Norovirus (NoV) is a major cause of acute non-bacterial gastroenteritis in all age groups worldwide. To detect NoV from foods, polyethylene glycol (PEG) precipitation or ultracentrifugation methods are generally used with reverse transcription (RT)-PCR. These methods need to use complicated procedures and varied buffers depending on the kinds of food matrices. In this study, we suggested a universal method to recover NoV in food and water samples as a prior step to real-time RT-PCR. As a NoV surrogate model, feline calicivirus (FCV) was used. FCV was artificially inoculated to samples, and then concentrated by the adsorption-elution method using negatively charged membrane filters. The detection limit was 4.3×10¹ PFU/250 mL for distilled water, 4.3×10² PFU/250 mL for environmental waters, and 4.3×10² PFU/15 g for lettuce and oyster. We were able to identify the possibility of one universal and time-saving method to detect NoV in food and water samples without modifications.

A simple and reliable method for rapid and selective extraction and determination of trace levels of Cd²⁺ was developed by dispersive liquid–liquid microextraction (DLLME) coupled to flame atomic absorption spectrometry (FAAS) detection. The main factors affecting the DLLME, such as concentration of DPTH, pH, extraction and disperser solvent type and their volume, were optimized for the best extract efficiency. Under the optimum conditions, i.e., pH 5.4, [DPTH] = 6 × 10⁻³%, a preconcentration factor of 55 was reached. The lower limit of detection (LOD) obtained under the optimal conditions was 0.4 μg L⁻¹. The precision for 14 replicate determinations at 30 and 100 μg L⁻¹ of Cd was 2.7% and 1.9% relative standard deviation (R.S.D.), respectively. The calibration graph using the preconcentration method was linear from 5 to 100 μg L⁻¹, with a correlation coefficient of 0.9898. The proposed method was successfully applied to the preconcentration and determination of cadmium in food, vegetation, and water samples and in a BCR-176 standard reference material.

There are a number of potential opportunities associated with agricultural, food, and water nanotechnology for the poor, but to achieve such opportunities a number of challenges need to be overcome. This paper first provides a rapid assessment of key technologies that could have a large impact on the poor via increased agricultural productivity, improved food and water safety, and nutrition. Second, it reviews some of the main challenges to their deployment and adoption by the poor. It concludes with a discussion of the potential role of the CGIAR in facilitating the poor's access to beneficial nanotechnologies.

GRP40; IFPRI1 | Gruère Guillaume P., 'Agricultural, food, and water nanotechnologies for the poor Opportunities, constraints, and role of the Consultative Group on International Agricultural Research', , IFPRI, 2011

For decades, increasing land productivity was a major driver of improving food security and reducing rural poverty. However, with increasing water scarcities, competing water demand across different sectors, and increasing cost of investments in water resources development require a paradigm shift. Improving the productivity of water use is emerging as a new way of addressing water scarcity while reducing vulnerability and improving income. Increasing both physical and economic water productivities (quantity per drop and value per drop) are central to this approach. The extent to which physical and economic water productivity should be improved is and area and context specific. However, the approach is especially important in areas that are populated with large agriculturally dependent small-holder rural people and areas that experience recurrent droughts and floods and lack access to proper infrastructure. A major part of the Ganga-Brahamaputra-Meghna (MBG) river basins have such characteristics. This report examines the current situation of poverty, food security and water productivity and their linkages and knowledge gaps in the MBG basins.

In this work, a new method based on dispersive liquid–liquid microextraction (DLLME) preconcentration using tetrachloromethane (CCl₄) as extraction solvent was proposed for the spectrophotometric determination of cadmium and copper in water and food samples. The influence factors relevant to DLLME, such as type and volume of extractant and disperser solvent, concentration of chelating reagents, pH, salt effect, were optimized. Under the optimal conditions, the limits of detection for cadmium and copper were 0.01ng/L and 0.5μg/L, with enhancement factors (EFs) of 3458 and 10, respectively. The tremendous contrast of EFs could come from the different maximum absorption wavelength caused by the different extraction acidity compared with some conventional works and the enhancement effect of acetone used as dilution solvent during the spectrophotometric determination. The proposed method was applied to the determination of water and food samples with satisfactory analytical results. The proposed method was simple, rapid, cost-efficient and sensitive, especially for the detection of cadmium.

A simple, rapid, sensitive and environmentally friendly separation and preconcentration procedure, based on the carrier element free coprecipitation (CEFC) of Cu(II) and Cd(II) ions by using an organic coprecipitant, 2-{[4-(4-fluorophenyl)-5-sulphanyl-4H-1,2,4-triazol-3-yl]methyl}-4-{[(4-fluorophenyl) methylene]amino}-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (MEFMAT) was developed. The analyte ions were determined by flame atomic absorption spectrometric (FAAS) determinations. The optimum conditions for the coprecipitation process were investigated on several commonly tested experimental parameters such as pH of the solution, amount of MEFMAT, sample volume, standing time, centrifugation rate and time. The influences of some anions, cations and transition metals on the recoveries of analyte ions were also investigated, and no considerable interference was observed. The preconcentration factor was found to be 50. The detection limits for Cu(II) and Cd(II) ions based on the three times the standard deviation of the blanks (N:10) were found to be 1.49 and 0.45μgL⁻¹, respectively. The relative standard deviations were found to be lower than 3.5% for both analyte ions. The method was validated by analyzing two certified reference materials (CRM-TMDW-500 Drinking Water and CRM-SA-C Sandy Soil C) and spike tests. The procedure was successfully applied to sea water and stream water as liquid samples and tobacco, hazelnut and black tea as solid samples.

There are a number of potential opportunities associated with agricultural, food, and water nanotechnology for the poor, but to achieve such opportunities a number of challenges need to be overcome. This paper first provides a rapid assessment of key technologies that could have a large impact on the poor via increased agricultural productivity, improved food and water safety, and nutrition. Second, it reviews some of the main challenges to their deployment and adoption by the poor. It concludes with a discussion of the potential role of the CGIAR in facilitating the poor's access to beneficial nanotechnologies.

O Semiárido brasileiro tem entre suas principais características a instabilidade climática e, esta situação poderá se tornar mais grave se confirmadas as previsões de redução das precipitações em até 20%. Isto trará consequências sérias para a agricultura familiar, principalmente para aquelas famílias que não dispõem de infraestrutura hídrica em suas propriedades, o que poderá afetar ainda mais os aspectos de quantidade e de qualidade dos alimentos desse contingente populacional. Como forma de amenizar esses problemas, várias experiências de pesquisa foram realizadas utilizando água de chuva armazenada em cisterna para aplicar em fruteiras, visando reduzir o impacto da irregularidade das chuvas e promover a melhoria dos alimentos consumidos. Os resultados obtidos em áreas de produtores confirmam que a cisterna pode manter um pequeno pomar que poderá incrementar vitaminas, sais minerais, ferro, entre outros nutrientes na dieta das famílias, principalmente, de crianças. Também, apontam para a consolidação do programa de governo voltado para segurança alimentar e nutrição, em que utiliza a cisterna como estrutura de armazenamento de água de chuva para produção

Ingeniero Ambiental | Pregrado