Limits to Arbitrage when Market Participation Is Restricted

There is an extensive litarature claiming that it is often difficult to make use of arbitrage opportunities in financial markets. This paper provides a new reason why existing arbitrage opportunities might not be seized. We consider a world with short-lived securities, no short-selling constraints and no transaction costs. We show that to exploit all existing arbitrage opportunities, traders should pay attention to all financial markets simultaneously. It gives a general result stating that failure to do so will leave some arbitrage opportunities unexploited with probability one.microeconomics ;

Automatic Sentiment Analysis in On-line Text

The growing stream of content placed on the Web provides a huge collection of textual resources. People share their experiences on-line, ventilate their opinions (and frustrations), or simply talk just about anything. The large amount of available data creates opportunities for automatic mining and analysis. The information we are interested in this paper, is how people feel about certain topics. We consider it as a classification task: their feelings can be positive, negative or neutral. A sentiment isn't always stated in a clear way in the text; it is often represented in subtle, complex ways. Besides direct expression of the user's feelings towards a certain topic, he or she can use a diverse range of other techniques to express his or her emotions. On top of that, authors may mix objective and subjective information about a topic, or write down thoughts about other topics than the one we are investigating. Lastly, the data gathered from the World Wide Web often contains a lot of noise. All of this makes the task of automatic recognition of the sentiment in on-line text more difficult. We will give an overview of various techniques used to tackle the problems in the domain of sentiment analysis, and add some of our own results

Corporate Social Responsibility in a context of sustainable development

“The future we want”, the main document summarizing the action areas advocated by the Rio+20 conference (Rio de Janeiro, Brazil, June 20-22nd), advocates “green economy” as a main instrument to eradicate poverty, while maintaining the healthy functioning of the environment. “Green economy” is a reply to global capitalism and the excesses of its elite practitioners, as they became manifest during the recent economic crisis. A classical contribution of the private business sector to sustainable development is corporate social responsibility (CSR). The concept dovetails in the doctrine that a company is not only responsible for a positive economic performance, but also has to take care about the environmental, social and ethical aspects of its activities. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3164

Comprehensive embryo testing. Experts opinions regarding future directions: an expert panel study on comprehensive embryo testing

What do scientists in the field of preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS) consider to be the future direction of comprehensive embryo testing? Although there are many biological and technical limitations, as well as uncertainties regarding the meaning of genetic variation, comprehensive embryo testing will impact the IVF/PGD practice and a timely ethical reflection is needed. Comprehensive testing using microarrays is currently being introduced in the context of PGD and PGS, and it is to be expected that whole-genome sequencing will also follow. Current ethical and empirical sociological research on embryo testing focuses on PGD as it is practiced now. However, empirical research and systematic reflection regarding the impact of comprehensive techniques for embryo testing is missing. In order to understand the potential of this technology and to be able to adequately foresee its implications, we held an expert panel with seven pioneers in PGD. We conducted an expert panel in October 2011 with seven PGD pioneers from Belgium, The Netherlands, Germany and the UK. Participants expected the use of comprehensive techniques in the context of PGD. However, the introduction of these techniques in embryo testing requires timely ethical reflection as it involves a shift from choosing an embryo without a particular genetic disease (i.e. PGD) or most likely to result in a successful pregnancy (i.e. PGS) to choosing the best embryo based on a much wider set of criteria. Such ethical reflection should take account of current technical and biological limitations and also of current uncertainties with regard to the meaning of genetic variance. However, ethicists should also not be afraid to look into the future. There was a general agreement that embryo testing will be increasingly preceded by comprehensive preconception screening, thus enabling smart combinations of genetic testing. The group was composed of seven participants from four Western Europe countries. As willingness to participate in this study may be connected with expectations regarding the pace and direction of future developments, selection bias cannot be excluded. The introduction of comprehensive screening techniques in embryo testing calls for further ethical reflection that is grounded in empirical work. Specifically, there is a need for studies querying the opinions of infertile couples undergoing IVF/PGS regarding the desirability of embryo screening beyond aneuploidy. This research was supported by the CSG, Centre for Society and Life Sciences (project number: 70.1.074). The authors declare no conflict of interest. N/A

The social contact hypothesis under the assumption of endemic equilibrium: Elucidating the transmission potential of VZV in Europe.

The basic reproduction number R0 and the effective reproduction number R are pivotal parameters in infectious disease epidemiology, quantifying the transmission potential of an infection in a population. We estimate both parameters from 13 pre-vaccination serological data sets on varicella zoster virus (VZV) in 12 European countries and from population-based social contact surveys under the commonly made assumptions of endemic and demographic equilibrium. The fit to the serology is evaluated using the inferred effective reproduction number R as a model eligibility criterion combined with AIC as a model selection criterion. For only 2 out of 12 countries, the common choice of a constant proportionality factor is sufficient to provide a good fit to the seroprevalence data. For the other countries, an age-specific proportionality factor provides a better fit, assuming physical contacts lasting longer than 15 min are a good proxy for potential varicella transmission events. In all countries, primary infection with VZV most often occurs in early childhood, but there is substantial variation in transmission potential with R0 ranging from 2.8 in England and Wales to 7.6 in The Netherlands. Two non-parametric methods, the maximal information coefficient (MIC) and a random forest approach, are used to explain these differences in R0 in terms of relevant country-specific characteristics. Our results suggest an association with three general factors: inequality in wealth, infant vaccination coverage and child care attendance. This illustrates the need to consider fundamental differences between European countries when formulating and parameterizing infectious disease models

Surprising findings following a Belgian food contamination with polychlorobiphenyls and dioxins.

We found that 12.1% of Belgian export meat samples from chicken or pork, unrelated to the PCB/dioxin crisis from 1999, contained more than 50 ng polychlorinated biphenyls (PCBs)/g fat and that 6.5% of samples contain more than 20 ng/g fat for the sum of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its metabolites. Part of this background contamination stems from imported animal feed ingredients (fish flour and grains), sometimes contaminated by recent use of DDT, as can be deduced from the ratio between DDT and its main metabolite, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE). However, after comparing PCB concentrations in fish flour and grains with those found in meat, we suggest that the high concentrations stem from recycled fat. This is the first paper describing background concentrations of PCBs in animal meat from Belgium