A Study of the Composition of Zinc Complex Cyanide Solutions by the Conductometric Method

As the method or analysis used up to the present time has failed to give quantitative results in determining the composition of zinc cyanide baths, conductometric methods were adopted in this study. Supplementary tests were also carried out in this investigation

Family Permanence Versus the Best Interests of the Child

Historically, promoting family permanence (e.g., keeping the original parent-children relationships intact) has been controversial. At times, priority was given to the family of origin, but due to the best interests of the child principle, there has also been preference for foster placements and adoptions. This article presents the legal backdrop (e.g., the Adoption and Safe Families Act of 1997) and discusses history, as well as ethical and psychological issues. It is asserted that (1) at present, the concept of the best interests of the child is of foremost importance, and (2) biological and psychological parental qualities can be enhanced through preventive and remedial parent education in the family therapy context

The Role of Heme Chirality in the Circular Dichroism of Heme Proteins

The rotational strength (R) of the Soret transition in sperm-whale myoglobin (SW Mb), the hemoglobin from Chirononms thummi thummi (C17 Hb), and human hemoglobin (hHb) has been calculated using 20 high-resolution ( R-aro > R-pep. For CTT Hb and hHB, the orders were, respectively, R-int > R-pep > R-aro and R-int > R-aro approximate to R-pep. Human Hb alpha chains showed the same trend as CTT Hb. Only in the hHb beta chains did R-aro predominate, with the order R-aro > R-iot > R-pep. The total predicted R-tot for SW Mb, CTT Hb, and hHb averaged +0.77 +/- 0.10 (0.56-0.80), -0.37 +/- 0.12 (-0.5), and +0.31 +/- 0.17 DBM (0.23-0.50), respectively. (Values in parentheses are experimental values.) Thus, contrary to the currently accepted view, coupling with aromatic side-chain or peptide transitions is not the dominant factor in the Soret circular dichroism (CD) of these proteins. The Soret CD is dominated by intrinsic CD of the heme chromophore, of which vinyl torsion is the major determinant. This result suggests an explanation for the large effect of heme isomerism on the Soret CD of Mb and Hb. Rotation about the alpha-gamma axis may be associated with large changes in vinyl torsion and thus substantially alter the intrinsic CD, even reversing its sign

The Shivplot: a graphical display for trend elucidation and exploratory analysis of microarray data

BACKGROUND: High-throughput systems are powerful tools for the life science research community. The complexity and volume of data from these systems, however, demand special treatment. Graphical tools are needed to evaluate many aspects of the data throughout the analysis process because plots can provide quality assessments for thousands of values simultaneously. The utility of a plot, in turn, is contingent on both its interpretability and its efficiency. RESULTS: The shivplot, a graphical technique motivated by microarrays but applicable to any replicated high-throughput data set, is described. The plot capitalizes on the strengths of three well-established plotting graphics – a boxplot, a distribution density plot, and a variability vs intensity plot – by effectively combining them into a single representation. CONCLUSION: The utility of the new display is illustrated with microarray data sets. The proposed graph, retaining all the information of its precursors, conserves space and minimizes redundancy, but also highlights features of the data that would be difficult to appreciate from the individual display components. We recommend the use of the shivplot both for exploratory data analysis and for the communication of experimental data in publications

A methodology for global validation of microarray experiments

BACKGROUND: DNA microarrays are popular tools for measuring gene expression of biological samples. This ever increasing popularity is ensuring that a large number of microarray studies are conducted, many of which with data publicly available for mining by other investigators. Under most circumstances, validation of differential expression of genes is performed on a gene to gene basis. Thus, it is not possible to generalize validation results to the remaining majority of non-validated genes or to evaluate the overall quality of these studies. RESULTS: We present an approach for the global validation of DNA microarray experiments that will allow researchers to evaluate the general quality of their experiment and to extrapolate validation results of a subset of genes to the remaining non-validated genes. We illustrate why the popular strategy of selecting only the most differentially expressed genes for validation generally fails as a global validation strategy and propose random-stratified sampling as a better gene selection method. We also illustrate shortcomings of often-used validation indices such as overlap of significant effects and the correlation coefficient and recommend the concordance correlation coefficient (CCC) as an alternative. CONCLUSION: We provide recommendations that will enhance validity checks of microarray experiments while minimizing the need to run a large number of labour-intensive individual validation assays

Thin Bondline Measurement of Adhesively Bonded Metallic Aircraft Structures using an Ultrasonic Analyzer

The use of adhesive bonding for the assembly of aircraft structure is desirable because of the associated benefits of reduced weight, decreased parts count and increased fatigue life. The inability to fully characterize the nature of the bondline has been a limiting factor in applying this technology to the manufacture of primary aircraft structure. One such obstacle is the resolution limitation that has existed for the non-destructive measurement of bondline thicknesses. Up to the present time, ultrasonic methods have been limited in practice to a resolution approximately equal to the wavelength of the energy pulse employed. For a 15 MHz transducer, the highest frequency generally incorporated into off-the-shelf inspection equipment, this equates to a lower measurement limit of about 0.006″. For the FM-73 adhesive system used in this investigation, the acoustic velocity is 90, 600 inches per second [1]. The lower resolution limit will vary somewhat as a function of this speed. This limitation presented a problem because previous research had shown that the lap shear strength of aluminum bonded structure was maximized in bondlines between 0.002″ and 0.006″[2]. Furthermore, for bondlines of less than 0.002″, the lap shear strengths dropped off dramatically as illustrated in figure 1. The data presented is for elevated service temperature for an aircraft application. The trend shown is equally as valid for room temperature and at -67 degrees Fahrenheit. Clearly then, to guarantee the manufacture of a high strength, minimum weight structure while still assuring that a sufficient quantity of adhesive was present, it was necessary to establish a non-destructive inspection process, usable in production, that could quickly and accurately discern bondlines in the 0.002–0.006″ range.</p