chrisdellavedova.com

My friend and fellow scientist Jason has been hassling me to write a post about the recent stem cell breakthroughs that have been all over the news for the last week. Two research groups, one led by Shinya Yamanaka at Kyoto University and the other by James Thomson at the University of Wisconsin, have published papers in Cell and Science respectively describing the induction of stem cells from somatic cells. I’ve hesitated to write about this because it has been getting lots of coverage in the More on Stem Cells: Clean Your Own Side of the Street

This week in Science Tuesday we’ll focus on research with implications on the beginnings and the ends of human life. First, a study from Yale looking at the morality of infants and second, a paper from the Howard Hughes Medical Institute in Seattle suggesting that a certain class of anti-depressant can increase the lifespan of nematodes. More on Science Tuesday: Baby Morality and Worm Longevity

When things get nasty in a particular environment, organisms that call it home have got to come up with ways to cope. Animals are mobile and tend to migrate to an environment where the proverbial grass is greener. However, if you are a sedentary organism – a plant for example – you must find other ways of managing. This week a study by two American ecologists suggests that some plants get maternal help in coping with their environment.

In general, plants have little choice in terms of where they live. Seeds tend to germinate where they fall and even though many plants use elaborate schemes to insure that their seeds are spread great distances there is no way to guarantee that they More on Science Tuesday: Mother Knows Best?

Methicillin-resistant Staphylococcus aureus (MRSA) now causes more deaths per year in the U.S. than AIDS. MRSA’s tendency to resist treatment by common antibiotics has predictably earned it the nickname “Superbug” in the lay press. But beyond the press hype is the foundation of a true epidemic. Staphylococcus species of bacteria are fairly benign and are commonly found on the skin of healthy people. It only becomes a problem when it enters the bloodstream – through an open cut for example – at which point it can cause an infection. These infections are usually minor More on Science Tuesday: The Superbug’s Superpower

There was an article that came out yesterday in BBC News citing a study that claims that breast fed children with a certain allele (variant) of a gene involved in fatty acid metabolism scored seven points higher in IQ tests than formula fed babies. This is one of those studies that I’ve suddenly become interested in since becoming a father. However, whenever I see an article like this in the general press I am skeptical. Often mainstream journalists miss subtleties of scientific papers that cast doubt on the claims that are made. And as a scientist, I know that we often bury doubts or inconsistencies in the research deep in the paper so as to make them less obvious to the reader. I often goto the original research in cases like these to see what’s really going on.

I want to keep this article as a short post, so read the BBC article for the details. But, I would like to give kudos to the BBC writer of this article – he or she has gotten this one mostly right. But there are a number of issues that he or she has missed in the original paper. The biggest problem that I have is that it is not clear from this study, how long the children were breastfed. The study groups are two large groups from New Zealand and Britain in which parents were surveyed when the kids were age two to three as to whether they were breastfed or not. However, there is no indication as to how long the children were breastfed. A second issue that I have is that it is true that in the groups that were studied, the allele of the FADS2 gene that is responsive to breast milk is present in 90% of those tested. However, these groups are almost exclusively of western European ancestry. In the New Zealand study, aboriginal people are even eliminated from the study to avoid potential problems (this is buried in Materials and Methods). There is no indication of how common this allele is outside the British Isles. Third, the scientists have eliminated any variation due to social class, the intelligence of the mother and differences in birth weight. However, variation due to the fathers’ intelligence is not eliminated. Finally, these two groups were studied in the early 70’s and mid-90’s respectively – prior to supplementation of formula with some of the fatty acids that are thought to be important to the IQ boost. Most formulas now include these components.

All that being said, I think that their conclusions are generally valid and breastfeeding certainly is not going to hurt. Personally, I do not have strong feelings about breastfeeding. Sinead is breastfeeding Zach and we’ve got our own personal reasons for making that choice. The current social climate in Britain is a little bit heavy-handed about breastfeeding. So much so that in some cases women may be made to feel as if they’re hurting their children by bottle feeding. I think that this kind of evangelism about breast feeding can be a bit much, particularly if you can not breast feed for whatever reason. It’s important to remember that this as with any scientific study does not prove anything, it only provides more data to support a hypothesis. As the authors of the PNAS study say themselves, “although evidence [for this hypothesis] is mounting, it has not yet been proven.”

Image Credits:

Breastfeeding photo

“I love you more than I did the week before
I discovered alcohol
O Alcohol, would you please forgive me?
For while I cannot love myself
I’ll use something else…”

-Barenaked Ladies – “Alcohol”

Alcoholism is a disease with major world health implications. There are over 15 million people in the U.S. suffering from alcoholism resulting in over 100,000 deaths a year and health care costs approaching 200 billion dollars. In Britain there are an estimated 36,000 hospital More on Science Tuesday: Drunk Flies Tell Tall Tales About Alcoholism

Neanderthals are our hominid relatives with whom we shared the Mediterranean region for several thousand years before began to be supplanted by modern man around 45,000 years ago and became extinct shortly thereafter. There are a number of questions regarding their fate, the biggest being why modern humans were ultimately more successful than neanderthals. Some scientist believe that it was modern man’s ability to use spoken communication that allowed us to outcompete (or kill off) the Neanderthals. Another interesting hypothesis, that makes research into the genetic nature of Neanderthals quite current, is that climate change was a major factor in their extinction. But beyond this topical coincidence, any evolutionary comparison that we can make More on Science Tuesday: Chatty Redheads or Dirty Hands?

“There’s no map
To human behaviour
They’re terribly moody
Then all of a sudden turn happy…”

Bjork – “Human Behavior”

Evolution of species is driven by selective forces, usually changes in the environment that require a species to adapt or to die out. For example, a plant may be living happily in a marshy environment, perfectly adapted to a wet climate. Then a drought hits their environment. Year after year more of these plants dies out because they can not cope with a dry climate. However, if one member of this population develops a genetic mutation that confers some sort of drought tolerance and is able to breed then the offspring of this plant More on Science Tuesday: Breeding a Better Human

[tag]Breast cancer[/tag] is the leading cause of [tag]cancer[/tag] death among women world wide. Like all types of cancer it is notoriously difficult to cure because it is not a simple disease – like a bacterial infection – rather it is a complex failure in cell regulation. This failure results in a single rogue cell that grows aggressively and can become invasive – attacking and destroying surrounding tissues – or [tag]metastatic[/tag] – spreading to other parts of the body. There are a number of steps involved in a benign [tag]tumor[/tag] cell becoming metastatic. First the tumor invades surrounding tissue, then can enter the circulatory system and travel through the body, followed by invasion of a More on Science Tuesday: Micro Metastasizer

My training as a scientist is in [tag]plant genetics[/tag], but my [tag]Science[/tag] Tuesday posts to date have all been medical in nature. This is because science that has a direct impact on people is “sexier”. This week, however, I’ve started feeling some guilt about spurning my botanical roots (pun intended) in favor of the glamour of research into human disease. So let’s see if I can sexy up some plant science.

It was a good week for plant molecular genetics. A report in Science from Dan [tag]Klessig[/tag]’s laboratory at Cornell University elucidated elegantly how plants defend themselves. One of the tough things about being a plant is that you are generally pretty tied down to your birthplace and thus at the mercy of whatever gets thrown at you. Plants aren’t stupid, however, and they have developed numerous ways to protect themselves from More on Science Tuesday: Sexy Plants