北极圈

A vast treeless plain in the arctic regions between the ice cap and the tree line .

北极圈内的一片辽阔而没有树木的平原，位于冰帽和林木线之间。

Reporting from Santa's Office in the Arctic Circle, this is Aira Verharskari of YLE for CNN World Report.

YLE，艾拉·弗哈斯卡莉从北极圈内的圣诞老人办公室为CNN《世界报道》报道。

Above, the Medusa-like arms of a northern basket star seek a meal of zooplankton beside a polar alcyonarian soft coral in the shallows beneath an ice sheet in the Canadian Arctic.

意译：在加拿大北极圈的一层薄冰之下，一种两极生活的低级腔肠动物软珊瑚类，被那一组令人恐怖的像蛇发女怪的肢体在北极地域寻找软珊瑚做为一顿美餐。

During the postgenomics era the information about genomic sequence and gene functions provides a new foundation for evolutionary biology and ecology As the first whole-genome sequenced plant Arabidopsis thaliana and its wild relatives have played a critical role in understanding the evolution of genomics and speciation Both A halleri and A lyrata are closely related to the model species A thaliana A halleri ssp gemmifera occurs in northeastern China Japan and Taiwan; while its sister A halleri ssp halleri is mainly distributed in Europe Geographical barriers such as Tienshan Mountain Range isolate these intraspecific sisters Likewise A lyrata ssp kamchatica and ssp lyrata occur in East Asia and North America respectively Such distribution patterns seem to be consistent with allopartic speciation The comparison between ancestral and extant polymorphism by multilocus can be informative about the population genetics of speciation In this study we collected and analyzed DNA sequences of 98 genes from four wild relatives of A thaliana A halleri ssp gemmifera A halleri ssp halleri A lyrata ssp kamchatica and A lyrata ssp lyrata The ancestral states of these four species were compared to each other in terms of level of genetic variation However the ancestral species at the time of speciation were substantially more polymorphic than the extant geographical populations The observations are not fully compatible with speciation by strict allopatry At some species pairs parapatric speciation seems more reasonable in speciation of Arabidopsis The 98 gene sequences are also used for the congruence test between gene genealogy and species phylogeny Only 28 genes support the species phylogeny but there are 23 genes supports another major genealogy { lyrata} thaliana Based on the phylogenetic position change of A lyrata ssp kamchatica and Ks value for each species pair suggested the recent directional gene flow between A halleri ssp gemmifera and A lyrata ssp kamchatica

阿拉伯芥是第一个完成基因体定序的开花植物，其基因体资讯提供植物学研究的重要依据；在解析阿拉伯芥属物种的亲缘关系以及种化机制等重要的演化议题时，阿拉伯芥近缘的野生物种自然成了不可或缺的关键；跟阿拉伯芥近缘的物种包括A halleri及A lyrata，其中A halleri ssp gemmifera主要分布於中国东北、日本以及台湾，与近缘的A halleri ssp halleri其分布於欧洲隔著天山及大陆的障蔽，而A lyrata ssp kamchatica主要分布於东北亚及台湾，与分布於北美五大湖的A lyrata ssp lyrata被北极圈所分隔，这样的分布模式暗示异域种化的可能。藉由多基因分析比较祖先物种与现生物种遗传歧异度的相关可提供讯息探讨种化时期的族群遗传结构，本研究针对A halleri ssp gemmifera、A halleri ssp halleri及A lyrata ssp kamchatica、A lyrata ssp lyrata四个物种，两对互为亚种的姊妹群，以阿拉伯芥为外群进行研究，在四个物种完成98个同源基因的分子序列，利用套装软体MCMCcoal来估算祖先物种的遗传变异，亦估算现生物种的核苷酸歧异度，观察到？多物种配对中祖先物种遗传多型性大於现生物种DNA歧异度，显示异域种化模型并无法完全解释阿拉伯芥属物种的种化模式，在某些物种配对间邻域种化模式应比异域种化更为可能；在基因树与物种树的比较，98个基因片段的亲缘模式只有28个是与已知物种树一致的，有23个基因其树状图支持{ lyrata} thaliana的型式，藉由kamchatica位置的变化以及估算各物种配对间的平均同义置换率，推测在A halleri ssp gemmifera与A lyrata ssp kamchatica间具有近代的单方向基因交流。

The part of the Earth's surface between the Arctic Circle and the Tropic of Cancer or between the Antarctic Circle and the Tropic of Capricorn; characterized by temperate climate.

地球上两个地区之一，位于北极圈和北回归线之间或南极圈和南回归线之间；以温和的气候为特征。

The part ''.'of'.'' the Earth's surface between the Arctic Circle and the ''.'Tropic'.''''.'of'.''''.'Cancer'.'' or between the Antarctic Circle and the ''.'Tropic'.''''.

地球上两个地区之一，位于北极圈和北回归线之间或南极圈和南回归线之间；以温和''。

Of or relating to latitudes just south of the Arctic Circle .

属于或关于紧邻北极圈以南的地区。

The Inuit Circumpolar Council, which brings together Inuit representatives from around the Arctic, declared "sovereignty" over the Arctic's natural resources in April this year, in an effort to forestall what they described as "inappropriate" development.

因纽特北极圈理事会聚齐了北极圈附近的因纽特代表，该理事会在今年4月公开宣称了对北极自然资源的"国家主权"，这样做是为了先发制人，阻止被他们称作"不恰当的"发展。

This site offers University links, courses and research opportunities for students in Svalbard, within the Arctic Circle. Courses offered pertain to glaciation, geology, geomorphological surface form and process for undergraduates as well as research opportunities for students at graduate level within an Arctic glaciated environment.

该站点主要介绍了处于北极圈范围内的挪威瓦尔巴特群岛的大学中心，以及该中心的课程、教学和科研活动等，它的课程主要分为：冰川和冰川学、地质学、地貌及地表过程、以及其他一些有关北极圈冰川环境的研究等。

Arctic birds--fulmars, guillemots, kittywakes, and ivory gulls survive on a diet rich in Arctic cod while murres dive down as deep as a hundred meters in search of fish and squid.

北极圈的鸟类-管鼻鹱、海雀、三趾欧和白鸥依赖丰富的北极圈鳕鱼资源生活。而海鸥可以潜入百米深搜寻鱼和鱿鱼。

It is also known as one of the most poisonous naturally occurring substances.

它也被称为一个最自然发生的有毒物质。

The greatest stress is found at the location on the cross section where V is the largest.

最大应力出现在横截面上V为最大的地方。