World Cup 2014 : The Symbolic First Kick

For Professor Nicolelis  it is indeed a  Symbolic First Kick !

Watch out for the opening ceremony  of the World Cup 2014 in  at the Arena de Sao Paulo next week. Amidst the uproar and exuberance there would be a moment of complete silence. A paraplegic youth wearing a robotic suit with an EEG sensor cap will be wheeled into the stadium.  He will  help himself from the wheelchair , advance a few steps and kick a soccer ball. The brain behind the spotlight event is Professor  Miguel Nicolelis of the Duke University, Durham, N. Carolina. A renowned neuroscientist  with special interest in the area of  Brain- Computer interface. Prof. Nicolelis   wants to showcase the immense potential and promises that science and technology hold for human race.   Prof. Nicolelis is providing proof  for a concept called Shared Control  where the disabled  person has to imagine  movements to empower his robotic limbs. Prof Nicolelis explains :    "Part of the higher order decision is done by the brain and the low-level movement is enacted by the robot.  Higher order decisions include "start walking" , "stop walking", "accelerate", "slow down", "turn left", "turn right", "kick the ball". 

A minimalistc view of the  exoskeleton is as follows : 

• EEG sensor cap which will pick up signals from the brain, 
• Backpack that will carry a computer,  battery power and hydraulics; computer would translate the brain signals to the robotic limbs, battery and hydraulics together will empower the robotic limbs  
• Gyroscopes to keep balance 
• Sensors in the Footplates to monitor  steps and feed the info back into the system. 

In the meanwhile  US FDA( United States Food and Drug Administration) has just recently been approved  . the DEKA Arm . That means the product is now available in the market.   Designed to be of great help for  upper arm amputees, the project was conceived and conducted by the US Army Research Office  less than a decade ago.  Videos demonstrate   the capabilities of the prosthetic arm from picking up a tiny grape to more complex tasks. This bionic arm  is comparable to the human arm in size and shape but not in looks. The semitransparent outer cover retains the robotic look. The electronic package is a set of   EMG (electromyograph) electrodes together with additional assembly of switches, sensors etc.  The EMG electrodes pick up signals from muscle/device interface sends to a micro processor which ensures the desired movement. If you are wondering about the unusual name of DEKA for a bionic arm, well it stands for the inventor entrepreneur Dean Kamen.  He has about 400+ US and international patents to his credit and that is the recipient of several medals and honor including the National Medal of Technology and Innovation.  Dean Kamen shot into fame with  the personal vehicle Segway. 

1.Kickoff looms for demo of brain controlled machine : Science 6th June 2014, Vol. 344, pages 1069-70
2.A Brain-Machine Interface enables bimanual arm movements in monkeys. Ifft etal  Science Transl.Med. 6 Nov. 2013 Vil.5 pages 210ra154
3.FDA approves high-tech prosthetic arm Nature 15th May 2014 Vol.509 page 264

Blame it on Food!

There is no love sincerer than the  love of food  

-George Bernard Shaw, (Man and Superman, 1902)

We humans have a Love-Hate relationship with food. We love to eat ad libitum,  and then   bear a grudge against food for every minute ailment.  If there are TV channels   dedicated to cookery shows 24/7  and then there are  shows that  teach you  how to shed what you ate. And those who afford appoint  a personal dietitian.  New eateries crop up every day reducing the distance from home, why they even volunteer  home deliveries. Earlier one used to insist-  No MSG please, but now?  Low carb, no salt, no sugar, no trans fat, gluten free?  You name it and you get it.  Feasting or Fasting  food  opens up  great business opportunities.   Science can't be far behind can it? .  

Professor Valter Longo , director of Longevity Institute University of Southern California is interested in understanding the molecular biology of health and aging and longevity as a function of food(1,2).  He is of the opinion that fasting  is more advantageous  than dieting. Well, as he discusses CR(calorie restriction or dieting), IF (intermittent Fasting) and PF (periodic fasting)  we realize that there are  several   ifs and buts. He  points at  studies conducted  in mice and men.  His team monitored the changes in the levels of biological markers for aging and health : IGF-1, IGFBP1, glucose and insulin during fasting. Fasting for 3 days brought down the levels of the these by almost 30%.  IGF-1( insulin like growth Factor-1) and insulin have been strongly implicated in accelerated aging and cancer.   Longo and team contend   that studies  have in general established the beneficial effects of  fasting in cancer patients. Of course fasting  in combination with   chemotherapy; mind you  the two are not mutually exclusive.  It is suggested  that even from the perspective of looking good,  regular fasting is  an healthier alternative to cutting down on calories. Looks like we are on a path to rediscover the benefits of fasting. In any case several civilizations and religions have time immemorial been  encouraging  the  practice of fasting at varying frequencies for various reasons .    

March 2014 issue Cell Metabolism carries another paper from  Longo's group(3). This is a study aimed   to understand the link between the level and source of protein, amino acids aging, diseases and mortality.  This study  covered 6381  individuals of both sexes  in the 50+ age group.The epidemiological data from a US National Health Survey was corroborated with mouse and cellular studies. The team monitored the levels of  markers for biological aging such as IGF-1 well as  other vital and relevant parameters of the participants. The study obviously has its limitations, the researchers are aware of that. Nevertheless they conclude "our findings suggest that a diet in which plant based nutrients represent the majority of the food intake is likely to maximize health benefits in all age groups."  In the same issue of Cell Metabolism Solon-Biet et al (4)  provide further experimental evidence   that "low protein high carbohydrate diets are associated with longest lifespans".  They monitored the fluctuations of another marker mTOR, which is known to positively influence mice's lifespan. 

The papers though  interesting  were  intriguing.   Because  as mentioned before, these are conditional findings;  several ifs and buts   modify each  finding, and  complex  interlinked pathways and  phenotype and genotype traits   are at work.  
  
Tailpiece:
Here is a 440V jolt for all of us   by Libert etal (5).  

"Smell  is an ancient sensory system present in organisms from bacteria to humans. In the nematode C. elegans  gustatory neurons regulate aging and longevity. Using the fruitfly Drosophila  melanogaster , we showed that exposure to nutrients, nutrient derived odorants can modulate life span and partially reverse  the longevity-extending effects of dietary restrictions. .................................................................................olfactory regulation of life span is evolutionarily conserved. 

Soon this will be true for   mice and men!.      

Bon appetit

References:

1. Fasting Molecular mechanisms and clinical applications: 
    Longo and Mattson  Cell Metabolism-Vol.19, issue 2 p181-192, 4 Feb. 2014 

2. Fasting cycles restrict growth of tumours and sensitize a range of cancer cells to    
    chemotherapy.                                                                                                              Lee etal Science Translational Medicine  Vol 4, 124- 127, March 2012

3.Low protein intake is associated with a major reduction in IGF-1,cancer and overall       
   mortality  in the age 65 and younger but not older population                                             Levine etal Cell Metabolism  Vo.19 Issue 3 p407-417 March 2014

4. The ratio of macronutrients not caloric intake dictated cardiometabolic health, aging    and   longevity in ad-libitum fed mice- 
   Solon-Biet et al  Cell Metabolism Vol. 19 issue 3 p418-430, March 2014

5. Regulation of drosophila lifespan by olefaction and food derived odours 
    Libert etal Science 315, 1133 2007

Long Live Henrietta Lacks!

He La, the  play which won the Scottish Theatre Fringe Award for the best production at the Edinburgh Festival 2013,  ran to packed  houses in Jagriti Theatre. Adura Onashile the solo performer  unfolded the little known story of Henrietta Lacks, immortalized as HeLa, the  human cell line that defies death  and  grows in petridishes in the laboratory on which  medical and biological  research is done world over.   

It was in 1950 that Henrietta Lacks consulted Dr. George Otto Gey at the Johns Hopkins Hospital, Baltimore. The diagnosis :  cervical cancer. Dr. Gey had been seeing cancer patients for quite some time.  Hell bent on understanding the disease better and thus zero in on a cure, he routinely collected cancer cell samples from patients.  If only he could grow them  in the laboratory ! The collected samples were coded  with the first two letters of the patient's first and last names. And that is how Henrietta Lacks became HeLa. Of the several thousand samples collected,  only HeLa  demonstrated the unusual ability to survive and multiply   in petridishes. Thus the first   immortal human cell line HeLa was borne.  Since then for biomedical research  HeLa cells have  become the crucial and inevitable raw material. HeLa cells  standardized the  procedures and processes  for experimental  research. Scientists now could compare and contrast their results, repeat and reproduce their experiments  on a common platform: everyone was using HeLa cells.  

When Dr Gey took samples from his patients, there were no laws  on medical  ethics in place. Dr Gey's intentions were purely scientific. He freely shared the samples with other researchers. He never attempted to patent them either.  In 1951 The Tuskegee Institute took up the responsibility of mass producing HeLa cells and supplying it for research,  this too was a non-profit mission. Necessity not only gives birth to invention (also called discovery) but also its twin brother Business.  As demand  grew  He La production  moved into the  hands of  profit-makers. Currently HeLa cell line is available from certain pharmceutical firms for a price. It is important to mention here that Henrietta's descendants never received any benefits from any of these business ventures.In fact  it was only in 1973, that they even came to know about the existence of HeLa cells and its true identity.  In fact  Rebecca Skloot  mentions that they are too poor to afford health insurance

In 1950, 30 year old Henrietta Lacks had  entered the Johns Hopkins Hospital and walked into the  ward set aside for COLOREDs in the Johns Hopkins  Hospital, because that was what she was- a woman of African American origin. Today, if alive she would have touched 84 and as it says in the play how  would she have felt  to know that anyone who has taken a pill stronger than aspirin owes it to  her?  

Immortal Life of Henrietta Lacks: by Rebecca Skloot (Reprinted by  Broadway Books 2011, ISBN-10 9768140005218). 

Henrietta Lacks

• 
  

Cancer Cure : Brave New Strategies

Cancer Ward  was first  published in 1967.  Its political implications  have  expired, but the emotional trauma of the terminally ill cancer patients continues still, worldwide. Pulitzer Prize winner (2011)   The Emperor of All Maladies   resonates with the  very  same despair-  If only ....... there could be a cure!   4th of February happens to be World Cancer Day. Most appropriate day for us to examine the latest  in the treatment of cancer.  Have we hit upon anything new? 

Recent issues of both  Nature and Science are unanimous in hailing  Immunotherapy as a paradigm shift in the treatment of cancer. What is so special about immunotherapy, that it tops the list of Newsbreakers of 2013?  The fundamental difference is that  till now all treatments, (whether the the hot ray or cold knife as Mukherjee puts it), focused on the cancerous tissue whereas  the new mindset  aims  to boost,  equip and train body's immune system to stand up against cancer cells. The thought process had begun  almost 125 years ago, when  William Coley,  a surgeon at the New York Cancer Hospital ( now part of Memorial Sloane Kettering Cancer Center), accidentally came across a cancer patient whose tumor had miraculously disappeared after a bacterial infection. Coley was excited and interested. He  was correct in assuming that the infection  was instrumental in the disappearance of cancerous growth and quickly began a series of  tests on other cancer  patients. Coley deliberately infected them with a similar bacterial concoction. Though proved successful, this line of treatment was soon discontinued for two reasons. One: clean and quick  radiation therapy entered the stage in early 1900s, second: standardized and reproducible procedures for infection therapy (actually vaccination therapy) were not yet in place, bacterial concoction had to be adjusted to suit each patient. Hundred plus years later doctors and scientists dug up Coley's records and came to the conclusion that  the bacterial infection might have rejuvenated  cancer patient's  immune system somehow.   And that is one of the anchoring points of  modern day immunotherapy : boost, equip and train body's immune system  to attack cancer cells. While there are several drugs to ensure the general  robustness and readiness of the immune system, how to train and equip them to attack the cancerous growth? 

The most remarkable  feature  about vertebrate immune system is adaptability. And it is this feature that is being  exploited extensively  in immunotherapy. Immune system, body's defense force, comprises of  white blood cells (also called  leucocytes). They are indeed organized as an army with  several cadres entrusted  with very specific and exclusive responsibilities.  Alert watchmen, the dendritic cells (DC)  are ever  on the patrol,  always on the look out for foreign intruders, enemies ( scientific term Antigen).  If they  spot anything new  they will grab  a sample and carry it to the soldiers' training center. Soldiers in training, the immature T cells,  will puff and sniff at the foreign body and recognize it as the enemy .  Memory T cells will  lock up the information in their data bank for present and future use;  helper  T cells will  produce  weapons (antibodies against the antigen), and killer T cells   will  go all out for the enemy. Regulatory T cells meanwhile will take care of the supply logistics. But here is the catch - the whole system is geared to work   against aliens.  Cell division is a natural process, only difference is that   in cancerous tissues this process  is unstoppable. When the enemy is unidentifiable how  can a defense strategy be set up ?  

Scientists are trying out various  tricks. One approach  is to empower the patrollers, the dendritic cells, to recognize the cancerous cells. Immature DCs are taken out of the patient's blood, differentiate and activate them in culture, load them with tumor specific antigens  and then inject the cells back into the patient"  explains immunologist Karolinska Palucka. The vaccine Provenge for the treatment of prostate cancer  falls under this category. Another approach is to nudge the killer T cells. Immune system has a number of checks and balances to ensure that  it doesn't turn suicidal, means it doesn't attack  body's own cells.  Several oncologists from various research hospitals individually and collectively  observed that tinkering with these checks and balances often proved helpful.  Dr James Allison noticed that  a protein identified as CTLA-4 is one such check point protein. It doesn't allow the killer T cell to demonstrate its full capability.  Allison argued  that if he can   turn off CTLA-4,  the killer T cell   would realize its full potential. Could it then be coaxed to   attack  the tumor cell?.  Allison used a specially designed protein, (a monoclonal antibody to be precise), in mouse models for melanoma (skin cancer) and got very successful results. After decades of intense studies and trials, Bristol-Myers-Squibb finally received   US FDA approval in 2011. Currently in the  market as Ipilimumab for treatment of melanoma , its  price tag is a whopping US$120,000 for a course and it isn't clear minimum how many courses one needs.  

Tinkering with the immune system may not be without risks.  But as Couzin-Frankel concludes : "One book has closed, and a new one opened. How it will end is anyone's guess"

1. Cancer Ward : Alexander Solzhenitsyn
2. Emperor of All Maladies- A Biography of Cancer  : S Mukherjee 
3. Cancer Immunotherapy   Nature   504,(7480). ppS1-S1719/26 December 2013

4. Cancer Immunotherapy Science   342, p1432-1433, 20th Dec 2013

  

Taming Hydrogen :Enzymatically

New Year ushers in new hopes and sets aggressive targets. 2014 is no different.   Toyota, the Japanese auto giant unveiled  the  concept version  of a  hydrogen car  or the FCV (fuel cell vehicle)  at  the Consumer Electronics show  currently being held at Las Vegas. The cars will be marketed in California next year and even  the blueprint  for Hydrogen gas stations are ready The car, it is claimed   can reach a maximum speed of 100mph and accelerate to 60mph in 10 seconds.Moreover a fulltank run of about 300 miles is assured. Toyota didn't specify a price , but a humble guess is:anywhere between 50,000  -100,000 USD. (1). Hyundai and Honda motors are also fast catching up

Hydrogen,is the  simple, unassuming numero uno of  the periodic table.  Henry Cavendish, the eighteenth century chemist was the  first  to identify  this colorless odorless gas  and realize that upon combustion it yielded  water. That is why Lavoisier later named it   Hydrogen  that which yields water.  With just one electron and one proton, how complex can it chemistry get? Sure it is simple but  explosive too. It can burst into flames at the slightest provocation. Now combustibility is the hallmark of fuels, and naturally questions popped up among scientific circles. Could hydrogen be the ultimate fuel, because the product of its combustion is the benign and benevolent  Water. Can there be a greener fuel? However easy  combustibility, though highly desirable for a fuel, makes its storage and handling extremely difficult and dangerous.  Scientists have been trying  for decades to tame hydrogen. Indeed  there are success stories, but the price tags are  so exorbitant  that hydrogen as a fuel isn't a commercial success yet .If storage, handling and transportation of hydrogen become  cheaper and viable (on par with that of the crude oil,) then FCVs,  will soon be within common man's reach. Persistent efforts at all levels are on to tackle issues.  It is in this context that we must once again acknowledge help from the   lowly microbes.   

In a recent issue of Science magazine Schuchmann and Muller (Molecualr Microbiology and Bioenergetics, Institute of Molecular Biosciences, Wolfgang Goethe University Frankfurt Germany)  report (2,3)a clever way of  restraining this mischievous molecule. The method may even be economically viable.  Schuchumann and Muller  found a perfect ally in Acetobacterium woodii. These microbes thrive at room temperature , need no oxygen (or in more scientific terms they are anaerobic. It contains an enzyme Hydrogen Dependent Carbon dioxide Reductase,(HDCR) which can chemically link hydrogen (hydrogenase ) to carbon dioxide or peel them off (dehydrogenase) if necessary. In  other words the reaction is reversible. The reaction as depicted  below is quite simple, and devoid of the usual complexities of enzymatic catalysis. Earlier Reda et al(4) reported the use of an electroactive enzyme to bring about the reversible reaction of formate , but  hydrogen molecule did not play any direct role there.

                 

                         

Formic acid is a liquid,and  noncombustible which solves the problem of  storage , handling and transportation.  Schuchmann and Muller point out an  additional advantage; possibility of using  syngas, as the input  stream. Syn gas  is a mixture of  carbon monoxide, carbon dioxide and hydrogen. (CO, CO2 and H2,)  and is produced in bio gas generators. 

The concept of trapping hydrogen in carbon dioxide is not new (4,5). There are chemical methods to do  it, however  they all suffer in one way or the other either  by way of low yields, high temperature requirements or expensive catalysts.   Schuchumann and Miller are hopeful that their discovery  could be a biotechnological breakthrough.

But there are more  road blocks in the path of FCVs :for example   industrial scale manufacture of hydrogen  may not be so green. 

 References:

1. Toyota's Hydrogen car 2014

2.Direct and reversible Hydrogenation of CO2 to formate by a bacterial carbon dioxide:

   Schuchmann and Muller, Science Vol 342, p 1382-1385 , 2013 

3.An enzymatic route to H2 storage  Pereira Science 342, p,1329-30, 2013 

4.Reversible Interconversion of  Carbon dioxide and formate by an electroactive enzyme:   Reda et al Proceeeding of the National academy of Scienes (USA) Vol. 105(31)  pages  10654-10658, 2008

5..Reversible hydrogen storage using CO2 and a proton switchable iridium catalyst in   

   aqueous media under mild temperatures and pressures:  Hull etal  Nature Chemistry : 

   Vol.4,    pages 383- 388,  2012

  

  

Evolution has no End point.

This is breaking news. Scientists have decoded the genomes of two types of snakes , the cobra and python. These results are published in  two separate papers in the recent issue of Proceedings of the National Academy of Sciences, U.S.A. (1,2) Both teams were seeking an "evolutionary" answer to  the peculiar eating habits of these snakes. How did one group develop poisonous venom to kill the prey  and the other acquire enough muscle power to swallow  the prey? 

According to  the tree of Life   the common ancestor of all snakes is the lizard. One school of thought  is that when circumstances forced the lizards to  live in water, evolution shaved off their legs to turn them into more efficient swimmers. Another group is the of the opinion that   at some point perhaps due to adverse climatic conditions, lizards had to take shelter underground and thus  burrowing sawed off the legs.  The verdict is not yet out, but  scales could be tilting a bit in favor of burrowing, because of Najash the Fossil. This fossil of a 90 million year old burrowing snake  sports  a pair of hind legs. Well, getting back to the  cobra- python story perhaps there is a clue in the comparative body sizes of the snake and its  prey;  small agile snakes developed the venomous route to shock and kill their small prey while  big snake like the python  relied more on its own muscle power to subdue  bigger prey. 

Tree of Life  by German Scientist Ernst Haeckel  in the Evolution of Man 1879
Courtsey : English Wikipedia Tree of life (Biology)

Vonk et al set out to understand the molecular biology  of cobra venom.  Venom  is  a concoction of toxic  peptides.  Which genes  code for these peptides? Perhaps that will yield an evolutionary  clue? They sequenced the genome of the king cobra  and  linked the toxic peptides to about 20 odd  genes. They found that the venomous pathway has a pancreatic origin. They also hint at the possibility that the potency of the venom must have increased over a period of time to compete with the prey's ever alert defense mechanisms. Surprisingly the research team found nothing extraordinary in the genes for specific  toxins. These were genes that coded for peptides  used for other bodily functions elsewhere, such as  blood clotting  or BP lowering...etc.  But what intrigued them was the presence of multiple copies of these genes;  perhaps ready for easy and potent mutations. Decoding the genes for venom is a great help to the pharmaceutical field where, be it from any source, venom is worth its weight in gold.  Because venom could hold secret formula for a variety of drugs. Several cardiovascular and CNS drugs are modeled on peptides found in snake venom which exhibit similar behaviour(3). In France, scientist Pierre Escoubas  has ventured to establish a company VenomeTech "to lead the development of new drugs in the area of of pain cancer and diseases of the central nervous system", as the company's website proclaims.  

The story is slightly different in the case of pythons. Pythons  can starve for months at a stretch. But then when they get to eat a sumptuous meal, their internal organs balloon to accommodate the prey and metabolic rate multiplies several fold .  How does this happen?    Castoe's team discovered "massive rapid  changes in the gene expression that coordinate  major changes in the organ size and function after feeding;"  corresponding genes in  humans  perform  rather insipid  jobs in the area of metabolism, development and pathology. Castoe and his team  went one step ahead and compared  the genomes of the python and the Cobra.  They found 7442 genes common for both as well as other vertebrates. They suggest that snake genomes have differentiated and evolved much faster in response to the  peculiar  constraints they encounter.  

That brings us to a curious question.  Does that mean cobras and pythons have reached the plateau  of their respective evolutionary process?  Like as some scientists  assume  Humans are the ultimate intelligent beings ? Far from it. Prof. Richard Lenski at Michigan State University, USA has been studying the evolutionary saga of Escherichia coli for the past two and a half decades.  His experiments demonstrate that evolution never stops; Oh yes, it might  accelerate or slow down , but never stops even in an unchanging environment .   




1. The king Cobra genome reveals dynamic gene evolution and adaptation in snake venom systems: Vonk et al PNAS 110 (51) pages   20651-20656, 2013

2. The Burmese python genome reveals the molecular basis for extreme adaptation in snakes. Castoe et al PNAS 110(51) 20645-2065, 2013. 

3. From toxins to treatment-  Kupferschmidt,  Science 342, 1162-1164, 6 Dec. 2013 

4.The Man who bottled evolution : Elizabeth Pennisi, Science 342 , 790-793, 15 Nov. 2013 

Shaping memories: in Men and Materials

Roshomon (1950) was a  unique film  in which Kurosawa artistically and  elegantly  showed     perceptions are  colored by  personal bias.  Eyewitness accounts could differ widely. Could it be that we see what we want to see? Or could it be that memory shapes and stores  events to suit individual tastes?  Elizabeth Loftus, (Professor at the Dept. of   Psychology  and Social behavior,  University of California, Irvine, USA) prefers to use the term "corrupted memory". Her research studies also suggest  that  human mind is capable of manufacturing memories and holding on to them as real.  Memory is not a "one time, one bit information filed and forgotten" It is  a dynamic  process, and involves  reconstruction and  reprocessing of data.  Many agree with Loftus when she insists that   "eyewitness accounts do not run like a video recording",  and "an individual's beliefs, desires and imagination can fuel misremembering and information from external sources will exacerbate false recollection". 

Having said that it is this very  same memory that guides you back home  in the evening after a day's hardwork. You never tend to lose the way. The route map is engraved in our memory, from home to school/office/market/busstop/ airport wherever you go, whatever be the distractions enroute,  guides you back to home again.  Fed up working with inert, dumb materials,  scientists asked the question: could we engrave such  route maps in materials? Can we enable them to  remember and respond? After all biological materials  demonstrate intelligence. Why can't we teach    a   diamond to turn   into a lump of graphite and back again when necessary?    And why not, after all both diamond and graphite are basically carbon, albeit in different avatars.

Well it is true that we haven't yet reached the diamond-graphite stage yet,  but scientists have been able to design other  intelligent materials.   Shape Memory (SM) materials belong to this class and as the name implies their memory is limited to shapes. They have the ability  to switch   from a permanent  to a temporary form and back again. This switch over could be triggered by a variety of agents: pressure,  heat, magnetic field, electricity or light.  SM  materials have wrought a revolution in  frontier technological applications such as space, robotics, bio medicine etc. The simplest and oldest member in this group is perhaps our humble rubber and its capabilities can be easily demonstrated with  a common rubber band.   Resilience,  the ability to accommodate strain without cracking or crumbling, is the key factor for  a  material  to exhibit SM behavior.  In polymers,  their long chain structure and viscoelasticity   are facilitators. In  alloys the  process is explained through alterations in crystal structure. Nitinol, an alloy of nickel and titanium was the first shape memory alloy to be designed.     

So far brittle materials such as ceramics couldn't be trained to remember their shapes because they crumbled under the burden  of (memory) strain.  But now Li et al have found a way to circumvent that. This collaborative work involves researchers from Massachusetts Institute of Technology, USA and Nanyang Technological University, Singapore.  Li et al report their finding in the 27th September issue of Science.  Their test material is polycrystalline zirconia with small amounts of intentional impurities such as cerium oxide  or yittrium oxide .  Zirconia  is known to undergo  transition from tetragonal to monoclinic form without diffusion.  The investigators  used micrometer size pillars as test samples as this enabled them   to get high surface area at the same time allowed them to  keep  the   volume low.  This is a small step leading to a giant leap because ceramics are ideal workhorses for high temperature applications. 



References:

1. Misinformation can influence memory for recently experienced highly stressful events 
    Morgan et al.,International Journal of Law and psychiatry 36, 11-17, 2013

2. Evidence based justice: corrupted memory,  
   Nature Vol. 500  268-270, Aug. 14, 2013

3. Eyewitness testimony in the Lockerbite bombing case 
    Elizabeth Loftus Memory, vo.21 584-590, 2013

3.Shape memory and superelastic ceramics at small scales 
    Lai et al., Science : Vo. 341,1505-1508 , 27 Sept. 2013