寒武纪早期宽川铺生物群中圆管螺化石显微结构及显微谱学分析

陕南寒武系底部宽川铺组不仅保存了大量的小壳化石,还以磷酸盐化的方式立体保存了多种软躯体动物的胚胎和成体化石,为研究早期动物矿化模式、个体发育方式以及动物躯体构型的早期辐射过程提供了非常关键的信息。然而宽川铺生物群的研究大多聚焦于化石系统分类及亲缘关系探索,对生物群的沉积背景、埋藏过程和保存模式的分析甚少。本文以宽川铺生物群的核心产出层位——陕西省西乡县大河镇宽川铺组下部磷质碎屑灰岩为研究对象,对其中的一类管状化石圆管螺及其围岩进行了显微结构学和显微谱学综合分析,获得了化石显微结构和关键结构对应的元素、矿物成分等信息,讨论了管状化石圆管螺的埋藏过程和保存模式,并在此基础上对其生物学特征进行了初步探讨。该研究对理解宽川铺生物群的埋藏机制提供了新的线索。     

川南马边老河坝磷矿区麦地坪组中管状化石壳体成分特征及与围岩的关系

小壳化石壳体成分的鉴定对于揭露寒武纪早期小壳动物群的演化具有重要意义。本文通过岩石薄片观察,分析了川南马边老河坝磷矿区麦地坪组中不同岩性管状化石壳体成分特征。结果显示,不同围岩中管状化石壳体成分不同:围岩为磷块岩,管状化石中间层保存成分以胶磷矿为主,夹白云石晶体;围岩为白云岩,管状化石中间层保存成分以胶磷矿为主;而围岩为灰岩,管状化石的中间层保存成分以胶磷矿或方解石为主。后期磷酸盐化作用改造明显:壳体内部碳酸盐矿物被胶磷矿或微晶质石英交代、磷质壳内部被白云石或隐晶质燧石交代现象发育,其中以碳酸盐矿物被胶磷矿交代的现象居多;部分管状化石的壳体出现模糊的多圈层结构和壳体增厚的现象;壳体内部填充的胶磷矿在围岩中普遍出现。壳体保存成分与围岩性质密切相关,研究区内保存的管状化石壳体成分绝大部分经历了磷酸盐化作用。     

贵州剑河寒武系凯里组脊状单臂螺(Haplophrentis carinatus)埋藏特征及与始海百合共生关系探讨

贵州剑河寒武系凯里组软舌螺化石丰富、埋藏形式多样,其中以脊状单臂螺Haplophrentis carinatus化石数量最多、保存最为完整。过去有关学者对凯里组单臂螺化石的研究主要集中在化石分类学方面,对脊状单臂螺埋藏特征及与其他生物共生关系缺乏深入探讨。本文对324块脊状单臂螺化石标本进行系统研究对比后发现,凯里组脊状单臂螺口盖化石埋藏形式有四类:口盖单独保存、口盖以内模或外模化石形式保存、口盖与锥壳完全绞合保存、口盖与锥壳不完全绞合保存;附肢保存较少;锥壳多以内模化石形式保存;脊状单臂螺内模化石与印痕化石上普遍出现类似软体保存形成的三分叉结构,这类三分叉结构属于后期埋藏因素造成的次生结构。文中还对脊状单臂螺与始海百合共生关系进行探讨,并将二者共生关系归为偏害共生。     

云南早寒武世澄江化石库中两种埋藏相的化石定量分析

通过昆明海口马房村同一个采坑的化石连续采集和统计,对澄江化石库中两种埋藏相(以事件层泥岩和背景层泥岩所代表)内化石保存和组合特征进行定量研究,结果表明:(1)事件层内化石量并不随单一事件层厚度变化而变化。物种在剖面上不同层位的事件层内分布不均匀,表现为单层富集现象;而背景层内的化石含量与背景层的沉积厚度有关,背景层的沉积厚度越厚,化石数量就越多。(2)事件层与背景层内化石组合和结构存在很大差异。事件层内化石组合与背景层内化石组合相比具有更多的物种组成和更复杂的古群落结构;而背景层内化石组合面貌单调,在剖面上保持稳定。(3)事件层内化石生物体腐烂发生在埋藏之后,绝大多数化石生物是被活埋后保存下来的;而背景层内化石主要表现为外壳和弱矿化有机质生物表皮在海床表面长时间停滞而堆积形成,明显受到时间均衡作用(time-average)的影响。(4)事件层内化石在埋藏前无搬运作用,或发生近原栖息地的快速搬运,埋藏后无生物扰动。背景层内大量壳体相连的双瓣壳节肢动物化石和完整海绵体化石的存在则表明,背景层代表一个低氧、低能并具有有限生物扰动的沉积环境。     

华南埃迪卡拉纪化石保存方式及其时空分布

埃迪卡拉纪化石保存方式具有多样性,包括:磷酸盐化、有机碳质压膜、黄铁矿化、硅化、以及粘土矿物交代。文中综述了以上各种化石保存方式在地层中的时代分布规律、埋藏特征和形成机理,并分析了这些类型的化石库在我国埃迪卡拉纪地层中的地理分布规律和埋藏学意义。分析结果表明:华南埃迪卡拉纪化石库的保存方式主要以有机碳质压膜为主;磷酸盐化和硅化保存方式分布较广;黄铁矿化和粘土矿物交代方式在中国埃迪卡拉纪地层保存较少。有机碳质压膜、黄铁矿化多见于粉砂岩、泥岩中;磷酸盐化、硅化多出现于磷块岩、燧石层或碳酸盐岩的磷质、硅质结核中,化石多为微体化石。另外,多种化石保存方式常常同时出现在同一化石库中,形成复合式的保存模式。     

陕西宁强埃迪卡拉纪晚期高家山生物群中黄铁矿化化石的成岩及风化过程

陕南埃迪卡拉纪晚期的高家山生物群中部分化石以黄铁矿化三维立体保存软躯体管状化石为主要特征。对野外识别出的具有不同风化程度的3类粉砂岩进行了详细的手标本特征对比和扫描电子显微镜测试对比研究。锥管虫（Conotubus）的化石成岩学特征表明黄铁矿最先沉淀,随后方解石充填于黄铁矿留下的空隙或空腔中。这些化石所经历的第一期风化作用相对较弱,保留了大量的原始化石成岩学信息;第二期风化作用则可能形成于一个氧化条件较强的环境中。     

贵州寒武系杷榔组杷榔化石库埋藏学初步研究———以剑河辣子寨剖面为例*

贵州剑河辣子寨村辣子寨剖面杷榔组的杷榔动物群是近期发现的一个化石丰度较高且较复杂多样的动物群。该产地的化石库含有两个化石富集的层位,即下化石层和上化石层。通过对两个化石富集层的岩石结构、构造、沉积特征、生物类群组成及化石丰度和保存特征等方面的分析研究表明,下化石层与上化石层内化石组合和埋藏特征存在较大差异。下化石层类群组成多样、化石丰度较高,以掘头虫类三叶虫、三叶形虫Naraoia、大型双瓣壳节肢动物Isoxys、Tuzoia及古蠕虫、海绵等为主,且化石主要保存在事件沉积层内,保存质量较好,为外陆棚沉积环境下大量生物个体发生原位快速沉积埋藏作用形成。而上化石层内化石以具硬壳的三叶虫为主,有较大的埋藏量,少量或碎片状的Naraoia,Isoxys,且这类化石数量少,主要在背景层中保存,可能为静水沉积时,沉积界面积累了大量生物遗体并暴露于基底表面一定时间后,再被沉积物逐渐堆积掩埋而形成,为生物遗壳的原位或近原位埋藏。     

贵州寒武纪杷榔组古蠕虫类埋藏特征及意义*

贵州剑河寒武纪杷榔组辣子寨剖面含有丰度较高的古蠕虫类化石。化石鉴定为Wronascolex geyiensis, 主要保存在三个层位。在对三个层位的岩石、沉积特征、化石成因及埋藏特征探讨分析后, 证实W. geyiensis化石保存于快速的沉积事件导致的浊流沉积层内, 而化石埋藏的完美程度受到成岩过程中埋藏位置、沉积物中矿物结晶和充填方式的影响, 这些后期的成岩、成矿作用对先期形成的化石精细结构产生了直接和间接的破坏作用。本文通过对W. geyiensis化石体上黏土矿物、草莓状黄铁矿、自形–半自形黄铁矿的成因分析后, 获得最适合保存软躯体化石的环境应该为缺氧且生物体与孔隙水中的硫酸盐无接触的原地和近原地埋藏条件。     

节肢动物肠道及腹神经索的降解实验*

节肢动物的内部器官组织, 如消化系统和神经系统等精细结构在寒武纪化石中的保存特征对探索早期生命和地球环境的演化具有重要意义。近年来, 其原始形态与保存机理被广泛讨论, 说明此类型软躯体组织的保存行为还需多方面的实验和理论探索。实验埋藏学作为埋藏学的分支, 为解释生物化石化过程中解剖结构的变化及相应特异埋藏化石库的形成提供了重要理论支撑和实验技术手段。本文以节肢动物南美白对虾的肠道和腹神经索为材料, 在不同温度及组合条件下进行埋藏学实验, 以观察此类生物软组织的降解过程。实验结果显示, 肠道和腹神经索在不同温度下的降解趋势相似, 但降解速率不同: 肠道和腹神经索在25℃条件下的降解速率和降解程度明显大于其在10℃条件。同一温度条件下, 肠道与腹神经索的降解程度存在早期差异; 10℃条件下, 反应产生的微生物膜形态及规模有所不同, 肠道-腹神经索组合产生的微生物膜规模远大于肠道、腹神经索的单独处理组, 且难以辨认。由此可见, 温度是影响肠道和腹神经索降解速度和程度的重要因素。此外, 微生物在生物内部器官组织降解过程中起到了重要的生化作用。生物器官组织的降解过程, 以及不同条件下微生物膜的形成对化石的形态特征尤其是内部精细结构的保存解释具有重要影响。     

陕南张家沟剖面寒武纪早期微体化石Olivooidesmultisulcatus的新材料*

陕南西乡张家沟剖面寒武系下部统宽川铺组发现了大量特异埋藏化石,这些珍贵化石为三维磷酸盐化精美保存,在探索早期生命起源与演化方面意义重大,也是早寒武世前三叶虫时代生物地层对比的重要依据。本文主要对其中一类保存有软躯体的特异埋藏Olivooides multisulcatus Qian,1977进行描记,该类化石1977年曾在陕西宁强宽川铺生物群首次报道,与本文描记的化石类型相同,产地不同,因而具有地层对比意义。根据在西乡生物群发现的新材料,与Olivooides multisulcatus进行特征对比,对属征及种内变异特征进行了补充。     

Books

Book reviewed in this article: de Duve, Chr. (1986): Die Zelle — Expedition in die Grundstruktur des Lebens (A guided tour of the living cell. Scientific American Books Inc., New York 1984, übersetzt von E. D. JARASCH). Laudien, H., ed. (1986): Temperature relations in animals and man (Thermobiologie von Tieren und Menschen). Biona report 4 (series ed. W. NACHTIGALL). Gwinner, E. (1986): Circannual rhythms — endogenous annual clocks in the organization of seasonal processes (Jahresrhythmen. Die Steuerung jahres-zeitlicher Abläufe durch innere Uhren). Sawyer, R. T. (1986): Leech biology and behaviour (Biologie und Verhalten von Egeln). Vols. 1–3. Dreyer, W. (1986): Die Libellen. Handbuch der Libellenkunde (Handbook of European dragonflies and damselflies). Bryden, M. M., & R. Harrison, eds. (1986): Research on dolphins (Untersuchungen an Delphinen). Endler, J. A. (1986): Natural selection in the wild (Natürliche Auslese in freilebenden Populationen). Provine, W. B. (1986): Sewall WRIGHT and evolutionary biology (S. WRIGHT, Biographie eines Evolutionsbiologen). Wright, S. (1889): Evolution: selected papers (Ausgewählte Schriften zur Evolutionsbiologie), edited and with introductory materials by W. B. PROVINE.     

Comparison of the activity of short stay independent hospitals in England and Wales, 1981 and 1986.

From a sample of 19,000 treatment episodes at 183 of the 193 independent hospitals with operating facilities in England and Wales that were open during 1986 it is estimated that 404,000 inpatients were treated in 1986 (an increase of 48% since 1981) and 99,000 day cases (an increase of 112%). It was found that the procedure most commonly performed was abortion, though this made up only 19% of the total caseload in 1986 compared with 30% in 1981, otherwise the case mix in 1986 was similar to that in 1981. Fewer patients came from overseas in 1986 than in 1981, but the distribution by age and sex remained the same, with three quarters of the patients aged between 15 and 65. The estimated bed occupancy in the independent hospitals in 1986 was less than 60% nationally and only 52% in the Thames regions. It is concluded that in these five years the nature of the independent hospital sector changed little, and in 1986 the activity still consisted largely of routine cold elective surgery for people of working age, and the regional differences in admission rates to independent hospitals were nearly as great as in 1981.     

Patient characteristics and clinical caseload of short stay independent hospitals in England and Wales, 1992-3.

OBJECTIVE--To describe and quantify the patients and clinical activities of independent short stay hospitals. DESIGN--Retrospective survey of hospital records for sampled periods of one financial year and comparison with data from 1981 to 1986. SETTING--217 independent hospitals in England and Wales, 1992-3. MAIN OUTCOME MEASURES--Distributions of sex, age groups, and areas of residence of patients, clinical procedures, financial provision. RESULTS--Data were obtained from 201 (93%) hospitals. An estimated 429,172 inpatients (7% more than 1986) and 249,531 day cases (an increase of 154%) from 1986 were treated in the year. The number of overseas patients was half that in 1986. Clinical case mix remained similar to 1986. Abortion remained the commonest procedure (13% v 19% in 1986). Lens operations, heart operations, endoscopies, and non-surgical cases showed the largest increases from 1986. Proportionately more overseas patients had abortions (30% v 12% for England and Wales residents) and they received 41% of coronary artery bypass grafting. Three quarters of the patients were aged 15-64. The proportion of patients aged over 65 had changed little (19% v 17% in 1986). Estimated average bed occupancy was only 48%. Only one in 20 patients was treated under NHS contract; 90% of episodes were funded through private health insurance. CONCLUSIONS--The demand for treatment in private hospitals continues to increase despite additional investment in the NHS, but the overseas market is falling. Overall, the range of clinical activity has changed little.     

Epidemiological analysis of testicular malignant neoplasm incidence and mortality in Poland 1963-1986

Epidemiological analysis of both morbidity and mortality rates for testicular cancer in Poland between 1963 and 1986 was carried out. A particular attention was drawn to the period between 1981 and 1986, when a program of combined chemotherapy and surgery was introduced in Poland. The study aimed at analysing an effect of this combined treatment on mortality rate for testicular cancer. Between 1963 and 1986, a constant increase in morbidity for the testicular cancer was noted. Mortality rate increased between 1963 and 1983. This trend was inhibited between 1984 and 1986. "Splitting" of the morbidity and mortality curves was observed between 1984 and 1986. A decrease in mortality rate was noted at the constant morbidity for testicular tumors. It was particularly clear in younger age groups (15-39 years), as well as older age groups (60-64 years and over 75 years). A decrease in mortality rate for testicular tumors within 1984-1986 may be attributed to the introduction of combined treatment in Poland.     

Reviews

Book reviewed in this article: Books: Breipohl , W., ed. (1986): Ontogeny of olfaction. Principles of olfactory maturation in vertebrates (Die Entwicklung des Geruchsinnes bei Wirbeltieren). Books: Huntingford , F. A., & A. K. Turner (1987): Animal conflict (Konflikt und Angriff bei Tieren). Animal Behaviour Series. Books: Taylor , F., & R. Karban, eds. (1986): The evolution of insect life cycles (Ökologische Anpassung der Entwicklungszyklen von Insekten). Proceedings in Life Sciences. Books: Danthanarayana, W., ed. (1986): Insect flight: dispersal and migration (Insektenflug: Verbreitung und Wanderungen). Books: Miller , J. R., & T. A. Miller, eds. (1986): Insect-plant interactions (Beziehungen zwischen Insekten und Pflanzen). Books: Hepburn , H. R. (1986): Honeybees and wax. An experimental natural history (Honigbienen und Wachs - experimentelle Naturgeschichte). Books: Pitcher , T. J., ed. (1986): The behaviour of teleost fishes (Verhalten von Knochenfischen). Books: Nettleship , D. N., & T. R. Birkhead (1985): The Atlantic Alcidae (Die Alkenvogel des Atlantik). Books: Warhol , A., & K. Benirschke (1986): Vanishing animals (Erlöschende Tierarten).     

Family doctors and change in practice strategy since 1986.

OBJECTIVES--To investigate the changes in practice strategy that have taken place since 1986. DESIGN--Comparison of practices in 1986 and 1992. SETTING--93% of group practices (26 practices) in a single family health services authority. MAIN OUTCOME MEASURES--Changes in staffing, premises, equipment, clinic services, and incomes between 1986 and 1992. RESULTS--In 1986, 28% of practices employed a nurse; in 1992, 92% did so. Between 1986 and 1992, 14 cost-rent schemes costing more than 10,000 pounds had been started. Certain practices, designated innovators, were more likely to possess specified items of equipment than other practices. Computer ownership was widespread: 77% of practices had a computer, compared with 36% in 1986. In 1992, 16 practices had a manager, compared with 10 in 1986. Clinic services provided by more than half of practices were well established services (antenatal, for example), new services for which a payment had been introduced (such as diabetes, asthma, minor surgery), or the more readily provided "new" clinic services (diet, smoking cessation). Gross income increased, but so did practice costs, especially for innovators. Practices in the more affluent area of the family health services authority were still more likely to invest in their premises and staff, and to provide more services than those in the declining area. In the more affluent area, practices had higher costs but also higher incomes. CONCLUSION--Between 1986 and 1992, practices in this area invested heavily in equipment and services, but differences remain, depending on the location of the practice. Investment has increased, particularly in the more deprived part of the area, so that the inconsistency in standards has been much reduced. Practice incomes have risen, but so also have workload and costs.     

Also Received

Andreev , A. V. & Kretchmar , A. V. (eds) 1986. Experimental Methods and Results of their Application in Northern Birds Studies. Blondel , J. & Frochot , B. (eds). 1987. Bird Census and Atlas Studies. Chatfield , J. 1987. F. W. Frohawk, his Life and Work. Davidson , I. H. 1986. Birds of Lapalala Wilderness, Waterberg, Transvaal, Southern Birds 13. Dendaletche , C. (ed.) 1987. Oiseaux des Pyrenees (1). Eai .es, T. 1986. Countryman's Memoirs. Edwards , E. P. 1986. A Coded Workbook of the Birds of the World Vol 2. Passerines. Eriksson , M. O. G. (ed.) 1987. Proceedings of the Fifth Nordic Ornithological Congress, 1985, Onsala, Sweden, 5–9 August, 1985. Freethy , R. 1987. Auks: An Ornithologist's Guide. Flegc , J. 1987. The Blue Tit. Ilyichev , V. D. (ed.) 1986. Contemporary Problems of Ornithology. Proc. All-Union Orn. Soc. 1. (Russian.) Instituto de Investigaçao Científica Tropical. 1986. Anuario de Actividades 1986. Kinzelbach , R. & Kasparek , M. (eds) 1986. Zoology in the Middle East. Mees , G. F. 1986. A List of the Birds Recorded from Bangka Island, Indonesia. Muller , Y. 1985. L'Avifaune Forestiere Nicheuse Des Vosges du Nord sa Place dans le Contexte Medio-europeen. National Geographic Society . 1987. Field Guide to the Birds of North America. Roche , J. 1986. Les Oiseaux Nicheurs des Cours d'Eau du Bassin de la Saône. Étude Ecologique des Peuplements le long du Gradient Amont-aval. Snow , D. W. 1987. The Blackbird. Sokolov , V. E. & Dobrvnina , I. N. (eds) 1987. Ringing and Marking of Animals in the Years 1983–1984. Sultanov , F. F. (ed.) 1979. Proc. Acad. Sci. Turkmen. SSR Ser. Biol. Sci. (4). Syroechkovskiy , E. V. (ed.) 1987. Ecology and Migrations of Swans in the USSR. (Russian.) Taylor , M. 1987. The Birds of Sheringham. Tomkies , M. 1987. On Wing and Wild Water. Weaver , P. 1987. The Lapwing. Zwinger , A. 1986. John Xantus, the Fort Tejon Letters 1857–1859.     

The herald waves of influenza virus infections detected in Sendai and Yamagata cities in 1985-1990

The community surveillance of respiratory virus infections performed during 1985-1987 in Sendai and 1988-1990 in Yamagata has identified a total of five herald waves of influenza virus infections: A/H3N2 virus infections in 1985 and 1989, A/H1N1 virus infections in 1986 and 1988, and type B virus infections in 1989. To investigate the antigenic and genetic relationships between the herald wave and epidemic strains, influenza A/H1N1 viruses isolated during the 1986 and 1988 herald waves were compared with those isolated during the 1986-1987 and 1988-1989 epidemic seasons, respectively, utilizing hemagglutination inhibition tests with anti-hemagglutinin monoclonal antibodies and oligonucleotide mapping of total viral RNAs. The results showed that multiple variants differing in antigenic and genetic properties were cocirculating during the 1986 herald wave as well as during each of the two epidemics (only one strain was isolated in the 1988 herald wave). It was also observed that viruses which had the antigenic and/or genetic characteristics closely similar to those of the viruses circulating in the 1986 and 1988 herald waves, were isolated during the winters of 1986-1987 and 1988-1989, respectively.     

Book Reviews

Tyler, S. (Ed.) (1986) Advances in the Biology of Turbellarians and Related Flatyhelmin- thes.
Smol, J.P., Battarbee, R.W., Davis, R.B & Meriläinen, J. (Eds) (1986) Diatoms and Lake Acidity.
Jenkins, D. & Shearer, W.M. (Eds) (1986) The Status of the Atlantic Salmon in Scotland.     

Sarcocystis in American black ducks wintering in New Jersey

Macrocysts of a protozoan parasite, Sarcocystis sp., were found in 28 of 173 American black ducks (Anas rubripes) examined during winters 1984-1985, 1985-1986 and 1986-1987 in south coastal New Jersey (USA). No macrocysts were detected in 80 juvenile black ducks. In adults, the prevalence of macrocysts increased from 3% (1 of 37) in 1984-1985, to 36% (12 of 33) in 1985-1986, and 65% (15 of 23) in 1986-1987. This increase could result in a greater number of harvested birds being discarded, or a change in the attitudes of waterfowl hunters towards black ducks.