Comparison of asian soybean rust chemical control on a susceptible and a resistant cultivar in Brazil.

The development of resistant cultivars to the Asian soybean rust (ASR), caused by Phakopsora pachyrhizi, brought an additional tool to the disease management in Brazil. ASR develops slower in resistant cultivars than in susceptible ones, allowing a reduction of the number of fungicide sprays, but chemical control is still necessary. A field trial was conducted in Ponta Grossa, Parana State, in order to compare the effects of ASR chemical control with four fungicide formulations, in both resistant (BRSGO 7560) and susceptible (CD 249 RR) soybean cultivars. The fungicides were applied twice, beginning at soybean growth stage R3?R4, when first uredinia were observed, and at soybean stage R5.3?R5.4. The fungicides used were premix formulations of pyraclostrobin + epoxiconazole + fluxapyroxad (40+64.8+40 g a.i./ha), azoxystrobin + cyproconazole (60+24 g a.i./ha), pyraclostrobin + epoxiconazole (79.8+30 g a.i./ha), and epoxiconazole (125 g a.i./ha). The ASR severity at soybean growth stage R7 on nonsprayed plots reached 75.4% on the resistant cultivar and 98.6% on the susceptible cultivar. Lower ASR severity index were observed in the resistant cultivar, with the treatments pyraclostrobin + epoxiconazole (9.8%), pyraclostrobin + epoxiconazole + fluxapyroxad (10.5%), and azoxystrobin + cyproconazole (10.9%), with an average of disease control ranging from 90.8 to 91.3%. The treatments with pyraclostrobin + epoxiconazole and pyraclostrobin + epoxiconazole + fluxapyroxad provided the lower yield reductions on both soybean cultivars. The yield and grain weight reductions in the nonsprayed treatment were 32 and 28%, respectively, on the resistant cultivar and 44 and 32%, respectively, on the susceptible cultivar

Applications of IGY antibodies to influenza a virus detection in infected cells by immunocytochemistry.

Introduction and objectives: Influenza is a disease caused by infection of the host respiratory tract by influenza type A virus that affects a wide variety of species, including human, swine, equine, poultry and sea mammals. The viral RNA is encapsidated by the nucleoprotein (NP), which is a highly conserved protein among influenza A viruses. Detection of influenza virus can be accomplished by assessing specific immune response to the virus, by direct detection of viral RNA or virus antigen in infected tissues. Some diagnostic tests use antibodies produced in mammals to influenza virus detection. However, due to high cost and concerns related to animal welfare, alternative production of antibodies in mammals has been described. The immunoglobulin Y (IgY) is a class of antibodies in poultry that is transferred to the egg yolk. These antibodies are easy to obtain from eggs and their use has been described for immunotherapy, immunodiagnosis and research. The objective of this study was to produce IgY antibodies anti-NP in laying hens immunized with influenza A virus NP, and to evaluate the purified IgY antibodies in influenza virus detection

Determination of Cu in blood: Via direct analysis of dried blood spots using high-resolution continuum source graphite furnace atomic absorption spectrometry

The performance of state-of-the-art high-resolution continuum source graphite furnace atomic absorption spectrometry (HR CS GFAAS) instrumentation and four novel devices to produce dried blood spots of perfectly defined volumes is evaluated with the aim of developing a simple, direct method for the determination of Cu in blood samples. In all cases, it is feasible to obtain accurate quantitative information using any of the four devices tested (Mitra, HemaXis DB10, Capitainer qDBS and HemaPEN) via simple external calibration with aqueous standards. One of the main differences in the performance of such devices is related to the blanks obtained, such that HemaXis DB10 and HemaPEN are preferred when abnormally low Cu levels (500 µg L-1 or lower), associated with some diseases, need to be determined. The results prove that accurate values with RSD values below 10% can be achieved for these devices even for such Cu levels, while for Capitainer qDBS and, to a higher extent, for Mitra, blank variations will ultimately increase the uncertainty. It is important to stress that analysis of four real samples using both venipuncture and all the DBS specimens showed a very good agreement. Thus, the approach proposed could be readily applied, such that patients with disorders requiring Cu control can prepare their own samples and submit them via postal mail to labs for HR CS GFAAS direct and fast analysis. © The Royal Society of Chemistry

21 de setiembre: día de la ciencia y la técnica

Con motivo del 3O aniversario de la instauración del 21 de setiembre como día de la Ciencia y la Técnica en la Provincia de Buenos Aires, la CIC le ha solicitado a un grupo selecto de científicos, su opinión sobre aspectos esenciales del quehacer científico y tecnológico. El presente texto contiene los siguientes trabajos: - Consideraciones acerca de la investigacion técnico-científica sobre materiales, por Eduardo R. Abril. - Ciencia y tecnología de alimentos, por Pedro Cattáneo - Ciencia y tecnología en química orgánica por Venancio Deulofeu. - Ciencia y tecnología - recursos humanos por Ernesto E. Galloni. - Discurso de apertura de la reunion sobre ciencia y tecnologia realizada en Mar del Plata del 6 al 8 de julio de 1978 por Luis F. Leloir. - Incidencia de la investigación en el desarrollo de la metalurgia por Roberto F. Recoder. - Importancia de la investigación matemática en la sociedad contemporánea por Luis A. Santaló. - La investigación en fisicoquímica y su proyección en el desarrollo científico y tecnológico por Hans J. Schumacher

ESR, raman and conductivity studies on fractionated poly(2-methoxyaniline-5-sulfonic acid)

Synthesis methods used to produce poly(2-methoxyaniline-5-sulfonic acid) (PMAS), a water soluble, self-doped conducting polymer, have been shown to form two distinctly different polymer fractions with molecular weights of approximately 2 kDa and 8 -10 kDa. The low molecular weight (LMWT) PMAS fraction is redox inactive and non-conducting while the high molecular weight (HMWT) PMAS is electro-active with electrical conductivities of 0.94 0.05 S cm-1. Previous investigations have illustrated the different photochemical and electrochemical properties of these fractions, but have not correlated these properties with the structural and electronic interactions that drive them. Incomplete purification of the PMAS mixture, typically via bag dialysis, has been shown to result in a mixture of approximately 50:50 HMWT:LMWT PMAS with electrical conductivity significantly lower at approximately 0.10 to 0.26 S cm-1. The difference between the electrical conductivities of these fractions has been investigated by the controlled addition of the non-conducting LMWT PMAS fraction into the HMWT PMAS composite film with the subsequent electronic properties investigated by solid-state ESR and Raman spectroscopies. These studies illustrate strong electronic intereactions of the insulating LMWT PMAS with the emeraldine salt HMWT PMAS to substantially alter the population of the electronic charge carriers in the conducting polymer. ESR studies on these mixtures, when compared to HMWT PMAS, exhibited a lower level of electron spin in the presence of LMWT PMAS indicative of the the formation of low spin bipolarons without a change the oxidation state of the conducting HMWT fraction