Reading Test 29
Save the Turtles (Leatherback turtles)
A
Leatherback turtles follow the general sea turtle body plan of having a large, flattened, teardrop-shaped body with rows of very large flippers and a short tail. Unlike other sea turtles, the leatherback’s flattened forelimbs are adapted for swimming in the open ocean. Claws are absent from both pairs of flippers. The Leatherback’s flippers are the largest in proportion to its body size among sea turtles. Leatherbacks’ front flippers can grow up to 2.7 metres (9 ft) in large specimens, the largest flippers (even in comparison to its body) of any sea turtle. As the last of the living species of Dermochelyids, the leatherback turtle has several distinguishing characteristics that differentiate it from other sea turtles. Its most notable feature is that it lacks the bony carapace of the other extant sea turtles.
B
During the past month, four Leatherbacks have washed up along Irish coasts from Wexford to Kerry. These turtles are more typical of warmer waters and only occur in Irish waters when they are off course. It is likely that these turtles are migrating opportunistically from America. Two specimens have been taken to Coastal and Marine Resources Centre (stored at the National Maritime College), University College Cork, where a necropsy (post mortem for animals) will be conducted to establish their age, sex and their exact origin. During this same period, two Leatherback turtles were found in Scotland; and a rare Kemp’s Ridley turtle was found in Wales, so actually there has been an increase in the number of vagrant turtles in Ireland and the UK.
C
Actually, there has been extensive research conducted regarding the sea turtles’ abilities to navigate. Leatherbacks rely upon ocean currents for migration when they are far away. In the water, their path is greatly affected by powerful currents. Despite their limited vision, and lack of landmarks in the open water, turtles are able to retrace their migratory paths. Some explanations of this phenomenon have found that sea turtles can detect the angle and intensity of the earth’s magnetic fields.
D
The majority of Leatherbacks are non-parental, normally found in Irish waters, because the temperatures here are far too cold for their survival. Instead, adult loggerheads prefer the warmer waters of the Mediterranean and the North American east coast. The four turtles that were found have probably originated from the North American population of loggerheads. However, to provide further genetic analysis to confirm this assumption it is hoped that DNA analysis will be carried out at the Coastal and Marine Resources Centre. Since the turtles probably began their lives near the North Atlantic Gyre (a giant circular ocean current) that takes them from America to Europe (Azores), and then Irish waters, many Leatherbacks (especially hatchlings) are more likely to arrive via a different current. This remarkable round trip may take many years before completion. They are believed to spend several intermediate years in the open seas between Europe and the North Atlantic served waters before they settle in the coastal waters of Florida or the Caribbean.
E
The four turtles were probably on their way back toward the Atlantic when they strayed a bit too far north of the Gulf Stream. Once they did, their fate was sealed, as the cooler waters of the North Atlantic affect their physiology (causing them to become lethargic in our seas). Once in cool waters, the survival odds of a loggerhead begins to shut down as they get “cold-stunned.”
F
Leatherbacks are in imminent danger of extinction. A critical factor (among others) is the harvesting of eggs for human profits. Valued as a food delicacy, Leatherback eggs are falsely understood to have aphrodisiacal properties in some cultures. The Leatherback, unlike the Green Sea turtle, is often killed for its meat; however, the increase in human populations coupled with the growing black market trade has escalated their egg depletion. Other critical factors causing the Leatherbacks’ decline are pollution such as plastics (leatherbacks eat this debris thinking it is jellyfish), fishing practices such as longline fishing and gill nets, and development on habitat areas. Scientists have estimated that there are only about 35,000 Leatherback turtles in the world.
G
We are often unable to understand the critical impact a species has on the environment—that is, until that species becomes extinct. Even if we do not know the role a creature plays in the health of the environment, past lessons have taught us enough to know that every animal and plant is one important link in the integral chain of nature. Some scientists now speculate that the Leatherback may play an important role in the recovery of diminishing fish populations. Since the Leatherback consumes its weight in jellyfish per day, it helps to keep Jellyfish populations in check. Jellyfish consume large quantities of fish larvae. The rapid decline in Leatherback populations over the last 50 years has been accompanied by a significant increase in jellyfish and a marked decrease in fish in our oceans. Saving sea turtles is an International endeavor.
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Bestcom Considerate Computing
A
‘Your battery is now fully charged,’ announced the laptop to its owner Donald A. Norman in a synthetic voice, with great enthusiasm and maybe even a hint of pride. For the record, humans are not at all unfamiliar with distractions and multitasking. ‘We are used to a complex life that gets constantly interrupted by computer’s attention-seeking requests, as much as we are familiar with procreation,’ laughs Ted Selker of the Massachusetts Institute of Technology (MIT) Media Lab.
B
Humanity has been connected to approximately three billion networked telephones, computers, traffic lights and even fridges and picture frames since these things can facilitate our daily lives. That is why we do not typically turn off the phones, shut down the e-mail system, or close the office door even when we have a meeting coming or a stretch of concentrated work. We merely endure the consequences.
C
Countless research reports have confirmed that if people are unexpectedly interrupted, they may suffer a drop in work efficiency, and they are more likely to make mistakes. According to Robert G. Picard from the University of Missouri, it appears to build up the feeling of frustration cumulatively, and that stress response makes it difficult to focus again.
It is not solely about productivity and the pace of life. For some professionals like pilots, drivers, soldiers and doctors, loss of focus can be downright disastrous. ‘If we could find a way to make our computers and phones realise the limits of human attention and memory, they may come off as more thoughtful and courteous,’ says Eric Horvitz of Microsoft Research. Horvitz, Selker and Picard are just a few of a small but prospering group of researchers who are attempting to make computers, phones, cars and other devices to function more like considerate colleagues instead of egocentric oafs.
D
To do this, the machines need new skills of three kinds: sensing, reasoning and communicating. First, a system must: sense or infer where its owner is and what he or she is doing. Next, it must weigh the value of the messages it wants to convey against the cost of the disruption. Then it has to choose the best mode and time to interject. Each of these pushes the limits of computer science and raises issues of privacy, complexity or reliability. Nevertheless, ‘Attentive’ Computing Systems, have started to make an appearance in the latest Volvos, and IBM has designed and developed a communications software called WebSphere that comes with an underlying sense of busyness. Microsoft has been conducting extensive in-house tests of a way more sophisticated system since 2003. In a couple of years, companies might manage to provide each office employee with a software version of the personal receptionist which is only available to corner-suite executives today.
E
However, the truth is that most people are not as busy as they claim to be, which explains why we can often stand interruptions from our inconsiderate electronic paraphernalia. To find out the extent to which such disruption may claim people’s day time, an IBM Research team led by Jennifer Lai from Carnegie Mellon University studied ten managers, researchers and interns at the workplace. They had the subjects on videotape, and within every period of a specific time, they asked the subjects to evaluate their ‘interruptibility’. The time a worker spent in leave-me-alone state varied from individual to individual and day to day, and the percentage ranged from 10 to 51. Generally, the employees wished to work without interruption for roughly 1/3 of the time. Similarly, by studying Microsoft software, Horvitz also came to the discovery that they ordinarily spend over 65 per cent of their day in a low-attention mode.
F
Obviously, today’s phones and computers are probably correct about two-thirds of the time by assuming that their users are always available to answer a call, check an email, or click the ‘OK’ button on an alert box. But for the considerate systems to be functional and useful, their accuracy has to be above 65 in sending when their users are about to reach their cognitive limit.
G
Inspired by Horvitz’s work, Microsoft prototype Bestcom-Enhanced Telephony (Bestcom-ET) digs a bit deeper into every user’s computer to find out clues about what they are dealing with. As I said earlier, Microsoft launched an internal beta test of the system in mid-2003. Horvitz points out that by the end of last October, nearly 3,800 people had been relying on the system to field their incoming calls.
H
Horvitz is, in fact, a tester himself, and as we have our conversation in his office, Bestcom silently takes care of all the calls. Firstly, it checks if the caller is in his address book, the company directory, or the ‘recent call’ list. After triangulating all these resources at the same time, it attempts to figure out what their relationship is. The calls that get through are from family, supervisors and people he called earlier that day. Other callers will get a message on their screens that say he cannot answer now because he is in a meeting, and will not be available until 3pm. The system will scan both Horvitz’s and the caller’s calendar to check if it can reschedule a callback at a time which works for both of them. Some callers will take that option, while others simply leave a voicemail. The same happens with e-mails. When Horvitz is not in his office, Bestcom automatically offers to transfer selected callers to his cellphone, unless his calendar implies that he is in a meeting.
I
Most large companies already use computerized phone systems and standard calendar and contact management software, so tapping into those “sensors” should be straightforward. Not all employees will like the idea of having a microphone on all the time in them, however, nor will everyone want to expose them databook to some program they do not ultimately control. Moreover, some managers might be tempted to equate a “state of low attention” with “goofing off” and punish those who seem insufficiently busy.
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Irish ELK
Toothed cats, mastodons, giant sloths, woolly rhinos, and many other big, shaggy mammals are widely thought to have died out around the end of the last ice age, some 10,500 years ago.
A
The Irish elk is also known as the giant deer (Megaloceros giganteus). Analysis of ancient bones and teeth by scientists based in Britain and Russia have shown the huge herbivore survived until about 5,000 B.C. — more than three millennia later than previously believed. The research team says this suggests additional factors, besides climate change, probably hastened the giant deer’s extinction. The factors could include hunting or habitat destruction by humans.
B
The Irish elk, so-called because its well-preserved remains are often found in lake sediments in Ireland, first appeared about 400,000 years ago in Europe and central Asia. Through a combination of radiocarbon dating of skeletal remains and the mapping of locations where the remains were unearthed, the team shows the Irish elk was scattered across Europe before the last “big freeze.” The deer’s range later contracted to the Ural Mountains, in modern-day Russia, which separate Europe from Asia.
C
The giant deer made its last stand in western Siberia, some 3,000 years after the ice sheets receded, said the study’s co-author, Adrian Lister, professor of palaeobiology at University College London, England. “The eastern foothills of the Urals became very densely forested about 8,000 years ago, which could have pushed them on to the plain,” he said. He added that pollen analysis indicates the region then became very dry in response to further climatic change, leading to the loss of important food plants. “In combination with human pressures, this could have finally snuffed them out,” Lister said.
D
Human hunting has also been put forward as a contributory cause of extinction of the Pleistocene megafauna. The team, though, said their new date for the Irish elk’s extinction hints at an additional human-made problem: habitat destruction. Lister said, “We haven’t got into hunting 7,000 years ago — this was also about the time the first Neolithic people settled in the region. They were farmers who would have cleared the land.” The presence of humans may help explain why the Irish elk was unable to tough out the impact of many climatic fluctuations periods it had survived in the past.
E
Meanwhile, Lister cast doubt on another possible explanation for the deer’s demise — the male’s huge antlers. Some scientists have suggested this exaggerated feature — the result of females preferring to mate with largest-antlered males — possibly became adversely a male’s inconvenience in the mammal’s downfall. They say such wide horns would have become a serious hindrance in the forested regions that spread northward after the last Ice Age. But Lister said, “That’s a hard argument to make, because they had previously survived perfectly well through repeated interglacial [warmer periods between ice ages].” Some research has suggested that a lack of sufficient high-quality forage caused the extinction of the elk. High amounts of calcium and phosphate are required for the annual regrowth of antlers, and therefore large amounts of these minerals are required for the massive structures of the Irish Elk. The males (and males are the antlered) met this requirement partly from their bones, replenishing the frame from food plants after the antlers were grown or reclaiming the nutrients from discarded antlers (as has been observed in extant deer). Thus, in the antler growth phase, Giant Deer were suffering from a condition similar to osteoporosis. When the climate changed at the end of the last glacial period, the vegetation in the animal’s habitat also changed towards species that presumably could not provide sufficient of the required minerals, at least in the western part of its range.
F
The extinction of megafauna around the world was almost completed by the end of the last Ice Age. It is believed that megafaunal vitality was also in response to global climatic changes. Most tropical and subtropical areas exchanged a vast amount of plant life because of radical climatic change. The most dramatic of these changes was the disappearance of the land bridge between North America and Asia about 11,000 years ago. North America joined tropical and sub-tropical Asia. The human exodus from these continents spread fauna and flora across the Americas and was accompanied by climatic change. Australia’s climate changed from cold-dry to warm-dry. As a result, surface water changed. Australia’s lacustrine (inland lakes) became completely dry or dry in the warmer seasons. Most of Australia’s meres dried up. The young animals lost their habitat and had to a narrow band in eastern Australia, where they were able to survive and had better vegetated regions. Some animals may have survived in northeast Australia for up to 60,000 years. Humans arrived in Australia for up to 30,000 years earlier. Certain megafaunal species may have co-existed with humans for at least 30,000 years. Regularly hunted modern kangaroos survived until about 100 years of Aboriginal hunting, but also an onslaught of commercial shooters.
G
The group of scientists led by A.J. Stuart focused on northern Eurasia, which he was taking as Europe, plus Siberia, essentially, where they’ve yet to get the best data that animals became extinct in Europe during the Late Pleistocene. Some cold-adapted animals go through into the last part of the cold stage, and then become extinct when the climate warms up. So you’ve actually got two phases of extinction. Now, neither of these is conclusive — these are the Neanderthals here being replaced by modern humans. But there is no obvious coincidence between the arrival of humans or climate changes, so the two causes have to be combined. There’s a climatic change here, so there’s a double effect here. Again, as animals move through the last part of the cold stage, there’s a fundamental change in the climate, reorganization of vegetation, and the combination of the climate and the presence of humans. Therefore a wave of advanced Paleolithic humans — causes the extinction. There’s a profound difference between the North American data and that of Europe, which summarize that the extinctions in northern Eurasia, in Europe, are moderate and staggered, and in North America are quite sudden. And these things relate to the differences in the timing of human arrival. The extinctions follow from human predation, but only at times of fundamental changes in the environment.
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