Trend: Does cell biology need physicists? This paragraph gives you an idea of what he is talking about in terms of a cross disciplinary approach to biology:
For a cell with a fairly small genome, such as the yeast Saccharomyces cerevisiae, which can produce between 104 and 105 proteins, the number of possible protein interactions is 105–107 . Even if we consider a single cellular function (for instance, the ability of a eukaryotic cell to move along a substrate) the chemical reaction network that describes this behavior appears incomprehensible (Fig. 1). The hope of systems biology is to use a higher level approach to understand these systems, to analyze the reaction networks at a more functional level and provide a framework for assembling models of biological pathways from systematic measurements . Absent from this discussion is any mention of the physics involved in cellular processes. It is possible that the physics that cells must deal with is slave to the reactions; i.e., the protein levels and kinetics of the biochemical reactions determine the behavior of the system, and any physical processes that a cell must accomplish are purely consequences of the biochemistry. Or, could it be that cellular biology cannot be fully understood without physics?
Thus far most biological systems even at the ‘simple’ cellular level defy the kind of reductionism that physicist tend to like. Like probably is not the best term. The laws of physic thus far tend to produce universal theorems. Objects fall in a vacuum in a certain predictable way. Evolution makes it clear that biological systems can find several ways to find solutions, all of which work relatively well. The brain is wired a certain way, but if damaged – not too severely, the brain will attempt to establish new pathways that will accomplish as much as the old pathways as possible. If you want an object launched into space to make similar on the fly adjustment – you have to program in the possible obstacles to reaching its target and program in the actions it should take, and in what sequence. Wound healing brings up an example of the kind of ‘thinking’ biological systems do in response to damage,
When an organism is wounded, epithelial cells crawl to fill in the wounded area. An experimental method for exploring this process is to grow a monolayer of epithelial cells on a substrate and then to “wound” the layer using a scalpel or some other object to scrape away a region of cells. Pascal Silberzan and co-workers have shown that the motion of the cells during wound healing is not trivial and involves long-range order and complex cellular flows . Based on these observations and an analogy between crawling cells and the collective swimming of bacteria, we proposed a model that captures many features that are observed in wound healing assays. We suggest that two dominant physical attributes are responsible for most of the processes involved in wound healing: (i) the dipole nature of the stress distribution of a crawling cell and (ii) cell-cell adhesions. This model absorbs all of the complex biochemistry and actin dynamics inside a cell into two parameters that describe the stress that a cell exerts on its surroundings, and cell-cell adhesion dynamics can be shown to lead to visco-elastic couplings between cells [Fig. 3 (b)]. Therefore, where many groups have focused extensively on the complex biochemical interactions inside the cell, at a functional level (i.e., healing of a wound), many of the molecular details may only act to regulate a few bulk physical parameters.
A regular body cell does not have a brain. How does it know it is injured. How do other cells know to be activated to repair injured cells. The brain senses injuries and could activate the cells or some cells involved. All without your conscious involvement in the process. Unlike decided what kind of cheese you want on your sandwich or what color shirt to buy. The genes in the cell could be programmed – through millions of years of evolution – to act when certain electro-chemical signals are initiated ( described in the excerpt). Though once again without anything that we call conscious action by the brain. It seems like a large part of what it takes to maintain whatever makes an organism alive takes place on partly a conscious level – avoiding predators, while another, without conscious input, maintains all the tiny components and processes required to have consciousness.
Despite what Dave Weigel says, the fates seem determined to drag the Ann Romney/Hilary Rosen/war on women/war on moms debate into the weekend, so I guess I might as well, too. One response to the War on Moms claims—well-made by Salon’s Irin Carmon here—is that, Mommy Wars rhetoric, aside, the Republican policy agenda actually offers bubkes in the way of practical support to moms (and dads, who, let’s not forget, are parents too) struggling to raise their kids up right. I’d concur and add:
One of the distasteful things about the tendency to label all sorts of debates or initiatives as “wars” is that in real wars, people die. But the reality is that a shockingly high number of American moms are dying for preventable reasons. The U.S. Maternal Mortality Ratio (the number of maternal deaths per 100,000 live births) is shockingly high, well above the average for the developed world, and higher than virtually all of Western Europe as well as some countries in Asia and the Middle East. Even more troubling, U.S. maternal mortality has increased in the last two decades, and is now more than twice as high as it was in the late 1980s. The Affordable Care Act included provisions designed to help stop this scary trend—not just by expanding health care access (many maternal deaths could be prevented with proper care)—but also through the Maternal, Infant and Early Childhood Home Visiting program, created as part of ACA, which provides nurses and social workers to work with high-risk moms, starting before they give birth, to help them have healthy pregnancies and deliveries and support their babies’ health and development after birth.The program is modeled after programs, such as the Nurse Family Partnership that have a strong track record of improving maternal and child outcomes, preventing abuse and neglect, increasing fathers’ involvement in their kids’ lives, improving kids’ school performance, reducing crime, and saving the taxpayers a boatload of money over the long term.
I remember trying ti learn history in 4th grade. I read the assigned material and made good grades, but I wondered about what practical use it was. I’ll admit that part of what kept me motivated at the time was an over active imagination. Native Americans, settlers, sea voyages were all grist for the adventure story I pieced together in my head. I did eventually see the practical applications. These people’s mistakes and triumphs were lessons I could learn from by proxy. I did not have to have rickets to experience the pain. I did not have to be cheated out of my property to understand the virtue of fairness and empathy. Other people had already lived harsh examples of those experiences. All I had to do was sacrifice a few hours of TV to learn from them. Conservatives seem to be largely the kids who let it all go in one ear and out the other. For them unplanned pregnancies stared with the invention of glossy magazines, or TV, or R-rated movies. In complete denial about human history, including Mary Magdalen, apparently conservatives think that unplanned pregnancies, teen pregnancies, pregnancies complicated by disease or other medical considerations are all the result of door busting get it while you can social safety net programs – and the availability of condom and oral contraceptives. If we did away with food stamps, Medicaid, condoms and the pill, people would – for the very first time in the history of humanity – stop having babies except under the perfect sociological circumstances. That would be a nice fantasy come true. Though fantasy is the key word. It is possible with a combination of education and some enlightened public policy to greatly reduce those alleged society destroying unplanned pregnancies. Only conservatives are also against education and enlightened public policy.
As Boys Grow: Sex Education in Schools for Teenagers (1/2) (1957)