边缘接入智能化

MMAP(多功能、多业务接入平台)集成了光纤传输和接入技术,使接入网和城域网(MAN)融合在一起。     

Evaluating performability: Most probable states and bounds

The number of states examined by most probable state algorithms for performability computations can be reduced dramatically by incorporating simple connectivity-based bounds, even when the performability measure is much more complex than connectivity. Modifications to Yang and Kubat's most probable state method are presented that permit the use of simple auxiliary bounds with only a small effect on the time per iteration. Computational results for a variety of performability measures are given.     

Book reviews

BT Environment City Bulletin: The Big Picture - all eight topics under one roof Edited by C. Wood, 1994, Lincoln, The Wildlife Trusts, 110pp., £19.00 for local authorities, £14.00 for local businesses, £9.00 for voluntary groups.

Theme Parks, Leisure Centres, Zoos and Aquaria Anthony and Patricia Wylson, 1994, Harlow, Longman, 183pp. ISBN 0 582 09928 5, hb £60.00

The Picturesque Landscape: Visions of Georgian Herefordshire Edited by Stephen Daniels and Charles Watkins, 1994, Department of Geography, University of Nottingham, 100pp. ISBN 0 85358 033 2, £7.50

The Countryside Ideal: Anglo-American Images of Landscape Michael Bunce, 1994, London, Routledge, 232pp. ISBN 0 415 10435 1

Ordering Space: Types in Architecture and Design Karen A Frank and Lynda H Schneekloth (eds.), 1994, New York, Van Norstrand Reinhold, 383pp ISBN 0 442 01233 0, pb £34.50     

Real time signal processing in the clinical setting

We routinely use a variety of real time signal acquisition, enhancement, and display techniques in the operating room to provide the surgeon with functional information. This enables reduction of surgical morbidity in cases which present a significant risk to the nervous system. Here we present regression based signal processing algorithms which produce considerable signal-to-noise-ratio enhancement with corresponding reduction in the time required to obtain an interpretable neurophysiological signal. We also present the approach we have applied to fault tolerance and distributed data display for our workstation cluster environment.     

Complications resulting from saphenous vein patch graft after carotid endarterectomy

OBJECTIVE: Reducing surgical risks to the minimum in carotid endarterectomy has become crucial, especially with the results of recent clinical trials extending indications to asymptomatic patients. The use of the saphenous vein patch graft (SVPG) has been suggested to reduce early postoperative thrombosis and cerebral infarct as well as late recurrent stenosis. However, the exact risks and complications involved in this technique are not known. METHODS: During a 23-year period (1972-1994), 2888 carotid endarterectomies with SVPG for primary carotid stenosis were performed by the Neurosurgical Cerebrovascular Service at the Mayo Clinic. The data from all patients were retrospectively analyzed, emphasizing postoperative complications related to SVPG. RESULTS: There were five postoperative vein ruptures (0.17%), four cases of aneurysm formation, and three cases of deep infection necessitating surgical intervention. The vein patch ruptured in one male patient and four female patients (mean age, 69 yr). All ruptures occurred within 4 days of the primary operation, including two during the first 24 hours. All patients with rupture underwent emergency surgery and were found to have intact suture lines and tears in the middle of the grafts. Two patients recovered without deficits, one suffered major disability, and the other two died. Aneurysm of the patch developed in two male patients and two female patients (mean age, 71 yr). All of the patients developed painless pulsatile neck masses 1 to 9 years after the initial surgery; two also had recurrent ischemic symptoms. All of the patients with aneurysms underwent surgical correction without consequences. CONCLUSION: Although the benefit of routine use of SVPG in carotid endarterectomy is still the focus of debate, this analysis showed that its use adds a small but definite risk of serious complications related to inherent weakness of the venous tissue. If a surgeon chooses to use a patch graft, our recommendation is for use of a synthetic material rather than vein.     

Recent achievements in the development of partitioning processes of minor actinides from nuclear wastes obtained in the frame of the NEWPART European programme (1996–1999)

Partitioning of long-lived minor actinides (americium and curium) from the nuclear wastes issuing the reprocessing of nuclear spent fuels, in order to transmute them into short-lived nuclides or to condition them into stable crystalline matrices, was the subject of intense research within the NEWPART research program of the European 4^th Frame Work Program, FWP (1996–1999). The target waste considered was the acidic raffinate (HAR) issuing the reprocessing of the used nuclear fuels by the PUREX process. A two step separation process based on liquid-liquid extraction was designed. The first step consists in the co-separation of the mixture of trivalent actinides and lanthanides from the HAR by extraction with a malonamide extractant (DIAMEX process), while the second step concerns the actinides(III)/lanthanides(III) group separation (SANEX process). Several DIAMEX and SANEX processes were developed and successfully tested with cold, spiked and genuine high active effluents. The research carried out also included basic and fundamental works in order to better understand the relationships between the structures of the extractants and their affinities for the target metal ions. The lecture highlighted both the basic and applied aspects of the research. This work will be pursued (PARTNEW program) within the 5^th FWP of the European Union during the period 2000–2003.     

Why some capuchin monkeys (Cebus apella) use probing tools (and others do not).

Tufted capuchins (Cebus apella) were provided with a task that facilitated the use and modification of sticks as probing tools. It was found that subjects aged 10 years or older at initial task exposure were less likely to use tools than were younger subjects. Furthermore, juveniles whose mothers died before the subjects were aged 3 years were less likely to use tools than were juveniles whose mothers survived through this period. The ability to use tools was not related to subject sex or to access to the tool site or raw tool materials. Subjects modified tools both before and during their use, and the relative percentage of tools modified increased with subject age. Thus, it appears that capuchins most readily acquire tool use before the age of 10 years and that early disruption of the mother–infant relationship has deleterious effects on the emergence of instrumental behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multisystemic Treatment: A Meta-Analysis of Outcome Studies.

Multisystemic treatment (MST) is a family- and home-based therapeutic approach that has been found to be effective in treating antisocial youths and that has recently been applied to youths with serious emotional disturbances. In light of the increasing dissemination of MST, this review examines the effectiveness of MST by quantifying and summarizing the magnitude of effects (treatment outcomes) across all eligible MST outcome studies. Included in a meta-analysis were 7 primary outcome studies and 4 secondary studies involving a total of 708 participants. Results indicated that across different presenting problems and samples, the average effect of MST was d = .55; following treatment, youths and their families treated with MST were functioning better than 70% of youths and families treated alternatively. Results also showed that the average effect of MST was larger in studies involving graduate student therapists (i.e., efficacy studies; d = .81) than in studies with therapists from the community (i.e., effectiveness studies; d = .26). In addition, MST demonstrated larger effects on measures of family relations than on measures of individual adjustment or peer relations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nitric oxide inhibition in an ovine model of heart failure

1. The role of nitric oxide (NO) in congestive heart failure was investigated by studying the acute haemodynamic, hormonal and renal effects of N(G)-monomethyl-L-arginine (L-NMMA(, a nitric oxide inhibitor, given as incremental bolus doses in six sheep before (normal) and after induction of heart failure (HF) by rapid left ventricular pacing (LVoff+). 2. 6-NMMA caused significant initial dose-dependent rises in left ventricular systolic pressure, mean arterial pressure (MAP), peripheral resistance (PR) and left atrial pressure and declines in cardiac output in both normal and HF states (maximum response in 2-6 min). These responses were all but abolished when L-arginine was given concurrently with L-NMMA. The dose-response curve for the L-NMMA-induced rise in MAP was shifted to the right following LVP (P < 0.05), which is consistent with previous observations of blunted NO synthase activity in HF. A subsequent decline in MAP and PR to below prebolus levels was observed 30-60 min after L-NMMA administration in the paced state. No significant hormonal or renal effects were observed. 3. In conclusion, the present study confirms the important haemodynamic role played by endogenous NO in the normal state and demonstrates a blunted pressor response to NO inhibition in this model of heart failure.