IP组播的安全解决方案

简单介绍了IP组播的基本网络体系和潜在的应用,PIM-SM组播基本原理和特点,阐述了在实际的PIM-SM网络中一系列组播安全控制手段,包括防止RP欺骗、SA消息控制、组播发送授权控制、数据的安全性控制、用户安全认证等措施。     

Dosimetric support of the International Programme on the Health Effects of the Chernobyl Accident (IPHECA) pilot project: main results and problems

The problem of post-Chernobyl dosimetry is unique in its complexity in the history of radiation medicine and radiation protection. This is because the early experience of mass exposure of people (bombing of Hiroshima and Nagasaki, Windscale and South-Ural accidents, exposure of inhabitants of Nevada in the United States of America, the Semipalatinsk area in the former USSR, the Marshall Islands, and the Goi?nia accident in Brazil, and others) differed both in the much simpler structure of the irradiation source and in the number and characteristics of exposed persons. It is obvious that post-Chernobyl dosimetry, both as an independent problem, and as a tool for epidemiological studies, requires significant expertise and economic and technical expenditures. Extensive and deep research has been carried out in Ukraine for the past 10 years. This article reviews the main results of these studies.     

Design of four-helix bundle protein as a candidate for HIV vaccine

To be efficient, a synthetic vaccine should contain differentT and B cell epitopes of human immunodeficiency virus (HIV)antigens, and the B epitope regions in the vaccine and in theHIV should be conformationally similar. We have suggested previouslythe construction of vaccines in the form of a protein with apredetermined tertiary structure, namely a four--helix bundle.Antigenic determinants of cellular and humoral immunity areblocks for the vaccine design. From experimentally studied HIV-1T and B cell epitopes, we constructed a sequence of a four-helixprotein TBI (T and B cell epitopes containing immunogen). Thegene of the protein was synthesized and the protein was producedin C600 Escherichia coli cells under recA promoter from Proteusmirabelis. CD spectroscopy of the protein demonstrated that30% of amino acid residues adopt an -helical conformation. Miceimmunized with TBI have shown both humoral and cellular immuneresponses to HIV-1. The obtained data show that the design ofTBI was successful. The synthesized gene structure makes possiblefurther reconstruction and improvement of the protein vaccinestructure.     

Quality Control of Armor Fabric by Modeling Thermomechanical Processes under Projectile Impact

Mechanical and thermomechanical processes of interaction between a projectile and the multilayer woven barrier made of a polymer fabric are considered. A simplified mathematical model is proposed to describe the deceleration of the projectile due to the dissipation of energy spent on irreversible stretching deformation of fabric fibers, fiber slip friction, and barrier material heating. The parameters of governing equations are estimated by means of identification based on experimental data. Results of a computational experiment using the mathematical model can be employed for the diagnostics of armor protection based on the measurements of dynamic temperature fields.     

Comparison of two quantitative methods for the evaluation of neuronal number in the frontal cortex in Alzheimer disease

How to assess the substantial neuronal loss in a neurodegenerative disease such as Alzheimer disease is still being debated. Recently, stereological procedures have been proposed that claim improved accuracy and statistical power, but the results of some of these investigations have been controversial. In this study we compared and correlated the cell density results calculated per unit of volume obtained by a stereological technique, the "selector," with the cell counts per unit area obtained by computer-aided image analysis morphometry, in the same sections of midfrontal cortex in Alzheimer disease and control cases. The "selector" revealed a significant decrease in neuronal density that correlated well with a similar fall in large neuronal counts per unit area, as estimated by image analysis morphometry. These results indicate that stereological techniques and image analysis morphometry are complementary methods in reliably assessing cellular populations in neurodegenerative disorders.     

Dependence of microwave produced heating of cell suspensions on their concentration

This study compared three radionuclide techniques in distinguishing musculoskeletal infection from noninfectious inflammation. METHODS: Thirty-five orthopedic patients with suspected musculoskeletal infection were examined using three radionuclide techniques in sequence: triphasic bone scintigraphy, 99mTc radioleukocytes (99mTc-WBC) scintigraphy and 99mTc human immunoglobulin (99mTc-Hig) scintigraphy. Two "early" and "late" acquisitions were performed, at 4-6 hr and 20-24 hr postinjection, respectively. Patients who were diagnosed as suffering from noninflammatory lesions became the controls. We calcu"late"d for all studies one index of inflammation (Infl) as the ratio between counts in the uptake area and counts in an equal area of normal tissue. RESULTS: The "early" radiolabeled leukocytes and "late" Hig scintigraphy allowed the greatest ability to distinguish between infections and noninfectious inflammations (p < 0.011 and p < 0.016) with a sensitivity of 96.6% and 96.5% and specificity of 71% and 100%, respectively. Hig and radioleukocytes allowed distinguishing infections from noninflammatory diseases at both examinations. CONCLUSION: The "early" radioleukocyte scintigraphy allowed us to separate infections from noninfectious inflammations. In contrast, the same result can be obtained only with the "late" scan in the Hig study, but Hig mapped the spread of the inflammation into soft tissues better. Hig might be an alternative to radioleukocytes because of its simple preparation, similar accuracy and safety.     

Mental disorders in a pediatric clinic

In general pediatric clinic 262 children aged 1-15 years with functional hyperthermia, functional disorders of cardiac rhythm (extrasystole, paroxysmal and recurrent tachycardia), arterial hyper- and hypotension, autonomic dysfunctions were examined. 21 children with organic cardiac diseases were examined too. Mental disorders were revealed in all the cases: mono- and bipolar affective disorders (58.1%) as well as affective-dilutional (10.4%) states, primarily in the form of "masked" hypomanias, neurotic and neurotic-like (16.2%), psychopathic and psychopathic-like (7.0%), psychoorganic (3.7%) and epileptiform (4.6%) syndromes. The spectrum of mental disorders was extremely wide--from practical normal (in limits of reactions of personal accentuations or age crisis) to endogenic diseases. Combined treatment including drug therapy, psychotherapy and family correction was quite effective.     

Simple, robust linkage tests for affected sibs

Parametric-linkage analysis applied to large pedigrees with many affected individuals has helped in the identification of highly penetrant genes; but, for diseases lacking a clear Mendelian inheritance pattern or caused by several genes of low to moderate penetrance, a more robust strategy is nonparametric analysis applied to small sets of affected relatives, such as affected sib pairs. Here we show that the robustness of affected-sib-pair tests is related to the shape of the constraint set for the sibs' identity-by-descent (IBD) probabilities. We also derive a set of constraints for the IBD probabilities of affected sib triples and use common features of the shapes of the two constrain sets to introduce new nonparametric tests (called "minmax" tests) that are more robust than those in current use. Asymptotic-power computations support the robustness of the proposed minmax tests.