Tag: science

Mosquito Gene Drive

Engineered sterile male mosquitoes
Brought down mosquito population in a test run in small town by 85% in 4 months.

2016-02-17:

Obviously there are some risks here, but risks have to be weighed against benefits – if we don’t do it, mosquito-borne diseases keep killing 1M people each year.

2016-07-15:

Today, worldwide, 3000 people will die of mosquito borne illnesses. 3500 will die in auto accidents. I don’t have good numbers to scale the problem of hospital errors globally — but I’m guessing between 5000 and 20000 deaths a day. These problems are easy or at least easy-ish to fix. The medical profession can break the culture of “let’s wing it” and “who has time to wash their hands?” in hospitals. It is possible to get rid of the mosquitoes that carry malaria, dengue, zika and the rest. The technology to deliver self-driving cars is close.

There are loads more real problems that kill people in huge numbers that have easy-ish ways to fix that I can name. By contrast, the terrorist attack yesterday was a single, small incident. Terrorism kills very few people.

2016-10-06: Wow, awfully clever name.

Bad mosquitoes spread disease. Good mosquitoes can stop them. Debug is a group of scientists and engineers developing technology to raise and release sterile mosquitoes to eliminate the ones that carry disease.

2016-10-08: The anti-vaxxers found a new hobby.

If the Keys scuttle the project, it may go against broader public opinion. A national survey found that 78% supported using GMO mosquitoes to fight Zika. Last month a bipartisan group of 61 Florida state legislators issued a statement asking the FDA to use emergency powers to give them Oxitec right now. “What’s happened now is you have various mosquito districts saying, ‘Why can’t we use this technology?’ ” If the vote goes against Oxitec, “we would move the trial somewhere else. But obviously it would be more preferable and more convenient to do it where we planned to do it.”

2022-07-04: Changing host smell

Some diseases can change how their hosts smell. Certain viruses and microorganisms have evolved to use this to their advantage. For instance, plants that are infected with the Cucumber mosaic virus release a molecule that attracts aphids, which the virus uses as a vector to infect new plants. Parasites that cause malaria advertise their hosts to passing mosquitoes through changes in body odor. Mice infected with Zika or dengue produced 10x as much acetophenone as did healthy mice. Daubing healthy mice — and a few human volunteers — with acetophenone revealed that mosquitoes were drawn to the smell. Giving infected mice vitamin A, which is commonly used to treat skin conditions, helped to lower the amount of acetophenone the animals exuded, potentially providing a new way to control the spread of both diseases.

2022-11-26: Data from a new field trial

treated mosquito populations were suppressed by 88-96%. Male mosquitoes have short lifespans as it is—just seven to 10 days—and the self-limiting trait becomes less prevalent in each subsequent generation of males. Eventually, it fades within the gene pool. That means more releases are needed.

Negative temperatures

With positive temperatures, atoms more likely occupy low-energy states than high-energy states, a pattern known as Boltzmann distribution in physics. When an object is heated, its atoms can reach higher energy levels. At absolute 0, atoms would occupy the lowest energy state. At an infinite temperature, atoms would occupy all energy states. Negative temperatures then are the opposite of positive temperatures — atoms more likely occupy high-energy states than low-energy states. “The inverted Boltzmann distribution is the hallmark of negative absolute temperature, and this is what we have achieved. Yet the gas is not colder than 0 kelvin, but hotter. It is even hotter than at any positive temperature — the temperature scale simply does not end at infinity, but jumps to negative values instead.” Objects with negative temperatures behave in very odd ways. For instance, energy typically flows from objects with a higher positive temperature to ones with a lower positive temperature — that is, hotter objects heat up cooler objects, and colder objects cool down hotter ones, until they reach a common temperature. However, energy will always flow from objects with negative temperature to ones with positive temperatures. In this sense, objects with negative temperatures are always hotter than ones with positive temperatures.

most mind-blowing science year of the year (har har), temperatures below absolute zero. also, your sense of what temperature means is wrong.

World microbiome

The Earth Microbiome Project analyzes microbial communities across the globe. We propose to characterize Earth by environmental parameter space into different biomes and then explore these using samples. We will analyze 200k samples to produce a global Gene Atlas describing protein space, environmental metabolic models for each biome, 500k reconstructed microbial genomes, a global metabolic model, and a data-analysis portal for visualization of all information.

For example, we may have soil samples from a pH range of 4-6.5 and 7.3-11.2 at a range of different temperatures, nutrient loads, and soil types. To understand the full range of soil microbiota on earth we would need to explore samples whose pH is below 4, above 11.2 and between 6.5 and 7.3, and all at a range of different temperatures, nutrient loads and soil types.

Bronze Age Collapse

the worst disaster in ancient history, even more calamitous than the collapse of the Western Roman Empire.

The thing about bronze is that it requires long supply lines. To make a bronze sword in Greece, you might need tin from Cornwall and copper from Cyprus. Except for a small area in Asia Minor, tin and copper deposits don’t co-occur. The Bronze Age was therefore a time of international trade and travel. Art from the Middle East turned up in Norway and Afghanistan, that sort of thing.
2023-02-11: Evidence for a climate factor in the collapse

Here we examine the collapse of the Hittite Empire 3200 BP. The Hittites were one of the great powers in the ancient world, with an empire centered in a semi-arid region in Anatolia with political and socioeconomic interconnections throughout the ancient Near East and Eastern Mediterranean, which for a long time proved resilient despite facing regular and intersecting sociopolitical, economic and environmental challenges. Examination of ring width and stable isotope records obtained from contemporary juniper trees in central Anatolia provides a high-resolution dryness record. This analysis identifies an unusually severe continuous dry period from around 1198 to 1196 (±3) BC, potentially indicating a tipping point, and signals the type of episode that can overwhelm contemporary risk-buffering practices.