三山岛北部海域金矿区水文地质特征分析

通过开展水文地质测绘、水文地质钻探、钻孔综合水文测井及钻孔抽水试验,结合区域地质、水文和气象资料,基本查明了三山岛北部海域金矿区水文地质条件。区内主要含水岩层划分为第四系松散岩类孔隙含水层、花岗岩风化裂隙含水层和构造碎裂岩裂隙含水层,研究表明,矿坑充水直接因素为构造裂隙水,间接因素为风化裂隙水和第四系松散岩类孔隙水。采用比拟法、大井法和水平廊道法对矿坑涌水量进行了预测,除比拟法之外,其余2种方法是根据水文钻孔抽水试验结果计算的,抽水试验严格按照有关规范规程要求进行,试验数据可靠。矿坑涌水量预测结果显示:大井法和水平廊道法计算出的涌水量接近,而比拟法预测结果略微偏大,说明本次预测工作所采用方法和数据较为合理,间接证明渗透参数分析工作是合理的。     

Dynamic Mechanism of Interannual Sea Surface Height Variability in the North Pacific Subtropical Gyre

In this study, the dynamic mechanisms of interannual sea surface height (SSH) variability are investigated based on the first-mode baroclinic Rossby wave model, with a focus on the effects of different levels of wind stress curl (WSC). Maximum covariance analysis (MCA) of WSC and SSH anomalies displays a mode with significant WSC anomalies located primarily in the mid-latitude eastern North Pacific and central tropical Pacific with corresponding SSH anomalies located to the west. This leading mode can be attributed to Ekman pumping induced by local wind stress and the westward-propagating Rossby wave driven by largescale wind stress. It is further found that in the middle latitudes, the SSH anomalies are largely determined by WSC variations associated with the North Pacific Gyre Oscillation (NPGO), rather than the Pacific Decadal Oscillation (PDO). The sensitivity of the predictive skill of the linear first-mode baroclinic model to different wind products is also examined.     

Bacteriophage P4 DNA replication

The suprachiasmatic nucleus (SCN) is the circadian pacemaker in mammals and contains a network of arginine-vasopressin-immunoreactive (AVP-ir) neurons. AVP-recipient cells contain the V1a class of receptors linked to phosphoinositol turnover and protein kinase C (PKC). The present study describes the localization of AVP and the four Ca(2+)-dependent PKC-isoforms in the mouse and rabbit SCN. An estimate of the numerical density of AVP-ir neurons at the rostral, medial, and caudal level of the SCN revealed that the mouse SCN contains more than twice the number of AVP-ir neurons than the rabbit SCN. Neurons immunostained for AVP or PKC dominated in the dorsomedial and ventrolateral aspects of the mouse SCN, while the central area of the SCN revealed only weakly stained neurons. The rabbit SCN was characterized by a more homogeneous distribution of AVP-ir and PKC-ir neurons. PKC alpha was the most abundantly expressed isozyme in both species, whereas the presence of the other isoforms differed (mouse: PKC alpha > PKC beta I > PKC beta II > PKC gamma; rabbit: PKC alpha > PKC beta II > or = PKC gamma > PKC beta I). Clear PKC gamma-positive neurons were only observed in the rabbit SCN, while the mouse SCN predominantly contained immunolabeled fiber tracts for this PKC isozyme. Astrocytes immunoreactive for each PKC isoform were frequently encountered in the rabbit SCN, but were absent in mice. Immunofluorescence double labeling showed that numerous AVP-recipient cells in the mouse SCN were immunopositive for PKC alpha, and that nearly all AVP-ir neurons express PKC alpha abundantly. These results substantiate the putative role for PKC alpha in vasopressinergic signal transduction in the SCN. The differential expression in degree and cell type of the Ca(2+)-dependent PKC-isoforms in the mouse and rabbit SCN may be related to the differences observed in circadian timekeeping between the two species.     

浅析红星山北铅锌矿矿床成因

红星山北铅锌矿位于塔里木板块东北缘天湖裂谷内,矿化体产于大理岩接触带中,受矿区东西向主干断裂带控制,具有层控热液型成矿特征。     

Bacteriophage occurrence in "Mycobacterium phlei" (author's transl)

Surface growth of synchronized bacteria was obtained by means of a suspension of Mycobacterium phlei cells in pentane, the dispersion of which resulted from passage through glass (Ballotini) column. By using standardized conditions, a series of identical cultures were obtained, suitable for studying their evolution as a function of time. By counting colonies every twenty minutes, during ten hours, two doublings were observed, with a generation time of five hours. At the end of a plateau, just before the next doubling, the curve exhibited a marked decrease. Bacteriophages were found in culture medium at the time corresponding to this decrease. In thin sections of the pellicles collected at this time, condensations resembling DNA from phage heads could be noticed within the bacterial cells, as well as free phages in th close neighbourhood of burst cells. The relations between phage and bacteria, and the possible relation between the presence of the phage and the synthesis of phleates has not been determined.     

Bacteriophage MX-1: properties of the phage and its structural proteins

Bacteriophage MX-1 is a virulent DNA phage for Myxococcus. The host range includes strains of Myxococcus xanthus, M. fulvus and M. virescens. The phage has a sedimentation coefficient (S degrees 20,w) of 1145S and a density of 1-531 g/ml. By using SDS-polyacrylamide gel electrophoresis, 23 phage proteins with apparent mol. wt. between 10000 and 150000 were resolved. Gel filtration in the presence of non-ionic detergent partially resolved the proteins. The fraction excluded from Sephadex G-100, fraction 1, contains two glycoproteins. Fraction 1 was resolved into three fractions (1-1, 1-2 and 1-3) by chromatography on Sephadex G-200. The glycoproteins were present in fraction 1-2; all the proteins from this fraction were derived from the phage tail. Comparison of the amino-acid, hexosamine and neutral-sugar compositions of the two glycoproteins showed that they are distinct molecular species; the smaller molecule is not a subunit of the larger. The significance of these findings is discussed and compared with the proteins of the tails of T-even phage of Escherichia coli.     

Use of Percoll gradient centrifugation for the isolation of diatoms from Wadden Sea sediments; diatom yields, species recoveries and population diversity

Platelet-activating factor (PAF) production is carefully controlled in inflammatory cells. The specific removal of arachidonate (AA) from 1-O-alkyl-2-arachidonoyl-sn-glycero-3-phosphocholine (GPC), thought to be mediated by CoA-independent transacylase (CoA-IT), is required to generate the PAF precursor 1-O-alkyl-2-lyso-GPC in human neutrophils. Exposure of A23187-stimulated human monocytes to the CoA-IT inhibitors SK&F 98625 and SK&F 45905 inhibited PAF formation (IC50s of 10 and 12 microM, respectively), indicating that these cells also need CoA-IT activity for PAF production. Because CoA-IT activity transfers arachidonate to a 2-lyso phospholipid substrate, its activity is obligated to an sn-2 acyl hydrolase to form the 2-lyso phospholipid substrate. SB 203347, an inhibitor of 14 kDa phospholipase A2 (PLA2), and AACOCF3, an inhibitor of 85 kDa PLA2, both inhibited AA release from A23187-stimulated human monocytes. However, AACOCF3 had no effect on A23187-induced PAF formation at concentrations as high as 3 microM. Further, depletion of 85 kDa PLA2 using antisense (SB 7111, 1 microM) had no effect on PAF production, indicating a lack of a role of 85 kDa PLA2 in PAF biosynthesis. Both SB 203347 and the 14 kDa PLA2 inhibitor scalaradial blocked PAF synthesis in monocytes (IC50s of 2 and 0.5 microM, respectively), suggesting a key role of 14 kDa PLA2 in this process. Further, A23187-stimulated monocytes produced two forms of PAF: 80% 1-O-alkyl-2-acetyl-GPC and 20% 1-acyl-2-acetyl-GPC, which were both equally inhibited by SB 203347. In contrast, inhibition of CoA-IT using SK&F 45905 (20 microM) had a greater effect on the production of 1-O-alkyl (-80%) than of 1-acyl (-14%) acetylated material. Finally, treatment of U937 cell membranes with exogenous human recombinant (rh) type II 14 kDa PLA2, but not rh 85 kDa PLA2, induced PAF production. Elimination of membrane CoA-IT activity by heat treatment impaired the ability of 14 kDa PLA2 to induce PAF formation. Taken together, these results suggest that a 14 kDa PLA2-like activity, and not 85 kDa PLA2, is coupled to monocyte CoA-IT-induced PAF production.     

Population genetic structure of North Atlantic, Mediterranean Sea and Sea of Cortez fin whales, Balaenoptera physalus (Linnaeus 1758): analysis of mitochondrial and nuclear loci

Samples were collected from 407 fin whales, Balaenoptera physalus, at four North Atlantic and one Mediterranean Sea summer feeding area as well as the Sea of Cortez in the Pacific Ocean. For each sample, the sex, the sequence of the first 288 nucleotides of the mitochondrial (mt) control region and the genotype at six microsatellite loci were determined. A significant degree of divergence was detected at all nuclear and mt loci between North Atlantic/Mediterranean Sea and the Sea of Cortez. However, the divergence time estimated from the mt sequences was substantially lower than the time elapsed since the rise of the Panama Isthmus, suggesting occasional gene flow between the North Pacific and North Atlantic ocean after the separation of the two oceans. Within the North Atlantic and Mediterranean Sea, significant levels of heterogeneity were observed in the mtDNA between the Mediterranean Sea, the eastern (Spain) and the western (the Gulf of Maine and the Gulf of St Lawrence) North Atlantic. Samples collected off West Greenland and Iceland could not be unequivocally assigned to either of the two areas. The homogeneity tests performed using the nuclear data revealed significant levels of divergence only between the Mediterranean Sea and the Gulf of St Lawrence or West Greenland. In conclusion, our results suggest the existence of several recently diverged populations in the North Atlantic and Mediterranean Sea, possibly with some limited gene flow between adjacent populations, a population structure which is consistent with earlier population models proposed by Kellogg, Ingebrigtsen, and Sergeant.     

Cytokine redundancy--unity in diversity

Various cytokines can induce similar biological effects in one type of cells (shared biological activity-redundancy). However, particular cytokine can also act on different tissues and cell types (multiple biological activity-pleiotropy). The functional redundancy and pleiotropy might be explained by binding of related cytokines to a common subunit of the receptor that have unique signalling capacity. Specificity of signal transduction is presumably controlled by the intracytoplasmic structure of the subunit chain, the level of activity of cytoplasmic signal molecules as well as combinations of the receptor subunits on the different type of cells.     

Kinetic diversity in the fusion of exocytotic vesicles

Age is the most important factor for the durability of biological valves. With an original design the Carpentier-Edwards pericardial valve showed improved results at 10 years. The influence of age on valve related complications is studied with a 10 year follow up on 807 valvular replacements. METHODS: Between January 1984 and December 1993, 807 patients underwent valve replacements with a Carpentier-Edwards pericardial bioprosthesis. Patients, 193 were younger than 60 years, 284 between 60 and 70 years and 330 patients were older than 70 years. All patients but seven were followed up for an average of 4.18 years after their operation and total follow up was 3373 patient years. Patients were divided into three groups of age: group I, less than 60 years; group II, 60-70 years; group III, over 70 years. A retrospective comparison was made between age groups. RESULTS: At 11 years, valve related complications included 97 patients with 27 valve related deaths. Rates of valve related death increase with age linearized rate were 0.3, 0.6 and 1.2%, respectively. No difference was observed for rates of all valve related morbidity: 2.6, 2.4 and 3.5%, respectively. Risk of thromboembolism increased with age, linearized rates were: 0.3, 0.7 and 1.3%. Risk of deterioration and reoperation decreased with age, rates of deterioration were 0.8, 0.1 and 0%. Other valve related events had the same incidence in all groups. No statistical difference was observed between group II and group III for deteriorations and reoperations. CONCLUSIONS: The performance of the Carpentier-Edwards pericardial valve is the same at 10 years in group II and III. This study supports the clinical use of this tissue valve in patients over 60 years. The results in group I are satisfactory, nevertheless, a more durable biological valve is needed for young patients.     

Approaching diversity training in the year 2000.

Managing diversity effectively is the most complex human resource challenge of the next century, permeating every aspect of an organization's internal functioning and external marketplace. As organizations continue to contract for diversity consultation and training, expectations for what these programs can offer increase. This article explores the areas that diversity consultation training can successfully address as an intention to meet the organizational challenges to be faced in the next century. A comprehensive model for diversity consultation is proposed to address the multifaceted aspects necessary to build inclusive organizations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)