Diatoms are a major group of typically unicellular algae, and are one of the most common varieties of phytoplankton. Unique to diatoms, their cells are encased in a cell wall of silica (silicon dioxide), which is responsible for their crystalline appearance. Diatoms are autotrophic, meaning they derive their nutrition from their surroundings by means of photosynthesis or chemosynthesis. This places them in the role of producers in the food chain.
Blood Falls, a Natural Time Capsule Containing a Unique Ecosystem
By Atlas Obscura
This five-story, blood-red “waterfall” pours ever so slowly out of the Taylor Glacier in Antarctica’s McMurdo Dry Valley. Geologists first discovered the frozen waterfall in 1911, and believed the red color came from algae. Its true nature turned out to be more spectacular.
Roughly two million years ago, a small body of water containing an ancient community of microbes was sealed beneath the surface of the Taylor Glacier. Trapped below a thick layer of ice, the microbes have remained isolated inside a natural time capsule, in a place with no light, oxygen, or heat.
The trapped lake has very high salinity and is rich in iron, which gives the seepage its red color. A fissure in the glacier allows the microbial subglacial lake to flow out, forming the falls without contaminating the ecosystem within.
Symphylans, also known as garden centipedes or glasshouse symphylans, are soil-dwelling arthropods of the class Symphyla in the subphylum Myriapoda. Symphylans resemble centipedes, but are smaller and translucent. They can move rapidly through the pores between soil particles, and are typically found from the surface down to a depth of about 50 cm. They consume decaying vegetation.
Juveniles have six pairs of legs, but, over a lifetime of several years, add an additional pair at each moult so that the adult instar has twelve pairs of legs. Lacking eyes, their long antennae serve as sense organs. They have several features linking them to early insects, such as a labium (fused second maxillae), an identical number of head segments and certain features of their legs.
Each of these diatom cells is only about 50 microns long, but they aggregate in chains that can be shaped like stars, or helix shaped, like this one. Diatoms are very abundant and an incredibly important component of marine and aquatic foodwebs. They have very distinctive shapes, but they are not all the same.
These mites are distributed worldwide as commensals of humans. It is unknown from what region they originated, they have been associated with humans throughout their evolutionary history. They inhabit the hair follicles of most if not all humans. They infest areas around the nose, in the ear canals, and around the eyelids…
Biomimetic Nanosponges Absorb Toxins released by Bacterial Infections and Venom
provided by Univ. of Cal.-SD
Engineers at the University of California, San Diego have invented a “nanosponge” capable of safely removing a broad class of dangerous toxins from the bloodstream – including toxins produced by MRSA, E. coli, poisonous snakes and bees. These nanosponges, which thus far have been studied in mice, can neutralize “pore-forming toxins,” which destroy cells by poking holes in their cell membranes. Unlike other anti-toxin platforms that need to be custom synthesized for individual toxin type, the nanosponges can absorb different pore-forming toxins regardless of their molecular structures. In a study against alpha-haemolysin toxin from MRSA, pre-innoculation with nanosponges enabled 89 percent of mice to survive lethal doses…
Scientists a step closer toward creating biofuels directly from atmospheric CO2
Researchers have taken a step closer to using atmospheric carbon dioxide as a biofuel, potentially helping mitigate climate change while at the same time meeting rising energy demand, according to a study published in the Proceedings of the National Academy of Sciences.
Scientists at the University of Georgia and the North Carolina State University are working with the bacteria Pyrococcus furiosus to convert CO2 into directly biofuels…
Each Tetrahymena has a gene for its own sex—or mating type—in its regular nucleus, but it also carries a second nucleus used only for reproduction. This “germline nucleus” contains incomplete versions of all seven mating type genes, which are cut and pasted together until one complete gene remains and the other six have been deleted…
The life of extremophiles: Surviving in hostile habitats
by Christopher Brooks/BBC Scotland
Beetles with antifreeze blood, ants that sprint on scorching sand and spiders that live high up Mount Everest.
These incredible creatures are the extremophiles: animals that survive some of the most inhospitable conditions on Earth, and sometimes even further.
Scientists are amazed by the survival abilities of this motley crew and are currently researching their peculiar adaptations to find out whether they can be transferred to our own species.
In northern Alaska, the red flat bark beetle (Cucujus clavipes) survives arctic conditions using a cocktail of internal chemicals.
The formation of ice crystals in internal fluids is the biggest threat to its survival, but the beetle produces antifreeze proteins that stop water molecules from grouping together.
They also fortify their blood with high concentrations of glycerol, which means that the water in their bodies will not form the ice crystals that would kill other species, even at much milder temperatures…
Volvox are green algae that inhabit a variety of freshwater habitats across the world.
These microscopic organisms form hollow, spherical colonies of thousands of cells. In some species, individual algae are connected by strands of cytoplasm, and there is division of labor between different groups of cells. Volvox and its relatives have therefore been used as model systems to study the evolution of multicellularity and cellular differentiation.
Like today’s insects and crustaceans, trilobites had compound eyes, with many different lenses focusing light onto clusters of sensory cells lying below them. The resulting image was put together a lot like a picture on your computer screen, with each lens producing one “pixel” of the whole. Because the lenses themselves were made of the mineral calcite, they often fossilized along with the rest of the trilobite’s tough exoskeleton. The sensory cells underneath the lenses, however, were ephemeral, and scientists had always assumed that they had decayed without a trace.
So imagine Brigitte Schoenemann’s surprise when she spotted fossilized versions of these delicate sensory cells while x-raying a long dead trilobite with a computed tomography (CT) scanner. “I expected that we would see [something] in the lens of trilobites, but then suddenly we saw structures of cells below the lens,” recalls Schoenemann, a physiologist at the University of Bonn and the University of Cologne, both in Germany.
Inspired, she applied to take more fossils to the European Synchrotron Radiation Facility in Grenoble, France, where she could use a particle accelerator’s high energy x-rays to peer deeper into the trilobites’ eyes. Now, she says, she’s created images of the extinct animal’s entire visual system, down to the level of fossilized individual cells…