Search results for "C61"
showing 10 items of 16 documents
A Unified Approach to Portfolio Optimization with Linear Transaction Costs
2004
In this paper we study the continuous time optimal portfolio selection problem for an investor with a finite horizon who maximizes expected utility of terminal wealth and faces transaction costs in the capital market. It is well known that, depending on a particular structure of transaction costs, such a problem is formulated and solved within either stochastic singular control or stochastic impulse control framework. In this paper we propose a unified framework, which generalizes the contemporary approaches and is capable to deal with any problem where transaction costs are a linear/piecewise-linear function of the volume of trade. We also discuss some methods for solving numerically the p…
Monotone Concave Operators: An application to the existence and uniqueness of solutions to the Bellman equation
2008
We propose a new approach to the issue of existence and uniqueness of solutions to the Bellman equation, exploiting an emerging class of methods, called monotone map methods, pioneered in the work of Krasnosel’skii (1964) and Krasnosel’skii-Zabreiko (1984). The approach is technically simple and intuitive. It is derived from geometric ideas related to the study of fixed points for monotone concave operators defined on partially order spaces.
- SHADOW PRICES AND DISTANCE FUNCTIONS: AN ANALYSIS FOR FIRMS OF THE SPANISH CERAMIC PAVEMENTS INDUSTRY.
1999
This paper deals with the calculation of shadow prices for two industrial wastes generated on their production processes by a sample of eighteen firms belonging to the Spanish ceramic pavements industry. These prices are used to construct a corrected index of productivity which allows for considering wastes going with the production of marketable goods. It is followed the ethodologicalapproach first proposed by Färe, Grosskopf, Lovell y Yaisawarng (1993), which establishes a duality between distance and revenue functions. The shadow prices obtained for watery muds and used oils allow to measure in terms of a loss of marketable output the cost of achieving a marginal reduction in the product…
Report of the Scientific Committee of the Spanish Agency for Food Safety and Nutrition (AESAN) on the presence and safety of plastics as contaminants…
2020
* This record is given in both English and Spanish. The use of plastics is widespread in both industry and domestic life as food packaging material and as a material that comes into contact with food. Therefore, plastics and their environmental impact, especially in the marine environment, arouse great interest and concern. Microplastics have been the focus of most of the studies carried out so far due to their growing presence in the natural environment and their potential to be transferred between trophic levels. It is necessary not only to make an exhaustive assessment of the presence of microplastics in the environment and food, but also of their effects on human’s health. This report a…
European Option Pricing and Hedging with Both Fixed and Proportional Transaction Costs
2003
Abstract In this paper we provide a systematic treatment of the utility based option pricing and hedging approach in markets with both fixed and proportional transaction costs: we extend the framework developed by Davis et al. (SIAM J. Control Optim., 31 (1993) 470) and formulate the option pricing and hedging problem. We propose and implement a numerical procedure for computing option prices and corresponding optimal hedging strategies. We present a careful analysis of the optimal hedging strategy and elaborate on important differences between the exact hedging strategy and the asymptotic hedging strategy of Whalley and Wilmott (RISK 7 (1994) 82). We provide a simulation analysis in order …
Membrane protein integration into the endoplasmic reticulum
2011
Most integral membrane proteins are targeted, inserted and assembled in the endoplasmic reticulum membrane. The sequential and potentially overlapping events necessary for membrane protein integration take place at sites termed translocons, which comprise a specific set of membrane proteins acting in concert with ribosomes and, probably, molecular chaperones to ensure the success of the whole process. In this minireview, we summarize our current understanding of helical membrane protein integration at the endoplasmic reticulum, and highlight specific characteristics that affect the biogenesis of multispanning membrane proteins.
Revisiting the quiet life hypothesis in banking using nonparametric techniques
2014
Early studies testing the quiet life hypothesis in banking found strong evidence that banks in more concentrated markets exhibit lower cost efficiency levels. More recent studies have reexamined the issue in different contexts, with mixed results. These approaches are based on stipulating a linear re- lationship between market power and efficiency in banking, which might be problematic, as suggested by the literature on efficiency analysis. We explore how bank cost efficiency measures are related to market power using flexible techniques, which are more consistent with those employed to measure efficiency in the first stage of the analysis. Our study focuses on the Spanish banking industry,…
Can we be satisfied with our football team? Evidence from spanish professional football.
2009
This article assesses the sporting performance of Spanish professional football teams at competition level, namely, League, King’s Cup, and European competitions (Champions League and Union of European Football Associations [UEFA] Cup). Then, the gap between the result obtained by a team at the end of a season and that expected according to its potential is used as a proxy of the degree of satisfaction that fans should feel: the narrower the gap the greater the level of satisfaction. Regarding methodology, Data Envelopment Analysis techniques and directional distance functions are used. Results reveal that most teams perform rather differently across competitions, the lower average performa…
Targeting and membrane insertion into the endoplasmic reticulum membrane of Saccharomyces cerevisiae essential protein Rot1
2010
Rot1 is an essential yeast protein that has been related to cell wall biosynthesis, actin cytoskeleton dynamics and protein folding. Rot1 is an N -glycosylated protein anchored to the nuclear envelope–endoplasmic reticulum (ER) membrane by a transmembrane domain at its C-terminal end. Rot1 is translocated to the ER by a post-translational mechanism. Here, we investigate the protein domain required to target and translocate Rot1 to the ER membrane. We found that several deletions of the N-terminal region of Rot1 prevented neither membrane targeting nor the insertion of this protein. Interestingly, we obtained the same results when different truncated forms in the C-terminal transmembrane dom…
Role of Human Sec63 in Modulating the Steady-State Levels of Multi-Spanning Membrane Proteins
2012
The Sec61 translocon of the endoplasmic reticulum (ER) membrane forms an aqueous pore, allowing polypeptides to be transferred across or integrated into membranes. Protein translocation into the ER can occur co- and posttranslationally. In yeast, posttranslational translocation involves the heptameric translocase complex including its Sec62p and Sec63p subunits. The mammalian ER membrane contains orthologs of yeast Sec62p and Sec63p, but their function is poorly understood. Here, we analyzed the effects of excess and deficit Sec63 on various ER cargoes using human cell culture systems. The overexpression of Sec63 reduces the steady-state levels of viral and cellular multi-spanning membrane …