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"With each interaction, Alexa is training to hear better, to interpret more precisely, to trigger actions that map to the user's commands more accurately, and to build a more complete model of their preferences, habits and desires. What is required to make this possible? Put simply: each small moment of convenience - be it answering a question, turning on a light, or playing a song - requires a vast planetary network, fueled by the extraction of non-renewable materials, labor, and data. The scale of resources required is many magnitudes greater than the energy and labor it would take a human to operate a household appliance or flick a switch. A full accounting for these costs is almost impossible, but it is increasingly important that we grasp the scale and scope if we are to understand and govern the technical infrastructures that thread through our lives. III The Salar, the world's largest flat surface, is located in southwest Bolivia at an altitude of 3,656 meters above sea level. It is a high plateau, covered by a few meters of salt crust which are exceptionally rich in lithium, containing 50% to 70% of the world's lithium reserves. 4 The Salar, alongside the neighboring Atacama regions in Chile and Argentina, are major sites for lithium extraction. This soft, silvery metal is currently used to power mobile connected devices, as a crucial material used for the production of lithium-Ion batteries. It is known as 'grey gold.' Smartphone batteries, for example, usually have less than eight grams of this material. 5 Each Tesla car needs approximately seven kilograms of lithium for its battery pack. 6 All these batteries have a limited lifespan, and once consumed they are thrown away as waste. Amazon reminds users that they cannot open up and repair their Echo, because this will void the warranty. The Amazon Echo is wall-powered, and also has a mobile battery base. This also has a limited lifespan and then must be thrown away as waste. According to the Ay

"The big news to emerge from recent archeological research concerns the time lag between "sedentism," or living in settled communities, and the adoption of agriculture. Previous scholarship held that the invention of agriculture made sedentism possible. The evidence shows that this isn't true: there's an enormous gap-four thousand years-separating the "two key domestications," of animals and cereals, from the first agrarian economies based on them. Our ancestors evidently took a good, hard look at the possibility of agriculture before deciding to adopt this new way of life. They were able to think it over for so long because the life they lived was remarkably abundant. Like the early civilization of China in the Yellow River Valley, Mesopotamia was a wetland territory, as its name ("between the rivers") suggests. In the Neolithic period, Mesopotamia was a delta wetland, where the sea came many miles inland from its current shore."

By exchanging resources, the members of a microbial community can survive in environments where individual species cannot. Despite the abundance of such syntrophy, little is known about its evolutionary origin. The predominant hypothesis is that syntrophy arises when originally independent organisms in the same community become interdependent by accumulating mutations. In this view, syntrophy arises when organisms co-evolve. In sharp contrast we find that different metabolism can interact syntrophically without a shared evolutionary history. We show that syntrophy is an inherent and emergent property of the complex chemical reaction networks that constitute metabolism.

A sweeping effort to map a hospital's microorganisms has found that infectious pathogens hide in a place that's all about cleaning: the sink. Niranjan Nagarajan at the Genome Institute of Singapore and his colleagues sampled bacteria from bed rails, sinks and other sites in a Singapore hospital. Microbes that tend to grow in slimy 'biofilms' and cause hospital-acquired infections were prevalent on sink traps and faucet aerators, whereas skin-dwelling bacteria were abundant on objects, such as door knobs and bed rails, that are often touched. Frequently touched sites harboured multidrug-resistant microbes such as methicillin-resistant Staphylococcus aureus, which might persist in the hospital environment for more than eight years, the team suggested.

Land use change-for example, the conversion of natural habitats to agricultural or urban ecosystems-is widely recognized to influence the risk and emergence of zoonotic disease in humans1,2. However, whether such changes in risk are underpinned by predictable ecological changes remains unclear. It has been suggested that habitat disturbance might cause predictable changes in the local diversity and taxonomic composition of potential reservoir hosts, owing to systematic, trait-mediated differences in species resilience to human pressures3,4. Here we analyse 6,801 ecological assemblages and 376 host species worldwide, controlling for research effort, and show that land use has global and systematic effects on local zoonotic host communities. Known wildlife hosts of human-shared pathogens and parasites overall comprise a greater proportion of local species richness (18-72% higher) and total abundance (21-144% higher) in sites under substantial human use (secondary, agricultural and urban ecosystems) compared with nearby undisturbed habitats. The magnitude of this effect varies taxonomically and is strongest for rodent, bat and passerine bird zoonotic host species, which may be one factor that underpins the global importance of these taxa as zoonotic reservoirs. We further show that mammal species that harbour more pathogens overall (either human-shared or non-human-shared) are more likely to occur in human-managed ecosystems, suggesting that these trends may be mediated by ecological or life-history traits that influence both host status and tolerance to human disturbance5,6. Our results suggest that global changes in the mode and the intensity of land use are creating expanding hazardous interfaces between people, livestock and wildlife reservoirs of zoonotic disease.

Silicon is the second-most abundant element in Earth's crust and it plays a vital role in plant life, both on land and in the sea. Silicon is used by plants in tissue building, which helps to ward off herbivorous animals. In the ocean, phytoplankton consume enormous amounts of silicon; they get a constant supply courtesy of rivers and streams. And silicon winds up in rivers and streams due to erosion of silicon-containing rocks. Land plants also use silicon. They get it from the soil. In this new effort, the researchers began by noting that the terrestrial biogeochemical cycling of silicon (how it moves from plants back to the soil and then into plants again) is poorly understood. To gain a better understanding of how it works, they ventured to a part of Western Australia that, unlike other parts of the world, has not been impacted by Pleistocene glaciations. The soil there gave the researchers a look at the silicon cycle going back 2 million years.

ot long ago, Joe Davis, the "artist-scientist" in George Church's genetics lab at Harvard Medical School, was in Brittany, France. The region is known for thousand-year-old salterns that produce fleur de sel, or flower of salt-salt that forms as seawater evaporates. Davis was there sampling these brightly colored ponds with a microscope, and found in the shallow waters an abundance of diverse halophiles, organisms that can grow in and tolerate saline conditions. "I wondered what happens to these organisms," he said. "The salt is evaporating, the water's gone. The organisms aren't just going to disappear. Where are they?"

Carbonyl sulfide (OCS) is the most stable and abundant sulfur-containing gas in the atmosphere. It is derived from both natural and anthropogenic sources and is of key interest to scientists investigating how much carbon dioxide (CO2) plants take out of the atmosphere for photosynthesis. Measuring CO2 alone cannot provide estimates of photosynthesis (taking up CO2) because plants also release CO2 through respiration. In contrast, OCS is taken up like CO2 but is not released by respiration, and can therefore provide valuable information about the rate of global photosynthesis.

Using two independent single-cell approaches, we identified a shift in the overall immune cell composition in cavefish as the underlying cellular mechanism, indicating strong differences in the immune investment strategy. While surface fish invest evenly into the innate and adaptive immune systems, cavefish shifted immune investment to the adaptive immune system, and here, mainly towards specific T-cell populations that promote homeostasis. Additionally, inflammatory responses and immunopathological phenotypes in visceral adipose tissue are drastically reduced in cavefish. Our data indicate that long-term adaptation to low parasite diversity coincides with a more sensitive immune system in cavefish, which is accompanied by a reduction in the immune cells that play a role in mediating the pro-inflammatory response.