【阅读】01/24起粤督寂静整理（1/29更新，28篇阅读，27篇考古）

修日逸

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billyisfragile!

https://pdfs.semanticscholar.org/2efb/8e47bb3465daf51d57524d64657513ffafd6.pdf

yhy44099097

追更新！

VicyChiu

之前做TN的时候也看到类似飞鸟的，感觉有类似的文章。
Two opposing scenarios, the "arboreal" hypothesis and the "cursorial" hypothesis, have traditionally been put forward concerning the origins of bird flight. The "arboreal" hypothesis holds that bird ancestors began to fly by climbing trees and gliding down from branches with the help of incipient feathers: the height of trees provides a good starting place for launching flight, especially through gliding. As feathers became larger over time, flapping flight evolved and birds finally became fully air-borne. This hypothesis makes intuitive sense, but certain aspects are troubling. Archaeopteryx (the earliest known bird) and its maniraptoran dinosaur cousins have no obviously arboreal adaptations, such as feet fully adapted for perching. Perhaps some of them could climb trees, but no convincing analysis has demonstrated how Archaeopteryx would have both climbed and flown with its forelimbs, and there were no plants taller than a few meters in the environments where Archaeopteryx fossils have been found. Even if the animals could climb trees, this ability is not synonymous with gliding ability. (Many small animals, and even some goats and kangaroos, are capable of climbing trees but are not gliders.) Besides, Archaeopteryx shows no obvious features of gliders, such as a broad membrane connecting forelimbs and hind limbs.

The "cursorial"(running) hypothesis holds that small dinosaurs ran along the ground and stretched out their arms for balance as they leaped into the air after insect prey or, perhaps, to avoid predators. Even rudimentary feathers on forelimbs could have expanded the arm's surface area to enhance lift slightly. Larger feathers could have increased lift incrementally, until sustained flight was gradually achieved. Of course, a leap into the air does not provide the acceleration produced by dropping out of a tree; an animal would have to run quite fast to take off. Still, some small terrestrial animals can achieve high speeds. The cursorial hypothesis is strengthened by the fact that the immediate theropod dinosaur ancestors of birds were terrestrial, and they had the traits needed for high lift off speeds: they were small, agile, lightly built, long-legged, and good runners. And because they were bipedal, their arms were free to evolve flapping flight, which cannot be said for other reptiles of their time."

billyisfragile!

Perhapsnot coincidentally, it is during this Middle to Upper Paleolithic transitionthat humans of modern appearance had begun stakingtheir claim on Europe,which until this point was strictly Neandertal territory. Although the identity of the makers of theearliest Upper Paleolithic artifacts is not known with certainty, because of alack of human remains at the sites, they are traditionally assumed to have beenanatomically modern H. sapiens rather than Neandertals. Some researchers have thus surmised that confrontation between the  twopopulations awakened in the invaders a creative ability that had heretofore lain dormant.

P1，说是195,000年的早期人类化石找到了，但是缺乏mental发展的证据，然后有40，000年前的化石表明人类忽然智力得到飞速发展，会做sophisticated 工具，会画画还是什么的, 里面有个surmise的单词，不认识，但是那句话里有考点。

Mapping Modernity

Humans who looked like us had evolved by 195,000 years ago, as evidenced by Homo sapiens fossils from the site of Omo Kibish in Ethiopia. But received archaeological wisdom holds that humans did not begin behaving like us until nearly 150,000 years later. That notion stems largely from cultural remains uncovered in Europe, where art, ritual, technological advances and other indications of modern thinking flowered spectacularly and suddenly after about 40,000 years ago, around the time that anatomically modern humans started colonizing Europe. Recent finds, including those from Blombos Cave in South Africa, are revealing that many sophisticated practices emerged long before 40,000 years ago at sites outside of Europe, suggesting that humans were our cognitive equals by the time they attained anatomical modernity, if not earlier. Indeed, the fact that at least some Neandertals appear to have thought symbolically raises the possibility that such capacities were present in the last common ancestor of Neandertals and H. sapiens. The map below shows the locations of the sites mentioned in the article.

billyisfragile!

SCIENTIFIC AMERICAN
May 2009
Volume 300, Issue 5

https://www.scientificamerican.com/article/how-planets-lose-their-atmospheres/

Our Planet's Leaky Atmosphere
As Earth's air slowly trickles away into space, will our planet come to look like Venus?
By Kevin J. Zahnle and David C. Catling

Dust in the Wind

Atmospheres rich with hydrogen are the most vulnerable to hydrodynamic escape. As hydrogen flows outward, it can pick up and drag along heavier molecules and atoms with it. Much as the desert wind blows dust across an ocean and sand grains from dune to dune, while leaving cobbles and boulders behind, the hydrogen wind carries off molecules and atoms at a rate that diminishes with their weight. Thus, the present composition of an atmosphere can reveal whether this process has ever occurred.

In fact, astronomers have seen the telltale signs of hydrodynamic escape outside the solar system, on the Jupiter-like planet HD 209458b. Using the Hubble Space Telescope, Alfred Vidal-Madjar of the Paris Astrophysics Institute and his colleagues reported in 2003 that the planet has a puffed-up atmosphere of hydrogen. Subsequent measurements discovered carbon and oxygen in this inflated atmosphere. These atoms are too heavy to escape on their own, so they must have been dragged there by hydrogen. Hydrodynamic loss would also explain why astronomers find no large planets much closer to their stars than HD 209458b is. For planets that orbit within three million kilometers or so of their stars (about half the orbital radius of HD 209458b), hydrodynamic escape strips away the entire atmosphere within a few billion years, leaving behind only a scorched remnant.

P2：地球、金星和火星的XX都差不多，但是如果hydrogen escape不存在的话，他们的某abundance就会和太阳的一样了。但是事实是不一样（这里也有题，也是在选项里出现的）。后面不太记得了……

This evidence for planetary winds lends credence to ideas put forth in the 1980s about hydrodynamic escape from ancient Venus, Earth and Mars. Three clues suggest this process once operated on these worlds. The first concerns noble gases. Were it not for escape, chemically unreactive gases such as neon or argon would remain in an atmosphere indefinitely. The abundances of their different isotopes would be similar to their original values, which in turn are similar to that of the sun, given their common origin in the solar nebula. Yet the abundances differ.

Second, youthful stars are strong sources of ultraviolet light, and our sun was probably no exception. This radiation could have driven hydrodynamic escape.

P3：地球和金星都如何，但是金星更像太阳。由于radiation, 使金星大气里的水分子，导致不能形成雨。后面又忘了……

Third, the early terrestrial planets may have had hydrogen-rich atmospheres. The hydrogen could have come from chemical reactions of water with iron, from nebular gases or from water molecules broken apart by solar ultraviolet radiation. In those primeval days, asteroids and comets hit more frequently, and whenever they smacked into an ocean, they filled the atmosphere with steam. Over thousands of years the steam condensed and rained back onto the surface, but Venus is close enough to the sun that water vapor may have persisted in the atmosphere, where solar radiation could break it down.

Under such conditions, hydrodynamic escape would readily operate. In the 1980s James F. Kasting, now at Pennsylvania State University, showed that hydrodynamic escape on Venus could have carried away an ocean’s worth of hydrogen within a few tens of millions of years [see “How Climate Evolved on the Terrestrial Planets,” by James F. Kasting, Owen B. Toon and James B. Pollack; Scientific American, February 1988]. Kasting and one of us (Zahnle) subsequently showed that escaping hydrogen would have dragged along much of the oxygen but left carbon dioxide behind. Without water to mediate the chemical reactions that turn carbon dioxide into carbonate minerals such as limestone, the carbon dioxide built up in the atmosphere and created the hellish Venus we see today.

Wendyzwd

SylviaYinChuang 发表于 2019-1-24 22:51
這是我今天遇到的三篇 閱讀
並且附上 疑似原文的連結    ( 藍色部分 是考試時 RC 文章出現的 但其他也可以 ...

赞

Wendyzwd

bzy! 发表于 2019-1-25 10:29
This paper estimates the energy footprint required for various phases of bottled water production, t ...

同意！               

Wendyzwd

SylviaYinChuang 发表于 2019-1-24 22:51
這是我今天遇到的三篇 閱讀
並且附上 疑似原文的連結    ( 藍色部分 是考試時 RC 文章出現的 但其他也可以 ...

请大神看看 鸟的进化那篇文章 是这片rc吗:

Although many lines of evidence indicate that birds evolved from ground-dwelling
theropod dinosaurs, some scientists remain unconvinced. They argue that theropods
appeared too late to have given rise to birds, noting that Archaeopteryx lithographica –
the oldest known bird – appears in the fossil record about 150 million years ago, whereas
the fossil remains of various nonavian maniraptor theropods – the closest known relatives
of birds – date only to about 115 million years ago. But investigators have now uncovered
bones that evidently belong to nonavian maniraptors dating to the time of Archaeopteryx.
In any case, failure to findfossils of a predicted kind does not rule out their existence in an
undiscovered deposit. Skeptics also argue that the fused clavicles (the “wishbone”) of birds
differ from the unfused clavicles of theropods. This objection was reasonable when only
early theropod clavicles had been discovered, but fossilized theropod clavicles that look
just like the wishbone of Archaeopteryx have now been unearthed. Finally, some scientists
argue that the complex lungs of birds could not have evolved from theropod lungs, an
assertion that cannot be supported or falsified at the moment, because no fossil lungs are
preserved in the paleontological record.

题目 T-4-Q5The primary purpose of the passage is toA. compare the development of
two hypotheses concerning the evolutionary origin of birdsB. suggest revisions to the
standard theory of the evolutionary history of birdsC. evaluate the usefulness of fossil
evidence in determining the evolutionary history of birdsD. challenge the theory that
birds evolved from ground-dwelling theropod dinosaursE. respond to criticisms of the
theory that birds evolved from ground-dwelling theropod dinosaursT-4-Q6In the context
of the passage, the phrase “fossils of a predicted kind”(line 16) most likely refers to which
of the following? A. Theropod fossils with fused claviclesB. Theropod fossils that are
similar in structure to Archaeopteryx fossilsC. Theropod fossils dating back more than
150 million yearsD. Fossils indicating the structure of theropod lungsE. Fossils
indicating the structure of Archaeopteryx lungsT-4-Q7Which of the following is mentioned
in the passage as an argument made by scientists who are unconvinced that birds evolved
from theropod dinosaurs?A. There are no known theropod dinosaur fossils dating from
a period after the time of Archaeopteryx.B. There are no known theropod dinosaur
fossils that indicate the structure of those dinosaurs’ lungs.C. Theropod dinosaurs
appear in the fossil record about 150 million years ago.D. Theropod dinosaurs did not
have fused clavicles.E. Theropod dinosaurs had certain bones that look just like those
of Archaeopteryx.

billyisfragile!

https://www.economist.com/node/21536539

Ageing
Forever young?
A way to counteract part of the process of growing old
Nov 5th 2011

BIOLOGISTS have made a lot of progress in understanding ageing. They have not, however, been able to do much about slowing it down. Particular versions of certain genes have been shown to prolong life, but that is no help to those who do not have them. A piece of work reported in this week's Nature by Darren Baker of the Mayo Clinic, in Minnesota, though, describes an extraordinary result that points to a way the process might be ameliorated. Dr Baker has shown—in mice, at least—that ageing body cells not only suffer themselves, but also have adverse effects on otherwise healthy cells around them. More significantly, he has shown that if such ageing cells are selectively destroyed, these adverse effects go away.

第二个问题是说，以下哪种行为和实验中的行为（实验就是喂这些mice药，杀死任何产生P16的细胞）延缓衰老的效果是相似的？狗主选的“提高能够产生P16的细胞分裂的upper limit，并且保持不能产生P16的细胞分裂的upper limit不变”，但是不确定。

The story starts with an observation, made a few years ago, that senescent cells often produce a molecule called P16INK4A. Most body cells have an upper limit on the number of times they can divide—and thus multiply in number. P16INK4A is part of the control mechanism that brings cell division to a halt when this limit is reached.

The Hayflick limit, as the upper bound is known (after Leonard Hayflick, the biologist who discovered it), is believed to be an anticancer mechanism. It provides a backstop that prevents a runaway cell line from reproducing indefinitely, and thus becoming a tumour. The limit varies from species to species—in humans, it is about 60 divisions—and its size is correlated with the lifespan of the animal concerned. Hayflick-limited cells thus accumulate as an animal ages, and many biologists believe they are one of the things which control maximum lifespan. Dr Baker's experiment suggests this is correct.

Age shall not weary them

Dr Baker genetically engineered a group of mice that were already quite unusual. They had a condition called progeria, meaning that they aged much more rapidly than normal mice. (A few unfortunate humans suffer from a similar condition.) The extra tweak he added to the DNA of these mice was a way of killing cells that produce P16INK4A. He did this by inserting into the animals' DNA, near the gene for P16INK4A, a second gene that was, because of this proximity, controlled by the same genetic switch. This second gene, activated whenever the gene for P16INK4A was active, produced a protein that was harmless in itself, but which could be made deadly by the presence of a particular drug. Giving a mouse this drug, then, would kill cells which had reached their Hayflick limits while leaving other cells untouched. Dr Baker raised his mice, administered the drug, and watched.

第二段 科学家做基因改造的老鼠实验，3天注射一次杀死分泌P16细胞的药，发现肌肉组织衰老速度变得缓慢了，但是心脏却没有，因为没有分泌P16的细胞。

The results were spectacular. Mice given the drug every three days from birth suffered far less age-related body-wasting than those which were not. They lost less fatty tissue. Their muscles remained plump (and effective, too, according to treadmill tests). And they did not suffer cataracts of the eye. They did, though, continue to experience age-related problems in tissues that do not produce P16INK4A as they get old. In particular, their hearts and blood vessels aged normally (or, rather, what passes for normally in mice with progeria). For that reason, since heart failure is the main cause of death in such mice, their lifespans were not extended.

The drug, Dr Baker found, produced some benefit even if it was administered to a mouse only later in life. Though it could not clear cataracts that had already formed, it partly reversed muscle-wasting and fatty-tissue loss. Such mice were thus healthier than their untreated confrères.

Analysis of tissue from mice killed during the course of the experiment showed that the drug was having its intended effect. Cells producing P16INK4A were killed and cleared away as they appeared. Dr Baker's results therefore support the previously untested hypothesis that not only do cells which are at the Hayflick limit stop working well themselves, they also have malign effects (presumably through chemicals they secrete) on their otherwise healthy neighbours.

Regardless of the biochemical details, the most intriguing thing Dr Baker's result provides is a new way of thinking about how to slow the process of ageing—and one that works with the grain of nature, rather than against it. Existing lines of inquiry into prolonging lifespan are based either on removing the Hayflick limit, which would have all sorts of untoward consequences, or suppressing production of the oxidative chemicals that are believed to cause much of the cellular damage which is bracketed together and labelled as senescence. But these chemicals are a by-product of the metabolic activity that powers the body. If 4 billion years of natural selection have not dealt with them it suggests that suppressing them may have worse consequences than not suppressing them.

By contrast, actually eliminating senescent cells may be a logical extension of the process of shutting them down (they certainly cannot cause cancer if they are dead), and thus may not have adverse consequences. It is not an elixir of life, for eventually the body will run out of cells, as more and more of them reach their Hayflick limits. But it could be a way of providing a healthier and more robust old age than people currently enjoy.

Genetically engineering people in the way that Dr Baker engineered his mice is obviously out of the question for the foreseeable future. But if some other means of clearing cells rich in P16INK4A from the body could be found, it might have the desired effect. The wasting and weakening of the tissues that accompanies senescence would be a thing of the past, and old age could then truly become ripe.