The development of sibling relationships in infancy: a short-term longitudinal study

24 infants and their preschool-aged siblings were observed in a laboratory playroom in the presence of their parents. Observations took place when the infants were 12 months old and again 6 months later. Analysis of the social behavior revealed that, at both ages, the children assumed differentiable roles in their interactions: The infants "followed" by observing and imitating while the preschoolers "led" by drawing the infants' attention and by assertive dominance. Over time, infants became increasingly willing to direct social behaviors toward their siblings. There was remarkable behavioral stability across time, with the infants' early propensities seemingly causally related to later pre-schoolers' behavior. Older girls directed more social behaviors to siblings than boys did. The amount of parent-directed behavior was affected by the number of adults present, whereas the amount of sibling-directed behavior was unaffected.     

The turnover and distribution of labelled corticosterone during post-natal development of the duckling (Anas platyrhynchos)

During 6 months of post-natal development in the laboratory, the weight of the adrenal gland relative to body weight decreases exponentially. In the 3 day-old duckling a single intravenous dose of labelled corticosterone becomes distributed in a very large apparent volume and an "extracellular" pool that is greater than the extracellular fluid volume and the pattern of disappearance of labelled hormone from plasma is biphasic. Later during development the volumes of distribution decrease and the biphasic pattern of disappearance becomes less distinct until at 6 months only one phase of disappearance can be detected with confidence. No significant change in plasma corticosterone concentration occurs during this period of development in the laboratory. Estimations of the corticosterone secretory rates, however, indicate that whereas the adrenal weight-specific rate os secretion increases during the first 3 weeks and declines therafter, the bodyf weight-specific secretory rate continues to decline throughtout the period of increasing body weight.     

对一次高频保护跳闸事故的分析

在一次系统故障过程中。输电线路的两套高频保护装置CSL-101B型和LFP-901B型动作行为不一致。本文就此展开分析，以达到正确理解两种保护动作行为的目的。并对加强高频保护的现场管理提出意见。     

DEVELOPMENT TOOL FOR COMPUTER VISION SYSTEMS AT PIXEL LEVEL

This paper describes a tool to aid the development of computer vision applications for pixel-level diagnosis. A conceptual framework for constructing pixel processors is described. The proposed tool is based on two domains: one deals with numerical images, named features, and the other deals with symbolic images, named classes. A reduced set of image and operator types is defined. Based on it, an object-oriented language is described. The main objects define features and classes and their associated operators, namely procedures, classifiers, and rules. All system control is goal oriented and is designed to provide symbolic images as results when a request is received from a higher level of the image understanding system. Some knowledge engineering concepts, such as certainty control and instances, are also included.     

己二酸的清洁催化氧化合成研究进展

综述了近年来以环己烯、环己酮、环己醇或环己烷等作原料,以过氧化氢或氧气等为氧源,采用不同的催化体系清洁合成己二酸的新进展.指出:在这些方法中,改性的分子筛及负载型催化剂-双氧水体系将是今后己二酸清洁合成的重点研究方向.     

湖北省蔬菜产业现状与加工业发展建议

文章从区位优势、产业特色和生产水平等特点出发,阐述湖北蔬菜产业的发展现状,剖析其蔬菜产业发展的制约因素,客观分析其蔬菜加工业存在的主要问题,提出全面实施质量标准体系、完善质量卫生安全检测体系、发展蔬菜贮藏保鲜技术和加工工艺等,以促进湖北蔬菜加工产业的可持续健康发展。     

EPR studies of (Bi, Pb)-2223 phase substituted by Ruthenium ions

This work studied X-ray powder diffraction (XRD), electrical resistivity and electron paramagnetic resonance (EPR) measurements for Bi_1.8Pb_0.4Sr₂Ca_2.1Cu_3−xRu_xO_10+δ (0.0 ≤ x ≤ 0.4) superconducting samples. XRD analysis and electrical resistivity data showed that the low-content of Ru, x ≤ 0.05, enhanced both the phase formation and the superconducting transition temperature of (Bi, Pb)-2223 phase. A phase change from (Bi, Pb)-2223 phase to (Bi, Pb)-2212 phase was reported for x ≥ 0.15. Two EPR lines were observed for 0.0 ≤ x ≤ 0.075, indicating the presence of both (Bi, Pb)-2223 and (Bi, Pb)-2212 phases. While, one EPR line was observed for x ≥ 0.15, corresponding to the (Bi, Pb)-2212 phase formation. The number of spins (N) participating in the resonance and its spin paramagnetic susceptibility (χ), for the two phases, were calculated as a function of both Ru-content and temperature. In addition, we reported the variation of activation energy (E_a), Curie constant (C), Curie temperature (θ) and effective magnetic moment (μ) with Ru-content.     

High avidity CTLs for two self-antigens demonstrate superior in vitro and in vivo antitumor efficacy

A majority of the human tumor-associated Ags characterized to date are derived from nonmutated "self"-proteins. Little is currently understood about the nature of the self-reactive lymphocytes that recognize these Ags. We recently characterized two nonmutated tumor-associated Ags for the B16 murine melanoma: tyrosinase-related protein-2 (TRP-2) and the endogenous retroviral envelope protein, p15E. We previously reported that both TRP-2 and p15E reactive CTL could be detected in the spleens of naive animals after a single in vitro stimulation using 10(-5)-10(-6) M of the appropriate Kb-binding 9-amino acid epitope. In this report we show that the CTL found in naive animals are low avidity lymphocytes, that respond only to high concentrations of peptide in vitro. We demonstrate that titration of in vitro-stimulating peptide to limiting concentrations distinguishes qualitative differences in the lymphocyte reactivity to these two Ags between vaccinated and unvaccinated animals. We further demonstrate that in vitro expansion of CTL in either high or low concentrations of stimulating peptide generated CTL cultures with different avidities for the relevant epitopes. CTL expanded in low concentrations demonstrated higher avidity for peptide-pulsed targets and better tumor recognition, when compared to CTL generated in the presence of high concentrations of Ag. More importantly, high avidity CTL demonstrated superior in vivo antitumor activity. These results demonstrate that qualitative differences in the CTL that recognize these two self-Ags are critically important to their in vitro and in vivo anti-tumor efficacy.     

Prediction of anticoagulation during hemodialysis by population kinetics and an artificial neural network

All systems currently used for routine hemodialysis require heparin administration to prevent blood clotting in the extracorporeal circuit. We tested the hypothesis that population-based statistical techniques can be used to predict heparin concentrations during routine hemodialysis. Two predictive models were developed, one based on nonlinear mixed effects modeling (NONMEM) and the other on a multilayer perceptron neural network. Serial clotting time data were obtained from forty-nine patients and used to develop the models. The models were used to predict the clotting times of 70 patients in a prospective test. We determined that the neural network provided greater precision, had fewer outliers in its predictions, and did not have the model misspecification in bolus administration that the NONMEM predictions demonstrated. A final NONMEM model was developed using all data from 119 patients to identify important covariates for predicting the heparin pharmacodynamic parameters, volume of distribution, and clearance. Both the volume of distribution and clearance increased following the initiation of dialysis and as the patient's baseline clotting time increased. The volume of distribution also increased as the patient's weight increased but was decreased by smoking and diabetes. Population-based statistical techniques may provide a useful alternative to existing methods for prescribing heparin.