Inisisting on a Non-Negative price: Oligopoly, Uncertainty, Welfare, and Multiple Equilibria

I study Cournot competition under incomplete, but symmetric, information about the intercept of the linear demand function, while assuming that market price must be non-negative for all demand realisations. Although the non-negativity assumption is very natural, it has only rarely been made in the earlier literature. Yet it has important economic consequences: (1) expected demand effectively becomes convex, which means that multiple (symmetric, pure strategy) equilibria can exist; and (2) expected total surplus ca be larger when the firms do not know demand than when they do. The arguments of the paper are relevant also for price competition and for uncertainty about, e.g., cost or the number of firms, and these issues are discussed

Identificación de especies de lombrices en Uruguay en base a métodos morfológicos y moleculares

Molecular techniques could aid earthworm species identification, especially when morphological characters are not taxonomically informative, or difficult to discern. No previous study has investigated molecular-based methods for earthworm taxonomy in Uruguay. The present study aimed to make a first approach using DNA barcoding as a tool to smoothen the way towards determining the earthworm richness in Uruguay. This study was based on an earthworm collection, identified both by morphological characters and molecular techniques, from samplings from different agricultural soils in Montevideo and Paysandú, Uruguay. Adult individuals were identified by external morphology following available descriptions of regional earthworms. From each morphological group a representative sample was selected for genomic DNA extraction, mitochondrial COI region amplification and sequencing. Sequences obtained were subject to BLAST searches and compared to sequences available in GenBank. Eight out of 11 sequenced exotic species were fully identified and matched morphological characters and molecular information; two were less consistent, with lower sequence similarity percentage; and one could not be fully identified due to lack of close related sequences in GenBank. While most exotic species had representative sequences annotated in GenBank, this was only the case for one native species, highlighting the need to develop this important area at a regional level. This study could kick-start an innovative research program, since there are limited records of earthworm samplings in Uruguay and no identification of species by DNA sequences from national studiesLas técnicas moleculares podrían ayudar a la identificación de especies de lombrices, especialmente cuando los caracteres morfológicos resultan difíciles de discernir. Basado en una colección de lombrices generadas a partir de muestreos en diferentes suelos agrícolas en Montevideo y Paysandú, Uruguay, este estudio representa un primer acercamiento al uso del barcoding del ADN como una herramienta para la determinación de la diversidad de lombrices en Uruguay. Las especies se identificaron tanto por caracteres morfológicos como por técnicas moleculares. Los individuos adultos se identificaron por morfología externa siguiendo las descripciones disponibles de las lombrices presentes en la región. De cada especie morfológica se obtuvo una muestra representativa para extracción de ADN genómico, con posterior amplificación y secuenciación de la región mitocondrial Citocromo Oxidasa I (COI). Las secuencias obtenidas se sometieron a búsquedas BLAST y fueron comparadas con las secuencias disponibles en GenBank. De 11 especies exóticas secuenciadas, ocho se identificaron completamente, encontrándose coincidencia entre caracteres morfológicos e información molecular; en tanto dos fueron menos consistentes, con un menor porcentaje de similitud; y una no logró ser identificada completamente debido a la falta de secuencias relacionadas cercanas en GenBank. Mientras la mayoría de las especies exóticas tenían secuencias representativas anotadas en GenBank, esto ocurrió sólo con una especie nativa, lo que demuestra la necesidad de desarrollar esta importante área a nivel regional. Los escasos registros de muestreos de lombrices en Uruguay, y la ausencia de estudios nacionales referidos a identificación de especies por secuencias de ADN, hacen de este estudio un puntapié inicial para una línea de investigación innovadora

The Role of Bile in the Regulation of Exocrine Pancreatic Secretion

As early as 1926 Mellanby (1) was able to show that introduction of bile into the duodenum of anesthetized cats produces a copious flow of pancreatic juice. In conscious dogs, Ivy & Lueth (2) reported, bile is only a weak stimulant of pancreatic secretion. Diversion of bile from the duodenum, however, did not influence pancreatic volume secretion stimulated by a meal (3,4). Moreover, Thomas & Crider (5) observed that bile not only failed to stimulate the secretion of pancreatic juice but also abolished the pancreatic response to intraduodenally administered peptone or soap

The conceptualisation of health and disease in veterinary medicine

<p>Abstract</p> <p>Background</p> <p>The concept of health, as well as the concept of disease, is central in veterinary medicine. However, the definitions "health" and "disease" are not generally acknowledged by veterinarians. The aim of this study was to examine how the concepts "health" and "disease" are defined in veterinary textbooks.</p> <p>Methods</p> <p>Veterinary textbooks in several disciplines were investigated, but only textbooks with explicit definitions of the concepts were selected for examination.</p> <p>Results</p> <p>Eighty out of the 500 relevant books within veterinary medicine were written for non-veterinarians. Eight percent of the books had an explicit definition of health and/or disease. More frequently, textbooks written for non veterinarians did have definitions of health or disease, compared to textbooks written for professionals. A division of health definitions in five different categories was suggested, namely:</p> <p>1. Health as normality, 2. Health as biological function, 3. Health as homeostasis, 4. Health as physical and psychological well-being and 5. Health as productivity including reproduction.</p> <p>Conclusion</p> <p>Few veterinary textbooks had any health or disease definition at all. Furthermore, explicit definitions of health stated by the authors seemed to have little impact on how health and disease are handled within the profession. Veterinary medicine would probably gain from theoretical discussions about health and disease.</p

Structural and functional insight into human O-GlcNAcase.

O-GlcNAc hydrolase (OGA) removes O-linked N-acetylglucosamine (O-GlcNAc) from a myriad of nucleocytoplasmic proteins. Through co-expression and assembly of OGA fragments, we determined the three-dimensional structure of human OGA, revealing an unusual helix-exchanged dimer that lays a structural foundation for an improved understanding of substrate recognition and regulation of OGA. Structures of OGA in complex with a series of inhibitors define a precise blueprint for the design of inhibitors that have clinical value

State history and economic development: evidence from six millennia

The presence of a state is one of the most reliable historical predictors of social and economic development. In this article, we complete the coding of an extant indicator of state presence from 3500 BCE forward for almost all but the smallest countries of the world today. We outline a theoretical framework where accumulated state experience increases aggregate productivity in individual countries but where newer or relatively inexperienced states can reach a higher productivity maximum by learning from the experience of older states. The predicted pattern of comparative development is tested in an empirical analysis where we introduce our extended state history variable. Our key finding is that the current level of economic development across countries has a hump-shaped relationship with accumulated state history

No Adverse Effect of Genetically Modified Antifungal Wheat on Decomposition Dynamics and the Soil Fauna Community – A Field Study

The cultivation of genetically modified (GM) plants has raised several environmental concerns. One of these concerns regards non-target soil fauna organisms, which play an important role in the decomposition of organic matter and hence are largely exposed to GM plant residues. Soil fauna may be directly affected by transgene products or indirectly by pleiotropic effects such as a modified plant metabolism. Thus, ecosystem services and functioning might be affected negatively. In a litterbag experiment in the field we analysed the decomposition process and the soil fauna community involved. Therefore, we used four experimental GM wheat varieties, two with a race-specific antifungal resistance against powdery mildew (Pm3b) and two with an unspecific antifungal resistance based on the expression of chitinase and glucanase. We compared them with two non-GM isolines and six conventional cereal varieties. To elucidate the mechanisms that cause differences in plant decomposition, structural plant components (i.e. C∶N ratio, lignin, cellulose, hemicellulose) were examined and soil properties, temperature and precipitation were monitored. The most frequent taxa extracted from decaying plant material were mites (Cryptostigmata, Gamasina and Uropodina), springtails (Isotomidae), annelids (Enchytraeidae) and Diptera (Cecidomyiidae larvae). Despite a single significant transgenic/month interaction for Cecidomyiidae larvae, which is probably random, we detected no impact of the GM wheat on the soil fauna community. However, soil fauna differences among conventional cereal varieties were more pronounced than between GM and non-GM wheat. While leaf residue decomposition in GM and non-GM wheat was similar, differences among conventional cereals were evident. Furthermore, sampling date and location were found to greatly influence soil fauna community and decomposition processes. The results give no indication of ecologically relevant adverse effects of antifungal GM wheat on the composition and the activity of the soil fauna community

Preselection and expert advice

"The final authenticated version is available online at https://doi.org/10.1007/s00182-016-0551-9We study the effects of preselection on an expert’s advice about the execution of a project if its execution yields more precise estimates about the expert’s expertise. The in troduction of a preselection stage, in which the decision maker evaluates the project before asking for advice, alters the expert’s perception of the problem. We identify conditions under which preselection occurs in equilibrium. We show that if the expert adjusts his behavior, the option to preselect may reduce the expected utility of the decision maker.Collaborative Research Center 88