题目内容
High Stress May Damage Memory
According to a report issued in May 1998，elderly people who have consistently high b1ood levels of cortisol don’t score as well on memory tests as their peels with lower levels of the stress hormone．What’s more． high 1evels of cortisol are also associated with shrinking 0f the hippocampus，a region of the brain that plays a key role in learning and memory．The 6ndings suggest that even cortisol levels in the normal，“healthy” range can actually accelerate brain aging．
The study results “now provide substantial evidence that long—term exposure to adrenal stress hormones may promote hippocampal aging in normal elderly humans，”write Nada Porter and Philip Landfield of the University of Kentucky in Lexington in their editorial．Cortisol is a hormone released in response to stress by the adrenal glands，which sit on top of the kidneys．
Over a 5 to 6一year period，Dr． Sonia Lupien and his colleagues measured 24一hour cortisol levels in 51 healthy volunteers，most of Whom were in their 70s．
Despite wide variation in cortisol levels．the participants could be divided into three Subgroups：those whose cortisol progressively increased over time and was currently high（increasing／high）：those whose cortisol progressively increased over time and was currently moderate（increasing／moderate）；and subjects whose cortisol decreased，but Was currently moderate（decreasing／moderate）．
The researchers tested the volunteers’ memory on six people in the increasing／high category and five people in the decreasing／moderate group．The groups did not differ on tests of immediate memory，but the increasing／high cortisol group had other memory problems compared with those in the decreasing／moderate group．
The researchers also found that the total volume of the hippocampus in those in the increasing／high group was 14％ lower than those in the decreasing／moderate group，although there were no differences in 0ther brain regions．
The results suggest that brain aging Can be accelerated by levels of adrenal hormones that are not generally regarded as pathological and that variation within this normal range is related to variation in the rate of brain aging．”write Porter and Landfield．“This further suggests that chronic stress may accelerate the worsening of hippocampus．”
第 26 题 The part of the brain important for a person’s learning and memory is．
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下列选项中属于公民权利的是（）。
A．discovering B．Visiting C．traveling D．using
They Say Ireland's the Best
Ireland is the best place in the world to live for 2005, according to a life quality ranking that appeared in Britain's Economist magazine last week.
The ambitious attempt to compare happiness levels around the world is based on the principle that wealth is not the only measure of human satisfaction and well-being.
The index of 111 countries uses data on incomes, health, unemployment, climate,political stability, job security, gender equality as well as what the magazine calls "freedom, family and community life".
Despite the bad weather, troubled health service, traffic congestion （拥挤）, gender inequality, and the high cost of living, Ireland scored an impressive 8.33 points out of 10. That put it well ahead of second-place switzerland, which managed 8.07. Zimbabwe,troubled by political insecurity and hunger, is rated the gloomiest （最差的）, picking up only 3.89 points."A lthough rising incomes and increased individual choices are highly valued," the report said, "some of the factors associated with modernization such as the breakdown（崩溃） in traditional institutions and family values in part take away from a positive impact,"
"Ireland wins because it successfully combines the most desirable elements of the new with the preservation of certain warm elements of the old, such as stable family and
community life."The magazine admitted measuring quality of life is not a straightforward thing to do,and that its findings would have their critics.No. 2 on the list is Switzerland. The other nations in the top 10 are Norway,Luxembourg, Sweden, A．ustralia, Iceland, Italy, Denmark and Spain.
The UK is positioned at No. 29, a much lower position chiefly because of the social and family breakdown recorded in official statistics. The US, which has the second highest per capita GDP （人均国内生产总值） after Luxembourg, took the 13th place in the survey.China was in the lower half of the league at 60th.
第 16 题 For 2,005 years, Ireland has been the best place for humans to live in.
A．disease-producingB．health—improvingC．lire—threateningD．error—correcting
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