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11.
In preparation for an efficacy trial of PRP-T Haemophilus influenzae type b conjugate vaccine, 251 Gambian infants were randomized to receive three doses of PRP-T and diphtheria-tetanus-pertussis (DTP) vaccines at 2, 3 and 4 months of age, either by separate injections, or combined in the same syringe. One month after the third dose, there was no difference between anti-PRP levels in those infants who received the vaccines separately (GMT 5.83 micrograms ml-1), and those who received the vaccines combined (GMT 5.57 micrograms ml-1). The proportions achieving levels of 1.0 microgram ml-1 were 89% and 92% in the "separate" and "combined" vaccine groups, respectively. There were no significant differences between groups in levels of antibody to diphtheria or tetanus. Geometric mean titres of antibody directed against pertussis antigens in the "separate" and "combined" groups were as follows: pertussis toxin 14.2 and 13.1 ELISA units (EU) ml-1; filamentous haemagglutinin 12.2 and 9.7 EU ml-1; pertactin 17.2 and 9.0 EU ml-1 (P < 0.05), fimbrial 2/3 antigens 449 and 364 EU ml-1. The combination of PRP-T and DTP in the syringe prior to administration is safe and immunogenic. The lower levels of anti-pertussis antibody are of unknown clinical significance.  相似文献   
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The relaxation method is used to calculate mole fractions and temperature profiles in a rectification column where a chemical reaction takes place. The method is general and the non-ideal vapor-liquid equilibria can be easily incorporated. The computer time is very low and the danger of divergence can be alleviated by an appropriate guess of relaxation factor. Calculated problems involving esterification reactions are presented.  相似文献   
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This paper describes an empirical study that addresses the issue of communication among members of a software development organization. In particular, data was collected concerning code inspections in one software development project. The question of interest is whether or not organizational structure (the network of relationships between developers) has an effect on the amount of effort expended on communication between developers. The independent variables in this study are various attributes of the organizational structure in which the inspection participants work. The dependent variables are measures of the communication effort expended in various parts of the code inspection process, focusing on the inspection meeting. Both quantitative and qualitative methods were used, including participant observation, structured interviews, generation of hypotheses from field notes, statistical tests of relationships, and interpretation of results with qualitative anecdotes. The study results show that past and present working relationships between inspection participants affect the amount of meeting time spent in different types of discussion, thus affecting the overall inspection meeting length. Reporting relationships and physical proximity also have an effect. The contribution of the study is a set of well-supported hypotheses for further investigation  相似文献   
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Technical debt is a metaphor for delayed software maintenance tasks. Incurring technical debt may bring short-term benefits to a project, but such benefits are often achieved at the cost of extra work in future, analogous to paying interest on the debt. Currently technical debt is managed implicitly, if at all. However, on large systems, it is too easy to lose track of delayed tasks or to misunderstand their impact. Therefore, we have proposed a new approach to managing technical debt, which we believe to be helpful for software managers to make informed decisions. In this study we explored the costs of the new approach by tracking the technical debt management activities in an on-going software project. The results from the study provided insights into the impact of technical debt management on software projects. In particular, we found that there is a significant start-up cost when beginning to track and monitor technical debt, but the cost of ongoing management soon declines to very reasonable levels.  相似文献   
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A simplex algorithm used to solve molecular structure from asymptotic momentum values is reported. The geometry of CO23+ molecular ions in linear and bent configurations is reconstructed. A polyatomic molecular ion with trigonal planar symmetry is used to demonstrate the scalability of the algorithm.  相似文献   
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Qualitative methods in empirical studies of software engineering   总被引:1,自引:0,他引:1  
While empirical studies in software engineering are beginning to gain recognition in the research community, this subarea is also entering a new level of maturity by beginning to address the human aspects of software development. This added focus has added a new layer of complexity to an already challenging area of research. Along with new research questions, new research methods are needed to study nontechnical aspects of software engineering. In many other disciplines, qualitative research methods have been developed and are commonly used to handle the complexity of issues involving human behaviour. The paper presents several qualitative methods for data collection and analysis and describes them in terms of how they might be incorporated into empirical studies of software engineering, in particular how they might be combined with quantitative methods. To illustrate this use of qualitative methods, examples from real software engineering studies are used throughout  相似文献   
18.
Victor R. Basili's contributions to software quality   总被引:1,自引:0,他引:1  
This article deals with Victor R. Basili's contributions to software quality. Basili's contributions cover three broad areas: research in the 1970s and early 1980s on software measurement and the Goal Question Metric (GQM) model, research in the 1980s and 1990s on these measurement ideas' maturation into a software engineering model of empirical studies, including the development of the Quality Improvement Paradigm (QIP) and the influence of the NASA Goddard Space Flight Center Software Engineering Laboratory, and research since 1990 in the Experience Factory as a model for creating learning organizations for continuous software process improvement. Some of Basili's most important contributions are in measuring software development processes and products and gifted the community with an invaluable tool: the GQM approach. The GQM approach is based on the assumption that for an organization to measure its products and processes usefully, it must first specify goals for itself and its projects.  相似文献   
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