Maya’s notebook (Written by Isabel Allende)
The Stones of Venice (John Rushkin)
Moths remember what they learn as caterpillars
Accordingto popular belief, within the pupa, the caterpillar’s body is completely overhauled,broken down into a form of soup and rebuilt into a winged adult.
RichardBuckmister Fuller once said that “there is nothing in a caterpillar that tellsyou it’s going to be a butterfly.” Indeed, as the butterfly or moth quiteliterally flies off into a new world, it is tempting to think that there is noconnection between its new life and its old existence as an eatingmachine.
But not so. A new study has provided strong evidence that the larval and adult stages are not as disparate as they might seem. Adult tobacco hookworms –a species of moth – can remember things that it learned as a caterpillar, which means that despite the dramatic nature of metamorphosis, some elements of the young insect’s nervous system remain intact through the process.
Using some mild electric shocks, Douglas Blackiston from Georgetown University trained hookworm caterpillars (Manduca sexta) to avoid the scent of a simple organic chemical –ethyl acetate. The larvae were then placed in the bottom end of a Y-shaped tube, with the scent of ethyl acetate wafting down one arm and fresh air coming down the other. Sure enough, 78% of the trained caterpillars inched down theodour-free arm.
Asthe caterpillar moulted their way through the larval stage, their aversion toethyl acetate remained. Blackiston allowed them to pupate and emerge asfull-grown moths, before testing them again, about a month after their initial‘electric’ education. Bear in mind that a tobacco hornworm lives for about 30to 50 days, so a month is very close to its entire lifespan.
Amazingly,77% of the adult moths also avoided the ethyl acetate-scented arm of theY-shaped tube and the vast majority of these were the adult versions of thesame larvae that had correctly learned the behaviour originally. Clearly, thelarvae had learned to avoid the chemical and that memory carried over intoadulthood.
Evenso, Blackiston was careful to rule out alternative explanations. For a start,ethyl acetate isn’t naturally foul-smelling. It’s actually rather reminiscentof pear drops and when larvae are exposed to it in the absence of electricshocks, neither they nor the adults they become learn to avoid it.
Anotherpossible explanation hinges on the fact that adults emerging from the pupausually experience a similar milieu of smells to their caterpillar selves.
Thischemical legacy’ could explain why adults and larvae react similarly to someodours. But when Blackiston applied ethyl acetate gel to the pupae of untrainedcaterpillars, the adults did not shrink away from the chemical. Nor did washingthe pupae of trained caterpillars, to get rid of any lingering traces of ethylacetate, have any effect.
Blackistonwas convinced that some aspect of the caterpillar’ nervous system was carriedover into adulthood. However, he also found that this only happened ifcaterpillars are trained at the last possible stage before they pupate – the‘fifth instar’. Any earlier, and the memories don’t stick.
Thefruitfly Drosophila suggestswhy this might happen. In its brain, memories of smells are located in mushroombodies, brain structures that consist of three lobes. The gamma lobe developsvery early while the alpha and beta lobes develop just before the pupal stage.
Blackistonthinks that long-lasting larval memories are writ into the alpha and betalobes, whose neural networks are kept around while the rest of the caterpillarbreaks down. If the larvae are too young, these areas haven’t developed yet andany learned information is stored in the gamma lobe and lost when itsconnections are trimmed back in the pupa.
But why bother? After all, the entire advantage of metamorphosis rests on the very different lifestyles and habitats of caterpillars and moths, which allow them to avoid competing with each other. Nonetheless, moths and butterflies must still return to the right sort of plant in order to lay their eggs and Blackiston suggests that their larva-hood memories may help them to do so.
the effects of color images on consumers
That’s the conclusion of astudy at The Ohio State University, which found that people who were shownproduct images in color were more likely to focus on small product details—evensuperfluous ones—instead of practical concerns such as cost andfunctionality.
The findings, published in the Journal of Consumer Research, mesh well with notions of how vision evolved inthe brain, and suggest that viewing objects in black and white helps our brainsfocus on what’s most important.
“Color images help us noticedetails,” said Xiaoyan Deng, an author of the study andassistant professor of marketing at Ohio State. “Butblack-and-white images let us see the ‘big picture’ without getting bogged downby those details.”
The findings also suggest howmarketers can strategically use color—or its absence—to change how we feelabout a product.
“Marketers may take it forgranted that color is always the best presentation format for advertising,”Deng added. “This study shows that while color is desirable in most situations,it’s not desirable in all situations.”
If a product has broad featuresthat set it apart from the competition, then black-and-white images will helpcustomers cast aside minor details and focus on those key features, theresearchers found. If a product’s details are what set it apart, color imageswill make those details stand out.
In one part of the study, 94college students were asked to imagine that they were traveling to a remotecampsite where they could receive only one radio station. There, the campsitemanager offered two radios for rent: a basic analog radio for $10 a day, or afancy digital radio with many station preset buttons for $18 a day. Not onlywas the digital radio more expensive, but its preset buttons would be uselessat the campsite.
Students who saw pictures ofthe radios in black and white tended to make the practical choice—the analogradio. Only 25 percent chose the digital radio.
But among students who saw theradios in color, twice as many chose the digital radio. In that scenario, 50percent of students were willing to pay a higher price for a radio withfeatures that they could not use.
“Color drew their focus awayfrom the most important features to the less important features, and theirchoice shifted to the more expensive radio,” Deng said. “I think that’ssurprising—that just by manipulating whether the product presentation is incolor or black and white, we can affect people’s choice.”
Color also proved to be adistraction when study participants were asked to sort objects into groups. Theresearchers recruited people through Amazon Mechanical Turk, a service thatprovides online study participants.
The 287 participants were shownpictures of shoes and asked to sort them. Each grouping contained two types ofshoes that differed greatly in form and function, such as open-toe high heelsand rain boots. In that particular example, half of the high heels and theboots were a solid red color, and the other half were red with white polkadots.
When people viewed the shoes inblack and white, they sorted the high heels into one group and the rain bootsinto another 97 percent of the time. But when they saw the shoes in color, thatnumber dropped to 89 percent, with 11 percent sorting the solid-color highheels and boots into one group and the polka-dot heels and boots into another.
The polka dots were clearlyvisible in black and white, but they had more impact on participants’decision-making when they were seen in color.
Study co-author Kentaro Fujita, associate professor of psychology at Ohio State, has an idea why. It has to dowith the origin of our visual systems, and how our brains process night vision.
Of the light-sensitive rod and cone structures in the retina, it’s the cones that detectcolor and the rods that give us night vision, peripheral vision and motiondetection. Rods outnumber cones in the eye 20 to 1, and at night, when thecones don’t receive enough light to let us distinguish colors properly, we relyon the rods to see what’s happening around us—in black and white.
This would have been especiallytrue for early humans, who didn’t have sources of artificial light. At night,being able to tell the difference between objects by shape would have been keyto survival.
“Our visual systems evolved towork in both optimal and suboptimal conditions,” Fujita explained. “Optimalconditions might be during the day, when I want to distinguish a red apple froma not-so-red apple. The form of the object tells me it’s an apple, but I canfocus on the color because that’s what’s important to me. Suboptimal conditionsmight be at night, when I have to tell whether that object that’s moving towardme is my friend or a hungry lion. Then the form of the object is critical.”
He suspects that when our eyessee black-and-white images, our brains interpret them in ways similar to nightvision: We focus on form and function, and tend to ignore details.
Whether plants have Neuro System
“Yes, plants have both short- and long-term electrical signalling, and they use some neurotransmitter-like chemicals as chemical signals,” Lincoln Taiz, an emeritus professor of plant physiology at U.C. Santa Cruz and one of the signers of the Alpi letter, told me. “But the mechanisms are quite different from those of true nervous systems.” Taiz says that the writings of the plant neurobiologists suffer from “over-interpretation of data,teleology, anthropomorphizing, philosophizing, and wild speculations.” He is confident that eventually the plant behaviors we can’t yet account for will be explained by the action of chemical or electrical pathways, without recourse to“animism.” Clifford Slayman, a professor of cellular and molecular physiologyat Yale, who also signed the Alpi letter (and who helped discredit Tompkins and Bird), was even more blunt. ” ‘Plant intelligence’ is a foolish distraction, not a new paradigm,” he wrote in a recent e-mail. Slayman has referred to the Alpi letter as “the last serious confrontation between the scientific community and the nuthouse on these issues.” Scientists seldom use such language when talking about their colleagues to a journalist, but this issue generates strong feelings, perhaps because it smudges the sharp line separating the animal kingdom from the plant kingdom. The controversy is less about the remarkable discoveries of recent plant science than about how to interpret and name them: whether behaviors observed in plants which look very much like learning, memory, decision-making, and intelligence deserve to becalled by those terms or whether those words should be reserved exclusively for creatures with brains.
讲一个校长如何加强民众对于African American history的意识，说要在学校举办 African American history week， 然后一开始好多人反对，也没人支持，后来有个组织支持慢慢搞成了这个week，最后大概就是说通过了这个活动提高了民众对于African American history 的意识吧。
说一个画家画得特别精准， 非常真实，像是照片一样，通过一个设备叫做camera obscura画出来，一个科学家为了验证这个人画的画是否用了这个仪器，虽然有些人不同意，但最后其实是证实了这个画家用了这个仪器。