Lifeboat Foundation

If two statisticians were to lose each other in an infinite forest, the first thing they would do is get drunk. That way, they would walk more or less randomly, which would give them the best chance of finding each other. However, the statisticians should stay sober if they want to pick mushrooms. Stumbling around drunk and without purpose would reduce the area of exploration, and make it more likely that the seekers would return to the same spot, where the mushrooms are already gone.

Such considerations belong to the statistical theory of “random walk” or “drunkard’s walk,” in which the future depends only on the present and not the past. Today, random walk is used to model share prices, molecular diffusion, neural activity, and population dynamics, among other processes. It is also thought to describe how “genetic drift” can result in a particular gene—say, for blue eye color—becoming prevalent in a population. Ironically, this theory, which ignores the past, has a rather rich history of its own. It is one of the many intellectual innovations dreamed up by Andrei Kolmogorov, a mathematician of startling breadth and ability who revolutionized the role of the unlikely in mathematics, while carefully negotiating the shifting probabilities of political and academic life in Soviet Russia.

Thoughts?

Wearable electronic devices are playing a rapidly expanding role in the acquisition of individuals’ health data for personalized medical interventions; however, wearables cannot yet directly program gene-based therapies because of the lack of a direct electrogenetic interface. Here we provide the missing link by developing an electrogenetic interface that we call direct current (DC)-actuated regulation technology (DART), which enables electrode-mediated, time-and voltage-dependent transgene expression in human cells using DC from batteries. DART utilizes a DC supply to generate non-toxic levels of reactive oxygen species that act via a biosensor to reversibly fine-tune synthetic promoters.

A paper published today in Nature Metabolism has described a method of genetically engineering cells to respond to electrical stimuli, allowing for on-demand gene expression.

Despite its futuristic outlook, this line of research is built upon previous work. The idea of an implantable gene switch to command cells in order to deliver valuable compounds into the human body is not new. The authors of this paper cite longstanding work showing that gene switches can be developed to respond to antibiotics [1] or other drugs, and the antibiotic doxycycline is used regularly for this purpose in mouse models. More recently, researchers have worked on cells that control their output based on green light [2], radio waves [3], or heat [4].

However, these mechanisms have their problems. A gene trigger that operates in response to a chemical compound requires that compound to have stable, controllable biological availability [5]. If it relies on any wavelength of electromagnetic radiation, that process may be triggered by mistake or require intense energy to function [3].

With the summer holiday season now in full swing, the blog will also swing into its annual August series. For most of the month, I will share with you just a small sampling of the colorful videos and snapshots of life captured in a select few of the hundreds of NIH-supported research labs around the country.

To get us started, let’s turn to the study of viruses. Researchers now can generate vast amounts of data relatively quickly on a virus of interest. But data are often displayed as numbers or two-dimensional digital images on a computer screen. For most virologists, it’s extremely helpful to see a virus and its data streaming in three dimensions. To do so, they turn to a technological tool that we all know so well: animation.

Continue reading “3D Animation Captures Viral Infection in Action” »

For over a century, biologists have had to contend with a complicated picture of genetics, which they’ve only recently begun to understand.

UCLA Health researchers have published the largest-ever study of families with at least two children with autism, uncovering new risk genes and providing new insights into how genetics influence whether someone develops autism spectrum disorder.

The new study, published July 28 in the Proceedings of the National Academy of Sciences, also provides genetic evidence that language delay and dysfunction should be reconsidered as a core component of autism.

Most genetic studies of autism have focused on families with one child affected by the neurodevelopmental disorder, sometimes excluding families with multiple affected children. As a result, few studies have examined the role of rare inherited variation or its interaction with the combined effect of multiple common genetic variations that contribute to the risk of developing autism.

Every person starts as just one fertilized egg. By adulthood, that single cell has turned into roughly 37 trillion cells, many of which keep dividing to create the same amount of fresh human cells every few months.

But those cells have a formidable challenge. The average dividing cell must copy — perfectly — 3.2 billion base pairs of DNA, about once every 24 hours. The cell’s replication machinery does an amazing job of this, copying genetic material at a lickety-split pace of some 50 base pairs per second.

Materials possessing both strength and lightness have the potential to enhance everything from automobiles to body armor. But usually, the two qualities are mutually exclusive. However, researchers at the University of Connecticut, along with their collaborators, have now crafted an incredibly strong yet lightweight material. Surprisingly, they achieved this using two unexpected building blocks: DNA

DNA, or deoxyribonucleic acid, is a molecule composed of two long strands of nucleotides that coil around each other to form a double helix. It is the hereditary material in humans and almost all other organisms that carries genetic instructions for development, functioning, growth, and reproduction. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA).

An expert on aging thinks humans could live to be 1,000 years old—with a few tweaks to our genetic “software”.