Hair analysis for cocaine: Factors in laboratory contamination studies and their relevance to proficiency sample preparation and hair testing practices

Hair samples were contaminated by rubbing with cocaine (COC) followed by sweat application, multiple shampoo treatments and storage. The samples were then washed with isopropanol for 15 min, followed by sequential aqueous washes totaling 3.5 h. The amount of drug in the last wash was used to calculate a wash criterion to determine whether samples were positive due to use or contamination. Analyses of cocaine and metabolites were done by LC/MS/MS. These procedures were applied to samples produced by a U.S. government-sponsored cooperative study, in which this laboratory participated, and to samples in a parallel in-house study. All contaminated samples in both studies were correctly identified as contaminated by cutoff, benzoylecgonine (BE) presence, BE ratio, and/or the wash criterion. A method for determining hair porosity was applied to samples in both studies, and porosity characteristics of hair are discussed as they relate to experimental and real-world contamination of hair, preparation of proficiency survey samples, and analysis of unknown hair samples.     

Understanding management: Henry Mintzberg on the activities of managers

The Nature of Managerial Work, 2^nd edition. By Henry Mintzberg . Engle‐wood Cliffs, N.J.: Prentice‐Hall.     

论海上火灾免责

海上火灾免责 ,从其定义、起因 ,到举证顺序 ,举证对象 ,也即火灾起因的举证责任和承运人过失的举证责任等至关重要的问题 ,我国立法上存在较明显的缺陷 ,一是未分清火灾举证责任的举证顺序。二是未区分火灾起因的举证责任与承运人过失的举证责任。三则有关举证责任的规定 ,含义模糊易引起歧义 ,实际上已经造成某些权威人士的错误解释。四则在保留“承运人本人”狭窄的范围的同时 ,却引进《汉堡规则》中的明示举证责任 ,而且有过之无不及。     

Explaining Responsiveness in Collaboration: Administrator and Citizen Role Perceptions

Between 2003 and 2006, researchers facilitated a collaborative learning process with representatives of Los Angeles neighborhood councils and officials from city agencies. In two cases, each involving a large city agency, the quality of responsiveness on the part of agency officials to participating citizens was substantially different. This study considers the reasons why agency officials differed in their responsiveness. Using an inductive qualitative and quantitative content analysis across three sources of data, the study develops theory pertaining to bureaucratic responsiveness to citizens in collaborative processes. Specifically, the case findings are generalized to theory through seven propositions for future study. The study's key finding is that administrator and citizen perceptions of their own and the other party's roles may influence the quality of responsive behavior in collaborative activity. The propositions identify subfactors or contingencies that may allow administrators to be more responsive to citizens in collaborative processes.