Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: biological – Page 175

A group of researchers at Sandia National Laboratories have developed a tool that can cross-train standard convolutional neural networks (CNN) to a spiking neural model that can be used on neuromorphic processors. The researchers claim that the conversion will enable deep learning applications to take advantage of the much better energy efficiency of neuromorphic hardware, which are designed to mimic the way the biological neurons work.

The tool, known as Whetstone, works by adjusting artificial neuron behavior during the training phase to only activate when it reaches an appropriate threshold. As a result, neuron activation become a binary choice – either it spikes or it doesn’t. By doing so, Whetstone converts an artificial neural network into a spiking neural network. The tool does this by using an incremental “sharpening process” (hence Whetstone) through each network layer until the activation becomes discrete.

According to Whetstone researcher Brad Aimone, this discrete activation greatly minimizes communication costs between the layers, and thus energy consumption, but with only minimal loss of accuracy. “We continue to be impressed that without dramatically changing what the networks look like, we can get very close to a standard neural net [in accuracy],” he says. “We’re usually within a percent or so on performance.”

Read more

As living organisms eat, grow, and self-regenerate, all the while they are slowly dying. Chemically speaking, this is because life is thermodynamically unstable, while its ultimate waste products are in a state of thermal equilibrium. It’s somewhat of a morbid thought, but it’s also one of the characteristics that is common to all forms of life.

Now in a new study, have created a self-replicator that self-assembles while simultaneously being destroyed. The synthetic system may help researchers better understand what separates biological matter from simpler chemical matter, and also how to create synthetic life in the lab.

The researchers, Ignacio Colomer, Sarah Morrow, and Stephen P. Fletcher, at the University of Oxford, have published a paper on the self-replicator in a recent issue of Nature Communications.

Read more

To answer the iconic question “Are We Alone?”, scientists around the world are also attempting to understand the origin of life. There are many pieces to the puzzle of how life began and many ways to put them together into a big picture. Some of the pieces are firmly established by the laws of chemistry and physics. Others are conjectures about what Earth was like four billion years ago, based on extrapolations of what we know from observing Earth today. However, there are still major gaps in our knowledge and these are necessarily filled in by best guesses.

We invited talented scientists to discuss their different opinions about the origin of life and the site of life’s origin. Most of them will agree that liquid water was necessary, but if we had a time machine and went back in time, would we find life first in a hydrothermal submarine setting in sea water or a fresh water site associated with emerging land masses?

Biologist David Deamer, a Research Professor of Biomolecular Engineering at the University of California, Santa Cruz, and multi-disciplinary scientist Bruce Damer, Associate Researcher in the Department of Biomolecular Engineering at UC Santa Cruz, will describe their most recent work, which infers that hydrothermal pools are the most plausible site for the origin of life. Both biologists have been collaborating since 2016 on a full conception of the Terrestrial Origin of Life Hypothesis.

Lynn Rothschild, Senior Scientist at NASA’s Ames Research Center and Adjunct Professor of Molecular Biology, Cell Biology, and Biochemistry at Brown University, who is an astrobiologist/ synthetic biologist specializing in molecular approaches to evolution, particularly in microbes and the application of synthetic biology to NASA’s missions, will provide an evolutionary biologist’s perspective on the subject.

Continue reading “Where is the Origin of Life on Earth?” | >

“We looked at a group of tiny, green bacteria called Prochlorococcus which is the most abundant photosynthetic organism on Earth, with a global population of around three octillion (~1027) individuals,” says Sasha.

Ten per cent of the oxygen we breathe comes from just one kind of bacteria in the ocean. Now laboratory tests have shown that these bacteria are susceptible to plastic pollution, according to a study published in Communications Biology.

“We found that exposure to chemicals leaching from interfered with the growth, photosynthesis and oxygen production of Prochlorococcus, the ocean’s most abundant photosynthetic bacteria,” says lead author and Macquarie University researcher Dr. Sasha Tetu.

“Now we’d like to explore if is having the same impact on these microbes in the ocean.”

Continue reading “It’s not just fish, plastic pollution harms the bacteria that help us breathe” | >

It’s very easy to forget that complex life on Earth almost missed the boat entirely. As the Sun’s luminosity gradually increases, the oceans will boil away, and the planet will no longer be in the habitable zone for life as we know it. Okay, we likely have a billion years before this happens—by which point our species will probably have destroyed itself or moved away from Earth—but Earth itself is 4.5 billion years old or so, and eukaryotic life only started to diversify 800 million or so years ago, at the end of the “boring billion.”

In other words, life seems to have arisen around four billion years ago, shortly after Earth formed, but then a few billion years passed before anything complex evolved. Another few hundred million years of bacteria, algae, and microbes sliding around in the anoxic sludge of the boring billion, and intelligent life might never have evolved at all.

Unraveling the geologic mysteries of the boring billion, and why it ended when it did, is a complex scientific question. Different parts of the earth system, including plate tectonics, the atmosphere, and the biosphere of simple lichens and cyanobacteria interacted to eventually produce the conditions for life to diversify, flourish, and grow more complex. But it is generally accepted that simple cyanobacteria (single-celled organisms that can produce oxygen through photosynthesis) were key players in providing Earth’s atmosphere and oceans with oxygen, which then allowed complex life to flourish.

Read more