Determination of Ochratoxin A in Bread: Evaluation of Microwave-Assisted Extraction Using an Orthogonal Composite Design Coupled with Response Surface Methodology

An analytical method using microwave-assisted extraction (MAE) and liquid chromatography (LC) with fluorescence detection (FD) for the determination of ochratoxin A (OTA) in bread samples is described. A 2⁴ orthogonal composite design coupled with response surface methodology was used to study the influence of MAE parameters (extraction time, temperature, solvent volume, and stirring speed) in order to maximize OTA recovery. The optimized MAE conditions were the following: 25 mL of acetonitrile, 10 min of extraction, at 80 °C, and maximum stirring speed. Validation of the overall methodology was performed by spiking assays at five levels (0.1–3.00 ng/g). The quantification limit was 0.005 ng/g. The established method was then applied to 64 bread samples (wheat, maize, and wheat/maize bread) collected in Oporto region (Northern Portugal). OTA was detected in 84 % of the samples with a maximum value of 2.87 ng/g below the European maximum limit established for OTA in cereal products of 3 ng/g.     

Using grounded theory as a method for rigorously reviewing literature

This paper offers guidance to conducting a rigorous literature review. We present this in the form of a five-stage process in which we use Grounded Theory as a method. We first probe the guidelines explicated by Webster and Watson, and then we show the added value of Grounded Theory for rigorously analyzing a carefully chosen set of studies; it assures solidly legitimized, in-depth analyses of empirical facts and related insights. This includes, the emergence of new themes, issues and opportunities; interrelationships and dependencies in or beyond a particular area; as well as inconsistencies. If carried out meticulously, reviewing a well-carved out piece of literature by following this guide is likely to lead to more integrated and fruitful theory emergence, something that would enrich many fields in the social sciences.     

Funding of applied behavior analysis services: Current status and growing opportunities.

Across the United States, unprecedented numbers of individuals with disabilities are transitioning from mental institutions and developmental centers to community-based settings. As the growing tide of individuals needing community-based services advances, the daunting task of procuring the resources necessary to support them is at hand. Practitioners of applied behavior analysis (ABA), in conjunction with professionals from disciplines such as psychiatry, psychology, medicine, and other specialized ancillary services including occupational therapy, physical therapy and speech and language pathology, have been able to forge beneficial partnerships to maintain the movement to community-based life for individuals with long-term support needs. In this article, we provide an overview of funding options for ABA services at the federal, state, and local levels and for various disability types. We also discuss current and future initiatives to increase funding for ABA services for specific populations who are currently underserved. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The first measurements of soft x-ray flux from ignition scale Hohlraums at the National Ignition Facility using DANTE (invited)

The first 96 and 192 beam vacuum Hohlraum target experiments have been fielded at the National Ignition Facility demonstrating radiation temperatures up to 340 eV and fluxes of 20 TW/sr as viewed by DANTE representing an ～20?times flux increase over NOVA/Omega scale Hohlraums. The vacuum Hohlraums were irradiated with 2 ns square laser pulses with energies between 150 and 635 kJ. They produced nearly Planckian spectra with about 30±10% more flux than predicted by the preshot radiation hydrodynamic simulations. To validate these results, careful verification of all component calibrations, cable deconvolution, and software analysis routines has been conducted. In addition, a half Hohlraum experiment was conducted using a single 2 ns long axial quad with an irradiance of ～2×10(15)?W/cm(2) for comparison with NIF Early Light experiments completed in 2004. We have also completed a conversion efficiency test using a 128-beam nearly uniformly illuminated gold sphere with intensities kept low (at 1×10(14)?W/cm(2) over 5 ns) to avoid sensitivity to modeling uncertainties for nonlocal heat conduction and nonlinear absorption mechanisms, to compare with similar intensity, 3 ns OMEGA sphere results. The 2004 and 2009 NIF half-Hohlraums agreed to 10% in flux, but more importantly, the 2006 OMEGA Au Sphere, the 2009 NIF Au sphere, and the calculated Au conversion efficiency agree to ±5% in flux, which is estimated to be the absolute calibration accuracy of the DANTEs. Hence we conclude that the 30±10% higher than expected radiation fluxes from the 96 and 192 beam vacuum Hohlraums are attributable to differences in physics of the larger Hohlraums.     

Ultralow-volume fraction collection from NanoLC columns for mass spectrometric analysis of protein phosphorylation and glycosylation

An ultralow volume fraction collection system referred to as nano fraction analysis chip technology (nanoFACT) is reported. The system collects 25-2500-nL fractions from 75-microm nanoLC columns into pipet tips at a user-defined, timed interval, typically one fraction every 15-120 s. Following collection, the fractions in the tip dry down naturally on their own in such a way as to create a concentrated band at the very end of the interior of the pipet tip. The fractions are then reconstituted directly in the pipet tips in approximately 250 nL of solvent prior to analysis. Because the chromatography and reconstitution solvent are independent, the reconstitution solvent can be selected to maximize ionization efficiency without compromising chromatography. In the infusion analysis of the nanoLC fractions, a low-flow electrospray chip is used which consists of 400 nozzles, each with an inner diameter of 2.5 microm and yielding flow rates of approximately 20 nL/min. Therefore, when reconstituted in 250 nL, each nanoLC fraction can be analyzed for over 10 min. This increase in analysis time allows for signal averaging, resulting in higher data quality, collision energy optimization, slower scanning techniques to be used, such as neutral loss and precursor ion scanning, higher resolution scans on FTMS instruments, and improved peptide quantitation. Furthermore, the nanoLC fractions could be archived in the pipet tips for analysis at a later date. Here, the advantages of nanoFACT are shown for phosphorylation analysis using bovine fetuin and glycosylation analysis using bovine ribonuclease B (RNase B). In the phosphorylation analysis, a comparison between conventional nanoLC and a nanoFACT analysis was performed. An MS/MS spectrum of a triply phosphorylated peptide, 313-HTFSGVApSVEpSpSSGEAFHVGK-333 could only be obtained using nanoFACT, not with nanoLC. Furthermore, spectral quality for the nanoFACT analysis was significantly improved over nanoLC. This was determined by comparing the number of diagnostic ions between the nanoFACT and nanoLC spectra, and it was found that the nanoFACT spectra contained a 19% or greater number of diagnostic ions for nonphosphorylated peptides and 55% or greater for phosphorylated peptides. For the glycosylation analysis, the glycosylation site of RNase B was fully characterized using 100 fmol of tryptic digest on a three-dimensional ion trap mass spectrometer.     

Detection of organophosphorus compounds by covalently immobilized organophosphorus hydrolase

As a consequence of organophosphorus (OP) toxins posing a threat to human life globally, organophosphorus hydrolase (OPH) has become the enzyme of choice to detoxify such compounds. Organophosphorus hydrolase was covalently immobilized onto a quartz substrate for utilization in paraoxon detection. The substrate was cleaned and modified prior to chemical attachment. Each modification step was monitored by imaging ellipsometry as the thickness increased with each modification step. The chemically attached OPH was labeled with a fluorescent dye (7-isothiocyanato-4-methylcoumarin) for the detection of paraoxon in aqueous solution, ranging from 10(-9) to 10(-5) M. UV-visible spectra were also acquired for the determination of the hydrolysis product of para-oxon, namely p-nitrophenol.     

High frequency heating of medium density fiberboard (MDF): theory and experiment

Medium-density fiberboard (MDF) is a wood-based panel manufactured from wood fibers with a synthetic adhesive through the conduction of heat from the hot platens. One alternative is the use of high-frequency (HF) heating, which has the advantage of reducing the press cycle, the platens temperature and the post-curing time, with constancy of resin formulation. For this approach, an electromagnetic (EM) heating model was developed and coupled with a three-dimensional model for heat and mass transfer and resin polymerization already existent. A solution of the Maxwell equations is used to determine the spatial distribution of the electric field inside the material and the absorbed power. MDF mat was assumed as a porous and homogeneous material at macroscopic level and a dielectric mixture at microscopic level (volume of control). The mat dielectric properties (wood fibers/particles and UF resin) were estimated using a “rule of mixture” and depend on local temperature and moisture content during the heating process. This dynamic model was used to predict the evolution of the local variables related to heat and mass transfer (temperature and moisture content), as well as the variable connected to the EM behavior (dielectric properties of the mat). The model performance was analyzed using the experimental results of HF () MDF heating. It was concluded that the model could suitably predict the evolution of the internal mat temperature during heating.     

Performance characteristics of an FT MS-based workflow for label-free differential MS analysis of human plasma: standards, reproducibility, targeted feature investigation, and application to a model of controlled myocardial infarction

Proteomics is undergoing a rapid transformation from a qualitative global peptide sequencing discipline into a quantitative, reproducibility-driven practice. Nowhere is this more evident than in the rapidly expanding field of protein biomarker discovery where the general goal is to uncover statistically robust patterns of differential expression between or among subjects/samples representing distinct biological/temporal states. This report presents the analytical characterization of a label-free LC FT-ICR-MS workflow for differential proteomics analysis of human plasma. The key elements discussed include (i) methodologies for performing properly replicated experiments with highly reproducible sample preparation and analysis, including the use of internal standards to quantify variance at different steps in the process, (ii) a new methodology for performing sample re-analysis that uses off-line targeted robotic acquisition of complementary spectral data (e.g. ECD and/or IRMPD) to enhance the identification of differentially expressed peptides/proteins, and (iii) data processing pipelines capable of integrating the automatic statistical analysis of the label-free (LC-) MS signal, together with the intuitive and highly interactive curation and annotation of differential features using the output from standard sequence database search programs. We illustrate the application of the complete sample-to-annotated-differential-peptides (-proteins) workflow by describing the acquisition and analysis of a large multidimensional dataset from patients undergoing a controlled myocardial infarction resulting in an experimental setup in which each patients serve as their own control. Furthermore, we discuss a couple illustrative examples of mid-level proteins observed in this study whose plasma concentrations change consistently within and across patients, in a treatment- and time-dependent fashion.     

Relations between personality and coping: A meta-analysis.

Personality may directly facilitate or constrain coping, but relations of personality to coping have been inconsistent across studies, suggesting a need for greater attention to methods and samples. This meta-analysis tested moderators of relations between Big Five personality traits and coping using 2,653 effect sizes drawn from 165 samples and 33,094 participants. Personality was weakly related to broad coping (e.g., Engagement or Disengagement), but all 5 traits predicted specific strategies. Extraversion and Conscientiousness predicted more problem-solving and cognitive restructuring, Neuroticism less. Neuroticism predicted problematic strategies like wishful thinking, withdrawal, and emotion-focused coping but, like Extraversion, also predicted support seeking. Personality more strongly predicted coping in young samples, stressed samples, and samples reporting dispositional rather than situation-specific coping. Daily versus retrospective coping reports and self-selected versus researcher-selected stressors also moderated relations between personality and coping. Cross-cultural differences were present, and ethnically diverse samples showed more protective effects of personality. Richer understanding of the role of personality in the coping process requires assessment of personality facets and specific coping strategies, use of laboratory and daily report studies, and multivariate analyses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)