Focused on the field of knowledge lying between digital and analog circuit theory, this new text will help engineers working with digital systems shorten their product development cycles and help fix their latest design problems. The scope of the material covered includes signal reflection, crosstalk, and noise problems which occur in high speed digital machines (above 10 megahertz). This volume will be of practical use to digital logic designers, staff and senior communications scientists, and all those interested in digital design.

Preface to the Seventh Edition Since the first edition of this work in 1986, enormous changes have occurred in professional ethics in Arkansas: the ...

Questions are raised about the potential of embryo cloning, or blastomere separation, both to increase the rate of pregnancy following in vitro fertilization and to provide sufficient material for preimplantation genetic diagnosis. Nevertheless, it is concluded that research on blastomere separation in the human should continue.

SummaryThe Gainj of highland Papua New Guinea do not use contraception but have a total fertility rate of only 4·3 live births per woman, one of the lowest ever recorded in a natural fertility setting. From an analysis of cross-sectional demographic and endocrinological data, the causes of low reproductive output have been identified in women of this population as: late menarche and marriage, a long interval between marriage and first birth, a high probability of widowhood at later reproductive ages, low (...) effective fecundability and prolonged lactational amenorrhoea. These are combined with near-universal marriage, a low prevalence of primary sterility and a pattern of onset of secondary sterility similar to that found in other populations. Of all the factors limiting fertility, by far the most important are those involved in birth spacing, especially lactational amenorrhoea. (shrink)

This study examines firms that have experienced an industrial and/or environ-mental crisis and proposes that top management team (TMT) characteristics will affect a firm's ability to minimize the severity of these crisis events. Specifically, heterogeneity in the TMT will exhibit a curvilinear (U-shaped) relationship with the severity of firm crises. Our results suggest that a moderate level of age and tenure heterogeneity are positively related to a firm's ability to successfully minimize the severity of crises. Variance in educational backgrounds was (...) unrelated to crisis severity. Functional background heterogeneity exhibited a curvilinear relationship with crisis severity but was not U-shaped as hypothesized. (shrink)

Background While prenatal surgery historically was performed exclusively for lethal conditions, today intrauterine surgery is also performed to decrease postnatal disabilities for non-lethal conditions. We sought to describe physicians' attitudes about prenatal surgery for lethal and non-lethal conditions and to elucidate characteristics associated with these attitudes. Methods Survey of 1200 paediatric surgeons, neonatologists and maternal–fetal medicine specialists. Results Of 1176 eligible physicians, 670 responded. In the setting of a lethal condition for which prenatal surgery would likely result in the child (...) surviving with a severe disability, most respondents either disagreed or strongly disagreed that they would recommend the surgery. Male physicians were twice as likely to recommend surgery for the lethal condition, as were physicians who believe that abortion is morally wrong. Older physicians were less likely to recommend surgery. For non-lethal conditions, most respondents agreed that they would recommend prenatal surgery, even if the surgery increases the risk of prematurity or fetal death. Compared with MFMs, surgeons were less likely to recommend such surgery, as were physicians not affiliated with a fetal centre, and physicians who were religious. Conclusion Physician’s attitudes about prenatal surgery relate to physicians’ beliefs about disability as well as demographic, cultural and religious characteristics. Given the variety of views, parents are likely to receive different recommendations from their doctors about the preferable treatment choice. (shrink)

The authors present an approach to conceptualising and predicting environmental conflicts in which conflicts are analysed as a continuum of disagreement over values and options. They also operationalise this approach using an online values-centred survey tool, the ‘public-to-public decision support system’ (P2P-DSS). The authors put values and conflict in environmental management into perspective. Next, they review how values are defined in scholarship and operationalised for decision support. The relevance of values research to con-flict management is presented. With reference to a (...) real-world aggregate-mining conflict, the authors demonstrate how P2P-DSS can be used to collect data and categorise conflicts to enhance environmental management decision-making. The authors argue that P2P-DSS has potential to support values-sensitive thinking for environmental conflict management. They then set out research priorities to investigate the theoretical and practical implications of this approach. This work contributes to advancing values research in environmental conflict management and expanding values-based decision-making. (shrink)

School violence is a burning issue these days. This book provides an in-depth analysis of violence prevention programs and an assessment of their effectiveness, using data from observations, individual interviews, and focus groups, as well as published data from the schools. It is distinguished by its focus on the cultural and structural context of school violence and violence prevention efforts. Where most other researchers use quantitative measures, such as surveys, to assess the effectiveness of violence prevention programs, the authors of (...) this book use qualitative research and ethnography to study the environment where such programs take place. Thus, this work--one of only a few ethnographic studies of violence prevention programs in schools--links previous quantitative research on the topic and critical ethnography. _Preventing Violence in Schools: A Challenge to American Democracy_: *includes voices of school students, accused of practicing violence, who have been participants in violence prevention programs; *analyzes a citywide peer mediation program ; *examines the kinds of violence recognized in schools and the ways schools themselves may perpetuate violence; and *describes a violence prevention program for students at an alternative school. _Preventing Violence in Schools: A Challenge to American Democracy_ is highly relevant for students in courses on urban education, foundations of education, education and social policy, youth and the law, and qualitative research, and for teachers, administrators, and other professionals, such as school psychologists and guidance counselors, at the middle and high school levels. (shrink)

Adults and infants display a robust ability to perceive the unity of a center-occluded object when the visible ends of the object undergo common motion (e.g. Kellman, P.J., Spelke, E.S., 1983. Perception of partly occluded objects in infancy. Cognitive Psychology 15, 483±524). Ecologically oriented accounts of this ability focus on the primacy of motion in the perception of segregated objects, but Gestalt theory suggests a broader possibility: observers may perceive object unity by detecting patterns of synchronous change, of which common (...) motion is a special case. We investigated this possibility with observations of adults and 4-month-old infants. Participants viewed a center-occluded object whose visible surfaces were either misaligned or aligned, stationary or moving, and unchanging or synchronously changing in color or bright- ness in various temporal patterns (e.g. ¯ashing). Both alignment and common motion con- tributed to adults' perception of object unity, but synchronous color changes did not. For infants, motion was an important determinant of object unity, but other synchronous changes and edge alignment were not. When a stationary object with aligned edges underwent syn- chronous changes in color or brightness, infants showed high levels of attention to the object, but their perception of its unity appeared to be indeterminate. An inherent preference for fast over slow ¯ash rates, and a novelty preference elicited by a change in rate, both indicated that infants detected the synchronous changes, although they failed to use them as information for object unity. These ®ndings favor ecologically oriented accounts of object perception in which surface motion plays a privileged role. Ó 1999 Elsevier Science B.V. All rights reserved. (shrink)