3月13号惨败，在职备考人4月27二战，学习的道路，没有捷径

evamimi

今天的翻译：

American Native Origin的研究

Transportation to the New World is a big topic for debate. 提出问题If the early Americans did cruise巡航 around the continent in canoes and kayaks, might the first settlers have arrived by boat as well? For decades the archaeological community rejected this notion (Ice Agehunters could never have carried all their weapons and left over mammoth meat in such tiny boats!), but in recent years the idea has gathered more support.旧观点反对经由海路假说
One reason for the shift: the nagging困扰的 problem of just how fast people can make the journey from Alaska toTierra del Fuego. 旧观点的问题症结点Consider Dillehay's 14,700-year-old Monte Verde site. According to the previously accepted timeline, people could have made the journey from Asia on foot no earlier than 15,700 years ago(before this time, the ice sheets extending from the North Pole covered Alaskaand Canada completely, making a land passage impossible). If this entry date is correct, the Monte Verde find would indicate that the first settlers had to make the 12,000 -mile trip through two continents in only 1,000 years. In archaeological time, that's as fast as Marion Jones(地球上跑得最快的女人). 提出反对旧观点的理由:行走速度太快? One way to achieve this pace , however,would be by traveling along the Pacific coastlines of North and SouthAmerica in boats. 转折, F提出海路假说新观点Knut Fladmark, a professor of archaeology at Simon Fraser University in Burnaby, BC, first suggested this possibility in the 1970s and remains an advocate of a coastal entry into the Americas. If people had a reason to keep moving, he says, they could have traversed both continents in 100 years. 支持理由:速度符合Fladmark estimates that traveling at a rate of 200 miles a month would have been quite reasonable; the settlers no doubt stopped during winter months and probably stayed in some spots for a generation or so if the local resourceswere particularly tempting. Fladmark's theory, though enticing won't be easy to prove. 让步,提出缺陷Rising sea levels from the melting Ice Age glaciers in undated thousands of square miles along the Pacific coasts of both continents. Any early sites near the ocean that were inhabited before 13,000 years ago would now be deep underwater. 新观点的弱点Recently a few enterprising researchers have attempted to dredge挖出 up artifacts from below the Pacific. In 1997, for example, Daryl Fedje, an archaeologist with Parks Canada (which runs that country's national parks system), led a team that pulled up a small stone tool from 160 feet underwater just off the coast of British Columbia. 提出证据证明新观点The single tool, which Fedje estimates to be around 10,200 years old, does establish that people once lived on the now submerged land but reveals little about the culture there. Excavating underwater sites might turn out to be the only way to prove when humans first arrived on this continent.提出对证据的质疑? And for many researchers this is still a very open question 因为证据力不足，海路说尚未定论, with answers ranging from 15,000 years ago to as far back as 50,000 years ago. When Fladmark first proposed the idea of a coastal migration, the entry date of 14,000 or 15,000 years ago was orthodoxy.公认的,持普遍赞同的
结论是有关F的新观点的开始时间点(14,000~15,000年前)是被普遍接受的

到新大陆的交通是个很大的争议题目。如果早期的米国人确实坐着独木舟和皮划艇巡游大陆，那第一个到落脚的人是坐着船到的咩？很多年以来考古学界不同意这个观点（因为冰河期间的猎人绝对不可能用那么小的船带着他们所有的武器而丢掉猛犸肉的），但是近年来貌似这个理论得到了更多的支持。

转变的理由1：令人困惑的问题就是人需要多快才能完成从阿拉斯加到火地岛这个旅程？考虑下D的14700年MV site(完全没看懂这句话)。根据之前普遍接受的时间线来看，人从亚洲步行开始旅程不可能早于15700年前（早于这个时间，冰海正在从北极点开始覆盖阿拉斯加和加拿大，这让陆地穿行变得不可能）。如果这个时间点是正确的，MV发现就意味着第一个到达米国的人在1000年中一共走了12000miles穿过两个大陆。在考古学时间中，这速度跟地球上跑的最快的女人一样了。然而又一个能达到这速度的办法，就是坐船穿越南北美洲在太平洋海岸线。KF，一个某大学的考古学家，在 1970年第一个推论出这个可能性，而且持续拥护海陆进入米国的观点。如果人们又一个持续行动的理由，他说，他们可以在100年内穿越俩大陆。F估计旅行速度在200m一个月是十分合理的。移居者在冬天是毫无疑问停下，而且还可能停在某个地方修养生息，亦或者本地的资源很吸引人。F的理论，虽然很诱人但是不容易被证明。

来自冰河世纪冰川溶解而导致上升的海平面让两个大陆的海岸线都上升？？？早期在13000年前居住在海岸附近的地方现在都沉入海底了。

最近有些研究者试图太平洋海底挖出 人造物。例如在1997年DF，一个考古学家,跟着PC 带着小队从BC海湾水面下160feet的地方挖起小的石器。F认为这石器大概有10200年的历史，这证明了人曾经住在如今沉下去的地方，但是却没有揭示任何相关的文化。挖掘水下的东西看样子是证明人类曾经到达这个大陆唯一的办法，但是这对于许多研究人员来说仍然是个从问题（从15000奶奶前到50000年前）当F第一次持海陆移民观点的时候，这时间14000-15000年的这个时间是被认可的

evamimi

这个整体跟考古问比较像，文章大体走向就是：

陆路穿越-不可能-海陆穿越-有部分证据但不足
结论，只有时间点确定

CCcarol

感谢楼楼的分享噢~加油加油~~~

prince_cc

楼主，我也在职复习。我觉得verbal最关键的还是单词量。所以劝你花一个月时间好好增加单词量，最好把gre的单词背完。cd里各位牛主的方法是建立在词汇量足够大的基础上辅以时日的练习才能有效果的。

evamimi

楼主，我也在职复习。我觉得verbal最关键的还是单词量。所以劝你花一个月时间好好增加单词量，最好把gre的单词背完。cd里各位牛主的方法是建立在词汇量足够大的基础上辅以时日的练习才能有效果的。

-- by 会员 prince_cc (2012/4/14 16:50:59)

恩恩我就是这样做的，相当同意单词就是王的道理
我从3月到现在就是每天单词，不过我背的是张宏岩那本词以类记
gre的词太恐怖了，lz脑容量严重不够T T

evamimi

2012年04月16日

我发现我更贴速度明显没有一战那么快鸟~
除了上班正值忙季外，没什么可说的是主要的原因
辛苦？大家都一样
进度？冲这个东西不如将题目精品化有效果
正确率？模考成绩就是浮云~虽然经过workshop的洗脑，正确率已经初见成效
不过你们懂得，模考好，so what~
于是我仍旧日复一日背一战不太重视的单词，日复一日做那些其实已经做过的题目，安定自己浮躁的心情。使得每次做题，都全身心投入。
相信自己的水平和智商，稳步前进

今天过来主要是看到了一枚被ross录取的mm，年龄嘛跟我一样
同样工作5年，不满足自己20w的年薪，然后又是一个励志故事
于是乎我觉得，同样工作5年，同样金融业，我拿着远小于20w的工资
木有任何值得夸耀的背景，出去读书也得贷款，在帝都买房就连想都不想
我有什么其它理由骄傲呢，满足呢~
每个平凡人的成功，都是一部催人泪下的励志史

evamimi

2012年04月18日

lz上班忙成狗，下班回家的进度就是各种数学狗和prep套题式做法，粗略计时
发现阅读狗又出了几篇英文，先放上来，等待翻译之

evamimi

画的鉴定

In recent decades, art scholars, restorers and forensic specialists have relied increasingly on scientific techniques to determine the chemical composition of a work’s pigments to try to ascertain when, where and by whom it was likely made. One ostensibly ancient Virgin with Child painting was revealed to be a 1920s fake after testing revealed that it contained Prussian Blue, a pigment that was invented in the 1700s long after the painting would have been made if it were original. Chemical processing of paint samples can provide useful molecular profiles, but it also means physically damaging a chip. Other methods using x-ray fluorescence, scanning electron microscopy and infrared spectroscopy have helped scholars and technicians peer into ancient paint, but they can be time- and labor-intensive. A new study shows how sound waves can detect a dozen different inorganic pigments using Fourier-transform photoacoustic infrared (PAIR) spectroscopy (which makes use of signal processing functions developed by French physicist Joseph Fourier). The process is based in part on an 1880 discovery by Alexander Graham Bell, who demonstrated that shining a modulated beam of light onto an object could create a subtle acoustic wave. "The behavior of paints, pigments, glazes, etc. depends critically on the conditions associated with their production, storage and long-term display," the researchers noted in their paper. "Without a full comprehension of the reactivity of the chemicals involved, the attempted preservation of artworks can sometimes lead to more damage than would occur by just simply leaving the works untreated." The researchers proposed that these simple readings could be included in a database for quick reference in the future. "Once such a database has been established, the technique may become routine in the arsenal of art forensic laboratories," Ian Butler, a chemistry professor at McGill University and coauthor of the new study, said in a prepared statement。

忘了不知道谁说这篇文章很像原文，翻译放上来：

最近，艺术学者，收藏家和法医专家越来越依赖科学技术来鉴定画作颜料的化学成分，以便于来确定画作的时间地点和作者。一副表面上是古代维京人和小孩的画作经过鉴定，被发现是1920年代的复制品，因为这颜料中含PB，一种1700年代发明的颜料，比画作本该的年代晚很多。对于画的一小片样本的化学分析过程可以提供有用的分子结构，但是也会物理上伤害这个片。其他用x光分析，扫描微观电子和红外光谱的办法可以帮助学者和技术人员观察古代画作，但是会相当耗时和费人力~



一种新的
一种新的研究显示声波用PAIR方法可以探测到不同颜料的结构。这过程基于1880年被AGB发明的方法，他阐述说某种模式化的光束照在物体上会产生微量的声波。“画作的特性表现，例如颜料，釉彩等非常依赖它们的生产（这里应该是创作）的条件，保存的条件以及长时间的展示。”这个研究人员在研究里提到“如果没有对涉及到的化学物质有个全面的理解，保存艺术作品就有可能导致比放在那里不处理更严重的损坏。”这个研究者说这些简单的读取可以被包括在数据库里作为以后的参考。“一旦这种数据库建立了，这种技术可以经常性在艺术实验室使用。”IB，一个MU的化学专家以及新研究的合作作者，这样说道。


如果原文内容跟这个文章一样，那么JJ只有v1靠谱，v2绝对有错误

evamimi

树木密度第二部分

实验一
（实验组：spring时期播种a patchy distribution of bluegrass + a random distribution of 四分之一bluegrass数量的groundsel; ）
（控制组：spring时期播种a random distribution of bluegrass+ a random distribution of 四分之一bluegrass数量的groundsel;）
These results did not arise from neighborhood competition. Regardless of the distribution of the bluegrass, the spring generation of groundsel produced essentially the same number of seeds. That is, competition within the spring generation did not generate the differences that appeared in the fall. Pacala and Silander obtained similar results when exploring how patchiness affected the growth rates in a competitive system of velvetleaf and pigweed.
（实验一结果：fall时期发现实验组的groundsel数量超出控制组4倍多.However, 这些结果不能证明理论1，因为spring时期实验组和控制组的groundsel数量差不多）
On the other hand, gaps did affect the groundsel’s growth. In the plots, a large fraction of all the surviving groundsel seedlings grew in areas of low bluegrass density. So patchy plots promoted the growth of groundsel populations by providing a greater number of gaps.
（相反，理论2在发挥作用，大部分fall时期发芽的groundsel是在bluegrass密度较低的地区）
The difference in groundsel’s success in the spring and fall generations suggested that the bluegrass litterdead blades and roots from previous generations—could be a factor. To test that hypothesis, I repeated the above experiment with the patchy and randomly distributed bluegrass but removed the dead bluegrass from half of the plots and left the bluegrass litter intact in the other half. If litter drives the effect of spatial patterning on groundsel, then removing the litter should remove the effect, which is exactly what I found. With the litter intact, groundsel grew better where the bluegrass distribution was patchy; but with the litter removed, the groundsel grew about the same regardless of the distribution of bluegrass. This experiment indicated clearly that competition between generations, not within them, governs the dynamics of the groundsel-bluegrass system and explains the importance of the spatial pattern.
（spring时期的bluegrass的残留叶子和根茎可能是一个重要因素——引出实验二）
（实验组/控制组：在一半的试验种植地中，remove掉bluegrass的残留物，在另一半中，保持残留物完好无损；其他条件与实验一相同）
（实验逻辑：如果隔代植物的残留物是影响spatial patterning的因素的话，那么remove掉残留物应该使这种效果消失，而此次实验确实证实了）
（实验结果：在残留物完好的土地中，groundsel在patchy的分布下比在random的分布下长的更好；在残留物去除的土地中，groundsel在2种分布下长的差不多；证明理论2，而非理论1，的重要性）
A series of greenhouse experiments revealed that the effect of bluegrass litter comes from the dead blades above ground. The presence of grass roots or chemicals that might have leached from the bluegrass did not affect the germination or survival of groundsel seedlings. Instead, litter inhibits groundsel seedlings, because emerging seedlings get trapped by the litter above them. The seedlings cannot penetrate the litter, which prevents them from capturing light or growing, and they die. This structural inhibition between bluegrass litter and groundsel seedlings provides the crucial competitive interaction. In addition, litter generates little trouble for the relatively slender morphology of a bluegrass seedling.
These investigations illustrate that the spatial pattern of bluegrass produces large effects on the success of the competitively inferior groundsel, and that the mechanism involves gap colonization, or interactions between generations. That conclusion has several additional implications. First, the interaction between groundsel and bluegrass includes a time lag-earlier generations affecting later ones. A variety of simple mathematical models illustrate that biological systems with time lags tend to have relatively more complex dynamics than systems without time lags. The second implication involves succession. As succession proceeds, a system’s litter accumulates, which can shift the competitive balance from litter-intolerant species to litter-tolerant ones. In that way, litter can qualitatively alter the outcome of competition. Again, models support such a conclusion, showing that bluegrass should dominate whenever litter accumulates, and that groundsel dominates if the litter decomposes quickly.
Modeling Trade-offs
These small-scale experiments showed that groundsel grows more successfully in a patchy plot. In the simplest terms, one might say that greater amounts of bare ground favor groundsel, because the plant requires such gaps for establishment. Then one might ask: Given a particular amount of bare ground, how does its spatial distribution influence the success of invading weeds? I approached that question in collaboration with Jonathan Newman of Southern Illinois University and Ernesto Floresroux, then of the University of Chicago. We performed experiments on a somewhat larger spatial scale-over a few meters-where we tried to determine how the dispersion of gaps influences how fast groundsel progresses through a field. These experiments reveal the community-level repercussions of between-generation competition.
We approached the effects of gap dispersion with a simple experiment. For each experimental plot in a field of ryegrass, we created six transects that were oriented like spokes on a wheel. On each transect, we created artificial gaps that covered one of three areas: 25, 225 or 900 square centimeters. To control the total amount of gap in a given transect, we created fewer large gaps than small ones. We distributed the gaps either uniformly or randomly, based on the distance between them. By analogy with the small-scale experiments described earlier, a large variance in the intergap distance corresponds to a patchy distribution, and equal intergap distances correspond to a uniform distribution. We introduced 12 invading groundsel plants in the center and then counted the number and position of all seedlings in two subsequent generations-hoping to determine whether the success of invasion depends on the spatial heterogeneity of the gaps.
One can assess a plant’s success of invasion in two different ways. The number of individuals that get established provides one index, and the distance between a parent and its offspring-the rate of spread-provides another. In our experiments, larger gaps increased the number of established groundsel seedlings, even though we controlled for overall gap area. In addition, the invading groundsel spread faster with large gaps. For example, large gaps produced nearly three times more distance between a parent and its offspring, as compared with small gaps. Moreover, the invading groundsel produced more established seedlings with patchy gaps than uniform ones, regardless of the size of the gaps. However, offspring traveled farther when the gaps were positioned uniformly, regardless of the size of the gaps.
We wondered if the way that a plant’s “shower” of seeds would fall on such gaps would lead to similar results. One can imagine that a plant produces a seed shadow, which depicts the proportion of seeds that fall relative to the distance from the plant. In our transect experiment, some seeds would fall in gaps and germinate, and others would fall in vegetation and not germinate. By knowing a plant’s seed shadow and a transect’s arrangement of gaps, one can predict the expected distance between parents and seeds that land in gaps. A simple mathematical model of this scenario produced results that resembled what we found in our experiments. In other words, how the seeds disperse and the strong competitive dominance of established grass over seedlings explains what we observed.
These results point to an interesting trade-off: An invading plant can progress faster in a field that contains a uniform distribution of gaps, but fewer seeds land successfully in uniform gaps. This trade off affects models of the persistence of competitively inferior species in patchy environments. In the past, such models suggested that a competitively inferior species can persist in a community by dispersing more effectively than its superior competitor, but models of that phenomenon ignore the spatial positioning of gaps. Our results, however, indicate that a competitively inferior species faces a more difficult challenge, because of the negative relationship between rates of dispersal and the probability that seeds land in gaps and establish successfully Dispersing seeds that travel a far distance, on average, require uniformly positioned gaps; but patchy gaps lead to more established seedlings. In other words, a plant can either widely disperse its offspring or produce lots of them, but it probably cannot do both. Future research should address how competitively inferior species persist in realistic, spatially heterogeneous environments.
My work with two common weedsgroundsel and bluegrass-shows that competition between these plants depends on many factors. Competition between generations-later groundsel seeds battling established bluegrass-is the primary factor that governs the dynamics of this system. Nevertheless, groundsel’s genotype determines largely when a seedling will emerge-a crucial factor in competitive success-and that suggests that contemporary plants must compete, as well. Moreover, the result of competition between groundsel and bluegrass also depends on the structure of the local environment, including the size and arrangement of gaps. In the future, ecologists hope to develop models and experimental systems that simultaneously examine how these factors contribute to plant competition.