Age determination and planktonic foraminifera og ODP Site 159-958

Site 958 was drilled to monitor the late Neogene history of both continental aridity in northwestern Africa and the Canary Current distant from nearshore upwelling. Based on magnetostratigraphy, biostratigraphic datums, variations in carbonate, coarse fraction components, and the species composition of planktonic foraminifers, as well as using the d18O records of Globigerinoides ruber (white), we established a splice between Holes 958A and 958B and a stratigraphic age scale deciphering Milankovitch cycles. Over the last 630 k.y., sedimentation rates amount to 2.9 cm/k.y., and to 2.05-2.53 cm/k.y. back to the base of the Pleistocene. Extremely low rates of 0.4 cm/k.y. and a reworking of fossils mark the late Pliocene. The first continuous, long, sea-surface temperature (SST) record from the center of the Canary Current, which is based on foraminifer species census data, depicts a general temperature decrease in the late Pliocene, lower SST and high seasonalities of up to 6°C ~2.0-1.6 Ma, a warmer interval from 1.6 Ma to ~0.85 Ma, again lower SST and higher seasonalities until 0.33 or 0.26 Ma, and a final warmer interval, lasting until at least 50 ka, possibly reflecting the attenuated dynamics of the Canary Current. Especially over the last 400 k.y., since Stage 11, glacial stages are hardly reflected by cold SST cycles, except for various abrupt and extremely short cooling events amounting to D6°C, which possibly result from North Atlantic Heinrich events. Similar, but not necessarily synchronous, events of short-term, extremely high values occur in the paleoproductivity and (d13Cbased) paleonutrient records, which indicate a generally low primary production averaging to 180 g C m**-2 yr**-1 at 50-330 ka and about 300 g C m**-2 yr**-1 back to the base of the Pleistocene. Near 1.2-1.6 Ma, the grain-size and magnetic susceptibility records document a significant increase in the discharge of south Saharan/Sahelian dust, possibly linked to increasing aridity.

Sea surface temperature and stable isotopes from 9 cores of the Northeastern Atlantic

Temporal and spatial patterns in eastern North Atlantic sea-surface temperatures (SST) were reconstructed for marine isotope stage (MIS) 11c using a submeridional transect of five sediment cores. The SST reconstructions are based on planktic foraminiferal abundances and alkenone indices, and are supported by benthic and planktic stable isotope measurements, as well as by ice-rafted debris content in polar and middle latitudes. Additionally, the larger-scale dynamics of the precipitation regime over northern Africa and the western Mediterranean region was evaluated from iron concentrations in marine sediments off NW Africa and planktic d13C in combination with analysis of planktic foraminiferal abundances down to the species level in the Mediterranean Sea. Compared to the modern situation, it is revealed that during entire MIS 11c sensu stricto (ss), i.e., between 420 and 398 ka according to our age models, a cold SST anomaly in the Nordic seas co-existed with a warm SST anomaly in the middle latitudes and the subtropics, resulting in steeper meridional SST gradients than during the Holocene. Such a SST pattern correlates well with a prevalence of a negative mode of the modern North Atlantic Oscillation. We suggest that our scenario might partly explain the longer duration of wet conditions in the northern Africa during MIS 11c compared to the Holocene.

Diário da Constituinte [gravação de vídeo] : [programa n. 159]

Está pronto o calendário das sessões extraordinárias para o debate dos temas polêmicos da Assembleia Nacional Constituinte. O Deputado Bocayuva Cunha (PDT-RJ) espera a participação popular e que a sociedade possa acompanhar a posição dos partidos e dos constituintes em relação aos temas a serem debatidos. O PT quer discutir mais os temas sociais. O Deputado Vladimir Palmeiras (PT-RJ) declara que a bancada terá uma intervenção mais sistemática no Plenário, no sentido de afirmar que a redução da jornada de trabalho e a estabilidade no emprego são pontos essenciais para discussão do texto constitucional. Reunião do Grupo Interpartidário, com representantes do PMDB, PT, PDT, PCB e PFL, buscam o consenso. O Deputado Antonio Brito (PMDB-RS) afirma que a sabedoria de uma Constituinte é tentar estabelecer o que o país tem em comum, para criar uma Constituição duradoura. Na reunião interpartidária, os constituintes debateram os artigos do anteprojeto que tratam da censura, da criação de um conselho de comunicação social e da reforma agrária e definiram dezenove pontos em torno dos quais buscarão uma posição de consenso nas votações em Plenário. O Deputado Roberto Freire (PCB-PE) destaca a importância do diálogo entre os partidos. O Deputado Mário Covas (PMDB-SP) declara que há uma preocupação comum que é a de ter uma Constituição que reflita os anseios da sociedade brasileira. O Deputado Plínio Arruda Sampaio (PT-SP) afirma que há uma intenção dos grupos progressistas de comporem uma grande aliança para que esta Constituição represente um avanço. O Deputado Alceni Guerra (PFL-PR) defende que a Constituição deve representar o que pensa a sociedade brasileira e deve também ser flexível, para que tanto um governo de esquerda como um de direita possa governar o país. O Deputado Antonio Brito (PMDB-RS) ressalta que, pela primeira vez, os partidos estão negociando e que é isto o que deve ser uma Constituinte. Dom Luciano Mendes, Presidente da Confederação Nacional dos Bispos do Brasil (CNBB), entrega três emendas populares ao Presidente da Assembleia Nacional Constituinte (ANC) Ulysses Guimarães . Dom Luciano ressalta a importância das emendas populares.

The transport of aquatic animals by birds. [Translation from: Binnengewaesser 18, 156-159, 1950.]

A great deal has been written on the part which birds play in the dispersal of freshwater fauna. This article summarises literature on the dispersal of aquatic animals by birds and aquatic insects.

栉角雪萤的荧光酶基因结构及其系统发育分析

短角窗萤属是萤科第四大属,但未见有该属物种荧光酶基因的研究报道.通过对总基因组的PCR扩增,对该属的栉角雪萤荧光酶基因进行了测序分析.基因序列长1 958 bp.与已知荧光酶基因进行同源性比较后推断,栉角雪萤的荧光酶基因由7个外显子和6个内含子组成,编码547个氨基酸残基;由推导的氨基酸序列进行同源性比较后发现,栉角雪萤的荧光酶基因与同一亚科中Lampyrini族和Cratomorphini族分别具有93-94%和92%相似性,而与北美萤火虫Photinus pyralis(Photinini族)的相似性较低(83%).系统发育分析进一步表明栉角雪萤与Pyrocoelia、Lampyris、Cratomorphus和Photinus同属于萤亚科,且与前3个属的亲缘关系较近.这在一定程度上与形态(Branham & Wenzel,2003)及线粒体DNA(Li et al,2006)系统发育分析所得结果一致.

云南鸟类一新记录——白翅浮鸥

在执行全球环境基金(GEF)资助、世界银行管理、中国科学院昆明动物研究所承担的"滇池淡水水生生物多样性恢复项目"中,对滇池东南岸晋宁县新街乡下梁王的湿地生物多样性恢复示范基地进行物种监测时,曾经于2006年6月19日观察到一种较小的鸥类.

中能区~(40)Ar + ~(197)Au/~(159)Tb/~(nat)Ag反应中高激发热核性质研究

通过对中能区Ar+Au/Tb/Ag反应中高激发核的发射时标、发射次序、发射机制、核温度、集体运动等衰变特性的研究，提取了轻粒子和中等质量碎片（IMF）的发射时间，IMF发射时间随束流能的升高而变短，发射机制逐渐由相继衰变过渡至多重碎裂。研究了轻粒子和碎片间的发射次序，对高能粒子和碎片，轻粒子先于碎片发射，而低能时，则为碎片先于轻粒子发射。IMF发射成分与角度和碰撞参数有关，前角区来自于弹核碎裂，后角区来自于类靶热核的蒸发。在平面和出平面研究表明，中速粒子和碎片为在平面发射占主导，即存在类转动效应；对轻粒子，转动效应随粒子质量增加而增加；对中速产物均观测到该效应随碰撞参数饿增大而增大。采用几种不同的方法提取了热核的核温度，研究了不同方法之间的区别。