Interactions Among Elaborative Interrogation, Knowledge, and Interest in the Process of Constructing Knowledge From Text.

The authors examined the impact of elaborative interrogation on knowledge construction during expository text reading, specifically, the interactions among elaborative interrogation, knowledge, and interest. Three measures of learning were taken: recall, inference, and coherence. Elaborative interrogation affected all aspects of learning measured, with a significant interaction between elaborative interrogation and interest with regard to inference. The experimental effect on the measure of inference was larger for the students who had less interest than for the students who had more interest. There was also an interaction effect between knowledge and elaborative interrogation for coherence. The experimental effect on coherence was higher for students who had less knowledge than students who had more knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conversion disorder and its subtypes: a need for a reclassification

Four subtypes of conversion disorder were described in DSM-IV. There are few publications concerning studies aimed at separating the subtypes of the conversion disorder. Usually, pseudoseizures are in focus and attempts are made to differentiate these seizures from other disorders. The aim of the present study has been to investigate differences between the four subtypes of the conversion disorder and to discuss the possibilities for a reclassification. Ninety-five patients were seen by two researchers and diagnosed as conversion disorders. The subtypes were determined according to DSM-IV criteria. All completed the Patients Information Form, developed by the researchers, and the Dissociative Experience Scale (DES). Twenty-four (25.2%) of the patients had motor symptoms or deficits (Type 1), 5 (5.2%) sensory symptoms or deficits (Type 2), 23 (24.2%) seizures or convulsions (Type 3) and 43 (47.3%) had mixed presentations (Type 4). There were statistically significant differences between the subtypes as concerns occupation, family history of psychiatric disorders, hospitalizations and place of settlement. Furthermore, the DES scores were statistically different between the groups of patients with different subtypes of conversion disorder.     

A patient with extra-adrenal retroperitoneal paraganglioma and review of the literature

Paragangliomas can arise from virtually any site in the body containing embryonic neural crest tissue. We present a female patient with an extra-adrenal retroperitoneal paraganglioma, and a review of the literature.     

Electrochemical determination of HIV drug Abacavir based on its reduction

Abacavir (I), a drug used in the treatment of HIV, is electrochemically reduced at the dropping mercury electrode in a four-electron process, similar to structurally related adenine (III) and adenosine triphosphate (IV). To undergo the reduction, the species is protonated in the vicinity of the electrode. The protonations take place on the 6-amino group and on one of the pyrimidine ring nitrogens. The role of covalent hydration of the pyrymidine ring has been interpreted. Best suited as supporting electrolytes for analytical purposes are solutions of 0.1-1.0 M sulfuric, perchloric, or hydrochloric acids. Procedures of analyses of tablets containing I were established and validated, based on peak currents obtained by linear sweep, differential pulse, or square-wave voltammetry with a hanging mercury drop electrode as indicator electrode. The procedure proved to be more sensitive and more reliable than that based on oxidation on a glassy carbon electrode, proposed previously.     

Enzyme-linked amperometric electrochemical genosensor assay for the detection of PCR amplicons on a streptavidin-treated screen-printed carbon electrode

A general purpose enzyme-based amperometric electrochemical genosensor assay was developed wherein polymerase chain reaction (PCR) amplicons labeled with both biotin and fluorescein were detected with peroxidase-conjugated antifluorescein antibody on a screen-printed carbon electrode (SPCE). As a proof of principle, the response selectivity of the genosensor was evaluated using PCR amplicons derived from lolB gene of Vibrio cholerae. Factors affecting immobilization, hybridization, and nonspecific binding were optimized to maximize sensitivity and reduce assay time. On the basis of the background amperometry signals obtained from nonspecific organisms and positive signals obtained from known V. cholerae, a threshold point of 4.20 microA signal was determined as positive. Under the optimum conditions, the limit of detection (LOD) of the assay was 10 CFU/mL of V. cholerae. The overall precision of this assay was good, with the coefficient of variation (CV) being 3.7% using SPCE and intermittent pulse amperometry (IPA) as an electrochemical technique. The assay is sensitive, safe, and cost-effective when compared to conventional agarose gel electrophoresis, real-time PCR, and other enzyme-linked assays for the detection of PCR amplicons. Furthermore, the use of a hand-held portable reader makes it suitable for use in the field.     

Transient Head Development due to Flood Induced Seepage under Levees

The purpose of this study was to predict the uplift force during floods on confining layers that overlay extensive horizontal confined aquifers that intersect a large river in response to the water level changes that occur with time in a flooding river. Transient flow of water through the confined aquifer was described by a diffusion type of equation with a boundary condition at the river in which the river head varied with time. The transient head distribution developed from the unsteady flow model applied to the aquifer was compared with the hydraulic head distributions obtained from U.S. Army Corps of Engineers steady-state flow model and a finite-element seepage model. This study concluded that the transient flow model has the potential to analyze time lag in head development, and to predict the seepage condition and heaving potential at various times and distances landside of a levee during a flood cycle, but additional case histories are needed to justify widespread use of the model.     

Olivine catalysts for methane- and tar-steam reforming

The removal of tar and lower hydrocarbons is a vital technological barrier hindering the development of biomass gasification. The present work evaluates four olivine catalysts (three untreated of different origin and one calcined) for lowering the amount of these compounds in biomass derived syngas by reforming model compounds (naphthalene, toluene, and methane). Treatments prior to reaction were shown to largely impact the catalytic activity and physiochemical properties of the olivine catalysts depending on its origin. The formation of free Fe phases following decomposition of a Fe-bearing serpentine phase ((Mg,Fe)₃Si₂O₅(OH)₄) near the surface of untreated olivine catalysts proved most important for facilitating higher activity compared to olivine catalysts with little or no serpentine phase initially. The most active catalyst was efficient at naphthalene removal (90% conversion at 800 °C), but more active catalysts are needed for applications where methane removal is required. Additionally, carbon deposition during naphthalene-steam reforming as well as Fe clustering during naphthalene-steam reforming and exposure to reducing conditions suggested stability may be a liability.     

Multisegment nanowire sensors for the detection of DNA molecules

We describe a novel application for detecting specific single strand DNA sequences using multisegment nanowires via a straightforward surface functionalization method. Nanowires comprising CdTe-Au-CdTe segments are fabricated using electrochemical deposition, and electrical characterization indicates a p-type behavior for the multisegment nanostructures, in a back-to-back Schottky diode configuration. Such nanostructures modified with thiol-terminated probe DNA fragments could function as high fidelity sensors for biomolecules at very low concentration. The gold segment is utilized for functionalization and binding of single strand DNA (ssDNA) fragments while the CdTe segments at both ends serve to modulate the equilibrium Fermi level of the heterojunction device upon hybridization of the complementary DNA fragments (cDNA) to the ssDNA over the Au segment. Employing such multisegment nanowires could lead to the fabrication more sophisticated and high multispecificity biosensors via selective functionalization of individual segments for biowarfare sensing and medical diagnostics applications.     

The characterization and differentiation of higher plants by fourier transform infrared spectroscopy

Several techniques have been used to identify and classify plants. We proposed Fourier transform infrared (FT-IR) spectroscopy, together with hierarchical cluster analysis, as a rapid and noninvasive technique to differentiate plants based on their leaf fragments. We applied this technique to three different genera, namely, Ranunculus (Ranunculaceae), Acantholimon (Plumbaginaceae), and Astragalus (Leguminoseae). All of these genera are angiosperms and include a large number of species in Turkey. Ranunculus and Acantholimon have ornamental importance, while Astragalus is an important pharmaceutical genus. The FT-IR spectra revealed dramatic differences, which indicated the variations in lipid metabolism, carbohydrate composition, and protein conformation of the genera. Moreover, cell wall polysaccharides including diverse groups could be identified for each genus. Acantholimon was found to have the highest hydrogen capacity in its polysaccharide and proteins. A higher lignin content and a lower occurrence of decarboxylation and pectin esterification reactions were appointed for Ranunculus and Astragalus compared to Acantholimon. All these results suggested that FT-IR spectroscopy can be successfully applied to differentiate genera, as demonstrated here with Ranunculus, Astragalus, and Acantholimon. In addition, we used this technique to identify the same species from different geographical regions. In conclusion, the current FT-IR study presents a novel method for rapid and accurate molecular characterization and identification of plants based on the compositional and structural differences in their macromolecules.