Comment on "Brain IRS2 signaling coordinates life span and nutrient homeostasis"

Taguchi et al. (Reports, 20 July 2007, p. 369) reported that mice heterozygous for a null mutation in insulin receptor substrate-2 (Irs2) display a 17% increase in median life span. However, using the same mouse model, we find no evidence for life-span extension and suggest that the findings of Taguchi et al. were due to atypical life-span profiles in their study animals.     

Comment on "Statistical independence of escalatory ecological trends in Phanerozoic marine invertebrates"

Madin et al. (Reports, 12 May 2006, p. 897) reported that escalation has not been an important cause of biological change throughout the history of life. However, they evaluated the escalation hypothesis with inappropriate data. First, global-scale data integrate heterogeneous signals that obscure the economic context of life. Second, diversity data cannot yield information about selection and adaptation.     

Comment on "Differential rescue of light- and food-entrainable circadian rhythms"

Fuller et al. (Reports, 23 May 2008, p. 1074) reported that the dorsomedial hypothalamus contains a Bmal1-based oscillator that can drive food-entrained circadian rhythms. We report that mice bearing a null mutation of Bmal1 exhibit normal food-anticipatory circadian rhythms. Lack of food anticipation in Bmal1-/- mice reported by Fuller et al. may reflect morbidity due to weight loss, thus raising questions about their conclusions.     

前汉阴阳五行说探析

阴阳五行说,始于上古,西汉以来长期在思想文化史中占据统治地位。阴阳五行学说构成了传统文化的最一般理论框架,它满足了古人认识自然、社会和人生的社会需求,反映了人们对自然整体图景和规律的综合认识,是先民的宇宙观和方法论的基础。阴阳五行原是两种不同的学说,到了战国时期,逐渐融为一体,用来解释一切自然、社会现象。     

Stable isotopes in benthic foraminifera: seasonal variation in large tropical species

The shells of large benthic foraminifera contain a record of seasonal temperature ranges and life history stages. Marginopora vertebralis and Cyclorbiculina compressa show distinct differences in life history, growth rate history, and life-span, as reflected in stable isotope patterns within their shells.     

死神门边一汪热泪--试析小说《激情王国》的精神意向

因蒙昧意识因素导致个体生命被命运之神抛来掷去，由此颠覆以往那种对田园牧歌的盲目赞美。理性精神的缺乏致使从肉体到灵魂都被吞噬掉，进而发现历史中隐藏的回归路线。鉴于以上原因，作者提出了文化救亡的课题，而且令人惊喜的是，作者那深沉忧患意识的独特视角正是承继了本民族历史的特有文化命脉。     

"学科馆员"与"参考馆员"之比较

从参考馆员制度与学科馆员制度的发展历史入手，从内涵、服务对象与服务内容、服务方式、服务性质、服务模式、角色与职责、素质能力等方面分析比较了参考馆员与学科馆员的异同，提出在当今网络资源庞杂浩繁，现代信息技术日新月异的情况下，建立和完善学科馆员制度，是知识经济时代知识创新的必然要求，也是图书馆服务创新．提高信息服务质量与水平的需要。     

Complex iron smelting and prehistoric culture in Tanzania

Western scientists and students of history have long explaind th iron bloomery process by evidence available from European archeology. Ethnographic, technological, and archeological research into the technological life of the Haya of northwestern Tanzania show that these people and their forebears 1500 to 2000 years ago practiced a highly advanced iron smelting technology based on preheating principles and, as a result, produced carbon steel. This sophisticated technology may have evolved as an adaptation to overexploited forest resources. These discoveries are significant for the history of Africa and the history of metallurgy.     

孵化季节对阿根廷滑柔鱼生长发育的影响

头足类属种具有寿命短、终生一次繁殖产卵的生长发育特性,这些特性往往与仔鱼的孵化季节密切相关且影响世代的繁衍交替。为此,基于日龄判读和孵化月份推算,研究阿根廷滑柔鱼性腺成熟个体大小与孵化月份的效应关系,分析孵化月份对其生长发育的影响。结果显示,阿根廷滑柔鱼性腺成熟雌性个体的胴长为(246.59±40.36) mm,日龄为(293.79±32.68) d,平均生长速率为(0.84±0.11) mm/d;成熟雄性个体的胴长为(222.82±28.60) mm,日龄为(299.24±32.97) d,平均生长速率为(0.75±0.08) mm/d。性腺成熟个体的孵化月份为3—8月。随着孵化月份推移,性腺成熟个体的日龄显著降低,而平均生长速率逐渐增加;性腺成熟个体胴长大小与其平均生长速率密切相关;孵化月份对雌雄个体生长发育的影响效应具有一致性,较早孵化的个体生长速率较慢,而晚孵化的个体生长速率较快。研究表明,阿根廷滑柔鱼的生长发育与孵化季节密切相关,不同孵化月份的个体通过调节生长速率以达到性腺成熟胴长。     

Comment on "Additive genetic breeding values correlate with the load of partially deleterious mutations"

Tomkins et al. (Reports, 14 May 2010, p. 892) reported a strong negative correlation between breeding values and mutational load in cow-pea weevils. Here, I show that this result can be attributed to a statistical artifact. By testing the observed correlation against an incorrect null hypothesis, they find a negative correlation where one does not exist.     

塑造新形势下高校图书馆女馆员的"三性"形象

论述了高校图书馆知识女性在新的形势下应寻找在事业上追求“刚性”、在家庭生活中捕捉“柔性”,并在事业与家庭中以自身发展为基础寻求“弹性”;同时呼吁要努力营造适应新形势下高校图书馆知识女性全面发展中的工作、学习和生活环境。     

Comparing Immature Development and Life History Traits in Two Coexisting Host-Feeding Parasitoids,Diglyphus isaea and Neochrysocharis formosa (Hymenoptera: Eulophidae)

Coexisting natural enemies that share a common host resource in the same guild usually exhibit variation in their life history traits, due to their need to share a similar ecological niche. In this study, we compared the immature development times and adult life history traits of two coexisting, host-feeding parasitoids, Diglyphus isaea Walker and Neochrysocharis formosa Westwood (Hymenoptera: Eulophidae), of which both attack larvae of the same agromyzid leafminers. These two species are both synovigenic, idiobiont parasitoids, whose adults consume host fluids (“host feeding”) and lay anhydropic eggs. Of the two, D. isaea has a larger body but little or no initial egg load, and engages in similar lifetime host-feeding events. However, it achieves higher fecundity, longer adult longevity, and higher host suppression ability than N. formosa, which has a smaller body and higher initial egg load. Although D. isaea engages in similar lifetime host-feeding events with N. formosa, all of its gains in life history traits per host-feeding event of D. isaea were larger than those of N. formosa. The age-specific fecundity and host mortality curves of N. formosa were more skewed in early life than those of D. isaea. In addition, the ovigeny index of N. formosa was negatively correlated to body size. Our results confirmed that two coexisting parasitoids, which share the same host resource, show different immature development patterns and life history traits, suggesting that different resource allocation mode could be a general rule of coexisting species sharing the same habitat or host.     

Rates of molecular evolution are linked to life history in flowering plants

Variable rates of molecular evolution have been documented across the tree of life, but the cause of this observed variation within and among clades remains uncertain. In plants, it has been suggested that life history traits are correlated with the rate of molecular evolution, but previous studies have yielded conflicting results. Exceptionally large phylogenies of five major angiosperm clades demonstrate that rates of molecular evolution are consistently low in trees and shrubs, with relatively long generation times, as compared with related herbaceous plants, which generally have shorter generation times. Herbs show much higher rates of molecular change but also much higher variance in rates. Correlates of life history attributes have long been of interest to biologists, and our results demonstrate how changes in the rate of molecular evolution that are linked to life history traits can affect measurements of the tempo of evolution as well as our ability to identify and conserve biodiversity.     

生活方式、生产结构、生态环境与中国古代社会经济

本文通过对生活方式、生产结构和生态环境的角度,分析中国历史上社会经济与文化发展的进程。文章指出群居的生活方式、多子继承制度、食尽一山则移一山移民的模式、单一的种植业生产结构等,对古代生态环境产生重要的影响,其结果是供养了较多的人口,进而形成了环境依赖型经济,江南地区由于优越的环境,经济发达。文章最后解释了许多由于生活方式、生产结构和生态环境的原因所形成了经济社会现象。     

“互联网+”时代下优化高校图书馆入馆教育模式探讨

入馆教育是大学新生进入大学生活和学习的重要环节,优化的入馆教育模式可以为信息素养教育打下基础和引导阅读,满足其在大学的生活和学习需求。以“互联网+”时代潮流为背景,分析传统入馆教育的内容及宣传模式,以期借助“互联网+”的潮流探讨出顺应时代发展的入馆教育模式。     

生物化学课程教学方法改革对策研究

为提高教学质量和效果,针对目前生物化学教学中存在的问题提出一系列改革对策。在课堂教学中,通过联系生活实际、引入生命科学史、强化理解、引导回忆、以讨论代讲解等教学措施达到激发学生的学习兴趣,降低学习难度,提高教学质量,培养学生综合素质的课堂教学目标。     

1998～2004年《中国农史》的引文分析

《中国农史》作为中国农业历史学会的会刊,一定程度上代表了农史研究的现状。而论文的引文是一篇科学论文结构的重要组成部分,是反映学术动向和理论来源的基本线索。通过对《中国农史》1998-2004年7年间所发表456篇论文附的12931篇引文的文献的数量类型、语种、年代和自引率等指标,运用文献计量学的方法进行统计分析,得出了我国农史文献引文的一般规律,并对存在的问题提出了一些建议。     

热带地区植物内生真菌生物多样性研究进展

植物内生真菌是指在其生活史的一定或全部阶段生活于健康植物体内部的真菌。内生真菌具有重要的生物学和生态学作用。简要介绍了热带地区植物内生真菌研究概况、资源多样性、寄主选择,并对热带内生真菌生物多样性的发展前景作了分析。     

“三农”信息传播研究综述

大众传媒对于农村的生产、生活方式上具有重要的解构和建构功能,它直接影响了农民的日常作息内容。近些年来,不少学者采用定性和定量的方法,对大众传媒的“三农”信息传播做了研究和探讨。通过搜集重点期刊和书籍的相关文献,研究的脉络进行一番疏理,并借此反思其中研究内容、研究方式等的某些不足。     

从生活需求的角度探讨别墅庭院设计

生活需求是设计的本源,中国人有自己的庭院生活理想,而西方的庭院设计几乎贯穿了西方整个园林发展史。高品质的庭院设计应该是立足于生活需求,综合中西庭院实践成果,现代与传统居住理念相结合的、考虑人生理与心理需求的作品。