A comparison of the economic and environmental performances of conventional and organic farming: evidence from financial statements

While conventional farming systems face serious problems of sustainability, organic agriculture is seen as a more environmentally friendly system since it favours renewable resources, recycles nutrients, uses the environment’s own systems for controlling pests and diseases, sustains ecosystems, protects soils, and reduces pollution. At the same time organic farming promotes animal welfare, the use of natural foodstuffs, product diversity and the avoidance of waste, among other practices. However, the future of organic agriculture will depend on its economic viability and on the determination shown by governments to protect these practices. This paper performs panel regressions with a sample of Catalan farms (Spain) to test the influence of organic farming on farm output, costs and incomes. It analyses the cost structures of both types of farming and comments on their social and environmental performance.organic farming, conventional farming, social/environmental/financial performance, social and environmental accounting, Agribusiness, Environmental Economics and Policy, Farm Management, Q01, Q12, Q51, M41,

Successful use of recombinant tissue plasminogen activator in a patient with relapsing peritonitis

Intraperitoneal (IP) administration of either streptokinase (SK) or urokinase (UK) has assumed an adjunctive role to antibiotic therapy in selected patients with relapsing peritonitis. In these circumstances, bacteria may be protected from antibiotics through sequestration in either fibrinous structures or biofilms within the lumen of the peritoneal dialysis (PD) catheter or the peritoneal cavity. In some cases, it appears that disruption of these sheltered microenvironments by thrombolytic agents facilitated eradication of the offending organism and obviated the need for catheter removal, replacement, or interim hemodialysis. Although IP SK has been generally well tolerated as additive therapy in relapsing peritonitis, sporadic reports of significant complications, such as abdominal pain, fever, and severe hypotension, have precluded its more widespread acceptance. The only other thrombolytic agent used in this setting, UK, is presently unavailable because of a manufacturing shortfall. Therefore, adjunctive thrombolytic therapy for relapsing peritonitis is currently restricted. To circumvent these limitations, we devised an IP tissue plasminogen activator (tPA) protocol to eliminate recurring infection in a patient undergoing chronic ambulatory PD. After a third episode of peritonitis caused by Enterobacter cloacae, treated twice previously with an adequate antibiotic regimen, we instilled 6 mL of tPA (1 mg/mL) into the PD catheter for a 2-hour dwell time. The treatment was well tolerated and, in conjunction with a third course of antibiotic therapy, has produced an infection-free interval of 8 months. © 2001 by the National Kidney Foundation, Inc

Digital Learners in Scientific Literature: Design and Implementation of a Systematic Review from 2001 to 2010

En la última década han surgido numerosas denominaciones que tratan de definir a una nueva generación de estudiantes. Una generación digital que ha crecido rodeada de tecnología y que, supuestamente, poseen unas características comunes y diferenciadas de las anteriores. El objetivo de este artículo es analizar la evolución y la relación de estas denominaciones en la literatura científica. Para ello, se muestra el proceso de construcción de una herramienta y el diseño de una estrategia para la revisión sistemática de esta temática en los artículos publicados en ISI Web of Science entre 2001 y 2010, así como los principales resultados.In the last decade have emerged numerous denominations that seek to define a new generation of students. A digital generation that has grown up surrounded by technology and supposedly therefore has common and distinct characteristics. The aim of this paper is to investigate the evolution and the relationship of these denominations in the scientific literature. For this purpose, a tool and a strategy is built and designed for the systematic review of this subject in articles published in ISI Web of Science from 2001 to 2010, and the main results are shown.Ministerio de Educación (España) PR20100394Ministerio de Ciencia e Innovación (España) EDU2008-0147

Celebrity games

We introduce Celebrity games, a new model of network creation games. In this model players have weights (W being the sum of all the player's weights) and there is a critical distance ß as well as a link cost a. The cost incurred by a player depends on the cost of establishing links to other players and on the sum of the weights of those players that remain farther than the critical distance. Intuitively, the aim of any player is to be relatively close (at a distance less than ß ) from the rest of players, mainly of those having high weights. The main features of celebrity games are that: computing the best response of a player is NP-hard if ß>1 and polynomial time solvable otherwise; they always have a pure Nash equilibrium; the family of celebrity games having a connected Nash equilibrium is characterized (the so called star celebrity games) and bounds on the diameter of the resulting equilibrium graphs are given; a special case of star celebrity games shares its set of Nash equilibrium profiles with the MaxBD games with uniform bounded distance ß introduced in Bilò et al. [6]. Moreover, we analyze the Price of Anarchy (PoA) and of Stability (PoS) of celebrity games and give several bounds. These are that: for non-star celebrity games PoA=PoS=max{1,W/a}; for star celebrity games PoS=1 and PoA=O(min{n/ß,Wa}) but if the Nash Equilibrium is a tree then the PoA is O(1); finally, when ß=1 the PoA is at most 2. The upper bounds on the PoA are complemented with some lower bounds for ß=2.Peer ReviewedPostprint (author's final draft

Diphoton decay of the higgs from the Epstein--Glaser viewpoint

We revisit a nearly ten-year old controversy on the diphoton decay of the Higgs particle. To a large extent, the controversy turned around the respective merits of the regularization techniques employed. The novel aspect of our approach is that no regularization techniques are brought to bear: we work within the Bogoliubov--Epstein--Glaser scheme of renormalization by extension of distributions. Solving the problem actually required an expansion of this method's toolkit, furnished in the paper.Comment: 45 pages, to appear in Eur. Phys. J.

The diffusion of patented oil and gas technology with environmental uses: a forward patent citation analysis [WP IEB]

Relevant advances in the mitigation of environmental impact could be obtained by the appropriate diffusion of existing environmental technologies. In this paper, we look at the diffusion of knowledge related to environmental technologies developed within the oil and gas industry. To assess knowledge spillovers from oil and gas inventions as a measure of technology diffusion, we rely on forward patent citations methodology. Results show that there is a strong likelihood that the citing patent will be eventually linked to environmental technologies if the original oil and gas invention has already environmental uses. Moreover, both intra and intersectoral spillovers produce a "turnabout" effect, meaning that citing patents show the opposite quality level of the cited patent. Our results support the idea that more sector-specific environmental policies, with an emphasis on diffusion, would significantly improve the use of environmental technologies developed within the oil and gas industry

The diffusion of patented oil and gas technology with environmental uses: a forward patent citation analysis

Relevant advances in the mitigation of environmental impact could be obtained by the appropriate diffusion of existing environmental technologies. In this paper, we look at the diffusion of knowledge related to environmental technologies developed within the oil and gas industry. To assess knowledge spillovers from oil and gas inventions as a measure of technology diffusion, we rely on forward patent citations methodology. Results show that there is a strong likelihood that the citing patent will be eventually linked to environmental technologies if the original oil and gas invention has already environmental uses. Moreover, both intra and intersectoral spillovers produce a 'turnabout' effect, meaning that citing patents show the opposite quality level of the cited patent. Our results support the idea that more sector-specific environmental policies, with an emphasis on diffusion, would significantly improve the use of environmental technologies developed within the oil and gas industry. Keywords: Forward patent citations; petroleum industry; technology flows; environmental and technology policies