Investment Strategies, Fund Performance and Portfolio Characteristics

This paper studies the relation between fund performance and the fund manager's investment strategy, which is based on the characteristics of the portfolio. The results show that neither momentum characteristics nor the valuation of stocks can explain differences in fund performance. However, the paper finds a negative firm-size effect that partly explains previous findings of a negative fund-size effect. Moreover, the results show a positive relation between performance and the degree of diversification within the fund portfolio. However, diversification by including non-listed stocks does not enhance performance.Diversification; Portfolio Evaluation; Investment Strategies; Momentum

Does Active Portfolio Management Create Value? An Evaluation of Fund Managers' Decisions

In this paper, I obtain new measures of the value of active portfolio management by forming replicating portfolios. These measures allow for a separate evaluation of fund managers' strategic and tactical decisions. I also obtain new evidence on the value of trading by decomposing it into long-term trading decisions, short-term trading decisions, and trading that is the result of regulatory restrictions. Overall, the evidence supports the value of active portfolio management and that the average fund manager creates value for its investors. Moreover, the results show a positive relation between the value created and trading activity.Mutual Funds; Portfolio Evaluation; Performance Attribution; Trading

Information Costs and Mutual Fund Flows

This paper examines how investor and capital flows into mutual funds in the Swedish pension system are related to fund characteristics. Similarly to U.S. studies, we show that individuals chase past returns and have a strong preference for lower-fee funds. However, our results suggest that past returns are less important than previous studies suggest. A more important determinant of fund inflows is information costs. For instance, foreign-based funds with a track record similar to that of domestic funds attract fewer investors and receive less capital. Moreover, new funds without a track record also receive lower inflows.Flows; Information; Pension System; Portfolio Choice

Investment strategies, fund performance and portfolio characteristics

This paper studies the relation between fund performance and the fund manager's investment strategy, which is based on the characteristics of the portfolio. The results show that neither momentum characteristics nor the valuation of stocks can explain differences in fund performance. However, the paper finds a negative firm-size effect that partly explains previous findings of a negative fund-size effect. Moreover, the results show a positive relation between performance and the degree of diversification within the fund portfolio. However, diversification by including non-listed stocks does not enhance performance

Does active portfolio management create value? An evaluation of fund managers' decisions

In this paper, I obtain new measures of the value of active portfolio management by forming replicating portfolios. These measures allow for a separate evaluation of fund managers' strategic and tactical decisions. I also obtain new evidence on the value of trading by decomposing it into long-term trading decisions, short-term trading decisions, and trading that is the result of regulatory restrictions. Overall, the evidence supports the value of active portfolio management and that the average fund manager creates value for its investors. Moreover, the results show a positive relation between the value created and trading activity

Information costs and mutual fund flows

This paper examines how investor and capital flows into mutual funds in the Swedish pension system are related to fund characteristics. Similarly to U.S. studies, we show that individuals chase past returns and have a strong preference for lower-fee funds. However, our results suggest that past returns are less important than previous studies suggest. A more important determinant of fund inflows is information costs. For instance, foreign-based funds with a track record similar to that of domestic funds attract fewer investors and receive less capital. Moreover, new funds without a track record also receive lower inflows

Nitrogen removal in marine environments: recent findings and future research challenges

Respiratory reduction of nitrate (denitrification) is recognized as the most important process converting biologically available (fixed) nitrogen to N2. In current N cycle models, a major proportion of global marine denitrification (50–70%) is assumed to take place on the sea floor, particularly in organic rich continental margin sediments. Recent observations indicate that present conceptual views of denitrification and pathways of nitrate reduction and N2 formation are incomplete. Alternative N cycle pathways, particularly in sediments, include anaerobic ammonium oxidation to nitrite, nitrate and N2 by Mn-oxides, and anaerobic ammonium oxidation coupled to nitrite reduction and subsequent N2 mobilization. The discovery of new links and feedback mechanisms between the redox cycles of, e.g., C, N, S, Mn and Fe casts doubt on the present general understanding of the global N cycle. Recent models of the oceanic N budget indicate that total inputs are significantly smaller than estimated fixed N removal. The occurrence of alternative N reaction pathways further exacerbates the apparent imbalance as they introduce additional routes of N removal. In this contribution, we give a brief historical background of the conceptual understanding of N cycling in marine ecosystems, emphasizing pathways of aerobic and anaerobic N mineralization in marine sediments, and the implications of recently recognized metabolic pathways for N removal in marine environments

Digital transcriptome profiling of normal and glioblastoma-derived neural stem cells identifies genes associated with patient survival.

BACKGROUND: Glioblastoma multiforme, the most common type of primary brain tumor in adults, is driven by cells with neural stem (NS) cell characteristics. Using derivation methods developed for NS cells, it is possible to expand tumorigenic stem cells continuously in vitro. Although these glioblastoma-derived neural stem (GNS) cells are highly similar to normal NS cells, they harbor mutations typical of gliomas and initiate authentic tumors following orthotopic xenotransplantation. Here, we analyzed GNS and NS cell transcriptomes to identify gene expression alterations underlying the disease phenotype. METHODS: Sensitive measurements of gene expression were obtained by high-throughput sequencing of transcript tags (Tag-seq) on adherent GNS cell lines from three glioblastoma cases and two normal NS cell lines. Validation by quantitative real-time PCR was performed on 82 differentially expressed genes across a panel of 16 GNS and 6 NS cell lines. The molecular basis and prognostic relevance of expression differences were investigated by genetic characterization of GNS cells and comparison with public data for 867 glioma biopsies. RESULTS: Transcriptome analysis revealed major differences correlated with glioma histological grade, and identified misregulated genes of known significance in glioblastoma as well as novel candidates, including genes associated with other malignancies or glioma-related pathways. This analysis further detected several long non-coding RNAs with expression profiles similar to neighboring genes implicated in cancer. Quantitative PCR validation showed excellent agreement with Tag-seq data (median Pearson r = 0.91) and discerned a gene set robustly distinguishing GNS from NS cells across the 22 lines. These expression alterations include oncogene and tumor suppressor changes not detected by microarray profiling of tumor tissue samples, and facilitated the identification of a GNS expression signature strongly associated with patient survival (P = 1e-6, Cox model). CONCLUSIONS: These results support the utility of GNS cell cultures as a model system for studying the molecular processes driving glioblastoma and the use of NS cells as reference controls. The association between a GNS expression signature and survival is consistent with the hypothesis that a cancer stem cell component drives tumor growth. We anticipate that analysis of normal and malignant stem cells will be an important complement to large-scale profiling of primary tumors.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Prevalence of knee pain and knee OA in southern Sweden and the proportion that seeks medical care.

The aim of this study was to estimate the prevalence of frequent knee pain in radiographic, symptomatic and clinically defined knee OA in middle-aged and elderly patients and the proportion that seeks medical care

Carbon-Based Nanoelectromechanical Devices

Carbon-based nanoelectromechanical devices are approaching applications in electronics. Switches based on individual carbon nanotubes deliver record low off-state leakage currents. Arrays of vertically aligned carbon nanotubes or nanofibers can be fabricated to constitute varactors. Very porous, low density arrays of quasi-vertically aligned arrays of carbon nanotubes behave mechanically as a single unit with very unusual material properties