A Substance Flow Model for Global Phosphorus

A mechanistic model of phosphorus flows through the global food system was developed to address questions about the relative effectiveness of and interactions among potential conservation interventions. Phosphorus is required as a fertilizer for producing food, and there is no substitute. Most phosphorus used in agriculture is mined, and 75% of the world’s reserves are controlled by a single country: Morocco. Thus the world’s food supply is potentially vulnerable to geopolitical conditions. Although known reserves can satisfy current demand for several centuries, it is nevertheless the case that an essential resource is being used unsustainably. Only about 10% of the phosphorus used in agriculture reaches our plates. Losses along the way contribute to water pollution, causing eutrophication. In freshwater bodies this produces toxic drinking water and fish kills. In the coastal marine environment eutrophication causes hypoxic (low oxygen) zones, popularly called “dead zones, in many parts of the world. Thus conservation of phosphorus is of interest both to preserve the resource and to prevent pollution. The conservation interventions considered include: population control; reduction in meat fraction in the diet (MFD); animal manure use efficiency (MUE); agricultural phosphorus use efficiency (PUE); the fraction of food supply that is wasted; the fraction of food waste that is recycled; the fraction of human waste that is recycled. The model shows that the meat fraction in the diet is the most sensitive of these factors, and this factor interacts with PUE and MUE. Furthermore, there is a minimum MFD below which it actually becomes necessary to mine more phosphorus. Another conclusion is that recycling is much less effective than reduction in conserving the resource

Examples of heterogeneous catalytic processes for fine chemistry

Fine chemicals are highly pure substances that are commercially produced by chemical reactions for highly specialized applications. In most cases, however, these reactions involve stoichiometric and highly polluting steps. A possible solution is the development of processes using enzymatic, homogeneous or heterogeneous catalysts. In this review, selected examples of clean heterogeneously-catalyzed reactions applied to the synthesis of fine chemicals are reported for the purpose of highlighting the growing need for more sustainable industrial processes, i.e., processes that produce minimal waste and avoid as much as possible the use of toxic and/or hazardous reagents and solvents. A thorough knowledge of catalyst properties, reaction conditions and interactions with the reacting substrate are essential for optimizing the synthesis, thus making it possible to move on from laboratory to industrial production

Using normative ethics for building a good evaluation of research practices: towards the assessment of researcher’s virtues

In this paper, we propose the adoption of moral philosophy and in particular normative ethics, to clarify the concept of “good” evaluation of “research practices”. Using MacIntyre (1985)’s notion of a practice we argue that research is a form of social practice. As a result of this characterization, we claim that research practice typically requires three typologies of researcher: the leader, the good researcher and the honest researcher. Reflecting on what is a “good” research practice and on what is the role of researchers in it provides insight into some aspects of both the self-assessment process and how this promotes individual improvement. Moreover, this kind of reflection helps us to describe the functions (missions) of the research practices. A “good” evaluation should take into account all the building constituents of a “good” research practice and should be able to discriminate between good and bad research practices, while enforcing the functions of good research practices. We believe that these reflections may be the starting point for a paradigm shift in the evaluation of research practices which replaces an evaluation centred on products with an evaluation focused on the functions of these practices. In the last sections of the paper, we introduce and discuss an important aspect for the implementation of the proposed framework. This relates to the assessment of the virtues of researchers involved in a good research practice. Some examples of questions and preliminary items to include in a questionnaire for the assessment of Virtues in Research Practices are also provided

The Lockman Hole Project: new constraints on the sub-mJy source counts from a wide-area 1.4 GHz mosaic

This paper is part of a series discussing the results obtained in the framework of a wide international collaboration - the Lockman Hole Project - aimed at improving the extensive multiband coverage available in the Lockman Hole region, through novel deep, wide-area, multifrequency (60, 150, 350 MHz, and 1.4 GHz) radio surveys. This multifrequency, multi-band information will be exploited to get a comprehensive view of star formation and active galactic nucleus activities in the high-redshift Universe from a radio perspective. In this paper, we present novel 1.4 GHz mosaic observations obtained with the Westerbork Synthesis Radio Telescope. With an area coverage of 6.6 deg2, this is the largest survey reaching an rms noise of 11 uJy/beam. In this paper, we present the source catalogue (~6000 sources with flux densities S>55 uJy (5sigma), and we discuss the 1.4 GHz source counts derived from it. Our source counts provide very robust statistics in the flux range 0.1<S<1 mJy, and are in excellent agreement with other robust determinations obtained at lower and higher flux densities. A clear excess is found with respect to the counts predicted by the semi-empirical radio sky simulations developed in the framework of the Square Kilometre Array Simulated Skies project. A preliminary analysis of the identified (and classified) sources suggests this excess is to be ascribed to star-forming galaxies, which seem to show a steeper evolution than predicted.Comment: accepted for publication on MNRAS. New version that corrects latex errors and contain the correct version of figure 1