Social environmental effects on gene regulation

Social environmental conditions, particularly the experience of social adversity, have long been connected with health and mortality in humans and other social mammals. Efforts to identify the physiological basis for these effects have historically focused on their neurological, endocrinological, and immunological consequences. Recently, this search has been extended to understanding the role of gene regulation in sensing, mediating, and determining susceptibility to social environmental variation. Studies in laboratory rodents, captive primates, and human populations have revealed correlations between social conditions and the regulation of a large number of genes, some of which are likely causal. Gene expression responses to the social environment are, in turn, mediated by a set of underlying regulatory mechanisms, of which epigenetic marks are the best studied to date. Importantly, a number of genes involved in the response to the social environment are also associated with susceptibility to other external stressors, as well as certain diseases. Hence, gene regulatory studies are a promising avenue for understanding, and potentially developing strategies to address, the effects of social adversity on health.     

Failure of ontological excess baggage as a criterion of the ontic approaches to quantum theory

This article presents a discussion of the notion of quantum ontological excess baggage, first proposed by Hardy. It is argued here that this idea does not have the significance suggested in his paper. It is shown that if this concept is properly analyzed, it fails to pose any threat to the ontic approach to quantum theory in general.     

The Moxee City (Washington) mammoth: morphostratigraphic, taphonomic, and taxonomic considerations

A nearly complete, but highly fractured, proboscidean tusk was unearthed during parking lot construction near Moxee City in central Washington in May 2001. Schreger angle analysis revealed that the tusk was from a mammoth. AMS radiocarbon dating of the tusk established that the mammoth died 14,570 14C yr BP. The age, combined with the biogeography of proboscidean finds in the Pacific Northwest, suggests the tusk is from a Columbian mammoth ( Mammuthus columbi ). The condition of the tusk and its association with basalt and crystalline erratics suggest that a locally derived tusk was swept up in the advancing flood and transported to ～320 m elevation, where it was deposited in the sediments of the 3rd of 3 Missoula Floods that are preserved in the area. The tusk's weathering indicates subaerial exposure prior to burial in the slackwater sediments. Slackwater deposits at the site are pale, ～30-100 cm thick, calcareous, fine-textured strata that include occasional coarse basalt and crystalline sand and gravel. They are intruded by numerous clastic dikes. The sediments encapsulating the tusk lack rhythmites because of their deposition in the nearshore zone of an ephemeral slackwater lake. The first 2 floods inundated the site between 15,300 14 C yr BP and 14,570 14 C yr BP, stripping the A horizon from a well-developed soil formed in alluvial fan sediments sitting above an Ellensburg Formation pediment. The last flood to reach the site occurred later than 14,570 14 C yr BP, as indicated by the presence of the dated tusk. Post-flood and post-MSH S tephra loess derived from the Yakima River floodplain mantles these slackwater deposits. The Warden soil is forming in the now-stable loess parent material.     

Redband trout response to hypoxia in a natural environment

Redband trout ( Oncorhynchus mykiss gairdneri ) were observed approximately every 2 weeks in an intermittent southwest Idaho stream between August and December 1991. Instantaneous daytime dissolved oxygen concentration and water temperature declined from 4.0 to Rhinichthys osculus ) were also present in each pool until drying. The response of these fish to such extreme habitat conditions is probably a primary factor accounting for their distribution within arid landscapes.     

Strict evolutionary conservation followed rapid gene loss on human and rhesus Y chromosomes

The human X and Y chromosomes evolved from an ordinary pair of autosomes during the past 200-300 million years. The human MSY (male-specific region of Y chromosome) retains only three percent of the ancestral autosomes' genes owing to genetic decay. This evolutionary decay was driven by a series of five 'stratification' events. Each event suppressed X-Y crossing over within a chromosome segment or 'stratum', incorporated that segment into the MSY and subjected its genes to the erosive forces that attend the absence of crossing over. The last of these events occurred 30 million years ago, 5 million years before the human and Old World monkey lineages diverged. Although speculation abounds regarding ongoing decay and looming extinction of the human Y chromosome, remarkably little is known about how many MSY genes were lost in the human lineage in the 25 million years that have followed its separation from the Old World monkey lineage. To investigate this question, we sequenced the MSY of the rhesus macaque, an Old World monkey, and compared it to the human MSY. We discovered that during the last 25 million years MSY gene loss in the human lineage was limited to the youngest stratum (stratum 5), which comprises three percent of the human MSY. In the older strata, which collectively comprise the bulk of the human MSY, gene loss evidently ceased more than 25 million years ago. Likewise, the rhesus MSY has not lost any older genes (from strata 1-4) during the past 25 million years, despite its major structural differences to the human MSY. The rhesus MSY is simpler, with few amplified gene families or palindromes that might enable intrachromosomal recombination and repair. We present an empirical reconstruction of human MSY evolution in which each stratum transitioned from rapid, exponential loss of ancestral genes to strict conservation through purifying selection.     

A Cenozoic record of the equatorial Pacific carbonate compensation depth

Atmospheric carbon dioxide concentrations and climate are regulated on geological timescales by the balance between carbon input from volcanic and metamorphic outgassing and its removal by weathering feedbacks; these feedbacks involve the erosion of silicate rocks and organic-carbon-bearing rocks. The integrated effect of these processes is reflected in the calcium carbonate compensation depth, which is the oceanic depth at which calcium carbonate is dissolved. Here we present a carbonate accumulation record that covers the past 53 million years from a depth transect in the equatorial Pacific Ocean. The carbonate compensation depth tracks long-term ocean cooling, deepening from 3.0-3.5?kilometres during the early Cenozoic (approximately 55?million years ago) to 4.6 kilometres at present, consistent with an overall Cenozoic increase in weathering. We find large superimposed fluctuations in carbonate compensation depth during the middle and late Eocene. Using Earth system models, we identify changes in weathering and the mode of organic-carbon delivery as two key processes to explain these large-scale Eocene fluctuations of the carbonate compensation depth.     

网路辅助教学之教学支援服务 :以逢甲大学图书馆资讯素养强化工程为例

新的教育科技为许多大专校院带来更多元、更具弹性的教育劳务提供方式 .将学习的空间由教室局促的场景 ,扩展到超越时空限制的学习型态 ;由传统教师面对学生单向的传输 ,转换成为多面向、多感官的教学情境 ;学习的过程也由重视个人的理解、领悟 ,转变为强调协同学习 (collabo rativelearning)的相互酝酿与启发 ,本文由文献探讨了解教学活动设计各阶段目标任务、探讨教学方法于网路辅助教学应用模式 ,以及课程评量策略 ,并以逢甲大学图书馆协助校内教师进行网路辅助教学之经验为验证 ,依据教师教学历程三阶段 :课程开始前———课程需求分析阶段、课程进行中———学科馆员与教师之协同教学模式、课程结束———教学评量阶段 ,说明图书馆推动网路辅助教学在人力、资源上所投入支援服务以及其运作模式 ,以期能检讨过程并发现问题 ,作为未来发展出合适之教学支援服务 (facultysupport)模式之参考     

关于科技英语翻译中的择义、分析和推敲

为了提高学生的翻译能力,本文收集了有关翻译中如何正确择义、分析和推敲的一些实例,并在理论上详加阐述.