Weed management strategies for farming systems with herbicide tolerant cotton.

The introduction of glyphosate tolerant cotton has significantly improved the flexibility and management of a number of problem weeds in cotton systems. However, reliance on glyphosate poses risks to the industry in term of glyphosate resistance and species shift. The aims of this project were to identify these risks, and determine strategies to prevent and mitigate the potential for resistance evolution. Field surveys identified fleabane as the most common weed now in both irrigated and dryland system. Sowthistle has also increased in prevalence, and bladder ketmia and peachvine remained common. The continued reliance on glyphosate has favoured small seeded, and glyphosate tolerant species. Fleabane is both of these, with populations confirmed resistant in grains systems in Queensland and NSW. When species were assessed for their resistance risk, fleabane, liverseed grass, feathertop Rhodes grass, sowthistle and barnyard grass were determined to have high risk ratings. Management practices were also determined to rely heavily on glyphosate and therefore be high risk in summer fallows, and dryland glyphosate tolerant and conventional cotton. Situations were these high risk species are present in high risk cropping phases need particular attention. The confirmation of a glyphosate resistance barnyard grass population in a dryland glyphosate tolerant cotton system means resistance is now a reality for the cotton industry. However, experiments have shown that resistant populations can be managed with other herbicide options currently available. However, the options for fleabane management in cotton are still limited. Although some selective residual herbicides are showing promise, the majority of fleabane control tactics can only be used in other phases of the cotton rotation. An online glyphosate resistance tool has been developed. This tool allows growers to assess their individual glyphosate resistance risks, and how they can adjust their practices to reduce their risks. It also provides researchers with current information on weed species present and practices used across the industry. This tool will be extremely useful in tailoring future research and extension efforts. Simulations from the expanded glyphosate resistance model have shown that glyphosate resistance can be prevented and managed in glyphosate-tolerant cotton farming systems. However, for strategies to be successful, some effort is required. Simulations have shown the importance of controlling survivors of glyphosate applications, using effective glyphosate alternatives in fallows, and combining several effective glyphosate alternatives in crop, and these are the key to the prevention and management of glyphosate resistance.

Agronomic indices, growth, yield-contributing traits, and yield of dry-seeded rice under varying herbicides

Dry-seeded rice (DSR) is an emerging resource-conserving technology in many Asian countries, but weeds remain the major threat to the production of DSR systems. A field study was conducted in 2012 and 2013 at the International Rice Research Institute (IRRI), Los Baños, Philippines, to evaluate the performance of sole and sequential applications of preemergence (oxadiazon and pendimethalin), early postemergence (butachlor + propanil and thiobencarb + 2,4-D), and late postemergence herbicides (bispyribac-sodium and fenoxaprop + ethoxysulfuron) with different modes of action in comparison to manual weeding in DSR. The sequential applications of all preemergence and postemergence herbicides reduced weed density and biomass by 80–100% compared to the nontreated plots. The sole application of postemergence herbicides reduced weed density by only 44–54% and weed biomass by 51–61%, whereas oxadiazon alone reduced weed density and biomass by 96–100%. All herbicide treatments and manual weeding significantly affected tiller number, biomass, crop growth rate, agronomic indices, yield-contributing parameters (panicle density and filled grains), and yield (biological and grain) of rice. The highest grain yield was obtained in the manually weeded plots (5.9–6.1 t ha−1) and the plots treated with oxadiazon alone (5.4–5.6 t ha−1) and oxadiazon followed by postemergence herbicides (5.2–5.8 t ha−1). The lowest paddy yield (0.22 t ha−1) was achieved in the nontreated plots followed by the plots treated with the sole application of bispyribac-sodium and fenoxaprop + ethoxysulfuron. The results suggest that oxadiazon is the best broad-spectrum and economically effective herbicide when applied alone or in combination with other effective postemergence herbicides with different modes of action, depending on the weed species present in the field.

Phenology and seasonality in the tropical deciduous forest of Bandipur, South India

A long term study on the phenology of tree species of tropical dry deciduous forest ecosystem of Bandipur, South India has revealed patterns of strong seasonality with respect to leaf and fruit initiation as well as their abscission. The distribution of the duration of the various phenological events was observed to be skewed and there was little interannual variation in events such as flowering and fruiting. This suggests that there are, perhaps, no mast flowering or fruiting species present in the deciduous forests. The phenological changes appear to influence the food, feeding, movement patterns and sociality of the major mammals of this dry deciduous ecosystem.

Photocatalytic activity of tin-substituted TiO2 in visible light

Ultrafine powders of (Ti1-xSnx)O2, 0present in the lattice.

An assessment of the reduction potential of hydrogen plasma

Hydrogen plasma can be used for deoxidation of functional materials containing reactive metals in both bulk and thin film forms. Since the different species in the plasma are not in thermodynamic equilibrium, application of classical thermodynamics to the analysis of such a system is associated with some difficulties. While global equilibrium approaches have been tried, with and without additional approximations or constraints, there is some ambiguity in the results obtained. Presented in this article is the application of a local equilibrium concept to assess the thermodynamic limit of the reaction of each species present in the gas with oxides or oxygen dissolved in metals. Each reaction results in a different pal tial pressure of H2O. Because of the higher reactivity of the dissociated and ionized species and the larger thermodynamic driving force for reactions involving these species, they act as powerful reducing agents. It is necessary to remove the products of reaction from the plasma to prevent back reaction and gradual approach to global equilibrium. A quantitative description using the framework of the Ellingham-Richardson-Jeffes diagrams is presented.

An EXAFS study of the Mo/TiO2 hydrodesulphurization catalysis

In-situ EXAFS studies of sulphided Mo/TiO2 catalysts have shown that at low Mo loadings (2–4 wt%), an active species with a short Mo-S distance of 2.25 Å is formed, while on Mo/TiO2 with high Mo loadings as well as on Mo/gamma-Al2O3, bulk MoS2 (Mo-S, 2.42 Å) is formed. The species with the short Mo-S distance has Mo in an oxidation state close to 6 + and is likely to result from the sulphidation of the tetrahedral molybdate species present in the oxidic precursor at low Mo loadings. The calcination temperature of the oxidic precursor appears crucial, a high calcination temperature of 973 K favouring the formation of MoS3 on sulphidation, and a low calcination temperature of 623 K favouring MoS2.

Variations in the Levels of Aminoacylation and Modified Nucleotide Content Between Total Transfer-RNAS From Chloroplasts and Etioplasts in Cucumber Cotyledons

Total tRNAs isolated from chloroplasts and etioplasts of cucumber cotyledons were compared with respect to amino acid acceptance, isoacceptor distribution and extent of modification. Aminoacylation of the tRNAs with nine different amino acids studied indicated that the relative acceptor activities of chloroplast total tRNAs for four amino acids are significantly higher than etioplast total tRNAs. Two dimensional polyacrylamide gel electrophoresis (2D-PAGE) of chloroplast total tRNAs separated at least 32 spots, while approximately 41 spots were resolved from etioplast total tRNAs. Comparison of the reversed-phase chromatography (RPC-5) profiles of chloroplast and etioplast leucyl-, lysyl-, phenylalanyl-, and valyl-tRNA species showed no qualitative differences in the elution profiles. However, leucyl-, lysyl- and valyl-tRNA species showed quantitative differences in the relative amounts of the isoaccepting species present in chloroplasts and etioplasts. The analysis of modified nucleotides of total tRNAs from the two plastid types indicated that total tRNA from etioplasts was undermodified with respect to ribothymidine, isopentenyladenosine/hydroxy-isopentenyladenosine, 1-methylguanosine and 2-o-methylguanosine. This indicates that illumination may cause de novo synthesis of chloroplast tRNA-modifying enzymes encoded for by nuclear genes leading to the formation of highly modified tRNAs in chloroplasts. Based on these results, we speculate that the observed decrease in levels of aminoacylation, variations in the relative amounts of certain isoacceptors, and differences in the electrophoretic mobilities of some extra tRNA spots in the etioplast total tRNAs as compared to chloroplast total tRNAs could be due to some partially undermodified etioplast tRNAs. Taken together, the data suggested that the light-induced transformation of etioplasts into chloroplasts is accompanied by increases in the relative levels of some functional chloroplast tRNAs by post transcriptional nucleotide modifications.

Swift heavy ion induced structural, iono and photoluminescence properties of beta-CaSiO3:Dy3+ nanophosphor

CaSiO3:Dy3+ (1-5 mol%) nanophosphors have been prepared by a low temperature solution combustion method. The structural and luminescence (ionoluminescence; IL and photoluminescence; PL) studies have been carried out for pristine and ion irradiated samples. The XRD patterns of pristine sample show a prominent peak at (320) for the monoclinic structure of beta-CaSiO3. Upon ion irradiation, the intensity of the prominent peak is decreased at the fluence of 7.81 x 10(12) ions cm(-2) and at higher fluence of 15.62 x 10(12) ions cm(-2), the prominent peak completely vanishes. The decrease in peak intensity might be due to the stress induced point defects. On-line IL and in situ PL studies have been carried out on pelletized samples bombarded with 100 MeV Si7+ ions with fluences in the range (7.81-15.62) x 10(12) ions cm(-2). The characteristic emission peaks at 481,574, 664 and 754 nm recorded in both IL and PL are attributed to the luminescence centers activated by Dy3+ ions. It is found that IL and PL emissions intensity decreases with increase in Si7+ ion fluence. The decrease in intensity can be due to the destruction of Si-O-Si and O-Si-O type species present on the surface of the sample. FTIR studies also confirm the Si-O-Si and O-Si-O type species observed to be sensitive for swift heavy ion (SHI) irradiated samples. (C) 2012 Elsevier B.V. All rights reserved.

Effect of ambient on the resistance fluctuations of graphene

In this letter, we present the results of systematic experimental investigations of the effect of different chemical environments on the low frequency resistance fluctuations of single layer graphene field effect transistors. The shape of the power spectral density of noise was found to be determined by the energetics of the adsorption-desorption of molecules from the graphene surface making it the dominant source of noise in these devices. We also demonstrate a method of quantitatively determining the adsorption energies of chemicals on graphene surface based on noise measurements. We find that the magnitude of noise is extremely sensitive to the nature and amount of the chemical species present. We propose that a chemical sensor based on the measurement of low frequency resistance fluctuations of single layer graphene field effect transistor devices will have extremely high sensitivity, very high specificity, high fidelity, and fast response times. (c) 2015 AIP Publishing LLC.

Peces continentales de la Argentina: Iconografía. Gymnocharacinus bergii.

Espanol: Este trabajo tiene como objetivo la recopilación de dibujos y diferentes figuras de las especies presentes en nuestro territorio. Para ello, hemos utilizado como principales fuentes de información la obra de Ringuelet et al. (1967), Reis et al. (2003), López et al. (2003; 2006) y las bases de datos on-line de W. N. Eschmeyer y Fish Base. El tratamiento incluye una ficha individual con imágenes seleccionadas de la especie tratada y las que eventualmente hayan surgido por trabajos de índole anatómica. Se adjuntan las referencias de los trabajos utilizados en la confección de cada ficha. Esta es una publicación abierta, por lo que requerirá de actualización permanente, para lo cual sería necesario se sume a nuestra tarea la buena voluntad y colaboración de la comunidad ictiológica. Los compiladores entendemos que esta contribución, además de aportar valiosa información, rescata el trabajo de mujeres y hombres que son parte de la rica historia de la ictiología nacional y regional. (Texto en Espanol y PDF tiene viente dos paginas) English: The goal of this work is to present a collection of drawings and figures depicting the species present in our country. To achieve this, our main sources of information have been the works of Ringuelet et al. (1967), Reis et al. (2003), and López et al. (2003; 2006), as well as the online databases of W. N. Eschmeyer and Fish Base. Each species has an individual factsheet with selected images, including some from anatomical research works. All the works referenced are mentioned in each factsheet. This is an open-ended publication. As such, it will require permanent updating, which will depend on the good will and collaboration of the ichthyological community. As compilers, we understand that this contribution not only provides valuable information, but also highlights the work of men and women who are part of the rich history of our national and regional ichthyology. (Text is in Spanish. PDF contains 22 pages.)

Peces continentales de la Argentina: Iconografía. Lepidosiren paradoza.

Spanish: Este trabajo tiene como objetivo la recopilación de dibujos y diferentes figuras de las especies presentes en nuestro territorio. Para ello, hemos utilizado como principales fuentes de información la obra de Ringuelet et al. (1967), Reis et al. (2003), López et al. (2003; 2006) y las bases de datos on-line de W. N. Eschmeyer y Fish Base. El tratamiento incluye una ficha individual con imágenes seleccionadas de la especie tratada y las que eventualmente hayan surgido por trabajos de índole anatómica. Se adjuntan las referencias de los trabajos utilizados en la confección de cada ficha. Esta es una publicación abierta, por lo que requerirá de actualización permanente, para lo cual sería necesario se sume a nuestra tarea la buena voluntad y colaboración de la comunidad ictiológica. Los compiladores entendemos que esta contribución, además de aportar valiosa información, rescata el trabajo de mujeres y hombres que son parte de la rica historia de la ictiología nacional y regional. English: The goal of this work is to present a collection of drawings and figures depicting the species present in our country. To achieve this, our main sources of information have been the works of Ringuelet et al. (1967), Reis et al. (2003), and López et al. (2003; 2006), as well as the online databases of W. N. Eschmeyer and Fish Base. Each species has an individual factsheet with selected images, including some from anatomical research works. All the works referenced are mentioned in each factsheet. This is an open-ended publication. As such, it will require permanent updating, which will depend on the good will and collaboration of the ichthyological community. As compilers, we understand that this contribution not only provides valuable information, but also highlights the work of men and women who are part of the rich history of our national and regional ichthyology. (Texto en espanol y PDF tiene cuatorce paginas.)

Peces continentales de la Argentina: Bibliografía. Gymnocharacinus bergii.

Espanol: Este trabajo tiene como objetivo la recopilación de la información existente sobre las especies presentes en nuestro territorio. Para ello, se elaboraron fichas que contienen las referencias argentinas y de aquellas revisiones de autores extranjeros que involucran taxas de nuestro país. Como principales fuentes de información se consultaron Ringuelet et al. (1967), CLOFFSCA (2003), López et al. (2003; 2006), Liotta (2006) y las bases de datos on-line de W. N. Eschmeyer y Fish Base. Esta es una publicación abierta, por lo que requerirá de actualización permanente, para lo cual sería necesario se sume a nuestra tarea la buena voluntad y colaboración de la comunidad ictiológica. Esperamos con este aporte colaborar en la construcción de una base de datos de los peces continentales de la Argentina. La concreción de esta herramienta dará soporte a los planes generados desde los diferentes sectores involucrados en el tema, además de fomentar la difusión de la disciplina y la reafirmación de los derechos soberanos sobre nuestros recursos naturales. English: The goal of this work is to compile the existing information about the species present in our country. This has been done by means of datasheets that list both local references and reviews by foreign authors that include Argentine taxa. The main information sources consulted were Ringuelet et al. (1967), CLOFFSCA (2003), López et al. (2003; 2006), Liotta (2006) and the online databases of W. N. Eschmeyer and Fish Base. This is an open-ended publication. As such, it will require permanent updating, which will depend on the good will and collaboration of the ichthyological community. With this contribution, we hope to help to build a database of the freshwater fish of Argentina. The completion of this project will provide support to diverse plans emanating from different sectors, as well as promote the diffusion of this field of research and reaffirm Argentina’s sovereign rights over our natural resources. (Texto en Espanol Y English. PDF tiene nueve paginas.)

Peces continentales de la Argentina: Bibliografía. Lepidosiren paradoxa.

Espanol: Este trabajo tiene como objetivo la recopilación de la información existente sobre las especies presentes en nuestro territorio. Para ello, se elaboraron fichas que contienen las referencias argentinas y de aquellas revisiones de autores extranjeros que involucran taxas de nuestro país. Como principales fuentes de información se consultaron Ringuelet et al. (1967), CLOFFSCA (2003), López et al. (2003; 2006), Liotta (2006) y las bases de datos on-line de W. N. Eschmeyer y Fish Base. Esta es una publicación abierta, por lo que requerirá de actualización permanente, para lo cual sería necesario se sume a nuestra tarea la buena voluntad y colaboración de la comunidad ictiológica. Esperamos con este aporte colaborar en la construcción de una base de datos de los peces continentales de la Argentina. La concreción de esta herramienta dará soporte a los planes generados desde los diferentes sectores involucrados en el tema, además de fomentar la difusión de la disciplina y la reafirmación de los derechos soberanos sobre nuestros recursos naturales. English: The goal of this work is to compile the existing information about the species present in our country. This has been done by means of datasheets that list both local references and reviews by foreign authors that include Argentine taxa. The main information sources consulted were Ringuelet et al. (1967), CLOFFSCA (2003), López et al. (2003; 2006), Liotta (2006) and the online databases of W. N. Eschmeyer and Fish Base. This is an open-ended publication. As such, it will require permanent updating, which will depend on the good will and collaboration of the ichthyological community. With this contribution, we hope to help to build a database of the freshwater fish of Argentina. The completion of this project will provide support to diverse plans emanating from different sectors, as well as promote the diffusion of this field of research and reaffirm Argentina’s sovereign rights over our natural resources. (Texto en English y Espanol. PDF tiene ocho paginas.)

A bioregional classification of the continental shelf of northeastern North America for conservation analysis and planning based on representation

Understanding how well National Marine Sanctuaries and other marine protected areas represent the diversity of species present within and among the biogeographic regions where they occur is essential for assessing their conservation value and identifying gaps in the protection of biological diversity. One of the first steps in any such assessment should be the development of clearly defined and scientifically justified planning boundaries representing distinct oceanographic conditions and faunal assemblages. Here, we propose a set of boundaries for the continental shelf of northeastern North America defined by subdivisions of the Eastern Temperate Province, based on a review and synthesis (i.e. meta-analysis) of the scientific literature. According to this review, the Eastern Temperate Province is generally divided into the Acadian and Virginian Subprovinces. Broad agreement places the Scotian Shelf, Gulf of Maine, and Bay of Fundy within the Acadian Subprovince. The proper association of Georges Bank is less clear; some investigators consider it part of the Acadian and others part of the Virginian. Disparate perspectives emerge from the analysis of different groups of organisms. Further, while some studies suggest a distinction between the Southern New England shelf and the rest of the Mid-Atlantic Bight, others describe the region as a broad transition zone with no unique characteristics of its own. We suggest there exists sufficient evidence to consider the Scotian Shelf, Gulf of Maine, Georges Bank, Southern New England, and Southern Mid-Atlantic Bight as distinct biogeographic regions from a conservation planning perspective, and present a set of proposed mapped boundaries. (PDF contains 23 pages.)

Peces continentales de la Argentina: Iconografía. Brycon orbignyanus.

The goal of this work is to present a collection of drawings and figures depicting the species present in our country. To achieve this, our main sources of information have been the works of Ringuelet et al. (1967), Reis et al. (2003), and López et al. (2003; 2006), as well as the online databases of W. N. Eschmeyer and Fish Base. Each species has an individual factsheet with selected images, including some from anatomical research works. All the works referenced are mentioned in each factsheet. This is an open-ended publication. As such, it will require permanent updating, which will depend on the good will and collaboration of the ichthyological community. As compilers, we understand that this contribution not only provides valuable information, but also highlights the work of men and women who are part of the rich history of our national and regional ichthyology.