共查询到20条相似文献,搜索用时 15 毫秒
1.
Ralph L. Holloway 《American journal of physical anthropology》1981,55(4):503-521
New brain endocast reconstructions of Homo erectus discoveries from Indonesia since 1963 (H. erectus VI, 1963; VII, 1965; VIII, 1969) have been made and their volumes determined. In addition, older discoveries (H. erectus I, 1891; II, 1937; IV, 1937–38) have been reendocast and reconstructed, and have yielded volumes considerably different from those previously published. This is particularly so in the case of Dubois's original discovery, which yields a volume of 940 ml rather than the widely quoted volume of 750 ml. In addition, a number of morphological observations regarding hemispheric asymmetries (petalias) are provided, which suggest a condition similar to modern Homo sapiens. 相似文献
2.
Palmen J Smith AJ Dorfmeister B Putt W Humphries SE Talmud PJ 《Biochimica et biophysica acta》2008,1782(7-8):447-452
3.
Sharp J 《Biologist (London, England)》2002,49(4):179
Mary Kingsley was an archetype, if not the archetype, of the formidable Victorian lady. Despite her physical frailty she managed to face the most hair-raising encounters in remote West Africa with an unshakeable aplomb that almost defies belief. She also made a number of not inconsiderable contributions to biology. 相似文献
4.
Borax methylene blue is quite stable at room temperatures of 22-25 C. At 30 C polychroming is slow; during 50 days in a water bath at this temperature the absorption peak moves from 665 to 656 nm. At 35 C, the absorption peak reaches 660 nm in 7 days, 654 nm in 14. At 60 C polychroming is rapid, the absorption peak reaching 640-620 nm in 3 days. When the pH of the borax methylene blue solutions, normally about 9.0, is adjusted to pH 6.5, the absorption peak remains at 665 nm even when incubated at 60 C for extended periods. When used as a blood stain 0.4 ml borax methylene blue (1% methylene blue in 1% borax), 4 ml acetone, 2 ml borax-acid phosphate buffer to bring the solution to pH 6.5, and distilled water to make 40 ml, with 0.2 ml 1% eosin added just before using, an excellent Nocht-Giemsa type stain is achieved after 30 minutes staining. The material plasmodia P. falciparum, P. vivax, and P. berghei stain moderate blue with dark red chromatin and green to black pigment granules. The study confirms Malachowski's 1891 results and explains Gautier's 1896-98 failure to duplicate it. 相似文献
5.
This study explores the impact an exogenous improvement in childhood health has on later-life outcomes. Using extensive and detailed register data from the Swedish Interdisciplinary Panel covering up to 2011, we follow individuals exposed to the introduction of the first vaccine against polio in Sweden (birth cohorts 1937–1966) until adulthood in order to quantify the causal effect of polio vaccination on long-term economic outcomes. The results show that, contrary to what has been found in the literature for other health-related interventions, including other vaccines, exposure to the vaccine against polio did not seem to have any long-term effects on the studied adult economic outcomes. Upon closer inspection of how the disease affects children, this might be explained by the fact that no scarring effects from exposure to high incidence of polio were found on adult income, educational achievement, or hospitalizations, which seems to suggest that those who contracted the illness but suffered only the milder symptoms of the disease made a full recovery and had no lifelong sequels as a consequence of the condition. The absence of scarring effects is hypothesized to be related to the pathology and epidemiology of the disease itself, which infects many, but scars only those who suffer the most recognizable paralytic symptoms. 相似文献
6.
Acute hepatopancreatic necrosis disease (AHPND) outbreaks in cultured shrimps were identified in Zhangpu, China. One Vibrio parahaemolyticus strain PB1937 was isolated from the cultured shrimps and was confirmed as a causative agent of the AHPND outbreak by employing Koch’s four postulates. Challenge tests with 106 cells ml?1 of strain PB1937 caused 100% mortality of shrimps, indicating it had sufficient virulence to cause the outbreak. Phylogenomic analysis revealed a clear divergence between PB1937 and 14 publicly available V. parahaemolyticus strains and divided 11 AHPND-causing strains into six genomic clusters. Prophage profiling of above strains revealed strong correlations with their genomic relationship, while Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) were almost absent in the genomes. The binary toxin gene pirABvp directly related to the development of AHPND was found in a 70-kb plasmid p1937-1 in PB1937 but was absent in a 78-kb novel plasmid p1937-2, which shared 46% sequence similarity with p1937-1. Comparative genomic analysis revealed that PB1937 has a novel truncated type VI secretion system (T6SS1) which possibly affects its antibacterial activity. In addition, three novel genomic islands were reported. The analysis of the genomes gave some clues regarding the correlation of virulence with its genomic trait for the AHPND strains. 相似文献
7.
Voitto Haukisalmi Sauli Laaksonen Antti Oksanen Kimberlee Beckmen Ali Halajian Tetsuya Yanagida Minoru Nakao 《Parasitology international》2018,67(2):218-224
Phylogenetic relationships of tapeworms of the genus Moniezia Blanchard, 1891 (Cestoda, Anoplocephalidae) parasitizing the Eurasian elk Alces alces, the moose A. americanus and the reindeer/caribou Rangifer tarandus (Cervidae) were studied using DNA sequences of two mitochondrial genes (cox1 and nad1). Several isolates from domestic ruminants, representing Moniezia expansa (Rudolphi, 1810) sensu lato and M. benedeni (Moniez, 1879) sensu lato, and one unidentified isolate from an African antelope, were also included in the analysis.Both genes identified the same six species of Moniezia, but interspecific phylogenetic relationships were better resolved by the nad1 data. The six species of Moniezia comprised two main clades: clade 1 that originates in bovids, with subsequent colonization of northern cervids in Eurasia, and clade 2 that originates in northern cervids, with subsequent specific divergence within these hosts. Clade 2 has a Holarctic distribution.None of the Moniezia specimens in Alces and Rangifer was conspecific with the species in domestic ruminants, suggesting that the custom of identifying Moniezia spp. in northern cervids either as M. expansa or M. benedeni is incorrect. At least two of the species parasitizing Alces and Rangifer have not been previously recognized. These findings challenge the results of all previous studies concerning the diversity and ecology of Moniezia spp. in northern cervids.The traditional classification into three subgenera (Moniezia Blanchard, 1891, Blanchariezia Skrjabin & Schultz, 1937 and Baeriezia Skrjabin & Schultz, 1937), based on the presence and type of interproglottidal glands, conflicts with the currently observed molecular phylogenetic relationships within the genus Moniezia. 相似文献
8.
Howard Gest 《Photosynthesis research》1991,30(1):49-59
Hans Molisch (1856–1937) was an exceptionally gifted and productive researcher who had broad interests in plant biology, physiology and biochemistry. In addition, he pioneered in isolating a number of species of purple photosynthetic bacteria in pure culture (including Rhodobacter capsulatus), which facilitated his discovery of basic aspects of bacterial photosynthesis. Molisch demonstrated conclusively that molecular oxygen is not produced by photosynthetic bacteria, and discovered the photoheterotrophic growth mode. The range of Molisch's research accomplishments was impressive, and he emerges as a major figure in the history of photosynthesis research. This essay reviews the numerous research contributions made by Molisch, particularly in regard to advancing knowledge of the several forms of photosynthetic metabolism. An English translation of his 1914 paper on the photosynthetic creation of visual images on leaves is included as an Appendix. 相似文献
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10.
Piers J. Hale 《Journal of the history of biology》2013,46(4):551-597
The nineteenth century theologian, author and poet Charles Kingsley was a notable populariser of Darwinian evolution. He championed Darwin’s cause and that of honesty in science for more than a decade from 1859 to 1871. Kingsley’s interpretation of evolution shaped his theology, his politics and his views on race. The relationship between men and apes set the context for Kingsley’s consideration of these issues. Having defended Darwin for a decade in 1871 Kingsley was dismayed to read Darwin’s account of the evolution of morals in Descent of Man. He subsequently distanced himself from Darwin’s conclusions even though he remained an ardent evolutionist until his death in 1875. 相似文献
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12.
二十世纪中叶以后,中、美寒武纪地层研究都有重大进展。三叶虫是寒武纪的重要化石,中、晚寒武世牙形石有显著的生物地层意义。二十世纪中叶国内研究寒武系的学者,认为北美寒武系与西欧及北欧的相似,与中国的差异较大。目前看来,北美东部斜坡相区的寒武系与西欧、北欧相似外,北美西部广大地区(包括阿拉斯加、加拿大及美国境内的落基山等地区),分别与西伯利亚,蒙古西北部一些地区,及我国华北、东北南部及华南等地区的寒武系关系较近。北美西部Nevada及Utah等地也显示地台区及斜坡相区的不同。文内对两个地区早、中、晚寒武世地层内相同的属或种,分别进行对比。两地区属种相同的数目,由老到新逐渐增多。岩石方面,也有相似之处,如Pioche页岩和馒头组的岩性,Notch Peak灰岩与凤山组藻类灰岩及Hales灰岩与华北晚寒武世的竹叶状灰岩等,都有相似之处。 相似文献
13.
German A. Kochetov Olga N. Solovjeva 《Biochimica et Biophysica Acta - Proteins and Proteomics》2014,1844(9):1608-1618
Studies of thiamine diphosphate-dependent enzymes appear to have commenced in 1937, with the isolation of the coenzyme of yeast pyruvate decarboxylase, which was demonstrated to be a diphosphoric ester of thiamine. For quite a long time, these studies were largely focused on enzymes decarboxylating α-keto acids, such as pyruvate decarboxylase and pyruvate dehydrogenase complexes. Transketolase, discovered independently by Racker and Horecker in 1953 (and named by Racker) [1], did not receive much attention until 1992, when crystal X-ray structure analysis of the enzyme from Saccharomyces cerevisiae was performed [2]. These data, together with the results of site-directed mutagenesis, made it possible to understand in detail the mechanism of thiamine diphosphate-dependent catalysis. Some progress was also made in studies of the functional properties of transketolase. The last review on transketolase, which was fairly complete, appeared in 1998 [3]. Therefore, the publication of this paper should not seem premature. 相似文献
14.
织纹螺属两个混淆种的比较研究 总被引:2,自引:2,他引:0
论述了2个混淆种扩张织纹螺Nassarius(Telasco)sufflatus(Gould,1860)与爪哇织纹螺Nassarius(Telasco)javanus(Schepman,1891)的比较研究,二者在我国均分布于的东南部沿海,其外部形态近似。长期以来,一直把2个种混淆在一起,都鉴定为扩张织纹螺。作者在整理中国科学院海洋生物标本馆历年来采集的织纹螺科标本时,把2个种的标本进行了反复的比较研究,并进行齿舌解剖,找出了二者外部形态、齿舌结构以及地理分布和生态习性上的差异,澄清了混淆种,确立其分类地位。 相似文献
15.
Helmut Sick 《Journal of Ornithology》1962,103(1):102-107
Summary The Painted Snipe,Nycticryphes semicollaris, which up till now had only once (1891) been located with certainty in Brazil, was found by the author in May 1961 on the Lagoa Feia, State of Rio de Janeiro. Ten specimens were collected five of which were adults in their reproductive period. There does not appear to be any special difference between the sexes as to coloring and size. Immature is succeded by subadult plumage. Two other southern species were found in the same region: the Variegated Bittern,Ixobrychus involucris, and the Black-faced Spinetail,Phleocryptes melanops.
相似文献
16.
The frequency and cost of referrals to specialists in March 1984 for 8980 rostered patients attending a family practice clinic located in a teaching hospital were analysed. The patients made 1891 visits to specialists. In all age groups and for all specialties female patients were more likely to be seen. The total direct provider costs were higher for female patients than for male patients. However, costs per patient seen were higher for male patients, except for psychiatry and medicine. Visits to surgeons had the highest total cost, while visits to psychiatrists had the highest cost per patient seen. Of the direct provider costs 61% was for specialist services. The family physician, in the “gatekeeper” role, has an opportunity to control some of the costs of the health care system by ensuring that the best and most efficient use is made of the referral network. 相似文献
17.
Malcolm J Morrison 《Génome》2008,51(6):465-469
Charles Edward Saunders was born in London, Ontario, in 1867. His father, Sir William Saunders, was the first director of the Dominion Experimental Farms (1886-1911). Charles received his B.A. with honours in science from the University of Toronto in 1888 and his Ph.D. in chemistry from Johns Hopkins University in Baltimore, Maryland, in 1891. He attempted a career in music, his first love, from 1893 to 1902. With his father, Charles attended the 1902 International Conference on Plant Breeding and Hybridization in New York, where he learned of Mendel's theories of inheritance and their applicability to plant breeding. When he began work in 1903 in the Division of Cereal Breeding and Experimentation at the Central Experimental Farm in Ottawa, he used the knowledge he had gained at that conference. It was Charles's goal to achieve "fixity" in the varieties that had been bred and released using phenotypic mass selection, prior to his tenure as Cerealist. He selected four heads from the wheat variety Markham and in the winter of 1904 he performed a "chewing test" to select for gluten elasticity and colour. Seeds from two heads were chosen, and seeds from one went on to produce the variety Marquis after extensive yield trials on the Prairies. Marquis was 7 to 10 days earlier than Red Fife, the standard bread wheat of the Prairies. The earliness and tremendous yield of Marquis wheat resulted in the rapid and successful settlement of the Great Plains and countless billions of dollars in revenue to Canada. By 1923, 90% of the spring wheat in Canada and 70% in the USA was Marquis. Charles continued as Dominion Cerealist until his retirement in 1922. He was knighted in 1934, and died in 1937. 相似文献
18.
Kibeom Lee Jeewon Lee Yang-Hoon Kim Seung-Hyeon Moon Young-Hoon Park 《Current microbiology》2001,43(6):383-390
With four Lactobacilli--L. delbrueckii subsp. lactis (ATCC 12315), L. casei (NRRL-B1445), L. delbrueckii (NRRL-B445), and L. heveticus (NRRL-B1937)--the characteristics of cell growth and production of lactate and amino acids were investigated. Especially, the time-course variation in concentration of amino acids (classified into alanine, serine, aspartate, glutamate, aromatic amino acid, and histidine families) was estimated in detail, and the results were systematically compared. It was elucidated that L. delbrueckii (NRRL-B445) and L. helveticus (NRRL-B1937) had quite different characteristics in growth, lactic acid synthesis, and amino acid production. L. helveticus (NRRL-B1937) was superior in the production of amino acids as well as in cell growth, but showed very poor ability in lactic acid production. However, L. delbrueckii (NRRL-B445) showed higher yield of lactic acid despite repressed cell growth, but suffered from severe amino acid deficiency in culture. By modulating the initial concentration of each strain in the mixed culture containing both L. delbrueckii (NRRL-B445) and L. helveticus (NRRL-B1937), the lactic acid production (i.e., the amount of lactic acid produced and lactic acid yield to glucose consumed) was significantly improved, presumably via symbiotic interaction between the two strains. 相似文献
19.
The relative importance of sexual reproduction versus clonal spread in an aridland bunchgrass 总被引:5,自引:0,他引:5
Festuca idahoensis (Idaho fescue) is a perennial caespitose grass, common in semi-arid rangelands of the Intermountain West. To determine how individuals are recruited into a population, we studied two long-term monitoring plots that were established in 1937 at the Northern Great Basin Experimental Range in southeastern Oregon. The plots measured 3.05×3.05 m, and were located approximately 30 m apart. One plot was ungrazed, the other was subject to moderate levels of cattle grazing. The number of F. idahoensis plants in both plots increased ten-fold between 1937 and 1996, but whether this was due primarily to reproduction by seed or clonal fragmentation was unknown. In 1996, we mapped and sampled 160 plants of F. idahoensis. We used dominant inter-simple sequence repeat (ISSR) markers and codominant allozyme markers in order to identify genetic individuals and measure genetic diversity. Both plots were characterized by high levels of genetic and clonal diversity. When information from ISSRs, allozymes and sample location were combined, 126 genets were recognized, each consisting of one to four samples (ramets). By measuring the diameter of clones surrounding plants that were present in 1937, we estimated that clonal spread occurred at a rate of approximately 3.7 cm per decade, and thus was of secondary importance in the maintenance and increase of F. idahoensis stands. Sexual reproduction, rather than clonal fragmentation, accounted for most of the recruitment of new plants into these plots. The grazed plot had fewer ramets, genotypes, and clones than the ungrazed plot, but the ramets were significantly larger. Levels of genetic diversity did not differ in the grazed and ungrazed plots, but there was some evidence for a small, but significant level of genetic differentiation between the two. The results also indicate that F. idahoensis has the potential to be a long-lived species with some individuals persisting in excess of 60 years. This study demonstrates how long-term monitoring can be supplemented by genetic analysis to obtain detailed information on the population dynamics of plants. In the case of this community dominant species, this provides essential information for understanding succession and developing management and restoration strategies.Electronic Supplementary Material Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s00442-003-1332-2 相似文献
20.
High-pressure inactivation of hepatitis A virus within oysters 总被引:3,自引:0,他引:3
Previous results demonstrated that hepatitis A virus (HAV) could be inactivated by high hydrostatic pressure (HHP) (D. H. Kingsley, D. Hoover, E. Papafragkou, and G. P. Richards, J. Food Prot. 65:1605-1609, 2002); however, direct evaluation of HAV inactivation within contaminated oysters was not performed. In this study, we report confirmation that HAV within contaminated shellfish is inactivated by HHP. Shellfish were initially contaminated with HAV by using a flowthrough system. PFU reductions of >1, >2, and >3 log(10) were observed for 1-min treatments at 350, 375, and 400 megapascals, respectively, within a temperature range of 8.7 to 10.3 degrees C. Bioconcentration of nearly 6 log(10) PFU of HAV per oyster was achieved under simulated natural conditions. These results suggest that HHP treatment of raw shellfish will be a viable strategy for the reduction of infectious HAV. 相似文献