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101.
102.
Cynara C. T. Romero Jasper P. Vermeulen Anton Vels Axel Himmelbach Martin Mascher Rients E. Niks 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2018,131(5):1031-1045
Key message
Resistance factors against non-adapted powdery mildews were mapped in barley. Some QTLs seem effective only to non-adapted mildews, while others also play a role in defense against the adapted form.The durability and effectiveness of nonhost resistance suggests promising practical applications for crop breeding, relying upon elucidation of key aspects of this type of resistance. We investigated which genetic factors determine the nonhost status of barley (Hordeum vulgare L.) to powdery mildews (Blumeria graminis). We set out to verify whether genes involved in nonhost resistance have a wide effectiveness spectrum, and whether nonhost resistance genes confer resistance to the barley adapted powdery mildew. Two barley lines, SusBgtSC and SusBgtDC, with some susceptibility to the wheat powdery mildew B. graminis f.sp. tritici (Bgt) were crossed with cv Vada to generate two mapping populations. Each population was assessed for level of infection against four B. graminis ff.spp, and QTL mapping analyses were performed. Our results demonstrate polygenic inheritance for nonhost resistance, with some QTLs effective only to non-adapted mildews, while others play a role against adapted and non-adapted forms. Histology analyses of nonhost interaction show that most penetration attempts are stopped in association with papillae, and also suggest independent layers of defence at haustorium establishment and conidiophore formation. Nonhost resistance of barley to powdery mildew relies mostly on non-hypersensitive mechanisms. A large-effect nonhost resistance QTL mapped to a 1.4 cM interval is suitable for map-based cloning.103.
K. S. Jasper Kanes Stan E. Dosso Tania Lado Insua Xavier Mouy Andrew Bateman 《Marine Mammal Science》2024,40(1):73-88
Evaluation of temporal patterns in offshore marine mammal activity through visual data collection can be impaired by light and weather conditions and the cost of ship time. The conditions-independence and cost-efficacy of acoustic data collection make it popular for researching the temporal patterns of wild dolphins. However, Pacific white-sided dolphins (PWSDs) north of Southern California remain under-researched. This study evaluates diel and seasonal patterns in PWSD communication signals detected in 480 days of near-continuous passive acoustic data collected over 20 months from the Barkley Canyon node of Ocean Networks Canada's NEPTUNE observatory, offshore Vancouver Island, British Columbia, Canada. In this study, a random forest classifier is used to identify PWSD pulsed calls and false positives are manually removed. The resulting acoustic presence-absence data set is evaluated for seasonal and diel patterns using generalized additive mixed models, considering masking effects from ambient noise. PWSDs are found to be vocally active during all diel periods year-round, with high summer and low spring activity. Seasonally dependent diel patterns are identified, with PWSD pulsed calls exhibiting no diel pattern in spring, a slight increase in vocal activity during dusk and night in fall and winter, and a notable increase during night and dawn in summer. 相似文献
104.
Christoph Korte Torsten Jasper Ján Veizer 《Palaeogeography, Palaeoclimatology, Palaeoecology》2005,224(4):333-351
Two hundred sixty-four δ18O and δ13C values of Permian articulate brachiopod shells were analyzed and 81 of these values were characterized as well preserved and biostratigraphically well defined. These were then utilized for construction of baseline oxygen and carbon isotope curves for the Permian interval. In addition, 21 δ13C whole rock values are reported for the Wordian and Capitanian.The early Permian, Asselian to Artinskian, times are characterized by ∼ 2.5‰ decrease in oxygen isotope values, from ∼ − 0.7‰ to − 3.3‰ (V-PDB). This is attributed to a ∼ 4-7 °C increase in temperature in the Southern Urals, concomitant with the retreat of the Permo-Carboniferous ice sheets and return of the 18O-depleted melt water into the oceans. The Late Permian samples from Iran (Jolfa at Kuh-e-Ali-Bashi) and China (Meishan) yield δ18O values, and presumably temperatures, similar to those that followed the termination of the large-scale glaciation in the Lower Permian. In between, the upper Kungurian to Capitanian samples from the Delaware Basin (Guadalupe Mountains) are enriched in 18O, at − 1.5‰ to − 3‰. We have no definitive explanation for these data, but tentatively suggest that the “anomaly” can potentially be a result of evaporative enrichment of seawater in 18O, due to intracratonic arid setting of the basin. The 18O-enriched nature of the Zechstein samples (− 1.2‰ to + 2.5‰), on the other hand, is in all probability a reflection of the high evaporation rates in the Zechstein sea.The Permian interval is characterized by a relatively constant δ13C, at about 4‰. The exceptions are again the brachiopods from the Delaware Basin (Guadalupe Mountains), which show ∼ 1.6‰ increase in the Guadalupian, to values of up to 5.9‰ in the Wordian. A tentative explanation, as in the case of oxygen, is based on the proposition that the semi-enclosed Delaware Basin was likely stratified, with sequestration of the 13C-depleted carbon to the deeper water layers and a complementary 13C enrichment in the upper oxygenated layer. The coeval open ocean water DIC may have been similar to that of the remainder of the Permian interval, at ∼ 4‰, as indicated by whole rock carbonate samples from Oman, Sicily, and Iran. In the latest Permian, the trend mimics the well-known δ13C drop at the Permian/Triassic boundary. 相似文献
105.
Zwinderman AH Glas AS Bossuyt PM Florie J Bipat S Stoker J 《Biostatistics (Oxford, England)》2008,9(3):513-522
We propose random-effects models to summarize and quantify the accuracy of the diagnosis of multiple lesions on a single image without assuming independence between lesions. The number of false-positive lesions was assumed to be distributed as a Poisson mixture, and the proportion of true-positive lesions was assumed to be distributed as a binomial mixture. We considered univariate and bivariate, both parametric and nonparametric mixture models. We applied our tools to simulated data and data of a study assessing diagnostic accuracy of virtual colonography with computed tomography in 200 patients suspected of having one or more polyps. 相似文献
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108.
Sod cutting (i.e. top soil removal) is a restoration management option for enhancing seedling establishment and for lowering the nutrient concentration in eutrophicated soils of nutrient-poor species-rich grasslands. Removal of the upper soil changes not only abiotic soil properties but may also affect the resident soil community. We investigated the effects of sod cutting on the establishment and performance of two endangered plant species (Cirsium dissectum and Succisa pratensis) while simultaneously manipulating the interaction between seedlings and soil biota. In intact grassland and sod-cut areas at two localities, seedlings were grown in plastic tubes. Half of the tubes had a filter that excluded roots but allowed entry of fungal hyphae and soil microorganisms. The other tubes were closed (i.e. no contact with the surrounding soil). In a greenhouse experiment we studied the effect of soil solutions (with or without fungal tissue) from three grasslands and three sod-cut areas on seedling growth. Sod cutting had a positive net effect on seedling growth for S. pratensis. Access to (mycorrhizal) fungi and other soil biota resulted in a negative impact on seedling growth of both plant species, both in grassland and sod-cut areas. The greenhouse experiment confirmed that the soil biota in these meadows reduced seedling growth. Although sod cutting did not mitigate negative plant-soil feedback, it enhanced seedling growth, presumably by decreasing competition for light. Sod cutting is therefore very useful when seedling establishment needs to be stimulated. 相似文献
109.
Jasper B. Green Ryan P. J. Lower J. Peter W. Young 《Journal of molecular evolution》2009,69(6):657-667
NfeD-like proteins are widely distributed throughout prokaryotes and are frequently associated with genes encoding stomatin-like
proteins (slipins). Here, we reveal that the NfeD family is ancient and comprises three major groups: NfeD1a, NfeD1b and truncated
NfeD1b. Members of each group are associated with one of four conserved gene partners, three of which have eukaryotic homologues
that are membrane raft associated, namely stomatin, paraslipin (previously SLP-2) and flotillin. The first NfeD group (NfeD1b),
comprises proteins of approximately 460-aa long that have three functional domains: an N-terminal protease, a middle membrane-spanning
region and a soluble C-terminal region rich in β-strands. The nfeD1b gene is adjacent to eoslipin in prokaryotic genomes except in Firmicutes and Deinococci, where yqfA replaces eoslipin. Proteins in the second major group (NfeD1a) are homologous to the C-terminus of NfeD1b which forms a β-barrel-like domain,
and their genes are associated with paraslipin. Using OrthoMCL clustering, we show that nfeD1b genes have become truncated on many independent occasions giving rise to the third major group. These short NfeD homologues
frequently remain associated with their ancestral gene neighbour, resembling NfeD1a in structure, yet are much more related
to full-length NfeD1b; we term these “truncated NfeD1b”. These conserved associations suggest that NfeD proteins are dependent
on gene partners for their function and that the site of interaction may lie within the C-terminal portion that is common
to all NfeD homologues. Although NfeD homologues are confined to prokaryotes, this conserved association could represent an
excellent system to study slipin and flotillin proteins. 相似文献
110.