A statistical resampling method to calculate biomagnification factors exemplified with organochlorine data from herring (Clupea harengus) muscle and guillemot (Uria aalge) egg from the Baltic sea

A novel method for calculating biomagnification factors is presented and demonstrated using contaminant concentration data from the Swedish national monitoring program regarding organochlorine contaminants (OCs) in herring (Clupea harengus) muscle and guillemot (Uria aalge) egg, sampled from 1996 to 1999 from the Baltic Sea. With this randomly sampled ratios (RSR) method, biomagnification factors (BMF(RSR)) were generated and denoted with standard deviation (SD) as a measure of the variation. The BMFRsR were calculated by randomly selecting one guillemot egg out of a total of 29 and one herring out of a total of 74, and the ratio was determined between the concentration of a given OC in that egg and the concentration of the same OC in that herring. With the resampling technique, this was performed 50 000 times for any given OC, and from this new distribution of ratios, BMF(RSR) for each OC were calculated and given as geometric mean (GM) with GM standard deviation (GMSD) range, arithmetic mean (AM) with AMSD range, and minimum (BMF(MIN)) as well as maximum (BMF(MAX)) biomagnification factors. The 14 analyzed OCs were p,p'DDT and its metabolites p,p'DDE and p,p'DDD, polychlorinated biphenyls (PCB congeners: CB28, CB52, CB101, CB118, CB138, CB153, and CB180), hexachlorocyclohexane isomers (alpha-, beta-, and gammaHCH), and hexachlorobenzene (HCB). Multivariate data analysis (MVDA) methods, including principal components analysis (PCA), partial least squares regression (PLS), and PLS discriminant analyses (PLS-DA), were first used to extract information from the complex biological and chemical data generated from each individual animal. MVDA were used to model similarities/dissimilarities regarding species (PCA, PLS-DA), sample years (PLS), and sample location (PLS-DA) to give a deeper understanding of the data that the BMF modeling was based upon. Contaminants that biomagnify, that had BMF(RSR) significantly higher than one, were p,p'DDE, CB118, HCB, CB138, CB180, CB153, ,betaHCH, and CB28. The contaminants that did not biomagnifywere p,p'DDT, p,p'DDD, alphaHCH, CB101, and CB52. Eventual biomagnification for gammaHCH could not be determined. The BMF(RSR) for OCs present in herring muscle and guillemot egg showed a broad span with large variations for each contaminant. To be able to make reliable calculations of BMFs for different contaminants, we emphasize the importance of using data based upon large numbers of, as well as well-defined, individuals.     

Effect of different extracting solutions on the electrodialytic remediation of CCA-treated wood waste Part I. Behaviour of Cu and Cr

Removal of Cu and Cr from chromated copper arsenate (CCA)-treated wood waste under batch electrodialytic conditions was studied. The effect of different types of extracting solutions, such as deionised water or aqueous solutions of NaCl, formic acid, oxalic acid, and EDTA, on the magnitude and direction of the fluxes of Cu- and Cr-containing species in the electrodialytic cell was investigated. Oxalic acid was found to have the best performance if simultaneous removal of the two elements is required (removal efficiencies of 80.5% for Cu and 87.4% for Cr, respectively). A mixture of oxalic acid and formic acid also led to similar removal efficiencies. In these experiments, the target elements were accumulated in both the anode and cathode compartments of the electrodialytic cell due to the formation of negatively charged complexes with the organic acids used besides the free cationic forms. The latter were not present if EDTA was the extracting solution resulting in directing the Cu and Cr fluxes to the anode compartment. Contrary, these fluxes were exclusively to the cathode compartment if deionised water or an aqueous solution of NaCl were used. These extracting solutions proved suitable for solubilising (re-mobilisation) of Cu but were less efficient for Cr removal (less than 20% removal). Overall, the results obtained show the important role of the proper selection of the type and composition of the extracting solution for the success of subsequent electrodialytic removal of Cu and Cr from CCA-treated wood waste.     

"Awareness of subtle emotional feelings: A comparison of long-term meditators and nonmeditators": Correction to Nielsen and Kaszniak (2006).

Reports an error in "Awareness of Subtle Emotional Feelings: A Comparison of Long-Term Meditators and Nonmeditators" by Lisbeth Nielsen and Alfred W. Kaszniak (Emotion, 2006[Aug], Vol 6[3], 392-405). The copyright attribution is incorrect. The article is in the public domain. (The following abstract of the original article appeared in record 2006-10747-005.) The authors explored whether meditation training to enhance emotional awareness improves discrimination of subtle emotional feelings hypothesized to guide decision-making. Long-term meditators and nonmeditators were compared on measures of self-reported valence and arousal, skin conductance response (SCR), and facial electromyography (EMG) to masked and nonmasked emotional pictures, and on measures of heartbeat detection and self-reported emotional awareness. Groups responded similarly to nonmasked pictures. In the masked condition, only controls showed discrimination in valence self-reports. However, meditators reported greater emotional clarity than controls, and meditators with higher clarity had reduced arousal and improved valence discrimination in the masked condition. These findings provide qualified support for the somatic marker hypothesis and suggest that meditation may influence how emotionally ambiguous information is processed, regulated, and represented in conscious awareness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Joint strength measurements of individual fiber-fiber bonds: An atomic force microscopy based method

We are introducing a method to measure tensile strength of individual fiber-fiber bonds within a breaking force range of 0.01 mN-1 mN as well as the energy consumed during breaking. Until now, such a method was not available. Using a conventional atomic force microscope and a specifically designed sample holder, the desired force and the breaking behavior can be analyzed by two different approaches. First, dynamic loading can be applied, where force-versus-distance curves are employed to determine the proportions of elastic energy and energy dissipated in the bond. Second, static loading is utilized to study viscoelastic behavior and calculate viscoelastic energy contributions. To demonstrate the capability of the proposed method, we are presenting results for breaking strength of kraft pulp fiber-fiber bonds in tensile opening mode. The procedure is by no means restricted to cellulose fibers, it has the potential to quantify joint strength of micrometer-sized fibers in general.     

Effect of leaving milk trucks empty and idle for 6 h between raw milk loads

The US Pasteurized Milk Ordinance (PMO) allows milk tanker trucks to be used repeatedly for 24 h before mandatory clean-in-place cleaning, but no specifications are given for the length of time a tanker can be empty between loads. We defined a worst-case hauling scenario as a hauling vessel left empty and dirty (idle) for extended periods between loads, especially in warm weather. Initial studies were conducted using 5-gallon milk cans (pilot-scale) as a proof-of-concept and to demonstrate that extended idle time intervals could contribute to compromised raw milk quality. Based on pilot-scale results, a commercial hauling study was conducted through partnership with a Pacific Northwest dairy co-op to verify that extended idle times of 6 h between loads have minimal influence on the microbiological populations and enzyme activity in subsequent loads of milk. Milk cans were used to haul raw milk (load 1), emptied, incubated at 30°C for 3, 6, 10, and 20 h, and refilled with commercially pasteurized whole milk (load 2) to measure cross-contamination. For the commercial-scale study, a single tanker was filled with milk from a farm known to have poorer quality milk (farm A, load 1), emptied, and refilled immediately (0 h) or after a delay (6 h) with milk from a farm known to have superior quality milk (farm B, load 2). In both experiments, milk samples were obtained from each farm's bulk tank and from the milk can or tanker before unloading. Each sample was microbiologically assessed for standard plate count (SPC), lactic acid bacteria (LAB), and coliform counts. Selected isolates were assessed for lipolytic and proteolytic activity using spirit blue agar and skim milk agar, respectively. The pilot-scale experiment effectively demonstrated that extended periods of idle (>3 h) of soiled hauling vessels can significantly affect the microbiological quality of raw milk in subsequent loads; however, extended idle times of 6 h or less would not measurably compromise milk quality in subsequent loads in commercial tankers. Current tanker sanitation practices appear to be sufficient for maintaining raw milk SPC, LAB, and coliform levels, which are important measures of milk quality.     

The Effects of Amylose and Starch Phosphate on Starch Gel Retrogradation Studied by Low‐field 1H NMR Relaxometry

Low‐field Nuclear Magnetic Resonance (23 MHz) was used to study the effects of the degree of phosphorylation, the amylose content and the amylopectin chain length distribution on gel retrogradation for a set of 26 starches, six of which were of crystal polymorph type A, 18 of type B and two of type C. The phosphate content ranged from 0 to 58.8 nmol Glc6P/mg and the amylose content from 0 to 72.1%. The starch pastes (13%, w/w) were measured before and after storage for six days at 35 °C. It was found that Principal Component Analysis (PCA) of the raw Carr‐Purcell‐Meiboom‐Gill (CPMG) relaxation curves from the two measurements (day 1 and day 7) could be used as a simple, illustrative way of describing the retrogradation. Three different behaviours were identified: One group of samples (mostly potato starches) slowly changed from a soft to a more rigid gel from day 1 to 7. A second group (mostly cereal starches) formed a rigid gel already before the first measurement and changed little after that. A third group comprised a few samples containing little or no amylose aged similarly to the first group of samples, but at a much slower rate. For the potato starches, a weak negative correlation (r = ‐0.63) was found between the degree of phosphorylation and the difference between the LF NMR relaxation curves of day 1 and day 7.     

Modification of the Ferrous Oxidation-Xylenol Orange Method for Determination of Peroxide Value in Highly Pigmented Sea Cucumber Viscera Lipid

A ferrous oxidation-xylenol orange (FOX) method was modified to measure the levels of hydroperoxides in highly pigmented sea cucumber (Cucumaria frondosa) viscera lipid. With the FOX method, oil hydroperoxides oxidize Fe(II) to Fe(III) ions, which in turn bind to xylenol orange (XO) to form a complex that has a maximum absorbance at 560 nm. When applied to lipid extracts containing high levels of carotenoid pigments, the carotenoids interfere in the absorbance measurement because the XO-complex and carotenoids absorb at the same wavelength. To avoid this, an approach was developed where carotenoids were removed from the solution containing the XO-complex before absorbance measurements were made. This was accomplished by aqueous extraction of the reaction solution, leaving an organic layer containing the carotenoid pigment. The absorbance of the aqueous layer was subsequently measured at 560 nm allowing for determination of the lipid hydroperoxide content (mmol kg⁻¹) using a cumene hydroperoxide calibration curve. The method was validated using oxidized, unpigmented fish oils. The modified FOX method described herein was linear, accurate, and precise, and was validated over a hydroperoxide concentration range of 5–35 meq kg⁻¹ lipid. This modified FOX method for hydroperoxide determination of highly pigmented lipids is a valuable alternative to the methods presently available for determination of peroxide values.     

Trends to Attain a Lower Interfacial Tension in a Revisited Pure Alkyl Polyethyleneglycol Surfactant–Alkane–Water Ternary System. Basic Concepts and Straightforward Guidelines for Improving Performance in Enhanced Oil Recovery Formulations

Surfactant–oil–water systems exhibit a low interfacial tension minimum when the interactions between the adsorbed surfactant with water exactly coincide with its interactions with oil. This occurrence takes place at the so‐called optimum formulation, which was conceptually derived by Winsor in the 1950s and rendered by numerical correlations for enhanced oil recovery in the 1970s. The actual low value of the interfacial tension minimum has been found to increase or decrease with formulation variables and though some hints are available, no general relationship has been reported up to now, probably because too many variables are involved in complex interactions. It is shown in the present article that a linear relationship between low‐tension performance and formulation variables can be found for very simple ternary systems containing a pure ethoxylated alcohol, n‐alkane and water at variable temperature, i.e., when there are only four degrees of freedom. In such a case the iso‐performance contours studied in bi‐dimensional spaces are reported to be almost straight lines and as a consequence the path to lower the tension through formulation adjustments is easy to find as being perpendicular as possible to the contours. On the other hand, it is shown that displacing the limit of restrictions like the surfactant precipitation boundary is a priority issue, thus justifying many trends which have been proposed on empirical grounds in the past years. The reported simple guidelines for a simple surfactant–oil–water ternary is likely to considerably facilitate the formulator's work in a real system with a score of formulation variables.