90 research outputs found
Risk shifting consequences depending on manager characteristics
This paper investigates the performance consequences of the risk shifting behavior shown by domestic equity mutual funds through the analysis of monthly portfolio holdings. The objective of this paper is to assess the implications of risk shifting for mutual fund investors. Specifically, we study the performance consequences of different mechanisms of risk shifting, such as the change in the composition between equity and cash holdings and the change of the systematic or idiosyncratic risk within the equity positions. We find that funds that increase their risk level obtain significantly better performance than funds with stable or reduced risk levels. This finding is robust when controlling for fund characteristics such as past performance and fund size. Additionally, we examine whether the performance consequences of risk shifting depends on fund manager characteristics and find that manager gender, education and level of specialization are revealed as important variables to differentiate the performance consequences of risk shifting
The convergence between sustainability and conventional stock indices. Are we on the right track?
The growth of passive and socially responsible (SR) investment makes that sustainability indices play an important role in defining what constitutes a sustainable investment. In order to know the suitability of sustainability indices as benchmarks for SR investors, we used different linear regressions to compare the compositions of sustainability indices and their conventional counterparts and to compare the levels of corporate social responsibility (CSR) of both types of indices. We showed that the composition of sustainability indices gradually converged towards their conventional peers. Moreover, the difference between the CSR levels of both type of indices remained the same or even decreased over time. We concluded that a change in the weighting method of sustainability indices such as the equally weighted criterion would significantly increase the difference from their conventional counterparts. However, due to the relationship between CSR and size, this change would penalize the CSR level of the index. These results raise the question of whether SR passive investors will be able to meet their non-financial expectations as a consequence of the convergence. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Mutual fund performance attribution and market timing using portfolio holdings
We propose a novel performance attribution model for equity fund portfolios. The model analyses investment decisions based on portfolio holdings and measures the value added from different sources of performance such as past return strategies, security selection, market timing and passive timing. The model was tested for a sample of mutual funds. Empirical results show that security selection is the main contributor to fund performance regardless of the sample period considered or the asset pricing model used. The evidence of timing ability is mixed with low significance. Nevertheless there are noticeable differences between the timing ability of the best and worst performing funds, especially in crisis periods. Analysing the relationship between mutual fund performance (and its different components) and fund characteristics, we find that top funds are significantly smaller and more concentrated than other funds. Finally, we also examine the persistence in the performance and in its components finding evidence of positive persistence in past return strategies and picking skills although this persistence is not shown in the overall performance
Museum visitorsâ heterogeneity and experience processing
This research examines the relationships between affective and cognitive antecedents and consequences of satisfaction under a market heterogeneity approach. It includes co-creation of preparatory activities. The sample consisted of 276 museum visitors in London. Two analysis have been conducted: structural equation model and latent class path analysis. The paper contributes to the development of a theoretical framework for further understanding of service experience in which co-creation plays an important role. Two segments were identified: 1) emotional (with lower degree of co-creation, equally distributed by age and nationality); 2) rational (higher degree of co-creation, younger and domestic visitors). Our research shows significant differences between the two segments regarding variables such as satisfaction, loyalty, service experience, emotion, positive disconfirmation and willingness to pay more
NALP1 is a transcriptional target for cAMP-response-element-binding protein (CREB) in myeloid leukaemia cells
NALP1 (also called DEFCAP, NAC, CARD7) has been shown
to play a central role in the activation of inflammatory caspases
and processing of pro-IL1ÎČ (pro-interleukin-1ÎČ). Previous studies
showed that NALP1 is highly expressed in peripheral blood
mononuclear cells. In the present study, we report that expression
of NALP1 is absent from CD34+ haematopoietic blast cells,
and its levels are upregulated upon differentiation of CD34+
cells into granulocytes and to a lesser extent into monocytes.
In peripheral blood cells, the highest levels of NALP1 were
observed in CD3+ (T-lymphocytes), CD15+ (granulocytes) and
CD14+ (monocytes) cell populations. Notably, the expression of
NALP1 was significantly increased in the bone marrow blast
cell population of some patients with acute leukaemia, but not
among tissue samples from thyroid and renal cancer. A search for
consensus sites within the NALP1 promoter revealed a sequence
for CREB (cAMP-response-element-binding protein) that was
required for transcriptional activity. Moreover, treatment of TF1
myeloid leukaemia cells with protein kinase C and protein kinase
A activators induced CREB phosphorylation and upregulated
the mRNA and protein levels of NALP1. Conversely, ectopic
expression of a dominant negative form of CREB in TF1 cells
blocked the transcriptional activity of the NALP1 promoter and
significantly reduced the expression of NALP1. Thus NALP1
is transcriptionally regulated by CREB in myeloid cells, a
mechanism that may contribute to modulate the response of these
cells to pro-inflammatory stimuli
Lack of Bcr-Abl point mutations in chronic myeloid leukemia patients in chronic phase before imatinib treatment is not predictive of response
Imatinib inhibits proliferation of Ewing tumor cells mediated by the stem cell factor/KIT receptor pathway, and sensitizes cells to vincristine and doxorubicin-induced apoptosis
Purpose and Experimental Design: The stem cell factor/
KIT receptor loop may represent a novel target for molecular-
based therapies of Ewing tumor. We analyzed the in
vitro impact of KIT blockade by imatinib in Ewing tumor
cell lines.
Results: KIT expression was detected in 4 of 4 Ewing
tumor cell lines and in 49 of 110 patient samples (44.5%) by
immunohistochemistry and/or Western blot analysis. KIT
expression was stronger in Ewing tumors showing EWSFLI1
nontype 1 fusions. Despite absence of c-kit mutations,
constitutive and ligand-inducible phosphorylation of KIT
was found in all tumor cell lines, indicating an active receptor.
Treatment with KIT tyrosine kinase inhibitor imatinib
(0.5â20 M) induced down-regulation of KIT phosphorylation
and dose response inhibition of cell proliferation (IC50,
12â15 M). However, imatinib administered alone at doses
close to IC50 for growth inhibition (10 M) did not induce a
significant increase in apoptosis. We then analyzed if blockade
of KIT loop through imatinib (10 M) was able to
increase the antitumor in vitro effect of doxorubicin (DXR)and vincristine (VCR), drugs usually used in Ewing tumor
treatment. Addition of imatinib decreased in 15â20 and
15â36% of the proliferative rate of Ewing tumor cells exposed
to DXR and VCR, respectively, and increased in 15
and 30% of the apoptotic rate of Ewing tumor cells exposed
to the same drugs.
Conclusions: Inhibition of Ewing tumor cell proliferation
by imatinib is mediated through blockade of KIT receptor
signaling. Inhibition of KIT increases sensitivity of
these cells to DXR and VCR. This study supports a potential
role for imatinib in the treatment of Ewing tumor
Disease severity in familial cases of IBD
Background: Phenotypic traits of familial IBD relative to sporadic cases are controversial, probably related to limited statistical power of published evidence.
Aim: To know if there are phenotype differences between familial and sporadic IBD, evaluating the prospective Spanish registry (ENEIDA) with 11,983 cases.
Methods: 5783 patients (48.3%) had ulcerative colitis (UC) and 6200 (51.7%) Crohn's disease (CD). Cases with one or more 1st, 2nd or 3rd degree relatives affected by UC/CD were defined as familial case.
Results: In UC and CD, familial cases compared with sporadic cases had an earlier disease onset (UC: 33 years [IQR 25â44] vs 37 years [IQR 27â49]; p b 0.0001); (CD: 27 years [IQR 21â35] vs 29 years [IQR 22â40]; p b 0.0001), higher prevalence of extraintestinal immune-related manifestations (EIMs) (UC: 17.2% vs 14%; p = 0.04); (CD: 30.1% vs 23.6%; p b 0.0001). Familial CD had higher percentage of ileocolic location (42.7% vs 51.8%; p = 0.0001), penetrating behavior (21% vs 17.6%; p = 0.01) and perianal disease (32% vs 27.1%; p = 0.003). Differences are not influenced by degree of consanguinity.
Conclusion: When a sufficiently powered cohort is evaluated, familial aggregation in IBD is associated to an earlier disease onset, more EIMs and more severe phenotype in CD. This feature should be taken into account at establishing predictors of disease course
A CFD-DEM solver to model bubbly flow. Part I: Model development and assessment in upward vertical pipes
[EN] In the computational modeling of two-phase flow, many uncertainties are usually faced in simulations and validations with experiments. This has traditionally made it difficult to provide a general method to predict the two-phase flow characteristics for any geometry and condition, even for bubbly flow regimes. Thus, we focus our research on studying in depth the bubbly flow modeling and validation from a critical point of view. The conditions are intentionally limited to scenarios where coalescence and breakup can be neglected, to concentrate on the study of bubble dynamics and its interaction with the main fluid. This study required the development of a solver for bubbly flow with higher resolution level than TFM and a new methodology to obtain the data from the simulation. Part I shows the development of a solver based on the CFD-DEM formulation. The motion of each bubble is computed individually with this solver and aspects as inhomogeneity, nonlinearity of the interfacial forces, bubble-wall interactions and turbulence effects in interfacial forces are taken into account. To develop the solver, several features that are not usually required for traditional CFD-DEM simulations but are relevant for bubbly flow in pipes, have been included. Models for the assignment of void fraction into the grid, seeding of bubbles at the inlet, pressure change influence on the bubble size and turbulence effects on both phases have been assessed and compared with experiments for an upward vertical pipe scenario. Finally, the bubble path for bubbles of different size have been investigated and the interfacial forces analyzed. (C) 2017 Elsevier Ltd. All rights reserved.The authors sincerely thank the ''Plan Nacional de I + D+ i" for funding the project MODEXFLAT ENE2013-48565-C2-1-P and ENE2013-48565-C2-2-P.Peña-Monferrer, C.; Monrós Andreu, G.; Chiva Vicent, S.; Martinez-Cuenca, R.; Muñoz-Cobo, JL. (2018). A CFD-DEM solver to model bubbly flow. Part I: Model development and
assessment in upward vertical pipes. Chemical Engineering Science. 176:524-545. https://doi.org/10.1016/j.ces.2017.11.005S52454517
Light induced defects in thermal annealed hydrogenated amorphous silicon
The metastable defects of a-Si:H samples annealed at temperatures in the 300-550°C range have been studied by photothermal deflection spectroscopy (PDS). The light-soaked samples show an increase in optical absorption in the 0.8 to 1.5 eV range. The metastable defect density decreases when the annealing temperature increases, while the defect density increases. This decrease in the metastable defect density shows an almost linear correlation with the decrease in the hydrogen content of the samples, determined by IR transmission spectroscopy and thermal desorption spectroscopy
- âŠ