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71.
RECOVERY FROM DORMANCY IN ROOTS 总被引:15,自引:12,他引:3
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THE CYANOPHYTE-HEPATIC SYMBIOSIS I. MORPHOLOGY AND PHYSIOLOGY 总被引:6,自引:5,他引:1
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T. A. F. LONG P. M. MILLER A. D. STEWART W. R. RICE 《Journal of evolutionary biology》2009,22(3):637-643
The heritability of genome‐wide fitness that is expected in finite populations is poorly understood, both theoretically and empirically, despite its relevance to many fundamental concepts in evolutionary biology. In this study, we used two independent methods of estimating the heritability of lifetime female fecundity (the predominant female fitness component in this population) in a large, outbred population of Drosophila melanogaster that had adapted to the laboratory environment for over 400 generations. Despite strong directional selection on adult female fecundity, we uncovered high heritability for this trait that cannot be explained by antagonistic pleiotropy with juvenile fitness. The evolutionary significance of this high heritability of lifetime fecundity is discussed. 相似文献
78.
GAVIN GOUWS BARBARA A. STEWART SAVEL R. DANIELS 《Biological journal of the Linnean Society. Linnean Society of London》2010,101(2):385-402
The gilgie (Cherax quinquecarinatus) is among the more widespread of the six endemic south‐western Australian freshwater crayfish species. In the present study, the phylogeographic structure of the gilgie was investigated across its distribution to determine whether patterns reflected those identified earlier in a co‐distributed congeneric, the koonac (Cherax preissii). Gilgies were sampled from 20 localities, a 412‐bp fragment of the cytochrome c oxidase subunit I mitochondrial DNA gene was amplified from 75 individuals, and allozyme variation was assayed at nine loci. As in the koonac, three geographically‐restricted lineages were identified: from the north‐western, southern coastal, and intermediate/south‐western regions. Phylogeographic breaks appeared to be congruent with those in the koonac. The extent of genetic differentiation among lineages was comparable to that in the koonac, suggesting temporal congruence of the historical events responsible for the observed structure. A relaxed Bayesian molecular clock suggested that the major clades and lineages in each species diverged in the Late Miocene–Early Pliocene (4.0–9.6 Myr ago), possibly resulting from increasing pulses of aridity. The retrieval of almost‐identical phylogeographic structure in two co‐distributed species suggests that biogeographic regions can be more accurately defined in south‐western Australia. With the geographic fidelity of these lineages, the present data also provide evidence of the translocation of a single individual from the north‐west to the south coast. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 385–402. 相似文献
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YO TOMA FABIÁN G. FERNÁNDEZ AYA NISHIWAKI TOSHIHIKO YAMADA GERMÁN BOLLERO J. RYAN STEWART 《Global Change Biology Bioenergy》2010,2(2):52-62
Although fire has been used for several thousand years to maintain Miscanthus sinensis grasslands in Japan, there is little information about the nutrient dynamics in these ecosystems immediately after burning. We investigated the loss of aboveground biomass; carbon (C) and nitrogen (N) dynamics; surface soil C change before and after burning; and carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) fluxes 2 h after burning in a M. sinensis grassland in Kumamoto, Japan. We calculated average C and N accumulation rates within the soil profile over the past 7300 years, which were 58.0 kg C ha?1 yr?1 and 2.60 kg N ha?1 yr?1, respectively. After burning, 98% of aboveground biomass and litter were consumed. Carbon remaining on the field, however, was 102 kg C ha?1. We found at least 43% of C was possibly lost due to decomposition. However, remaining C, which contained ash and charcoal, appeared to contribute to C accumulation in soil. There was no difference in the amount of 0–5 cm surface soil C before and after burning. The amount of remaining litter on the soil surface indicated burning appeared not to have caused a reduction in soil C nor did it negatively impact the sub‐surface vegetative crown of M. sinensis. Also, nearly 50 kg N ha?1 of total aboveground biomass and litter N was lost due to burning. Compared with before the burning event, postburning CO2 and CH4 fluxes from soil appeared not to be directly affected by burning. However, it appears the short time span of measurements of N2O flux after burning sufficiently characterized the pattern of increasing N2O fluxes immediately after burning. These findings indicate burning did not cause significant reductions in soil C nor did it result in elevated CO2 and CH4 emissions from the soil relative to before the burning event. 相似文献
80.
stewart c. j. r. and kennedy j. h. (1998) Cytopathology 9, 38–45
Peritoneal fluid cytology in serous borderline tumours of the ovary
Peritoneal fluid cytology findings in three patients with serous borderline tumours of the ovary and peritoneal serous implants are presented. The specimens were characterized by papillary groups, acinar clusters and single neoplastic cells exhibiting cytoplasmic vacuolation and nuclear atypia of variable degree. The cytological appearances were initially considered consistent with ovarian adenocarcinoma in all cases. Histological correlation is required to avoid this diagnostic pitfall. 相似文献
Peritoneal fluid cytology in serous borderline tumours of the ovary
Peritoneal fluid cytology findings in three patients with serous borderline tumours of the ovary and peritoneal serous implants are presented. The specimens were characterized by papillary groups, acinar clusters and single neoplastic cells exhibiting cytoplasmic vacuolation and nuclear atypia of variable degree. The cytological appearances were initially considered consistent with ovarian adenocarcinoma in all cases. Histological correlation is required to avoid this diagnostic pitfall. 相似文献