Bacillus anthracis: current knowledge in relation to contamination of food

In this article, information related to anthrax and its etiologic agent, Bacillus anthracis, in food is reviewed. The major topics discussed include the taxonomic relationship of B. anthracis to other Bacillus species, methods used for the recovery of the organism from surfaces and foods, routes of infection, the pathogenesis of the organism, the microbial ecology of the vegetative cell and spore in foods and the environment, chemical and physical treatments for spore inactivation, and the control of the disease in animals.     

Content-Centered Collaboration Spaces in the Cloud

Emphasizing communication, collaborative work, and community, the authors envision a cloud-based platform that inverts the traditional application-content relationship by placing content rather than applications at the center, enabling users to rapidly build customized solutions around their content items. The future of collaboration will focus on building and sustaining communities around content, tasks, and ideas. Hosted entities known as content spaces will support ecosystems of users and developers around this content. To make their case, the authors review the dominant trends in computing that motivate the exploration of new approaches for content-centered collaboration and discuss ways to address certain core problems for users and organizations.     

Comparison of steam and autothermal reforming of methanol using a packed-bed low-cost copper catalyst

Small-scale reformers for hydrogen production via steam and autothermal reforming of hydrocarbon feedstocks can be a solution to the lack of hydrogen distribution infrastructure. A packed-bed reactor is one possible design for such purpose. However, the two reforming processes of steam and autothermal methods have different characteristics, thus they have different and often opposite design requirements. In implementing control strategy for small-scale reformers, understanding the overall chemical reactions and the reactor physical properties becomes essential. This paper presents some inherent features of a packed-bed reactor that can both improve and/or degrade the performance of a packed-bed reactor with both reforming modes.The high thermal resistance of the packed bed is disadvantageous to steam reforming (SR), but it is beneficial to the autothermal reforming (ATR) mode with appropriate reactor geometry. The low catalyst utilization in steam reforming can help to prevent the unconverted fuel leaving the reactor during transient by allowing briefly for higher reactant fuel flow rates. In this study, experiments were performed using three reactor geometries to illustrate these properties and a discussion is presented on how to take advantages of these properties in reactor design.     

Outcome of moderate carotid artery stenosis in patients who are asymptomatic

PURPOSE: The incidence rate of disease progression and stroke after the diagnosis of a moderate (50% to 79%) carotid stenosis was determined by means of color-flow duplex scanning. METHODS: During a 4-year period, 344 male veterans with moderate internal carotid artery stenoses, on one or both sides, were examined at regular intervals for a mean period of 25 months. Carotid color-flow scans were obtained semiannually. Clinical follow-up was performed to determine the incidence rate of amaurosis fugax, transient ischemic attacks, nonhemispheric symptoms, and strokes. RESULTS: New neurologic symptoms developed in 75 patients (21.8%). Fifty-one (14.8%) had ipsilateral symptoms during follow-up: 18 amaurosis fugax (5.2%), 14 transient ischemic attacks (4%), 5 nonhemispheric symptoms (1.4%), and 14 strokes (4%). Twenty-four patients (6.9%) had contralateral symptoms: 20 strokes (5.8%) and 4 transient ischemic attacks (1.2%). Life-table analysis showed that the annual rate of ipsilateral neurologic events was 8.1%, and the annual rate of stroke was 2.1%. Seventy-five patients (22%) died in the follow-up period. Disease progression to 80% to 99% stenosis or occlusion occurred in 71 of 458 vessels (15.5%). The internal carotid arteries that showed evidence of disease progression had a significantly higher initial peak systolic velocity (251 vs 190 cm/s; P <.0001) and end diastolic velocity (74 vs 52 cm/s; P < 0.0001). Black patients and patients with ischemic heart disease were at a higher risk for disease progression. We could not identify any atherosclerotic risk factors that reliably predicted patients in whom future ipsilateral neurologic symptoms were more likely to develop. However, there was an increased risk of stroke associated with progression of disease. CONCLUSION: Patients who are asymptomatic and who have moderate carotid stenoses are at significant risk for neurologic symptoms and death, but have a relatively low incidence rate of ipsilateral events. The initial flow characteristics in the stenotic vessel are predictive of future disease progression, but they are not helpful in identifying patients in whom symptoms will develop.