安徽禹会村遗址双墩文化时期农业发展的植硅体证据

本文利用植硅体分析方法,对安徽蚌埠禹会村遗址双墩文化时期44份土壤样品开展植物考古研究,重点关注典型农作物植硅体类型及其形态特征,以及敏感型与固定型植硅体组合特征等。结果显示,禹会村遗址大部分样品中皆发现有水稻特征型植硅体,并未发现粟、黍等旱地作物遗存;水稻扇型及双峰型植硅体形态特征分析显示,水稻遗存为驯化程度较高的粳型稻。以上研究结果表明,该遗址双墩文化时期的农业结构延续了顺山集文化时期以来种植粳型稻为主的传统。此外,通过水稻植硅体高密度样品中敏感型与固定型植硅体含量比值为0.7±0.2推测,该遗址水稻栽培环境属于“高地势-雨水供给”或“低地势-雨水供给”类型。本文研究结果为探讨淮河中游地区新石器时代农业发展、水稻栽培与驯化以及人类适应策略等问题提供了重要科学依据。     

Stomach cancer incidence trends in selected Latin America countries: Age,period, and birth-cohort effects

Backgroundto explore the age, period, and birth-cohort effects on stomach cancer incidence trends during 3 decades in selected Latin American countries.Methodsa time-trend study was performed using Cancer Incidence in Five Continents data from high-quality population-based cancer registries(PBCRs) in Latin American countries. Crude and age-standardized incidence rates(ASRIs) were calculated. Time trends in ASRIs were assessed using the average annual percentage change(AAPC). Age-period-cohort effects were estimated by Poisson regression for individuals aged between 20 and 79 years with stomach cancer informed by PBCRs from 1983 to 2012 in Cali(Colombia); from 1982 to 2011 in Costa Rica; and from 1988 to 2012 for Goiania(Brazil) and Quito(Ecuador). The goodness-of-fit model was tested using the deviance of the models.Resultsa decrease in age-standardized incidence rates was observed for both genders in all populations covered by PBCRs, except for young men from Cali(AAPC 3.89 95 %IC: 1.32–7.29). The age effect was statistically significant in all areas, and the curve slope reached peaks in the older age groups. The cohort effect was observed in all PBCRs. Regarding the period effect, an increased ratio rate was observed for both genders in Costa Rica(1997–2001 women RR 1.11 95 %CI: 1.05–1.17; men RR 1.12 95 %CI: 1.08–1.17) and Goiânia(2003–2007 women RR 1.21 95 %CI: 1.08–1.35; men RR 1.09 95 %CI: 1.01–1.20), while Quito(1998–2002 women RR 0.89 95 %CI: 0.81–0.98; men RR 0.86 95 %CI: 0.79–0.93) presented a decrease.Conclusionthe present study showed a decreasing gastric cancer trend for over the past 30 years with gender and geographic variations. Such a decrease seems to be mainly a result of cohort effects, suggesting that the economic market opening process led to changes in the risk factor exposures over successive generations. These geographic and gender variations may reflect cultural/ethnic/gender differences and differences in dietary and smoking rate patterns. However, an increased incidence was observed for young men in Cali, and additional studies are needed to determine the cause of the increasing incidence in this group.     

Comparative analysis of population characteristics of the brown planthopper,Nilaparvata lugens stål,between wet and dry rice cropping seasons in West Java,Indonesia

Population dynamics of the brown planthopper (BPH),Nilaparvata lugens Stål, were investigated in paddy fields in the coastal lowland of West Java, Indonesia, where rice is cultivated twice a year, in the wet and dry cropping seasons. Distinct differences in the basic features of population dynamics were detected between the two rice cropping seasons: (1) In the wet season, BPH populations multiplied rapidly in the period from initial to peak generation, reaching quite often the destructive level despite the low density of initial immigrants. However, in the dry season, the population growth rate and the peak population density were much lower than those in the wet season. The abundance of natural enemies such as arthropod predators played a major role in determining such a difference in seasonal population development. (2) The density at the peak generation or the occurrence of outbreaks in each field was predictable in the wet season with fairly high accuracy on the basis of the density at the initial or previous seasonal generations. In the dry season, however, the rate of population growth and the peak population density widely varied among the fields depending on the water status in each field. (3) Density-dependent processes to regulate the population density were detected in both cropping seasons. In the wet season, the regulatory processes were only detected in such high densities as cause the considerable deterioration of host plants, which suggested that the processes were largely attributable to intra-specific competition. In the dry season, however, the regulatory processes operated at a much lower density in the earlier stages of the crops. The results of an analysis of adult longevity or residence period suggested that the density-dependent dispersal of macropterous adults played an important role in stabilizing the population fluctuation among the fields in the early dry season.     

抗心律失常药UK－68798对家兔心脏房室结区不同细胞的电生理作用

在离体家兔ＡＶＮ区标本上,用微电极技术研究了Ⅲ类抗心律失常新药ＵＫ－６８７９８对ＡＮ,Ｎ,ＮＨ,Ｈ４种细胞的电生理效应。浓度５×１０－９至５×１０－６ｍｏｌ／Ｌ的ＵＫ－６８７９８对４种细胞的动作电位幅值（ＡＰＡ）、静息膜电位（ＲＰ）皆无影响。对ＡＶＮ的自搏率有剂量依赖性减慢作用,但不改变Ａ－Ｈ传导时间。在５×１０－８－５×１０－６ｍｏｌ／Ｌ剂量范围,此药使动作电位时程（ＡＰＤ５０）和（ＡＰＤ９０）发生剂量依赖性延长。４种细胞中以Ｎ细胞的ＡＰＤ５０和ＡＰＤ９０延长百分率最高。各种细胞ＡＰＤ９０延长百分率的排列次序为Ｎ＜ＡＮ＜Ｈ＜ＮＨ,当浓度为５×１０－６ｍｏｌ／Ｌ时的延长百分率分别为９５±２６％（Ｎ）,７５±２２％（ＡＮ）,６３±２６％（Ｈ）,４６±２６％（ＮＨ）。在ＵＫ－６８７９８的作用下,４种细胞的有效不应期（ＥＲＰ）也发生剂量依赖性延长,但不存在像ＡＰＤ延长百分率那样的差别。此外,４种细胞ＥＲＰ所相当的复极化膜电位未受药物影响,从而避免了由于兴奋性恢复的不均一性,使ＡＶＮ区成为折返性心律失常的发源地．     

Some beneficial effects of aggregation in young larvae ofPryeria sinica moore (Lepidoptera: Zygaenidae)

The effects of group size on the survival and development of young larvae of Pryeria sinicaMoore were investigated by laboratory and field experiments. Under laboratory conditions, about 20% of isolated larvae died of unsuccessful feeding in the first instar, however, larvae survived successfully in aggregations of four or more individuals. In the field, larvae emerge in early spring and wait for new leaves to open before feeding. In this period, the larger the group size of hatchlings the survival rate became higher. The nest-web spun by hatchlings was considered to play an important role in protecting them from desiccation. In the period that larvae began to feed on leaves, more than 36 larvae are necessary to aggregate for the successful establishment of feeding groups. The nest-web played an important role also in the establishment of feeding group. However, the natural group size of the first instar larvae was larger than the minimum group size to spin a sound nest-web in the field experiment. On the other hand, in later stage, larvae in a large group did not have an excess advantage in survival or developmental rate over larvae in a small group. It was found that the experiments on survival and developmental rates could not explain the reason that this species maintain large compact groups in the most part of larval period.     

Dental anthropology and paleodemography of the precolumbian populations of hispaniola from the third millennium B.C. to the Spanish conquest

The demography and dental traits of the skeletal samples from the necropoles of Cueva Roja (IIrd millennium b.C.), El Soco (800 a.D) and Juan Dolio (1400 a.D.) have been analyzed. The preceramic sample from Cueva Roja consists of some 50 individuals, the one from El Soco consists of 158 individuals and the one from Juan Dolio of 108 individuals. The demographic analysis has revealed a slight improvement of life conditions from the pre-contact period to the beginning of the contact period. Dental metrical traits show a marked overlapping of the metrical data for the anterior teeth. A reduction can be noted for the posterior teeth, especially for the first molar, from the preceramic period to the later ceramic period. The analysis of nutritional stresses, through the study of dental enamel hypoplasias, reveals a high incidence of stress in the preceramic population. In the preceramic group, it peaks late in childhood (3.5—3.9 years of age) which could be caused by a delay in weaning. Instead the more recent groups (El Soco and Juan Dolio) show evidence of an earlier occurrence of hypoplasia. Both peak at 3.0–3.4 years of age. The frequencies of hypoplasias calculated by type of tooth are less in the Tainos groups than in the preceramic one. From of the data now available, we can suppose that an amelioration of life conditions occurred from the preceramic period to the later ceramic period. As regards the Tainos groups, a slight improvement in life conditions can be noted from the precontact period to the period immediately before the European colonization. The dental non-metric traits show a strong homogeneity within the Taino groups. However, the preceramic group shows more marked differences when compared to the others. This could be supposed to be due to a different demic background between the Tainos and the group from Cueva Roja.     

Differences in population parameters of twoTribolium castaneum strains in environments of different shapes

1. Survival and duration of development of two Tribolium castaneum strains were not the same when reared in environments of different shapes under the same external conditions.
2. The bb strain survived better in jars than vials. The ++ strain survived better in vials than in jars of type 3.
3. Both strains (as well as their hybrid (+b)) developed faster in vials (type 1) than in shallow jars (type 2). Both strains developed faster in jars of type 3 than in vials, at the low density. At the high density, the strains reacted differently: ++ developed faster in vials, but bb developed faster in jars.
4. Cultures of “selected” strains followed the population trends they exhibited in the selection experiments from which they came.
5. In both densities and in all environments, mean individual weight of ++ adults was always higher then that of bb, suggesting that this character is, at least in part, genetically determined.
6. The differences in survival and developmental period in environments of different shapes may be due to microclimatic differences between environments and to changes produced in them by the developing immatures.

     

第二语言语音获得的影响因素及其脑机制

本文综述了影响双语者第二语言语音获得的一些因素,包括双语者第二语言的获得年龄、居住时间长短、第一语言与第二语言两种语言语音系统的相似程度以及两种语言使用频率的高低等。此外,还介绍了此领域神经生理学研究获得的最新成果,从神经机制方面深入探讨这些影响因素对双语者语音系统组织的影响。     

Drosophila auraria复合种Period基因Thr-Gly区段的初步研究

测定了金色果蝇复合种（Drosophila auraria species complex）5个姐妹种（sibling species）和D.rufa的period(per)基因的Thr-Gly区段序列。该区段序列分析表明：DNA序列的碱其组成拥有果蝇其他基因的共同特点;颠换数多于转换数,两两种种间的颠换率与转换率的总比值为2～5,密码子第3位的颠换与转换的比值为2.5～5;同义替换/异义替换（Ks/Ka）值远大于10,且有的物种间根本不存在非同义突变,低的Ka值说明该复合种的per基因Thr-Gly区段在进化过程中可能承受着较强的选择压力。运用所得的核苷酸序列构建Drosophila auraria复合种的系统发育树,为澄清该类群的系统演化关系提供了新的线索。