周口店山顶洞人齿列

在近 10年里 ,有许多文章涉及解剖学上现代东亚人及其衍生人群起源问题 (Akazawa,Aoki and Kimura,1992 ;Brown,1998,1999?;Hanihara,1994;Howells,1995 ;Neves,19 98;Omoto,1995 ;Pope,1992 ;Turner,1992 a,1992 b;Wu,1998)。在许多论文中关注了周口店山顶洞的晚更新世化石 (Black,1934 ;Pei,1934 ;Weidenreich,1938— 39)。尽管原来的标本在战时失踪 ,但直接从 30年代制作模型上已经进行过许多考察和分析 ,或者利用了 Weidenreich的对原标本的测量和观察资料进行分析 ,或者兼而用之 (Brown,19 98;Howells,1995 ;Kaminga and Wrigh…     

东昆仑山西段上石炭统的四射珊瑚

青海柴达木盆地西南缘祁曼塔格山一带的上石炭统分下部缔敖苏组和上部四角羊沟组,该组的珊瑚化石自下而上可分两组合：１）Ｂｒａｄｙｐｈｙｌｌｕｍ ｓｔｅｒｅｏｍａｒｇｉｎａｔｕｍ－Ｃｙｓｔｏｐｈｏｒａｓｔｒａｅａ ｍｏｌｌｉ－Ｓｋｏｌｅｋｏｐｈｙｌｌｕｍ ｂｕｌｌｉｔａｂｕｌａｔｕｍ组合,２）Ａｍｙｇｄａｌｏｐｈｙｌｌｏｉｄｅｓ ｍａｎｇｎａｉｅｎｓｅ－Ｎｅｏｋｏｎｉｎｃｋｏｐｈｙｌｌｕｍ ｐｅｔｉｌｕ     

Geographic control on phenotype expression. The case of Hybonoticeras mundulum (Oppel) from the Mexican Altiplano

Hybonoticeras mundulum (Oppel) (m) s.s. is reported from the Mexican Altiplano on the basis of material collected bed-by-bed in sections in the States of Durango and Zacatecas. The known range of this species in the Mexican Altiplano is interpreted to be uppermost Kimmeridgian (upper to uppermost Beckeri Zone) to lowermost Tithonian (basal to lower Hybonotum Zone). The Mexican specimens studied are the most complete and valuable collection of H. mundulum (Oppel) s.s. known from a given area, and reveal that Mexican populations show phenotypic features different from European ones. Vicariant events accord with data available about the areal and biostratigraphic distribution of this species, as well as with the combination of allocyclic and autocyclic factors influencing Mexican seas, the breaking of populations rather than colonization events, and the impoverished ammonite assemblages showing endemic traits within the stratigraphic interval studied.     

基于线粒体控制区序列的黄河上游厚唇裸重唇鱼种群遗传结构

采集黄河上游厚唇裸重唇鱼(Gymnodiptychus pachycheilus)甘肃玛曲群体,测定其线粒体DNA控制区序列,并从GenBank中下载青海玛多和贵德等3地2个群体的同源序列,分析该物种的遗传多样性、遗传结构及其演化历史.从81条729 bp序列中,检测到26个变异位点(占3.57％),碱基序列总的单倍型多样性为0.844,核苷酸多样性为0.0054,界定了34个单倍型,有1个广布单倍型H2,占所有样品的38.27％.单倍型网络图图显示单倍型没有明显的亲缘地理格局,H2处于中心,呈星状发散,系统发育分析没有显示出单倍型与地理位置的对应关系.AMOVA分析显示变异主要来自地理区内群体间,歧点分布和中性检测显示厚唇裸重唇鱼近期经历了种群扩张.分析表明黄河上游3地种厚唇裸重唇鱼种群未出现分化,建议应作为一个整体进行保护.     

Late Paleozoic faunal, climatic, and geographic changes in the Baoshan block as a Gondwana-derived continental fragment in southwest China

The Carboniferous and Permian of the Baoshan block consist of three major depositional sequences: a Lower Carboniferous carbonate sequence, a Lower Permian siliciclastic sequence, and a Middle Permian carbonate sequence. These three sequences were interrupted by two major regressive events: first, the Namurian Uplift ranging in age from Serpukovian to Gzhelian, and second, the Post-Sakmarian Regression occurring probably at Artinskian time in the Baoshan block, although the precise time interval of the latter event is still unclear. The Baoshan block is characterized by warm-water, highly diverse and abundant faunas during the Early Carboniferous, by cold-water and low diversity faunas during the Early Permian, and by possibly warm-water but low diversity faunas during the Middle Permian. The Sweetognathus bucaramangus conodont fauna constrains the upper boundary of the diamictite-bearing siliciclastic deposits (Dingjiazhai Formation) to the Sakmarian to early Artinskian, as well as the eruption of the rifting basalts (Woniusi Formation) to, at least, the post-early Artinskian. Paleozoogeographically, affiliation of the faunas in the Baoshan block changed from Eurasian in the Early Carboniferous, to Peri-Gondwanan in the Early Permian, and to Marginal Cathaysian/Cimmerian in the Middle Permian. Cimmerian blocks have more or less comparable geohistory to one another in the Carboniferous and Permian. During the Middle Permian, the eastern Cimmerian blocks such as Sibumasu (s.s), Baoshan, and Tengchong are not far from the palaeoequator, but apparently more distant than the western Cimmerian blocks based on the presence or absence of some index taxa such as the fusulinaceans Eopolydiexodina and Neoschwagerina, and the corals Thomasiphyllum and Wentzellophyllum persicum.     

Joint evolution of predator body size and prey-size preference

We studied the joint evolution of predator body size and prey-size preference based on dynamic energy budget theory. The predators’ demography and their functional response are based on general eco-physiological principles involving the size of both predator and prey. While our model can account for qualitatively different predator types by adjusting parameter values, we mainly focused on ‘true’ predators that kill their prey. The resulting model explains various empirical observations, such as the triangular distribution of predator–prey size combinations, the island rule, and the difference in predator–prey size ratios between filter feeders and raptorial feeders. The model also reveals key factors for the evolution of predator–prey size ratios. Capture mechanisms turned out to have a large effect on this ratio, while prey-size availability and competition for resources only help explain variation in predator size, not variation in predator–prey size ratio. Predation among predators is identified as an important factor for deviations from the optimal predator–prey size ratio.     

通过C27/C29甾烷和有机碳同位素来判断早古生代和前寒武纪的烃源岩的生物来源

在早古生代与前寒武纪的石油与源岩中,经常出现令人困惑的C29甾烷优势,而在有机地球化学中C29甾烷优势被认为是陆相有机质输入的标志。作者通过对比文献中各种海相藻类的热模拟产物分析,提出了早古生代与前寒武纪的石油与源岩中C29甾烷优势主要来源于浮游绿藻的观点,并通过C27甾烷/C29甾烷的比值提出了区分早古生代及前寒武纪石油源岩沉积环境的方法,对中国南方前寒武纪和早寒武世黑色岩系的有机地球化学分析也支持上述推断。此外,本文还提出了用有机碳同位素来进一步区分C29甾烷优势生物来源的方法。     

Hydrologic Regime Controls Soil Phosphorus Fluxes in Restoration and Undisturbed Wetlands

Many wetland restoration projects occur on former agricultural soils that have a history of disturbance and fertilization, making them prone to phosphorus (P) release upon flooding. To study the relationship between P release and hydrologic regime, we collected soil cores from three restoration wetlands and three undisturbed wetlands around Upper Klamath Lake in southern Oregon, U.S.A. Soil cores were subjected to one of three hydrologic regimes—flooded, moist, and dry—for 7.5 weeks, and P fluxes were measured upon reflooding. Soils from restoration wetlands released P upon reflooding regardless of the hydrologic regime, with the greatest releases coming from soils that had been flooded or dried. Undisturbed wetland soils released P only after drying. Patterns in P release can be explained by a combination of physical and biological processes, including the release of iron‐bound P due to anoxia in the flooded treatment and the mineralization of organic P under aerobic conditions in the dry treatment. Higher rates of soil P release from restoration wetland soils, particularly under flooded conditions, were associated with higher total P concentrations compared with undisturbed wetland soils. We conclude that maintaining moist soil is the means to minimize P release from recently flooded wetland soils. Alternatively, prolonged flooding provides a means of liberating excess labile P from former agricultural soils while minimizing continued organic P mineralization and soil subsidence.     

青年咽部菌群分布状况

目的调查健康青年上呼吸道的微生物群分布,寻找优势菌群,为微生态方法治疗呼吸道感染性疾病提供科学依据。方法随机自愿原则选取沈阳医学院学生61名,采集咽后壁标本分离培养并生化鉴定。结果青年咽后壁共检出19个菌属,42个菌种。需氧菌的95％可信区间为（4．7×10^6,6．8×10^6）CFU／mL,厌氧菌的95％可信区间为（5．9×10^6,8．4×10^6）CFU／mL;需氧菌菌群密度为4．8816±1．0251,厌氧菌菌群密度为5．1347±0．9118。需氧菌中链球菌属检出率为100％,其次为奈瑟球菌属（77．4％）、葡萄球菌属（33．9％）。链球菌中缓症链球菌和口腔链球菌、奈瑟球菌属中的灰色奈瑟球菌的检出率与构成比均较高。厌氧菌中检出率与构成比较高是的韦荣球菌属、拟杆菌属、孪生球菌和放线杆菌属。结论青年上呼吸道菌群种类复杂多样;需氧菌中的口腔链球菌、缓症链球菌、灰色奈瑟球菌,厌氧菌中的韦荣球菌属、拟杆菌属、孪生球菌属为优势菌群,对于维护上呼吸道微生态平衡可能起重要的作用。     

上扬子区奥陶纪三叶虫属Hexacopyge的新材料

描述上扬子区鄂西和湘西中及晚奥陶世桨肋虫类三叶虫Hexacopyge的 5个种 ,包括 2新种 ,即H .turbiniformis和H .yichangensis;讨论Hexacopyge的定义及其与相关属的关系。Hexacopyge在区内分布广、演化快 。