This is not an article about the song made famous by the late (great) Don Ho. This is about a breakthrough in the understanding of how micrometer-sized bubbles can be stabilized for long periods of time. This can influence the taste, smell, and consistency of consumer products including food and cosmetics.

In two-phase systems, which can include air (as bubbles) suspended within a liquid, the structures of the dispersed (bubbles) and continuous (liquid) phases play a critical role in determining the properties of the material. There is also the function of time in that the microstructure of the dispersed phase continuously evolves toward a state of lower energy by minimizing the surface area between the two phases (referred to as the interfacial area). In the long term, this time evolution diminishes the usefulness of two-phase systems. Emilie Dressaire, Rodney Bee, David Bell, Alex Lips, and Howard Stone have devised a way to stabilize a two-phase system for time periods of a year or longer.

Embryologic development is a dynamic process that has been previously studied by examining static (usually chemically-fixed) specimens at different time periods and then extrapolating results by assembling a series of static images. Recently, Amy McMahon, Willy Supatto, Scott Fraser, and Angelike Stathopoulos have developed new methods to look at developmental migration patterns in real time. They used an optimized imaging approach and quantitative methods to analyze a two hour period during which gastrulation occurred in the embryos of fruitflies (Drosophila). Specifically, they characterized the complex interactions between cells of the ectoderm and mesoderm by tracking the movements of over 1,500 cells, which involved the analysis of over 100,000 cell positions for each embryo!

The most widely accepted model of learning at the level of the cell involves associative synaptic plasticity in brain neurons that include cortical pyramidal cells (PC). To oversimplify, for a neuron to “learn” from information coming into it, electrical events need to occur in a fairly precise pattern throughout the cell membrane.

It is well known that females of some insects mate with more than one male before the ova are fertilized. The post-copulatory behavior of the sperm has been studied for decades, but until now there has not been a method to definitively determine the “ownership” of sperm within the female genital tract. In a very clever study, Mollie Manier, John Belote, Kirstin Berben, David Novikov, Will Stuart, and Scott Pitnick offer an answer to this dilemma .

All cells have the ability to synthesize and secrete proteins. Although many details of this process are well-known, Martin Kampmann and Günter Blobel recently highlighted two “landmark papers” that used cryo-electron microscopy (cryoEM) to obtain information at subnanometer resolution, which provided direct visualization of nascent polypeptide chains in the tunnel with ribosomes . It is known that the signal peptide (the first few amino acids on the amino terminal that do not become part of the final polypeptide) emerges from a ribosome and engages the signal recognition particle (SRP) in the cytoplasm, and this complex is directed to the SRP receptor on the endoplasmic reticulum (ER). The SRP is released, the signal peptide enters the protein-conducting channel (PCC), and the nascent polypeptide chain (that will become the protein) enters the lumen of the ER.

Fossil arachnids—especially those dating from the Carboniferous period, 360–299 million years ago—are often found in mines or quarries within concretions of siderite (FeCO3). Most of the methods to study these fossils are either destructive or damaging to the specimens and are limited in their resolution, thereby limiting the information that can be derived from the fossil. In an elegant study, Russell Garwood, Jason Dunlop, and Mark Sutton have demonstrated that X-ray micro-tomography (XMT) can reveal hitherto unseen details in such fossils without damaging the specimens.

Some of the receptors on the surface of cardiac muscle cells (cardiomyocytes) mediate the response of these cells to catecholamines by causing the production of the common second messenger cyclic adenosine monophosphate (cAMP). An example of such receptors are the β1- and β2-adrenergic receptors (βARs) that are heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors. Selective stimulation of these two receptor subtypes leads to distinct physiological and pathophysiological responses, but their precise location on the surface of cardiomyocytes has not been correlated with these responses. In an ingenious combination of techniques, Viacheslav Nikolaev, Alexey Moshkov, Alexander Lyon, Michele Miragoli, Pavel Novak, Helen Paur, Martin Lohse, Yuri Korchev, Sian Harding, and Julia Gorelik have mapped the function of these receptors for the first time.

Motile cilia are organelles that contain amazing molecular machines that bend each cilium in a rhythmic and coordinated movement. This allows a liquid film, perhaps with particles embedded within, to move in a specific direction. The classic example is the cilia of the respiratory passages that move a layer of debris-carrying mucus out of the lungs. When this mechanism is not working properly, recurrent pulmonary infections result. The classic example of this is immotile cilia syndrome that results in chronic bronchitis and related problems. However, no sensory function has been assigned to these classic motile cilia until now (although nodal cilia have both mechanical activity and sensory functions). Alok Shah, Yehuda Ben-Shahar, Thomas Moninger, Joel Kline, and Michael Welsh have demonstrated sensory receptors on motile cilia for the first time.

Light optical imaging techniques that don't require labels are attractive for human studies because they are not toxic nor do they perturb the system being studied. Whereas there are several methods available to provide microscopic imaging below the surface of a tissue, they each suffer from limitations, such as low spatiotemporal resolution and a limited number of molecular signatures that can be imaged. Raman spectroscopy offers label-free contrast for major chemical species in tissue, such as water, lipids, DNA, and proteins based on vibrational spectra at light optical wavelengths. However, the Raman signal is very weak, which makes it difficult to image a sample with good temporal resolution. The recent development of stimulated Raman scattering (SRS) microscopy can overcome these limitations as demonstrated by the elegant studies of Brian Saar, Christian Freudiger, Jay Reichman, Michael Stanley, Gary Holton, and Sunney Xie. Saar et al. improved the optics and electronics for the acquisition of the backscattered signal of SRS. In SRS microscopy, the sample is excited by two lasers at different frequencies. When the difference in frequency matches a molecular vibration in the sample, the intensities of the probes change in a predictable manner. These intensity changes are small, but Saar et al. developed a new method to detect them. They chopped one of the laser beams at high frequency (MHz) and detected the intensity change in the other beam, which offered superior sensitivity. The key component was a custom-made all-analog lock-in amplifier with a very short (about 100 ns) response time. The laser probe wavelengths were tuned to match a vibrational frequency of interest and raster-scanned across the sample. Frequencies were tuned to detect CH2 stretching (primarily for lipids), OH stretching (primarily water), and CH3 stretching (primarily proteins) vibrations. Imaging of water is of particular interest in studying the transport of water-soluble compounds such as drugs.

In 1969 a meteorite exploded over Pueblito de Allende in northern Mexico. Many of the fragments were recovered and have provided a wealth of information about the chemical composition of our early universe. Most recently, Chi Ma, Oliver Tschauner, John Beckett, George Rossman, and Wenjun Liu have reported a new mineral in one of these meteorite fragments. Ma et al. named this new form of titanium oxide “panguite” for Pan Gu, the giant in Chinese mythology who, in the beginning, created the world by separating the heaven and earth from chaos. This is an allusion to this ultra-refractory mineral, stable at high temperatures and in extreme environments, being among the first solid materials in our solar system.

One of the largest freshwater fish (2 to 2.5 meters long, over 150 kg) lives in the Amazonian rivers and lakes. It is well known that these waters are populated with piranhas that swarm and devour almost anything that moves. The lungfish Arapaima gigas coexists with piranhas by virtue of an armor-like plating of scales. Y.S. Lin, C.T. Wei, E.A. Olevsky, and Marc Meyers examined the microscopic structure and mechanical properties of these scales to discover what provided this protection.

In the animal kingdom, eyes come in a relatively small variety of functional forms. When a new optical system is found, it usually is a variation of a known form. It is very rare to discover a novel form of an eye. Such a sensational discovery has been made by Annette Stowasser, Alexandra Rapaport, John Layne, Randy Morgan, and Elke Buschbeck. Using two different experimental approaches, they demonstrated an eye with a truly bifocal lens, something that has only been suggested for certain long-extinct trilobites

The ability to determine the age of commercially important aquatic species is important to managing their populations. Whereas the age of most aquatic animals can be found by counting annual growth bands in hard structures, such as the fish otoliths (stone-like structures in the ear that are important for balance and orientation) and bivalves' shells, a technique to directly and accurately age individual crustaceans does not exist. At least it didn't until the recent study by Raouf Kilada, Bernard Sainte-Marie, Rémy Rochette, Neill Davis, Caroline Vanier, and Steven Campana. This is a bit of surprise because nothing equivalent to the hard structures of fish or bivalves had been found, or even expected to exist, in crustaceans. This is simply because this group of animals grow by molting or by shedding off their skins. Not only does molting frequency vary considerably among species of crustaceans, but molting individuals are assumed to lose and replace all calcified structures, including the cuticle (exoskeleton), that might record annual growth.

Fluorescence microscopy can be used to study certain single molecules in solution or attached to a surface. Two conflicting challenges to overcome are: (1) to image freely moving molecules for long times and (2) to image immobilized single molecules when there is a highly fluorescent background. The fact that these two goals are inversely related is illustrated by epifluorescence, which is good for observing freely diffusing molecules but poor for detecting single molecules, whereas the reverse is true for zero-mode waveguides. Plus, these and other techniques require elaborate (read: expensive) equipment with computerized controls. Sabrina Leslie, Alexander Fields, and Adam Cohen have developed an ingenious (relatively) simple technique that can image freely moving single molecules.

There are certainly “big movies” such as Gone with the Wind and “small movies” such as Beasts of the Southern Wild, but Andreas Heinrich, Chris Lutz, Susanne Baumann, and Ileana Rau at IBM literally have set a new Guinness World Record™ for the smallest movie ever made. Heinrich et al. used a remotely operated two-ton scanning tunneling microscope to manipulate carbon monoxide molecules into a pattern, then capture the image (at a magnification of about 100,000,000×!), then move a few atoms and capture another image, and so on. This was done at 268 degrees below zero Celsius. Then approximately 250 images were assembled into a stop-action movie accompanied by cute music that lasts a little over a minute. The “boy” appears to be composed of 88 individual atoms. He bounces a “ball” (a single atom) off a wall in a minuscule game of “handatom,” which is reminiscent of the early video game “Pong.” Then he bounces on a tiny trampoline. The movie concludes with a tasteful mention of IBM.

Actin filament assembly occurs in all eukaryotic cells and involves a delicate balance between factors that promote assembly and factors that inhibit assembly. Filament assembly begins with a process of nucleation and then proceeds via elongation. Filament assembly in vivo requires nucleation and elongation factors to overcome barriers that could either bind actin monomers to inhibit nucleation or “cap” the ends of elongating filaments. The formation of most cellular actin structures depends on two or more such factors, which may interact directly. The interaction between two factors that initiate nucleation and promote assembly has recently been demonstrated by Dennis Breitsprecher, Richa Jaiswal, Jeffrey Bombardier, Christopher Gould, Jeff Gelles, and Bruce Goode. Interestingly, the model of these factors in action (Figure 1) resembles a rocket launcher!