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Commemorating the discovery of DNA fingerprinting

Some time ago, I did a post about fingerprinting and personal identification. Now while fingerprinting has been around for more than 150 years, a new breakthrough in personal identification happened much more recently – on this day in 1984, DNA fingerprinting was discovered in Leicester, England.

The man who discovered this revolutionary new technique, was Sir Alex Jeffreys of the University of Leicester. He was the first to realised that each person’s DNA has a unique pattern, almost like a bar code, and that this could be used as a biological identification method. The technique has, over the past 25+ years, proved an invaluable tool in forensics, crime investigations and identification of genetic relationships.

Geneticist studying a DNA profile.
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Of course no technique is perfect, and in the case of DNA fingerprinting there are also rare occasions where the technique cannot be used. Identical twins, for example, have matching DNA, and so their DNA fingerprints are the same.  A much rarer, and much stranger, occurrence is when a single person has more than one DNA fingerprint.

Strange as this may seem, having a single person with two distinct genetic identities is possible. This condition is known as chimerism, named after the chimera, a mythological creature with features from more than one distinct animal, for example a lion’s head and a serpent’s tail.

A human chimera is formed during pregnancy. Normally the male gamete (sperm) fuses with the female gamete (ova) to form a zygote, the cell that becomes the embryo. This embryo has a new genetic identity, formed from a unique combination of the DNA of the mother and the father. On rare occasions, two male gametes will fuse with two female gametes, to form two zygotes which develop into two (non-identical) twin embryos. These embryos will each have a different, unique new DNA fingerprint, inherited from the father and mother.

In extremely rare cases, these two embryos can fuse, growing into a single child, but formed from four gametes, and thus having two distinct sets of DNA. The chimera child can grow up without anyone ever knowing about his double identity, but may in fact have different organs or body parts that have completely different genetic fingerprints. Even when a DNA identity test is done on a chimera, DNA will usually only be taken from a single source, such as a blood sample or cheek swab, and the second identity may never be known.

Chimerism may, in rare occasions, visibly manifest itself, for example with people having both male and female reproductive organs, or two different colour eyes. (However, different eye colours, or heterochromia, can have different causes, and is, as far as I know, not necessarily an indication of chimerism.)

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The most famous example of a chimera confounding DNA profiling came from a case in 2003, when a mother of three were told, after DNA tests were done on her and her three children, that two of her three sons were not hers, even though she maintained that she had conceived them with her husband, and delivered them naturally.

After more extensive testing, it was discovered that she was a chimera, and that the two sons thought not to be hers did in fact match her ‘second identity’.

Definitely a case where truth is, in fact, stranger than fiction.

Daffodil Day and the ongoing fight against cancer

It’s Daffodil Day today, August 31st. Well, it’s Daffodil Day in New Zealand, to be exact – Australian Daffodil Day happened on the 24th of this month already. The US, bless them, seem to have a whole bunch of different Daffodil Days across different states. (With Daffodils being a spring flower, it obviously makes sense that most US Daffodil Days happen earlier in the year, around February, and not August/September, as it does down here in the South.)

Daffodil Day is all about cancer – raising awareness of the disease, raising funds for cancer related research, and creating a support network for individuals suffering from the disease.

The reason why the daffodil flower is used internationally by Cancer Societies as the global symbol of hope for people living with cancer, is that it is one of the first, and one of the strongest, flowers of spring, and as such is a symbol for hope and renewal, new life, new beginnings and new possibilities.
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Cancer is an incredibly pervasive, prevalent disease – here in New Zealand it is the leading cause of death in the country –  and I’m sure there are very few people who are not in some way fairly directly affected by it. My dad died of cancer in his liver and colon; my mother in law is a breast-cancer survivor; just about everyone I know has someone close to them who has either died from, or is living with, the disease.

In a nutshell, cancer occurs when cells in the body accumulate genetic changes (due to various factors), resulting in a loss of growth control. Normal cells grow, divide and die in an orderly manner, in response to signals from the body and the environment. When cells become cancerous, however, they fail to respond to the normal signals, and start growing and dividing in an uncontrolled manner. These out-of-control cells can spread through the body via the bloodstream or lymph vessels (a process called metastasis) and continue to grow and replace normal tissue. It is the fact that it’s the body’s own cells that go crazy and effectively turn against their host, that makes it such a complex disease to treat.

As mentioned, one of the critical focus areas of Daffodil Day is raising money to support research into finding cures for the disease.

Over the years, literally billions of dollars have been spent on cancer research, and it’s quite a sobering thought when you realise that, in spite of all this, the death rate from the disease has changed little over the past 50 or so years. As new therapies are developed, cancer also adapts and evolves, finding new ways to kill.

Now this does not mean all is in vain – millions of people have been saved from the therapies that have been developed. All it means is that there is no room for complacency, and new and more effective cancer therapies are continually needed to stay ahead of, or at least keep up with, the disease.

In my job as a science photographer, I interact with a wide range of research and technology organisations, and one of the most inspiring of these is the Malaghan Institute of Medical Research – New Zealand’s leading medical research institute, and a registered charity based in Wellington, NZ. The reason I mention this fact is that one of their main fields of research is cancer (they also research cures for asthma, arthritis, multiple sclerosis and infectious diseases) and they are one of the organisations supported through the proceeds of fundraising events like Daffodil Day.

One of the main fields of cancer research that the Malaghan Institute focuses on is Immunotherapy, which basically involves using the immune system and it’s unique properties to complement existing cancer treatments. As they explain, “Immune cells are specific and have the capacity to discriminate between normal and cancer cells, they have powerful effector capacity and can recruit inflammatory cells to destroy neoplastic tissue, and they can migrate to different tissues and eliminate residual metastatic disease.” So, similar techniques to those used in helping the immune system recognise and fight contagious diseases (such as vaccination, etc), can also be used to help the immune system recognise cancer cells and to strengthen their ability to destroy them.

Another more recent research subject at the Institute is cancer stem cell research. Cancer stem cells are cancer’s evil root – these tumor initiating cells are highly resistant to drug and radiation treatment – and the focus of the research is on finding safe and effective ways to eradicate them.

Researchers at the Malaghan Institute of Medical Research are conducting research into Immunotherapy, unleashing the full cancer-fighting potential of the immune systems of cancer patients to fight the disease.
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Organisations like the Malaghan Institute, and many others like them across the world, are doing incredible work to address the continually evolving threat of cancer, and really need all the support they can get. It’s a scary, scary topic, and it’s good to know there are talented, committed scientists and researchers out there facing the challenge head on.

Chasing away the winter blues with a roisterous “Hoodie-Hoo!”

Today us folk in the Southern Hemisphere get our turn to celebrate ‘Hoodie-Hoo Day’ (about 6 months after the Northern Hemisphere version). So what is Hoodie-Hoo? Well, in a nutshell it’s the day where we should all go outside at noon, drink in the (hopefully) warming weather and at the top of our lungs yell “Hoodie-Hoo!!” to chase away the winter blues and to celebrate the fact that spring is on it’s way.

According to some sources, you can celebrate the day in even more authentic style by donning a funny or unusual hat while performing your celebratory shouting.

‘Southern Hemisphere Hoodie-Hoo Day’, and its companion ‘Northern Hemisphere Hoodie-Hoo-Day’ are two of 80-odd holidays dreamt up by the folks over at Wellcat.com, a herbal company who felt the world simply didn’t have enough holidays, and came up with a bunch of new ones under the moniker of “Wellcat Holidays”.

The reason I decided to feature this day is that it got me thinking about this amazing time of year, when the seasons almost imperceptibly start changing. It is more often than not still cold and miserable, but everyone knows it’s not quite winter anymore – animals stir from hibernation, trees start budding all over the place, flowers appear as if by magic and there really is a sense of anticipation in the air.

The fruit trees in our garden, including this plum, are all doing their blossomy version of the Hoodie-Hoo.
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Ever wondered how plants know spring is approaching? In a New Yorker article I found, Dr Susan Pell from the Brooklyn Botanical Garden explains things very nicely. According to Dr Pell, “Why and how plants flower when they do is something that has puzzled botanists for centuries. We’ve come a long way, but there is still quite a bit about the signalling details that we don’t know. There are many factors involved, but given the right growing conditions (soil nutrients, water and sun exposure), day length and ambient temperature are the key factors.”

Various proteins in the plant (such as phytochrome and cryptochrome) can actually sense the relative lengths of the light and dark parts of the day. (This is an example of photoperiodism.) Furthermore plants also sense ambient temperature, with some plants requiring a cold snap before they will start flowering. Once the nights become short enough and the temperature reaches the right level, growth, and specifically flowering, is triggered in the plants. As far as temperature is concerned, plants tend to not be fooled by a single unexpected warm day, but rather react to a sustained warm period. If such a period occurs too early, it can trick the plant into flowering earlier than it is supposed to, which could expose the fresh growth to frost damage in a subsequent cold spell. The plant’s light and dark sensing abilities should keep this from happening, but particularly in cities with lots of artificial light, these sensors may be too confused to function correctly.

Dr Pell furthermore says, “The hypothetical protein that signals plants to bloom once the ideal conditions have arrived has long been called ‘florigen‘, but it is uncertain whether or not it has actually been identified.” Claims to its identification has been made in various research papers, but no conclusive evidence have been presented.

I sometimes wonder whether us humans also have our own florigen-like trigger telling us that spring is on its way? One definitely gets a sense that the seasons are changing – this sense of new life stirring – even before you see spring flowers appearing. The world not only looks different (subtle changes in the colours of the sky and the land), but it also feels different – an early morning jog is still nippy as hell, but the cold somehow starts to feel refreshing, rather than depressing.

I don’t know – perhaps its merely the fact that my diary tells me spring is on its way that makes me see and feel things.  Whatever the case may be, and whether it’s florigen induced or not, I am definitely going to let rip with a loud ‘Hoodie-Hoo’ holler today!

(And to all my Northern Hemisphere friends – hang in there, and mark 20 February in next year’s diary. It may still be six months off, but your chance to ‘Hoodie-Hoo!’ is coming – better start practicing!)

Celebrating creepy-crawlies on Spider-Man Day

I’m not sure how official it is, but according to various sources on the web, today is Spider-Man Day. So, while I haven’t been able to find anything else of much interest, let’s just go with that, shall we?

(Source: Marvel Comics)

Spider-Man is undoubtably one of the best loved superheroes ever dreamt up by Marvel Comics. This has a lot to do with the fact that the person behind the suit, Peter Parker, was pitched as a bit of a nerd, an outsider with whom many young readers could easily relate.

 

But beyond this human touch, Spider-Man’s lasting fascination must have a lot to do with our fascination of the creepy crawly that gave the superhero his powers. Spiders (order Araneae), the eight legged, predatory anthropods that evokes equal measures of fascination and fear in the human race. More than 40 000 species of spiders have been identified, and they are one of the most widely distributed groups of organisms, having established themselves in an extremely diverse range of habitats.

Spiders – fascinating and just a little bit scary.
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Indeed there is much to find fascinating, and scary, in spiders, from miniscule, deadly poisonous species to huge monsters that can take on birds and lizards. Spiders use various techniques to hunt and capture their prey – trapping them in sticky webs, camouflaging themselves to avoid detection, running down their prey, and more. Some hunting spiders even show signs of intelligence in their ability to develop new hunting tactics.

Spider venom, fatal to their prey and in many cases also deadly to humans, have been researched for use in medicine and natural insecticides.

And then there’s the incredible spider silk – the sticky stuff excreted by spiders that exceed almost all synthetic materials in terms of lightness, strength and elasticity, and without doubt the most fascinating ‘superpower’ in Spider-Man’s arsenal. Spider silk is composed mainly of protein. It is initially a liquid, and it hardens as a result of being drawn out, changing it’s internal protein structure. It’s tensile strength is similar to nylon and cellulose, but it’s way more elastic. Spiders use their silk for numerous applications, from webs to capture prey, to parachutes to carry them on the slightest breeze.

Fascinating creatures indeed, and definitely worthy of your admiration, whether you’re a Spider-Man fan or not!

Celebrating our fingerprints – hands off, criminals!

Today is a celebration only for those of us without criminal intentions – we commemorate the day in 1858 that fingerprints were used for the first time for identification purposes.

The little ridges on our skin that constitute our fingerprints. Not only are their patterns unique to each individual, but they also help with our sense of touch, and enable us to grip smooth and slippery surfaces.
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The story goes that Sir Wiliam James Herschel, British Chief Magistrate of the Hooghly district in Jungipoor, India, began using fingerprints in contracts with the native people. On this day in 1858 he decided, on a whim, to get a local business man to make a hand-print on a contract, to “frighten [him] out of all thought of repudiating his signature.” This made a big impression on the signee, and Herschel ended up using the hand-print technique on all his contracts. In later contracts he scaled down the process, taking only the prints of the index and middle fingers. People who had their hand-prints captured on contracts, believed that it somehow bound them tighter to the contract than simply placing their signatures on the paper. So, interestingly, the first use of fingerprints were motivated more by superstition than by science.

Since these early, superstitious beginnings, things have of course changed a lot, with fingerprint-recognition developing into a precise science, and with personal identification technologies becoming the stuff science fiction fantasies are made of, including DNA profiling, also known as genetic fingerprinting..

A fingerprint, in the most basic sense, is an impression left by the friction ridges (raised portions of the epidermis) on the finger. These ridges exist on the skin to assist in our sense of touch – they help, for example, to amplify the sensation of a finger brushing against some surface, transmitting the sensory signals to the nerves. The friction ridges also assist us in gripping smooth and slippery surfaces.

The discovery that the little patterns on our fingers are unique, and that the prints we leave at a scene can identify us after the fact, was not good news to criminals, who were suddenly faced with the extra hassle of wiping off weapons, wearing gloves and more, to avoid identification. I guess some career criminals would give anything to contract the medical condition known as adermatoglyphia. People suffering from this condition have completely smooth fingertips, palms, toes and soles, without suffering any other known problems. While this must be a terrible affliction if you want to go through certain legal procedures that require fingerprint identification, it does equip you well for a life of crime. I am sure that law enforcers the world over would be happy to know that only four families suffering from  this condition have so far been identified.

For the rest of us, I guess staying on the right side of the law remains the best option. And at least our fingerprints make us better equipped to pick up smooth, slippery objects like an ice cold beer!

Fifty Shades of Red

Do you know why your blood is red? It’s thanks to the red blood pigment, haemin, which is one of the components of haemoglobin.

And why do I know this? Well, because I’ve been reading up on Hans Fischer, the German biochemist who was born on this day in 1881, and who was awarded the Nobel Prize for Chemistry in 1930, primarily for his work on the structure and synthesis of the blood pigment haemin. In 1929, Fischer succeeded in synthesising haemin, the deep red, oxygen-carrying, non-protein, ferrous component of haemoglobin, that gives blood its red colour.

It’s elementary, my dear Watson – this is definitely not alien blood.
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Oxygen-rich blood (such as arterial blood and capillary blood) is bright red, as the oxygen intensifies the colour in the haemin. When oxygen is extracted from the blood it turns a darker shade of red – this can be seen in the veins, and in the blood collected during blood donation. The colour of blood can also be an indicator for certain medical conditions. Both carbon monoxide poisoning and cyanide poisoning result in bright red blood, as it inhibits the body’s ability to extract and utilise the oxygen in the blood. On the other hand, severe deoxygenation (which can be caused by respiratory diseases, cardiac disorders, hypothermia, drug overdose or exposure to high altitude) results in a condition called cyanosis, where the blood darkens to such an extent that it gets an almost purple-blueish hue, resulting in the skin turning a blue colour.

While the blood of humans and all vertebrates is always a shade of red (containing haemin), it’s interesting to note that it is, in a strange way, surprisingly close to being green! In addition to his work on blood pigmentation, Thomas Fischer also studied the components of the pigments in leaves. He found that, like the haemin in blood, the chlorophyll in leaves is a porphyrin, and that haemin and chlorophyll share a very similar structure, with only subtle differences.

All of this talk of blood, and red and green pigmentation, conjure scenes of science fiction in my mind – if haemin (that makes blood red), is so similar to chlorophyll (that makes leaves green), perhaps the idea of green-blooded aliens is not such a stretch. It makes scientific sense, right?

Anyway, let me rather stop before I get too carried away. Enjoy the day, and keep an eye out for those little green men! 🙂

Celebrating robots and robotics – useful and seriously cool!

Today we celebrate the birthday of Joseph F. Engelberger (born in New York City, July 26, 1925), physicist, engineer and entrepreneur, and the man often called the “Father of Robotics”.

Engelberger, together with inventor George Devol, was responsible for the development of the first industrial robot in the US, in the late 1950’s. The robot, called the Unimate, worked on a General Motors assembly line at the Inland Fisher Guide Plant in New Jersey in 1961. It picked up die castings from an assembly line and welded these to the auto bodies – a potentially dangerous task for humans.

The Unimate was inducted into the Robot Hall of Fame in 2003.

Engelberger and Devol also started Unimation, the world’s first robot manufacturing company. Engelberger was a strong advocate for robotic technology beyond the manufacturing plant, and promoted the use of robotics in fields as diverse as health care and space exploration.

Robots – not only are they useful in fields as diverse as manufacturing, transport, space exploration and surgery, but they make seriously cool toys!
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The field of robotics deal with automated machines that can take the place of humans, performing various activities in potentially hazardous or tedious processes in fields ranging from manufacturing to research to exploration. While Engelberger was responsible for the first industrial robot, the robotics concept dates back much further, to the start of the 20th century. The word “robot” was first coined by the Czech writer Karel Čapek in 1920.  In 1942, science fiction writer Isaac Asimov published his “Three Laws of Robotics”, which constituted the first use of the term “robotics”.

A lot of effort and investment has gone into research and development in the field of human-machine interaction, covering areas such as voice synthesis, gesture recognition, and facial expressions.

I’m not sure if it’s thanks to the fact that robots are so popular in science fiction – often depicted as an intelligent, cunning and efficient super-race – but I find it difficult not to feel awed, and even a little threatened, when facing one of these amazing inventions.

Dōmo arigatō, Mr. Roboto!

Celebrating the birth of the first ‘test tube’ baby

Today we celebrate a special birthday – Louise Joy Brown, the world’s first ‘test tube’ baby, was born on this day back in 1978 in Oldham, England.

Louise was conceived in a petri dish (so technically she was a ‘petri dish baby’ rather than a ‘test tube baby’), via the process of in vitro fertilisation (IVF). Her parents, Lesley and John Brown, had been trying to conceive for nine years, but faced complications of blocked fallopian tubes.

The process was a great success, and amazingly, by the time Louise turned 21 in 1999, more than 300 000 babies had been born using similar IVF techniques.

Louise’s IVF was performed by Dr Robert Edwards of Cambridge, who had previously successfully performed similar procedures with animals. He was assisted by gynaecologist Patrick Steptoe, who was already the Browns’ doctor. Edwards was awarded the 2010 Nobel Prize in Medicine for his contributions in the field of reproductive medicine.

The Latin term ‘in vitro’ is used for any biological process that occurs outside the organism it would normally be occurring in.
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In vitro fertilisation is a procedure where an egg cell gets fertilised by sperm outside the body. After successful fertilisation, the fertilised egg (zygote) gets transferred to the patient’s uterus in order to continue developing like a normal pregnancy.

The term in vitro (Latin: ‘in glass’) came about to describe a procedure that specifically occurred in a glass container (such as a test tube or petri dish), but its use has been extended to refer to any biological procedure that occurs outside the organism it would normally be occurring in.

Louise Brown got married in 2004, and her own son, conceived naturally, was born in late 2006. Happy 34th birthday, Louise!

Celebrating the invention of foam rubber

Today in 1929, British scientist EA Murphy, who worked at the Dunlop Latex Development Laboratories in Birmingham, must have been a little bored, or mischievous, because he decided to whip up some latex rubber with a kitchen mixer.  As is often the case with such seemingly arbitrary actions, he ended up inventing a product that, up to this day, has a huge impact in all our lives – foam rubber. It is said that Murphy’s colleagues were initially unimpressed, but this soon changed when they caught on to the amazing cushioning and shape retaining properties of this new invention, and it wasn’t long before foam rubber was used in motorcycle and car seats, mattresses and much more.

In its natural form, latex is a milky white liquid tapped from the trunks of rubber trees. This pure latex gets whipped up with water to create a thick froth. The froth is sometimes exaggerated using CO2 gas. Once frothy, the mixture is heated to the point of vulcanization (about 240°F) which results in the formation of long molecular chains with strong crosslinked bonds, giving the resultant foam rubber its ability to recover its shape after compression.

Close-up view of frothy foam rubber.
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While the shape retention characteristics of foam rubber make it a very versatile substance, it does have some limitations. When it gets exposed to very high temperatures it will melt, and if its frozen it can shatter.

Now researchers at the National Institute of Advanced Industrial Science and Technology in Japan, have come up with a new carbon-based nanotube rubber that has even better shape memory than foam rubber, and that can withstand extreme temperatures without any negative effects.

The unique features of this new super-rubber make it ideally suited for use in extreme conditions like spacecraft and car shock absorbers. Incorporating it into clothing also means that you can have a truly non-wrinkle shirt. Perhaps most exciting is the electricity conducting abilities of the carbon nanotubes, which means that, if its used in shoes or shock absorbers, the material could theoretically harvest and store the electricity generated.

While high costs mean the large-scale application of these super-rubbers are still some way off, one can just imagine it becoming as pervasive as foam rubber over the next decades.

Love your camera on Camera Day

Me and my camera; my camera and me.

The photographer and his camera – where does one start and the other end? How much of what you see in an image is down to the brilliance of the photographer, and how much can be attributed to the technical abilities of his photographic tools?

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I am, generally speaking, a supporter of the school of thinking that a great artist will produce great art irrespective of his tools. I have seen photos taken on mobile phone cameras that are significant artistic achievements, and there are movements in photography who go to great lengths to show how great art can be produced by technically “bad” equipment. The Lomographic Society International, for example, owns galleries, etc, showcasing photographs taken with very low-tech LOMO cameras. LOMO, a former Russian state-owned camera manufacturer, produced 35mm compact cameras that have become iconic for producing unique, sometimes blurry images, at times with light leakage, and various other “faults”.

On the other hand, particularly in technical fields of photography, the camera plays a critical role in enabling the photographer – think about fields like macro photography, for example. In some ways the camera also dictates the photographers’ approach to the subject. For instance, the time and effort required to set up a large format view camera to photograph a landscape, will almost by default result in a different stylistic approach to the subject compared to, say, a photo snapped with a mobile phone.

Given my current context (photographing science, technology and industry) my “weapon of choice” is my Nikon D3 DSLR, with a range of lenses for different applications, and I have to admit I love this bulky machine – its reassuring weight, ever willing, ever ready for anything I may throw at it.

That is not to say I am not eagerly eyeing the D4 and even the D800, not to mention the wonderful, iconic Leica M9. And don’t even get me started on some of the glorious medium format cameras out there, just waiting for me to take them in my arms!

On the other end of the technology scale, I’ve recently started playing around with pinhole photography again – in a sense this still remains to me the most magical, wonderfully rewarding field of photography. But more on that in a future post.

Whether you photograph with a mobile phone or a Hasselblad, today is Camera Day – the day to show some special appreciation for your camera, and to take it out and capture the world around you. Wherever you may be – have fun.