Hormesis is the name given to the processes by which a little damage at the cellular level can actually be beneficial, as it spurs repair and maintenance systems to greater efforts - the result is a net gain. Here researchers demonstrate one method of inducing hormesis in nematode worms: "As organisms age, cellular proteins, lipids and nucleic acids sustain damage that can lead to functional deficits in tissues and, ultimately, death. The free radical theory of aging proposes that aging results, at least in part, from damage to cellular components by reactive oxygen species (ROS) ... Indeed, oxidative modification is a major form of damage detected in aging tissues ... Here, we report that hormetic chemicals can be modified to optimize beneficial effects and minimize toxicity in C. elegans, a model for studying aging in whole organisms. C. elegans is well-suited to this problem due to the short lifespan, ease of genetic manipulation and transparent anatomy. First, we examined whether lifespan extension is common among biological toxins with various chemical structures and mechanisms of action. In a small screen of natural phytochemicals, we identified two ROS generating compounds, plumbagin and juglone, which extended lifespan at subtoxic doses. Mean lifespan extension by plumbagin was dependent on SKN-1, a cap'n'collar transcription factor that promotes antioxidant gene expression in response to oxidative stress. We further screened a collection of six plumbagin analogs, identifying three additional naphthoquinones that activated expression of a skn-1 target. One of these could extend lifespan over a larger range of doses than plumbagin, demonstrating the utility of stress hormesis mechanisms as promising prolongevity intervention."
Monthly Archives: July 2011
Snapping out of the Pro-Death Trance
From TechNewsWorld: "In America, a large part of funding for regenerative medicine comes from the Department of Defense, whose goal is to repair soldiers who come home wounded. That is an effort everyone recognizes as important. Yet, when it comes to repairing older people whose hearts and lungs are failing, society seems at peace accepting their demise because that is all humanity has ever known - a state of mind that some call the 'pro-death trance.' ... A Swedish hospital recently announced that a cancer patient was saved after doctors grew him a new windpipe in the lab using a synthetic structure and the man's own stem cells. That might have sounded like science fiction just a few years ago, but today it is landmark news. Regenerative medicine has the ability to usher in radically longer and healthier lives, yet few are considering the implications. The ability to grow new replacement parts for humans when original organs break down is a game-changer when it comes to extending human 'health spans' - the amount of time one is alive and healthy. A handful of human subjects have already benefited from innovations in this area and dozens of organs have been successfully grown in the lab, including a rat heart. ... The coming changes will be enormous - but on the whole, positive. Why then, is there no sustained dialog about how to get to that point sooner? ... Humans now have the opportunity to live much longer and healthier lives - for the greater benefit of all. It is time to break free from the pro-death trance and work toward speeding the revolution."
Link: http://www.technewsworld.com/story/America-Its-Time-to-Snap-Out-of-the-Pro-Death-Trance-72907.html
A Question and Answer Session with Aubrey de Grey
Over at h+ Magazine you'll find a question and answer session with Aubrey de Grey that covers some old ground and some new ground. The SENS Foundation, which de Grey cofounded, is presently deploying a modest million-dollar yearly budget to work on the biotechnologies needed to repair the cellular and molecular damage that causes aging. A great deal of that budget presently goes towards the first of the Foundation's programs, an effort focused on using bacterial enzymes to break down harmful waste chemicals that build up in our cells and contribute to a range of age-related diseases and degenerations.
I should mention that SENS Foundation funding is due entirely to philanthropic donations - including those of a few high net worth individuals - and I know that many of the readers here are long-standing supporters dating back to the years when the SENS Foundation's work was a program of the Methuselah Foundation. I find it very gratifying to see that so much has been made of the early efforts, when it was a matter of a few dollars given at time. I would hope that the rest of you feel the same way.
The SENS Foundation will also be hosting the forthcoming SENS5 conference in Cambridge at the end of August - there's a lot going on at the moment. But back to the h+ Magazine piece:
H+: SENS describes a whole battery of medical treatments that could theoretically defeat the aging process. These treatments range from relatively simple ones like injecting people with enzymes that can break down tough wastes inside of cells, to highly advanced ones like genetically altering trillions of somatic cells in full grown adults. Considering the differential technical challenges, what SENS therapies will most likely become available first, and which will be developed last?
AdG: Some of them are already pretty close: probably the closest is in fact not the enzyme therapy you mention, but the use of vaccines to eliminate extracellular aggregates (especially amyloid). But when we consider the others, actually I wouldn't like to make the call, because the hardest ones are the ones that the SENS Foundation and I are prioritizing in terms of the early research. In other words, we're hoping that they will start to catch up with the easier ones. I suspect that the challenge of genetically modifying a high proportion of cells by somatic gene therapy will have been largely solved before we complete the development of all the genes that we want to introduce.
...
H+: Are you worried that a single company or government might obtain the secrets to longevity first and then use its monopoly on the science to hold the human race hostage forever (or even for just a long period of time)?
AdG: There's no chance whatever of this scenario, because the defeat of aging will depend on the simultaneous application of a lot of different interventions, all of which will first have been developed in the laboratory rather than in humans.
There's a lot more in that vein, so read the whole thing. The point on gene therapy in the quote above is an interesting and important one. A great many very promising demonstrations in the laboratory depend upon gene therapy in one form or another - take the method of largely preventing atherosclerosis I pointed out earlier today for example. If we want to see these lines of research become more than simply interesting technology demonstrations then selective, tissue-specific gene therapy for humans must become routine and safe.
Arguing Against a Correlation Between Blood Type and Aging
Does blood type in any way affect longevity? A resounding "maybe" from what little work exists on the topic, which suggests that if there is any effect then it is small in comparison to other factors. But we'll never know unless the research community looks into the matter, and so here is another batch of evidence to add to the pile: "Centenarians are the best example of extreme human longevity, and they represent a selected population in which the appearance of major age-related diseases, such as cancer, and cardiovascular diseases among others, has been consistently delayed or escaped. The study of the long-lived individual genetic profile has the purpose to possibly identify the genes and the allelic variations influencing extended life expectancy, hence considering them as biomarkers of age-related diseases onset and development. The present study shows no significant differences between allelic variations of ABO blood groups among a group of centenarians from Western Sicily."
Gene Therapy Versus Atherosclerosis
Via EurekAlert!, news of a promising study in rabbits: "A one-dose method for delivering gene therapy into an arterial wall effectively protects the artery from developing atherosclerosis despite ongoing high blood cholesterol. ... As applied in our study, the introduced genes can produce proteins that counteract the fundamental processes that drive atherosclerosis, including preventing lipid accumulation inside the artery wall and decreasing recruitment of inflammatory cells. We found both of these effects. ... Gene transfer would move the production of the therapeutic 'drug' (in this case a therapeutic gene) directly to the site of atherosclerosis development: the blood vessel wall. The approach maximizes delivery of the drug to the artery wall and minimizes side effects in the rest of the body. ... The deployed gene produces a protein that is likely responsible for the beneficial effects of high-density lipoprotein, or HDL, commonly known as good cholesterol. This substance is apolipoprotein A-1, or apoA-1. It pumps out harmful cholesterol from the scavenger-type cells that ingest fats and congregate in early atherosclerotic lesions. ApoA-1 appears to remove cholesterol from the lesions and is capable of transporting it to the liver, where it can be excreted from the body. Lack of a suitable vector to transfer apoA-1-manufacturing genes into the cells lining the arterial wall has hampered the progress of this approach. Normally apoA-1 is produced by cells in the liver, stomach and intestine and enters the artery wall only after circulating through the blood. [The] researchers successfully used a helper-dependent adenovirus (HDAd) as the vehicle to transfer a genomic clone of rabbit apo-A1 into the carotid artery. This large blood vessel sends oxygenated blood to the brain. After the vector was infused into the artery, the gene was taken up almost exclusively by the cells in the thin layer that lines the carotid's inner surface and is in contact with circulating blood."
Link: http://www.eurekalert.org/pub_releases/2011-07/uow-gtd071911.php
To Learn How Cryopreservation Works in Practice Start by Reading the Case Summaries
Cryonics, as I'm sure you're all aware, has for decades been the best and only shot at a long life in the future for people who die before the advent of rejuvenation biotechnologies capable of reversing the damage of aging. That is a massive number of people, possibly including you and I unless we get our act together - and sadly, all too few will choose to be cryopreserved, even though they have the opportunity and the means. Cryonics is, in essence, a form of indefinite low temperature storage of the body and brain immediately following death. It is carried out with the reasonable expectation, based on present scientific knowledge, that it preserves the fine structure of the brain that stores the information of the mind - you might not be running, but all your data is backed up.
We can envisage the technologies needed to restore a preserved person to active life once again, and none of it is prohibited by the laws of physics. It most likely require a far greater understanding of the structure human brain, the ability to build a new body from scratch, the use of a molecular manufacturing technology base and swarms of nanoscale medical robots, capable of manipulating and repairing cellular machinery - and the computational power to support sophisticated use of these medical technologies. But all of these are foreseeable, and presently being worked on by a range of research groups. It isn't pie in the sky to expect there to be a chance of resuscitation for cryopreserved individuals. Their lives are on hold, but not gone - you are only irrevocably gone if you choose the grave.
But how does a cryopreservation work in practice? How does one go from the last weeks of life to being safely stored in liquid nitrogen, awaiting the future? As I've noted in the past, it takes a fair amount of organization to do well, and the regulatory environment surround end of life choices doesn't make a good cryopreservation any easier - you are not allowed to choose when to do it, and in most jurisdictions no-one is allowed to help you plan your death to be at the time of your choosing either. If you want to learn more about how a cryopreservation tends to unfold, then you should note that cryonics provider Alcor publishes case summaries on a regular basis, as patients are preserved. You'll find some referenced back in the Fight Aging! archives, and here are a couple of recent case summaries:
Case Summaries: A-1408 and A-2357:
This past quarter, Alcor cryopreserved two of its members. The first member, A-1408, lived just north of the Tampa, FL area. Alcor team members initiated a standby at the hospital for three days during the time the individual was listed as critical and medical providers anticipated that he might stop breathing. The member stabilized and Alcor ended the standby while continuing to monitor the patient's condition remotely. When his medical condition deteriorated again, Alcor was on the verge of initiating a standby for another member and therefore decided to request Suspended Animation to provide the standby this time.
On the afternoon of the fourth day of the standby (May 26, 2011), the member was pronounced, stabilized and cooled on-site, followed by a field washout. The transport commenced the next morning by commercial airlines and the patient was brought to Alcor with the surgical team at the ready. After the neuro cryopreservation ensued, member A-1408 became Alcor's 105th patient.
Wesley Du Charme authored a book: Becoming Immortal: Nanotechnology, You and the Demise of Death in 1995, which discussed the opportunity for virtual immortality through combining nanotechnology and cryonics. He lived life fully while always looking to the future; he joined Alcor in hopes of living in the far future.
....
The tests showed that Wesley now had pancreatic cancer with metastases to the liver and duodenum. At this point, the oncologist said that his condition was terminal and nonoperable, and Wesley would not respond to chemo or radiation treatments. When asked how long Wesley had to live, he responded with "...longer than three days, but less than six months."
Given Wesley's greatly weakened condition, the family desired to have him admitted to hospice care in Scottsdale, Arizona, close to Alcor. As Wesley was currently hospitalized, his physician who was supportive of the cryopreservation directives, prescribed TPN (Total Parenteral Nutrition) as a way to increase Wesley's strength and stamina to endure the trip to Arizona. Alcor personnel helped facilitate communication between the hospice facility and the family to finalize the admittance process.
You should read the whole PDF document, and be appreciative of the folk who were thoughtful enough to allow a detailed account of the arrangement of Du Charme's cryopreservation to be published. The end of a life and the terminal breakdown of a body's necessary systems are never pretty, and most people prefer to sweep all of that behind the curtain - and the same goes for the hundred small organizational details that go into managing death and cryopreservation. But if they aren't published, we don't learn.
Meditation May Help Women Cope With Hot Flashes
(HealthDay News) -- An easy-to-learn meditation technique can help ease the hot flashes, night sweats and insomnia of menopause, a new study says.
The University of Massachusetts research showed that mindfulness training, based on a Buddhist meditation concept, reduced the distress associated with hot flashes and improved physical, psychosocial and sexual functioning.
"The findings are important because hormone replacement therapy, used to treat menopause symptoms in the past, has been associated with health risks," said study author James Carmody, an associate professor of medicine in the division of preventive and behavioral medicine.
About 40 percent of menopausal women suffer from hot flashes and night sweats, which undermine their quality of life, the researchers noted. But since hormone replacement therapy has been linked with an increased risk of heart disease, breast cancer and stroke, Carmody observed that "not only are women looking for alternative treatments, it is an NIH (National Institutes of Health) priority to find behavioral treatments Read more...
Cardiofy Heart Care Supplement
New Report Details Uphill Battle to Solve the U.S.'s Pain Problem
Chronic pain affects at least one in three adults in the U.S., which is more than the sum total of those with heart disease, cancer and diabetes combined. For many of these 116 million Americans, their pain is severe and eludes available treatments. In addition to the human suffering, the monetary cost of medical treatment and lost productivity has reached $635 billion a year. [More]
New Report Details Uphill Battle to Solve the U.S.’s Pain Problem
Chronic pain affects at least one in three adults in the U.S., which is more than the sum total of those with heart disease, cancer and diabetes combined. For many of these 116 million Americans, their pain is severe and eludes available treatments. In addition to the human suffering, the monetary cost of medical treatment and lost productivity has reached $635 billion a year. [More]
The OTC Investor Article – International Stem Cell (ISCO) Aims to Become the “Intel(tm) of the Stem Cell World” By Justin Kuepper
International Stem Cell Corp (OTCBB: ISCO), a biotechnology company focused on therapeutic biomedical research and cosmeceutical products, operating in the same industry as companies like Geron Corporation (Nasdaq: GERN) and Advanced Cell Technology Inc. (OTCBB: ACTC), aims to become the premier supplier of human cells and cell based products to the rapidly growing regenerative medicine industry.
International Stem Cell Corp (OTCBB: ISCO) specializes in manufacturing pluripotent human “partheno-genetic” stem cells that can be converted into any of the many specific types of cells that will be needed as regenerative medicine moves from the laboratory to the hospital or physician’s office. ISCO’s cells have the same kind of ability to become any specific cell that might be needed for therapy as do the cells used by competitors like Geron Corporation (Nasdaq: GERN) and Advanced Cell Technology Inc. (OTCBB: ACTC). Unlike the cells used by these competitors, however, ISCO’s cells are not obtained from fertilized embryos that might otherwise mature into a human child. Instead, they are derived from un-fertilized human eggs that would otherwise be destroyed and have no capacity to become a human child. Thus, ISCO’s parthenogenetic stem cells have removed a major ethical barrier to the use of the most prolific class of stem cells available to science today. With its patent on using the parthenogenesis process to make the stem cells, the company plans to establish partnerships, collaborations and licensing agreements with larger pharmaceutical companies to eventually unlock significant shareholder value.
Please read the complete article at The OTC Investor here
International Stem Cell Corporation Starts Series of Preclinical Animal Studies of Neuronal Cells Derived From Human Parthenogenetic Stem Cells
CARLSBAD, Calif. (July 20, 2011) – International Stem Cell Corporation (OTCBB: ISCO) announced today the initiation of a series of preclinical animal studies of neuronal cells derived from ISCO’s proprietary pluripotent stem cells.
The studies will evaluate the in vivo safety and tumorigenicity of neuronal cells derived from ISCO's proprietary human parthenogenetic stem cells (hpSC), as well as their ability to develop into functioning dopaminergic neuron–like cells, a key milestone towards creating a cell-based therapy for Parkinson's Disease (PD).
ISCO uses unfertilized oocytes to create human parthenogenetic stem cells, an approach that offers a number of distinct advantages over other types of human stem cells. Like human embryonic stem cells (hESCs), hpSCs are pluripotent, and thus have the capacity to become almost any cell type in the body.
However, unlike hESCs, hpSCs can be created in a form such that cells from a single donor can be immunologically matched to millions of individuals.
Because no human embryos are ever damaged or destroyed in creating ISCO’s cells, they also avoid the ethical issues associated with embryonic hESC cells. ISCO maintains the world’s largest collection of research-grade hpSC lines.
Dr. Andrey Semechkin, the CEO of ISCO, comments: “The ability of neuronal cells to become a specific
type of neuron is one of the most important properties that these cells must have to be used in cell-based therapy of neurological disorders. These studies will bring us one step closer to our goal of being able to treat PD.”
Parkinson’s disease is a disease of the central nervous system that affects millions of people worldwide.
PD patients present a range of possible symptoms, some of which are known to be as a result of the loss of dopaminergic neurons in the mid brain. ISCO’s approach is first to derive neuronal cells successfully from hpSC and, second, to evaluate their safety, functionality and efficacy using a series of in-house in vitro and in vivo models.
About International Stem Cell Corporation
International Stem Cell Corporation is focused on the therapeutic applications of human parthenogenetic stem cells and the development and commercialization of cell-based research and cosmetic products. ISCO's core technology, parthenogenesis, results in the creation of pluripotent human stem cells from unfertilized oocytes (eggs). hpSCs avoid ethical issues associated with the use or destruction of viable human embryos. ISCO scientists have created the first parthenogenic, homozygous stem cell line that can be a source of therapeutic cells with minimal immune rejection after transplantation into hundreds of millions of individuals of differing genders, ages and racial background. This offers the potential to create the first true stem cell bank, UniStemCell™. ISCO also produces and markets specialized cells and growth media for therapeutic research worldwide through its subsidiary Lifeline Cell Technology, and cell-based skin care products through its subsidiary Lifeline Skin Care. More information is available at http://www.internationalstemcell.com .
To subscribe to receive ongoing corporate communications, please click on the following link: http://
Forward-looking Statements
Statements pertaining to anticipated developments, the potential production and benefits of stem cell
lines, and other opportunities for the company and its subsidiaries, along with other statements about
the future expectations, beliefs, goals, plans, or prospects expressed by management constitute forward-looking statements. Any statements that are not historical fact (including, but not limited to statements that contain words such as "will," "believes," "plans," "anticipates," "expects," "estimates,") should also be considered to be forward-looking statements. Forward-looking statements involve risks and uncertainties, including, without limitation, risks inherent in the development and/or commercialization of potential products and the management of collaborations, regulatory approvals, need and ability to obtain future capital, application of capital resources among competing uses, and maintenance of intellectual property rights. Actual results may differ materially from the results anticipated in these forward-looking statements and as such should be evaluated together with the many uncertainties that affect the company's business, particularly those mentioned in the cautionary statements found in the company's Securities and Exchange Commission filings. The company disclaims any intent or obligation to update forward-looking statements.
Contacts:
International Stem Cell Corporation
760-940-6383
Ruslan Semechkin, Ph.D.
Vice President
or:
Lippert/Heilshorn & Associates
Don Markley
310-691-7100
# # #
Cyclist who survived: Use your head. Use your helmet
James Cracknell, OBE (born 5 May 1972) is a British rowing champion and double Olympic gold medalist.
From Official JCracknell: On 20th July it's exactly one year since James Cracknell was seriously injured in a cycling accident in America. His helmet saved him. James has made a short film to encourage others to wear cycle helmets. To show your support, pass the film to your friends and most importantly, when you're out cycling, use your head. Use your helmet.
More about the cycling Accident from Wikipedia:
On 20 July 2010, Cracknell was hit from behind by a truck whilst attempting to cycle, row, run and swim from Los Angeles to New York within 16 days. The accident happened at around 5.30 am on a quiet stretch of road outside Winslow, Arizona. It has been reported that his bicycle helmet saved his life but he suffered a contre-coup injury to the frontal lobes of his brain. He is now back at home with his family, although recovery is expected to be still some time away.
Posted at Clinical Cases and Images. Stay updated and subscribe, follow us on Twitter and connect on Facebook.
How much vitamin D do you need? Distilling strong advice from weak evidence
From Nature News:
Vitamin D has been lauded in the media for preventing or treating multiple disease but most evidence is circumstantial or weak.
Despite this, some physicians recommend supplementation of up to 6,000 international units (IU) to compensate for the time that people spend indoors. This is less than what a fair-skinned person make in 30 minutes of exposure to the summer sun (without sunscreen).
The amount spent on vitamin-D supplements in the United States had risen 10-fold in 10 years.
Poor data is one reason that the IOM panel did not recommend higher doses for vitamin D supplementation in 2010. The IOM 1,000-page report recommended that people should aim for blood levels of 50 nanomoles per litre (nmol/L).
However, according to the Endocrine Society's guidelines:
- people with levels under 50 nmol/L are "vitamin-D deficient"
- those with levels between 50 nmol/L and 72.5 nmol/L are "insufficient"
The society's guidelines also offer an 'ideal' level of 100–150 nmol/L which would require 1,500–2,000 IU daily. It advises physicians to monitor vitamin-D levels in healthy people.
Quest Lab already began to implement these deficiency and insufficiency standards over the IOM's. Many physicians are expected to follow suit.
References:
The vitamin D-lemma. 6 July 2011 | Nature 475, 23-25 (2011) | doi:10.1038/475023a
Image source: Wikipedia, public domain.
Comments from Google+:
Neil Mehta - This sounds like deja vu' all over again. How many times have we been down this path? vitamin C, Vitamin E, Carotenes....
Common themes:
The myth of natural products: "it is a natural product so it can't cause harm can it?" Thus if a little bit of it is good, more must be better.
The research problem: "It is over the counter and present in foods so very difficult to determine how much someone is actually taking"
Huge confounder of observational studies: "People who take supplements, other "health products" are different from those who don't.
Posted at Clinical Cases and Images. Stay updated and subscribe, follow us on Twitter and connect on Facebook.
Neighborhood Determinants of Quality of Life – street lighting, sidewalks, trees, absence of air or noise pollution
This paper analyzed quality of life in Uruguay. Differences in overall happiness can be explained by access to public goods.
Neighborhood Determinants of Quality of Life included:
- access to electricity, running water, sewage system, drainage, waste disposal system
- street lighting
- sidewalks in good condition
- trees in the street - "forest bathing" (exposure to parks and forests) may increase immunity
- absence of air or noise pollution
Don't forget that happy people are 22% less likely to develop heart disease.
Based on research, Mike Cadogan summarized happiness in just 4 ideas - repeat every morning: "I'm happy, I'm hopeful about the future, I enjoy life, and I feel I'm just as good as other people."
References:
Neighborhood Determinants of Quality of Life. Néstor Gandelman, Giorgina Piani and Zuleika Ferre. Journal of Happiness Studies, 2011.
Image source: OpenClipArt.org, public domain.
Posted at Clinical Cases and Images. Stay updated and subscribe, follow us on Twitter and connect on Facebook.
Secure web messaging between patients and doctors: Not well received
Although e-mail may be an efficient clinician-patient communication tool, standard e-mail is not adequately secure to meet Health Insurance Portability and Accountability Act (HIPAA) guidelines. For this reason, firewall-secured electronic messaging systems have been developed for use in health care.
The Kryptiq messaging system was implemented at an academic center and messages were monitored continuously and tracked.
In the 8 months after implementation, only 5 messages were initiated by patients in contrast to 2,363 phone calls.
Patients/families expressed strong interest in e-mailing but secure Web messaging was:
- less convenient than using the phone
- too technically cumbersome
- lacked a personal touch
- only by a handful of patients
One pediatrician on Twitter wants a simpler solution:
@Doctor_V (Bryan Vartabedian): Gimme an integrated, secure Tw like tool for doc to doc/pt comm - part of record.
Comments from Twitter:
@davisliumd: No, Kaiser's data different: Use of Health Information Technology Leads to Improved Care Quality
@yejnes: My patients like it!
References:
Secure Web Messaging in a Pediatric Chronic Care Clinic: A Slow Takeoff of "Kids' Airmail". PEDIATRICS Vol. 127 No. 2 February 2011, pp. e406-e413 (doi:10.1542/peds.2010-1086)
Image source: Wikipedia, public domain.
Posted at Clinical Cases and Images. Stay updated and subscribe, follow us on Twitter and connect on Facebook.
Rapid analysis of melting point trends and models using Google Apps Scripts
I recently reported on how Google Apps Scripts can be used to facilitate the recording and calculations associated with a chemistry laboratory notebook. (also see resource page)
I will demonstrate here how these scripts can be used to rapidly discover trends in the melting points of analogs for the curation of data and the evaluation of models. The two melting point services that Andrew Lang created under the gONS menu were used to keep track of the measured and predicted melting points for all reactants and product as part of a "dashboard view" of the reaction being performed.
For looking at melting point trends, the following template sheet can be used.
For reasons explained previously, the template sheet has no active scripts in the page (except for the images). These are just the values generated from running the scripts corresponding to the column headings on the common names. In order to use for another series of compounds just make a copy of the entire Google Spreadsheet (File->Make a Copy) then enter the new list and pick the desired script to run from the menus. Once the values are computed remember to copy and paste as values.
It is important to understand that our melting point service is not a "trusted source" - it simply reports the average of all recorded data sources, ignoring values marked as DONOUSE. That means that not all data points are equal and it is up to the user to determine a threshold of some type to decide how to use a particular data point.
In this investigation, I have marked in green averaged experimental values where at least 3 different values are clustered within a few degrees. A link in column H is automatically generated from the CSID to provide a very convenient way to evaluate the data sources. For example the link for methanol has 3 very close but different melting point values: -98 C, -97.6 C and -97.53 C. The -98 C value is repeated 7 times because this resulted from the automatic merging of several Open Collections.
In general we don't manually add values that are identical from different sources because it is likely that these all originate from the same source. We have to make that assumption because proper data provenance is usually lacking in chemical information sources today. A Google search will often return the same one or two melting points from dozens of sites, which may turn out to be an outlier when compared with other independent sources. (CAS numbers are generated in the template sheet because they are useful for searching Google for melting points - for example see here for methanol)
In another scenario where there are 3 or more different but close values and a few clear marked outliers, I considered these averages as having passed my threshold and colored these green as well. A good example is ethanol, which I have previously used to illustrate our curation method.
It turns out that for the series of n-alcohols from methanol to 1-decanol, I was able to mark in green every experimental melting point average, making the confidence level of the following plot about as high as it can get from current chemical information sources.
It is particularly gratifying to note that the predicted melting points based on Andrew Lang's random forest Model002 perform very well here, even predicting a melting point minimum at 3 carbons. Note that this model is Open Source and uses Open Descriptors derived from the CDK. It does not yet include the results of our most recent curation efforts. Any new models incorporating improved datasets will be listed here.
Extending the analysis to n-alkyl carboxylic acids from formic acid to decanoic acid provides the following plot, with the same confidence for the experimental averages.
For this series, the random forest model not only predicts that the lowest melting point is for the 5 carbon analog but it also appears to take the shape of a zig-zag pattern, especially for the first 6 acids. Since this alternating pattern has been attributed to the way that carboxylic acid dimer bilayers pack in 3D (Bond2004), it is hard to imagine how simple 2D descriptors from the CDK can predict this. We will have to investigate this in more detail.
More generally, molecular symmetry can greatly affect the melting point via the way that crystals pack in 3D (see Carnelley's Rule, Brown2000). At some point we would like to incorporate this factor in our models. The current model should not be able to make predictions based on symmetry or stereochemistry.
We can also explore the melting point patterns of cyclic systems. Going from cyc
lopropane to cyclohexane there is a large jump from a 5 to a 6 membered ring and this is roughly reflected in the model:
Cycloalkanones behave similarly to cycloalkanes, showing a jump from 5 to 6 membered rings which agrees well with the model going from cyclobutanone to cyclohexanone:
However, in going from methylcylopropane to methylcyclohexane, the model diverges substantially from experimental results. It does start to get harder to find corroborating melting points and only 2 values can be found for methylcyclobutane.
Going from cyclopropanecarboxylic acid to cyclohexanecarboxylic acid shows a U-type pattern and is not well matched by the model. However, there is additional uncertainty about the melting point of cyclopentanecarboxylic acid.
For the series from cyclopropylamine to cyclohexylamine, there initially appears to be a significant mismatch between the model and experiment. However, because we have retained the provenance information in the spreadsheet it becomes clear that the cyclobutylamine number (in the orange square below) comes from a single source. There is actually a good match between the other 3 values. However, as demonstrated here, there has not been enough information on when the model is reliable to assign the source of the discrepancy at this point.
These examples show that provenance information is a critical dimension in the analysis of trends in melting point data. The Google Apps Scripts and associated Google Spreadsheet template presented here offer a quick and convenient way to provide access to both averaged values and a way of assessing confidence in an averaged value. Performing these tasks manually is generally too time-consuming to encourage researchers to follow such a practice. This is perhaps the reason that the current peer-review process accepts a single "trusted source" in analyses of this kind, even though such a practice inevitably leads to mis-interpretations and errors that cascade through the scientific literature.
Metamorphosis
Me&Edward is a 23 year old French photographer. He says his interests shifted from being a cook to “cooking with body parts, light, composition, and flesh.” The above photos are from the series “Metamorphosis.” Me&Edward defines the project as, “a concept about the unlimited transformations of human body. Just like a chameleon, it’s fitting, just like a virus, it’s mutating, just like a personality, it’s changing. Something new is about to birth, a metamorphosis, an organic complexity.”
I love the images because they look very real, as if these are the subjects’ actual bodies. They are eerie, but hard to look away from.
You can see more from the series in progress on Me&Edward’s flickr.
[via Change the Thought and Get Inspired Magazine]
Velo Cerebrum
VELO CEREBRUM – Holbrooks from F5 on Vimeo.
This trippy video, directed by Holbrooks and produced by Blacklist, was created for the Happy F5
RE:PLAY Film Festival which seeks to bring together those that are breaking ground and shaping new standards in media and design.
From the creators of the video:
“We wanted to take a dry look at the subject of happiness. To strip down the aesthetics of a smile, literally tearing skin from flesh, flesh from bone, bone cracking away. We wanted to expose the brain and let it reveal the spirituality and enigma of happiness. Of a simple action that makes this person happy in a way that they’d find hard to describe.”
[Spotted by Jenny]
Maurice Mbikayi
"Antisocial network I", 2010, computer keyboard and resin, 15 x 20 x 25cm
"Antisocial network II", 2010, computer keyboard and resin, 15 x 25cm
"Measuring the impact", 2010, PC keyboard, tape measures and USB cable on paper, 30 x 35cm
In a day when skull made out of objects are starting to feel a bit overplayed, Cape Town-based multi-disciplinary artist, Maurice Mbikayi, uses his skulls to make a sociocultural statement. Maurice identifies himself as a cultural activist interested in identity, origin and space, specifically how technology affects the diverse African populations. His talents span sculpture, performance art, installation art, photography, and mixed-media.
From Maurice’s artist statement:
Proceeding by collecting hardware remnants of this rapidly developing technology and other found objects and incorporating them into my work. The resultant mixed media drawings and sculptures ask questions such as to whom such technological resources are made available and at what or whose expense? What are the consequences impacting on our people and environment?
[Spotted by SARO via Juxtapoz]
Carnovsky
This piece is part of the amazing installation, RGB, by Carnovsky, the collaboration of Francesco Rugi & Silvia Quintanilla.
RGB is a work about the exploration of the “surface’s deepness”.
RGB designs create surfaces that mutate and interact with different chromatic stimulus.
RGB’s technique consists in the overlapping of three different images, each one in a primary color. The resulting images from this three level’s superimposition are unexpected and disorienting. The colors mix up, the lines and shapes entwine becoming oneiric and not completely clear. Through a colored filter (a light or a transparent material) it is possible to see clearly the layers in which the image is composed. The filter’s colors are red, green and blue, each one of them serves to reveal one of the three layers.
I seriously wish I could have experienced this in person.
[via Illusion Scene 360]
