SOME REMARKS ON CHENJIAWO FAUNA──On the First Appearance of Peking Man Fauna

I.CORRELATIONBETWEENL0ESSSECTI0NAND0XYGENIS0TOPESTAGESIntheYuanloessarea,manyscientiststhinkthatthesedimentsarecontinuousandtheclimaticrecordsareperfect.Thisdoesnotappeartobeaccurate.Sedimentationwasdiscontinuousinmanysections.Forexample,manyscientistsarguethatS2corresp0ndstooxygenisot0peStage7(Liu,l985,KuklaandAn,l989;Dingetal.,l990).lnfact,S2includesthreelayersfS2SSl,S2LLlandS2SS2.Dingetal.(l990)reportedthatthereisathickunitofloessbetweenS2SSlandS2SS2intheBaicao…     

Permeability Increase Induced by Escherichia coli Hemolysin A in Human Macrophages is Due to the Formation of Ionic Pores: A Patch Clamp Characterization

Escherichia coli hemolysin is known to cause hemolysis of red blood cells by forming hydrophilic pores in their cell membrane. Hemolysin-induced pores have been directly visualized in model systems such as planar lipid membranes and unilamellar vesicles. However this hemolysin, like all the members of a related family of toxins called Repeat Toxins, is a potent leukotoxin. To investigate whether the formation of channels is involved also in its leukotoxic activity, we used patch-clamped human macrophages as targets. Indeed, when exposed to the hemolysin, these cells developed additional pores into their membrane. Such exogenous pores had properties very different from the endogenous channels already present in the cell membrane (primarily K⁺ channels), but very similar to the pores formed by the toxin in purely lipidic model membranes. Observed properties were: large single channel conductance, cation over anion selectivity but weak discrimination among different cations, quasilinear current-voltage characteristic and the existence of a flickering pre-open state of small conductance. The selectivity properties of the toxin channels appearing in phospholipid vesicles were also investigated, using a specially adapted polarization/depolarization assay, and were found to be completely consistent with that of the current fluctuations observed in excised macrophage patches. Received: 14 August 1995/Revised: 2 October 1995     

黑龙江宁安盆地穆棱组及其孢粉型组合新发现

黑龙江宁安盆地是一个具有油气勘探远景的中小型盆地,主要目的层为下白垩统。新发现了一套相当于邻区穆棱组的地层,孢粉化石十分丰富,建立了５个孢粉组合带,通过对两口石油探井生物地层的研究,建立了该舅地新的地层层序,并对穆棱组的时代和沉积环境进行了讨论。     

河南济源晚石炭世太原组的一种复体四射珊瑚

Ａｃｒｏｃｙａｔｈｕｓ是一类块状体或丛状体的四射珊瑚，在北美分布于下石炭统，我国见于上石炭统，但丛状体的在我国系首次发现。在连续切片上，可见两个生长阶段，其繁殖方式有侧芽繁殖和边缘泡沫板内繁殖，系统分类上另置独立的科级分类。根据形态分析，该珊瑚栖息在动水，能量略高及食料丰富的浅水环境。当前标本为一新种：Ａ．ｊｉｙｕａｎｅｎｓｉｓｓｐ．ｎｏｖ．。     

Late Famennian gastropoda from south-west England

The gastropod fauna of the Upper Devonian Baggy and Pilton formations in south‐west England is revised and includes some 30 taxa. The topmost part of the Upper Famennian succession in Devon is represented by clastic near‐shore and shallow shelf sediments, indicating a short‐term transgressive phase (‘Strunian Transgression’). The sequence yields a highly diverse fauna dominated by brachiopods and ostracodes, locally supplemented by crinoids, bryozoans, trilobites and molluscs. The taxa ‘Patellostium’britannicum sp. nov., Angyomphalus (Angyomphalus) junius sp. nov. and Dictyotomaria eurocapillaria sp. nov. are erected; a junior homonym is replaced by Macrochilina? piltonensis nom. nov. The gastropod fauna displays an independent character, where latest Devonian faunal elements overlap with Late Palaeozoic taxa expressing a transition similar to that of the bivalves, brachiopods, echinoderms and corals, without a sharp faunal break at the Devonian/Carboniferous boundary. Apart from the Caenogastropoda, all subclasses of gastropods are represented. Members of the bellerophontoids, pleurotomarioids and loxonematoids are most abundant, followed by murchisonioids, naticimorphs, euomphalomorphs and platyceratoids. The various gastropod groups represent different ecological demands and trophic categories, and together with the accompanying fauna indicate that nearly all habitats and niches were occupied in the shallow South Laurussian Shelf.     

Analytical treatment of pattern formation in the Gierer-Meinhardt model of morphogenesis

Summary We first perform a linear stability analysis of the Gierer-Meinhardt model to determine the critical parameters where the homogeneous distribution of activator and inhibitor concentrations becomes unstable. There are two kinds of instabilities, namely, one leading to spatial patterns and another one leading to temporal oscillations. Focussing our attention on spatial pattern formation we solve the corresponding nonlinear equations by means of our previously introduced method of generalized Ginzburg-Landau equations. We explicitly consider the two-dimensional case and find both rolls and hexagon-like structures. The impact of different boundary conditions on the resulting patterns is also discussed. The occurrence of the new patterns has all the features of nonequilibrium phase transitions.     

A NEW GENUS OF CAPRINI (BOVIDAE, ARTIODACTYLA) FROM UPPER PLIOCENE OF YUSHE, SHANSI

<正> In the present paper a new caprine, Sinocapra minor gen. et sp. nov. is erected on the basis of several horn cores. The type specimen was collected by the Sino-American Palaeontology Expedition from the Upper Pliocene, Mazegou Formation, of Yunzhu Subbasin, Yushe Basin, Shansi province in 1988. All the other ones referred to the new genus were described and identified by Teilhard de Chardin and Trassaert (1938, p. 53, fig. 46) as Antilope gen. et sp. indet. They also came from Zhaozhuang, Yunzhu Subbasin and it is likely that they might be gathered from the same Formation as the type specimen judging by the yellow sandy clay filling into the horn cores. Magnetostratigraphic studies by Prof. N. Opdyke of the Yunzhu Subbasin indicates that this stratigraphic interval only includes the Gauss one, approximately 3.4 to 2.47 Ma. Accounts of the biostratigraphy and dating of Yunzhu Subbasin are giyen by Dr. R. H. Tedford and Dr. Z. Qiu in another paper.     

Negative air ions as a source of superoxide

The physico-chemical characteristics and possible formation mechanisms of negative air ions are considered. It was found that the products of oxygen and nitrogen negative ionization reduce ferricytochromec and nitroblue tetrazolium, and that these reactions were inhibited by superoxide dismutase. The interaction of negatively ionized oxygen with water led to hydrogen peroxide accumulation, which was inhibited by tetranitromethane or catalase. Nitrogen ionization under these conditions caused the formation of the hydrated electron e _aq ^— and the superoxide anion O ₂ ^— . The data obtained indicate that the biological activity of negative air ions may be dependent on superoxide. The generation of reactive oxygen ions in the gas phase and also at a gas/water interface is described. A scheme for superoxide production under oxygen and nitrogen ionization is proposed.     

Stimulation of the anaerobic growth ofSalmonella typhimurium by reduction ofl-carnitine,carnitine derivatives and structure-related trimethylammonium compounds

In view of the development of al-carnitine deficiency, the metabolism ofl-carnitine and structure-related trimethylammonium compounds was studied inSalmonella typhimurium LT₂ by means of thin-layer chromatography (TLC).l-Carnitine, crotonobetaine and acetyl-l-carnitine stimulated the anaerobic growth in a complex medium significantly. The stimulation depended on the formation of -butyrobetaine. The reduction ofl-carnitine proceeded in two steps: (1) Dehydration of thel-carnitine to crotonobetaine, (2) hydrogenation of crotonobetaine to -butyrobetaine. The reduction of crotonobetaine was responsible for the growth stimulation. Terminal electron acceptors of the anaerobic respiration such as nitrate and trimethylamine N-oxide, but not fumarate, suppressed the catabolism ofl-carnitine completely. Glucose fermentation, too, inhibited the reduction ofl-carnitine but optimal growth with a high carnitine catabolism was achieved byd-ribose. The esters of carnitine with medium- and long-chain fatty acids inhibited the growth considerably because of their detergent properties.Abbreviations TLC thin-layer chromatography     

内蒙古达茂旗巴特敖包地区包尔汉图剖面牙形刺生物地层

内蒙古达茂旗(达尔罕茂明安联合旗)巴特敖包地区志留纪、泥盆纪碳酸岩相地层发育,本区珊瑚、腕足类、层孔虫等底栖大化石的研究工作已有一定基础。但志留纪、泥盆纪地层在时代确定和对比上还存在很多问题,必须用主导化石门类牙形刺加以解决。研究表明：包尔汉图剖面的顶部属泥盆系无疑,应归入阿鲁共组,而不是西别河组;巴特敖包地区的海侵,始于罗德洛统卢德福德阶(Ludfordian)早期。本剖面没有发现文洛克世和罗德洛世早期的海相沉积。本文描写了一个志留纪牙形刺新种：Ozarkodina uncrispa sp．nov．。