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morphological characterization of fungi associated with the ascochyta blight complex and pathogenic variability of mycosphaerella pinodes on field pea crops in central Alberta

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The Crop Journal 2015年第1期3卷 10-18页

作者： Hafiz Ahmed Kan-Fa Chang Sheau-Fang Hwang Heting Fu Qixing Zhou Stephen Strelkov Robert Conner bruce Gossen Crop Diversification Centre North Alberta Agriculture and Rural Development Department of Agricultural Food and Nutritional Science University of Alberta Agriculture and Agri-Food Canada (AAFC) Morden MB R6M 1Y5 Canada Agriculture and Agri-Food Canada (AAFC) Saskatoon SK S7N 0X2 Canada

Field pea crops in central Alberta were surveyed for ascochyta blight from 2011 to 2012 and fungal isolates were recovered from foliar lesions on selected plants. Cultural and microscopic characterization of the 275 isolates obtained revealed that 272 were of mycosphaerella pinodes and three were of Phoma medicaginis var. pinodella. Ascochyta pisi or Phoma koolunga were not identified. Isolates of m. pinodes were divided into two groups,GI and GII, based on visual assessment of culture characteristics. GI isolates(light to dark, mostly gray colony color; pycnidial distribution radial and concentric; conidia10.5–14.5 × 4.2–6.2 μm most with one septum, occasionally two, constricted at the septum;spore mass light buff to flesh color) were predominant(83%), while GII isolates(dark to gray colony color; pycnidia abundant; conidia 8–16 × 3.5–6.2 μm most with 1 septum, constricted at the septum; spore mass light buff to flesh color) were less common(17%). The cultures of GII isolates were similar to recent descriptions of A. pisi, but they differed in spore color. In a host differential study, 13 pathotypes of m. pinodes were identified from 110 single-spore isolates. Pathotype I was predominant(88 isolates) and virulent on all nine differential genotypes. The other pathotypes(pathotypes II–XIII) were rare(1–6 isolates of each).Comparison of the present results with earlier studies suggests that pathotype I has been prevalent for many years, and that its aggressiveness on the host differentials has increased over time. Emphasis should be placed on breeding for resistance to m. pinodes in field pea cultivars intended for deployment in central Alberta.

关键词： Ascochyta Phoma Resistance Virulence Pathotype

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Patterns of host use by a precocial obligate brood parasite, the Black-headed Duck: ecological and evolutionary considerations

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Chinese Birds 2013年第1期4卷 71-85,100页

作者： bruce E.LYON John m.EADIE 美国加州大学Santa Cruz分校生态与进化生物学系美国加州大学Davis分校野生动物与鱼类保护生物学系

The Black-headed Duck (Heteronetta atricapilla) is unique among obligate avian brood parasites because its highly precocial young leave the host nest shortly after hatching and impose no post-hatching costs on their hosts. Accordingly, we might expect host-parasite interactions in this parasite to differ strikingly from those of other brood parasites — they should be able to parasitize a broad diversity of hosts and be highly successful with these hosts. We conducted the second detailed study ever completed on patterns of host use in Black-headed Ducks. Based on four years of systematic searches of multiple marshes in Argentina, we found no evidence that Black-headed Ducks ever had nests of their own, confirming the previous conclusion that Black-headed Ducks are, indeed, true obligate brood parasites. Contrary to expectation, however, we found that Heteronetta is ecologically dependent on a surprisingly small number of host species — two species of coots and a gull — all of which are widespread and locally abundant species. Other species are numerically less important as hosts either because they are relatively uncommon, or because they are avoided by the ducks. In the three main host species, hatching success of the duck eggs was also surprisingly low (≤ 28%), based on expectations for a precocial parasite, mainly due to host rejection or neglect. mortality due to predation on host nests, in contrast, was low for all three primary host species. These observations corroborate Weller’s observations from a single-year study. The combination of a dependence on few primary hosts and a relatively low hatching success are inconsistent with some previous hypotheses for the evolution of obligate brood parasitism in Heteronetta. Instead, our observations, and those of Weller, suggest that intense nest predation in Austral wetlands, coupled with an abundance of a few common host species that aggressively defend their nests and obtain high nest success rates, may have been an

关键词： brood parasitism egg rejection Fulica Heteronetta atricapilla host use nest success precocial bird Red-gartered Coot Red-fronted Coot waterfowl

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Discussions on rockburst and dynamic ground support in deep mines

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Journal of Rock mechanics and Geotechnical Engineering 2019年第5期11卷 1110-1118页

作者： Charlie C.Li Peter mikula Brad Simser bruce Hebblewhite William Joughin Xiaowei Feng Nuwen Xu Norwegian University of Science and Technology (NTNU) Trondheim Norway mikula Geotechnics Pty. Ltd. Kalgoorlie Australia Glencore Company Sudbury Canada The University of New South Wales (UNSW) Sydney Australia SRK Consulting Johannesburg South Africa China University of mining and Technology Xuzhou China Sichuan University Chengdu China

The paper is a summary of discussions on four topics in rockburst and dynamic ground *** 1 is the mechanisms of *** events are classified into two categories in accordance with the triggering mechanisms,*** burst and fault-slip *** burst occurs on rock surfaces when the tangential stress exceeds the rock strength in hard and brittle ***-slip burst is triggered by fault-slip induced *** 2 is prediction and forecasting of rockburst *** for a rockburst event must tell the location,timing and magnitude of the *** could simply foresee the probability of some of the three *** is extremely challenging to predict rockbursts and large seismic events with current knowledge and technologies,but forecasting is possible,for example the possible locations of strain burst in an underground *** present,the approach using seismic monitoring and numerical modelling is a promising forecasting *** 3 is preconditioning *** current preconditioning methods are blasting,relief-hole drilling and *** fault-slip seismicity is difficult and challenging but has been *** very deep locations(>3000 m),the fracturing could extend from the excavation face to a deep location ahead of the face and therefore preconditioning is usually not *** 4 is dynamic ground support against *** ground support requires that the support system be strong enough to sustain the momentum of the ejecting rock on one hand and tough enough on the other hand to absorb the strain and seismic energies released from the rock *** current dynamic support systems in underground mining are composed of yielding tendons and flexible surface retaining elements like mesh/screen and *** props and engineered timber props are also used for dynamic support.

关键词： Rockburst Seismic event Dynamic ground support Forecasting Preconditioning

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Evaluation of Parametric Limitations in Simulating Greenhouse Gas Fluxes from Irish Arable Soils Using Three Process-Based models

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Agricultural Sciences 2016年第8期7卷 503-520页

作者： mohammad I. Khalil mohamed Abdalla Gary Lanigan bruce Osborne Christoph müller UCD School of Biology & Environmental Science and UCD Earth Institute University College Dublin Dublin Ireland Institute of Biological & Environmental Sciences University of Aberdeen Scotland UK Teagasc Environment Research Centre Johnstown Castle Wexford Ireland Department of Plant Ecology Justus-Liebig-University Giessen Giessen Germany

Globally a large number of process-based models have been assessed for quantification of agricultural greenhouse gas (GHG) emissions. modelling approaches minimize the presence of spatial variability of biogeochemical processes, leading to improved estimates of GHGs as well as identifying mitigation and policy options. The comparative performance of the three dynamic models (e.g., DNDC v9.4, DailyDayCent and ECOSSE v5+) with minimum numbers of common input parameters was evaluated against measured variables. Simulations were performed on conventionally-tilled spring barley crops receiving N fertilizer at 135 - 159 kg·N·ha-1·yr-1 and crop residues at 3 t·ha-1·yr-1. For surface soil nitrate (0 - 10 cm), the ECOSSE and DNDC simulated values showed significant correlations with measured values (R2 = 0.31 - 0.55, p 0.05). Only the ECOSSE-simulated N2O fluxes showed a significant relationship (R2 = 0.33, p 0.05) with values measured from fertilized fields, but not with unfertilized ones. The DNDC and DailyDayCent models significantly underestimated seasonal/annual N2O fluxes compared to ECOSSE, with emission factors (EFs), based on an 8-year average, were 0.09%, 0.31% and 0.52%, respectively. Predictions of ecosystem respiration by both DailyDayCent and DNDC showed reasonable agreement with Eddy Covariance data (R2 = 0.34 - 0.41, p 0.05). Compared to the measured value (3624 kg·C·ha-1·yr-1), the ECOSSE underestimated annual heterotrophic respiration by 7% but this was smaller than the DNDC (50%) and DailyDayCent (24%) estimates. All models simulated CH4 uptake we

关键词： Greenhouse Gases Arable Lands Input Parameters Process-Based models Ireland

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Alternate Wetting and Drying of Rice Reduced CH4 Emissions but Triggered N2O Peaks in a Clayey Soil of Central Italy

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Pedosphere 2016年第4期26卷 533-548页

作者： Alessandra LAGOmARSINO Alessandro Elio AGNELLI bruce LINQUIST maria Arlene ADVIENTO-BORBE Alberto AGNELLI Giacomo GAVINA Stefano RAVAGLIA Rossana monica FERRARA Consiglio per la Ricerca in agricoltura e l'analisi dell'Economia Agraria centro di ricerca per l'Agro Biologia e la Pedologia 50121 Firenze Department of Plant Sciences University of California Davis CA 95616 Dipartimento di Scienze Agrarie Alimentari e Ambientali Universita di Perugia 06123 Perugia Societa Italiana Sementi S. Lazzaro di Savena 40068 Bologna Consiglio per la Ricerca in agricoltura e l'analisi dell'Economia Agraria Research Unit for Cropping Systems in Dry Environments70125 Bari

Reducing CH4 and N20 emissions from rice cropping systems while sustaining production levels with less water requires a better understanding of the key processes involved. Alternate wetting and drying （AWD） irrigation is one promising practice that has been shown to reduce CH4 emissions. However, little is known about the impact of this practice on N20 emissions, in particular under mediterranean climate. To close this knowledge gap, we assessed how AWD influenced grain yield, fluxes and annual budgets of CH4 and N20 emissions, and global warming potential （GWP） in Italian rice systems over a 2-year period. Overall, a larger GWP was observed under AWD, as a result of high N20 emissions which offset reductions in CH4 emissions. In the first year, with 70% water reduction, the yields were reduced by 33%, CH4 emissions decreased by 97%, while N20 emissions increased by more than 5-fold under AWD as compared to PF; in the second year, with a 40% water saving, the reductions of rice yields and CH4 emissions （13% and 11%, respectively） were not significant, but N20 fluxes more than doubled. The transition from anaerobic to aerobic soil conditions resulted in the highest N20 fluxes under AWD. The duration of flooding, transition to aerobic conditions, water level above the soil surface, and the relative timing between fertilization and flooding were the main drivers affecting greenhouse gas mitigation potential under AWD and should be carefully planned through site-specific management options.

关键词： aerobic soil conditions fertilization global warming potential greenhouse gas mitigation potential water saving

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Polyaniline Nanofiber Composites with Amines:Novel materials for Phosgene Detection

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Nano Research 2009年第2期2卷 135-142页

作者： Shabnam Virji Robert Kojima Jesse D.Fowler Joey G.Villanueva Richard B.Kaner bruce H.Weiller materials Processing and Evaluation Department Space Materials LaboratoryThe Aerospace CorporationP.O.Box 92957/M2-248Los AngelesCA 90009USA Department of Chemistry&Biochemistry and California NanoSystems Institute University of CaliforniaLos AngelesLos AngelesCA 90095-1569USA

Several orders of magnitude of change in resistance are observed upon chemical doping and dedoping of the conducting polymer *** large conductivity range can be utilized to make sensitive chemical ***,in its nanofiber form,has even greater sensing capabilities due to the small fiber diameters,high surface area,and porous nanofiber network that enhances gas diffusion into the *** nanofibers have been synthesized using a rapid mixing method and dispersed in water allowing them to be easily modified with water soluble agents,making new composite *** nanofiber composite materials can be used to enhance detection of analytes that unmodified polyaniline would not otherwise be able to *** detection mechanism involves the reaction of an additive with the analyte to generate a strong acid that is easily detected by polyaniline,resulting in orders of magnitude changes in *** reaction of the additive alone with the analyte produces no electrical response,*** this paper,an array of amine-polyaniline nanofiber composite materials is investigated for the detection of phosgene *** influence of environmental conditions such as humidity and temperature are examined and a detection mechanism is presented.

关键词： Polyaniline nanofibers conducting polymer amines chemical sensor phosgene

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棉花黄萎病菌致病类型及其分子指纹分析

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中国农业科学 1998年第3期31卷 56-61页

作者：朱有勇王云月ＤｉｌｂａｇＳ．Ｍ．ＢｒｕｃｅＲ．Ｌ．云南农业大学澳大利亚悉尼大学生命科学学院分子遗传学实验室

对２０个大丽轮枝菌菌株的致病性进行了测定和ＲＡＰＤ指纹扩增，完成了供试菌株致病类群与其ＲＡＰＤ指纹组间的相关性分析。结果表明，根据２０个菌株对５个棉花品种的抗感反应及其平均病情指数分为４种不同的致病类群；用１０个随机... 详细信息

对２０个大丽轮枝菌菌株的致病性进行了测定和ＲＡＰＤ指纹扩增，完成了供试菌株致病类群与其ＲＡＰＤ指纹组间的相关性分析。结果表明，根据２０个菌株对５个棉花品种的抗感反应及其平均病情指数分为４种不同的致病类群；用１０个随机引物对２０个菌株进行ＲＡＰＤ－ＰＣＲ扩增，产生９２条ＤＮＡ带（其中５１条为多态带）；用计算机进行聚类分析，２０个供试菌株聚类为９个ＲＡＰＤ指纹组。相关性分析表明，致病类群与ＲＡＰＤ指纹组无明显相关性；但与部分单引物扩增的ＲＡＰＤ谱型有明显对应关系，如引物ＯＰＣ－１５随机扩增的ＲＡＰＤ谱型，除致病类群ＶＧ３的菌株外，其余致病类群均有对应的ＲＡＰＤ指纹谱带；其它引物（ＯＰＣ－０５，ＯＰＭ－１３，ＯＰＡ－０２，ＯＰＬ－０２）也有相似的结果。

关键词：大丽轮枝菌致病类型 RAPD

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Characterization of the Hydrogeological Conditions of Some Portions of the Neoproterozoic Voltaian Supergroup in Northern Ghana

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Journal of Water Resource and Protection 2011年第12期3卷 861-875页

作者： Sandow mark Yidana Aliou Abdul-Samed bruce Banoeng-Yakubo Prosper m. Nude 不详

Spatial variations in the essential aquifer parameters obtained through regular aquifer tests were evaluated for some aquifers of the Neoproterozoic sedimentary aquifers of the Voltaian Basin. Ordinary least squares regression models have also been developed to relate aquifer transmissivity and specific capacity, and well yield and transmissivity. These analyses suggest that in the northern parts of the Voltaian, aquifer transmissivity exists in a non-linear relationship with specific capacity and yield. This is in keeping with the findings of previous research in the southern part of the Voltaian, and deviates from the regular Dupuit-Thiem relationship between the two major aquifer parameters. Lithology specific models have been developed in this study. The exponent of the non-linear models appears to be related to the lithology, and tends to approach unity in the mudstone and siltstone aquifers, whilst manifesting obvious departures from nonlinearity amongst the sandstone aquifers. This study finds that the sandstone aquifers are the most prolific and offer themselves as the best lithologies for drilling successful wells in the area. Linear prediction maps suggest that the most prolific aquifers are located in the northern parts of the study area, where aquifer transmissivity, specific capacity, and well yield values are quite high due to enhanced secondary permeabilities. There has been no obvious relationship between the major aquifer parameters and static water levels, which are quite high in the middle and western sections of the study area. The hydrogeological properties of rocks within the Voltaian appear to be based on discrete structural entities which manifest high variability in the study area. Even within the same lithology, standard deviations are quite high in the data for all the aquifer parameters examined in this study.

关键词： Savelugu-Nanton Regression Specific Capacity Transmissivity Yield Kriging

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Scaling of Reference Reach for Desired Bankfull Discharge

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International Journal of Geosciences 2014年第5期5卷 475-477页

作者： bruce m. mcEnroe C. Bryan Young John E. Shelley Department of Civil Environmental and Architectural Engineering University of Kansas Lawrence USA

The reference reach method is commonly used for natural stream design. In the reference reach approach, a stable reach is selected to serve as the design template for a design reach. The planform and profile of this reference reach must be scaled to fit the design site. Currently, the leading method for scaling uses a simple ratio of cross-sectional areas. This paper presents a simple method that employs hydraulic scaling to size the design reach to accommodate the desired bankfull flow. The method introduced in this paper is easy to use, does not require additional survey data, and should lead to more robust channel design.

关键词： Channel Design Restoration Streams Stream Improvement

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FFECTS OF FLOW INTENSITY, OBSTACLE ALIGNmENT AND CROSS-SECTION GEOmETRY ON SCOUR AT BRIDGE ABUTmENTS"?CARDOSO, A.H., SANTOS, J.S. and ROCA, m.

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International Journal of Sediment Research 2002年第4期17卷 336-340页

作者： bruce W.mELVILLE Civil Engineering NewZealand The University of Auckland Professor Private Bag

The authors present new measurements of maximum (equilibrium) local scour depth at bridge abutments, the new data being analysed in terms of the multiplying factors given in melville (1992, 1997) and melville and Coleman (2000). The design method presented in these publications is referred to here as the University of Auckland (UoA) method. The authors?data apply to the following factors: Pf (flow intensity), Pq (abutment alignment) and Pg (approach channel geometry).

关键词： SANTOS and ROCA A.H CARDOSO FFECTS OF FLOW INTENSITY J.S OBSTACLE ALIGNmENT AND CROSS-SECTION GEOmETRY ON SCOUR AT BRIDGE ABUTmENTS

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