雅思阅读 强化段

A  In the past, urban home owners have not always had much choice in the way electricity is supplied to their homes. Now, however, there is a choice, and a rapidly increasing number of households worldwide are choosing the solar energy option. Solar energy, the conversion of sunlight into energy, is made possible through the use of photovoltaics, which are simple appliances that fit onto the roof of a house.

B  The photovoltaics-powered home remains connected to the power lines, but no storage is required on-site, only a box of electronics (the inverter) to the interface between the photovoltaics and the grid network. Figure 1 illustrates the system. During the day, when the home may not be using much electricity, excess power from the solar array is fed back to the grid, to factories and offices that need daytime power. At night, power flows the opposite way. The grid network effectively provides storage. If the demand for electricity is well matched to when the sun shines, solar energy is especially valuable. This occurs in places like California in the US and Japan, where air-conditioning loads for offices and factories are large but heating loads for homes are small.

C  The first systematic exploration of the use of photovoltaics on homes began in the US during the 1970s. A well-conceived program started with the sitting of a number of residential experiment stations' at selected locations around the country, representing different climatic zones. These stations contained a number of 'dummy' houses, each with a different solar-energy system design. Homes within the communities close to these stations were monitored to see how well their energy use matched the energy generated by the stations' dummy roofs. A change in US government priorities in the early 1980s halted this program.

D  With the US effort dropping away, the Japanese Sunshine Project came to the fore. A large residential test station was installed on Rokko Island beginning in 1986. This installation consists of 18 'dummy' homes. Each equipped with its own 2-5 kilowatt photovoltaic system (about 20 – 50 square meters for each system). Some of these simulated homes have their own electrical appliances inside, such as TV sets, refrigerators and air conditioning units, which switch on and off under computer control providing a lavish lifestyle for the non-existent occupants. For the other systems, electronics simulate these household loads. This test station has allowed the technical issues involved in using photovoltaics within the electricity network to be explored in a systematic way, under well-controlled test conditions. With no insurmountable problems identified, the Japanese have used the experience gained from this station to begin their own massive residential photovoltaics campaign.

E  Meanwhile, Germany began a very important '1,000 roof program' in 1990, aimed at installing photovoltaics on the roofs of 1,000 private homes. Large federal and regional government subsidies were involved, accounting in most cases for 70% of the total system costs. The program proved immensely popular, forcing its extension to over 2,000 homes scattered across Germany. The success of this program stimulated other European countries to launch similar programs.

F  Japan's 'one million roof program' was prompted by the experience gained from the Rokko Island test site and the success of the German 1000 roof program. The initially quoted aims of the Japanese New Energy Development Organization were to have 70000 homes equipped with the photovoltaics by the year 2000, on the way to 1 million by 2010. They made a modest start in 1994, when 539 systems were installed with a government subsidy of 50 percent. Under this program, entire new suburban developments are using photovoltaics.

G  The Japanese initiative in embracing residential photovoltaics on a large scale prompted responses in both Europe and the US. The European Commission has called for one million solar residential systems before the year 2010, with 500,000 in Europe and 500,000 in the developing world, to be subsidised by the Commission. In 1997, a similar one million roof target was announced in the US. Since then, several other countries including Germany, Italy, the Netherlands and Australia, have announced their own targets for residential photovoltaics.

H  This is good news, not only for the photovoltaic industry but for everyone concerned with the environment. The use of fossil fuels to generate electricity is not only costly in financial terms, but also in terms of environmental damage. Gases produced by the burning of fossil fuels in the production of electricity are a major contributor to the greenhouse effect. To deal with this problem, many governments are now proposing stringent targets on the amount of greenhouse gas emissions permitted. These targets mean that all sources of greenhouse gas emissions including residential electricity use will receive closer attention in the future.

I  It is likely that in the future, governments will develop building codes that attempt to constrain the energy demands of new housing. For example, the use of photovoltaics or the equivalent may be stipulated to lessen demands on the grid network and hence reduce fossil fuel emissions. Approvals for building renovations may also be conditional upon taking such energy-saving measures. If this were to happen, everyone would benefit. Although there is an initial cost in attaching the system to the rooftop, the householder's outlay is soon compensated with the savings on energy bills. In addition, everyone living on the planet stands to gain from the more benign environmental impact.

Figure 1

A  A tiny insect navigates its way across featureless salt-pans. A cockroach successfully works out how to scramble over an obstacle. The mantis shrimp scans its aquatic world through hyperspectral eyes. Using the most basic of equipment and brains tinier than a pin-head, insects constantly solve complex problems of movement, vision and navigation — processing data that would challenge a super-computer. How they do it is driving one of the most exciting new fields of technology — biomimetics and biorobotics, the imitation of insect systems to control man-made machines. Delegates at a recent conference presented some outcomes of their work in this area.

B  Dr Alex Zelinsky suggested that the method by which wasps use landmarks to find their way back to the nest may one day be part of a system for navigating cars that know where to go. A research team led by Dr Zelinsky has shown that a robot can navigate its way among 50 different landmarks by recognising them individually using a panoramic camera. "The inspiration came from biology, where wasps use a practical method turn back and look to orient themselves as they emerge from their nest. By flying to and fro, they look at the wasp nest from different angles and perspectives so they can recognise it again," he explained. The robot's panoramic camera logs the surrounding area and its key landmarks, which are then stored in its computer according to how reliable they are as navigational aids. The landmarks are then scaled, from small to large, so that the robot can recognise whether it is getting closer to or further away from them. Their location is built into a map in its mind, which operates at different scales and instructs the robot whether to turn left or right at a particular mark. The technology provides a general way for a machine to navigate an unknown landscape.

C  For three decades, Professor Ruediger Wehner has journeyed from Switzerland to the Sahara Desert where Cataglyphis, a tiny ant with a brain weighing just 0.1 mg, performs acts of navigational genius when it leaves its nest, forages for food and returns successfully. Cataglyphis uses polarised light, caused when air molecules scatter light, to orient and steer itself. Wehner's team found that the ant has a set of specialised photoreceptors along the upper rim of its eyes that detect polarised light, while other receptors perform different navigational tasks. As the sun moves, the ant notes its direction each time it leaves the nest and updates its internal compass. Using other eye receptors it stores a snapshot image of landmarks close to the nest entrance in its eyes and compares this with what it sees as it returns. The ant also has a way of measuring distance travelled, while a path integrator periodically informs the ant of its current position relative to its point of departure. Rather than integrate all the information it receives in its brain, the ant actually performs a number of complex calculations in different organs. Like a super-computer, the ant has many separate sub-routines going on simultaneously. Using the ant's ability to steer by polarised light and to store and reuse landscape images, Wehner and colleagues have built "Sahabot," a small vehicle that uses polarisers and a CCD camera to store 360° images of its surroundings. It navigates by using polarised sunlight and comparing the current images of landmarks to the ones in its memory.

D  Professor Robert Michelson had a different desert challenge — to design a flying robot that can not only navigate but also stay aloft and hover in the thin atmosphere of Mars. Drawing inspiration from insect flight, he has gone beyond nature to devise a completely new concept for a flying machine. The "Entomopter" is a sort of double-ended dragonfly whose wings beat reciprocally. Michelson says that the flapping-wing design gives the craft unusually high lift compared with a fixed-wing flyer, enabling it to fly slowly or hover in the thin Martian air — whereas a fixed-wing craft would have to move at more than 400 km/h and could not stop to explore.

E  Engineer Roger Quinn and entomologist Professor Roy Ritzmann are taking their inspiration from cockroaches. According to Quinn and Ritzmann, the ability of cockroaches to run very fast over rough terrain may one day give rise to a completely new all-terrain vehicle with six legs, or maybe even wheel-like legs called "whegs." The key to the cockroach's remarkable cross-country performance lies partly in the fact that its legs do a lot of the thinking without having to consult the brain. Quinn and Ritzmann are drawing on cockroach skills to create robotic walkers and control strategies that capture the remarkable capacity of these insects to traverse complex terrain and navigate safely toward goals while avoiding obstacles. The team has already designed a series of robots that run on six legs or on whegs, enabling them to handle surprisingly rugged terrain.

F  International experts believe there are tremendous opportunities in biorobotics. However, delegates at the conference had differing visions for the future of the science. While some were concerned that the initial applications of biorobotics may be military, others, such as Dr Barbara Webb, predicted swarms of tiny, cheap, insect-like robots as society's cleaners and collectors. Sonja Kleinlogel hoped the study of the hyperspectral eyes of the mantis shrimp might yield remote sensors that can watch over the environmental health of our oceans. Several delegates were concerned about the ethical implications of biorobotics and urged that close attention be paid to this as the science and technologies develop.

A  Nanoscience and nanotechnology have become very fashionable in recent times. Their prominence has inspired science fiction and raised a lot of hope and hype about the possibilities. But what exactly is nanotechnology? Most definitions agree that it is the manufacture of structures that measure up to 100 nanometres (nm). The diameter of an atom is typically only two or three tenths of a nanometre while that of the human hair is around 1,000,000 nm. Essentially, we are now able to build new structures from atoms and molecules as if we were using the bricks of a children's construction toy.

B  Most of the electronic consumer goods that we use today contain components that measure less than 100 nm. The lasers in our CD and DVD players make use of the properties of semiconductor layers that are just a few atoms in thickness, so we clearly are in the nanotechnology age. There are many other everyday items that we take for granted that have nanoparticles in them. One of these is sunscreen. In the 1990s there were safety issues with many of the sunscreen products available, so scientists at Oxford University set about finding a solution. The product they developed uses nanoparticles of titanium dioxide that are doped with the element manganese. This product is almost transparent to the eye when spread on the skin, and it is effective for much longer than many of the traditional preparations. In this case, we see an example of nanotechnology providing a solution to an existing problem rather than opening up new product areas.

C  The technique of using nanotechnology to adapt existing products can also be applied to garments, upholstery, paint, and plastics to improve their longevity. Bearing this in mind, it is interesting to ask whether nanotechnology can help with some of the world's major current issues. The recent growth in climate change awareness calls a range of things into question. Can we use energy more effectively? Can we reduce the carbon dioxide in the atmosphere? Can we use and purify water more effectively? Can health care be improved? Nanotechnology may very well provide the solutions. There are few times in history when the application of science to improving the human condition has been so apparent.

D  We are already making new types of solar cells and batteries by using our newfound ability to manipulate matter at the atomic and molecular scale. If we can capture some of the huge quantities of energy that arrive at the Earth's surface from the Sun, and store it effectively, we can reduce the need for fossil fuel-based power stations. We are already using nanoparticles and nanoporous materials to capture harmful greenhouse gases, and we may possibly convert some of them back into fuel. There are, however, many technical problems involved, and it will be another decade or so before some of these ideas are deployed.

E  Water purification is increasingly challenging and many believe that water, which we take for granted, is going to become more valuable than oil. Currently we do not use water efficiently, and many industrial and food processes leave contamination in water that is potentially toxic and difficult to remove. Nanofiltration may provide the solution to these problems, and may also offer new routes to the desalination of brackish water and groundwater in some parts of the world.

F  Food production and processing are becoming more important as the world's population increases. There are concerns that potentially harmful nano-products might enter the body via the gut. Such concerns are being addressed, but it is even more important to ask questions about how nanotechnology might increase the nutritious yield of food and be adapted to help preserve and package food. There is already evidence to show that it might also be helpful in the primary production of raw food materials, by way of better delivery of pesticides in the field and better extraction of protein and carbohydrates.

G  Healthcare is an area where the application of nanotechnology is already exceeding the expectations of ten years ago. It is happening across several fronts: better appreciation of what the 'natural' nanoparticles circulating in body fluid do; better methods of delivering drugs to the body via nanoparticles that target the diseased body part; improvements to the diagnostic imaging techniques of ultrasound, magnetic resonance imaging and X-ray computerised tomography. We are now at the threshold of a new subject, 'theranostics', whereby nanoparticles will first deliver the diagnostic information to the clinician and then, using the same particle, deliver a form of therapy.

H  Nanotechnology is a life-changing technology, making the quality of life better, enabling us to make use of our resources more effectively, thereby protecting our environment, and creating new business opportunities. There are many other examples in the world of 'new materials' that also make use of nanotechnology. The possibilities may well be limitless.

A  Famous for their taste, color, and organic appearance, heirloom tomatoes are favorites of gardeners and advocates of locally grown foods. The tomato enthusiast might conclude that, given the immense varieties, heirlooms must have a more diverse and superior set of genes than the tomatoes available in grocery stores, those ordinary hybrid varieties such as cherry and plum. However, their seeming diversity is only skin-deep: heirlooms are actually feeble and inbred — the defective product of breeding experiments that began hundreds of years ago, and exploded thanks to enthusiastic backyard gardeners. "The irony of all this," says Steven Tanksley, a geneticist at Cornell University, "is that all that diversity of heirlooms can be accounted for by a handful of genes. There are probably no more than 10 mutant genes that create the diversity of heirlooms you see." But rather than simply proving that the myth about the heirlooms' diversity is wrong, Tanksley's deconstruction of the tomato genome, along with work by others, is showing how a small berry-like fruit from the Andes became one of the world's top crops.

B  The cultivated tomato is a member of the nightshade family that includes New World crops such as the potato, which spread around the globe after Christopher Columbus brought them back to Spain in the 15th century. But whereas scientists have uncovered a wealth of archaeological evidence on early farming practices in the New World, the record is blank when it comes to the tomato. The modern tomato seems to have its origins in the Andes in South America and may have been domesticated in Veracruz, Mexico. Primitive varieties still grow throughout the Americas. All told, botanists call as many as 13 species "tomatoes" and consider an additional four to be closely related.

C  One might assume that one of these known wild species became today's cultivated crop, but that's not the case: the Mother Tomato has never been found. The closest relative is the currant tomato, which, based on genetic comparisons, split from today's tomato some 1.4 million years ago. So researchers like Tanksley have to work backward, crossing tomato varieties and species in order to understand how various genes influence shape and size. Once isolated, Tanksley later inserts those genes into other tomato varieties to make his case with a dramatic transformation.

D  Tanksley concludes from his analyses that in their effort to make bigger, tastier, and faster-growing fruit, our ancestors ultimately exploited just 30 mutations out of the tomato's 35,000 genes. Most of these genes have only small effects on tomato size and shape, but recently Tanksley and his colleagues reported that they found a gene that increases fruit size by 50 percent. It was probably the most important event in domestication. The first written record of tomatoes — from Spain in the 1500s — confirms that this mutation, which enlarges tomatoes by producing compartments known as locules, existed back in the same yellow tomatoes that gave Italians the word pomodoro, or golden apple. Besides size, tomato farmers also selected for shape. To discover those genes, Esther van der Knaap, a Tanksley alumna now at The Ohio State University, took a gene from one heirloom tomato and inserted it into a wild relative. She observed that, as a result, the tiny fruits became shaped like pears.

E  The selection of these traits has, however, affected the heirlooms' hardiness. They often suffer from infections that cause the fruit to crack, split, and otherwise rot quickly. Wild plants must continuously evolve to fend off such infections, points out Roger Chetelat of the Tomato Genetics Resource Center at the University of California. But in their quest for size, shape, and flavor, humans have inadvertently eliminated defensive genes. As a result, most possess only a single disease-resistant gene. Chetelat elaborates that heirlooms' taste may have less to do with their genes than with the productivity of the plant and the growing environment. Any plant that produces only two fruits, as heirlooms sometimes do, is highly likely to produce juicier, sweeter, and more flavorful fruit than varieties that produce 100, as commercial types do. In addition, heirlooms are sold ripened on the vine, a certain way to get tastier results than allowing them to mature on the shelf. This means breeders feel confident that getting germ-beating genes back into heirlooms won't harm the desirable aspects of the fruit. Modern breeding has resuscitated grocery-store tomatoes with an influx of wild genes; in the past 50 years, as many as 40 disease-resistant genes have been bred back into commercial crops.

F  In 1996, a tomato breeder and former Tanksley student named Doug Heath began a favorite project. After 12 years of traditional breeding with the help of molecular markers, he created a new multi-colored tomato less prone to cracking and also endowed with 12 disease-resistant genes. The original heirloom plant, Heath explains, had defective flowers, which is one reason why it produced only two fruits compared with the 30 he gets from his new variety. He claims he is also able to maintain a comparable flavor and sugar profile even on productive plants. The heirloom's defects are, after all, just an accident of a narrow breeding strategy left over from the very beginning of genetic modification.

One of the first great intellectual feats of a young child is learning how to talk, closely followed by learning how to count. From earliest childhood we are so bound up with our system of numeration that it is a feat of imagination to consider the problems faced by early humans who had not yet developed this facility. Careful consideration of our system of numeration leads to the conviction that, rather than being a facility that comes naturally to a person, it is one of the great and remarkable achievements of the human race.

It is impossible to learn the sequence of events that led to our developing the concept of number. Even the earliest of tribes had a system of numeration that, if not advanced, was sufficient for the tasks that they had to perform. Our ancestors had little use for actual numbers; instead their considerations would have been more of the kind 'Is this enough?' rather than 'How many?' when they were engaged in food gathering, for example.

However, when early humans first began to reflect on the nature of things around them, they discovered that they needed an idea of number simply to keep their thoughts in order. As they began to settle, grow plants and herd animals, the need for a sophisticated number system became paramount. It will never be known how and when this numeration ability developed, but it is certain that numeration was well developed by the time humans had formed even semi-permanent settlements.

Evidence of early stages of arithmetic and numeration can be readily found. The indigenous peoples of Tasmania were only able to count one, two, many; those of South Africa counted one, two, two and one, two twos, two twos and one, and so on. But in real situations the number words are often accompanied by gestures to help resolve any confusion. For example, when using the one, two, many type of system, the word many would mean, 'Look at my hands and see how many fingers I am showing you.' This basic approach is limited in the range of numbers that it can express, but this range will generally suffice when dealing with the simpler aspects of human existence.

The lack of ability of some cultures to deal with large numbers is not really surprising. European languages, when traced back to their earlier version, are very poor in number words and expressions. The ancient Gothic word for ten, tachund, is used to express the number 100 as tachund tachund. By the seventh century, the word teon had become interchangeable with the tachund or hund of the Anglo-Saxon language, and so 100 was denoted as hund teontig, or ten times ten. The average person in the seventh century in Europe was not as familiar with numbers as we are today. In fact, to qualify as a witness in a court of law a man had to be able to count to nine!

Perhaps the most fundamental step in developing a sense of number is not the ability to count, but rather to see that a number is really an abstract idea instead of a simple attachment to a group of particular objects. It must have been within the grasp of the earliest humans to conceive that four birds are distinct from two birds; however, it is not an elementary step to associate the number 4, as connected with four birds, to the number 4, as connected with four rocks. Associating a number as one of the qualities of a specific object is a great hindrance to the development of a true number sense. When the number 4 can be registered in the mind as a specific word, independent of the object being referenced, the individual is ready to take the first step toward the development of a notational system for numbers and, from there, to arithmetic.

Traces of the very first stages in the development of numeration can be seen in several living languages today. The numeration system of the Tsimshian language in British Columbia contains seven distinct sets of words for numbers according to the class of the item being counted: for counting flat objects and animals, for round objects and time, for people, for long objects and trees, for canoes, for measures, and for counting when no particular object is being numerated. It seems that the last is a later development while the first six groups show the relics of an older system. This diversity of number names can also be found in some widely used languages such as Japanese.

Intermixed with the development of a number sense is the development of an ability to count. Counting is not directly related to the formation of a number concept because it is possible to count by matching the items being counted against a group of pebbles, grains of corn, or the counter's fingers. These aids would have been indispensable to very early people who would have found the process impossible without some form of mechanical aid. Such aids, while different, are still used even by the most educated in today's society due to their convenience. All counting ultimately involves reference to something other than the things being counted. At first it may have been grains or pebbles but now it is a memorised sequence of words that happen to be the names of the numbers.

As anyone with even a passing interest in cultural institutions will know, art museums are adapting to keep up with changes in society. Do any of these newly developed spaces indicate a fundamental shift in the ways we engage with art at the beginning of the twenty-first century? The answer is a qualified Yes and also, it must be said, No. A clear sense of this can be gained by considering the 2003 redevelopment of the National Gallery of Victoria (NGV) in Melbourne, Australia’s second largest city, in the light of the aspirations embodied in the original building that served as its template.

The first building was considered a thoroughly modern museum when it opened to the public in 1968. We should not forget that it was also bold, entrepreneurial and innovative in ways that have done great credit to the vision and foresight of the architect, Roy Grounds. For one thing, the 1968 building signalled a strong sense of engagement with Asian and Pacific cultures, both in its architecture and through the layout of its collections. Its entrance lobby was designed to facilitate the rapid and efficient circulation of visitors. It also contained a series of greatly expanded temporary exhibition galleries and a vast Great Hall, which represented an unprecedented emphasis on the ancillary roles of corporate functions and public performances in the contemporary museum.

This last feature might have seemed excessive to some, yet how wise it has proven over the years as museums have come to place increasing emphasis on corporate sponsorship, and on the need to generate additional funds via room hire. Furthermore, the Great Hall has for forty years provided an area for children to roam at large before being escorted through the much less spatially accommodating galleries themselves. As an unintimidating introduction to the lifelong rigours of visiting art museums, its impact on attendance cannot be overestimated.

At the same time, other aspects of the 1968 NGV have not withstood the test of time so well. Foremost among these are the huge expanse of the exterior’s windowless wall and the surrounding moat, which creates a rather unwelcoming expression of the museum as a temple of culture set apart from the everyday world. Over time, this idea has been questioned, and has been superseded by the growing impetus towards the alternative model of the museum as a more open-ended and visitor-friendly forum that engages the public more effectively.

With these considerations in mind, Mario Bellini’s redeveloped NGV opened in 2003 and his design reflects what the new, improved, twenty-first century global museum feels it should be emphasising to its visitors. Here the institution’s energies are focused, not so much on the technical subtleties of how to design the galleries themselves, as on presenting to the public a spectacular image of the museum itself as a welcoming yet efficient facilitator of social interaction, popular entertainment and public knowledge. All of this is certainly impressive, but where has the art gone? We are not allowed to see the exhibitions until we have completed the necessary inductions. We are greeted by a hugely expanded cloakroom screening off our vision to the right, followed by a large visitor information office leading to the ticket booths. Above us is the cafe and to our left we cannot escape the NGV shop set alongside the exit.

And what of the redesigned galleries themselves? In fact, they represent a wonderfully elegant reframing of the permanent collections in ways that should offer first-time visitors and seasoned members alike many new avenues for engagement in the years to come. But herein lies the conundrum posed by the NGV renovation and by the global sweep of new museum projects more generally. The mainstay elements of a permanent collection can become all too easily lost in the increased prominence that these rebranding exercises tend to place on the more glamorously spectacular aspects of the institution itself. At its most extreme, this results in the construction of new buildings that supplant the artworks inside them to become the major attractions themselves.

These challenges are most keenly felt in the area of the temporary exhibition. Entrance to the NGV permanent collection is now free, so the NGV needs something to keep the paying public coming back. The answer lies in the international ‘blockbuster’ exhibition. The Impressionists, for example, netted a total of 380,000 visitors, making it one of the most popular exhibitions in Australian history. There has also been, it needs to be said, a commendable attempt to leaven the international masterpieces with selected highlights from the permanent collection. Overall, though, the prevalence of these ‘rental’ blockbusters cannot but help introduce a certain ‘off the rack’ feeling to the institution’s exhibition programme. More importantly perhaps, they clearly narrow the options for other worthy but less glamorous projects, and they take energy away from the curators’ potential to do further work on and around the permanent collection itself.

Yet the show must go on, and shows can’t exist without the public. Even the most adroit organisation, as the NGV assuredly is, needs to be able to juggle numerous, often conflicting priorities: the need to advance scholarship, on the one hand, versus the imperative of access on the other; the need to introduce audiences to new areas, versus the necessity of luring them in with instant brand recognition. Nobody said it was going to be easy, and the effect of too much innovation in museums can be disastrous.

Who studies children’s literature and what is it that they study? The answers to this question are complex and messy, because of the many confounding factors which exist in this field.

Firstly, unlike literature for adults, children’s literature is not generally written by its own readers. Adults write for children, and thus adult perceptions of what children are and of what they could and should become are woven into the literature.

Furthermore, some of those who study children’s literature (and those who write certain kinds of children’s books) are less interested in literary values than in the kinds of lessons it can teach- either in terms of creating better children or in terms of serving a particular curriculum. The issue of how a teacher can use a children’s book is often contentious, but even outside the classroom, much material for children is still didactic.

Thirdly, while almost all literature is currently promoted within a strong commercial matrix, children’s literature is often especially targeted for marketing initiatives. This fact means that readers are often recruited with a message that is negligibly literary and significantly oriented to ideas of consumption. Daniel Hade (2002) has raised useful questions about whether children’s experience of reading is altered when their books are part of a larger marketing framework involving the movie, the game, and the toy of a popular children’s book. How children perceive and respond to their stories in this new context is an important question.

It is also important to note that texts in an ever-increasing range of new media compete with print media for the attention of the child reader, and create definitional issues for scholars. Does the term ‘literature’ exclusively imply a verbal text? If not, where are the limits? Could a literary computer game ever be considered a work of literature? If not, what kind of attention should be paid to it, since children themselves undoubtedly perceive their print literature as part of a broader continuum? The internet provides one forum through which children now communicate with each other. (In 2003, the internet search engine Google listed 7,920,000 sites relating to the Harry Potter novels; even allowing for duplication and dead ends, that is a number with revolutionary implications.)

Finally, in the context of the higher education institutions where the formal study of children’s literature is often located, at least three disciplinary frameworks (English, education, and librarianship) fragment the focus of scholarly study of children’s literature.

How is the value of the imaginative encounter with the work of literature sustained and honored among such a welter of conflicting interests? One route through this maze is to ask the child readers for help. As David Lewis (2001) has perceptively noted, what children think of reading is not usually the same as what adults think, whether teachers or parents. As Lewis points out, children ‘sometimes see more and they often see differently’. If those who study reading can explore children’s perceptions as well as those of adults, their understanding of the nature of reading will be enhanced.

Lewis makes a further valid point when he adds that exploring children’s perceptions is usually justified for educational reasons: “It is true that a better understanding of how children read and how they learn to read, is a prerequisite to improved approaches to teaching. However, it can also be argued, as Lewis rightly does, that when children’s responses to literature are accessed and interpreted, they frequently lead to an understanding of how picture books appeal to children.

Young people’s accounts of what and how they read also enable a more sophisticated description of many of the complex processes involved in reading. All descriptions of reading runs the risk of solipsism: i.e. this is how I read so this is what reading is for everyone. Asking other readers how they read, however, reduces that risk. For example, if I am a strong visualizer as I read, I may consider that visualization is a key component of successful reading and I may judge books by their capacity to evoke a vivid visual response. Other readers, however, may help me to realize that not everyone reads with mental pictures. Some readers respond to the patterns of the words, ‘hearing’ them inaudibly like a subliminal radio program. Others respond to the patterns of feelings in the story, responding with an emotional connection. Talking to competent readers, of all ages, provides a better understanding of reading experiences.

Children’s insights are even more important when it comes to understanding the significance of print literature as one aspect of literary culture. Too often adults assume that reading any book at all is a more worthwhile experience than playing a digital game of any kind. A humbler approach would include asking why the game appeals to the player. Many adults will probably never develop the automatic skills to process a game as readily as they can read a book. This does not indicate that a book is better, but that a particular set of skills is absent. Non-players must acknowledge that some fictional universes are thus closed to them, and a logical response would be to find someone who can guide them to the pleasures and challenges of the gaming world. Games need to be judged individually just as books do, and any evaluative framework needs to take this into account.

Music has long been considered a uniquely human concept. In fact, most psychologists agree that music is a universal human instinct. Like any ability, however, there is great variation in people’s musical competence. For every brilliant pianist in the world, there are several people we refer to as ‘tone deaf’. It is not simply that people with tone deafness (or ‘amusia’) are unable to sing in tune, they are also unable to discriminate between tones or recognize familiar melodies. Such a ‘disorder’ can occur after some sort of brain damage, but recently research has been undertaken in an attempt to discover the cause of congenital amusia (when people are born with the condition), which is not associated with any brain damage, hearing problems, or lack of exposure to music.

According to the research of Dr. Isabelle Peretz of the University of Montreal, amusia is more complicated than the inability to distinguish pitches. An amusic (a person who has the condition of amusia) can distinguish between two pitches that are far apart, but cannot tell the difference between intervals smaller than a half step on the Western diatonic scale, while most people can easily distinguish differences smaller than that. When listening to melodies which have had a single note altered so that it is out of key with the rest of the melody, they do not notice a problem. As would be expected, amusics perform significantly worse at singing and tapping a rhythm along with a melody than do non-amusics.

The most fascinating aspect of amusia is how specific to music it is. Because of music’s close ties to language, it might be expected that a musical impairment may be caused by a language impairment. Studies suggest, however, that language and music ability are independent of one another. People with brain damage in areas critical to language are often still able to sing, despite being unable to communicate through speech. Moreover, while amusics show deficiencies in their recognition of pitch differences in melodies, they show no such deficiencies in tonal languages. Amusics who speak tonal languages, such as Chinese, do not report having any difficulty discriminating between words that differ only in their intonation. The linguistic cues inherent in speech make discrimination of meaning much easier for amusics. Amusics are also successful most of the time at detecting the mood of a melody, can identify a speaker based on his or her voice and can discriminate and identify environmental sounds.

Recent work has been focused on locating the part of the brain that is responsible for amusia. The temporal lobes of the brain, the location of the primary auditory cortex, have been considered. It has long been believed that the temporal lobes, especially the right temporal lobe, are most active when engaged in musical activity, so any musical disability should logically stem from here as well. Because it has been shown that there is no hearing deficit in amusia, researchers moved on to the temporal neocortex, which is where more sophisticated processing of musical cues was thought to take place. New studies, however, have suggested that the deficits in amusics are located outside the auditory cortex. Brain scans of amusics do not show any reaction at all to differences smaller than a half step. When changes in tones are large, their brains overreact, showing twice as much activity on the right side of the brain as a normal brain hearing the same thing. These differences do not occur in the auditory cortex, indicating again that the deficits of amusia lie not in hearing impairment, but in higher processing of melodies.

So what does this all mean? Looking only at the research of Peretz in the field of neuropsychology of music, it would appear that amusia is some sort of disorder. As a student of neurobiology, however, I am skeptical. Certainly the studies by Peretz that have found significant differences between the brains of so-called amusics and normal brains are legitimate. The more important question now becomes one of normality. Every trait from skin color to intelligence to mood exists on a continuum—there is a great deal of variation from one extreme to the other. Just because we recognize that basic musical ability is something that the vast majority of people have, this doesn’t mean that the lack of it is abnormal.

What makes an amusic worse off than a musical prodigy? Musical ability is culturally valued, and may have been a factor in survival at one point in human history, but it does not seem likely that it is being selected for on an evolutionary scale any longer. Darwin believed that music was adaptive as a way of finding a mate, but who needs to be able to sing to find a partner in an age when it is possible to express your emotions through a song on your iPod?

While the idea of amusia is interesting, it seems to be just one end of the continuum of innate musical ability. Comparing this ‘disorder’ to learning disorders like a specific language impairment seems to be going too far. Before amusia can be declared a disability, further research must be done to determine whether lack of musical ability is actually detrimental in any way. If no disadvantages can be found of having amusia, then it is no more a disability than having poor fashion sense or bad handwriting.

A  Leaf-cutting ants and their fungus 'farm' are a marvel of nature and perhaps the best-known example of symbiosis — the mutual dependence of two species. Ants cultivate a mushroom-like fungus in 'farms'. Both the ants and their so-called 'agriculture' have been extensively studied over the years, but recent research has uncovered intriguing new findings.

Ants invented agriculture 50 million years before people did, and the leaf-cutters, members of the large attine ant family, practise the most sophisticated example of it. They grow their fungus in underground chambers that can reach the size of a football. A single leaf-cutter nest may contain a thousand such chambers, embedded in an underground metropolis up to 18 feet deep, and support a society of more than a million ants.

B  These ant communities are the dominant plant-eaters of the Neotropics, the region comprising South and Central America, Mexico and the Caribbean. Biologists believe 15 percent of the leaf production of tropical forests disappears down the nests of leaf-cutter ants. In the nest, the leaves are shredded and added to the fungus, which digests the leaves and is in turn eaten by the ants. The attine ants' achievement is remarkable because it allows them to consume, courtesy of their mushroom's digestive powers, the harvest of tropical forests whose leaves are laden with poisonous chemicals.

C  There are more than 200 known species of the attine ant tribe, divided into 12 groups, or genera. The leaf-cutters use fresh vegetation; the other groups, known as the lower attines because their nests are smaller and their techniques more primitive, feed their gardens with similar leaves that have fallen on the ground and insects that lie on the forest floor. Lower attine ants are all a similar size. However, leaf-cutter worker ants come in made-to-fit sizes — large ants to saw off leaves, medium ones to shred them, and miniature workers to seed them with fungus and clean off alien growths.

D  In 1994, biologists from the United States Department of Agriculture analysed the DNA of ant fungi. They found that the leaf-cutters' fungus was descended from a single pure strain, propagated for at least 23 million years. However, the fungi grown by lower attine ants fell into four different groups, as if the ants had domesticated wild fungi at least four times in evolutionary history. What could be driving these two patterns of fungus gardening — the pure clone cultivation of the leaf-cutters and the multiple varieties of the lower attines?

E  The answer has been suggested by Cameron Currie of the University of Toronto. The pure strain of fungus grown by the leaf-cutters, it seemed to him, resembled the single crops grown by humans to the exclusion of all others, such as potato growing. These 'monocultures', which lack the genetic diversity to respond to changing environmental threats, are particularly vulnerable to parasites — organisms that live and feed on their host, often causing harm. Currie felt there had to be a parasite in the ant-fungus system. But a century of ant research had provided no evidence for his idea. Textbooks describe how leaf-cutter ants scrupulously weed their gardens of all foreign organisms. "People kept telling me the ants keep their gardens free of parasites," said Currie. Nevertheless, after three years of sifting through attine ant gardens, Currie discovered several alien organisms, particularly a family of parasitic moulds called 'Escovopsis'.

F  Escovopsis is a deadly disease that can devastate a fungus garden in a couple of days. It blooms like a white cloud which envelops the whole garden. Other ants won't go near it, and the ants associated with the garden just starve to death. Evidently, the ants usually manage to keep Escovopsis and other parasites under control. Nevertheless, with any lapse in control Escovopsis will quickly burst forth. Although new leaf-cutter gardens start off free of Escovopsis, within two years some 60 percent become infected.

G  The discovery of Escovopsis's role brings a new level of understanding to the evolution of the attine ants. In the last decade, evolutionary biologists have been increasingly aware of the role of parasites as driving forces in evolution. With Currie's work, there is now a possible reason for the different varieties of fungus in the lower attine mushroom gardens — to stay one step ahead of the relentless Escovopsis. Interestingly, the leaf-cutters had, in general, fewer alien moulds in their gardens than the lower attines, yet more Escovopsis infections. Clearly, the price they pay for cultivating a pure variety of fungus is a higher risk from Escovopsis.

H  So how do attine ants keep this parasite under control? People have known for a hundred years that ants have a whitish growth on their body surface. It was thought to be wax but, after examining it under a microscope, Currie discovered a specialised patch on the ants' bodies that harbours a particular kind of bacterium, one well known to the pharmaceutical industry and the source of half the antibiotics used in medicine. This bacterium is a potent poisoner of Escovopsis, inhibiting its growth and suppressing spore formation. Astoundingly, the leaf-cutter ants are accomplishing feats beyond the power of humans: they are growing a monocultural crop year after year without disaster, and they are using an antibiotic apparently so wisely that, unlike people, they are not provoking antibiotic resistance in the target disease-producing organism.

A  In the ancient world, the waxy grey substance we now refer to as ambergris was highly prized for its medicinal properties, and was widely used as a spice, which was believed to be an aphrodisiac when added to food or wine. Ambergris itself is pleasantly aromatic, especially when warmed, and it was also highly valued as a fixing agent in the making of perfume, since it enabled a scent to retain its fragrance for much longer than might otherwise have been possible. Most ambergris was found in the form of lumps floating on the surface of the sea, or washed up on the shores of tropical and temperate oceans. At one time, ambergris was worth its weight in gold, but there was much confusion about its origins.

B  Ambergris was known to the Arabs as 'anbar' and was originally called amber in the West in the Middle Ages. This eventually led to further confusion in the popular mind between ambergris and true amber, the mineral known to mineralogists as succinite, which is actually fossilised tree resin, and generally yellow in colour. Both substances were rare and costly, and both were associated with the sea, largely because for Europeans the most common source of amber was the shores of the Baltic. In Chapter 92 of Moby Dick, the American writer Herman Melville pours scorn on those who believed the two substances to be the same: 'Though the word ambergris is but the French compound for grey amber, yet the two substances are quite distinct. For amber, though at times found on the sea-coast, is also dug up in some far-inland soils, whereas ambergris is never found except upon the sea. Besides, amber is a hard, transparent, brittle, odourless substance, used for mouth-pieces to pipes, for beads and ornaments; but ambergris is soft, waxy, and so highly fragrant that it is largely used in perfumery.'

C  Moby Dick was published in 1851, by which time the mystery of the origins of ambergris had been resolved by the scientific community. In 1783, the botanist Joseph Banks, who had accompanied Captain James Cook on his voyages of discovery in the Pacific, presented a paper to the Royal Society of London by the German physician Dr Franz Xavier Schwediawer in which it was conclusively proved that ambergris came from sperm whales. In this, he was confirming an observation made in the 13th century by the great Venetian traveller Marco Polo who, while on the island of Socotra in the Indian Ocean, had witnessed a sperm whale vomiting up ambergris. But whereas Marco Polo imagined that the whale had swallowed the lump in the depths of the sea, Schwediawer showed that the origin of the material was inside the whale itself.

D  The sperm whale is the largest of the odontocetes, or toothed whales. Males can grow up to 20 metres in length. Melville described the sperm whale as 'the king of whales', and his novel Moby Dick is based on the pursuit of one such creature. Sperm whales are renowned for their ability to dive to great depths, possibly as far as 3,000 metres below the surface, and for remaining underwater for periods of two hours or more in pursuit of their favourite prey, the giant squid.

E  It is from the problems the whales have in digesting the beaks of such creatures that ambergris has its origins. The beak is sharp and irritates the whale's lower intestine, which responds by producing a black, foul-smelling liquid. It is not clear to scientists whether this secretion should be considered a normal response by the whale's digestive system or a pathological one, but from time to time large quantities of the liquid are vomited up by the whale. Once outside the whale's body and exposed to air, the substance hardens, acquiring the waxy, greyish and pleasantly aromatic characteristics of ambergris. Often the beaks of squid are still found embedded in lumps of ambergris, some of which can weigh several hundred kilograms. Melville took some delight in contrasting the origins of ambergris with the high value placed upon it by refined society: 'Who would think, then, that such fine ladies and gentlemen should regale themselves with an essence found in the inglorious bowels of a sick whale!'

F  Sperm whales were ruthlessly pursued by commercial whalers in the 19th and 20th centuries. In 1963-64 alone, almost 30,000 individuals were killed, and only the imposition of a ban on the hunting of sperm whales in 1984 saved the species from extinction. Ambergris was by far the most valuable product to be extracted during the processing of the whales' carcasses, and over 90 per cent of the annual worldwide total was acquired in this way, as a by-product of commercial whaling. However, even before the ban on hunting sperm whales was imposed, the 1972 Marine Mammal Protection Act had prohibited trade in ambergris. Just as petroleum and plastic products were replacing other natural products of whaling, so ambergris was supplanted in the making of perfume by other materials, some natural and some synthetic in origin. Nevertheless, it is possible that, as sperm-whale populations recover to their former numbers in the wild, so the sight of lumps of ambergris washed ashore along the tide-line will once again become a familiar one to beach-combers the world over.

A  Linkages between the Agri-Food Sector and Tourism offer significant opportunities for the development of both sectors within the region. These linkages could lead to ensuring the sustainability of the region's tourism product thus ensuring its preservation. Agriculture and tourism - two of Wisconsin's most important industries - are teaming up in southwestern Wisconsin. A pilot project has found that tourists, rural communities, and some farmers could benefit from stronger efforts to promote and market agricultural tourism there. In 1990, agricultural tourism project members surveyed 290 visitors to the annual Monroe Cheese Festival and 164 visitors to the Picnic on the Farm, a one-time event held in Platteville in conjunction with the Chicago Bears summer training camp. More than one-half of those surveyed responded favorably to a proposed tour, saying they would be interested in participating in some type of agricultural tour in southwestern Wisconsin. Survey respondents reported that they would prefer to visit cheese factories, sausage processing plants, dairy farms, and historical farm sites, as well as enjoy an old-fashioned picnic dinner. The study also found strong interest in visiting specialty farms (strawberries, cranberries, poultry, etc.). More than 75 percent of the Cheese Day visitors planned ahead for the trip, with 37 percent planning at least two months in advance.

B  More than 40 percent of the visitors came to Monroe for two- or three-day visits. Many stopped at other communities on their way to Cheese Days. Visitors at both events indicated that they were there to enjoy themselves and were willing to spend money on food and arts and crafts. They also wanted the opportunity to experience the "country" while there. The study found that planning around existing events should take into account what brought visitors to the area and provide additional attractions that will appeal to them. For example, visitors to Cheese Days said they were on a holiday and appeared to be more open to various tour proposals. Picnic visitors came specifically to see the Chicago Bears practice. They showed less interest in a proposed agricultural tour than Cheese Day visitors, but more interest in a picnic dinner.

C  The study identified three primary audiences for agricultural tourism: 1) elderly people who take bus tours to see the country; 2) families interested in tours that could be enjoyed by both parents and children; and 3) persons already involved in agriculture, including international visitors. Agricultural tourism can serve to educate urban tourists about the problems and challenges facing farmers, says Andy Lewis, Grant county community development agent. While agriculture is vital to Wisconsin, more and more urban folk are becoming isolated from the industry. In fact, Lewis notes, farmers are just as interested in the educational aspects of agricultural tours as they are in any financial returns.

D  "Farmers feel that urban consumers are out of touch with farming," Lewis says. "If tourists can be educated on issues that concern farmers, those visits could lead to policies more favorable to agriculture." Animal rights and the environment are examples of two issues that concern both urban consumers and farmers. Farm tours could help consumers get the farmer's perspective on these issues, Lewis notes. Several Wisconsin farms already offer some type of learning experience for tourists. However, most agricultural tourism enterprises currently market their businesses independently, leading to a lack of a concerted effort to promote agricultural tourism as an industry.

E  Lewis is conducting the study with Jean Murphy, assistant community development agent. Other participants include UW-Platteville Agricultural Economist Bob Acton, the Center for Integrated Agricultural Systems, UW-Extension Recreation Resources Center, the Wisconsin Rural Development Center, and Hidden Valleys, a Southwestern Wisconsin regional tourism organization. This past fall, Murphy organized several workshops with some Green and Grant County farmers, local business leaders, and motor coach tour operators to discuss how best to organize and put on farm tours. Committees were formed to look at the following: tour site evaluations, inventory of the area's resources, tour marketing, and familiarization of tours. The fourth committee is organizing tours for people such as tour bus guides and local reporters to help better educate them about agricultural tourism. Green County farmers already have experience hosting visitors during the annual Monroe Cheese Days. Green County Tourism Director Larry Lindgren says these farmers are set to go ahead with more formal agricultural tours next year. The tours will combine a farm visit with a visit to a local cheese factory and a picnic lunch.

F  Another farm interested in hosting an organized tour is Sinsinawa, a 200-acre Grant County farm devoted to sustainable agriculture and run by the Dominican Sisters. Education plays a major role at the farm, which has an orchard, dairy and beef cows, and hogs. Farm tours could be combined with other activities in the area such as trips to the Mississippi River and/or visits to historical towns or landmarks, Lewis says. The project will help expose farmers to the tourism industry and farm vacations as a way to possibly supplement incomes, he adds. While farm families probably wouldn't make a lot of money through farm tours, they would be compensated for their time, says Lewis. Farmers could earn additional income through the sale of farm products, crafts, and recreational activities.

A  Researchers and designers around the globe continue to create new technologies that, by honoring the tenets of life, are both highly efficient and often environmentally friendly. And while biomimicry is not a new concept (Leonardo da Vinci looked to nature to design his flying machines, for example, and pharmaceutical companies have long been mimicking plant organisms in synthetic drugs), there is a greater need for products and manufacturing processes that use a minimum of energy, materials, and toxins. What's more, due to technological advancements and a newfound spirit of innovation among designers, there are now myriad ways to mimic Mother Nature's best assets.

B  "We have a perfect storm happening right now," says Jay Harman, an inventor and CEO of PAX Scientific, which designs fans, mixers, and pumps to achieve maximum efficiency by imitating the natural flow of fluids. "Shapes in nature are extremely simple once you understand them, but to understand what geometries are at play, and to adapt them, is a very complex process. We only just recently have had the computer power and manufacturing capability to produce these types of shapes."

C  Harman is tinkering with a number of bioinspired products: an impeller that reduces the need for certain chemicals now used in municipal water reservoirs; medical devices that can pump blood more rapidly without destroying blood cells; and near-silent air conditioners that are 25 percent more efficient than the average window unit. His company is also working with the largest manufacturer of residential ventilation products, Broan-NuTone, to devise quiet, energy-efficient kitchen and bathroom fans.

D  "If we could capture nature's efficiencies across the board, we could decrease dependency on fuel by at least 50 percent," Harman says, "What we're finding already with the tools and methodology we have right now is that we can reduce energy consumption by between 30 and 40 percent."

E  Despite these potential energy savings, Harman says, he's long faced stubbornness among industry engineers, who believed efficiency was synonymous with the sort of cookie-cutter design and manufacturing that's been around since the industrial revolution. It's only recently that mainstream companies have begun to equate biomimicry with the bottom line. DaimlerChrysler, for example, introduced a prototype car modeled on a coral reef fish. Despite its boxy, cube-shaped body, which defies a long-held aerodynamic standard in automotive design (the raindrop shape), the streamlined boxfish proved to be aerodynamically ideal and the unique construction of its skin—numerous hexagonal, bony plates—a perfect recipe for designing a car of maximum strength with minimal weight.

F  Companies and communities are flocking to Janine Benyus, author of the landmark book Biomimicry: Innovation Inspired by Nature (Perennial, 2002) and cofounder of the Biomimicry Guild, which seats biologists at the table with researchers and designers at companies such as Nike, Interface carpets, Novell, and Procter & Gamble. Their objective is to marry industrial problems with natural solutions. The Helena, Montana-based consultancy also offers a headhunting service for companies seeking inspiration from nature or to put biologists on the payroll. The guild, which presents companies with natural models in hopes of encouraging sustainable business practices, also flags substances that might soon be banned and presents companies with scientific research regarding benign, natural alternatives.

G  Benyus, who hopes companies will ultimately transcend mere product design to embrace nature on a more holistic level, breaks biomimicry into three tiers. On a basic (albeit complicated) level, industry will mimic nature's precise and efficient shapes, structures, and geometries. The microstructure of the lotus leaf, for example, causes raindrops to bead and run off immediately, while self-cleaning and drying its surface—a discovery that the British paint company Sto has exploited in a line of building paints. The layered structure of a butterfly wing or a peacock plume, which creates iridescent color by refracting light, is being mimicked by cosmetics giant L'Oreal in a soon-to-be-released line of eye shadow, lipstick, and nail varnish. The branchlike structure of bronchial tubes in human lungs inspired engineers at Morgan Fuel Cells to invent an efficient solution for administering oxygen and hydrogen gas flow in fuel cells.

H  The next level of biomimicry involves imitating natural processes and biochemical 'recipes': Engineers and scientists are now looking at the nasal glands of seabirds to solve the problem of desalination; the abalone's ability to self-assemble its incredibly durable shell in water, using local ingredients, has inspired an alternative to the conventional, and often toxic, 'heat, beat, and treat' manufacturing method. How other organisms deal with harmful bacteria can also be instructive: Researchers for the Australian company Biosignal, for instance, observed a seaweed that lives in an environment teeming with microbes to figure out how it kept free of the same sorts of bacterial colonies, called biofilms, that cause plaque on your teeth and clog up your bathroom drain. They determined that the seaweed uses natural chemicals, called furanones, that jam the cell-to-cell signaling systems that allow bacteria to communicate and gather. Most antibacterial products on the market, such as soaps and coatings for contact lenses, are eventually susceptible to bacterial resistance, which is why Biosignal is now working to develop products that incorporate furanones in a wide range of applications, from medical equipment to cosmetics.

I  Ultimately, the most sophisticated application of biomimicry, according to Benyus, is when a company starts seeing itself as an organism in an economic ecosystem that must make thrifty use of limited resources and creates symbiotic relationships with other like organisms. A boardroom approach at this level begins with imagining any given company, or collection of industries, as a forest, prairie, or coral reef, with its own 'food web' (manufacturing inputs and outputs) and asking whether waste products from one manufacturing process can be used, or perhaps sold, as an ingredient for another industrial activity. For instance, Geoffrey Coates, a chemist at Cornell, has developed a biodegradable plastic synthesized from carbon dioxide and limonene (a major component in the oil extracted from citrus rind) and is working with a cement factory to trap their waste CO2 and use it as an ingredient.

J  Zero Emissions Research and Initiatives (ZERI), a global network of scientists, entrepreneurs, and educators, has initiated ecoindustrial projects that attempt to find ways to reuse all wastes as raw materials for other processes. Storm Brewing in Newfoundland, Canada — in one of a growing number of projects around the world applying ZERI principles — is using spent grains, a by-product of the beer-making process, to make bread and grow mushrooms.

K  As industries continue to adopt nature's models, entire manufacturing processes could operate locally, with local ingredients — like the factories that use liquefied beach sand to make windshields. As more scientists and engineers begin to embrace biomimicry, natural organisms will come to be regarded as mentors, their processes deemed masterful. And our culture at large will be more likely to see nature not as an exploitable resource, but as a source of information that's worth protecting.

A  Most species use camouflage to some extent. If they are convincing, they survive to pass their genes on to future generations. After generations of natural selection, animals can develop astonishingly complex camouflage techniques, manipulating shape, colour and movement. 'The principle of camouflage is to make it economically unviable for a predator to pursue a particular species of prey.' explains Professor Mark Elgar, of the University of Melbourne. 'Camouflage increases the search time and, as a consequence, the predator will simply target another species, either because it doesn't see the camouflaged individual or it just finds something more obvious to do.

B  The easiest way for an animal to disguise itself is to be invisible in its surroundings. To that end, stick and leaf insects have evolved complex camouflage to hide themselves from predators. Many have the texture of sticks or dry leaves, while others imitate living foliage, even the veins in a leaf. Some insects develop blemishes to match the spots caused by disease. A convincing appearance only works if its owner also acts the part, so during the day the creature using this type of camouflage keeps motionless, or sways like a dead leaf in the breeze. If disturbed, it falls to the ground and stays still. Entomologist Paul Zborowski, who has spent decades photographing inconspicuous creatures, rates the desert insects of Central Australia as the most convincingly disguised creatures he's seen. 'It's an incredibly old habitat so the creatures have had a long time to adapt,' Zborowski explains. Most of them behave like stones and don't move all day feeding only at night.

C  A tawny frogmouth sitting motionless on a stump also illustrates the importance of pairing a persuasive costume with behaviour. Professor Gisela Kaplan of the University of New England, in Australia, says the frogmouth's skill at camouflaging is learned behaviour. While adopting a pose may be a reflex of the bird, and can be observed in a hatchling's first week, the ability to choose a backdrop which matches its colouration does not develop for 4 – 6 months. When the chicks land, they are usually highly conspicuous, and their parents try to signal to them to move to a safe location.

D  Fixed camouflage is only good against a relatively unchanging environment, so some animals, such as the cuttlefish, have evolved an adaptable disguise. The cuttlefish can almost instantly change its colour, pattern and texture to match its surroundings, using specialised cells and muscles. On Queensland's reefs, scientists have been studying another ocean dweller that uses colour change, although not to blend into the surroundings. Dr Karen Cheney, from the University of Queensland, says the bluestriped fangblenny alters its colouration to mimic other species of fish, allowing it to travel with them and benefit from safety in numbers.

Its most impressive impersonation is of the black-with-neon-blue striped cleaner wrasse which eats the parasites on larger fish. Not only does the fangblenny benefit from the reduced predation that comes with the wrasse's beneficial relationships with other fish, but the disguise also lets it get closer to prey. It darts out from the safety of the wrasse's cleaning station to nip at unsuspecting fish passing by but doesn't attack those coming to be cleaned.

E  The most famous form of mimicry, however, is for defence, not attack, Batesian mimicry refers to animals that gain protection from predators by imitating a dangerous organism, often using conspicuous colours. The nineteenth-century naturalist Henry Bates first suggested this camouflage technique after noticing that several Amazonian butterfly species looked the same. The technique was later called after him. In Australian waters, the harmless harlequin snake eel sports the same black and white bandings as the highly toxic yellow-lipped sea krait, ensuring no predator will attack. However, the success of Batesian mimicry depends on the ratio of mimics to originals. If a predator encounters too many that are edible, it will just assume none of the animals with those markings are dangerous, explains Martyn Robinson, an educational naturalist with the Australian Museum.

F  An imitation of a more dangerous creature needn't be exact, just enough to make potential predators hesitate. The hawk moth caterpillar has markings resembling a snake's eyes on its abdomen. When confronted, the caterpillar pulls its head in and the eyes' flash open. Whether the potential predator thinks it has seen a snake, or is simply startled is unclear, but the outcome is that the caterpillar lives to see another day.

G  In Queensland's Tablelands, the chameleon gecko has another way of making predators hesitate. Its body is brown, but its tail is banded in black and white. Robinson explains that if attacked, the chameleon gecko will drop off its tail, which will wriggle around on the ground. Many lizards do this, but in the case of the chameleon gecko the tail bones actually rub against one another, so it squeaks. 'The predator is, of course, thoroughly absorbed by this black-and-white-striped, wriggling, squeaking thing on the ground, and the gecko can sneak away,' Robinson says, It's a one-time-only trick: the regrown tail is brown, the same as the gecko's body. Such precise disguise and elaborate trickery illustrate the limitless possibilities of nature. But, as Robinson points out, only the most successful illusionists are here to tell the tale.

A  Ever had a song stuck in your head, playing on an endless loop? Scientists call them 'involuntary musical images', or 'earworms', and a wave of new research is shining light on why they occur and what can be learned from them. Some neuroscientists and cognitive psychologists are studying earworms to explore the mysteries of memory and the part of the brain that is beyond our conscious control. 'The idea that we have full control over our thought processes is an illusion,' says psychologist Lauren Stewart, who founded the master's program in music, mind and brain at Goldsmiths, University of London, UK, where recent research has taken place. Researchers haven't been able to watch what happens in the brain when earworms occur, because they happen unpredictably. Much of what is known about them comes from surveys, questionnaires, diaries and lab experiments.

B  A Goldsmiths study published in the journal Memory and Cognition this year showed that the singing we hear in our heads tends to be true to actual recordings. Researchers had 17 volunteers tap to the beat of any earworm they heard during a four-day period while a device attached to their wrist recorded their movements. The tapping tempos were within 10% of the tempos of the original recordings. Another Goldsmiths study, published this year in Consciousness and Cognition, found that people who report hearing earworms often, and find them most intrusive, have slightly different brain structures, with more gray matter in areas associated with processing emotions.

C  Studies also show that the music in our heads often starts playing during times of 'low cognitive load', such as while showering, getting dressed, walking, or doing chores. Dr Stewart likens earworms to 'sonic screensavers' that keep the mind entertained while it is otherwise unoccupied. She and her colleagues tested that theory by having volunteers listen to songs and giving them various tasks afterwards. The volunteers who sat idly for the next five minutes were the most likely to report hearing the music in their heads. Dr Stewart observed that the more challenging the activity, the less likely the volunteers were to hear the music. Diary studies also show songs tend to match people's moods and therefore they are not random. If you are energized and upbeat, an earworm that occurs is likely to be uptempo too.

D  Songs the brain fixates on are usually those it has been exposed to recently, surveys show, which is why tunes getting heavy radio play frequently top the earworm charts. Even tunes you may have heard but didn't pay attention to can worm their way into your subconscious, says Ira Hyman, a psychologist at Western Washington University in Bellingham, USA. In an unpublished study there, participants who listened to music while doing other tasks were more likely to report that the songs returned as earworms later on, compared with participants who simply listened.

E  Some earworms are just fragments of a song that repeat like a broken record. So, when the mind hits a part of a song it can't remember, it loops back rather than moving on. That could make an earworm even more entrenched, Dr Hyman says. According to a theory known as the Zeigarnik effect, named for a Soviet psychologist, Bluma Zeigarnik, unfinished thoughts and activities weigh on the mind more heavily than those that are completed, although experiments exposing students to interrupted songs have yielded mixed results.

F  Researchers say they can't pinpoint a spot in the brain where earworms live. Imaging studies by Andrea Halpern at Bucknell University, in Lewisburg, USA, have shown that deliberately imagining music and actually listening to music activate many of the same neurological networks. Dr Halpern's earlier studies showed that when subjects listened to the first few notes of familiar music, areas in the right frontal and superior temporal portions of the brain became activated, along with the supplementary motor area at the top, which is typically involved in remembering sequences. When the same subjects listened to unfamiliar music and were asked to recall it, there was activity in the left frontal portions of the brain instead.

G  One factor that makes some songs stick might be repetition. 'Repetition leads to familiarity which leads to anticipation, which is satisfied by hearing the song,' says John Seabrook, author of The Song Machine: Inside the Hit Factory, about how producers pump pop songs full of aural 'hooks', the punchy melodic phrases designed to target the brain and leave it wanting more. The researchers are comparing the melodic structure of 100 often-mentioned songs with 100 similarly popular songs that weren't cited as earworms, to assess the difference. Songs with earworm potential appear to share certain features: a repeating pattern of ups and downs in pitch, and an irregular musical interval.

H  The researchers plan next to test their results in reverse, and play ringtones from songs of both the earworm and non-earworm variety for volunteers several times a day to see which ones get stuck. Drs Stewart and Halpern are now working together to recruit survey participants for a study looking at whether people at different stages of life experience earworms differently. 'You can argue that older people might get them more often because they know more songs,' Dr Halpern says. 'But the few responses we have so far indicate that they have earworms less often. It could be that they don't play music as often as younger people do.'

A  For farmers, working out the optimal amount of seed, fertiliser, pesticide and water to scatter on a field can make, or break, the subsequent harvest. Regular laboratory analyses of soil and plant samples from various parts of the field can help - but such expertise is costly, and often unavailable. However, a new and cheaper method of doing this analysis is now on offer. Precise prescriptions for growing crops can be obtained quickly, and less expensively, by calculating the amount of electromagnetic radiation reflected from agricultural land. The data is collected by orbiting satellites.

B  Examining the wavelength of the radiation that is reflected can reveal, with surprising precision, the properties of the soil, the quantity of crop being grown, and the levels in those crops of chlorophyll*, various minerals, moisture and other indicators of their quality. If recent and forecast weather data is added to the mix, detailed maps can be produced indicating exactly how, where and when crops should be grown. The service usually costs less than US$15 per hectare for a handful of readings a year, and can increase yields by as much as 10%.

C  Such precision farming using satellite-based intelligence is a relatively new technique. Even so, it is catching on quickly. Five times a year, for example, a French cereal-growers' co-operative called Sevépi purchases satellite data and makes it available to its members in the form of maps of their fields, divided into three or four colour-coded zones per hectare. For each zone, one of about 50 fertiliser formulas is recommended. On top of this, if the wheat in the field has already grown quite high early in the season, and heavy showers are expected, an appropriate dose of growth regulator is recommended for each zone. (Long, fragile stems break more easily in downpours.) Then, farm vehicles equipped with global-positioning system locators automatically mix and apply the prescribed dose to each area.

D  France is the pioneer in this sort of surveillance. More farmland is analysed by satellite there than in any other country, according to Infoterra (a subsidiary of EADS Astrium), the firm that is France's largest provider of such information, supplying data to companies such as Sevépi. Moreover, Henri Douche, head of Infoterra's agriculture sales in Toulouse, reckons the amount of monitored farmland will increase as weather patterns change and farmers can no longer rely on the past as a guide to the future. When confounded by the yield variations that these new weather patterns will bring, even farmers who are afraid of new technology will sign up, he says.

E  Inexpensive data on the productivity of land is advantageous to governments, too. Areas where fertilisers and pesticides are being applied excessively can be pinpointed, studied and regulated by environmental and land-use agencies. Guy Lafond, an agronomist with Agriculture and Agri-Food Canada, a government agency, says the satellite data it purchases is proving useful for the study of fields with declining productivity in the province of Saskatchewan. Overkill with nitrate fertilisers (which are also a source of greenhouse gases) appears partly responsible. And according to RapidEye, a German satellite operator, insurance companies are also studying satellite data with a view to selling insurance policies to governments of famine-prone countries that might be threatened by crop failure.

F  In March, RapidEye began selling data that helps forecast harvests. 'Too often, farmers limit productivity by managing fields uniformly,' says Fredrick Jung-Rothenhaüsler, head of product development at the firm's headquarters in Brandenburg an der Havel. 'Our satellites are the first commercial satellites to include the Red-Edge band of the light spectrum, which is sensitive to changes in chlorophyll content. More research will be necessary to realise the full potential of the Red-Edge band. However, this band can assist in monitoring vegetation health, improving species separation and also help in measuring protein and nitrogen content in biomass.' The company's data, which comes from both Europe and the Americas, breaks field productivity down into patches just five metres square.

G  The advantages that satellite technology provides in terms of precision farming do not have to be restricted to rich countries. In Africa, where many soils have become badly depleted of nutrients, better fertiliser management would greatly improve the situation. As a consequence, the charitable trust World Agroforestry Centre, in the city of Nairobi, in Kenya, has begun to build up a catalogue of the radiation patterns derived from around 100,000 samples of African soils. The information is the key to understanding the potential of these soils to be more agriculturally productive. Once passed on to the International Centre for Tropical Agriculture, based in Colombia, South America, it is intended that the information be used to build a database called the 'Digital Soil Map'. When ready, this will provide farmers with free forecasts, developed with regularly updated satellite imagery, across farmland in a number of countries in Africa. This is information which will almost certainly assist in improving crop yields. For a hunger-ravaged continent, that is good news indeed.

* chlorophyll: the green substance in plants that allows them to absorb sunlight