The Tianwen-1 probe, the first that the Asian giant has sent to Mars, will help study the geology and soil characteristics of the red planet, and will also search for water and ice.
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Why were Europeans the ones who brought so many diseases to America and didn't the other way around?
The Old World transported a large number of diseases to the New World, but disease transmission was not bilateral. At least not in the same proportion (it is still debated whether syphilis, for example, came from America to Europe).
The fundamental reason for this asymmetry, however, lies in a factor that apparently could seem natural, ecological or even flower power: animals.
Domestication and zoonotic diseases
Most Old World diseases originated in animal livestock, especially domesticated animal farms. that were not present in America.
The Native Americans hardly had domesticated farm animals, and therefore there were not many zoonotic diseases (those spread by close contact between animals and humans). As explained Jeffrey D. Sachs in his book The ages of globalization:
The list of diseases that arrived from Europe was long and deadly, and included smallpox, influenza, typhus, measles, diphtheria, and whooping cough. Smallpox was the great mass murderer: it wiped out an alarming proportion of the native populations that encountered the newly arrived Europeans.
The exchange between the Old and New Worlds was very fruitful regarding agricultural products: America provided Europe with corn, potatoes and tomatoes; Europe provided America with wheat and rice. Sheep, goats and pigs also arrived there. And addictive products also flowed bidirectionally: tobacco or sugar cane. But the diseases were much more prevalent in the New World. simply because the natives were not so accustomed to domesticated animals.
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The news
Why were Europeans the ones who brought so many diseases to America and didn't the other way around?
was originally published in
Xataka Science
by
Sergio Parra
.
Systems designed to detect deepfakes (videos that manipulate real-life images through artificial intelligence) they can be fooled, as this study suggests.
Researchers have shown that detectors can be defeated by inserting adversarial examples into each video frame. Adversarial examples are slightly manipulated inputs that cause AI systems, such as machine learning models, to make an error.
Attacking blind spots
In deepfakes, a subject's face is modified to create realistic and convincing images of events that never happened. As a result, typical deepfake detectors focus on the face in the videos: first they track it and then pass the data from the cropped face to a neural network that determines if it is real or fake.
For example, the blinking of the eyes It doesn't play well in deepfakes, so detectors focus on eye movements as a way to detect that the video is fake.
However, if the creators of a fake video have some knowledge of the detection system, they can design inputs to target the detector's blind spots and avoid it.
The researchers created a confrontation example for each face in a video frame.. But while standard operations, such as compressing and resizing a video, typically remove adversarial examples from an image, these examples are designed to resist these processes. The attack algorithm does this by estimating over a set of input transformations how the model classifies images as real or fake. The modified version of the face is then inserted into all video frames. The process is then repeated for all frames of the video to create a deepfake video.
To improve the detectors, the researchers recommend an approach similar to what is known as Adversarial Machine Learning o adversarial training: during training, an adaptive adversary continues to generate new deepfakes that can bypass the current state-of-the-art detector; and the detector continues to improve to detect new deepfakes.
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The news
For the first time, deepfake detectors can now be fooled and that is a problem
was originally published in
Xataka Science
by
Sergio Parra
.
It has been confirmed that a planetoid, nicknamed "Farfarout", which It was first detected in 2018, It has become the most distant object orbiting our Sun.
The Minor Planet Center now has given him the official designation of 2018 AG37. It will receive an official name after its orbit is better determined in the coming years.
Farfarout
Farfarout's average distance from the Sun is 132 astronomical units (au); 1 au is the distance between the Earth and the Sun. For comparison, Pluto is only 39 au units from the Sun.
Farfarout's journey around the Sun takes about a thousand years, crossing the orbit of the huge planet Neptune each time.
Farfarout is very faint and, based on its brightness and distance from the Sun, the team estimates its size to be about 400 kilometers across. As explained Chad Trujillo, astronomer at the University of Arizona:
Farfarout's orbital dynamics can help us understand how Neptune formed and evolved, as Farfarout was likely thrown into the outer solar system by getting too close to Neptune in the distant past. Farfarout is likely to interact strongly with Neptune again as their orbits continue to cross.
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The news
This planetoid that orbits our sun has become the most distant we know: it is 4 times farther than Pluto
was originally published in
Xataka Science
by
Sergio Parra
.