4,185 research outputs found
Geographic versus industry diversification: constraints matter
This research addresses whether geographic diversification provides benefits over industry diversification. In the absence of constraints, no empirical evidence is found to support the argument that country diversification is superior. With short-selling constraints, however, the geographic tangency portfolio is not attainable by industry portfolios. Results with upper and lower constraints on portfolio weights as well as an out-of-sample analysis show that geographic diversification almost consistently outperforms industry portfolios, although we cannot establish statistical significance. JEL Classification: G11, G15block-bootstrap tests, Diversification gains, EMU, geographic diversification, industry diversification
Geographical versus Industrial Diversification: A Mean Variance Spanning Approach
This paper addresses whether country allocation provides benefits over industry allocation in a sample of European country and industry indexes. Strategy performance is compared using a mean-variance spanning test. We find that, for investors with low risk aversion, industry allocation is as good as investing in the complete set of assets. Moreover, in the most recent subperiod coinciding with the inception of the Euro, country and industry diversification are both effective. By contrast, investors with high risk aversion should always mix country and industry portfolios. A striking aspect of our analysis is that we do not find empirical evidence to support the argument that country diversification is a superior approach.Diversification gains, EMU, mean-variance spanning, portfolio allocation strategies
Recommended from our members
Low income as a determinant of exercise capacity in COPD.
Exercise capacity (EC) is a critical outcome in chronic obstructive lung disease (chronic obstructive pulmonary disease (COPD)). It measures the impact of the disease and the effect of specific interventions like pulmonary rehabilitation (PR). EC determines COPD prognosis and is associated with health-care utilization and quality of life. Field walking tests and cardiopulmonary exercise test (CPET) are two ways to measure EC. The 6-minute walking test (6MWT) is the commonest and easiest field test. CPET has the advantage of assessing maximal aerobic capacity. Determinants of EC include age, gender, breathlessness, and lung function. Previous research suggests that socioeconomic status (SES), a meaningful factor in COPD, may also be associated with EC. However, those findings have not been replicated. We aimed to determine whether SES is an independent factor associated with EC in COPD. For this analysis, we used the National Emphysema Treatment Trial (NETT) database. NETT was a multicenter clinical trial where severe COPD patients were randomized to lung volume reduction surgery or medical therapy. Measures used were taken at baseline, postrehabilitation. Patients self-reported their income and were divided in two groups whether it was less or above US$30,000. Patients with a lower income had worse results in 6MWT ( p < 0.0001). We found an independent association between income and the 6MWT in patients with severe COPD after adjusting for age, gender, lung function, dyspnea, and living conditions ( p < 0.0007). One previous publication stated the relationship between income and EC. Our research confirms and extends previous publications associating EC with income by studying a large and well characterized cohort of severe COPD patients, also addressing EC by two different methods (maximal watts and 6MWT). Our results highlight the importance of addressing social determinants of health such as income when assessing COPD patients
An Architecture for Provenance Systems
This document covers the logical and process architectures of provenance systems. The logical architecture identifies key roles and their interactions, whereas the process architecture discusses distribution and security. A fundamental aspect of our presentation is its technology-independent nature, which makes it reusable: the principles that are exposed in this document may be applied to different technologies
Geographic versus industry diversification: constraints matter
This research addresses whether geographic diversification provides benefits over industry diversification. In the absence of constraints, no empirical evidence is found to support the argument that country diversification is superior. With short-selling constraints, however, the geographic tangency portfolio is not attainable by industry portfolios. Results with upper and lower constraints on portfolio weights as well as an out-of-sample analysis show that geographic diversification almost consistently outperforms industry portfolios, although we cannot establish statistical significance
Tyrosine Kinase Inhibitors for Non-Small Cell Lung Cancer and Eye Metastasis: Disease Relapse or a New Entity?
Lung cancer is still diagnosed during the advanced stage of the disease and most patients do not have the opportunity for surgical treatment, despite the new diagnostic equipment that has been made available in recent years, such as the radial and linear endobronchial ultrasound (EBUS) and electromagnetic fiberoptic bronchoscopy. However, novel targeted therapies with second generation tyrosine kinase inhibitors and immunotherapy are available. In this commentary, we will focus on eye metastasis after initiation of tyrosine kinase inhibitors due to epidermal growth factor mutation of lung cancer adenocarcinoma.Ă
Targeted Lung Cancer Treatments and Eye Metastasis
Lung cancer remains the leading cause of death due to cancer. We do not have effective tools for the early detection of lung cancer, so patients are usually diagnosed at an advanced stage. However, novel therapies based on molecular pathways (such as those involving the epidermal growth factor receptor, anaplastic lymphoma kinase, serine/threonine-protein kinase B-Raf, proto-oncogene tyrosine-protein kinase ROS, c-Met proto-oncogene protein, and RET proto-oncogene protein) are now commonly used in the treatment of lung cancer. In particular, these therapies are considered as first-line treatments for non-small-cell lung cancer. This manuscript outlines previous research on these targeted treatments, focusing on whether they are effective against eye metastasis
Examining biofilm growth and metabolism of Escherichia coli at laboratory scale using geoelectrical methods
To link geophysical field data to specific biological phenomena, controlled laboratory experiments are needed for the understanding of the response of geophysical parameters to changes in biological conditions. In this study, suspensions of bacteria were mixed with sand to create a biofilm growing on a surface and these mixtures were monitored using the geoelectrical spectral induced polarization method (SIP). The beginning growth of the biofilm was confirmed by scanning electron microscopy and the amount of bacteria in liquid and sand estimated using culture and DNA based methods (i.e. qPCR, quantitative polymerase chain reaction). While changes in SIP signal could not be clearly related to microbial activity, fluctuations in the phase shift were concomitant with the detection of two unidentified metabolites in the liquid extracted from the sand. These metabolites were only detected when the biofilm was produced under oxygen limiting conditions. Even though the experimental design was not optimal for the SIP measurements, the results support the idea that these measurements are not measuring cell mass but are influenced by the presence of smaller charged molecules that may be produced as microbial metabolites. As microbial metabolites would change in the field during bioremediation, this method could be applied for this type of monitoring
- âŠ