The effects of cyclophosphamide and nor-nitrogen mustard administration to one-day-old mice

Zusammenfassung Störung der normalen Entwicklung und des Wachstums ein Tag alter Mäuse wurde durch Injektion von Cyclophosphamid verursacht. Verabreichung von Nor-Chlormethin zeigte keine derartigen Effekte und es wird vermutet, dass diese Unterschiede durch die pharmakokinetischen Eigenschaften dieser Stoffe verursacht sein könnten.

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This work was supported by GRS Grant No. 71-0955 awarded by The College of Human Medicine, Michigan State University.     

Breast feeding, birth spacing and their effects on child survival

It has long been known that breast feeding inhibits female fertility and that it is a factor in restricting population growth. But just how important is it?     

The use of the information-theoretic entropy in thermodynamics

When considering controversial thermodynamic scenarios such as Maxwell's demon, it is often necessary to consider probabilistic mixtures of macrostates. This raises the question of how, if at all, to assign entropy to them. The information-theoretic entropy is often used in such cases; however, no general proof of the soundness of doing so has been given, and indeed some arguments against doing so have been presented. We offer a general proof of the applicability of the information-theoretic entropy to probabilistic mixtures of macrostates that is based upon a probabilistic generalisation of the Kelvin statement of the second law. We defend the latter and make clear the other assumptions on which our main result depends. We also briefly discuss the interpretation of our result.     

Transiting circumbinary planets Kepler-34 b and Kepler-35 b

Most Sun-like stars in the Galaxy reside in gravitationally bound pairs of stars (binaries). Although long anticipated, the existence of a 'circumbinary planet' orbiting such a pair of normal stars was not definitively established until the discovery of the planet transiting (that is, passing in front of) Kepler-16. Questions remained, however, about the prevalence of circumbinary planets and their range of orbital and physical properties. Here we report two additional transiting circumbinary planets: Kepler-34 (AB)b and Kepler-35 (AB)b, referred to here as Kepler-34 b and Kepler-35 b, respectively. Each is a low-density gas-giant planet on an orbit closely aligned with that of its parent stars. Kepler-34 b orbits two Sun-like stars every 289?days, whereas Kepler-35 b orbits a pair of smaller stars (89% and 81% of the Sun's mass) every 131?days. The planets experience large multi-periodic variations in incident stellar radiation arising from the orbital motion of the stars. The observed rate of circumbinary planets in our sample implies that more than ～1% of close binary stars have giant planets in nearly coplanar orbits, yielding a Galactic population of at least several million.     

Rapid Institutional Appraisal

A week-long intensive process of staff development and induction called Rapid Institutional Appraisal (RIA) was conducted in November 2000 in the Systems Discipline, Centre for Complexity and Change (CCC), at the Open University. We report the systemic roots and characteristics of the RIA as designed from traditions of soft systems methodology and rapid rural appraisal. Our experiences arising from our own use of RIA are described and the wider implications for organizational learning in a complex organization discussed. While acknowledging limitations with this RIA event, we argue that RIA offers a potential model for staff development for adaptive use in different contexts and on varying scales. The process builds on principles of "conversation" and "multiple perspectives" as the touchstone for establishing a purposeful community of practice.