Home – The Conversation |
- After Afghanistan, US military presence abroad faces domestic and foreign opposition in 2022
- Online tools put will-writing in reach for most people – but they're not the end of the line for producing a legally binding document
- When researchers don't have the proteins they need, they can get AI to 'hallucinate' new structures
- How cybercriminals turn paper checks stolen from mailboxes into bitcoin
- 'Don’t Look Up': Hollywood's primer on climate denial illustrates 5 myths that fuel rejection of science
- What's the difference between sugar, other natural sweeteners and artificial sweeteners? A food chemist explains sweet science
| After Afghanistan, US military presence abroad faces domestic and foreign opposition in 2022 Posted: 05 Jan 2022 05:48 AM PST  In August 2021, the U.S. military withdrew from Afghanistan after fighting a war there for nearly 20 years. In addition to Afghanistan, the U.S. has reduced its military presence in several other conflict zones in recent years. It has lowered troop levels in Iraq from 170,000 in 2007 to 2,500 in 2021, and in Syria from 1,700 in 2018 to around 900 today. While these reductions may seem like a U.S. military withdrawal from the world stage, its presence overseas remains vast. As political scientists, we examine the costs, benefits and perceptions of U.S. military deployments abroad. Our research shows that though the scope and location of its deployments may change, the U.S. military remains an influential global player. Domestically, pressures to reduce the defense budget make overseas deployments an attractive target to cut. Internationally, opposition to hosting the U.S. military can also increase the cost of maintaining bases. For the U.S. to maintain its influence, it will have to adapt to these increasing international and domestic pressures against its foreign military presence. Alternatively, the gradual withdrawal from its overseas commitments will make it harder for the U.S. to maintain its alliances and the international institutions it has crafted. A history of deploymentsU.S. military deployments and bases reassure allies, deter rivals and support humanitarian missions and military training. They also act as a command center for varied operations, including drug interdiction and counterterrorism. A base gives the U.S. the ability to credibly respond to emerging threats and crises in a region. They can range from small listening posts with a handful of people to a virtual city like Camp Humphreys in South Korea, which hosts over 35,000 military and civilian personnel. We recently published updated data on the number of U.S. troops deployed overseas, based on reports published by the Department of Defense's Defense Manpower Data Center. The data shows that in 2021 the U.S. had 171,477 service members located overseas, a small decease from 177,571 in 2020. Beyond personnel, the U.S. owns over 600 locations used by the military in countries and territories. These sites range from larger bases and training ranges to smaller sites, including petroleum product storage stations in Turkey and Portugal and Army golf courses in Germany and South Korea. The U.S. established its first permanent overseas military facility at Guantánamo Bay, Cuba, in 1898 at the end of the Spanish-American War. The U.S. Platt Amendment stipulated the legal option for the U.S. to buy or lease land from Cuba in perpetuity. Notably, the Cuban government does not recognize the U.S. right to hold Guantánamo and does not cash the U.S.'s monthly US$4,085 rent checks. Beyond that, except for bases in the Philippines, U.S. bases remained limited worldwide until World War II. The Second World War saw the U.S. expand its base network through aid agreements and the military occupation of Germany and Japan. Over 16 million service members were mobilized for the war, and around 7.6 million were deployed to conflicts in Europe, Asia and Africa. Bases in this period were established or leased in areas like Canada, France, Germany, Japan and Guam. After the war, the number of U.S. personnel overseas declined globally. Yet new engagements in North Korea, Vietnam, Iraq and Afghanistan were accompanied by rapid and large deployments to Asia and the Middle East. A shifting presenceWhile the U.S. has maintained a global military presence for the last 70 years, its approach has changed over time.  Recently, U.S. military deployments, many without a formal U.S. military base, have been used to help counter China's expanding influence in Africa. Though China's involvement in Africa has generally been economic, the establishment of the Chinese People's Liberation Army Support Base in Djibouti in 2017, coupled with recent news of China's plans to build its first Atlantic base in Equatorial Guinea, suggest that China may seek increased military influence in Africa in the future. Comparing the U.S. military presence in Africa between 2001 and 2021, we can see an increased number of African states with U.S. forces present. Notably, in 2007, the U.S. established Africa Command, a regional Defense Department command, based in Germany, specifically responsible for operations in and relations with all countries in Africa. The U.S. has maintained a broad number of small deployments throughout the continent during this time. Many are composed of special operations and special forces units focusing on counterterror and military training operations. Djibouti is particularly notable, as the U.S., China, France and the United Kingdom all have military facilities there.  Reducing the U.S. military footprintThe scope of the U.S. global military footprint has become increasingly contentious in Congress in recent decades and in some of the countries hosting U.S. personnel. The Trump administration sought to reduce the number of troops in countries that failed to increase their share of the cost for hosting U.S. troops. The Biden administration has reversed some Trump-era policies. For example, it stopped Trump's planned troop drawdown in Germany.  Yet the Biden administration also continues to explore ways the U.S. could adjust its military footprint. The Defense Department, in November 2021, announced the completion of its Global Posture Review, examining the U.S. military's presence overseas. Both administrations' preference to cut the number of overseas personnel is rooted in the political and financial costs of maintaining deployments. The ability to use new technologies, such as drones, rather than people in combat operations, has also allowed U.S. policymakers to shift away from larger bases. Instead of a massive complex like Ramstein Air Base in Germany that the Defense Department values at $12.6 billion, it can spend just over $100 million to build small sites for drone operations like Niger Air Base 201. However, if the U.S. wishes to continue to influence regional politics and use its military as a credible deterrent to rival powers, technology alone is unlikely to be sufficient. Shared opportunities and pitfallsWe have discussed previously how the U.S. gains influence and ease of operating in exchange for the defense of other nations. But this American gain comes with several costs for host states. Deployments can cause noise pollution, long-term environmental harm, opportunities for crime and stoke broader grievances about imperialism and militarism. And they can generate traffic and accidents when local driving customs differ substantially from what U.S. troops are accustomed to, or where large and frequent military convoys traverse busy locations. [Understand what's going on in Washington. Sign up for The Conversation's Politics Weekly.] Opposition movements built upon grievances with the U.S. presence have fueled national movements to remove U.S. bases in South Korea and Japan. In some cases, like the Philippines, such movements have been successful. Over time, formerly autocratic host countries have become democratic, like South Korea, and have made public support by the civilians of host states critical if the U.S. desires to maintain its troops overseas. Both increasing external competition and growing domestic political pressures may lead to reduced opportunities for the U.S. as it navigates new and existing host relationships.  Michael A. Allen has received research funding from the Department of Defense's Minerva Initiative, the US Army Research Laboratory, and the US Army Research Office. Carla Martinez Machain has received funding from the Department of Defense's Minerva Initiative, the US Army Research Laboratory, and the US Army Research Office. Michael E. Flynn has received research funding from the Department of Defense's Minerva Initiative, the US Army Research Laboratory, and the US Army Research Office. |
| Posted: 05 Jan 2022 05:48 AM PST  The promise of online wills is undeniable. Online programs offer people an easy way to write their wills. Online templates can be completed anywhere, at any time. There is no office appointment, no indiscreet questions from a lawyer about who is getting what. You don't have to leave home and you don't even have to get dressed. I'm a law professor who teaches will and trusts, and I have no doubt that online wills are the wave of the future. I bought stock in the online will preparation company Legal Zoom when it made its market debut on June 30, 2021. But, despite my enthusiasm (and hopefully successful investment), online wills aren't right for everyone, nor are they appropriate in all circumstances. Moreover, it is important to remember that simply filling out an online form doesn't produce a legally binding will. What's great about online wills is the increased ease that they offer, which is significant in terms of making will-writing more palatable to people. Online wills are also important in terms of equity and opportunity. As many as 68% of Americans die without a will and, while reasons vary for this stunningly high number, one factor is likely lack of access to legal services. People contemplating will-writing are understandably deterred by the daunting task of finding the right lawyer and the possible cost of the transaction. Online services like Legal Zoom, US Legal Wills and Nolo's Quicken WillMaker & Trust pointedly advertise the low cost of their services and offer basic packages for a will starting at around US$90. Other websites, like Rocket Lawyer, advertise free will templates. Online wills have the potential, therefore, to bring wills and estate planning to populations that might not otherwise have contact with legal services – assuming that the person writing the will has computer and internet access. Similar tools for medical directives and living wills make end-of-life preparations more accessible as well. State law is the bottom lineIncreased accessibility, however, is only part of the story. One fundamental problem with online wills is that they are not valid unless they are properly executed according the state probate rules. Simply filling out an online form is not enough to create a valid will. Each state has specific rules for determining whether or not a will has been validly executed. For the most part, these rules require that the will be in writing, signed and witnessed by two people. These requirements focus on the physical – physical documents and the physical presence of witnesses. The writing and signature requirements generally mean that a person must print out the online will and sign a hard copy, and the witnessing also needs to be done in person. States have begun to consider moving toward electronic wills, spurred on mostly by the new and demanding conditions of physical distancing brought on by the COVID-19 pandemic. Some states adopted temporary emergency orders authorizing electronic wills during the first phases of the pandemic, but most states have yet to fully adopt electronic wills or remote witnessing. Something to check, then, when considering an online will is whether or not the program or template is state specific and clearly explains what further steps will be needed to validly execute the will after the document has been prepared online. Covering the what-ifsSomething else worth investigating for those considering online wills is what kind of questionnaire the program provides. Estate planning, as I tell my students all the time, is about matching up your things with the people you want to inherit them. Good will-drafting is also, however, about imagining worst-case scenarios, thinking three steps ahead and writing contingency plans into the document. Who gets that ugly landscape painting if Aunt Bridget is already dead when you die? Does Cousin Jamal get any replacement value if the stock he was supposed to receive through the will was sold? What happens if the family members who were supposed to inherit the bulk of the estate all die in an unexpected avalanche during a ski vacation? Accordingly, those in the market for an online will should make sure that the online program offers a detailed questionnaire to guide them through the strange and sometimes gruesome world of unlikely but incredibly important "what-if" scenarios. Things can get complicatedFinally, while it might be obvious, online will templates are best for simple estates. If you have real property in more than one state, if you have a complicated family structure involving multiple marriages and sets of children, if you have a family business that will be passed down – in all these situations you might consider consulting an estate planner. That person can give you advice on how to deal with these more legally complicated and financially sophisticated situations that online will templates are not necessarily set up to accommodate. [Over 140,000 readers rely on The Conversation's newsletters to understand the world. Sign up today.] Ultimately, then, you may need to get out of bed to have your will witnessed, and you may need to leave your house to consult with a lawyer about complicated assets. But the good news is that with online will-writing programs you can do a lot of the groundwork at home, drinking coffee in your pajamas.  Allison Anna Tait owns a small number of shares in Legal Zoom |
| When researchers don't have the proteins they need, they can get AI to 'hallucinate' new structures Posted: 05 Jan 2022 05:47 AM PST  All living organisms use proteins, which encompass a vast number of complex molecules. They perform a wide array of functions, from allowing plants to use solar energy for oxygen production to helping your immune system fight against pathogens to letting your muscles perform physical work. Many drugs are also based on proteins. For many areas of biomedical research and drug development, however, there are no natural proteins that can serve as suitable starting points to build new proteins. Researchers designing new drugs to prevent COVID-19 infection, or developing proteins that can turn genes on or off or turn cells into computers, had to create new proteins from scratch. This process of de novo protein design can be difficult to get right. Protein engineers like me have been trying to figure out ways to more efficiently and accurately design new proteins with the properties we need. Luckily, a form of artificial intelligence called deep learning may provide an elegant way to create proteins that did not exist previously – hallucination. Designing proteins from scratchProteins are made up of hundreds to thousands of smaller building blocks called amino acids. These amino acids are connected to one another in long chains that fold up to form a protein. The order in which these amino acids are connected to one another determines each protein's unique structure and function.  The biggest challenge protein engineers face when designing new proteins is coming up with a protein structure that will perform a desired function. To get around this problem, researchers typically create design templates based on naturally occurring proteins with a similar function. These templates have instructions on how to create the unique folds of each particular protein. However, because a template must be created for each individual fold, this strategy is time-consuming, labor-intensive and limited by what proteins are available in nature. Over the past few years, various research groups, including the lab I work in, have developed a number of dedicated deep neural networks – computer programs that use multiple processing layers to "learn" from input data to make predictions about a desired output. When the desired output is a new protein, millions of parameters describing different facets of a protein are put into the network. What's predicted is a randomly chosen sequence of amino acids mapped onto the most probable 3D structure that sequence would take. Network predictions for a random amino acid sequence are blurry, meaning the final structure of the protein is not very clear-cut, while both naturally occurring proteins and proteins built from scratch produce much more well-defined protein structures. Hallucinating new proteinsThese observations hint at one way that new proteins can be generated from scratch – by tweaking random inputs to the network until predictions yield a well-defined structure. The protein generation method my colleagues and I developed is conceptually similar to computer vision methods such as Google's DeepDream, which finds and enhances patterns in images. These methods work by taking networks trained to recognize human faces or other patterns in images, like the shape of an animal or an object, and inverting them so that they learn to recognize these patterns where they don't exist. In DeepDream, for example, the network is given arbitrary input images that are adjusted until the network can recognize a face or some other shape in the image. While the final image doesn't look much like a face to a person looking at it, it would to the neural network. The products of this technique are often referred to as hallucinations, and this is what we call our designed proteins, too. Our method starts by passing a random amino acid sequence through a deep neural network. The resulting predictions are initially blurry, with unclear structures, as expected for random sequences. Next, we introduce a mutation that changes one amino acid in the chain into a different one and pass this new sequence through the network again. If this change gives the protein a more defined structure, then we keep the amino acid and we introduce another mutation into the sequence. With each repetition of this process, the proteins get closer and closer to the real shape they would take if they were produced in nature. Thousands of repetitions are required to create a brand-new protein. Using this process, we generated 2,000 new protein sequences predicted to fold into well-defined structures. Of these, we selected over 100 that were the most distinct in shape to physically recreate in the lab. Finally, we chose three of the top candidates for detailed analysis and confirmed that they were close matches to the shapes predicted by our hallucinated models. Why hallucinate new proteins?Our hallucination approach greatly simplifies the protein design pipeline. By eliminating the need for templates, researchers can directly focus on creating a protein based on desired functions and let the network take care of figuring out the structure for them. Our work opens up multiple avenues for researchers to explore. Our lab is currently investigating how to best use this hallucination approach to generate even more specificity in the function of designed proteins. Our approach can also be readily extended to design new proteins using other recently developed deep neural networks. The potential applications of de novo proteins are vast. With deep neural networks, researchers will be able to create even more proteins that can break down plastics to reduce environmental pollution, identify and respond to unhealthy cells and improve vaccines against existing and new pathogens – just to name a few. [Like what you've read? Want more? Sign up for The Conversation's daily newsletter.]  Ivan Anishchenko receives funding from NSF (grant DBI 1937533) and NIAID (Federal Contract HHSN272201700059C). |
| How cybercriminals turn paper checks stolen from mailboxes into bitcoin Posted: 05 Jan 2022 05:47 AM PST  While cybercrime gets a lot of attention from law enforcement and the media these days, I've been documenting a less high-tech threat emerging in recent months: a surge in stolen checks. Criminals are increasingly targeting U.S. Postal Service and personal mailboxes to pilfer filled-out checks and sell them over the internet using social media platforms. The buyers then alter the payee and amount listed on the checks to rob victims' bank accounts of thousands of dollars. While the banks themselves typically bear the financial burden and reimburse targeted accounts, criminals can use the checks to steal victims' identities, which can have severe consequences. I founded and now direct Georgia State University's Evidence Based Cybersecurity Research Group, which is aimed at learning what works and what doesn't in preventing cybercrime. For the past two years, we've been surveilling 60 black market communication channels on the internet to learn more about the online fraud ecosystem and gather data on it in a systematic way in order to spot trends. One thing we didn't expect to see was a surge in purloined checks. An old threat returnsIn general, bank check theft is a type of fraud that involves the stealing and unauthorized cashing of a check. It's hardly a new phenomenon. Criminals were committing check fraud as soon as the first modern checks were cut in the 18th century in England – and the authorities were already looking for ways to prevent it. While there's little historical data on this type of fraud, we do know it became particularly problematic in the 1990s as the internet made finding willing buyers of illicit items easier than ever. For example, financial institutions estimated they lost about US$1 billion to check fraud from April 1996 to September 1997. But what may seem a little surprising is that its resurgence now at a time when the vast majority of transactions are conducted electronically and check use continues to wane. What check fraud looks likeBroadly speaking, the check scams we've been tracking look something like this: Someone breaks into a mailbox that stores letters waiting to be sent and grabs some of them in hopes they'll contain a check that's been filled in. Often, the crime scene where the theft occurs is the victim's own mailbox, but it can also be one of those blue USPS boxes you pass on the street. Criminals can access those with a stolen or copied mailbox key, which we have seen on sale for as much as $1,000.  Thieves may deposit or cash the checks themselves or sell them on to others via a marketplace of illicit items, such as fake IDs and credit cards. Prices are typically $175 for personal checks and $250 for business ones – payable in bitcoin – but always negotiable and cheaper in bulk, based on our observations and direct interactions with the sellers. Buyers then use nail polish remover to erase the intended payee's name and the amount displayed on the check, replacing those details with their own preferred payee – such as a retailer – and amount, usually a lot higher than the original check. A buyer might also simply cash the check at a location like Walmart using a fake ID. In some cases we believe criminals are using the checks to steal the victim's identity by using their name and address to manufacture fake driver's licenses, passports and other legal documents. Upon taking over someone's identity, a criminal may use it to submit false applications for loans and credit cards, access the victim's bank accounts and engage in other types of online fraud. Tracking black market chat roomsTo better understand how cybercriminals operate, my team of graduate students began monitoring 60 online chat room channels where we knew people were trafficking in fraudulent documents. Examples of these types of channels are group chats on messaging apps like WhatsApp, ICQ and Telegram, in which users post pictures of items they wish to sell. Some of the channels we are monitoring are public, while others required an invitation, which we managed to procure.  After we noticed a rise in stolen checks on sale, we began systematically gathering data from those channels about six months ago in order to track the trend. We downloaded the images, coded them and then aggregated the data so we could spot trends in what was being sold. In our observations, we came across an average of 1,325 stolen checks being sold every week in October 2021, up from 634 per week in September and 409 in August. Although little historical data on this practice exists, a one-week pilot study we conducted in October 2020 places these numbers in some perspective. Back then, we observed only 158 stolen checks during that period. Furthermore, these figures likely only represent a small fraction of the number of checks actually being stolen and sold. We focused on only 60 markets, when in fact there are thousands currently active. In dollar amounts, we found that the face value of the checks, as written, was $11.6 million in all of October and $10.2 million in September. But again, these values likely represent a small share of the actual amount of money being stolen from victims because criminals often rewrite the checks for much higher amounts. Using the victims addresses, which appeared on the left top corner of the checks, and focusing on the data we collected in the month of October 2021, we found New York, Florida, Texas and California were the top sources.  How to protect yourselfThe best advice I can give consumers who want to avoid falling victim to these schemes is to avoid mailing checks, if you can. Bank checking accounts usually offer customers the option to send money electronically, whether to a friend or a company, for free. And there are many apps and other services that allow you to make digital payments from bank accounts or via credit card. While there are risks with these methods as well, in general they are a lot safer than writing a check and sending it in the mail. Still, some types of businesses may require a physical check for payment, such as landlords, utilities and insurance companies. Moreover, as a matter of personal preference, some people – myself included – prefer to pay their bills using checks rather than other methods of payment. To avoid the risk, I make sure to drop off all my letters containing checks inside my local post office. That's generally your best bet for keeping them out of the hands of criminals and ensuring they reach their intended destination. The United States Postal Inspection Service, the agency responsible for preventing mail theft, also offers tips to stay protected. As for enforcement, the inspection service works with the police and others to crack down on mail-related crime. These efforts result in the arrest of thousands of mail and packages thieves every year. However, for every arrest, there are many more criminals who go undetected. [Over 140,000 readers rely on The Conversation's newsletters to understand the world. Sign up today.] And when we informed officials of our findings, they were also surprised by what we discovered but planned to step up monitoring of these types of black market communication channels. Our research suggests much more systematic data on this type of fraud is needed in order to better understand how it works, crack down on the activity and prevent it from occurring in the first place.  David Maimon receives funding from the National Science Foundation, Minerva, Department of Homeland Security, and the Federal Reserve Bank. |
| Posted: 05 Jan 2022 05:47 AM PST Every disaster movie seems to open with a scientist being ignored. "Don't Look Up" is no exception – in fact, people ignoring or flat out denying scientific evidence is the point. Leonardo DiCaprio and Jennifer Lawrence play astronomers who make a literally Earth-shattering discovery and then try to persuade the president to take action to save humanity. It's a satire that explores how individuals, scientists, the media and politicians respond when faced with scientific facts that are uncomfortable, threatening and inconvenient. The movie is an allegory for climate change, showing how those with the power to do something about global warming willfully avoid taking action and how those with vested interests can mislead the public. But it also reflects science denial more broadly, including what the world has been seeing with COVID-19. The most important difference between the film's premise and humanity's actual looming crisis is that while individuals may be powerless against a comet, everyone can act decisively to stop fueling climate change. Knowing the myths that feed science denial can help. As research psychologists and the authors of "Science Denial: Why It Happens and What to Do About It", we recognize these aspects of science denial all too well. Myth #1: We can't act unless the science is 100% certainThe first question President Orlean (Meryl Streep) asks the scientists after they explain that a comet is on a collision course with Earth is, "So how certain is this?" Learning that the certitude is 99.78%, the president's chief of staff (Jonah Hill) responds with relief: "Oh great, so it's not 100%!" Government scientist Teddy Oglethorpe (Rob Morgan) replies, "Scientists never like to say 100%." This reluctance to claim 100% certainty is a strength of science. Even when the evidence points clearly in one direction, scientists keep exploring to learn more. At the same time, they recognize overwhelming evidence and act on it. The evidence is overwhelming that Earth's climate is changing in dangerous ways because of human activities, particularly the burning of fossil fuels, and it has been overwhelming for many years. When politicians take a "let's wait and see" attitude toward climate change (or "sit tight and assess," as the movie puts it), suggesting they need more evidence before taking any action, it's often a form of science denial. Myth #2: Disturbing realities as described by scientists are too difficult for the public to acceptThe title phrase, "Don't Look Up," portrays this psychological assumption and how some politicians conveniently use it as an excuse for inaction while promoting their own interests. Anxiety is a growing and understandable psychological response to climate change. Research shows there are strategies people can use to effectively cope with climate anxiety, such as becoming better informed and talking about the problem with others. This gives individuals a way to manage anxiety while at the same time taking actions to lower the risks. A 2021 international study found that 80% of individuals are indeed willing to make changes in how they live and work to help reduce the effects of climate change. Myth #3: Technology will save us, so we don't have to actOften, individuals want to believe in an outcome they prefer, rather than confront reality known to be true, a response that psychologists call motivated reasoning. For example, belief that a single technological solution, such as carbon capture, will fix the climate crisis without the need for change in policies, lifestyles and practices may be more grounded in hope than reality. Technology can help reduce our impact on the climate; however, research suggests advances are unlikely to come quickly enough. Hoping for such solutions diverts attention from significant changes needed in the way we work, live and play, and is a form of science denial. Myth #4: The economy is more important than anything, including impending crises predicted by scienceTaking action to slow climate change will be expensive, but not acting has extraordinary costs – in lives lost as well as property. Consider the costs of recent Western wildfires. Boulder County, Colorado, lost nearly 1,000 homes to a fire on Dec. 30, 2021, after a hot, dry summer and fall and almost no rain or snow. A study of California's fires in 2018 – another hot, dry year – when the town of Paradise burned, estimated the damage, including health costs and economic disruption, at about $148.5 billion.  When people say we can't take action because action is expensive, they are in denial of the cost of inaction. Myth #5: Our actions should always align with our social identity groupIn a politically polarized society, individuals may feel pressured to make decisions based on what their social group believes. In the case of beliefs about science, this can have dire consequences – as the world has seen with the COVID-19 pandemic. In the U.S. alone, more than 825,000 people with COVID-19 have died while powerful identity groups actively discouraged people from getting vaccines that could protect them. Viruses are oblivious to political affiliation, and so is the changing climate. Rising global temperatures, worsening storms and sea level rise will affect everyone in harm's way, regardless of the person's social group. How to combat science denial – and climate changeA comet headed for Earth might leave little for individuals to do, but this is not the case with climate change. People can change their own practices to reduce carbon emissions and, importantly, pressure leaders in government, business and industry to take actions, such as reducing fossil fuel use, converting to cleaner energy and changing agricultural practices to reduce emissions. In our book, we discuss steps that individuals, educators, science communicators and policymakers can take to confront the science denial that prevents moving forward on this looming issue. For example:
As scholars who work to help people make sound decisions about complex problems, we encourage people to consume news and science information from sources outside their own identity group. Break out of your social bubble and listen to and talk with others. Look up.  Gale Sinatra has received funding from the National Science Foundation (NSF), the Social Sciences and Humanities Research Council (SSHRC) of Canada, and Mattel Children's Foundation. Barbara K. Hofer has received research funding from the National Science Foundation and Vermont EPSCOR. |
| Posted: 05 Jan 2022 05:45 AM PST  A quick walk down the drink aisle of any corner store reveals the incredible ingenuity of food scientists in search of sweet flavors. In some drinks you'll find sugar. A diet soda might have an artificial or natural low-calorie sweetener. And found in nearly everything else is high fructose corn syrup, the king of U.S. sweetness. I am a chemist who studies compounds found in nature, and I am also a lover of food. With confusing food labels claiming foods and beverages to be diet, zero-sugar or with "no artificial sweeteners," it can be confusing to know exactly what you are consuming. So what are these sweet molecules? How can cane sugar and artificial sweeteners produce such similar flavors? First, it is helpful to understand how taste buds work.  Taste buds and chemistryThe "taste map" – the idea that you taste different flavors on different parts of your tongue – is far from the truth. People are able to taste all flavors anywhere there are taste buds. So what's a taste bud? Taste buds are areas on your tongue that contain dozens of taste receptor cells. These cells can detect the five flavors – sweet, sour, salty, bitter and umami. When you eat, food molecules are dissolved in saliva and then washed across the taste buds, where they bind to the different taste receptor cells. Only molecules with certain shapes can bind to certain receptors, and this produces the perception of different flavors. Molecules that taste sweet bind to specific proteins on the taste receptor cells called G-proteins. When a molecule binds these G-proteins, it triggers a series of signals that are sent to the brain where it is interpreted as sweet.  Natural sugarsNatural sugars are types of carbohydrates known as saccharides that are made of carbon, oxygen and hydrogen. You can imagine sugars as rings of carbon atoms with pairs of oxygen and hydrogen attached to the outside of the rings. The oxygen and hydrogen groups are what make sugar sticky to the touch. They behave like Velcro, sticking to the oxygen and hydrogen pairs on other sugar molecules. The simplest sugars are single-molecule sugars called monosaccharides. You've probably heard of some of these. Glucose is the most basic sugar and is mostly made by plants. Fructose is a sugar from fruit. Galactose is a sugar in milk. Table sugar – or sucrose, which comes from sugar cane – is an example of a dissacharide, a compound made of two monosaccharides. Sucrose is formed when a glucose molecule and a fructose molecule join together. Other common dissacharides are lactose from milk and maltose, which comes grains. When these sugars are eaten, the body processes each of them slightly differently. But eventually they are broken down into molecules that your body converts into energy. The amount of energy from sugar – and all food – is measured in calories.  High fructose corn syrupHigh fructose corn syrup is a staple of U.S. foods, and this hybrid sugar sweetener needs a category all on its own. High fructose corn syrup is made from corn starch – the main carbohydrate found in corn. Corn starch is made of thousands of glucose molecules bonded together. At an industrial scale, the starch is broken into individual glucose molecules using enzymes. This glucose is then treated with a second enzyme to convert some of it into fructose. Generally, high fructose corn syrup is roughly 42%-55% fructose. This blend is sweet and cheap to produce but has a high calorie content. As with other natural sugars, too much high fructose corn syrup is bad for your health. And since most processed foods and drinks are packed full of the stuff, it is easy to consume too much.  Natural nonsugar sweetenersThe second category of sweeteners could be defined as natural nonsugar sweeteners. These are food additives such as stevia and monk fruit, as well as natural sugar alcohols. These molecules aren't sugars, but they can still bind to the sweet receptors and therefore taste sweet. Stevia is a molecule that comes from the leaves of the Stevia redaudiana plant. It contains "sweet" molecules that are much larger than most sugars and have three glucose molecules attached to them. These molecules are 30 to 150 times sweeter than glucose itself. The sweet molecules from monk fruit are similar to stevia and 250 times sweeter than glucose. The human body has a really hard time breaking down both stevia and monk fruit. So even though they're both really sweet, you don't get any calories from eating them. Sugar alcohols, like sorbital, for example, are not as sweet as sucrose. They can be found in a variety of foods, including pineapples, mushrooms, carrots and seaweed, and are often added to diet drinks, sugar-free chewing gum and many other foods and drinks. Sugar alcohols are made of chains of carbon atoms instead of circles like normal sugars. While they are composed of the same atoms as the sugars, sugar alcohols are not absorbed well by the body so they are considered low-calorie sweeteners.  Artificial sweetenersThe third way to make something sweet is to add artificial sweeteners. These chemicals are produced in labs and factories and are not found in nature. Like all things that taste sweet, they do so because they can bind to certain receptors in taste buds. [Over 140,000 readers rely on The Conversation's newsletters to understand the world. Sign up today.] So far, the U.S. Food and Drug Administration has approved six artificial sweeteners. The most well known are probably saccharin, aspartame and sucralose – better known as Splenda. Artificial sweeteners all have different chemical formulas. Some resemble natural sugars while others are radically different. They are usually many times sweeter than sugar – saccharin is an incredible 200 to 700 times sweeter than table sugar – and some of them are hard for the body to break down. While a sweet dessert may be a simple pleasure for many, the chemistry of how your taste buds perceive sweetness is not so simple. Only molecules with the perfect combination of atoms taste sweet, but bodies deal with each of these molecules differently when it comes to calories.  Kristine Nolin does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment. |
| You are subscribed to email updates from Home – The Conversation. To stop receiving these emails, you may unsubscribe now. | Email delivery powered by Google |
| Google, 1600 Amphitheatre Parkway, Mountain View, CA 94043, United States | |
.jpg#/media/File:Stevia_rebaudiana_(potted_plant).jpg){kind=link}
No comments:
Post a Comment