Jen Muller

We dispersed electrochemical etched Si into a colloid of ultrasmall blue luminescent nanoparticles, observable with the naked eye, in room light. We use two-photon near-infrared femtosecond excitation at 780 nm to record the fluctuating time series of the luminescence, and determine the number density, brightness, and size of diffusing fluorescent particles. The luminescence efficiency of particles is high enough such that we are able to detect a single particle, in a focal volume, of 1 pcm3. The measurements yield a particle size of 1 nm, consistent with direct imaging by transmission electron microscopy. They also yield an excitation efficiency under two-photon excitation two to threefold larger than that of fluorescein. Detection of single particles paves the way for their use as labels in biosensing applications. © 2000 American Institute of Physics.

In Alberts zweiten Kommentar zur Nikomachischen Ethik findet sich vor der Kommentierung des Aristoteles-Textes ein eigenständiger Traktat zum allgemeinen Begriff des Guten, der im Rahmen des Artikels erstmals in kritischer Edition zugänglich gemacht wird. In doktrinaler Sicht handelt es sich um einen Text von fundamentaler Bedeutung, insofern Albert verschiedene Definitionen und Bestimmungen des Guten in ihrer inhaltlichen Vereinbarkeit und Konvergenz aufweist. In nuce entwickelt Albert hier die für sein ganzes Werk maßgebliche Metaphysik des Guten, in welche sowohl die Transzendentalienlehre als auch die Grundmotive einer teleologischen Strebensethik aristotelischen Zuschnitts integriert werden. Der ethisch relevante Begriff des Guten findet dadurch seine ontotheologische Fundierung im höchsten Guten, also in Gott. Der vorliegende Artikel rekonstruiert im Anschluss an die kritische Edition die zentralen Argumente des Traktats und verortet diese durch Abgleich mit anderen Schriften in Alberts gesamten Oeuvre und Denken.Albert‘s second commentary on Aristotle‘s Nicomachean Ethics is preceded by an independent treatise dealing with the general concept of the good, which is made accessible in a critical edition in this article for the first time. Regarding its doctrinal contents this treatise proves to be of fundamental importance because Albert demonstrates the compatibility and even the convergence of several different definitions and descriptions of the good, e.g. by Aristotle, Avicenna, Ps.-Dionysius and Boethius. Albert develops in a nutshell his metaphysics of goodness which is of overarching importance for his whole work and which integrates the theory of the transcendentals as well as the basic ideas of an ethical teleology in an Aristotelian vein. Thereby, the concept of the moral good finds its ultimate foundation in the highest good, i.e. in God. Drawing on the text of the presented critical edition the article retraces the central arguments of this treatise and compares them with other writings in order to show their place in Albert’s complete work and thought.

This paper provides new insights into the food security performance of long and short food chains, through an analysis of the resilience of such chains during the severe weather events that occurred in the Australian State of Queensland in early 2011. Widespread flooding cut roads and highways, isolated towns, and resulted in the deaths of people and animals. Farmlands were inundated and there were food shortages in many towns. We found clear evidence that the supermarket-based food chain delivery system experienced significant difficulties in supplying food to flood-affected towns. In contrast, more localized food supply chains—which relied upon supply from growers in peri-urban areas and community-based food initiatives—remained largely intact, and provided food at a time when the supermarkets were limited in their ability to respond to consumer demand. However, on closer examination of food distribution during flooding in the regional city of Rockhampton and in the State capital, Brisbane, the demarcation of success between “long” and “short” food chains became blurred. Both types of food supply chains shared some key resilience characteristics in responding to crisis but diverged in other important ways. We argue that conceptualizing food chains in terms of key elements of resilience—scale, diversity, flexibility and cohesion—may be more fruitful than the short-long dichotomy alone. This approach is particularly useful when prioritizing food security as the basis for evaluating food system sustainability in a context of predicted increases in extreme weather events and future climate change.