A methodology for multicriteria network partitioning

Conventional solution techniques are not appropriate for the multiobjective partitioning of large-scale distributed computer networks. The multiple (conflicting) goals and constraints include the assignment of all nodes without violating partition capacity limitations, maximal communication between nodes assigned to the same partition, minimal dispersion of technology classes, minimal diversity of technology classes within partitions, maximal reliability and minimal cost. This problem has been mathematically formulated and a two-stage, heuristic solution method was developed and programmed for solution and evaluation. The modelling and solution methodologies are flexible and may easily be applied to a wide range of network partitioning problems.     

为音频设备提供高性能的低通30kHz贝塞尔滤波器

贝塞尔(Bessel)线性相位滤波器正是由于具有向其截止频率以下的所有频率提供等量延时的特性,才被用于音频设备中,在音频设备中,必须在不损害频带内多信号的     

Human-robot interaction in rescue robotics

Rescue robotics has been suggested by a recent DARPA/NSF study as an application domain for the research in human-robot integration (HRI). This paper provides a short tutorial on how robots are currently used in urban search and rescue (USAR) and discusses the HRI issues encountered over the past eight years. A domain theory of the search activity is formulated. The domain theory consists of two parts: 1) a workflow model identifying the major tasks, actions, and roles in robot-assisted search (e.g., a workflow model) and 2) a general information flow model of how data from the robot is fused by various team members into information and knowledge. The information flow model also captures the types of situation awareness needed by each agent in the rescue robot system. The article presents a synopsis of the major HRI issues in reducing the number of humans it takes to control a robot, maintaining performance with geographically distributed teams with intermittent communications, and encouraging acceptance within the existing social structure.     

Peroxynitrite: a biologically significant oxidant

A prolongation of the intracellular acidosis after myocardial ischemia can protect the myocardium against reperfusion injury. In isolated hearts, this was achieved by prolongation of the extracellular acidosis. The aim of this study was to investigate whether regional reperfusion with acidotic blood after coronary artery occlusion can reduce infarct size and improve myocardial function in vivo. Anesthetized open-chest dogs were instrumented for measurement of regional myocardial function, assessed by sonomicrometry as systolic wall thickening (sWT). Infarct size was determined by triphenyltetrazolium staining after 3 h of reperfusion. The left anterior descending coronary artery (LAD) was perfused through a bypass from the left carotid artery. The animals underwent 1 h of LAD occlusion and subsequent bypass-reperfusion with normal blood (control, n = 6) or blood equilibrated to pH = 6.8 by using 0.1 mM HCl during the first 30 min of reperfusion (HCl, n = 5). Regional collateral blood flow (RCBF) at 30-min occlusion was measured by using colored microspheres. There was no difference in recovery of sWT in the LAD-perfused area between the two groups at the end of the experiments [-2.8+/-1.2% (HCl) vs. -4.4+/-2.5% (control); mean +/- SEM; p = NS]. RCBF was comparable in both groups. Infarct size (percentage of area at risk) was reduced in the treatment group (12.8+/-2.8%) compared with the control group (26.2+/-4.8%; p < 0.05). These results indicate that reperfusion injury after coronary artery occlusion can be reduced by a prolonged local extracellular acidosis in vivo.     

Sir Charles James Martin MB FRS: Australian serpents and Indian plague, one-hundred years ago

In 1891 as Demonstrator in Physiology at the University of Sydney, Charles Martin began the first systematic study of the chemical and physiological properties of the venoms of the Australian elapid species, Pseudechis porphyriacus and Notechis scutatus. Two major constituents were detected: a large coagulable protein which was associated with intravascular clotting, and a small proteinaceous molecule, an albumose, associated with neurotoxicity. Martin designed and constructed a high-pressure gelatin membrane ultrafilter for fractionation of venom. His studies indicated that certain physiological actions and clinical symptoms were related to the faster rate of diffusion within the tissue space of a neurotoxic constituent relative to a clotting constituent. Extending this work to toxin-antitoxin relationships, Martin provided evidence that antitoxin was a large molecule with slow diffusibility in tissue and advised the administration of curative serum (including diphtheria antitoxin) by intravenous injection. In 1903, Martin returned to London as Director of the Lister Institute of Preventive Medicine. He was soon involved in the planning of scientific work to be undertaken by the Commission for Investigation of Plague in India as the disease continued to ravage the subcontinent. Detailed epidemiological studies of possible factors involved in the spread of Pasteurella pestis showed, unequivocally, that infected rat fleas were the vector of transmission from rats to humans.     

Prognostic significance of B-lineage leukemic cell growth in SCID mice: a Children's Cancer Group Study

Primary leukemic cells isolated from children (N = 681 ) with newly diagnosed B-lineage ALL enrolled on risk-adjusted treatment protocols of the Children's Cancer Group (CCG) were injected via the tail vein into 7-10 week old SCID mice. Leukemic cells from 104 of 681 patients (15.3%) were able to engraft and proliferate in one or more SCID mouse organs. These SCID+ patients were somewhat more likely than SCID patients to be older than 10 years of age (p = 0.03) and have WBC counts >20,000/microL (p = 0.04), but the groups were similar with respect to all other presenting features. Event-free survival (EFS) outcome at 3 years of follow-up was similar for SCID+ patients compared with SCID- patients (79.2%, SD = 5. 1% vs. 84.8%, SD = 2.8%; p = 0.20). Overall survival also was similar between the two groups (p = 0.93). This result was maintained within the subgroups of lower risk (N = 448) and higher risk (N = 233) patients. However, there were trends for poorer outcome among patients whose cells caused overt leukemia in SCID mice and infiltrated either 6 or more organs (p = 0.03), skeletal muscle (p = 0.0003), kidney (p = 0.05), or spleen (p = 0.06). Thus, engraftment of primary leukemic cells in SCID mice was not a significant predictor of outcome for the aggregate population of B-lineage ALL patients, the majority of whom were low risk, treated according to contemporary intensive chemotherapy programs of the CCG. However, development of disseminated overt leukemia and infiltration of SCID mouse skeletal muscle by primary leukemic cells from adjacent bone marrow may reflect a biologically more aggressive disease and identify patients at higher risk for treatment failure.     

Psychological distress in blood donors notified of HTLV-I/II infection. Retrovirus Epidemiology Donor Study

BACKGROUND: Blood donations in the United States have been screened for antibody to human T-cell lymphotropic virus types I and II (HTLV-I/II) since November 1988. Although clinically diagnosed illness associated with HTLV-I/II remains relatively uncommon, blood donors notified of HTLV infection frequently report negative psychological and social effects following notification. STUDY DESIGN AND METHODS: To assess psychological outcomes, the General Well-Being Scale, a standardized 18-item questionnaire, was administered to 464 HTLV-I/II-positive donors and 91 sex partners at five blood centers in the United States following notification of HTLV-I/II infection. The questionnaire was also given to 735 HTLV-I/II-negative donors. RESULTS: Scores for donors seropositive for HTLV-I and HTLV-II showed significantly more psychological distress than did scores for seronegative donors (p < 0.0005) or a large national sample (p < 0.05). Both HTLV-I (p = 0.02) and HTLV-II (p = 0.01) seropositivity remained significant predictors of lower overall well-being scores after analysis controlling for race, age, gender, education, income, donation type, time since notification, self-reported health status, and intravenous drug use. Variables that predicted higher overall scores were negative HTLV status, older age, higher income, better health, fewer sick days, and fewer work limitations due to health problems. CONCLUSION: Increased psychological distress may be related to notification of HTLV infection among blood donors in the United States.     

Cognitive, psychosocial, and educational issues in neuromuscular disease

There is a broad range of cognitive function in persons with neuromuscular disease, both between and within the various types. Those groups exhibiting little or no cognitive impairment included FSHD, LGS, BMD, SMA, and HMSN. DMD and MD--particularly C-MD-groups did show deficits. The data on HSCA are too minimal to reach any firm conclusion at this time. Specific patterns of deficits in DMD have been proposed, but need further research. No specific correlates with diminished intellectual function have yet been found, and the search for a cause of the intellectual deficit has as yet been unsuccessful. Nevertheless, the impact of NMD on psychosocial and educational function of both children and adults is significant. It is recommended that supportive services be provided by medical professionals specifically trained in such helping professions as psychology to lessen the impact of these chronic progressive diseases and thus to improve the quality of life of persons with NMD.