Science

This is how science has unraveled the mystery of Lake Tefé

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The historic drought and heat wave that hit the Amazon in 2023 caused extreme warming and unprecedented in its waters, with devastating consequences that we are seeing today. A new study published in Science details how water temperatures in key lakes reached lethal levels, causing high mortality in fish and especially river dolphins. Very high temperatures. A priori we may think that heat waves just as they come will go away without leaving any consequences. But the reality is very different, since in the Amazon, of the ten lakes that were monitored, five exceeded 37ºC during the day and there was one that reached 41ºC as if it were a spa pool. This extreme heat wasn’t just skin deep; It penetrated the entire water column, approximately 2 meters deep, eliminating any fresh refuge for aquatic life. It was literally left uninhabited. Epicenter of the tragedy. Lake Tefé, which is normally more than 7 km wide, became the focus of national and international attention after its surface area will be reduced by 75% between September and October 2023. It is literally a consumption never seen before that surprised the inhabitants of the area and also the animals. This drastic reduction in water coincided with a “massive and unprecedented mortality” of river dolphins. In a short interval, 209 dolphin carcasses were found (both from the Amazon River and Tucuxi). And precisely, the study points out that only on September 28, 2023, when temperatures reached 39.5 °C for the first timeseventy dolphin carcasses were found. The researchers also observed extreme daily temperature variation of up to 13.3°C, meaning the water went from hot tub-like heat during the day to drastically cooling at night. completely altering the conditions of the system. And living there becomes really complicated. What caused this extreme heat. The study used models to identify the culprits behind this warming. It was a “perfect storm” of factors that coincided such as high solar radiation due to completely clear skies that could not stop the sun. But the reduced depth of the water or the low wind speed also intervened, which generated less cooling due to evaporation. A long term problem. While the 2023 event was extreme, it is not an isolated incident. Study reveals worrying long-term warming trend in region, Based on satellite estimates, between 1990 and 2023, the lakes in the Amazon region have experienced a temperature increase of 0.6 degrees per decade. A great ecological crisis. The impact was not limited to the dolphins. The study also documents significant fish mortality. All because of the fact that they have a fairly narrow temperature tolerance range, meaning that the moment there is an increase, even a slight one, in temperature, they are finished off. For human populations, the consequences were equally serious. The drought and extreme heat managed to isolate thousands of people in riverside communities, leaving them without adequate access to food, drinking water and medicine because maritime transport is also severely affected. Images | Natalia Pedraza In Xataka | The Earth is headed for a new ice age, according to a Science study. And it is precisely because of global warming

When we thought we had seen all kinds of rehearsals for an invasion, China makes science fiction: robots taking over an island

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At the end of 2024, several military studies from Beijing were published outlining six different scenarios if future unification with Taiwan goes awry. So we tell that the Second World War I advised against all them because, in essence, there was talk of an invasion of the island. From then until now so much China as Taiwan have carried out all kinds of drills under the war scenario background. What you haven’t seen until now is that China has a plan B: robotic wolves. Mechanized herds. This week and through images and videosChina has shown to the world a new generation of autonomous combat systems in an exercise that simulated an invasion of Taiwan. On the landing beach, the traditional “human waves” of the People’s Liberation Army (PLA) were replaced by swarms of machines: suicide drones and well-known robotic quadrupeds like mechanized wolves. These units, developed by the state-owned China South Industries Group Corporation (CSGC), represent the first attempt to convert amphibious operations into a scenario dominated byor artificial intelligence. The broadcast images State television CCTV showed these metal “wolves” running across the sand ahead of human troops, detecting obstacles with LiDAR sensors, thermal cameras and autonomous navigation algorithms. Wolf specification. Of 70 kilos of weight and capable of carrying 20 more, these robots were divided into attack, transport and reconnaissance variants, managing to reduce the time between detection and destruction of the target to less than ten seconds. In fact, in one symbolic sequencea single human operator simultaneously directed nine robots and six drones from a 3D interface, while the devices cleared barbed wire and trenches for infantry. @elsa50356 “Breaking from China! The PLA’s latest amphibious landing drills—drones take the lead, and robotic ‘wolf packs’ rush the beach! The future of warfare is here!” 🚀🪖 #PLADrills #ChinaMilitary #Drones #RobotArmy #MilitaryTech ♬ 原创音乐 – Elsa Swarm intelligence. The training, called “Landing Operation in Taiwan” was part of an assault test coastal exercise carried out by the PLA 72nd Division, under the Eastern Theater Command, the unit operating in front of the Taiwan Strait. For the first time, quadruped robots performed as a spearheadfollowed by waves of FPV drones bombing simulated enemy fortifications. In total, the attack cycle was cfour times faster than that of a conventional square. This deployment is part of the EPL’s strategic shift from mass doctrine (the so-called human wave tactics) towards what Beijing calls “smart sea and land tactics,” a doctrine that prioritizes automation, cooperation between unmanned systems and data-driven decision making. The buts. However, the exercise itself revealed vulnerabilities: these wolf robots They lack armor, are easily detectable in open fields and one of them was destroyed by light fire. Chinese analysts they recognized limitations, but they stressed that the goal was not perfection, but rather to demonstrate that the army is willing to progressively replace human soldiers with swarms of coordinated machines. Ukraine in the shadows. The Chinese Army has incorporated direct lessons from the Ukrainian war into its maneuvers, where drones have redefined tactical and logistical effectiveness. According to Chinese military media like Daiwanthe PLA is applying the knowledge extracted from that conflict in its ground training, anticipating a future where hundreds of robots advance at 30 or 40 km/h in coordinated waves. The parallel is clear: if Ukraine demonstrated that a cheap drone can destroy a tankChina wants to prove that a network of smart machines can break coastal defenses in a matter of minutes. The current exercises, which until recently were limited to traditional landings, are already a general rehearsal of algorithmic warfare, where the human decision is reduced to an initial order and autonomous systems execute the rest. Strategic competition. Plus: The accelerated development of these systems occurs while the United States reinforces your deterrence strategy in the Indo-Pacific. According to the CIAan eventual Chinese invasion of Taiwan could occur before 2027, and the Pentagon has designed the so-called hellscape strategy: Saturate the strait with thousands of drones, submarines and unmanned vehicles to slow down Chinese forces and buy time for reinforcements to arrive. Beijing, aware of this, is creating units specialized in war against swarms, equipped with software capable of detecting, tracking and attacking targets without human intervention. Companies like Norincoanother state giant, have presented vehicles like the P60powered by the DeepSeek AI model, which can recognize targets, avoid obstacles and operate in logistics support or combat missions. A future of machines. He China’s advance towards an AI-powered war demonstrates both its technological ambition and its practical limitations. The images of robots breaching simulated beaches are as revealing as their failures in the face of enemy fire. However, beyond immediate effectiveness, Beijing’s message is unequivocal: the future of the war in the strait of Taiwan will be decided by the speed of the algorithms, not the number of soldiers. In that race, China seeks to transform mechanized warfare in smart warreplacing brute force with computational precision. The question is no longer whether robots will be present in the next invasion, but how many will be able to think, coordinate and eliminate before the first human makes landfall. Image | CCTV/China In Xataka | Less than 150 kilometers from Taiwan, the US does not stop accumulating missiles. It’s the closest thing to preparing for war. In Xataka | China has asked Russia for an airborne battalion and training. That can only mean one thing: they are preparing a landing

The Earth is headed for a new ice age, according to a Science study. And it is precisely because of global warming

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Science is largely in agreement when it suggests that the Earth’s temperature it increases more and moreand logic could lead us to think that the world is going to become in a real desert like the one in Almería. But to everyone’s surprise, what can happen is a great ice agethat is, everything ends up covered in ice. And although it may seem illogical, science wanted to give light about this topic. They have been new models from the University of Bremen and the University of California Riverside, published in Sciencewho have located right there one of the great unexpected dangers of terrestrial geochemistry: under certain conditions, excess heat can activate “biological accelerators” that then cool the planet beyond its original state. Even to reach an ice age. Beyond the rocks. Something that may be unknown to many is that the Earth has a temperature control system like the thermostat in our home. The most accepted was regulation by the slow wear of silicate rocks. However, geological records show episodes in which this natural “thermostat” fails: the Earth freezes from pole to pole, as during the Precambrian glaciations. What is missing from the equation? The new study points to the decisive influence of marine biology and nutrient cycles, especially phosphorus and oxygen. An unexpected loop. When CO₂ emissions and global temperatures rise, the arrival of phosphorus into the oceans also increases, fertilizing the proliferation of algae. These remove CO₂ thanks to photosynthesis in the water, and when they die, they transport that carbon to marine sediments, where it can be trapped for millions of years. As if it were a dumping ground for carbon dioxide on the seabed.. But the key to the loop is oxygen: the explosion of algal productivity consumes the oxygen in the water, meaning that almost no living being can live here. Under these conditions, phosphorus stops being buried and instead of being eliminated it is recycled from the sediment. This fuels new “super blooms” and closes a vicious cycle: ‘More nutrients → more algae → less oxygen → more nutrient recycling → extreme cooling’. The result is that the biological thermostat goes crazy, sequestering carbon at a frenetic pace that the rocks’ slow thermostat cannot compensate for. The new model. The new model integrate these quick feedbacksadding sedimentary chemistry, the phosphorus cycle and the oxygenation state to the traditional silicate weathering models. Surprisingly, when predicting the effect of the “great human experiment” of releasing CO₂, he finds that the system does not always smoothly return to the previous statebut it can overcompensate and take the planet to colder times, in deep glaciations, for tens of thousands or hundreds of thousands of years.​​ This only occurs when the atmosphere is less rich in oxygen, something common in Earth’s past, which may explain why ice ages coincide with intermediate periods of planetary oxygenation. Today, that same loop would make the “reward” much smoother, although there would still be the risk of long-term cooldown. If we continue burning fossils. In this way, other scientific studies already suggest that large inputs of phosphorus, whether due to massive mining or increased weathering induced by climate change, can increase the risk of anoxia and abrupt cooling events, although this scenario would take centuries or millennia to develop. This is why the acceleration of the phosphorus cycle together with the increase in CO₂ concentrations is conditioning us to the climate changes that we will see in a few million years. And although the Earth system may have the mission of stabilizing, the reality is that this system cannot always be trusted. Images | Denise Schuld In Xataka | We have just identified the oldest glaciers in the world. Where: under South Africa’s big gold mines

Someone has said that melatonin damages the heart. The reality, according to science, is that we can be calm

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Melatonin is a hormone that now is on many people’s lips being a key element in the regulation of our biological clock, and above all being well known for its relationships with sleep induction. It is precisely for this last reason that in recent years people have been supplementing with melatonin pills to be able to sleep better or regulate their sleep schedules more, but now the alarms have gone off about the possible side effects it may have. The alarm voice. There are many benefits that melatonin has with its continued use as a supplement beyond those related to sleep, such as anti aging thanks to its antioxidant capabilities. But beyond the benefits, a study has raised the alarm: it can cause heart failure. However, there is much to qualify in this statement. Obviously, something like this can generate great unrest in society, precisely because it is a widely used supplement in different countries because it can be purchased without any type of medical prescription (except for the highest doses). And this attraction has been used to create pills, gummies or even infusions that have melatonin inside. But the reality is that nothing we ingest can be harmless to our body, especially if very specific safety guidelines are not followed. Although in the case of melatonin everything indicated that it was completely safe and that everything behind it was something positive. Until now. What the study says. The focus of the controversy centers on a preliminary study (and this is important) that is going to be presented at the American Heart Association Scientific Sessions 2025. This work analyzed the medical records of more than 130,000 adults with insomnia, comparing 65,414 people who had used melatonin for a year with another group who had not used it. The results of this study they pointed in this case because users who used melatonin chronically were twice as likely to be diagnosed with heart failure. But they went further by showing that there was a 3.5 times greater risk of hospitalization for heart failure. But saying ‘double’, the truth is that it does not provide much information (beyond fear), but what is important here would be to talk about the absolute increase in risk, as the Secretary of State for Health points out in his X account. Tranquillity. But the reality in this case is that there is no need to sound the alarm immediately because of the ‘fault’ of a study that has not yet been reviewed (since it is not even published in a journal). Right now there is a large amount of scientific evidence that proves how safe melatonin isand a single study does not put in check all the scientific literature behind it, although it does open a door to be able to investigate in a more in-depth way. melatonin side effects. For example, in 2022 a systematic review was published on high doses of melatonin in adults found minor adverse events such as drowsiness, headache or dizziness, but no increase in serious adverse events. The same thing happened with the StatPearls article of 2024 which indicated there was no evidence of toxic effects. Specifically in chronic use we have a 2023 study by Givler which confirms that the administration of between 5-6 mg of melatonin per day does not generate serious long-term risks. Although logically it is important to use it above all as an ‘help’ to have more adequate sleep hygiene with the aim of not depending on exogenous melatonin to be able to sleep. And it is necessary to carry out studies that are appropriate to look for this correlation. The study that has highlighted melatonin is not the most appropriate as it is observational and not a randomized clinical trial. This means that it has not been possible to verify exactly whether these differences are due to chance and, above all, there has been no control over the patient groups, since it has been done with their clinical histories. The correct thing to do in these situations is to propose a study with two groups: one where patients take melatonin and another where they do not. But until we reach this point, it is important to calculate the number of patients needed, how they are selected and the baseline characteristics they must have so that there are interchangeable patients in both groups and many other factors. Everything necessary so that the conclusion of the study has great external validity for the entire population. Investigation remains. Logically, any type of supplement, and especially if it is hormonal, can lead to different side effects. The issue in this case is that research is needed to look for side effects and ask ourselves if it is necessary for doctors to start prescribing it in all doses. And, as we have said before, a prescription is only needed for the highest doses, but the lowest doses can even be found in a supermarket. Although whenever you have doubts about the safety of the medication, the important thing is always to consult with your primary care doctor so that the dose can be adjusted based on the particular history of each patient. Images | Isabella Fischer Robina Weermeijer In Xataka | Of course melatonin has side effects. There is nothing special or alarming about it

The memory of young people is deteriorating at a record pace. Science thinks it knows why

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The memory problems among youth are beginning to be worrying. This is what a new study scientist published in the magazine Neurology and that tries to answer why this happens and above all the reasons that exist for our youth to begin to be in decline in regards to to your memory. The surprise. What can logically be expected is that with the passage of time and accompanying aging, memory problems begin to appear that anticipate dementia. But in the United States, after analyzing millions of people, they have seen that the population most affected by this ‘mental fog’ is precisely the youth. And the result in this case is very important: self-reported cognitive problems among young adults aged 18 to 39 have almost doubled in the last decade. But it is something that we are not understanding. The study. To reach this conclusion, a total of 4.5 million people who responded to the national survey of the Behavioral Risk Factor Surveillance System (BRFSS) from the CDC and collected between 2013 and 2023. In this way, there was a truly large sample of people to analyze, although limited only to the United States. The results in this case were quite clear: the prevalence of adults reporting a cognitive disability increased from 5.3% in 2013 to 7.4% in 2024. But what was truly interesting came when separating the results by demographics: In young people aged 18 to 39, the rate skyrocketed from 5.1% in 2013 to 9.7% in 2023. This group is, in fact, the driver of the overall increase in the entire population. In those over 70 years of age we saw a decrease in prevalence from 7.3% to 6.6%, when logic tells us that it should increase. Other factors. In order to know the reason for this increase, other factors behind the respondents had to be traced as well. In this case it aimed at the income level: Have low income with less than 35,000 dollars a year left us with a prevalence that increased from 8.8% to 12.6% With high incomes (>$75,000) the rate was much lower, although it also dropped from 1.8% to 3.9%. But the same thing happens with the educational level, where young people who did not even have high school went from 11.1% to 14.3% while those with university degrees increased from 2.1% to 3.6%. And even in order to obtain much more information, they wanted to analyze the prevalence according to the race of young people, where it could also be seen, for example, that Asian adults are the ones who reported the least cognitive problems. Specifically, the data is the following: American Indians/Alaska Natives: continue to have the highest prevalence, rising from 7.5% to 11.2%. Hispanic adults: saw a significant increase from 6.8% to 9.9%. Black adults: The rate rose from 7.3% to 8.2%. White adults: increased from 4.5% to 6.3%. Asian adults: Consistently maintained the lowest rates, going from 3.9% to 4.8%. What is happening? With all the data in hand, it is logical to think about what is happening so that young people increasingly have more cognitive problems. And for researchers there is not only one valid answer, but there are several that are being proposed. The first of them is that there is greater awareness about this problem, and that is why there are more people who raise their hands when presenting it and have no doubts when it comes to seeking help. But there are also other factors such as economic stressors or work problems that seem to be contributing to these trends. All this without forgetting that the greater presence of digital tools may have meant that our memory is not as trained. But all the social and economic factors we face today can also mark an important milestone when it comes to the real burden on our minds. This ‘overload’ can condition the appearance of these highly relevant cognitive symptoms. Images | Eliott Reyna Milad Fakurian In Xataka | Finding a job had always been a good way to escape poverty: in Spain it is no longer true

Halloween is coming and the temptation is to put on some terrifying plastic contact lenses. Science has its reservations

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Costumes, scares, moviespassages of terror and also the occasional party is undoubtedly something that we will see in this Halloween nightalthough among all these elements there is a protagonist that can undoubtedly become a risk to our health: colored cosmetic contact lenses. The color of the eyes. To dress up in the most faithful way to the character we want to resemble, eye color may be essential. In the case of Halloween, it may be interesting to have them red or some other color that conveys a feeling of fear, such as those of the famous ‘Valak’ or ‘The Nun‘. But it can undoubtedly be a serious problem for our health. And on many occasions we want something that is economical to be able to dress up and we can choose to buy these contact lenses in a store that is not specialized in these products such as a bazaar. All because to wear it for a while at night you are not going to invest a large amount of money in a special contact lens. But we forget that we are buying a product that will be in contact with our eyes, which are really delicate. Doubts. Ophthalmologist Damián Teillard through his TikTok account It alerts us to all the problems that can arise, such as infections, corneal abrasions, blurred vision or eye fatigue when colored contact lenses are used without adaptation, with poor hygiene or throughout the night. That is why you are committed to making the purchase at an authorized optician to try them the days before. The scientific evidence. But beyond what this ophthalmologist says, we also find a large amount of scientific literature that documents all of these problems. An exampleor we have in the magazine eye that reviews these cosmetic contact lenses and demonstrates the appearance of severe microbial keratitis associated with these products that are purchased without health control. More cases. We have another example in the TFOS report on the impact of contact lenses on the ocular surface, details that their inappropriate use (sleeping with them for example) damages the epithelium, alters the tear film and increases the risk of infection. Something quite common in a situation where many people opt for these contact lenses without having ever worn this product before, so they lack the recommendations to avoid problems when wearing them. In this way, the evidence on periocular cosmetics and ocular surface underlines that makeup and formulations around the eye They can irritate, destabilize the tears and increase discomfort if combined with contact lenses. Elevation of risk. With all this, we can see how buying contact lenses in bazaars or unauthorized websites that have poor quality produces a significant injury that can end in visual loss in the most severe cases. Among these complications we see the keratitis, conjunctivitis or corneal abrasions and ulcers that require ophthalmological treatment in many emergency cases. How to use it correctly. In order to avoid all these problems, the crucial thing is to purchase them from authorized opticians and with the advice of ophthalmological professionals. But you must also follow the basic recommendations for contact lenses, such as sleeping with them, putting them on with clean hands, not sharing them with several people, and always applying makeup after putting on the lenses and removing makeup with them to protect the ocular surface. With all this you can achieve a night of terror but without the eye ending up suffering from the misuse of contact lenses that we find in any bazaar or on the internet. Images | Grégoire Hervé-Bazin In Xataka | There is nothing that makes blue eyes blue. If we want to understand why, we have to turn to physics

Breathing through your ass is safe (according to science)

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Although a priori we have been taught from childhood that the lungs are the organ responsible for our breathingthe reality is that breathing through the ass is also possible. And it is not a theory, but rather it has been put into practice, as a clinical trial has shown published in the magazine Med who has named this technique enteric ventilation. The current situation. When a person is in a critical condition, it is quite common to perform an intubation with the aim that a ventilator can do the action of exhaling and inhaling with the aim also of applying an extra dose of oxygen when there is respiratory depression or simply controlling this route. Although it is also a technique that can be seen in an operating room, in surgery, when anesthesia is applied. The problem is that sometimes intubation is not possible, because the airway is very compromised or simply because the lung is in a state that prevents it from performing its normal function. This forces us to look for alternatives to maintain blood oxygenation, and one of them is this enteric ventilation through another area such as the rectal area, which is presented as support but not a substitute, but is a further advance in emergency medicine. The technique. It has already been tested by the Takanori Takebe research team of the Cincinnati Children’s Hospital and the Osaka Universityis presented as a complementary oxygenation pathway in very serious respiratory emergencies. In Takebe’s own words“does not seek to replace mechanical ventilators or ECMO, but rather to offer a temporary means of support to allow the lungs to rest.” The operation. The idea of ​​breathing through the rectum was not born in the laboratory, but in an aquarium. In 2021, Takebe and his group they published in Med a pioneering study in which they demonstrated that animals such as mice, rats and pigs could survive low-oxygen environments if their intestines received oxygenated perfluorodecalin. This liquid, a perfluorocarbon Chemically inert, it can transport oxygen in concentrations much higher than what an erythrocyte can do. And to test it, they introduced it through the rectum, causing the animals to reverse the lethal hypoxia and reduce the need to use the lung as a ‘pump’ to ventilate the body. The administration was enteral, that is, through the rectum. In animal models, intestinal oxygenation managed to reverse lethal hypoxias and reduce the need for pulmonary ventilation. The next step. Once tested on animals, the idea was to move on to humans and see if it was safe. To do this, they recruited 27 healthy volunteers who received one liter of perfluorodecalin not oxygenated by a controlled enema. In this case, none of them had hypoxemia and the goal was not to see if it could be reversed, but to check if they had any strange reaction. And the result was a success: there was only a little diarrhea (a good thing considering what could have happened). But the most important thing is that the results coincided with what was observed in animal experiments, and above all they confirmed that there is no significant damage or inflammation in our intestinal mucosa. What’s coming Takebe’s group is already planning a phase II clinical trial with patients suffering from moderate hypoxemia, in collaboration with hospitals in Japan and the United States. In this case, oxygenated PFD (O₂-PFD) will be used to determine if intestinal absorption can really raise blood oxygen levels as it occurs in animals, although expectations are very high. If we look at the scientific literature, there are already different application possibilities. As published in Frontiers in Physiology in 2023 the potential of perfluorocarbons can be highlighted as alternative oxygen carriers, both for lungs with edema and for emergency medicine where it cannot be easily intubated or the lung is not 100% fit for it. In parallel, the field of liquid ventilation has remained active among critics and intensivists: works such as the one published in Intensive Care Medicine Experimental in 2020, they pointed since oxygenated fluids could relieve pulmonary stress in patients with distress acute respiratory illness, serving as a “bridge” in life support therapies. His comic side. In 2024, Takebe’s group received he Ig Nobel Prize for his research in enteric ventilation, an award that celebrates research that first makes you laugh and then makes you think. But, beyond humor, Takebe himself emphasizes that what began as a biological curiosity is giving rise to real biomedical innovation. And although it remains to be confirmed that the human intestine can actually oxygenate blood effectively, accumulated data in animals and the first safety trials put enteric ventilation on the border between experimental biomedicine and advanced critical medicine. Far from being an extravagance, research in liquid oxygenation is part of a growing area that seeks alternatives to invasive mechanical ventilation, especially in situations where resources or time are limited. And if all goes well, in the future a treatment that today sounds unthinkable—injecting liquid oxygen through the intestine—could become another tool in the arsenal of intensive care units. Images | Alexey Elfimov In Xataka | We’ve gone from “breakfast is the most important meal of the day” to “I grab something quick and stick with it.” And that has problems

Science says the real danger is in how we do it

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A very typical gesture in our daily lives is to reuse the bottles we use to drink water or any other beverage. Something that is usually done to reduce the carbon footprint that can be caused by using a bottle only once and throwing it away. But at a time when microplastics are the order of the day, the truth is that it makes us think If reusing a bottle is harmful to us. But we are not only talking about the plastic bottles that we buy in the supermarket with water or any other liquid such as a soft drink, but also the classic bottles that we are used to seeing in many places that They promise to keep you warm or cold inside.. Its plastic construction can set off alarm bells after seeing how microplastics have been found in the testiclesthe breast milk and other parts of the bodyit is logical to think that if we use the same bottle twenty or thirty times in the end we are consuming this type of substance. The fear of microplastics. Little by little they get to know each other details about the effect that the consumption of microplastics has about our health, especially fertility. This means that we basically have to question the containers from which we consume food in order to ‘protect ourselves’ from its bad effects, as can occur in these bottles in container containers. The problem. Popular belief states that reusing bottles could pose a significant risk due to the alleged accumulation of bisphenol A (BPA) and the proliferation of dangerous bacteria if they are not cleaned daily. However, current scientific evidence intensely qualifies these statements, distinguishing between real risk factors and unfounded precautions. The release of bisphenols. Several studies have evaluated the migration of BPA and phthalates from reused bottles. under real use conditions. A recent experiment from 2021 simulating daily use in more than 20 types of bottles concluded that no migration of bisphenol A was detected in the stored water, even after several weeks of reasonable reuse. And the most interesting thing is that the classic aluminum bottles used as thermoses were also included. Other scientific articles agree: the release of BPA depends fundamentally on the type of material, exposure to high temperatures and extreme wear, not on the mere fact of filling them with tap or refrigerator water. Bottles suitable for food use, well maintained and not subjected to excessive heatdo not dangerously increase exposure to BPA. This logically changes radically if liquids are poured at high temperatures, which can cause more microplastics to be released. This is why you must always take into account the temperature of the liquids that are stored, so that it is the same as the original liquid that was stored. But there are also different opinions. In this case, food technologist Luis Ribera, director of the Saia food safety consultancy, has warned of the risk of reusing bottles manufactured for single use, as reported by El Confidencial. ​Although he goes further by stating that the real danger lies in the microorganisms that can appear in these bottles. Bacteria and bottles. Precisely, it is also a recurring theme, since logically on the surface of the bottle you can accumulate different common microorganisms like for example Escherichia coli either Staphylococcus. This is something that can be common, especially when a sugary drink has been stored, which leaves a substrate on the plastic walls, as if it were a Petri dish. But the key in this case to avoid the accumulation of bacteria logically lies in hygiene. Recent studies show that regular cleaning Soap and water is enough to keep the bottles safe. In cases in which high levels of bacteria have been reported, the analyzes always point to the lack of frequent washing or the use of cracked containers, rather than the rational reuse for drinking water as many of us do at home to avoid having to buy more bottles. Is it dangerous to reuse bottles? With this evidence, we can have several clear conclusions. The first of them is that there is no health prohibition when it comes to using bottles that are reusable and that have been manufactured to contain water. The second is that the associated health risks are almost exclusively due to poor hygiene habits or extreme wear and tear of the packaging. And the third is that if a bottle has not been manufactured to give it more than one use, Yes, we must be careful with its reuse.. In this way, neither the migration of bisphenol A nor the “bacteriological danger” justify throwing away your bottle after a single use, as long as it is used sensibly and basic hygiene is maintained. Science supports responsible use and regular cleaning, debunking some of the alarmist discourse around reusing plastic bottles for tap water. Images | charlesdeluvio Nigel Msipa In Xataka | The true size of the microplastics that populate our lives, exposed in this disturbing graph ​

science believes it has an explanation

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Walking down the street and seeing someone walking with their eyes downward can make us instantly think that something is happening to that person emotionally, such as being sad. But the reality is that walking down has many meanings and that have been proven through sciencewhich go far beyond the field of psychology and makes us rethink the thoughts we have when we see someone in this situation. The body language. One of the letters of introduction we have to the world is undoubtedly the gestures we make. It is not the same to be with them all the time. crossed arms which may indicate a more closed attitudeto be much more open in front of another person. And the look is another fundamental letter of introduction that we can understand perfectly. What psychology says. The most widespread interpretation of looking down while walking is attributed to the insecurity, shyness, sadness or low self-esteem. It is a fact that avoiding eye contact can seem evasive and, in a society like ours, is often considered a sign of vulnerability or emotional processing. This is something that has been collected in different studies focused on non-verbal communication where they reinforce this idea: the hunched posture, the gaze towards the ground and the absence of eye contact can indicate internal states such as introspection, emotional stress or the need for protection from the environment. However, the field of psychology warns that this overly simple or ‘generalist’ interpretation is inaccurate. To understand it we can go to other cultures such as the Japanese, where looking at the ground is a sign of respect or modesty, or can even be interpreted as a form of concentration or reflection. In this way, the social context, personality and frequency of the gesture make the difference between a ‘good clinical indication’ and perfectly normal behavior. Neuroscience. But beyond psychology, Neuroscience also has a lot to say in this field to thoroughly study why, in many situations, looking down is a very useful strategy. Studies published in journals such as Nature demonstrate That directing your gaze toward the ground helps adjust your balance and reduces the risk of tripping. Within these studies, brain activity and movement patterns have been specifically measured in people walking in different environments. And the conclusion is quite clear: looking down provides the brain with critical information about the terrain and allows you to adjust your step, especially if there are obstacles or the ground is uneven. In this way, if you go in the middle of the field for example, the normal thing is to look down to avoid tripping or ending up on the ground. The same occurs with a work published in 2021 that observed that this position improves stability in older people and also when the cognitive load increases, for example, when we are distracted. Thus, far from being just an emotional symptom, it is also a rational and functional response. facing physical and mental challenges. Mental health. Should every gesture of looking at the ground worry us? The clinical literature clarifies: if the gesture appears in isolation, it does not imply problems. But if it is combined with other signs such as social isolation, apathy or mood changes, it can be part of a picture of depression, anxiety or stress. The problem is that a simple look down the street is not enough to know this, but you must know that person much more. But the evidence is quite clear in this sense: ​there is a relationship between emotions and posture, but it is never a single indicator. Beyond the myth. In this way, every time we see a person with their gaze downcast, we don’t always have to think about the most negative thing, but we don’t always have to think about the most positive thing either. The reality is that if we are walking down a street Looking at the ground serves to avoid obstacles, process information while walking or adopt multitasking strategies (or even if you are lucky to find a ticket). Images | Caspar Rae In Xataka | The psychology of doomscrolling: the trap our brain is programmed to fall into again and again

Science has found the secret of the giant tomato, but it may be at the cost of destroying its good flavor

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Imagine being able to take a small, bitter, wild eggplant and with a single genetic tweak, turn it into a very different variety, much larger and ready for the market. This, it seems something out of a science fiction movieit may be a reality that is getting closer, as one pointed out published study in the magazine Nature who deciphered the genetic “instruction manual” of the entire eggplant family and also the tomato. The problem. We are currently living in a time in which the climate is changing radically. with increases in temperatures or reduction in rainfall that reach our fields. This forces us to have a ‘plan B’ in the bedroom that allows us to continue having crops efficiently and to be able to feed an entire population despite there being a climate decline. And genetics in this case is preparing for it with different changes. The agriculture of the genetically modified foods is starting to gain strength. The fact of modifying the seed of a fruit so that it comes out with significant improvements, such as being juicier, larger or more efficient, is the future of agri-food engineering. And all to be able to respond to an increasingly growing demand for food, but with a space suitable for it that is smaller. A commitment to flavor. But these genetic alterations raise many questions. The goal right now is to have fat tomatoes or eggplants that are also very elongated but without thinking about anything else. If we eat a tomato on many occasions what we want is for it to be juicy and good. But genetic modification may overlooks these types of essential components to be more ‘productive’ and nutritious. But the objective in this case of the investigation that is currently being carried out is on size. And if one tomato ‘from the future’ can be equivalent to three ‘current’ ones, the truth is that we will have taken a very important step. And this is already being seen. The investigation. An international team of scientists has created the first “pangenome“of the genus Solanum. This is not only the tomato and eggplant family, but also the potato and dozens of other crops consumed locally around the world, and which opens the door to a great evolution in the field of food and the agri-food industry. The objective. For the researchers, the objective was quite clear from the first moment: to know why a gene that produces a desirable trait, such as having a larger fruit in a tomato, does not work when tried to apply it to an eggplant. The answer in this case is quite clear: genetic redundancy. The obstacle. In this case, scientists saw that the main obstacle to this genetic modification not being applied was in gene duplications, known as paralogues. In order to understand this concept we can imagine the light in a room that would be our phenotype and that in order to turn it off we need to press two switches that control it. These switches are what we know as paralogs, and in order to turn off the light it would be necessary to deactivate both. This is what happens in many species, which have created ‘backup copies’ of their switches so that turning off just one would do absolutely nothing and would not materialize in their phenotype, such as their size. That is why this team analyzed 22 species of Solanum and discovered that, although the overall structure of chromosomes is similar, thousands of key genes have undergone different variations throughout their evolution. The brake gene. Scientists have long known that a gene called CLAVATA3 (CLV3) is the master regulator of fruit size in tomatoes. Its function is, basically, to act as a brake. It tells stem cells at the plant’s growing points (the meristems) when to stop dividing. Thus, when this gene is mutated or ‘off’ the brake is released and the plate produces more cells, resulting in larger flowers with more seed compartments and also a much larger fruit. And here is the key to how a tomato will end up being domesticated. The problem is that the tomato has an additional “handbrake”, which is a paralogous gene called CLE9. In this way, even if we alter CLV3, it will not have its full effect, since it will have this extra switch that must also be altered. CRISPR. It is a genetic ‘editing weapon’ that will allow us to achieve the effect we want and cut the brake on CLV3 so that the fruits can evolve. The scientists ran the tests on the African eggplant, a species that lost its CLE9 handbrake a long time ago, but has a functional copy of CLV3. When scientists used CRISPR to deactivate that only functional copy, the result was massive and uncontrolled growth, demonstrating that that gene was the only brake he had left. In another experiment, we used S.prinophyllum that did not have CLE9, but did have two units of CLV3 (CLV3a and CLV3b). In this case, when the researchers edited a single copy, the brake was weakened and the plant produced fruits with more lobes and therefore slightly larger fruits. But when they removed the two brakes, uncontrolled growth was seen again. The surprise find. While research was being carried out along these lines, experts saw something they did not expect: a completely different gene on chromosome 2 called SaetSCPL25-like acted as the main size “switch” in the African eggplant. Something that responded to a small natural mutation of this gene that was associated with the additional locules per fruit. To check this, they did the experiment in reverse. They took this new gene and they cracked it with CRISPR on a standard tomato. The result in this case is that fruits were produced with more locules, that is, they were much larger. In this way, the researchers had found a second genetic path to increase the size of the fruit in addition to breaking its brakes. … Read more

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