But new ideas come to light, new paradigms emerge, and new tasks are taken on board in the endless churn and change that is the Internet. And so it is for us. As of today we’re suspending regular publication of new posts here on Britannica Blog. We’re at work on new ways to inform and engage you at Britannica.com, and that will command our energies in 2014.

The blog and all of the posts that have appeared since the beginning will stay right here for, we hope, your reading pleasure. Come whenever you like to search, browse, and enjoy. Or visit our complete archive here.

Thanks to all the people who have been with us along the way—readers, contributors, and friends. You’ve made it rewarding and fun.

A circumscribing line of setae around this twig make a difficult wall to pass as an ant. Credit: Phil Torres

Note the protective ‘walls’ of hairs above the forming cocoon. Credit: Phil Torres

Many moths incorporate the setae (hairs) of the caterpillar into the cocoon in some way—often in the form of a weaving them with silk into the protective case around the pupa.

But the method used by this [unidentified] species takes some serious planning.

At the bottom, you get the forming cocoon and pupa, with the caterpillar still inside. But as you go up the twig you find multiple ‘walls’ constructed out of the caterpillar’s hairs all woven together to prevent predators like ants from climbing down.

The process of making this would have been truly something to watch, as the caterpillar literally takes the hair off its back and carefully weaves them together using the silk gland located just below the mouth.

As I figured out what the hairs were doing, I literally said aloud, to myself, “How are there so many cool things here?!” The Amazon never ceases to amaze me with the unique adaptations we find out here every day. Seriously.

Elephant Poaching

No one knows for sure how many elephants exist in the wild in 2013. Even the agencies that monitor them will not issue official population estimates and will venture unofficial counts only with the greatest of trepidation. Some projections, however, suggest that the rapid surge in poaching could lead to the extinction of the African species within a decade. Fueling that threat is a brisk escalation in the ivory trade in Asia.

In the Democratic Republic of the Congo’s Garamba National Park a group of soldiers and park rangers in July 2012 examine the remains of an African elephant that was slaughtered by poachers for its tusks. Credit: Tyler Hicks—The New York Times/Redux

Counting Invisible Giants

Estimates do exist for the three species. The African savanna, or bush, elephant (Loxodonta africana), is the largest living land animal, with males, known as bulls, weighing up to nine tons each. Its cousins, the African forest elephant (L. cyclotis)—considered by some authorities to be a subspecies—and the Asian elephant (Elephas maximus)—comprising three subspecies—are not much smaller. A comprehensive 2013 report compiled by the United Nations Environment Programme (UNEP), the International Union for the Conservation of Nature (IUCN), the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and the wildlife-trade-monitoring network TRAFFIC suggested a combined population of 420,000–650,000 African savanna and forest elephants spread across 35–38 African countries. Some 80% of the population—comprising solely savanna elephants—is concentrated in southern and eastern African countries, with 50% living in Botswana, Tanzania, and Zimbabwe. Central Africa and western Africa, home to both forest and savanna elephants, host the remaining 18% and 2%, respectively.

A herd of African elephants and their calves walk across the African savannah in 2008. Credit: © Photos.com/Jupiterimages Corporation

The IUCN estimates that 40,000–50,000 Asian elephants are spread across 13 countries in Asia: Bangladesh, Bhutan, Cambodia, China, India, Indonesia, Laos, Malaysia, Myanmar (Burma), Nepal, Sri Lanka, Thailand, and Vietnam. India is likely home to more than 50% of all Asian elephants. There is still no reliable mechanism for keeping tabs on one of the most conspicuous residents of the planet. Data are difficult to gather on both continents owing to the political volatility of some regions and to the expense of aerial and ground surveys; unsystematic data collection further skews the projections.

Blood Ivory

The price of that unknown is exacted in blood and gore. Tusks, the enlarged incisor teeth that are the raw material for worked ivory, are normally sawed off at the base by poachers, often while the elephant is not yet dead. The valued part of the tusk comprises dentin covered by cementum. The dentin component is what is used to create the often-intricate ivory confections demanded by the Asian market; the cementum is usually discarded.

The African elephant, at greatest risk from the uptick in ivory poaching, is protected in only 20% of its range. That leaves a huge proportion of the pachyderms unprotected even by the porous boundaries of national parks and other conservation areas. These populations—which oftentimes overlap areas inhabited by humans—are thus harder to monitor. Populations that cannot be monitored cannot be defended. Despite their physical size and strength, elephants are in increasing need of protection. Even the armed guards who patrol some national parks are often no match for the heavy artillery and stealthy maneuvering of poachers harvesting ivory in central and eastern Africa at the behest of military leaders and warlords, who sell the valuable tusks to fund their operations. Park rangers themselves have been implicated in poaching incidents.

Confiscated black market elephant tusks await disposal in 2013. Credit: Born Free USA

The majority of ivory, though, is thought to be culled by local hunters, who sell to criminal syndicates via a variety of murky channels. They may also harvest flesh for the bushmeat trade. A 2011 report estimated that some 17,000 elephants had been killed in regions surveyed by the CITES Monitoring the Illegal Killing of Elephants (MIKE) program alone. That figure then constituted more than 7% of the total; perhaps 8,000 more are thought to have been taken elsewhere that year. In western Africa, Cameroon, the Central African Republic, Chad, and Gabon have faced particular threats; Cameroon saw major slaughters in 2012, as did Chad in 2013. Poaching is at its most intense in central Africa. About 60% of the forest elephants that remained in 2002 have since been killed. Even southern and eastern Africa, where savanna elephant populations are robust, have seen increased elephant deaths. After a period of respite, major slaughters occurred in Kenya in 2013.

The trade in Asian elephant ivory is less extensive, mainly because only some Asian elephants have tusks, and when present, they are far smaller than those wielded by their African cousins. Nonetheless, Asian elephants are also killed for their ivory. In Myanmar wild baby elephants are captured for sale as performance animals in Thailand. Additionally, about 13,000 Asian elephants are thought to be kept in captivity on the Asian continent, employed either as entertainment or as service animals. It is unknown how many of that number were captured from the wild.

Eastern Demand

Though the elephant slaughter itself is largely carried out by African nationals, the market driving the recent intensification of the quest for ivory is overwhelmingly Asian. According to the IUCN, the illegal ivory market is thought to have tripled since 1998 and doubled since 2007. Seizures of major shipments of ivory to Asian markets have doubled since 2009. The years 2009, 2010, and 2011 saw among the highest volumes of ivory seized since monitoring began. Buyers in China, the primary market for illegal ivory, along with those in Thailand, Japan, and the Philippines, have increasingly clamoured for sculptures and trinkets carved of the precious substance.

Officials at a customs warehouse in Osaka, Japan, in 2007 examine 2.8 tons of elephant tusks that were seized after having been illegally smuggled into that country. Credit: AFP/Getty Images

In China ivory objects—from Buddhist devotional tokens to elaborate statues—have recently become attainable gifts and status symbols among the booming middle class. The country is thought to provide a market for upwards of 70% of illegal ivory traded annually. Thailand is another major market; its legal trade has provided cover for illegal ivory. There Buddhist trinkets carved of ivory are in high demand. Buddhist religious tradition holds that a white elephant entered the mother of the Buddha when he was conceived, making the material of particular significance. The Philippines, once perceived as a mere conduit for ivory, akin to Malaysia and Vietnam, is thought to be home to a flourishing ivory market as well.

Icy telescope “reads” ancient message from distant universe

The surprise, after 15 years of planning and development, was that the ghostly particles from outer space were so easy to see. After all, “The neutrino is a tough particle to deal with,” says Francis Halzen, principal investigator of IceCube at the University of Wisconsin–Madison, where the detection was made.

Here’s the track of the most powerful neutrino ever observed: estimated energy 1.14 million-billion electron volts. Each balloon shows the activation of a single detector in a block of frozen water at the IceCube Neutrino Observatory at the South Pole. IceCube physicists named the lil’ newt Ernie. Courtesy The Why Files/Courtesy IceCube Collaboration

Scientists have produced neutrinos in laboratories, measured them outside nuclear reactors, and detected them streaming from the Sun.

In November, in the journal Science, the IceCube Collaboration reported the detection of 28 high-energy neutrinos, including energetic Ernie at 1.14 (see portrait at right). These neutrinos were so energetic that they must have come from outside the solar system.

Because many of them did not line up with the plane of our galaxy, they likely came from beyond the Milky Way.

But what’s a neutrino, and why should we care? For starters, they are elusive. Neutrinos almost never interact with matter. That makes them almost invisible. Billions of neutrinos have passed through your body since you clicked over to this page.

In 1930, physicist Wolfgang Pauli, who first proposed the neutrino to balance an equation, said, “I have done a terrible thing. I have postulated a particle that cannot be detected.”

His postulation was, as they say, close enough for horseshoes and hand grenades. But a vanishingly small percentage of neutrinos do strike other particles, creating a particle called the muon that is much easier to detect.

But that vice is also a virtue. That failure to interact allows neutrinos to travel unscathed from the most distant reaches of the universe, where they are (presumably) born in catastrophic collisions or titanic explosions—or something even weirder.

NEUTRINOS MAKE MUONS AND MUONS MAKE BLUE LIGHT. ICE-BOUND DETECTORS SEE LIGHT, SIGNAL COMPUTERS THAT POINT AT [THE] NEUTRINO SOURCE.

Searching for the source

Finding that something is the ultimate goal of IceCube, an upside down telescope at the South Pole, where scientists have converted a cubic kilometer of pure ice into the world’s largest astrophysics experiment.

The IceCube Neutrino Observatory was completed in December, 2010. Courtesy The Why Files/Courtesy Chad Carpenter, IceCube/NSF

The project is headquartered at Madison and funded by the National Science Foundation. The IceCube detector was completed in December 2010 after seven years of construction. It was built on time and on budget and in its first two years has exceeded design specifications.

The IceCube collaboration is interested in high-energy neutrinos, rather than the lower-energy type created in our Sun. “This is the first indication of very high-energy neutrinos coming from outside our solar system, with energies more than one million times those observed in 1987 in connection with a supernova,” says Halzen. “It is gratifying to finally see what we have been looking for. This is the dawn of a new age of astronomy.”

The bad news is that it’s too soon to know any specifics about the source of these ultra-high energy particles, which must be something amazingly energetic.

The IceCube Laboratory at the Amundsen-Scott South Pole Station in Antarctica is the world’s largest neutrino detector. Data processing—removing boring signals—happens in near real-time here, and interesting neutrino events go to the IceCube Collaboration at UW-Madison for further study. Courtesy The Why Files/Courtesy Sven Lidstrom, IceCube/NSF, March 2012

Dealing with data

At IceCube, a digital data dance begins the moment a photon of light triggers eight spherical detectors deep in the ice, and a digital notice is sent to the surface. The computers weed through gobs of data: From 6,000 “events” every second, it sifts out one neutrino every six minutes or so.

But most of those neutrinos come from the Sun…so further winnowing leaves about one high-energy neutrino per month, says Halzen.

To see a neutrino, scientists generally look for the muons that are created after the rare collision between a neutrino and a particle in the target. Because such collisions are rare, bigger detectors rule.

In the 1960s and ’70s, scientists went to great lengths (and depths) to find neutrinos, burying large masses of water, oil, or iron plates deep underground, where the target was sheltered from spurious, lower-energy signals.

In 1987, Halzen had a brainstorm. Why not use the Antarctic ice-cap as your target, and freeze detectors inside an essentially unlimited mass of ice?

It was an unlikely scheme: A telescope that looked downward. A gadget designed to see things that are phenomenally shy. And an astrophysics experiment built around a target of unknown purity.

“Usually you study the material first,” says Halzen, “but we had no access to our material. We had to take what was given to us by nature.”

Courtesy The Why Files/Courtesy Dan Brennan/University of Wisconsin–Madison

The blue light created by muons will only travel eight meters in distilled water, but the muons must travel much further to be seen by at least eight IceCube detectors. Eight is the borderline that makes an event energetic enough to be worth further study.

In the ultra-pure ice-cap, muons can travel 100 meters or more. “You cannot filter water this clear,” says Halzen. “It’s the clearest solid in the universe, as far as we know.”

Easy does it

Ironically, after all the difficult, expensive, and dangerous work of drilling holes and setting globes in the ice, identifying the highest-energy neutrinos turns out to be eyeball-easy. “I have looked at thousands of neutrino tracks, but when I see one of these tracks, there is no doubt, none,” says Halzen. “It’s a needle in a haystack, sure, but these events are so spectacular that it’s a needle that is sticking out of the haystack.”

While an intriguing map shows where in the universe these neutrinos originated, it’s too soon to pinpoint the sources, Halzen says. But he intimates that could quickly change. “Now that we know what we are looking for, we can expand the search and find more events.”

– David J. Tenenbaum

Terry Devitt, editor; S.V. Medaris, designer/illustrator; Yilang Peng, project assistant; David J. Tenenbaum, feature writer; Amy Toburen, content development executive

Related Why Files
Old and distant galaxy
Boasting about the boson
Chasing neutrinos at the South Pole
Neutrinos: Seeing the Invisible Particle

Bibliography
1. “Evidence for High-Energy Extraterrestrial Neutrinos at the IceCube Detector,” IceCube Collaboration, Science 22 Nov. 2013. ↩
2. The IceCube Project ↩
3. What’s a Neutrino? ↩
4. All About Neutrinos ↩
5. Why Do Neutrinos Matter? ↩

Paper money from around the world. Credit: Peter Dazeley—Stone/Getty Images

Since 1938 Britannica’s annual Book of the Year has offered in-depth coverage of the events of the previous year. While the 75th anniversary edition of the book won’t appear in print for several months, some of its outstanding content is already available online. This week, the Britannica Blog features this article by Adam B. Levine on the rise of the virtual currency Bitcoin.

Bitcoin: The Rise of Virtual Currency

The possibility of a globally recognized virtual or digital currency seemed its closest ever in 2013 as Bitcoin, a cryptographically secured monetary unit (or crypto-currency) developed in the wake of the 2008 financial crisis, gained in popularity—and value—and began to make inroads into mainstream financial transactions. Speculators were blamed for some of the incredible volatility in the value of a Bitcoin, which ranged from $0.05 in July 2010 to $13 in early 2013 before spiking to $266 in April, dropping to about $60, and then soaring above $1,000 in late November. Meanwhile, some traditional vendors and online marketplaces began to accept Bitcoin as a legitimate form of electronic payment for goods and services.

The increasing use of virtual currency became more evident in October 2013 when the FBI announced that it had shut down the underground Web site Silk Road—an anonymous online marketplace used for illegal drug deals, money laundering, and other criminal activities—which accepted only Bitcoins as payment for all transactions. The U.S. government also seized millions of dollars worth of Bitcoins being held on the Silk Road computers. This triggered U.S. Senate hearings in November on the future of Bitcoin and other virtual currencies, which even the FBI acknowledged “offer legitimate financial services.”

Background

On Nov. 1, 2008, an unidentified individual or group using the pseudonym Satoshi Nakamoto released, with little fanfare, what would become known as the Satoshi White Paper. This document, titled Bitcoin: A Peer-to-Peer Electronic Cash System, detailed a protocol for a new kind of distributed money. It was a new variation on an old theme, following in the footsteps of DigiCash, e-gold, and other digital currencies.

At its core Bitcoin is decentralized “digital cash” that was designed as both a payment network and a unit of account native to the Internet. Bitcoin transactions, like those involving cash, are person-to-person deals requiring no bank or money transmitter to facilitate. This means that they are irreversible, are very fast, and have very low or no costs. Unlike the procedure in a cash transaction, however, an individual does not need to be standing next to a person to transfer Bitcoins. Users install free open-source “wallet” software on their computers or mobile devices, a function that allows them to send and receive Bitcoins to and from anyone else connected to the Internet.

For the past century or more, control and caretaking of money has been left to national or regional governments. Rather than being governed by groups of people, however, Bitcoin’s rules are codified in its cryptographically secured protocol. Anyone who dedicates specialized computer hardware with enough computational power (measured in “hashes” per second) to help implement these rules can do so and be rewarded for it. The monetary fundamentals, such as how much of the currency should be issued and on what schedule, were decided before the first Bitcoin even came into existence. Irrevocable instructions provide an accurate road map for Bitcoin through the year 2140. Because anyone can participate, the protocol includes a number of “self-adjusting mechanisms” to keep the system running as close to the ideal as possible.

The virtual transfer of Bitcoins relies on an open and transparent global ledger that keeps track of the creation and ownership of every Bitcoin ever produced. A copy of this ledger is stored on each participating computer, a safeguard that makes the system very resistant to disruptions or distortions even should such occurrences have an impact on a large proportion of total Bitcoin users. Verification of transfers is completely automated, and each installation of wallet software individually and independently verifies that all other transactions are following the rules by using hard to falsify but easy to verify public-key cryptography.

Public-Key Cryptography

Public-key cryptography uses a digital “keypair” involving a private key and one or more public addresses. The public address can be thought of as a locked mailbox: anyone can use it to leave something for the owner of the box, but it requires a specific key (the private key) to access the contents left by others.

When a user creates a new wallet, a public/private keypair is automatically generated. To receive Bitcoins a person distributes an individual public address or creates a new one. An unlimited number of public addresses may be generated, each controlled by the same private key, and other users can transmit Bitcoins to the person who controls that key by using any one of those addresses. A user can then transmit control of Bitcoins from his or her wallet to someone else, as in a purchase, by using the private key to automatically sign a new transaction. The owner’s signature serves to confirm the address from which the Bitcoins will be sent, and every client on the network will eventually verify that the signature is valid. Each Bitcoin can itself be effortlessly divided to 0.00000001 of a Bitcoin (also known as a “Satoshi”), and since each fraction of a Bitcoin is interchangeable, Bitcoins can be “spent” in fractional amounts.

When a user makes a transaction, that person’s Bitcoin client broadcasts it to the rest of the network. Approximately every 10 minutes, all transactions are collected into a “block,” which is cryptographically easy to verify as correct (or not) but computationally difficult to create. Once a transaction has been contained within a block, each block that comes after it is built on top of it, which makes it exponentially more difficult to change with each additional block. A user would require 51% of the hash power to change a transaction that has been confirmed by six blocks. Because this is a continuous record, it is crucial that the entire chain of transactions is valid and follows the rules, since every transaction builds on the validity of the ones that were made previously, and each block created solidifies prior blocks.

Bitcoin Mining

Bitcoin was designed as a distributed, deflationary currency. New Bitcoins are created through a process called “mining.” Specialized chips called ASICs (application specific integrated circuits) perform Bitcoin’s SHA-256 “proof of work.” Users who have the Bitcoin client on their computers “mine” Bitcoins by running a program that solves a difficult mathematical problem in a file (the “block”), which is received by all users on the Bitcoin network. The difficulty of the problem is adjusted so that no matter how many people are mining Bitcoins at one time, the problem is solved, on average, every 10 minutes. When a miner solves the problem and causes the creation of a block, that miner is rewarded by being the first user to possess the newly issued Bitcoins. The successful miner can then sell those Bitcoins into the market to pay for his or her costs or hold them in order to speculate on their future value. The protocol for mining Bitcoins ensures that their supply is restricted. Only 21 million Bitcoins will ever be created, and the rate of creation dramatically decreases over time. For the first four years (2008–12), the rate of creation was 50 Bitcoins every 10 minutes, with the number halving about every four years. The rate of issuance in late 2013 (25 per block) is expected to be halved again in November 2016. As of 2013, more than 12 million of the total 21 million had already been created, with the limit expected to be reached in about 2140.

Since there is only one block awarded every 10 minutes to a single entity, competition is fierce, and as more people participate, individual miners join together to form “pools.” This decreases the individual reward but greatly increases the chances of finding blocks regularly. When a miner fulfills the conditions to create a block, all the transactions from the previous 10 minutes are codified into it, and the allotted number of Bitcoins are created by the protocol and sent to whatever address the successful miner specifies.

Bitcoin’s Future

As a form of money, virtual currency is a new concept. Governments around the world in 2013 began to seriously examine the technology to discern how best to regulate it, or not, and whether transactions using digital currency such as Bitcoin could be taxed. This kind of regulation is made especially difficult because Bitcoin is a protocol, not operated by any company or residing in any physical location. As a result, the users of Bitcoin can be affected by government decisions and actions, but the protocol itself cannot. In this way the borderless Bitcoin represents nonpolitical competition for government-issued hard currency in a way never before seen. This could lead to a reinvention of how social programs are funded or to attempts by government entities to ban that competition in order to better protect the value of national currencies.

It started with me crawling through the Tambopata rainforest trying to ID a lizard tucked under a mess of a tree fall. It ended with a low glance and me shouting (to myself) “Crazy-thorax membracid!”

I quickly forgot the lizard and started shooting away, fearing I would miss my chance to photograph this insect oddity that I have previously only read about and seen in photos.

The spines likely offer a bit of predator-deterrence. Credit: Phil Torres

And there she was, looking waspy and spiky. That wasp mimicry may trick something that avoids wasps, and those spines may repel anything that doesn’t like to eat spikes, but I often get stung by wasps anyway and don’t mind thorns, so I stuck around. Treehoppers (also called thorn bugs), of the plant-sucking family Membracidae, are known to have some fantastic looking species within, and most of these belong to the subfamily Stegaspidinae or Heteronotinae. This one here is Heteronotus maculatus as far as I can tell.

Also, they are not really called ‘crazy-thorax membracids,’ though I think it would make a solid common name.

Heteronotus maculatus(?) posing nicely for me. Credit: Phil Torres

The large spiky extension (called the ‘helmet’) is on the first segment of the thorax and takes on even more extreme forms in other species. In 2011, that extension was claimed to be a novel, never-before-seen-in-insects 3rd pair of wings that had gone a bit artsy. However, that hypothesis was later discredited by this paper, which shows it to merely be extensions of the tergite, rather than an articulating wing appendage.

Superficially, the spikes show a interesting developmental symmetry, making the front and back end a bit confusing for any predator, and likely very uncomfortable to eat.

You can find more information and even crazier looking members of this group here.

Cashmere goat. Credit: E.R. Degginger

Since the middle of the 18th century, cashmere has enjoyed high status as a luxurious textile in Western fashion. True cashmere is rare and expensive, as it is woven from the undercoat of mountain goats native to the Kashmir region of the western Himalayas. The delicate fibers are collected through plucking or combing, rather than sheering, to yield soft fleece that is spun into fine thread. As a woven textile, cashmere combines supple beauty with comforting warmth. In traditional Indo-Persian dress, cashmere shawls were worn by men, but in Europe, where they had become a desired import from India by the 1760s, they were worn almost exclusively by women. And by the end of the century, with the vogue for dress á la grecque, the cashmere shawl became a fashion necessity.

Circle of Jacques-Louis David, Portrait of a Young Woman in White, c. 1798, oil on canvas. Credit: National Gallery of Art, Chester Dale Collection

Inspired by the gracefully draped, clinging garments seen on ancient statuary, dress á la grecque combined a high-waisted, snug bodice with a slim, columnar skirt that followed the natural lines of a woman’s form. Made of the finest mull or silk, and cut with deeply scooped necklines and cap sleeves, these dresses revealed more than they concealed. The gown worn by Elizabeth Patterson when she wed Jêrome Bonaparte in December 1803 was described as small enough to “easily fit into a gentleman’s pocket.” Cashmere shawls provided the needed warmth, as well as a bit of seductive modesty, for a woman in her “Greek” attire. But fashions changed, and as women’s gowns grew fuller, with more ample skirts, higher necklines, and longer sleeves, the shawls lost their purpose. They also lost their prestige as a high-end import; by the 1820s, imitation “cashmere” shawls were woven for European and American customers in textile centers throughout France and Great Britain.

David Octavius Hill (Scotland, 1802-1870) and Robert Adamson (Scotland, 1821-1848)
Scotland, 1840 circa, printed circa 1910, Photogravure. Credit: Los Angeles County Museum of Art, The Marjorie and Leonard Vernon Collection, gift of The Annenberg Foundation, acquired from Carol Vernon and Robert Turbin (M.2008.40.986)

The ballooning skirts of the 1850s sparked a revival of the ample shawls. Supported by a cage understructure of baleen or steel, these dome-like skirts, paired with a tiny, fitted bodice, posed a challenge to outerwear design. How can one garment accommodate two such different silhouettes? A woman could wrap herself—and her enormous skirts—in a cashmere shawl. Large shawls, now woven in squares as well as oblongs to European specifications, enveloped the difference circumferences of a woman’s ensemble into one graceful line. In December 1850, Harper’s New Monthly Magazine cited the choice of a shawl, and a distinct “manner of wearing it,” as the clearest indications of a “gentle woman’s taste.” But the revival was brief.

John Singer Sargent, Nonchaloir (Repose), 1911, Oil on canvas. Credit: National Gallery of Art, gift of Curt H. Reisinger

By the mid-1860s, as style lines changed, so-called “cashmere” wraps were rarely worn outside the home. Increasingly fine shawls were draped over furniture or cut and sewn into a viste, a winter mantle, striking for its brilliant color as well as for its warmth.

Today, cashmere has shed its exotic origins, as well as its exclusivity, but it has not lost its cachet. There are garments at every price point. From the bespoke overcoats of Savile Row to the piles of colorful scarfs and sweaters at such fast fashion meccas as Target and H&M, everybody can wear “cashmere.” Even toddlers can enjoy the warmth and suppleness of a cashmere coat, as seen in a double-sided pink and taupe design, offered by Baby Dior. Whether groomed hair by hair from those select Himalayan goats or shorn from any one of the more than 65 breeds now used to make the soft and supple fabric, we call it cashmere. And, with winter coming on, we agree with Melissa McCarthy: “Give the girl some cashmere.”

A special thanks to Michal Raz-Russo and Kristan Hanson for suggestions for this post.

Click here to view the embedded video.

SAT and ACT scores in Texas correlate with race and income. Notice how poverty reduces the percentage of students who are ready for college. Each dot represents one high school. Courtesy The Why Files/2010 data, Michael Marder, University of Texas

Our thanks to The Why Files for permission to republish this post.

What explains the woeful underperformance of poor people in terms of showing up for appointments, taking meds on schedule or advancing in school? It’s easy to find multiple reasons: nutrition, education, family structure, environmental pollution, and the multi-tasking necessary to work several jobs so ends can meet.

Earlier this year in the journal Science, scientists reported on a new category of explanation: “cognitive load”—essentially the mental burden of thinking while dwelling on money. The study found that simply thinking about a large, unexpected expense, or facing a real, but temporary, shortage of money can slash performance on tests of concentration and problem-solving.

In the first set of experiments, shoppers in a New Jersey mall were asked how they would cope with a $150 or $1,500 car repair: Would they pay in full, borrow money, or take a chance by skipping the repair? One of the two cognitive tests, for example, measured what the authors called “the capacity to think logically and solve problems in novel situations, independent of acquired knowledge.”

Rich people—defined as having an income above the $70,000 U.S. household median—performed equally well, no matter which repair bill they had just discussed. But the cost of the repair was critical to the poor, defined as those with an income above $20,000, but below the median. The poor people who pondered the $150 bill performed just as well as the rich people, but their ability to focus and solve problems plummeted after thinking about the $1,500 expense.

Why the difference? “The people at the mall were having a good enough day to be at the mall,” says co-author Eldar Shafir, a professor of social psychology and public affairs at Princeton University. “They were not in abject poverty, were not terribly stressed. If you raise the issue of paying for the car, in one case [$150], it was relatively easy to resolve. In the other case, it gets them wondering and worrying—how are they going to go about paying for it? For the average American, to come up with $1,000 to $2,000 on short notice is not a simple thing.”

That “wondering and worrying” is key to the results, as it represents what’s called “cognitive load,” a kind of dragging brake shoe on the brain’s processing power.

Cognitive load applies when you are:

• Making an important decision while your child is wailing;

• Looking for an address and listening to a fascinating interview on the car radio; or

• Taking a final exam while obsessing about the outcome of yesterday’s job interview.

Sugar cane not so sweet

In a second group of experiments, the researchers tested Indian sugar farmers before they were paid for their harvest—when money is usually scarce—and again afterward.

In the post-harvest tests, responses came quicker, accuracy was higher, and the subjects were less distracted by irrelevant elements of the test.

But we wanted to know if this was a true test of poverty. The same farmers were tested twice, and we wondered: Could their status change from month to month?

In one sense, it can, Shafir told us. “Being poor is defined by the total amount of income in one year, and that means every month is the same.” However, the sugar farmers “have a relatively flush month after harvest, when they can buy toys for the children, eat well, go to celebrations. But if one month you are hungry and the other you have a lot to eat, [then] in one month you are poor, in the other you are not.”

Before the harvest, the need to scrimp, borrow, and go hungry were reflected in their test performance.

In the mall and the sugar field, “poor” may not be the ideal term, Shafir admits. “We are talking about people who are very concerned with budgeting, and that takes away from their cognitive bandwidth” to solve problems, he says.

We asked Shafir why cognitive load has been little used in the study of poverty. “If you work in cognitive science, you are studying the way mental life happens, the way the brain functions, and you don’t care if you are studying Koreans, Chinese, or Americans, or the poor or the rich,” he says.

Studies of poverty have been the realm of economics, Shafir adds. “Before, the economists did their work and did not rely on cognitive psychology, and the cognitive psychologists did their work, and did not rely on economics.”

Practical matters

Timothy Smeeding, director of the Institute for Research on Poverty at the University of Wisconsin-Madison, says the research is “very important,” especially in explaining why poverty is often passed from one generation to the next.

There are other explanations for poor mental functioning among the poor, such as higher rates of disease, poor nutrition, and environmental pollution, so the new results are not a comprehensive explanation, Smeeding says. The cause of bad decisions “could well be overloaded circuits, but it may also be because of health status, genetics…or even because of having a poor education,” he says.

In practical terms, Smeeding notes, the study “pushes the boundaries of science in ways that we may be able to alleviate through policy.” Emergency savings programs or faster access to income support could “allow the poor some cushion or help reduce the cognitive load, enabling better decisions in various realms,” he says.

Indeed, the Science authors suggest that simplifying government forms or providing child care for people as they deal with bureaucracies could improve decision-making by reducing cognitive load.

– David Tenenbaum

Terry Devitt, editor; S.V. Medaris, designer/illustrator; Yilang Peng, project assistant; David J. Tenenbaum, feature writer; Amy Toburen, content development executive

Related Why Files
The psychological price of job loss
Science of spending
Poverty: Changing the body, changing the brain
In detail: How learning changes brain
Internet: The fastest teacher?
Investments: The psychology of money

Bibliography
1. “Poverty Impedes Cognitive Function,” Anandi Mani et al, Science, 29 August 2013. ↩
2. Poverty goes straight to the brain ↩
3. The psychology of poverty ↩
4. Brains of poor children ↩
5. Poverty as a childhood disease ↩

Scanning electron micrograph of HIV-1 virions (green) budding from a cultured lymphocyte. Multiple round bumps on the cell surface represent sites of virion assembly and budding. Credit: C. Goldsmith/Centers for Disease Control and Prevention (CDC)

Since 1938 Britannica’s annual Book of the Year has offered in-depth coverage of the events of the previous year. While the 75th anniversary edition of the book won’t appear in print for several months, some of its outstanding content is already available online. This week, in honor of World AIDS Day, the Britannica Blog features this article by Britannica editor Kara Rogers on the possibility of a cure for HIV.

Is There a Cure for HIV?

In 2013 the world learned that a two-year-old child and two adults had been cured of HIV, the virus that causes AIDS. The news seemed to hail the beginning of HIV’s end, but within the medical community, there was doubt and confusion over the implications. Was there something unique about the Mississippi child, as he or she came to be known, or could other children be cured too? The two adults, known as the Boston patients, suffering from lymphoma, underwent potentially life-threatening allogeneic (nonself) hematopoietic stem-cell transplantation (HSCT)—a procedure that entails the exchange of a patient’s blood-forming cells for those from a donor. Many viewed HSCT as impractical and too risky for the vast majority of HIV victims.

At the same time, however, some thought that the child’s success story warranted a review of the standard of care for HIV-infected infants and that HSCT was of value for other HIV-infected patients with cancers of blood-forming tissues. Furthermore, despite the uncertainties, researchers agreed that the three cases marked significant milestones in HIV research, particularly for the insight that they offered into ways to weaken or eliminate the HIV reservoir—the store of latent virus in the body that was notorious for escaping drug therapy and that represented the greatest obstacle in the path to an HIV cure.

The Mississippi Child

News of the Mississippi child’s cure reached the public in March, following an announcement at a conference in Atlanta by virologist Deborah Persaud of the Johns Hopkins Children’s Center, Baltimore, Md. Persaud had been working with University of Massachusetts immunologist Katherine Luzuriaga to gather information about possible cures for pediatric HIV infection. They learned of the child when University of Mississippi Medical Center pediatric infectious disease specialist Hannah B. Gay contacted Luzuriaga, expressing amazement that the child was free of the virus despite a monthslong hiatus in antiretroviral therapy.

The child had been born prematurely in a Mississippi hospital, where the mother, who had not received antiretroviral therapy or prenatal care, underwent testing during labour that confirmed that she was HIV-positive. Her doctors immediately transferred the baby to the University of Mississippi Medical Center, where Gay ordered blood tests that revealed HIV infection. Though the infant was just 30 hours old, Gay started the baby on a three-drug antiretroviral regimen aimed at treating the infection. Normal protocol in such a case would have been to use a prophylactic regimen of one or two drugs. Within days the infant’s viral load dropped, and within one month the virus had become undetectable.

The child continued antiretroviral therapy until the age of 18 months, when the family unexpectedly stopped their hospital visits. When they returned months later and Gay could find no evidence of HIV in the child, extensive testing was undertaken. The tests revealed only traces of the virus’s genetic material, with no evidence of the virus itself in either the blood or the reservoirs in the body where it normally lies dormant. Gay’s bold treatment regimen was projected by some to become the standard of care for HIV-infected infants.

The Boston Patients

In early July doctors announced at a conference in Kuala Lumpur, Malay., that two HIV-positive men who had been treated with HSCT for lymphoma—one in 2008 and the other in 2011—were continuing to live HIV-free. The patients, treated at Brigham and Women’s Hospital, Boston, had initially continued antiretroviral therapy following their transplants. In 2013, however, they discontinued therapy, and at the time of the announcement, neither patient had detectable levels of HIV RNA or DNA in the blood. As in the Mississippi child case, however, some researchers were concerned that the virus might have been lying hidden in an inaccessible tissue reservoir, such as the brain. For that reason, all three patients were considered to have been functionally cured, with the immune system having suppressed and maintained the virus below measurable levels.

Earlier Documented Cases of HIV Clearance

The Mississippi child was not the first HIV-infected child to have later been declared free of the virus. In 1995 researchers reported in The New England Journal of Medicine that an infant who had tested positive for HIV at 19 days and again at 51 days of age was HIV-negative at 12 months. The infant had not received any treatment, and the child had been HIV-free for five years when the report was published. Subsequent letters to the editor, however, called into question the method of HIV diagnosis used and noted that in infants with an often fatal form of inherited immune deficiency (severe combined immunodeficiency), maternal T cells sometimes persisted in the infant’s circulation, possibly for as long as one year. Since T cells harbour HIV, there was suspicion that what had been detected in the infant was a subset of maternal HIV-infected T cells.

HIV clearance also had been documented previously in adults, beginning in 1989 with an HIV-positive patient who had undergone allogeneic HSCT for lymphoma. The patient was HIV-negative following transplantation but died shortly after from tumour relapse. The most-popularized case involved a 42-year-old man who had been cured of both leukemia and HIV, as described in 2009 in The New England Journal of Medicine. The man, who came to be known as the Berlin patient (because he was treated at the Charité hospital in that city), had been cleared of HIV following stem-cell transplantation for acute myeloid leukemia and was no longer on antiretroviral therapy. His doctors purposely selected a donor whose cells carried an HIV-resistant mutation in a gene known as CCR5. The Berlin patient was living without HIV in 2013.

The Role of the HIV Reservoir

It has been well documented that HIV reservoirs establish themselves early in the infection process. The largest and most insidious of those is a latent reservoir in a subset of immune cells known as resting memory CD4(+) T cells. Those cells carry integrated HIV DNA, which can replicate to produce new virus particles but typically is not active until antiretroviral therapy has been stopped. The latent reservoir enabled lifelong persistence of HIV and was inaccessible to antiretroviral drugs, which were able to attack only actively replicating virus.

Though adults have populations of memory T cells, infants do not. Rather, they develop T-cell memory with exposure to antigens (proteins that provoke an immune response). Researchers suspected that this difference was of special importance to HIV infection in the infant. They hypothesized that if aggressive antiretroviral therapy was initiated in an HIV-positive infant within hours of birth, it would be possible to prevent the establishment of an HIV reservoir. That may have happened in the Mississippi child. Such a strategy, to be successful, would require intense drug therapy early on, but that therapy eventually could be terminated, possibly eliminating the need for lifelong treatment from infancy.

Researchers were hopeful that the Berlin and Boston patient cases would shed light on a possible means by which the HIV reservoir could be eliminated in adults. Finding ways to minimize or attack the latent reservoir, without the need for high-risk procedures such as HSCT, was a central objective of this effort. By 2013 there had emerged one potential lead—the VISCONTI study, an investigation of HIV-positive patients conducted in France that explored the use of early antiretroviral intervention to produce a functional cure. In March the study’s leaders reported that 14 VISCONTI patients who had begun therapy within 10 weeks of becoming infected and then had their therapy discontinued several years later were able to control their viral infections without medication. The patients were described as elite controllers, and the researchers estimated that some 15% of HIV-infected individuals could become elite controllers if treated early. Some researchers thought that the Mississippi child might have provided an example of one of those individuals.

* * *

This Black Friday, amid the flurry of deals and doorbusters, midnight openings and madhouses, we have a lesson in how to spend money wisely: 1978′s “Choosing What to Buy.” In this classic film, a puppet discovers a quarter and must decide—through song and dance, of course—how to spend his windfall.

Click here to view the embedded video.

What makes this a clear product of its time is the amount of money used. I fear that many students in today’s audience would barely blink over a dollar, much less a fraction of that amount. But the quarter is a great and wondrous prize to our puppet friend. He encounters a variety of possible purchases as he bounces down the (seemingly Sesame) street. Does he want a toad? Ice cream? Candy? Toys? Groucho Marx glasses?

In the end, he finally selects his prize: rope. Oh, the crazy excesses of the 1970s.

But the thing that really sells this video for me is the closing number. A folk song about capitalism—what a wonderful gift for us all as we begin this holiday season.