ISSUES, ALTERNATIVES AND CONSEQUENCES

Agricultural and Food Policy,

MODELS OF POLICY MAKING

Agricultural and Food Policy,

WETLANDS AND ENDANGERED SPECIES: EDUCATIONAL ASSISTANCE NEEDS OF EXTENSION EDUCATORS

Environmental Economics and Policy,

Mass-Radius Relations and Core-Envelope Decompositions of Super-Earths and Sub-Neptunes

Many exoplanets have been discovered with radii of 1-4 Earth radii, between that of Earth and Neptune. A number of these are known to have densities consistent with solid compositions, while others are "sub-Neptunes" likely to have significant hydrogen-helium envelopes. Future surveys will no doubt significantly expand these populations. In order to understand how the measured masses and radii of such planets can inform their structures and compositions, we construct models both for solid layered planets and for planets with solid cores and gaseous envelopes, exploring a range of core masses, hydrogen-helium envelope masses, and associated envelope entropies. For planets in the super-Earth/sub-Neptune regime for which both radius and mass are measured, we estimate how each is partitioned into a solid core and gaseous envelope, associating a specific core mass and envelope mass with a given exoplanet. We perform this decomposition for both "Earth-like" rock-iron cores and pure ice cores, and find that the necessary gaseous envelope masses for this important sub-class of exoplanets must range very widely from zero to many Earth masses, even for a given core mass. This result bears importantly on exoplanet formation and envelope evaporation processes.Comment: 26 pages, 21 figures, 16 tables, accepted to Ap

INCREASING YOUR IMPACT VIA LEADERSHIP DEVELOPMENT

Labor and Human Capital,

"They should have destroyed more": the destruction of public records by the South African state in the final years of apartheid, 1990-1994

Paper presented at the Wits History Workshop: The TRC; Commissioning the Past, 11-14 June, 199

Towards a statement of the S-adic conjecture through examples

The $S$-adic conjecture claims that there exists a condition $C$ such that a sequence has a sub-linear complexity if and only if it is an $S$-adic sequence satisfying Condition $C$ for some finite set $S$ of morphisms. We present an overview of the factor complexity of $S$-adic sequences and we give some examples that either illustrate some interesting properties or that are counter-examples to what could be believed to be "a good Condition $C$".Comment: 2

Ethnographie und ihre Folgen für die Kulturgeographie : eine Kritik des Netzwerkkonzepts in Studien zu translokaler Mobilität

The aim of this article is to show the difference between an interpretative-hermeneutic ethnographic approach deeply embedded in the history of anthropology and ethnographic methods introduced as part of a social science repertoire. Taking the classical "network" as an example, it contrasts the way this concept is generally used in studies on translocal mobility with interpretations of ethnographic research. This not only opens up critical reflections on the role of "networks" when it comes to understanding translocality as a lived experience, but also illustrates what it actually means to follow an interpretative-hermeneutic approach in which ethnographic material is seen to serve as a way to ground, question and refine abstract concepts. The article thus argues that it is through ethnographies and their inherent openness towards the field that a more enriching and creative engagement with theories and methodologies can be achieved than qualitative social science approaches usually allow for