Determination of Psoralens in Child Food (Soups and Baby Food) from Brazil by High-performance Liquid Chromatography (HPLC)

Psoralens are considered natural toxins, present in edible plants, which act as protectors against fungi, insects, and herbivores. In this study, an analytical procedure suitable for sample preparation and an HPLC-UV method were developed for the quantification of psoralens in child food (soups and baby food). The samples were lyophilized and 5.00 g of solid was extracted with 25 mL of MeOH:HCl (1000:1), under magnetic stirring at 40 °C for 30 min. Separation was carried out on a C18 column with a mobile phase consisting of acetonitrile (20 to 100%) and water. Spectrophotometric detection with a wavelength of 246 nm was used. The method to determine psoralens in child food showed adequate linearity, repeatability, and accuracy. The limits of detection (LOD) and quantification (LOQ) obtained for psoralens were 0.02 and 0.08 μg g^?1, respectively. The concentrations (minimum–maximum in μg/100 g) of psoralens in the samples ranged from 71.9 to 877.4. The intake of approximately 45-mg psoralen and UVA exposure can result in various skin lesions. Therefore, the results showed that the developed method is simple, fast, and reliable for the determination of psoralens in child food (soups and baby food).     

Biomechanical versus inertial information: Stable individual differences in perception of self-rotation.

When turning without vision or audition, people tend to perceive their locomotion as a change in heading relative to objects in the remembered surroundings. Such perception of self-rotation depends on sensitivity to information for movement from biomechanical activity of the locomotor system or from inertial activation of the vestibular and postural systems. The authors report 3 experiments that investigated the relative contributions of biomechanical and inertial information to perceiving the speed of self-rotation. Using a circular treadmill, the proportions of the 2 sources of proprioceptive information were varied, creating walking conditions with a constant rate of biomechanical activity but with variable speeds of rotation relative to inertial space. The results reveal stable individual differences in sensitivity to information for the perception of locomotion. Just more than half of the participants based their perceived speed of self-rotation on biomechanical information, whereas the others based theirs on inertial information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial assimilation of minority groups

The recent debate on segregation in western European countries has been framed with significantly different assumptions from those prevailing in the study of minority-group housing segregation in the US. In the public debate in western European countries, segregation of minority groups is increasingly blamed on those groups themselves. In a now popular narrative, they are thought of as sticking consciously together and not subscribing to the aspirations, including housing preferences, of the indigenous population. Using data on suburbanization in the Rotterdam metropolitan area, we show that that economically successful and socially upwardly mobile migrants of Surinamese background show the same volume and pattern of geographic mobility as do the native Dutch. On top of that, they use the same narrative as other suburbanizing groups in the past. Contrary to the now dominant policy view, it seems that class, more so than ethnicity, determines metropolitan residential patterns and the dynamics behind them. Our data do not corroborate the notion that members of migrant groups have housing preferences that significantly deviate from those of the middle-class Dutch.     

Preparation of 1,3,5-tribenzylhexahydro-1,3,5-triazine-CrCl3 catalyst supported on SiO2 and activity studies in ethylene polymerization

In the present work, 1,3,5-tribenzylhexahydro-1,3,5-triazine-CrCl₃ (TAC-CrCl₃) complex was supported on Stöber silica and on commercial porous SiO₂. Ethylene polymerization and copolymerization were carried with methylaluminoxane (MAO) as co-catalyst. In the polymerization of ethylene, the silica-supported TAC-CrCl₃ catalysts exhibit activity values from 200 to 374 kg/molCr/h with Stöber silica being the best. In the co-polymerization of ethylene with 1-hexene, the yields of polymer are 34–117 kg/molCr/h; the highest value is again obtained with Stöber silica as a support. The polymers were characterized by X-ray diffraction, solid-state ¹³C NMR, viscosimetric analysis and differential scanning calorimeter (DSC). The polymers have molecular weights of 23,000–40,000 g/mol; crystallinity varies from 60 to 68% and melting points in the range 125–131 °C.     

Capturing latecomer advantages in the adoption of biofuels: The case of Argentina

Although Argentina came late to the biofuels revolution, a series of measures taken recently at federal and provincial government level have created new opportunities. New federal laws on biofuels promotion have sparked an investment boom. The main activity has been in the biodiesel sector—partly because diesel is the dominant fuel sector in Argentina, and partly because the country had already engineered a soy revolution over the past 15 years, becoming the world's largest exporter of soy oil and soy meal. Biodiesel allows this revolution to be extended—from soy as foodstuff to soy as fuelstock. The biodiesel revolution now underway promises to extend Argentina's latecomer advantages by combining greater scale and lower costs with introduced technical innovations such as genetically modified crops and no-till farming. In this way, Argentina can be seen to be demonstrating the superiority of biofuel production in countries of the South over the conditions obtaining in countries of the North—including superior resources availability, superior energetics and lower costs. Whereas Brazil has demonstrated its superiority in sugarcane-based ethanol, Argentina is about to demonstrate its superiority in soy-based biodiesel.     

The Empirical Likelihood method applied to covariance matrix estimation

This paper presents a new estimation scheme for signal processing problems in unknown noise field. The Empirical Likelihood has been introduced in the mathematical community, but, surprisingly, it is still unknown in the signal processing community. This estimation method is an alternative to estimate unknown parameters without using a model for the probability density function.The aim of this paper is twofold: first, the Empirical Likelihood theory is presented and revisited thanks to the moment method. Its properties are derived. Second, to emphasize all the potentiality of this method, we address the problem of Toeplitz matrix estimation: this leads us to obtain improved estimates in comparison to conventional ones, as shown in simulations.     

Validation of French-Canadian versions of the Empathy Quotient and Autism Spectrum Quotient.

The primary objective of this study was to validate French-Canadian versions of the Autism Spectrum Quotient (AQ-F) and the Empathy Quotient (EQ-F) in normal and pathological samples. These versions of the scales were administered to 100 undergraduate university students in the hard science or humanities fields and to 23 individuals diagnosed with autism spectrum disorder (ASD). For both scales, obtained data were partially consistent with English versions. The EQ-F and AQ-F scores were negatively correlated, and the ASD group differed significantly from both control groups, scoring lower on the EQ-F and higher on the AQ-F. These preliminary results support the validity of the AQ-F and EQ-F as screening tools in French-speaking populations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assurance of compliance within the production chain of food contact materials by good manufacturing practice and documentation – Part 2: Implementation by the compliance box; call for guidelines

EU legislation requires that compliance of food contact materials (FCMs) with Article 3 of the Framework regulation 1935/2004 be established by good manufacturing practice (GMP): compliance must be dealt with at all stages of the manufacturing supply chain, either concluding compliance regarding a given aspect or delegating specified work to later stages. If there is specific legislation in place, compliance declarations (CDs) are required at all stages of production.This paper proposes the compliance box (CB) to structure the compliance work and format the documentation: section (1) identifies the business operator, (2) specifies the product and its intended uses, (3) deals with the compliance of the substances used, (4) with specific migration limits (SMLs) and other substance-related restrictions, (5) with the overall migration limit (OML), (6) with the impurities, reaction products and other not intentionally added substances (NIAS), and (7) closes with the issue date and signature. At each production stage, the compliance work is documented in the format of a CB which remains in-house (supporting documentation, here called food contact documentation FCDoc). A CB with sections 3–6 being reduced to delegated compliance work and, if required, CDs accompanies the product (food contact declaration, FCDec). During the manufacturing process, CBs merge to the point where compliance work is concluded.For the implementation, guidelines are needed, e.g., on unclear conventions applied in the past, a threshold of control, the range of the manufacturing process encompassed, the types of justifications considered acceptable for stating compliance, and the estimation of exposure. The main difficulties are in the unintentionally added substances.     

Aquifer Management with Logistic Recharge

Abstract

Theoretical principles of sustainable aquifer management are laid out in this work. The premise of our treatment is that groundwater is a renewable, although exhaustible, natural resource. The theory of this work is aimed at aquifers with a relatively homogeneous recharge that can be approximated by a logistic growth function. Sustainable aquifer exploitation occurs when the rate of ground-water extraction is equal to or less than the natural rate of groundwater replenishment for any level of aquifer storage. There can be many levels of sustainable aquifer exploitation depending on the level of aquifer storage, but there may be only one that maximizes economic returns under a variety of economic and aquifer conditions. Different strategies for sustainable exploitation are derived depending on whether or not the analysis considers tradeoffs among: (i) current and future exploitation; (ii) constant and dynamic aquifer storage conditions; and (iii) regulated and unregulated aquifer exploitation. Key factors affecting sustainable exploitation strategies include: (1) the market price of groundwater; (2) the cost of groundwater extraction; (3) the aquifer storage and natural replenishment characteristics; (4) institutional and environmental regulations on groundwater extraction; and (5) the real discount rate. An example of sustainable groundwater exploitation in Santa Barbara, California, illustrates the methods of this article.