Colletotrichum is the causal agent of anthracnose and other diseases on leaves, stems and fruits of numerous plant species, including several important crops. Accurate species identification is ...critical to understand the epidemiology and to develop effective control of these diseases. Morphologically-based identification of Colletotrichum species has always been problematic, because there are few reliable characters and many of these characters are plastic, dependent upon methods and experimental conditions. Rapid progress in molecular phylogenetic methods is now making it possible to recognise stable and well-resolved clades within Colletotrichum. How these should be reflected in a classification system remains to be resolved. An important step in providing a stable taxonomy for the genus is to epitypify existing names, and in so doing link them to genetically defined clades. We recommend a polyphasic approach to the recognition and identification of species within Colletotrichum, matching genetic distinctness with informative morphological and biological characters. This paper reviews various approaches in the study of Colletotrichum complexes including morphology, pathogenicity, physiology, phylogenetics and secondary metabolite production. A backbone phylogenetic tree using ITS sequence data from 42 ex-type specimens has been generated. Phylogenetic analysis using ITS sequence data is a useful tool to give a preliminarily identification for Colletotrichum species or place them in species complexes. However, caution must be taken here as the majority of the ITS sequences deposited in GenBank are wrongly named. Multi-gene phylogenetic data provides much better understanding of the relationships within Colletotrichum and should be employed where possible. We propose that an ideal approach for Colletotrichum systematics should be based on a multi-gene phylogeny, with comparison made with type specimens, and a well-defined phylogenetic lineage should be in conjunction with recognisable polyphasic characters, such as morphology, physiology, pathogenicity, cultural characteristics and secondary metabolites. Finally a set of protocols and methodologies is provided as a guideline for future studies, epitypification and the description of new species.
Filamentous fungi in the genus Colletotrichum are destructive pathogens that cause disease and crop losses in plants worldwide. Taxonomy and nomenclature in the group is confusing, even to scientists ...working in the field, and inaccurate diagnosis of species is not uncommon. In this review, we provide a overview of the 66 Colletotrichum names that are in common use, and the 19 recently used names which are regarded as doubtful. This paper represents the first comprehensive overview of the genus in 17 years, and is the first summary treatment of Colletotrichum to incorporate data generated through DNA analysis and phylogenetic systematics. Species are listed alphabetically and annotated with their taxonomic entry, teleomorph, hosts and disease, brief summaries of taxonomic and phylogenetic research, and outstanding issues for the genus that are neccesary to stabilize species names. Sequence data and type culture collection resources are also summarized. The paper serves to provide a new starting point for usage of current names in Colletotrichum and indicates future work needed.
The interface gold (Au) embrittlement failure mode resulting when a Au protective finish is not completely removed by the soldering process. has been investigated This failure mode places ...high-reliability electronics, which use the eutectic 63Sn-37Pb (wt%, abbreviated Sn-Pb) solder and Au protective finishes, at risk for latent service failures. Part 1 documented the Au/Sn-Pb) interface microstructures and especially, Kirkendall void formation, as a function of solid-state aging. Part 2 determines the compositions of the Au-Sn IMC layers and particles using electron probe microanalysis (EPMA). Two interface IMC layers were identified: a high-Au, secondary Au-Sn IMC layer adjacent to the Au layer, and a low-Au, primary Au-Sn IMC layer next to the Sn-Pb solder. The secondary IMC layer had compositions between the
δ
(AuSn) and
ε
(AuSn
2
) phases. The primary IMC layer exhibited compositions between the
ε
(AuSn
2
) and
η
(AuSn
4
) phases. The compositions varied as a function of the solid-state aging parameters as well as solder layer thickness. The controlling mechanism was Kirkendall voids and their effect on Au diffusion along the Au/secondary Au-Sn IMC interface. Gold-Sn IMC particles in the solder exhibited compositions like those of the primary Au-Sn IMC layer, but were a function of Au scavenging from the Sn-Pb microstructure. Nickel diffusion, which occurred into the remaining Au and IMC layers, had a driving force that was sensitive to either solder layer thickness or the remaining Au layer thickness, the latter being correlated to the former. Gold diffusion was also measured, which took place in the Ni layer.
New Zealand mudsnails (Potamopyrgus antipodarum (Gray, 1853)) are non-native snails that are increasingly spreading in freshwater systems in North America. Most invasive populations are parthenogenic ...and threaten native freshwater diversity. We observed variability of P. antipodarum fecundity each month for 16 months at a recently invaded site in Boulder Creek, Colorado. We collected 100 snails each month and dissected them to count embryos in the brood sac. We used a general linear model analysis to examine water-quality variables as predictors of the monthly variability in P. antipodarum fecundity. After dissecting 1600 snails, we observed four male individuals (<1%), brood sizes ranging from 0 to 70 embryos per snail, reproductively mature females at 3.2 mm in length or greater, and a significant relationship between snail length and embryo counts (r.sup.2 = 0.38, p < 0.001). The model with the highest level of support for predicting variability in snail fecundity included water temperature, snail shell length, water hardness (calcium carbonate), and nutrient levels (total phosphate) (adjusted r.sup.2 = 0.53, p < 0.01). These variables may be important for snail growth and promote increased rates of reproduction in this parthenogenic, invasive snail. These results can further inform efforts to model geographic areas at high risk of P. antipodarum establishment and rapid demographic growth.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Fat soluble vitamers (FSV) are several biochemically diverse micronutrients essential for healthy development, growth, metabolism, and cell regulation. We cannot synthesize FSV completely or at the ...required concentrations. Deficiency or excess of FSV can result in many health problems. Plasma is the most accessible sample matrix for the quantification of FSV. However, due to its complexity and other analytical challenges (e.g., FSV sensitivity to light, oxygen, heat, pH, chemical heterogeneity, standard availability), developing a method for the simultaneous quantification of multiple FSV at physiological concentrations has been challenging. In this systematic review, we examine the parameters and criteria used in existing Liquid Chromatography with tandem Mass Spectrometry (LC-MS/MS) methods for FSV quantification to the extraction method, chromatographic resolution, matrix effects, and method validation as critical to a sensitive and robust method. We conclude that the final FSV method sensitivity is predominantly based on aforementioned criteria and future method development using LC-MS/MS will benefit from the application of this systematic review.
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•FSV analytical methods continue to advance but have yet to be standardised.•Methodological validation and reporting are essential for rigour and reproducibility.•Standardised validation schema exist but are rarely adhered to.
Accurate photometric redshifts are calculated for nearly 200,000 galaxies to a 4.5 km flux limit of 613 kJy in the 8.5 deg super(2) Spitzer IRAC Shallow Survey. Using a hybrid photometric redshift ...algorithm incorporating both neural net and template-fitting techniques, calibrated with over 15,000 spectroscopic redshifts, a redshift accuracy of s= 0.06(1 + z) is achieved for 95% of galaxies at 0 < z < 1.5. The accuracy is s= 0.12(1 + z) for 95% of active galactic nuclei (AGNs) at 0 < z < 3. Redshift probability functions, central to several ongoing studies of the galaxy population, are computed for the full sample. We demonstrate that these functions accurately represent the true redshift probability density, allowing the calculation of valid confidence intervals for all objects. These probability functions have already been used to successfully identify a population of Spitzer-selected high-redshift (z > 1) galaxy clusters. We present one such spectroscopically confirmed cluster at (z) = 1.24, ISCS J1434.5+3427. Finally, we present a measurement of the 4.5 km-selected galaxy redshift distribution.
Summary
Background
Thiopurine hypermethylation towards 6‐methylmercaptopurine (6MMP) instead of 6‐thioguanine nucleotides (6TGN) is associated with inefficacy in patients with IBD. Allopurinol ...reverses such hypermethylation.
Aims
To prospectively determine efficacy of allopurinol‐thiopurine combination and to compare 2 doses of allopurinol.
Design
In a multicentre, double‐blind trial, patients with clinically active or steroid‐dependent IBD and thiopurine shunting were randomised to 50 or 100 mg/d allopurinol and 25% of their screening thiopurine dose, which was subsequently optimised, aiming for 6TGN of 260‐500 pmol/8x108RBCs. The primary endpoint was steroid‐free clinical remission at 24 weeks.
Results
Of 73 patients, 39 (53% 95% CI 42‐65) achieved steroid‐free remission, (54% with 50 mg/d and 53% with 100 mg/d). 81% were able to discontinue steroids. Therapeutic 6TGN levels were achieved in both groups. Final thiopurine doses were lower with 100 mg/d allopurinol (P < 0.005). 6MMP: 6TGN ratio decreased from mean 64 to 4 (P < 0.001), being higher with 50 mg/d (6 ± 1.83) than for 100 mg/d (1 ± 0.16, P = 0.003). Three patients on 50 mg/d failed to sustain low ratios at 24 weeks. Toxicity was minimal; three patients on 50 mg/d allopurinol developed transient leukopenia. Alanine aminotransferase concentrations decreased (P < 0.001) similarly in both arms. Faecal calprotectin levels at study end were lower in patients who achieved the primary endpoint (median 171 85‐541 vs 821110‐5892 ug/g, P = 0.03).
Conclusions
Low‐dose allopurinol‐thiopurine combination safely reverses shunting and optimises 6TGN with associated improvement in disease activity. 100 mg/d allopurinol is preferable due to greater metabolite profile stability and lower thiopurine dose without additional toxicity.
Linked ContentThis article is linked to Ansari and Aziz, and Friedman and Sparrow papers. To view these articles visit https://doi.org/10.1111/apt.14687 and https://doi.org/10.1111/apt.14798.
Geophysical and climate conditions play an important role in the distribution of organisms at both fine and broad scales. Headwater streams integrate changes at broad geographical scales and serve as ...important regions of nutrient processing and support high biodiversity. Stream salamanders are important members of headwater aquatic communities as both predators and prey. Combined with their biphasic life histories and physiological requirements, stream amphibians may serve as indicators for headwater stream conditions. We surveyed 50 streams for salamander occupancy, across eight counties of the southern Cumberland Plateau in Tennessee for which we are unaware of any stream amphibian distribution data. Our objective was to determine what variables best-predicted stream amphibian occupancy among species with variable life histories and habitat needs. Models were generated to determine the effects of elevation, catchment forest cover, and total catchment size as indicators of stream condition. We found species showed no significant responses to forest cover. Though forest cover has previously been the primary predictor of stream amphibian occupancy in streams across the United States, stream amphibian occupancy of the southern Cumberland Plateau was most closely associated with elevation and catchment size. Thus, the unique topography of the southern Cumberland Plateau may instead be the more important factor driving occupancy patterns. Despite limited evidence in this study for negative human impacts on salamander occupancy, low occupancy and abundance relative to other ecoregions suggests either poor quality habitat or large historic impacts. Developing a more comprehensive understanding of regional stream salamander occupancy patterns is necessary to ensure effective management and habitat conservation in a region with limited description of stream ecology.
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•Stream amphibians are good stream bioindicators.•Stream amphibian distributions are typically driven by forest loss.•Context can change biological responses to alternative human land-uses.•Complex topography can drive stream characteristics more than forest loss.•Regional topography drive stream amphibian distributions more than forest loss.
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