, a scientist at the ICVBC in Italy, said, “When I heard about the potential of SORS and how it could be applied, I realised the huge contribution this method of analysis could bring to the conservation of artworks.”

The research team tested the Micro-SORS method by collecting data from the light scattered across a surface of painted layers, artificially prepared to mimic a real painting. They isolated the light signals of the individual paint layers, enabling them to assess the chemical make-up of each layer.

The next step in the team’s research is to optimise the sensitivity and depth of penetration, and apply the technique to real artwork.

SORS has been used in other applications, from the news release,

The original SORS technique has already been applied to a number of problems, including non-invasive breast cancer diagnosis and bone disease diagnosis.The Science and Technology Facilities Council (STFC) has also launched a spin-out company, Cobalt Light Systems, which uses the SORS technology and has recently developed products for scanning liquids in unopened bottles for airport security, and in pharmaceutical quality control.

Here’s a link to and a citation for the research paper,

Subsurface Raman Analysis of Thin Painted Layers by Claudia Conti, Chiara Colombo, Marco Realini, Giuseppe Zerbi, and Pavel Matousek. Applied Spectroscopy, Volume 68, Number 6, June 2014, pp. 686-691(6) doi.org/10.1366/13-07376 Available online via Ingentaconnect

This article is open access.