Marine animals such as mussels（ムール貝）, oysters and barnacles フジツボ，エボシガイare naturally equipped with the means to adhere to rock, buoysブイ and other underwater structures and remain in place no matter how strong the waves and currents.
Synthetic wet adhesive materials, on the other hand, are a different story.
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Taking their cue from Mother Nature and the chemical composition of mussel foot proteins, the Alison Butler Lab at UC Santa Barbara decided to improve a small molecule called the siderophore cyclic trichrysobactin (CTC) that they had previously discovered. They modified the molecule and then tested its adhesive strength in aqueous environments. The result: a compound that rivals the staying power of mussel glue.
Their findings appear in the journal Science.
"There's real need in a lot of environments, including medicine, to be able to have glues that would work in an aqueous environment,"
said co-author Butler, a professor in UCSB's Department of Chemistry and Biochemistry.
"So now we have the basis of what we might try to develop from here."
Also part of the interdisciplinary effort were Jacob Israelachvili's Interfacial Sciences Lab in UCSB's Department of Chemical Engineering and J. Herbert Waite, a professor in the Department of Molecular, Cellular and Developmental Biology, whose own work focuses on wet adhesion.
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"We just happened to see a visual similarity between compounds in the siderophore CTC and in mussel foot proteins,"
Butler explained. Siderophores are molecules that bind and transport iron in microorganisms such as bacteria.
"We specifically looked at the synergy between the role of the amino acid lysine and catechol,"
she added.
"Both are present in mussel foot proteins and in CTC."
Mussel foot proteins contain similar amounts of lysine and the catechol dopa. Catechols are chemical compounds used in such biological functions as neurotransmission. However, certain proteins have adopted dopa for adhesive purposes.
From discussions with Waite, Butler realized that CTC contained not only lysine but also a compound similar to dopa. Further, CTC paired its catechol with lysine, just like mussel foot proteins do.
"We developed a better, more stable molecule than the actual CTC,"
Butler explained.
"Then we modified it to tease out the importance of the contributions from either lysine or the catechol."
Co-lead author Greg Maier, a graduate student in the Butler Lab, created six different compounds with varying amounts of lysine and catechol. The Israelachvili lab tested each compound for its surface and adhesion characteristics. Co-lead author Michael Rapp used a surface force apparatus developed in the lab to measure the interactions between mica surfaces in a saline solution.
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Only the two compounds containing a cationic amine, such as lysine, and catechol exhibited adhesive strength and a reduced intervening film thickness, which measures the amount two surfaces can be squeezed together. Compounds without catechol had greatly diminished adhesion levels but a similarly reduced film thickness.
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Without lysine, the compounds displayed neither characteristic.
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"Our tests showed that lysine was key, helping to remove salt ions from the surface to allow the glue to get to the underlying surface,"
Maier said.
"By looking at a different biosystem that has similar characteristics to some of the best-performing mussel glues, we were able to deduce that these two small components work together synergistically to create a favorable environment at surfaces to promote adherence,"
explained Rapp, a chemical engineering graduate student.
"Our results demonstrate that these two molecular groups not only prime the surface but also work collectively to build better adhesives that stick to surfaces."
"In a nutshell, our discovery is that you need lysine and you need the catechol,"
Butler concluded.
"There's a one-two punch: the lysine clears and primes the surface and the catechol comes down and hydrogen bonds to the mica surface. This is an unprecedented insight about what needs to happen during wet adhesion."
Magical. Captivating. Eccentric. These are just a few of the words that have been used to describe the imaginative work of Tim Walker. Like Gregroy Crewdson, Walker’s photographs are not just made, they are meticulously crafted. From the kernel of an idea in his mind to the building of the sets, he is there every step of the way taking care to make sure every detail is exactly where he wants it. His photographs are filled with beauty and a sense of whimsy. They seem to have the ability to entrance anyone who looks at them.
Born in England in 1970, Walker started taking photographs as a teenager. His real passion, however, began during a year of work experience before going to college. As part of his job, he found himself setting up the Cecil Beaton archive in the Condé Naste London library. Beaton soon became his inspiration. The photographs he found had a wonderful sense of play and fantasy, which Walker was highly attracted to. He went on to study photography and, after graduation, worked as a freelance photography assistant in London before moving to New York, where he was lucky enough to assist for Richard Avedon.
北斎の大波を意識してるのか？左奥に感じも見れる。
ideafixa.com/os-sonhos-editoriais-de-tim-walker/
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After only a year in New York, Walker moved back to England to care for his father who was suffering from leukemia. He spent a lot of that time shooting the things that surrounded him – his house, his family, the gardens, the sheep – it all became a sort of therapy for him, and, by 1996 he had a decent portfolio, which he took to the Vogue fashion director and soon had landed his first story.
That spread in Vogue launched his career in the fashion world, although he was told by many that he was not cut out for fashion. He agrees, saying,
“The point of fashion is that you take the epicure洗練された感覚の持ち主 you want. And fashion is the only photography that allows fantasy, and I’m a fantasist. I love beautiful clothes, but I don’t give a monkey’s what’s on the catwalks.”
He loves fashion for its imagination, for the freedom it gives him to tell a story, the story he wants to tell.
Walker draws on childhood memories, using an imagination that most of us have lost sight of as we have grown older.
Using scrapbooks and diaries, he draws out ideas for shoots before they become reality. He uses words and stories and sketches. His final images are a result of hours of work and collaborating with others to come up with the exact narrative he is looking for. He says,
ideafixa.com/os-sonhos-editoriais-de-tim-walker/
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“I often doodle いたずら書きをするthe picture I have in my head before I take it, to show people what I have in mind. Also, what is available to me is my imagination is limitless, while I can’t always get it in reality. I create these fantastical environments, which I then have to turn into a real photograph, so drawing them first helps.”
Much the way David Fincher approaches film, the environments Walker creates are akin to theatrical sets; intricately detailed and stunningly designed. Every inch of the frame is full of things to look at, from the giant eggs of a giant swan, to the nearly destroyed antique toy cars in a dust-filled room. One of his set designers, Shona Heath, says he would rather spend his photographer’s fee on sets and props than on a first-class air fare. His images evoke a sense of wonder and bring to mind a time and place where the world is carefree and happy. Walker likes to capture imaginary places and juxtapose them with something which has already been. They bring a sense of nostalgia, yes, but it is nostalgia for something that has never really existed. We have never actually been to the places in the images, but we feel as though we have, somewhere along the way, perhaps in our dreams.
Walker takes great care in picking out his models, believing that the relationship between the subject and the photographer is key. The model has to be the star of the photograph and has to embody the mood of the image. She has to be able to tell you the story without speaking a word. This is why Walker calls the best models “silent-movie actresses.” They have to be able to assume a character, become a persona, not just wear the clothes and pose. They have to immerse themselves in the world he has created.
Walker’s worlds are physical worlds; nothing is done digitally. All of the sets are done using real props, including things like a giant camera or an airplane in a bedroom. He has never been interested in the technical side of the camera, instead he uses it as “a window to something magical.” He compares it to cooking; being able to mix “a bit of a memory with a bit of something that you’ve seen on a film, together with something you’ve read in a book, and then a certain color. And you mix it up to create a new picture.”
After seeing such great success with his photographs, Walker has moved into short films. In 2010 he created The Lost Explorer, a film based on a short story by Patrick McGrath.He doesn’t have any illusions that he would be an expert just because he is a photographer, saying the disciplines “are so different.” He was, however, able to draw on the same imagination he uses so well in photography. The film is almost an extension of his still images, with the same surreal and fantasy-like sets.
There is a magic in photography that we often lose sight of pursuing the business of photography. Walker has not only kept that magic, but has embraced it. You can never be depressed looking at Walker’s photographs. He brings a sense of joy and playfulness that is so often missing in fashion photography. Fashion seems to take itself so seriously when it should be about fun, or at least parts of it should be. Walker brings that fun element back in and relishes it, something we could take a lesson from.
Image may be NSFW. Clik here to view.Image may be NSFW. Clik here to view.メラニンの合成を阻止し、メラニンに変える物質チロシナーゼ酵素の活性を抑制するというヒドロキノンやビタミンＣ、アルブチンやコウジ酸は美白剤に用いられるが、どの程度効果があるのか。
Image may be NSFW. Clik here to view.ヒドロキノンはビタミンCなどの美白成分とハイドロキノンが大きく異なる点Image may be NSFW. Clik here to view.は、既に出来てしまったシミに対して還元作用があるらしい。効果も１０～１００倍と。
ナッシュが主人公である。ゲーム理論の研究でノーベル経済学賞を受賞。１年飛び級しカーネギー工科大（現カーネギーメロン大）に入学。その後、プリンストン大に進学するが、入試の時に彼の指導教官が推薦書に書いたのは「This man is a genius」だけだったという。MIT教授（終身在職権付き）の職を得るも、統合失調症を発症。現在では回復しているが、彼の数奇な人生は本書を題材に映画化もされている。
One of the more successful English-speaking cybercrime forums, Darkode, was shut down today and 28 arrests of individuals linked to the site made across the world, the FBI and Europol confirmed this morning. Charges were filed in the US against 12 individuals. They included the apparent Darkode creator, 27-year-old Wisconsin resident Daniel Placek, an alleged admin, Swedish 27-year-old Johan Anders Gudmunds, and the accused creator of Facebook Spreader, malware designed to ensnare users of the social network into a massive botnet – a network of infected machines.
In one of the more surprising twists in the case, FORBES understands that one of those charged spent two summers interning as a mobile malware researcher at FireEye, a top US cybersecurity firm that’s received investment from the CIA’s In-Q-Tel, Goldman Sachs and Sequoia Capital, and has helped numerous companies recover from major breaches, including that of Sony Pictures last year. That same individual, 20-year-old Morgan Culbertson, has been accused of creating and selling the Dendroid malware, targeted at Google GOOGL +7.74%’s Android operating system. The US Attorney for Western District of Pennsylvania confirmed to FORBES the accused was the same Morgan Culbertson as the one listed on LinkedIn here. According to that page and court filings, he was selling his malware at the same time as working at FireEye.
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FireEye said in an emailed statement that it had suspended Culbertson from future work at the company. It’s believed he was interning in summer 2014 as well as 2013. One major concern for the company might be that Culbertson could have used confidential FireEye research to hone his malware. The firm has strong expertise in mobile security and has repeatedly highlighted weaknesses in Android, as well as Apple AAPL +5.67%’s iPhone. Culbertson would’ve learned a lot during his four months interning, whether for good or bad.
“He is accused of designing Dendroid, a coded malware intended to remotely access, control, and steal data from Google Android cellphones. The malware was allegedly offered for sale on Darkode,” the Department of Justice said today.
Dendroid was a particularly virulent strain of Android malware. When it was uncovered in March 2014, researchers were alarmed by its sophistication, as it was able to take pictures using the phone’s camera, record audio and video, listen in on calls and texts, and nab the victim’s photos or other data. The toolkit was being sold for $300 in Bitcoin, or other cryptocurrency, on cybercrime forums, whilst the source code was going for as much as $65,000. Its creator also offered a warranty promising the malware would go undetected by security software, according to an analysis by Lookout Mobile Security, whilst the malware itself was delivered over the Google Play store, masquerading as legitimate apps. It was a professional-looking service.
If Culbertson was Dendroid’s father, then he most likely enhanced his malware with some of the skills he learned at FireEye during his internships, the first of which lasted from May 2013 to August 2013, according to his LinkedIn page. “I improved Android malware detection by discovering new malicious malware families and using a multitude of different tools, automation techniques and decompiling analysis heuristics,” his description of his time at the firm reads. According to the United States Attorney filing related to Culbertson, he was disseminating Dendroid from January 2013 until August 2014.
He is currently a student at Carnegie Mellon University College of Engineering, according to his public online profiles, where he was awarded a slice of $2,500 in McGinnis Venture Competition winnings for an app he co-created. It sounded like a pretty neat app too: software for eye glasses that projected translations for any foreign language being spoken on to a screen in front of the user’s eye.
As for Darkode, it’s gone thanks to Operation Shrouded Horizon, which involved law enforcement action across 20 countries on at least 70 individuals involved in the site. The forum consisted of a small, but successful community of hackers, who traded malware and in some cases stolen data. Members of hacker crew Lizard Squad, which infamously took out the Playstation Network and Xbox Live last Christmas, were said to be users. It was an invite-only website and limited to those who had worth to other members, of which there were between 250 and 300. Those heading to the site will now see the seizure notice below.
学振の海外センターは、どこも手不足状態のなかで、職員の人たちが頑張ってくれていますが、今回のScience in Japanは第18回、初回は1996年開催という、ワシントンセンターの長年の頑張りによって続けられているものです。とくに今年は出席者が多く、下村センター長をはじめとする職員の苦労も実ったように感じます。
Thousands of honey bees in Australia are being fitted with tiny sensors as part of a world-first research program to monitor the insects and their environment using a technique known as 'swarm sensing'.
The research is being led by CSIRO and aims to improve honey bee pollination and productivity on farms as well as help understand the drivers of bee Colony Collapse Disorder (CCD), a condition decimating honey bee populations worldwide.
Up to 5000 sensors, measuring 2.5mm x 2.5 mm are being fitted to the backs of the bees in Hobart, Tasmania, before being released into the wild. It's the first time such large numbers of insects have been used for environmental monitoring.
"Honey bees play a vital role in the landscape through a free pollination service for agriculture, which various crops rely on to increase yields. A recent CSIRO study showed bee pollination in Faba beans can lead to a productivity increase of 17 per cent," CSIRO science leader Dr Paulo de Souza, who leads the swarm sensing project, said.
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"Around one third of the food we eat relies on pollination, but honey bee populations around the world are crashing because of the dreaded Varroa mite and Colony Collapse Disorder. Thankfully, Australia is currently free from both of those threats."
The research will also look at the impacts of agricultural pesticides on honey bees by monitoring insects that feed at sites with trace amounts of commonly used chemicals.
"Using this technology, we aim to understand the bee’s relationship with its environment. This should help us understand optimal productivity conditions as well as further our knowledge of the cause of colony collapse disorder,"
Dr de Souza said.
The sensors are tiny Radio Frequency Identification sensors that work in a similar way to a vehicle's e-tag, recording when the insect passes a particular checkpoint. The information is then sent remotely to a central location where researchers can use the signals from the 5000 sensors to build a comprehensive three dimensional model and visualise how these insects move through the landscape.
"Bees are social insects that return to the same point and operate on a very predictable schedule. Any change in their behaviour indicates a change in their environment. If we can model their movements, we'll be able to recognise very quickly when their activity shows variation and identify the cause. This will help us understand how to maximise their productivity as well as monitor for any biosecurity risks,"
Dr de Souza said.
Understanding bee behaviour will give farmers and fruit growers improved management knowledge enabling them to increase the benefit received from this free pollination service. It will also help them to gain and maintain access to markets through improving the way we monitor for pests.
"We're working with the University of Tasmania, Tasmanian Beekeepers Association, local beekeepers in Hobart and fruit growers around the state to trial the technology. Many growers rely on wild bees or the beekeepers to provide them with pollinators so they can improve their crops each year. Understanding optimal conditions for these insects will improve this process,"
Dr de Souza said.
To attach the sensors, the bees are refrigerated for a short period, which puts them into a rest state long enough for the tiny sensors to be secured to their backs with an adhesive. After a few minutes, the bees awaken and are ready to return to their hive and start gathering valuable information.
"This is a non-destructive process and the sensors appear to have no impact on the bee's ability to fly and carry out its normal duties,"
Dr de Souza said.
The next stage of the project is to reduce the size of the sensors to only 1mm so they can be attached to smaller insects such as mosquitoes and fruit flies.
Under normal circumstances mitochondria use glycolysis products like pyruvic acid, and fatty acids. The latter are broken down in the matrix as is pyruvate to acetyl Co-A, which is fed into the Krebs cycle to produce CO2 and reducing equivalents in the forms of carriers like NADH. See a good biochemistry text for details of mitochondrial metabolism.
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The reducing equivalents (e.g. NADH) are fed into the transmembrane electron transport pathway, and the pathway of the electrons made available leads to the expulsion of hydrogen ions (protons) from the matrix.
The impermeability of the inner membrane results in the formation of a large concentration and electrical gradient and a potent electrical potential.
This electrical potential causes protons to move back across the inner membrane through the large ATP synthase protein complex that passes across the inner membrane. Passage of the protons powers a mechanical motor that brings phosphate ions and ADP into forced contact, fusing them into ATP.
The ATP migrates out of the mitochondrion through a channel in exchange for more entering ADP.
Water exists in two spin isomers, ortho and para, that have different nuclear spin states.
In bulk water, rapid proton exchange and hindered molecular rotation obscure the direct observation of two spin isomers.
The supramolecular endofullerene H2O@C60 provides freely rotating, isolated water molecules even at cryogenic temperatures. Here we show that the bulk dielectric constant of this substance depends on the ortho/para ratio, and changes slowly in time after a sudden temperature jump, due to nuclear spin conversion.
The attribution of the effect to ortho–para conversion is validated by comparison with nuclear magnetic resonance and quantum theory. The change in dielectric constant is consistent with an electric dipole moment of 0.51±0.05Debye for an encapsulated water molecule, indicating the partial shielding of the water dipole by the encapsulating cage. The dependence of bulk dielectric constant on nuclear spin isomer composition appears to be a previously unreported physical phenomenon.
Introduction
Water, like dihydrogen, has two different spin isomers, called ortho and para, which have different spin state symmetries.
In ortho-water, the spin state of the two proton nuclei is symmetric under particle exchange and the total nuclear spin has quantum number I = 1. In para-water, the spin state is antisymmetric and has nuclear spin quantum number I = 0.
Water spin isomerism is of relevance to a broad range of scientific fields from nuclear magnetic resonance (NMR) to astrophysics1,, and closely related to long-lived nuclear spin states, which also involve the slow interconversion of nuclear singlet and triplet states.
Physical properties of dihydrogen H2, such as heat capacity or thermal conductivity, depend on the concentration of ortho and para spin isomers.
Do the spin isomers of water also have different bulk properties?
Since water, unlike dihydrogen, possesses an electric dipole moment, the spin isomers of ortho and para water are expected to display a distinct response to electric fields. This effect was predicted theoretically; and observed in beam experiments10, but no bulk properties have been reported.
Although it is feasible to separate ortho- and para-water molecules in rarified molecular beams, , it remains challenging to study the separated isomers in the condensed phase, since rapid proton exchange obscures the spin isomerism in bulk water, and strong intermolecular interactions usually quench the molecular rotation at low temperatures.
Spin isomer-enriched water may be captured in an inert gas matrix and studied using infrared spectroscopy, but this approach provides little control over the molecular environment.
In contrast, the supramolecular endofullerene H2O@C60, composed of C60 carbon cages that each encloses a single water molecule, forms a well-defined lattice.
The synthesis of this material provides macroscopic quantities of a stable substance that contains isolated and freely rotating water molecules. It has been studied under a very wide range of physical conditions using various spectroscopic techniques1. Dielectric measurements were made on a single crystal of H2O@C60, but without anticipating, or observing, a dependence on spin isomer composition.
Figure 1a,b shows the molecular structure of H2O@C60 and the four lowest rotational energy levels as determined by neutron scattering, neglecting the observed splitting of the ortho-water ground state1, .
The energy levels are similar to those of water in the gas phase indicating that the water rotation is unhindered even at cryogenic temperatures.
The thermal equilibrium fraction of ortho-water molecules as a function of temperature is shown in Fig. 1c, using the energy levels of Fig. 1b and taking into account the degeneracies of the rotational levels. The equilibrium fraction changes rapidly in the vicinity of 15 K. Ortho–para conversion may therefore be induced by (i) allowing the sample to reach complete equilibrium at a temperature >15 K, (ii) rapidly cooling to <15 K and (iii) studying the behaviour of the sample as a function of time at the constant low temperature.
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Here we demonstrate that the bulk dielectric constant of H2O@C60 depends on the spin isomer composition of the encapsulated water molecules.
We find a time-dependent change in dielectric constant at 5 K that is due to different molecular polarizabilities of the ortho and para ground states.
The polarizabilities are extracted from the capacitance data and compared with a theoretical prediction that only requires knowledge of the dipole moment of H2O@C60 and the rotational constants of water.
The dipole moment is estimated from a high-temperature measurement of the molecular polarizability and found to be in very good agreement with recent predictions of 0.5±0.1 Debye.
