For large cohort studies with rare outcomes, the nested case-control design only requires data collection of small subsets of the individuals at risk. These are typically randomly sampled at the observed event times and a weighted, stratified analysis takes over the role of the full cohort analysis. Motivated by observational studies on the impact of hospital-acquired infection on hospital stay outcome, we are interested in situations, where not necessarily the outcome is rare, but time-dependent exposure such as the occurrence of an adverse event or disease progression is. Using the counting process formulation of general nested case-control designs, we propose three sampling schemes where not all commonly observed outcomes need to be included in the analysis. Rather, inclusion probabilities may be time-dependent and may even depend on the past sampling and exposure history. A bootstrap analysis of a full cohort data set from hospital epidemiology allows us to investigate the practical utility of the proposed sampling schemes in comparison to a full cohort analysis and a too simple application of the nested case-control design, if the outcome is not rare.
City managers and urban sociologists traditionally viewed ethnic places as undesirable areas of overcrowding and social pathology. Regarded as either transitional districts or obstacles to modernization, ethnic places were subject to slum clearance during the modernist phase of urban development. Ethnic places have acquired a new historical and sentimental salience in the "postmodern" developmental era. Preservationist activists and minority "place entrepreneurs" project ethnic culture and symbolic representations in defensive or proactive ways to stimulate neighborhood revitalization. These trends are evident in the recent urban developmental history of Houston, Texas. 相似文献
We re-evaluate Andreu and Spanos's findings in favour of trend stationarity by considering the extended Nelson-Plosser data set. This expanded (to 1988) data set includes a period of rather different behaviour compared with the original Nelson-Plosser data used by Andreou and Spanos. We find that Andreou and Spanos's models (with only minor adjustments) exhibit remarable stability over this extended period, and indicate that their conclusions are more robust than they have shown. 相似文献
A mechanistic model is presented describing the clearance of a compound in a precision-cut liver slice that is incubated in a culture medium. The problem of estimating metabolic rate constants in PBPK models from liver slice experiments is discussed using identifiability analysis. From the identifiability problem analysis, it appears that in addition to the clearance, the compound's free fraction in the slice and the diffusion rate of the exchange of the compound between culture medium and liver slice should be identified. In addition, knowledge of the culture medium volume, the slice volume, the compound's free fraction, and octanol-water-based partition between medium and slice is presupposed. The formal solution for identification is discussed from the perspective of experimental practice. A formally necessary condition for identification is the sampling of parent compound in liver slice or culture medium. However, due to experimental limitations and errors, sampling the parent compound in the slice together with additional sampling of metabolite pooled from the medium and the slice is required for identification in practice. Moreover, it appears that identification results are unreliable when the value of the intrinsic clearance exceeds the value of the diffusion coefficient, a condition to be verified a posteriori. 相似文献
The development of a Municipal Information System, or currently better known as a local spatial data infrastructure, is considered complex due to the required inter-institutional relationships. In many developing countries Geographical Information Systems (GISs) are introduced but the benefits are modest as no changes take place in technical and organisational structure of organisations. Digital databases and computer-aided design (CAD) maps are mushrooming in great variety within different private and public institutions, municipal organisations and even within single departments and with structures similar to the paper period and thus operating on a stand-alone basis.Many national mapping agencies are not able to provide large-scale digital urban base maps, while the absence or low quality of cadastres makes those basic core data sets unavailable or inaccessible. The result is that duplication and incompatible data are frequently observed and also donor-driven stand-alone projects have a limited impact through the lack of institutional embedding and are not able to mature from the project to the institutional level. However, a positive sign is that there is an increasing awareness among data producers and consumers that investments in the development of digital data sets should be combined to reduce costs and increase benefits from especially GIS, and information and communication technology (ICT) in general.Within Trujillo a long-term vision was developed to make full use of ICT and GIS to modernise all operations of the Municipality to increase the efficiency and effectiveness of its tasks. However, large investments are not feasible due to the very limited municipal budgets. To guarantee the support of the municipal council, short-term results are required. This paper describes three ‘products’ as part of the vision to develop through a step-by-step approach a local spatial data infrastructure for Trujillo.The three, rather different, products are:
1. fiscal cadastre, to increase municipal revenues through property taxation;
2. an ‘environmental atlas’ based on a compatible spatial and attribute data sets from a variety of organisations; and
3. a municipal website with interactive GIS and meta data information.
The paper concludes with some comments on the institutional and political requirements for the successful development of a local spatial data infrastructure and stresses that such an infrastructure is not a product but an incremental development process that will progress only in case such a process is simple, cost effective, user-friendly, and flexible with clear products.Political interest and institutional stability and genuine interest for inter-institutional cooperation will add much to the success of this process. 相似文献
Zusammenfassung Der Beitrag beschreibt Planung, Verlauf und abschlie?ende Beurteilung eines gruppendynamischen Seminars, in dem für angehende
Supervisorinnen und Supervisoren das Thema Organisations-Entwicklung dargestellt und vermittelt werden sollte. Ausgangspunkt
war die Kl?rung des Inhaltsraums von Organisations-Entwicklung als geplantem sozialen Wandel, der auf sozialwissenschaftlicher
Grundlage zielgerichtet, strategisch und mit Zeitperspektive in der Zusammenarbeit zwischen externer und interner Sach-, Prozess-
und Entscheidungskompetenz durchgeführt wird. Als Ziele des Seminars wurden festgelegt, Organisations-Entwicklung als sozialwissenschaftliches
Instrument zu begründen, Organisations-Entwicklung-Schritte zu konzipieren und sie kollegial zu kommunizieren. Darüber hinaus
wurden Qualit?tskriterien für das Seminar formuliert: Praxisn?he, Kl?rung des Inhaltsraum Selbstorganisation, Selbststeuerung,
Ressourcenaktivierung, Konfliktregulierung, Analyse des Gruppenprozesses, Nutzung von Feldkompetenz und Verhaltensmodellen,
Etablierung von Feedbackschleifen, Koordination und Synergie, kollegialer Austausch und Kl?rung pers?nlicher Organisations-Entwicklungs-Fragen.
Bausteine und Lernorte des Seminars waren das Plenum, die Lernpartnerschaft, das OE-Team, die Beobachterfunktion, die Tagesreflexion,
die Sitzung Frage und Antwort, die Darstellung von Praxisf?llen, das Plenum-Feinsteuerung, die Analyse der Arbeitsprozesse
des OE-Teams sowie Transfer und Auswertung. Der tats?chliche Verlauf des Seminars wird aus der Perspektive des Leiters kommentiert.
Anhand von Verlaufsbeobachtungen und Teilnehmer?u?erungen wird der Eindruck begründet, dass diese Form des Vorgehens als lernintensiv,
autonomief?rdernd und für die zu erwerbende Supervisionskompetenz als praxisrelevant betrachtet werden kann.
This article describes the plantification, progress and final evaluation of a group-dynamic seminar for future supervisors
in which the topic organization development was presented and introduced. The content of organization development was first
defined as a planned social change which is executed based on social sciences in a goal-oriented, strategic way which considers
the time perspective of the cooperation between external and internal specialised-, process- and decision competence. Goals
of the seminar were to justify that organisation development is a social science tool, to plan organization development steps
and to communicate them to peer seminar participants. Further more, the following quality criteria for the seminar were formulated:
practice orientation, definition of self-organisation content, self regulation, resources activation, conflict regulation,
group process analysis, field competence and behaviour models usage, feedback establishment, coordination and synergy, mutual
peer exchange and finding answers to personal questions about organization development. The building blocks and learn places
of the seminar were the plenary sessions, the learning partnership, the od-teams, the observer function, the day analysis,
the questions and answers session, the case study presentation, the analysis of the work processes as well as transfer and
evaluation. The progression of the seminar is commented from the point of view of the seminar leader. Progress observations
and participant’s feedback justify the impression that this way to conceptualise provides an intensive learning experience,
supports autonomy and provides relevant and practical supervision competence.
J?rg Fengler ist Professor der Psychologie an der Universit?t zu K?ln, Heilp?dagogische Fakult?t. Arbeitsschwerpunkte sind
u.a. P?dagogische und Klinische Psychologie. Er ist Herausgeber dieser Zeitschrift. 相似文献