语言自主性学习理论评述

人本主义心理学认为学习者具有发展潜能的能力和动力，研究者应促进其个性发展和潜能发挥；社会认知学派通过所构建的研究框架确定学习自主性程度，采用五个维度描述自主学习状态，认为自主学习能力习得是将外部学习技能内化为个人能力的过程；信息加工理论指出完整意义上的自主学习过程经历四个阶段，还构建了自主学习内在机制；元认知理论认为循序渐进的发展过程直接影响自主性学习能力的发展。对各理论学派教育哲学理念进行全面梳理，利于研究者借鉴其成果，从而提出本土化之理论。     

鄂尔多斯能源基地能源开发与地质环境互馈效应调控研究

“鄂尔多斯能源基地能源开发与地质环境互馈效应调控研究”课题组历经3年多研究，查明了鄂尔多斯能源基地能源开发过程中存在的问题，以及能源开发与地质环境互馈效应。选择大柳塔矿区和铜川矿区进行深入剖析，并利用德方提供的鲁尔矿区环境治理和矿区成功转型的经验，提出两个矿区能源开发地质环境保护优化方案，     

Forecasting private consumption: survey‐based indicators vs. Google trends

In this study we introduce a new indicator for private consumption based on search query time series provided by Google Trends. The indicator is based on factors extracted from consumption‐related search categories of the Google Trends application Insights for Search. The forecasting performance of the new indicator is assessed relative to the two most common survey‐based indicators: the University of Michigan Consumer Sentiment Index and the Conference Board Consumer Confidence Index. The results show that in almost all conducted in‐sample and out‐of‐sample forecasting experiments the Google indicator outperforms the survey‐based indicators. This suggests that incorporating information from Google Trends may offer significant benefits to forecasters of private consumption. Copyright © 2011 John Wiley & Sons, Ltd.     

巴尔虎人头面部形态特征的年龄变化

为研究巴尔虎人头面部形态特征随年龄增长而变化的规律,按照国际学术界规定方法,在内蒙古呼伦贝尔市新巴尔虎左旗测量了400例(男196例、女204例)巴尔虎成年人38项头面部指标,并计算了12项头面部体质指数,对巴尔虎人头面部形态特征的年龄变化进行了初步分析.结果表明(1)随年龄增长,巴尔虎人蒙古褶率下降,眼裂渐趋水平,鼻孔最大径趋于水平,眼色变浅,上唇皮肤部变高,红唇变薄.(2)巴尔虎人鼻宽、口裂宽、上唇皮肤部高度、容貌耳长、容貌耳宽与年龄呈正相关;眼外角间宽、唇高、红唇厚度、耳上头高与年龄呈负相关;头长、面宽、下颌角间宽、眼内角间宽、鼻长、鼻深、头围、面颊皮褶8项指标与年龄无相关.(3)形态面、头面高、鼻指数与年龄呈正相关,头长高、口指数与年龄呈负相关.说明巴尔虎人多数骨性头面部指标随年龄增长变化不大,而多数软组织指标随年龄增长变化明显.     

Rapid subtropical North Atlantic salinity oscillations across Dansgaard-Oeschger cycles

Geochemical and sedimentological evidence suggest that the rapid climate warming oscillations of the last ice age, the Dansgaard-Oeschger cycles, were coupled to fluctuations in North Atlantic meridional overturning circulation through its regulation of poleward heat flux. The balance between cold meltwater from the north and warm, salty subtropical gyre waters from the south influenced the strength and location of North Atlantic overturning circulation during this period of highly variable climate. Here we investigate how rapid reorganizations of the ocean-atmosphere system across these cycles are linked to salinity changes in the subtropical North Atlantic gyre. We combine Mg/Ca palaeothermometry and oxygen isotope ratio measurements on planktonic foraminifera across four Dansgaard-Oeschger cycles (spanning 45.9-59.2 kyr ago) to generate a seawater salinity proxy record from a subtropical gyre deep-sea sediment core. We show that North Atlantic gyre surface salinities oscillated rapidly between saltier stadial conditions and fresher interstadials, covarying with inferred shifts in the Tropical Atlantic hydrologic cycle and North Atlantic overturning circulation. These salinity oscillations suggest a reduction in precipitation into the North Atlantic and/or reduced export of deep salty thermohaline waters during stadials. We hypothesize that increased stadial salinities preconditioned the North Atlantic Ocean for a rapid return to deep overturning circulation and high-latitude warming by contributing to increased North Atlantic surface-water density on interstadial transitions.     

ClpS is an essential component of the N-end rule pathway in Escherichia coli

The N-end rule states that the half-life of a protein is determined by the nature of its amino-terminal residue. Eukaryotes and prokaryotes use N-terminal destabilizing residues as a signal to target proteins for degradation by the N-end rule pathway. In eukaryotes an E3 ligase, N-recognin, recognizes N-end rule substrates and mediates their ubiquitination and degradation by the proteasome. In Escherichia coli, N-end rule substrates are degraded by the AAA + chaperone ClpA in complex with the ClpP peptidase (ClpAP). Little is known of the molecular mechanism by which N-end rule substrates are initially selected for proteolysis. Here we report that the ClpAP-specific adaptor, ClpS, is essential for degradation of N-end rule substrates by ClpAP in bacteria. ClpS binds directly to N-terminal destabilizing residues through its substrate-binding site distal to the ClpS-ClpA interface, and targets these substrates to ClpAP for degradation. Degradation by the N-end rule pathway is more complex than anticipated and several other features are involved, including a net positive charge near the N terminus and an unstructured region between the N-terminal signal and the folded protein substrate. Through interaction with this signal, ClpS converts the ClpAP machine into a protease with exquisitely defined specificity, ideally suited to regulatory proteolysis.     

A microworld in Triassic amber

Amber provides an effective medium for conservation of soft-bodied microorganisms, but finds older than 135 million years are very rare and have not so far contained any microbial inclusions. Here we describe 220-million-year-old droplets of amber containing bacteria, fungi, algae and protozoans that are assignable to extant genera. These inclusions provide insight into the evolution and palaeoecology of Lower Mesozoic microorganisms: it seems that the basal levels of food webs of terrestrial communities (biocoenoses) have undergone little or no morphological change from the Triassic to the Recent.     

Phospholipids and the origin of cationic gating charges in voltage sensors

Cells communicate with their external environment through physical and chemical processes that take place in the cell-surrounding membrane. The membrane serves as a barrier as well as a special environment in which membrane proteins are able to carry out important processes. Certain membrane proteins have the ability to detect the membrane voltage and regulate ion conduction or enzyme activity. Such voltage-dependent processes rely on the action of protein domains known as voltage sensors, which are embedded inside the cell membrane and contain an excess of positively charged amino acids, which react to an electric field. How does the membrane create an environment suitable for voltage sensors? Here we show under a variety of conditions that the function of a voltage-dependent K+ channel is dependent on the negatively charged phosphodiester of phospholipid molecules. A non-voltage-dependent K+ channel does not exhibit the same dependence. The data lead us to propose that the phospholipid membrane, by providing stabilizing interactions between positively charged voltage-sensor arginine residues and negatively charged lipid phosphodiester groups, provides an appropriate environment for the energetic stability and operation of the voltage-sensing machinery. We suggest that the usage of arginine residues in voltage sensors is an adaptation to the phospholipid composition of cell membranes.     

Winter forest soil respiration controlled by climate and microbial community composition

Most terrestrial carbon sequestration at mid-latitudes in the Northern Hemisphere occurs in seasonal, montane forest ecosystems. Winter respiratory carbon dioxide losses from these ecosystems are high, and over half of the carbon assimilated by photosynthesis in the summer can be lost the following winter. The amount of winter carbon dioxide loss is potentially susceptible to changes in the depth of the snowpack; a shallower snowpack has less insulation potential, causing colder soil temperatures and potentially lower soil respiration rates. Recent climate analyses have shown widespread declines in the winter snowpack of mountain ecosystems in the western USA and Europe that are coupled to positive temperature anomalies. Here we study the effect of changes in snow cover on soil carbon cycling within the context of natural climate variation. We use a six-year record of net ecosystem carbon dioxide exchange in a subalpine forest to show that years with a reduced winter snowpack are accompanied by significantly lower rates of soil respiration. Furthermore, we show that the cause of the high sensitivity of soil respiration rate to changes in snow depth is a unique soil microbial community that exhibits exponential growth and high rates of substrate utilization at the cold temperatures that exist beneath the snow. Our observations suggest that a warmer climate may change soil carbon sequestration rates in forest ecosystems owing to changes in the depth of the insulating snow cover.     

Insulin secretion and (pro)insulin biosynthesis of cultured mice islets after glibenclamide loading in vitro

Isolated islets from C57Bl/6J mice exposed to 10 mmoles/l glucose supplemented with 5 micrograms/ml glibenclamide for 48 h released significantly less insulin in the subsequent short-time incubation than untreated controls (without glibenclamide), whereas insulin biosynthesis was not suppressed by glibenclamide treatment.