Climate change
On track to throw the world completely off track
I took the weekend off last week, so naturally a paper landed in the Proceedings of the National Academy of Sciences that generated a considerable response. So, though it’s now a whole week old, I’m bouncing back to this article from an international team … with appropriately global impact.
We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a “Hothouse Earth” pathway even as human emissions are reduced. Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene.
One of the first things that deniers of anthropic global warming throw out there is that “climate is always changing” and “Earth used to be warmer.” Both of these things are true. Neither of them has a bit to do with climate change caused by human activities. After all, if you find someone standing next to a clear-cut acre with a chainsaw in hand, you can infer what happened without invoking “trees fall in the forest.” It has been warmer in the past. At least two times in the last 100 million years, it’s been considerably warmer, and life on Earth has survived.
But we weren’t here. If it happens again, we won’t survive. Not as a culture, and likely not as a species. A temperature change even approaching those past levels would utterly shatter the ability of Earth to provide for billions of humans. An ecosystem completely dominated by people and a handful of species used for feeding people, where other animals and plants have already been forced into the margins, is already fragile. Under such a hammer blow, it would take millions of years to recover its diversity if such a change takes place. This isn’t the disaster we usually think of when we contemplate climate change. This is an apocalyptic take, the end of humanity through heath death, a very near worst case scenario.
So … where do we stand versus this dark possibility? There’s a significant risk that we’re not already on the path to this cataclysmic result, but further down the road than we believe.
Medicine and Health
Identifying spinal signal carrier offers hope to arthritis sufferers
Chronic arthritis is a very real physical affliction affecting the joints. But the amount of pain that people suffer from the disease isn’t entirely, or even mostly determined by the amount of damage those joints have endured.
Arthritis is the most common cause of physical disability, affecting more than 50 million adults and 300,000 children in the United States (Arthritis Foundation). In these individuals, chronic joint pain is a major clinical concern. Although peripheral pathology is a diagnostic feature of arthritis, pain correlates poorly with the extent of joint pathology, and therapies that suppress joint inflammation are often inadequate for pain control. This apparent disconnect suggests that peripheral inflammation alone does not entirely account for the pain in arthritic joints.
Evidence shows that pain is “generated and amplified” by the pain-sensing system within the brain and spinal cord, particularly in an area called the “spinal dorsal horn.” Researchers from the University of Calgary have identified the pathway though which pain from chronic arthritis is relayed to this region of the spine. Increased pain seems to be tired to the pannexin-1 ion channel, a channel also implicated in pain from neuropathy. In a mouse study, blocking receptors in this channel eliminated joint pain. This gives researchers a good target in looking for drugs that selectively address arthritis pain while having a limited affect on other systems.
The search for a universal flu vaccine.
Every year, epidemiologists look at trends around the world and try to predict which variants of the influenza virus are likely to be most widespread during the coming year. Then they formulate a vaccine, which is replicated hundreds of millions of times, and distributed around the planet to help prevent people from acquiring a disease that is often debilitating, and sometimes deadly. Only, researchers don’t always do the greatest job of zeroing in the rising threat. Sometimes, and 2018 was one of those years, they get surprised, and the vaccine is much less effective because the particular variants that become widespread aren’t closely related to any in that cycle’s cocktail.
But what if they didn’t have to play this prediction game? What if they could just give a flu vaccine that was good against … flu?
Influenza is an inveterate shape-shifter. Regions of its outer proteins can mutate as it replicates, allowing it to avoid immune detection. When infections with new flu strains occur later in life, the immune system will mount a response based on that first encounter, reacting strongly to recognized regions of the virus, but not to any that have changed. Immune cells can’t tailor any novel antibodies that could help.
The article details research to look at how the immune system ‘imprints’ on the flu virus, and how that information could be used to create a universal vaccine.
Climate Change
Global warming gives plants a broader growing range, but increases the impact of cold snaps.
Climate change is requiring agronomists to constantly redraw the lines on those “growing zones.” Plants that once were restricted to more tropical climes are now spreading — both by human intent and mechanisms of their own — into formerly subtropical areas. Similar things are happening across the different climate ranges, and the changes are most extreme near the poles, where plants are spreading into areas whose ecosystems had previously been extremely limited. But even with the average global temperature going up, occasional cold snaps still occur. a team lead by researchers from Harvard looked at the changes in temperature versus the differences in length of day as plants move into colder areas, and found that temperature dominated what grew where.
And when new plants move in, these more cold-sensitive invaders can be the first to fall. Which can lead to a kind of perverse result.
Failure to cue to photoperiod resulted in precocious green-up and a premature loss of frost hardiness, which suggests that vulnerability to spring frost damage will increase in a warmer world.
Warmer world … more frost damage. Of course, if it gets warm enough, this problem will be “solved.” In the worst way.
Climate change brings more Arctic spiders … and slows decay
With the high Arctic warming, the first thought might be that this would increase the rate of decay for organic material. After all, more bacteria, more fungi, but … there’s another factor.
Predators can disproportionately impact the structure and function of ecosystems relative to their biomass. These effects may be exacerbated under warming in ecosystems like the Arctic, where the number and diversity of predators are low and small shifts in community interactions can alter carbon cycle feedbacks.
The predators under study in this case are wolf spiders, also known as “those big ones that show up in your laundry room and make you drop a sock behind the dryer.” Wolf spiders are “a dominant tundra predator.” But the numbers of the spiders had a complex interaction with fungus, fungus-eating insects called springtails, nitrogen in spider-waste, nitrogen in the soil, and temperature. It all comes together to suggest that more spiders is a good thing in cold conditions, but more spiders becomes an issue in warm conditions. And, as with so many stories, suggests that there are complex interactions going on whose complete nature we’re only starting to see.
Robotics
In case you need a hand … and a hand … and another hand.
Scientists at the Advanced Telecommunications Research Institute have successfully created a non-invasive brain-machine interface that allows test subjects to fluidly control a third arm. Obviously, this has applications for those who have lost a limb due to accident or disease, but … the test participants were able to control this arm in addition to two working arms. The interface not only proved capable of supporting the fine level of control without needing a physical connection directly to the brain, but the brain proved capable of managing an extra limb and integrating the movement of that limb with existing limbs.
This outcome opens possibilities to explore future human body augmentation applications for healthy people that not only enhance their capability to perform a particular task but also extend their physical capabilities to perform multiple tasks simultaneously.
Doc Ock, please call line one.
Biology
CRISPR give a … crisper view of vertebrate development.
Using CRISPR to plant “genetic bar codes” allowed researchers at Harvard Medical School to track development of a single cell into a mouse, and follow that course form one cell to a billion cells while keeping track of each step along the way.
Over the years, biologists have used a variety of methods to track an organism’s development cell by cell, such as labelling them with dyes. But these tools are unable to follow cells through many divisions, let alone over an organism’s entire life. In the past two years, however, CRISPR–Cas9 genome editing has emerged as a potent tool for monitoring development in exquisite detail.
The tools allowed researchers to see which early cells formed the heart, liver, muscles, bones … everything. And they could see how those divisions and differentiations played out over days and weeks of development.
Tracing cell lineages in mice could be a useful tool for understanding the cellular basis for human disease, says McKenna. Cancer researchers, for example, could breed the barcode strain with their own mouse models of cancer to examine in detail how the disease disrupts cell division. “I think we’re a little way from that,” he says, “but this is a big step forward.”
Anthropology
Using fire to herd buffalo among Native Americans
The image of Native Americans that first comes to mind for many people, both in the US and around the world, is of Plains Indians, hunting buffalo from horseback. But native horses died out in the Americas at around the same time as humans showed up. It wasn’t until the Spanish brought horses back to America that Americans first got in the saddle, and once the people of the plains were up and riding, some of the hunting techniques involved didn’t use bow and arrow, so much as flint and fire.
Native American and First Nations hunters built and used landscape features on these grasslands to harvest bison en masse. Charcoal layers associated with drivelines indicate that fire was an important part of these hunting practices. Furthermore, correlation of dated fire deposits and climate records indicate that ancient bison hunters burned in response to favorable climate conditions. This study indicates that climate and human activities are not mutually exclusive factors in fire histories; even relatively small groups of hunter-gatherers can enhance climate impacts.
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