Rejection sensitivity and children's interpersonal difficulties

Some children respond to social rejection in ways that undermine their relationships, whereas others respond with more equanimity. This article reports 3 studies that test the proposition that rejection sensitivity--the disposition to defensively (i.e., anxiously or angrily) expect, readily perceive, and overreact to social rejection--helps explain individual differences in response to social rejection. Data were from urban, minority (primarily Hispanic and African American) fifth to seventh graders. Study 1 describes the development of a measure of rejection sensitivity for children. Study 2 provides experimental evidence that children who angrily expected rejection showed heightened distress following an ambiguously intentioned rejection by a peer. Study 3 shows that rejection sensitive children behaved more aggressively and experienced increased interpersonal difficulties and declines in academic functioning over time.     

Effects of interferon inducers on chemically-induced mutagenesis and carcinogenesis

The in vitro study on an isolated system of myocardial contractile proteins determined optimal concentrations of the positive inotropic action and biological activity ranges of beta-methyldigoxin (beta-MD), strophanthin K, K-strophantozide, beta-acetyldigoxin (beta-AD), milrinone, and amrinone. Optimal concentrations of the beta-MD and strophanthin K (10(-2) and 10(-6) M, respectively) significantly increased qualitatively and quantitatively the economy and thermodynamic efficiency, altered the energy transformation in the contractile protein system under the isometric contraction, whereas the beta-AD produced only the quantitative effect. However, the beta-MD and strophanthin K at concentrations exceeding the optimal one by one order lost the ability to produce the qualitative effect, retaining only the quantitative one in the actomyosin ensemble. The strophanthin K significantly increased the economy of a single actomyosin ensemble in the force generation phase and the beta-MD in the tension maintenance phase. Unlike the strophanthin K, the beta-MD did not slow down (did not worsen) the relaxation process. This provides grounds to conclude that the beta-MD produces most favorable effect on the energy transformation by myocardial contractile proteins.     

HEAT TRANSFER IN SPOUTED BEDS

Experiments were carried out in order to analyse the wall-to-bed and fluid-to-particle heat transfer coefficients in spouted Beds. wall-to-bed heat transfer coefficients were determined in cylindrical-conical and conical spouted beds for various gas flow rates, particle sizes and bed heights for spouted beds with and without draft tubes.

A new definition for wall-to-bed transfer coefficient was proposed baaed on experimental observations.

The heat tranefer area was also studied to ensure that a physically significant fluid-to-particle heat transfer coefficient was achieved.     

Identification of material properties of composite plate specimens

An indirect identification technique to predict the mechanical properties of composite plate specimens is presented. This technique makes use of experimental eigenfrequencies, the corresponding numerical eigenvalue evaluation, sensitivity analysis and optimization. The laminate analysis is formulated in terms of non-dimensional material parameters and the discrete model is based on the linear shear deformation theory of Mindlin. The constrained minimization of an error functional expressing the difference between measured higher frequencies of a plate specimen and the corresponding numerical ones is then carried out to find the desired optimum parameters. The required sensitivities with respect to changes in the non-dimensional material parameters have the option of being evaluated analytically, semi-analytically or alternatively by finite difference. Results which show the validation of the sensitivities and the limitations of the model to predict the required quantities and its range of application and accuracy are demonstrated through test cases.     

Inhibitory effect of crocetin on intracellular nucleic acid and protein synthesis in malignant cells

The possibility that dietary intake of diverse naturally occurring compounds may influence the occurrence of cancer is receiving considerable scientific attention. Previously, it was reported that an extract (Crocus sativus), which contains carotenoids, had an antitumor effect and inhibited colony formation and nucleic acid synthesis by malignant human cells. Epidemiological and experimental research has indicated that carotenoids might act as antitumor agents. We have studied crocetin, a carotenoid isolated from saffron, which has been shown to have biological activity. In our experiments we utilized three malignant human cell lines: HeLa (cervical epitheloid carcinoma), A549 (lung adenocarcinoma) and VA13 (SV-40 transformed fetal lung fibroblast) cells. The effect of crocetin on colony formation and cellular DNA, RNA and protein synthesis in these cells has been examined. Incubation of these cells with crocetin for 3 h caused a dose-dependent inhibition of nucleic acid and protein synthesis. Crocetin also had a dose-dependent inhibitory effect on DNA and RNA synthesis in isolated nuclei and suppressed the activity of purified RNA polymerase II.     

Sudden death in athletes

Identifying all athletes at risk for exercise-related sudden death is difficult because systematic reliable screening is expensive. Nevertheless, if a perfect screening method existed, an appreciable number of athletes at increase risk for sudden death would not be identified. We think that a careful history designed to identify symptomatic athletes and a rigorous family history of congenital heart disease may be the most practical screening method.     

Al,Al/C and Al/Si implantations in 6H-SiC

Multiple-energy Al implantations were performed with and without C or Si coimplantations into 6H-SiC epitaxial layers and bulk substrates at 850°C. The C and Si co-implantations were used as an attempt to improve Al acceptor activation in SiC. The implanted material was annealed at 1500, 1600, and 1650°C for 45 min. The Al implants are thermally stable at all annealing temperatures and Rutherford backscattering via channeling spectra indicated good lattice quality in the annealed Al-implanted material. A net hole concentration of 8 × 10¹⁸ cm⁻³ was measured at room temperature in the layers implanted with Al and annealed at 1600°C. The C or Si co-implantations did not yield improvement in Al acceptor activation. The co-implants resulted in a relatively poor crystal quality due to more lattice damage compared to Al implantation alone. The out-diffusion of Al at the surface is more for 5Si co-implantation compared to Al implant alone, where 5Si means a Si/Al dose ratio of 5.     

Spectral analysis of electrocardiogram signals of the isolated guinea pig heart for the detection of arrhythmias

Fast Fourier Transform analysis of the electrocardiogram (ECG) signal of the isolated guinea pig heart has been used to investigate the subtle ECG changes that precede cardiac arrhythmias. During prolonged periods of regular contractile activity, spectral analysis of the isolated guinea pig heart ECG revealed that the major frequency components were evenly distributed over the range 0-64 Hz. Prior to arrhythmias or during ischaemia however, there was a major reduction in the amplitude of the higher frequency components. Thus, Fast Fourier Transform analysis of an ECG record enables the detection of the subtle ECG configuration changes that precede cardiac rhythm disturbances. The potential application of this technique for the prediction of cardiac arrhythmias is discussed.     

The nature and use of purified insulins

The limited availability of highly purified insulin preparations for the treatment of diabetes mellitus in australia since 1975, has prompted a review of their history, clinical use and potential in the treatment of diabetics receiving insulin.