Questões de Concurso

Is Windows 7 Worth It?
Harry McCracken, PC World
Monday, October 19, 2009 10:00 AM PDT

    Reading about a new operating system can tell you only so much about it: After all, Windows Vista had far more features than XP, [CONJUNCTION] fell far short of it in the eyes of many users. To judge an OS accurately, you have to live with it. Over the past ten months, I've spent a substantial percentage of my computing life in Windows 7, starting with a preliminary version and culminating in recent weeks with the final Release to Manufacturing edition. I've run it on systems ranging from an underpowered Asus EeePC 1000HE netbook to a potent HP TouchSmart all-in-one. And I've used it to do real work, not lab routines. Usually, I've run the OS in multiboot configurations with Windows Vista and/or XP, so I've had a choice each time I turned the computer on: [MODAL] I opt for Windows 7 or an older version of the OS? The call has been easy to make, because Win 7 is so pleasant to use.
    So why wouldn't you want to run this operating system? Concern over its performance is one logical reason, especially since early versions of Windows Vista managed to turn PCs that ran XP with ease into lethargic underperformers. The PC World Test Center's speed benchmarks on five test PCs showed Windows 7 to be faster than Vista, but only by a little; I've found it to be reasonably quick on every computer I've used it on - even the Asus netbook, once I upgraded it to 2GB of RAM. (Our lab tried Win 7 on a Lenovo S10 netbook with 1GB of RAM and found it to be a shade slower than XP; for details see "Windows 7 Performance Tests.").
    Here's a rule of thumb that errs on the side of caution: If your PC's specs qualify it to run Vista, get Windows 7; if they don't, avoid it. Microsoft's official hardware configuration requirements for Windows 7 are nearly identical to those it recommends for Windows Vista: a 1-GHz CPU, 1GB of RAM, 16GB of free disk space, and a DirectX 9-compatible graphics device with a WDDM 1.0 or higher driver. That's for the 32-bit version of Windows 7; the 64-bit version of the OS requires a 64-bit CPU, 2GB of RAM, and 20GB of disk space.
    Fear of incompatible hardware and software is another understandable reason to be wary of Windows 7. One unfortunate law of operating-system upgrades - which applies equally to Macs and to Windows PCs - is that they will break some systems and applications, especially at first.
    Under the hood, Windows 7 isn't radically different from Vista. That's a plus, since it should greatly reduce the volume of difficulties relating to drivers and apps compared to Vista's bumpy rollout. I have performed a half-dozen Windows 7 upgrades, and most of them went off without a hitch. The gnarliest problem arose when I had to track down a graphics driver for Dell's XPS M1330 laptop on my own - Windows 7 installed a generic VGA driver that couldn't run the Aero user interface, and as a result failed to support new Windows 7 features such as thumbnail views in the Taskbar.
    The best way to reduce your odds of running into a showstopping problem with Windows 7 is to bide your time. When the new operating system arrives on October 22, sit back and let the earliest adopters discover the worst snafus. Within a few weeks, Microsoft and other software and hardware companies will have fixed most of them, and your chances of a happy migration to Win 7 will be much higher. If you want to be really conservative, hold off on moving to Win 7 until you're ready to buy a PC that's designed to run it well.
    Waiting a bit before making the leap makes sense; waiting forever does not. Microsoft took far too long to come up with a satisfactory replacement for Windows XP. But whether you choose to install Windows 7 on your current systems or get it on the next new PC you buy, you'll find that it's the unassuming, thoroughly practical upgrade you've been waiting for - flaws and all.

(Adapted from http://www.pcworld.com/article/172602/windows_7_revi...)

Skin deep

    Dermatologists are good at spotting unusual bits of skin that might or might not be cancers. Testing whether they actually are, though, is quite literally a bloody pain. For a piece of skin to be identified as malignant or benign, it must be cut out and sent to a laboratory for examination under a microscope. But a team of researchers led by Rainer Leitgeb, a physicist at the Medical University of Vienna, hope to change that. As they describe in Biomedical Optics Express, Dr Leitgeb and his colleagues are exploring a technique called optical coherence tomography (OCT), which they think will allow skin cancer to be diagnosed in situ.
    OCT works by sending infra-red light into tissues and analysing what bounces back. The behaviour of the reflected rays provides information on the structures that they collided with. That, Dr Leitgeb hoped, could be used to generate a map of features just beneath the surface of the skin. Dr Leitgeb and his colleagues set up an experiment that let them test the system on a range of skin conditions, including a healthy human palm, allergy-induced eczema on the forearm, inflammation of the forehead, and two previously diagnosed cases of basal-cell carcinoma. They expected to see normal blood vessels in the healthy palm, increased perfusion caused by dilated and altered vessels in the eczema and the inflammation, and a chaotic jumble of vessels feeding the cancers.
    And that is exactly what they saw. Moreover, the images of the vessels supplying blood to the tumours were good enough to allow them to calculate blood-flow rates. That could also help treatment by allowing doctors to identify the times during their development when tumours are most vulnerable to starvation by having their blood supply cut off.

Internet: <www.economist.com> (adapted).

Based on the text above, judge the items from 16 to 20.