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71.
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Two subspecies of Orchis ustulata differ considerably in their flowering time, but in only a few morphometric parameters; this makes the rank of these taxa problematic. The flowering time was not affected by replanting individuals to another habitat, including to the habitat of the other subspecies. In this study, populations from both subspecies were studied, measuring 464 marked genets during 5–6 years. Populations with different flowering times exhibited notable differences in their local distribution areas and the mean height of specimens. In the late-flowering populations the proportion of dormant plants is higher and the proportion of vegetatively propagated shoots lower than in the early-flowering ones. Going to (or staying) dormant is the biggest possibility in all stage groups. Flowering is more likely to be followed by dormancy than vegetative stage, but setting fruit does not affect the possibility. Vegetative propagation may play an important role in keeping the populations viable. Vegetative growth is more pronounced on stony soils. 相似文献
73.
Gisela C. Stotz James F. Cahill Jonathan A. Bennett Cameron N. Carlyle Edward W. Bork Diana Askarizadeh Sandor Bartha Carl Beierkuhnlein Bazartseren Boldgiv Leslie Brown Marcelo Cabido Giandiego Campetella Stefano Chelli Ofer Cohen Sandra Díaz Lucas Enrico David Ensing Batdelger Erdenetsetseg Alessandra Fidelis Heath W. Garris Hugh A. L. Henry Anke Jentsch Mohammad Hassan Jouri Kadri Koorem Peter Manning Randall Mitchell Mari Moora Gerhard E. Overbeck Jason Pither Kurt O. Reinhart Marcelo Sternberg Radnaakhand Tungalag Sainbileg Undrakhbold Margaretha van Rooyen Camilla Wellstein Martin Zobel Lauchlan H. Fraser 《Global Ecology and Biogeography》2020,29(3):482-490
74.
Temperate species of Hypomyces and Cladobotryum that produce the red pigment aurofusarin are common on agaricoid and polyporoid basidiomata of species from five orders of Agaricomycetes. Several cause cobweb disease of commercially cultivated mushrooms resulting in serious losses. We sequenced rpb1, rpb2, tef1, and FG1093 regions in 90 wild strains and 30 strains from mushroom farms, isolated from Europe, North America, Africa, Asia, Australia, and New Zealand. Multigene analyses support the distinctness of five species but reveal Hypomyces rosellus to be paraphyletic, comprising several cryptic lineages. Hypomyces rosellus s. str. is characterised by wide dispersal and gene flow across Eurasia but does not occur in North America. Instead, the lineages from the West and the East Coast appear distinct, having given rise to species inhabiting the Southern Hemisphere. Our results reveal wide misuse of the name H. rosellus, especially for cobweb isolates. The majority of these belong to Hypomyces odoratus, including a weakly supported group of fungicide-resistant strains from Europe and North America sharing identical sequence data. New collections are presented for Cladobotryum rubrobrunnescens and Cladobotryum tenue as well as Cladobotryum multiseptatum and Hypomyces dactylarioides, all previously known only from their type material. The former species pair occurs in Europe and the latter in Australia and New Zealand. Separate lineages appear to be maintained by geographic isolation in North America and temperate Australasia but by host specialisation in the species occurring sympatrically in Europe and Asia. Both specialist and generalist host use strategies have evolved in the group. Although teleomorphs are known in most of the species and unnamed lineages, analyses of the five-gene regions suggest the prevalence of clonal reproduction in H. odoratus. This can be the reason for its success in mushroom farms, also facilitating the spread of fungicide resistance. While tef1 and rpb2 can be recommended for species delimitation, low variation, not exceeding 1 % in the whole ingroup, impeaches the use of ITS as a barcoding gene region in this group of fungi. 相似文献
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Abdou Amza Boubacar Kadri Baido Nassirou Sun N. Yu Nicole E. Stoller Satasuk J. Bhosai Zhaoxia Zhou Charles E. McCulloch Sheila K. West Robin L. Bailey Jeremy D. Keenan Thomas M. Lietman Bruce D. Gaynor 《PLoS neglected tropical diseases》2013,7(1)
Background
Control programs for trachoma use mass antibiotic distributions to treat ocular Chlamydia trachomatis in an effort to eliminate this disease worldwide. To determine whether children infected with ocular Chlamydia are more likely to present later for examination than those who are uninfected, we compare the order of presentation for examination of children 0–5 years, and the presence of ocular Chlamydia by PCR in 4 villages in Niger where trachoma is endemic.Methods
We conducted a cluster-randomized, controlled trial where 48 randomly selected villages in Niger are divided into 4 study arms of different mass treatment strategies. In a substudy of the main trial, we randomly selected 1 village from each of the 4 study arms (4 total villages) and we evaluated the odds of ocular Chlamydia versus the rank order of presentation for examination and laboratory assessment before treatment was offered.Findings
We found the odds of harboring ocular Chlamydia dropped by more than 70% from the first child examined to the last child examined (OR 0.27, 95% CI 0.13–0.59, P = 0.001) in the 4 randomly selected villages. We found the odds of active trachoma dropped by 80% from the first child examined to the last child examined (OR 0.20, 95% CI 0.10–0.4, P<0.0001) in the 48 villages in the main trial.Interpretation
This study demonstrates that even if the WHO recommended 80% treatment coverage is not reached in certain settings, children 0–5 years with the greatest probability of ocular Chlamydia have higher odds of receiving attention because they are the first to present. These results suggest there may be diminishing returns when using scarce resources to track down the last few children in a mass treatment program.Trial Registration
ClinicalTrials.gov NCT00792922相似文献77.
Tedersoo L Naadel T Bahram M Pritsch K Buegger F Leal M Kõljalg U Põldmaa K 《The New phytologist》2012,195(4):832-843
? Ectomycorrhizal (ECM) fungi obtain both mineral and simple organic nutrients from soil and transport these to plant roots. Natural abundance of stable isotopes ((15) N and (13) C) in fruit bodies and potential enzymatic activities of ECM root tips provide insights into mineral nutrition of these mutualistic partners. ? By combining rDNA sequence analysis with enzymatic and stable isotope assays of root tips, we hypothesized that phylogenetic affinities of ECM fungi are more important than ECM exploration type, soil horizon and host plant in explaining the differences in mineral nutrition of trees in an African lowland rainforest. ? Ectomycorrhizal fungal species belonging to extraradical mycelium-rich morphotypes generally displayed the strongest potential activities of degradation enzymes, except for laccase. The signature of (15) N was determined by the ECM fungal lineage, but not by the exploration type. ? Potential enzymatic activities of root tips were unrelated to (15) N signature of ECM root tip. The lack of correlation suggests that these methods address different aspects in plant nutrient uptake. Stable isotope analysis of root tips could provide an additional indirect assessment of fungal and plant nutrition that enables enhancement of taxonomic coverage and control for soil depth and internal nitrogen cycling in fungal tissues. 相似文献
78.
CD4(+) type II NKT cells mediate ICOS and programmed death-1-dependent regulation of type 1 diabetes
Kadri N Korpos E Gupta S Briet C Löfbom L Yagita H Lehuen A Boitard C Holmberg D Sorokin L Cardell SL 《Journal of immunology (Baltimore, Md. : 1950)》2012,188(7):3138-3149
Type 1 diabetes (T1D) is a chronic autoimmune disease that results from T cell-mediated destruction of pancreatic β cells. CD1d-restricted NKT lymphocytes have the ability to regulate immunity, including autoimmunity. We previously demonstrated that CD1d-restricted type II NKT cells, which carry diverse TCRs, prevented T1D in the NOD mouse model for the human disease. In this study, we show that CD4(+) 24αβ type II NKT cells, but not CD4/CD8 double-negative NKT cells, were sufficient to downregulate diabetogenic CD4(+) BDC2.5 NOD T cells in adoptive transfer experiments. CD4(+) 24αβ NKT cells exhibited a memory phenotype including high ICOS expression, increased cytokine production, and limited display of NK cell markers, compared with double-negative 24αβ NKT cells. Blocking of ICOS or the programmed death-1/programmed death ligand 1 pathway was shown to abolish the regulation that occurred in the pancreas draining lymph nodes. To our knowledge, these results provide for the first time cellular and molecular information on how type II CD1d-restricted NKT cells regulate T1D. 相似文献
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