Interparental conflict, children's social cognitions, and child aggression: A test of a mediational model.

Although correlations between interparental conflict and child maladjustment are well-established, the processes connecting these 2 phenomena are less understood. The present study tested whether an aggressogenic cognitive style mediates the relationship between interparental conflict and child aggression. A multiethnic sample of 115 families with a child between the ages of 7 and 13 years participated. Questionnaires were used to assess parents' and children's perceptions of interparental conflict, children's social problem-solving strategies and beliefs about aggression, and parent and teacher reports of child aggression. Support was found for the mediating effect of aggressogenic cognitions on children's school aggression but not on children's aggression at home. Implications for understanding the associations among interparental conflict, children's social cognitions, and child aggression in different environmental contexts are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structural Studies of the Superconducting La2.5Y0.5CaBa3(Cu1−xFex)7Oz (0 ≤ x ≤ 0.1) Perovskite System by Neutron Diffraction

We have investigated the effect of Fe substitution on the structural and superconducting properties of La_2.5Y_0.5CaBa₃(Cu_1?x Fe _x )₇O _z system by Rietveld refinement of the neutron diffraction patterns of three samples with x = 0.02 (labelled B₁), x = 0.06 (B₂), and x = 0.10 (B₃) along with X-ray diffraction, resistivity, AC susceptibility, and oxygen-content measurements. Samples B₁, B₂, and B₃ are superconducting with T _c ^R=0 values of 73, 62, and 41 K, respectively. Neutron diffraction studies confirm (i) the formation of a single phase tetragonal structure (space group P4/mmm) for all three samples, (ii) Ca and Y ions substitution at the La site concomitantly displaces La onto Ba sites, and (iii) increasing x from 0.02 to 0.10 increases oxygen content (the amount of oxygen per unit cell), as well as Cu(1)— O(4) and Cu(1)— O(1) bond lengths whereas Cu(2)— O(4) bond length decreases with corresponding decrease in T _c to 41 K due to increasing occupancy of Fe ions at Cu(2) site. The change in bond lengths with oxygen content are essentially the same as those of Fe content (x). Present studies establish a correlation between the bond lengths (Cu(1)— O(1), Cu(1)— O(4), and Cu(2)— O(4)) and the measured T _c values of three samples.     

Blood lead levels in preschool children in Rawalpindi

Blood lead levels were determined in preschool children residing in Urban areas of Rawalpindi city. Of 92 (50 males and 42 females) children aged one to 5 years were included in the study. Blood lead levels ranged from 7 micrograms/dl to 34 micrograms/dl (mean 18.8 micrograms/dl). The mean lead levels were slightly higher in males (20.3 micrograms/dl) than in females (17.2 micrograms/dl) and over 90% children had lead levels above the acceptable limit of 10 micrograms/dl. Use of leaded petrol, contaminated surma, leaded paints and pica in children are common in our country and may lead to increased lead levels and appropriate measures should be taken to control this trend.     

Countercation intercalation and kinetics of charge transport during redox reactions of nickel hexacyanoferrate

The dynamics of charge propagation in nickel hexacyanoferrate, a model metal-substituted analogue of Prussian Blue-type cyanide-bridged systems, was considered in electrolytes containing potassium and other alkali metal cations. The apparent (effective) diffusion coefficients for charge transport were determined using a large-amplitude potential-step chronocoulometry and small-amplitude potential-step chronocoulometric potentiostatic intermittent titration. The dependence of diffusion coefficient on the potential applied is consistent with the intercalation like model of the counter-cation sorption/desorption during redox processes of nickel hexacyanoferrate. Some differences in diffusion coefficients may originate from distinct charge densities (membrane properties) of the oxidized and reduced metal hexacyanoferrate structures. The existence of strong attractive interactions between an alkali metal cation and the cyanometallate matrix is also expected. The overall dynamics of charge propagation seems to be controlled by transport of electrolyte cations within the film rather than by electron self-exchange (hopping) between the mixed-valence hexacyanoferrate(III,II) ionic sites.     

Thermally controlled molecular disassembly of a crosslinked polymer network by the incorporation of sterically hindered urea linkages

Crosslinked polymer networks are excellent materials for multiple applications. However, although their crosslinked structure gives them many positive attributes, it also makes them intractable. Therefore, it is exceedingly difficult to reprocess crosslinked networks without exposure to extreme degradation conditions. In this work, we were able to create a crosslinked network that showed controlled disassembly upon stimulus. It was found that a controlled network disassembly process could be invoked by the incorporation of sterically hindered urea linkages into the polymer network. The network was shown to disassemble upon exposure to heat, whereas in the absence of heat, the network was found to maintain its crosslinked structure. The disassembly temperature could be varied by careful selection of the cleaving agent. This work focuses on showing the controlled network disassembly of a crosslinked polymer matrix as a function of temperature. Herein, we describe the factors that control the disassembly temperature and conclude with a possible mechanism for the disassembly process. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 856–864, 2002     

Experimental results of a supplementary technique for auto-reclosing EHV/UHV transmission lines

A technique to discriminate between the line charging inrush current and the current resulting on closing or auto-reclosing a faulted EHV/UHV transmission line has been implemented on a 32-b digital signal processor (DSP) board. The technique is based on the voltage signals before switching and the current signals. This technique is proposed to be a supplement to the main protection schemes for both single-circuit and double-circuit lines. The scheme is tested on a physical model of a transmission system with a source at each end. Laboratory tests show that the proposed technique is effective for three-pole and single-pole reclosing on a faulted or healthy line.     

MicroRNAs and their target mRNAs as potential biomarkers among smokers and non‐smokers with lung adenocarcinoma

Lung adenocarcinoma is one of the major causes of mortality. Current methods of diagnosis can be improved through identification of disease specific biomarkers. MicroRNAs are small non‐coding regulators of gene expression, which can be potential biomarkers in various diseases. Thus, the main objective of this study was to gain mechanistic insights into genetic abnormalities occurring in lung adenocarcinoma by implementing an integrative analysis of miRNAs and mRNAs expression profiles in the case of both smokers and non‐smokers. Differential expression was analysed by comparing publicly available lung adenocarcinoma samples with controls. Furthermore, weighted gene co‐expression network analysis is performed which revealed mRNAs and miRNAs significantly correlated with lung adenocarcinoma. Moreover, an integrative analysis resulted in identification of several miRNA–mRNA pairs which were significantly dysregulated in non‐smokers with lung adenocarcinoma. Also two pairs (miR‐133b/Protein Kinase C Zeta (PRKCZ) and miR‐557/STEAP3) were found specifically dysregulated in smokers. Pathway analysis further revealed their role in important signalling pathways including cell cycle. This analysis has not only increased the authors’ understanding about lung adenocarcinoma but also proposed potential biomarkers. However, further wet laboratory studies are required for the validation of these potential biomarkers which can be used to diagnose lung adenocarcinoma.Inspec keywords: cancer, molecular biophysics, patient diagnosis, tumours, RNA, proteins, lung, genetics, medical diagnostic computing, molecular configurationsOther keywords: miRNAs expression profiles, mRNAs expression profiles, smokers, nonsmokers, integrative analysis, lung adenocarcinoma, microRNAs, disease specific biomarkers, noncoding regulators, genetic abnormalities, weighted gene coexpression network analysis     

Investigation of the morphological cell structures and their optical significances of Aeshna cyanea

The transparent wing of the dragonfly Aeshna cyanea has been investigated using scanning electron microscopy (SEM), optical microscopy (OPM), energy‐dispersive X‐ray spectroscopy (EDS) and reflectance spectroscopy. Four cells (D1–D4) were studied and classified according to their general morphology. The OPM depicted the vein‐joint characterised by the distribution of resilin. EDS technique showed common elements such as carbon, oxygen, and chlorine. SEM analysis revealed thin membranes reinforced with a network of hallow veins. Spikes and round shape of microstructures were identified. The roughness of the pruinosity was estimated, which indicates the shape and curvature of the microstructures that essentially play a significant role in the optical response observed. The study can be essential to design and improve micro‐air vehicles.Inspec keywords: bio‐optics, optical microscopy, biomembranes, light reflection, X‐ray chemical analysis, scanning electron microscopy, crystal microstructureOther keywords: transparent wing, EDS technique, SEM analysis, morphological cell structures, optical microscopy, dragonfly Aeshna cyanea, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, reflectance spectroscopy, vein‐joint characterization, resilin distribution, carbon, oxygen, chlorine, thin membrane reinforced hallow vein network, microstructure spikes, microstructure round shape, micro‐air vehicles     

Superconductivity in Y-Ba-Ca-Cu-O

The Y-Ba-Ca-Cu-O superconductor (Ca_0.2Y_0.3Ba_0.5CuO_3–z ) was prepared under different heat treatments and sintering conditions. Electrical resistance measurements from ambient temperature to 77 K show that four of the five samples were single-phase superconductors withT _c in the range 82 to 85 K. The X-ray diffraction measurements revealed an orthorhombic perovskite type structure for all samples.National Scientific Research and Development Board's Research Fellow.     

Malignant peripheral nerve sheath tumors. A clinicopathologic study of 28 cases

BACKGROUND: In order to improve management, the files and tissue sections of 28 cases of malignant peripheral nerve sheath tumors (MPNST) diagnosed at the University of Virginia Health Sciences Center between 1960 and 1990 were reviewed. METHODS: Clinical data tabulated included age, sex, race, the presence or absence of von Recklinghausen neurofibromatosis type 1 (NF-1), tumor size, tumor location, type of treatment, and status of surgical margins. Pathologic study included assessment of mitotic rate, divergent differentiation, cellular atypia, necrosis, and vascular reaction. RESULTS: The median disease-free survival time was 11 months, and the median overall survival time was 44 months. Overall survival and disease-free survival were significantly influenced by patient age, tumor location, tumor size, extent of surgery, and quality of margins. Patients with a family history of neurofibromatosis also had better disease-free survival. None of the other clinical variables correlated with survival. CONCLUSIONS: The authors recommended that patients with NF-1 be followed closely for MPNST development. For most cases, treatment should include aggressive surgery with wide surgical margins combined with adjuvant radiation therapy. Chemotherapy may have a role for treatment failures.