Successiveness discrimination as a two-state, quantal process

The duration of the "psychophysical time quantum" measured through the application of a two-state model of successiveness discrimination is equal in magnitude to the modal zero-crossing interval of the alpha rhythm. The two quantities have similar distributions and they are correlated over individuals.     

大兴安岭森林景观在不同火干扰及人工更新下的演替动态

该文应用LANDIS模拟大兴安岭图强林业局森林景观1987年特大火灾后,在不同的火干扰条件（不模拟火、火烧轮回期为150年和325年）和不同人工更新方式（完全自然更新、种植落叶松和种植樟子松）,3×3种（共9种）模拟方案下300年的动态变化.研究结果表明:火烧轮回期为150年条件下的火烧明显比火烧轮回期为325年方案下的火烧频繁,总的过火面积也多,但前者以轻度火为主,后者以重度火为主.而人工更新下（无论是种植落叶松还是种植樟子松）过火面积要高于自然更新下的过火面积.造林树种的不同对火也有较大的影响,种植樟子松方案下的过火面积相对较大.不同火干扰条件不仅会影响森林主要物种组成面积,而且还会造成其年龄结构的巨大差异.一般而言,火烧轮回期长有利于低耐火性物种,火烧轮回期短有利于高耐火性物种.但如果物种具有很强的种子扩散和定居更新能力,无论该物种的耐火性高还是低,火烧轮回期短则更利于该物种的生存,但幼龄林所占的比重较大.不同的种植更新方案对于森林物种有显著的影响,可以明显地增加所种植的物种在该区所占的比例.      

Fe-Mg interdiffusion in (Mg,Fe)SiO3 Perovskite and lower mantle reequilibration

Fe-Mg interdiffusion coefficients for (Mg,Fe)SiO3 perovskite have been measured at pressures of 22 to 26 gigapascals and temperatures between 1973 and 2273 kelvin. Perovskite Fe-Mg interdiffusion is as slow as Si self-diffusion and is orders of magnitude slower than Fe-Mg diffusion in other mantle minerals. Length scales over which chemical heterogeneities can homogenize, throughout the depth range of the lower mantle, are limited to a few meters even on time scales equivalent to the age of Earth. Heterogeneities can therefore only equilibrate chemically when they are stretched and thinned by intense deformation.     

Optimal time interval for conducting agrotechnical measures

The methodology of constructing the optimal time interval to conduct agrotechnical measures has been suggested on the basis of a distribution function that can be constructed by the experimental data for previous years. Also considered is the opportunity of raising the homogeneity of data and improving the solutions as a result of using a final mixture of distributions. The optimal intervals are found in the framework of minimax approach.     

Evaluation of the soil penetration resistance along a transect to determine the loosening depth

The objective of this study was to evaluate the distribution of soil strength (measured as cone index, CI) along a 600 m transect and to determine the soil loosening depth necessary to eliminate zones with soil strengths exceeding a threshold value down to a depth of 0.6 m. The transect was located at a site in a glacial drift area which was characterised by sandy deposits overlying boulder clay. A tractor-mounted multi-penetrometer array consisting of four hydraulically driven single vertical penetrometers was used to determine CI at 1-m sampling intervals as a measure of penetration resistance. The spatial fluctuation of the CI readings in general and that of repeatedly averaged readings along the transect was examined. Furthermore, the relationships between the penetration resistance of several soil layers and the relationships between the CI of single penetrometers were identified. Averaged CI values over 5-m intervals were used to determine the depth of soil loosening required. By using various data sub-sets based on the averaged data of the four array mounted penetrometers and simulating several different sampling intervals, treatment intervals and threshold values of soil strength, a sampling interval of about 10 m proved to be sufficiently accurate to determine the loosening depth required.Special Issue: Papers from the 5th European Conference on Precision Agriculture (5ECPA), Uppasala, Sweden, 2005.     

Cu^2＋胁迫诱导花鲢血细胞凋亡的研究

以花鲢Aristichthys nobilis（Rich）血细胞为研究对象,选用不同浓度的铜离子（Cu^2＋）进行不同时间的胁迫诱导,通过瑞士姬姆萨染色和AO／EB荧光染色,在光学和荧光显微镜下观察细胞形态变化,并统计凋亡率。结果表明：在Cu^2＋的胁迫作用下。花鲢血细胞呈现细胞变圆、核变圆、核边缘化、形成凋亡小体等凋亡形态特征,且凋亡细胞随着Cu^2＋浓度的增加和作用时间的延长而增加。表明Cu^2＋能诱导花鲢血细胞发生典型的凋亡,而且细胞凋亡率与Cd^2＋的浓度和处理时间成明显的剂量一效应关系。     

Precisely forecasting population dynamics of agricultural pests based on an interval type-2 fuzzy logic system: case study for oriental fruit flies and the tobacco cutworms

Traditional pest control approaches rely mostly on the experience of farmers, which may not be effective due to lack of scientific information regarding the environment where crops grow. Farmers can initiate a more effective integrated pest management program when precise and quantified results of forecasting pest population outbreaks are provided. Previous studies generally utilize long-term data to predict pest populations, but such a prediction approach might not be useful for farmers who grow fruit and vegetables with shorter life cycles. This paper therefore proposes an interval type-2 fuzzy logic system (IT2FLS) with short-term data to forecast the population dynamics of the oriental fruit fly (OFF, Bactrocera dorsalis (Hendel)) and the tobacco cutworm (TC, Spodoptera litura (Fabricius)). Two automatic monitoring systems are used to collect the data of the population dynamics of OFFs and TCs and the environmental parameters in farming areas. A univariate fuzzy time series forecasting model with difference-based intervals (UFTSFM_DI) and a bivariate fuzzy time series forecasting model with difference-based intervals (BFTSFM_DI) are developed, and integrated into the proposed IT2FLS. It is found that the BFTSFM_DI model yields better performances of forecasting OFF and TC populations when the atmospheric temperature data are employed. With the forecasting results, farmers will have a better understanding of the population dynamics of the OFF and TC in farming areas, so they can take proper measures, such as bagging their fruits and spraying pesticides, before pest outbreaks occur.

     

稻纵卷叶螟种群动态的地统计学分析

概述了地统计学在昆虫种群时空动态分析中的基本方法,应用该方法分析了省通州市和安徽省凤阳县稻纵卷叶螟２３个各世代种群时间格局的结构特征和自相关性,并对历年各世代的种群数量进行了模拟估计。结果表明：种群每世代的累计蛾量和高峰日蛾量在一定世代间隔内均存在着自相关性,当世代间隔超过一定距离时表现为相互独立。两地区种群世代间的影响范围和作用程度的大小存在差异。     

Variation in evolutionary patterns across the geographic range of a fossil bivalve

The fossil record is the only direct source of data for studying modes (patterns) and rates of morphological change over long periods of time. Determining modes and rates is important for understanding macroevolutionary processes, but just how modes and rates vary within a taxon, and why, remain largely unaddressed. We examined patterns of morphological change in the shell of the Mesozoic marine bivalve genus Buchia over its geographic and temporal range. Most modes conformed to either random walks or stasis, and both modes and rates showed variability between locations. For example, stasis was more common in deeper marine environments, whereas random walks occurred more often at the highest paleolatitudes studied. These results indicate that the environment can play an important role in shaping patterns of evolution.     

Fast readout of object identity from macaque inferior temporal cortex

Understanding the brain computations leading to object recognition requires quantitative characterization of the information represented in inferior temporal (IT) cortex. We used a biologically plausible, classifier-based readout technique to investigate the neural coding of selectivity and invariance at the IT population level. The activity of small neuronal populations (approximately 100 randomly selected cells) over very short time intervals (as small as 12.5 milliseconds) contained unexpectedly accurate and robust information about both object "identity" and "category." This information generalized over a range of object positions and scales, even for novel objects. Coarse information about position and scale could also be read out from the same population.     

基于三维点云的灌浆后期玉米植株形态变化研究

快速、准确地获取玉米三维数据是玉米形态结构和功能分析研究的基础。然而,玉米单株和群体原位数据获取存在田间气流稳定性差、器官交叉遮挡严重、高温高湿环境不利于仪器连续工作等问题。因此,采用破坏性取样的方法研究玉米植株的形态变化过程,对玉米植株形态结构数据获取方式的确定具有重要意义。利用三维扫描仪对灌浆后期的两个氮肥处理玉米植株进行不同扫描时间的三维点云数据获取,并通过点云数据分析各叶片的形态变化过程。试验结果表明：从田间原位到室内可控环境下,在取样后2 h以内,玉米植株的形态变化最小,与田间原位的形态结构最为接近。上述结果为玉米植株破坏性取样提供理论依据,也为玉米结构功能模型研究提供数据获取技术支持。     

Hydration rate of obsidian

The hydration rates of 12 obsidian samples of different chemical compositions were measured at temperatures from 95 degrees to 245 degrees C. An expression relating hydration rate to temperature was derived for each sample. The SiO(2) content and refractive index are related to the hydration rate, as are the CaO, MgO, and original water contents. With this information it is possible to calculate the hydration rate of a sample from its silica content, refractive index, or chemical index and a knowledge of the effective temperature at which the hydration occurred. The effective hydration temperature can be either measured or approximated from weather records. Rates have been calculated by both methods, and the results show that weather records can give a good approximation to the true EHT, particularly in tropical and subtropical climates. If one determines the EHT by any of the methods suggested, and also measures or knows the rate of hydration of the particular obsidian used, it should be possible to carry out absolute dating to +/- 10 percent of the true age over periods as short as several years and as long as millions of years.     

The nature of the glass transition in a silica-rich oxide melt

The atomic-scale dynamics of the glass-to-liquid transition are, in general, poorly understood in inorganic materials. Here, two-dimensional magic angle spinning nuclear magnetic resonance spectra collected just above the glass transition of K(2)Si(4)O(9) at temperatures as high as 583 degrees C are presented. Rates of exchange for silicon among silicate species, which involves Si-O bond breaking, have been measured and are shown to be closely related in time scale to those defined by viscosity. Thus, even at viscosities as high as 10(10) pascal seconds, local bond breaking (in contrast to the cooperative motion of large clusters) is of major importance in the control of macroscopic flow and diffusion.     

割胶间隔时间对热研7-33-97胶乳生理参数的影响

[目的]研究不同间隔时间割胶,胶树产胶与排胶的生理变化规律。[方法]以剖龄为2年的热研7．33—97胶树为材料,研究在不刺激的情况下采用不同间隔时间割胶其各项生理指标的变化情况。[结果]间隔4d割胶的干胶产量最高,为42．22g;随着割胶间隔时间的延长,胶乳的黄色体破裂指数逐渐下降,胶乳的干胶含量明显增加,总固形物含量也逐渐增加;间隔4d割胶的胶乳蔗糖含量和镁离子含量最高,平均含量分别为4．319、27．60mmaol／L;间隔2d割胶的胶乳无机磷含量最高,达到3．565mmol／L,但与间隔4d的处理差异不显著。间隔4d割胶的干胶产量、镁离子含量、蔗糖含量、干胶含量等都显著高于间隔1～3d的,表现出了高产高糖高干含的良好生理效应;间隔1d则表现出低产低糖低干含的不良生理效应。[结论]在生产上为热研7-33-97优良新品种制定合适的割胶制度提供了理论依据。     

Sparing of the brain in neonatal undernutrition: amino acid transport and incorporation into brain and muscle

Rates of tyrosine and lysine transport and incorporation into protein were measured in control and undernourished weanling rats. Undernutrition was induced by feeding lactating dams a low protein diet (12 percent casein) from birth to day 21. At weaning, body and brain weights of undernourished rats were 50 percent and 88 percent, respectively, of control values. Lysine and tyrosine transport rates into skeletal muscle were reduced by over 75 percent, more than twice the reduction seen in brain. Rates of amino acid incorporation into muscle protein were reduced by approximately 50 percent; the change in rate of incorporation into brain protein was not statistically significant. These data indicate that, in spite of marked retardation of amino acid transport into brain, the brain seems fully capable of maintaining normal rates of protein synthesis.     

Technical note: A wireless telemetric method of monitoring clinical acidosis in dairy cows

Ruminant animals convert forage containing cellulose by bacterial fermentation into nutrients. The health of the bacterial culture in the rumen is essential for the health and productivity of the animal. Over a number of years fistulated animals have been used to study the rumen and its bacterial population. It has been shown that techniques to maintain the pH of the rumen between 7 and 5.5 pH are essential for the health of the dairy cow. The rumen pH has been recorded by using sensors suspended in the rumen at intervals or exceptionally with data recorders. However, fistulation of an animal requires surgery and is only suitable for a few research animals. This paper describes the development of a telemetric bolus that measured and recorded pH continuously. When interrogated by wireless the bolus transmitted the recorded data to an operator standing beside the cow with a receiving station. Boluses were placed in fistulated animals so that a comparison could be made with a laboratory instrument. Data are presented that show a close correlation between the calibrated laboratory instrument and the bolus at time intervals when the instrument was inserted. From this it can be assumed that the bolus accurately records the temporal variation in rumen pH. Data are presented to show the diurnal change in rumen pH over a 6-week period. Methods of increasing the lifetime and accuracy of the bolus are discussed.     

《内蒙古大学学报》(自然科学版)2007-2011年发文时滞分析

对《内蒙古大学学报》(自然科学版)2007年-2011年发表的5卷30期共649篇时滞论文进行了统计分析。结果表明:2007-2011年该学报的期平均发文时滞为230.85天,5卷平均发文时滞分别为268.8天、287.2天、217.7天、202.2天和178.4天,总体呈下降趋势。对主要栏目文章的时滞也进行了分析。说明《内蒙古大学学报》编辑部处理稿件的能力逐步增强,但仍有较大的改进空间,同时提出了缩短发文时滞的对策。     

Voyager planetary radio astronomy at neptune

Detection of very intense short radio bursts from Neptune was possible as early as 30 days before closest approach and at least 22 days after closest approach. The bursts lay at frequencies in the range 100 to 1300 kilohertz, were narrowband and strongly polarized, and presumably originated in southern polar regions ofthe planet. Episodes of smooth emissions in the frequency range from 20 to 865 kilohertz were detected during an interval of at least 10 days around closest approach. The bursts and the smooth emissions can be described in terms of rotation in a period of 16.11 +/- 0.05 hours. The bursts came at regular intervals throughout the encounter, including episodes both before and after closest approach. The smooth emissions showed a half-cycle phase shift between the five episodes before and after closest approach. This experiment detected the foreshock of Neptune's magnetosphere and the impacts of dust at the times of ring-plane crossings and also near the time of closest approach. Finally, there is no evidence for Neptunian electrostatic discharges.     

A conceptual framework for judging the precision agriculture hypothesis with regard to site-specific nitrogen application

In this study we derive a test that aims to show that the economic optimum nitrogen applications in site-specific management zones are different. In addition, a confidence interval is derived for the difference between optima, and here we show that separate confidence intervals for either optimum are not as good as the former for judging the precision agriculture hypothesis. Both the test and the confidence interval for the difference are based on modeling the returns above N fertilizer cost by quadratic functions of the nitrogen rate. The data are from an N-rate trial at a heterogeneous field in Thalhausen, Germany. This trial could barely support the economic benefit of precision agriculture. A statistical proof that high- and low-yielding zones should be discriminated against just failed to meet the standard 5% level. We also discuss what design of nitrogen fertilizer levels should be used for the test and the confidence intervals.     

电脉冲与化学激活联合处理对猪卵母细胞孤雌发育的影响

探讨了猪卵母细胞电激活后间隔不同时间用化学药物处理对猪卵母细胞孤雌发育的影响。结果表明 :1)电激活后间隔 0 ,3,4 ,5和 6h再分别用 6 二甲基氨基嘌呤 ( 6 Dimethylaminopurine ,6 DMAP)、放线菌酮 (cyclohex imide ,CHX)处理 6h ,各组卵裂率、囊胚细胞数差异不显著 (P >0 0 5 ) ,但在 6 DMAP组中对照组囊胚率极显著高于其余各组 (P <0 0 1) ,在CHX组中对照组囊胚率极显著高于间隔 5和 6h组 (P <0 0 1) ,而其余各组之间差异不显著 (P >0 0 5 ) ;2 )电激活后间隔 4h再分别用 6 DMAP ,CHX和细胞松弛素B(CytochalasinB ,CB) + 6 DMAP处理 6h ,各组卵裂率差异不显著 (P >0 0 5 ) ,对照组囊胚率极显著高于其余各组 (P <0 0 1) ,其余各组囊胚率显著性均无差异 (P >0 0 5 )。对照组中无单倍体囊胚 ,二倍体囊胚为 88 2 4 % ,但 6 DMAP ,CHX ,CB + 6 DMAP中产生的囊胚大部分是单倍体 ,且三者之间无显著性差异 (P >0 0 5 )。以上结果说明 ,猪卵母细胞电激活后间隔一段时间再用DMAP和CHX激活 ,激活作用随时间的延长而减弱 ;猪卵母细胞电激活后 4h再用 6 DMAP ,CHX ,CB + 6 DMAP激活 ,产生的囊胚大部分为单倍体 ,该方法适于猪卵母细胞ICSI的激活。