Team-based incremental acquisition of large-scale unprecedented systems

This paper addresses certain shortcomings of traditional acquisition approaches, especially for large-scale, unprecedented systems. Shortcomings in the requirements engineering processes are emphasized. We review incremental acquisition approaches and identify issues essential to successful application of incremental acquisition approaches to overcome these shortcomings.In identifying these issues, cases based on systems being developed by the Air Force Space Command are examined. They are the Granite Sentry (GS), Space Defense Operations Centers (SPADOC), and Mobile Command and Control System (MCCS) programs. Three key aspects of the lessons learned from these efforts parallel the steps suggested by a recent Air Force Studies Board report for reducing risk in developing unprecedented systems. These are team-based development, managing requirements uncertainty and change, and increased use of incremental acquisition approaches.This work was sponsored by the U.S. Department of Defense. Approved for public release, distribution unlimited. The views expressed in this article are those of the authors and do not reflect the official policy or position of the U.S. Air Force, the Department of Defense or the U.S. Government.     

Virtopsy,a new imaging horizon in forensic pathology: virtual autopsy by postmortem multislice computed tomography (MSCT) and magnetic resonance imaging (MRI)--a feasibility study

Using postmortem multislice computed tomography (MSCT) and magnetic resonance imaging (MRI), 40 forensic cases were examined and findings were verified by subsequent autopsy. Results were classified as follows: (I) cause of death, (II) relevant traumatological and pathological findings, (III) vital reactions, (IV) reconstruction of injuries, (V) visualization. In these 40 forensic cases, 47 partly combined causes of death were diagnosed at autopsy, 26 (55%) causes of death were found independently using only radiological image data. Radiology was superior to autopsy in revealing certain cases of cranial, skeletal, or tissue trauma. Some forensic vital reactions were diagnosed equally well or better using MSCT/MRI. Radiological imaging techniques are particularly beneficial for reconstruction and visualization of forensic cases, including the opportunity to use the data for expert witness reports, teaching, quality control, and telemedical consultation. These preliminary results, based on the concept of "virtopsy," are promising enough to introduce and evaluate these radiological techniques in forensic medicine.     

Anise oil as para-methoxyamphetamine (PMA) precursor

These days, MDMA is one of the most popular drugs of abuse. Due to its illegality, MDMA and its chemical precursors are watched by governmental organizations in many countries. To avoid conflicts with legal instances, underground chemists have tried to market several new unregulated amphetamine analogues, such as 4-MTA. Para-methoxyamphetamine (PMA), on the other hand, is regulated by law but its precursors are easily obtained since they are cheap and unwatched. This article presents such a case, namely the large scale synthesis of PMA using anethole, a main constituent of anise oil, as precursor. Anethole has been converted to its phenyl acetone analogue via peracid oxidation, while PMA itself has been synthesized using this ketone as precursor in the Leuckart synthesis. The synthesis of PMA using anethole as starting product has been investigated applying GC/MS and GC-HSPME/MS techniques, hereby discovering new specific (4-methoxyphenol) and already identified synthesis impurities (4-methyl-5-(4-methoxyphenyl)pyrimidine, N-(beta-4-methoxyphenylisopropyl)-4-methoxybenzyl methyl ketimine, 1-(4-methoxyphenyl)-N-(2-(4-methoxyphenyl)-1-methylethyl-2-propanamine, 1-(4-methoxyphenyl)-N-methyl-N-(2-(4-methoxyphenyl)-1-methylethyl-2-propanamine, N-(beta-4-methoxyphenylisopropyl)-4-methoxybenzaldimine). The new impurity 4-methoxyphenol is specific for the application of a peracid oxidation method where anethole is used as precursor.     

浅谈农业信息化的开发和利用

中国已经加入世界贸易组织。要减少加入WTO对农业所产生的冲击,必须实现跨越式发展。而以信息化技术为先 导的农业商新技术将为这次跨越武发展提供机遇。因此,要抓住这一有利时机,加快农业信息化步伐,全面推动现代农业信息技 术在整个农业领域的渗透和应用,促进农业实现“两个根本性转交”,促进农业现代化的早日实现。     

尸体玫瑰齿现象与死因的关系

目的研究尸体玫瑰齿现象与死因的关系及其法医学意义。方法采用观察法研究各种死因的大鼠尸体玫瑰齿现象。每种死因观察10只大鼠,其中8只死后即刻取牙齿观察(非腐败组),2只死后置水中腐败出现尸臭时取牙齿观察(腐败组),观察后立即将牙齿置于酒精中浸泡,分别于不同浸泡时间再进行观察。结果各种死因非腐败组即刻取牙观察均未见玫瑰齿现象,但置酒精中浸泡后均逐渐出现玫瑰齿现象,并在浸泡4h后玫瑰齿颜色显著;腐败组取牙齿后即刻观察均见玫瑰齿现象,置酒精浸泡1h后颜色不改变;腐败组较非腐败组颜色明显。结论尸体玫瑰齿现象与死因无关,不能作为法医学鉴定死因的依据。     

Maintenance of the ENFSI proficiency test program on identification of GSR by SEM/EDX (GSR2003)

Within the framework of the ENFSI Expert Working Group "Firearms," every second year, a proficiency test on the detection and identification of GSR by SEM/EDX is carried out. This proficiency test is a development and extension of the previous proficiency test GSR2001. The test material was again designed by the organization panel and manufactured by an external company for SEM accessories. This time the participating laboratories were requested to determine the total number of PbSbBa containing particles on a test sample following their own laboratory specific methods of automated GSR particle search and detection by SEM/EDX. One synthetic particle sample (SPS) with artificial GSR particles was dispatched to all participants. This paper summarizes the results of the study and assesses the overall performance of the participating laboratories. Furthermore an extended statistical evaluation and a comparison with previous studies was carried out.     

The potential of venous air embolism ascending retrograde to the brain

A bench study was performed to investigate the potential of air bubbles entering a central vein via a central venous catheter to ascend retrograde to the brain. The results support the hypothesis that air bubbles may rise retrograde against the venous blood flow, depending on bubble size, central vein diameter and cardiac output. A review of radiological findings in published case reports indicates that the occurrence of retrograde cerebral air embolism is underestimated.