Uma das maiores revoluções ocorridas nas últimas décadas foi o uso de cabos de fibra óptica para o tráfego de dados (voz, imagem, som, ...) através das redes de telecomunicação.O maior desses cabos, atualmente, é o SeaMewe 3 que sai da Alemanha e chega até a Coreia do Sul, passando por 32 países, num total de 39000 km de comprimento. Considerando a trajetória da luz pela fibra óptica (ver figura) e que o tempo médio de transmissão de dados entre a Alemanha e a Coreia do Sul seja de, aproximadamente, 0,195 s pode-se afirmar que na fibra óptica ocorre o fenômeno da:

Read the text below, from Scientific American (SA), and choose the best option for the questions.

INTERVIEW WITH PAUL NURSE*

This biologist has followed his interests from "fur and feather" to cell cycles and cancer control

Paul Nurse is one of Britain's most distinguished scientists today. ¹His groundbreaking work on the cell cycle in the 1970s and '80s revealed how cells make the decisions to grow and divide, thus laying the foundation for a MOLECULAR UNDERSTANDING OF CANCER. ²This has earned him numerous honors, including the LASKER BASIC MEDICAL RESEARCH AWARD in 1998, and many regard him a prime candidate for the NOBEL PRIZE. Since 1996, Sir Paul, who WAS KNIGHTED last year, has also been director-general of the largest cancer research organization in the U.K., the IMPERIAL CANCER RESEARCH FUND (ICRF).

(was knighted = foi condecorado como cavaleiro)

SA: When did you decide to become a scientist? Was that quite early, or only at university?

PN: Well, I think actually already as a schoolchild. I remember seeing Sputnik 2 when I was in London. As a young child, eight or nine years old, I read about it in the newspaper and went out in our garden and saw Sputnik 2 fly over, I think in 1957 or 1958, and this was truly amazing. And then when I was a little older I became interested in natural history, and I watched birds, and I collected beetles, and was interested in plants and so on. So my main entrée into biology was through natural history. I think that is quite common.

SA: Was it always clear you wanted to become a biologist, not a physicist or an astronomer?

PN: Yes, but originally I was more interested in natural history and ecology, and then I found it so difficult, because the laboratory of this field [pointing to the grass] is too uncontrolled. So as I grew older, as an undergraduate and then as a postgraduate, I really wanted to work more on molecular and cellular things, because you could do controlled experiments so much better.

SA: Who do you consider your most important teacher?

PN: I had a very good teacher of biology at school, who I recently met again actually, a man called Keith Neal. Then I think a very important person was my postdoctoral advisor, when I was in the University of Edinburgh, Professor Murdoch Mitchison, who gave me great freedom as a young investigator and allowed me to work in my own way. I owe him great debt for that. He encouraged me, he spoke to me, but he really made no attempt to control me, a very good situation.

SA: You are mostly famous for your work on the CELL CYCLE, the cell machinery that controls cell division in eukaryotes. Could you explain what your most important discovery was?

PN: I think the most interesting discovery that I made was to identify components of what is now sometimes called the cell cycle engine. All humans are made up of billions of cells, and they grow and divide. The process that brings about the reproduction of cells is called the cell cycle. I have been interested for many years in what controls progression through that cell cycle, what regulates the cell division process.

SA: You have two daughters, is either one planning to be a scientist?

PN: I have two daughters, that is true. One of them is, at the moment, a sports journalist at our local television station in Oxford, and the other is in her final year at Manchester University doing theoretical physics. So I have one who is a scientist and one who isn't.

SA: Did you ever encourage them to become scientists?

PN: No, but I would be quite pleased if one of them did. But I think they should make up their own minds.

SA: I also know you are a pilot. Do you think flying an airplane and heading a research institute have anything in common, or is it very different?

PN: It's very different, and I think that's why I am attracted to it. I am a glider pilot, mainly, and I fly gliders when I can at the weekend. It's really to do something totally different, having to concentrate on totally different sorts of things, like keeping this airplane up, and going in the right direction, and finding the up currents. It's a major relaxation because it is so different from what I do normally.

SA: Do you think you will always work on the cell cycle?

PN: I am still working on the cell cycle, but I also have a new area, which is related to the cell cycle, which is cell morphogenesis, or how a cell obtains its form, its shape. I think this is another very fundamental biological problem, like the cell cycle, which I find very interesting. It has some relevance to cancer also, because when cancer cells metastasize and spread through the body, they have to undergo a variety of cell shape changes to be able to escape from their tissue and to get into other places. But the basic mechanisms that control cell shape are simply not understood.

SA: Have you had any personal experience with cancer in your family or among friends, and did that change your view of cancer research?

PN: Because I am director-general of ICRF, it actually means that I meet now many people that have been affected by cancer. So although in my own family I have not, one of my friends certainly has. He survived, but that was really a tough time, and it was quite an experience for me.

It makes me realize that cancer isn't simply an academic problem, that it is a problem that obviously influences in very important ways people's lives, and I think that changes the way you view the research that goes on in an institute.

SA: Do you think we will see a cure for cancer like our grandparents saw a cure for infectious diseases?

PN: I don't, actually. Cancer, first of all, is many different diseases, many different sites and forms; some people say it is as many as 200 different diseases. There are many different genes that can become defective to give rise to cancer, and they all have different characteristics. So I think the likelihood of having a common treatment for all of these is just not likely. There will be some treatments that will be useful across the board, but I think it would be a mistake to look for "the cure" to cancer. But what I think we can expect to see is steady improvement by applying this new knowledge to treating and preventing the disease.

*Paul Nurse was awarded the 2001 Nobel Prize for Medicine.

Scientific American: Interviews: Paul Nurse: June 26, 2000 

"False friends" are words in a foreign language which are similar in form to words in our mother tongue, but which do not have the same meaning. Which pair of words below (taken from the text) contains ONLY false friends?

(ENEM 2009 SIMULADO)  As condições de saúde e a qualidade de vida de uma população humana estão diretamente relacionadas com a disponibilidade de alimentos e a renda familiar. O gráfico I mostra dados da produção brasileira de arroz, feijão, milho, soja e trigo e do crescimento populacional, no período compreendido entre 1997 e 2003. O gráfico II mostra a distribuição da renda familiar no Brasil, no ano de 2003.

Considere que três debatedores, discutindo as causas da fome no Brasil, chegaram às seguintes conclusões:

Debatedor 1 – O Brasil não produz alimento suficiente para alimentar sua população. Como a renda média do brasileiro é baixa, o País não consegue importar a quantidade necessária de alimentos e isso é a causa principal da fome.

Debatedor 2 – O Brasil produz alimentos em quantidade suficiente para alimentar toda sua população. A causa principal da fome, no Brasil, é a má distribuição de renda.

Debatedor 3 – A exportação da produção agrícola brasileira, a partir da inserção do País no mercado internacional, é a causa majoritária da subnutrição no País.

Considerando que são necessários, em média, 250 kg de alimentos para alimentar uma pessoa durante um ano, os dados dos gráficos I e II, relativos ao ano de 2003, corroboram apenas a tese do(s) debatedor(es)

A partir da análise da imagem, o aparecimento da Dorsal Mesoatlântica está associada ao(à):

Oximoro, ou paradoxismo, é uma figura de retórica em que se combinam palavras de sentido oposto que parecem excluir-se mutuamente, mas que, no contexto, reforçam a expressão.

Dicionário Eletrônico Houaiss da Língua Portuguesa.

Considerando a definição apresentada, o fragmento poético da obra Cantares, de Hilda Hilst, publicada em 2004, em que pode ser encontrada a referida figura de retórica é: