141 research outputs found

    A study of data-driven momentum and disposition effects in the Chinese stock market by functional data analysis

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    We apply a functional data analysis approach to decompose the cross-sectional Fama–French three-factor model residuals in the Chinese stock market. Our results indicate that other than Fama–French three factors, there are two orthonormal asset pricing factors describing the behavioral biases in their historical performances: between winner and loser stocks, and extreme and mediocre-performing stocks, respectively. We explain these two factors through investors’ overreaction, overconfidence and the lead-lag effect. These findings empirically show the existence of momentum and disposition effects in the Chinese stock market. A buy-and-hold mean-variance optimized portfolio incorporating these two market anomalies boosts the Sharpe ratio to 1.27

    Intravenous Immunoglobulin Prevents Murine Antibody-Mediated Acute Lung Injury at the Level of Neutrophil Reactive Oxygen Species (ROS) Production

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    Transfusion-related acute lung injury (TRALI) is a leading cause of transfusion-associated mortality that can occur with any type of transfusion and is thought to be primarily due to donor antibodies activating pulmonary neutrophils in recipients. Recently, a large prospective case controlled clinical study of cardiac surgery patients demonstrated that despite implementation of male donors, a high incidence of TRALI still occurred and suggested a need for additional interventions in susceptible patient populations. To examine if intravenous immunoglobulin (IVIg) may be effective, a murine model of antibody-mediated acute lung injury that approximates human TRALI was examined. When BALB/c mice were injected with the anti-major histocompatibility complex class I antibody 34-1-2s, mild shock (reduced rectal temperature) and respiratory distress (dyspnea) were observed and pre-treatment of the mice with 2 g/kg IVIg completely prevented these symptoms. To determine IVIg's usefulness to affect severe lung damage, SCID mice, previously shown to be hypersensitive to 34-1-2s were used. SCID mice treated with 34-1-2s underwent severe shock, lung damage (increased wet/dry ratios) and 40% mortality within 2 hours. Treatment with 2 g/kg IVIg 18 hours before 34-1-2s administration completely protected the mice from all adverse events. Treatment with IVIg after symptoms began also reduced lung damage and mortality. While the prophylactic IVIg administration did not affect 34-1-2s-induced pulmonary neutrophil accumulation, bone marrow-derived neutrophils from the IVIg-treated mice displayed no spontaneous ROS production nor could they be stimulated in vitro with fMLP or 34-1-2s. These results suggest that IVIg prevents murine antibody-mediated acute lung injury at the level of neutrophil ROS production and thus, alleviating tissue damage

    From Poverty to Disaster and Back: a Review of the Literature

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    Poor people are disproportionally affected by natural hazards and disasters. This paper provides a review of the multiple factors that explain why this is the case. It explores the role of exposure (often, but not always, poor people are more likely to be affected by hazards), vulnerability (when they are affected, poor people tend to lose a larger fraction of their wealth), and socio-economic resilience (poor people have a lower ability to cope with and recover from disaster impacts). Finally, the paper highlights the vicious circle between poverty and disaster losses: poverty is a major driver of people’s vulnerability to natural disasters, which in turn increase poverty in a measurable and significant way. The main policy implication is that poverty reduction can be considered as disaster risk management, and disaster risk management can be considered as poverty reduction

    High efficiency of alphaviral gene transfer in combination with 5-fluorouracil in a mouse mammary tumor model

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    Copyright: Copyright 2014 Elsevier B.V., All rights reserved.Background: The combination of virotherapy and chemotherapy may enable efficient tumor regression that would be unachievable using either therapy alone. In this study, we investigated the efficiency of transgene delivery and the cytotoxic effects of alphaviral vector in combination with 5-fluorouracil (5-FU) in a mouse mammary tumor model (4 T1).Methods: Replication-deficient Semliki Forest virus (SFV) vectors carrying genes encoding fluorescent proteins were used to infect 4 T1 cell cultures treated with different doses of 5-FU. The efficiency of infection was monitored via fluorescence microscopy and quantified by fluorometry. The cytotoxicity of the combined treatment with 5-FU and alphaviral vector was measured using an MTT-based cell viability assay. In vivo experiments were performed in a subcutaneous 4 T1 mouse mammary tumor model with different 5-FU doses and an SFV vector encoding firefly luciferase.Results: Infection of 4 T1 cells with SFV prior to 5-FU treatment did not produce a synergistic anti-proliferative effect. An alternative treatment strategy, in which 5-FU was used prior to virus infection, strongly inhibited SFV expression. Nevertheless, in vivo experiments showed a significant enhancement in SFV-driven transgene (luciferase) expression upon intratumoral and intraperitoneal vector administration in 4 T1 tumor-bearing mice pretreated with 5-FU: here, we observed a positive correlation between 5-FU dose and the level of luciferase expression.Conclusions: Although 5-FU inhibited SFV-mediated transgene expression in 4 T1 cells in vitro, application of the drug in a mouse model revealed a significant enhancement of intratumoral transgene synthesis compared with 5-FU untreated mice. These results may have implications for efficient transgene delivery and the development of potent cancer treatment strategies using alphaviral vectors and 5-FU.publishersversionPeer reviewe

    Anti-cancer drug validation: the contribution of tissue engineered models

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    Abstract Drug toxicity frequently goes concealed until clinical trials stage, which is the most challenging, dangerous and expensive stage of drug development. Both the cultures of cancer cells in traditional 2D assays and animal studies have limitations that cannot ever be unraveled by improvements in drug-testing protocols. A new generation of bioengineered tumors is now emerging in response to these limitations, with potential to transform drug screening by providing predictive models of tumors within their tissue context, for studies of drug safety and efficacy. Considering the NCI60, a panel of 60 cancer cell lines representative of 9 different cancer types: leukemia, lung, colorectal, central nervous system (CNS), melanoma, ovarian, renal, prostate and breast, we propose to review current Bstate of art^ on the 9 cancer types specifically addressing the 3D tissue models that have been developed and used in drug discovery processes as an alternative to complement their studyThis article is a result of the project FROnTHERA (NORTE-01-0145-FEDER-000023), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This article was also supported by the EU Framework Programme for Research and Innovation HORIZON 2020 (H2020) under grant agreement n° 668983 — FoReCaST. FCT distinction attributed to Joaquim M. Oliveira (IF/00423/2012) and Vitor M. Correlo (IF/01214/2014) under the Investigator FCT program is also greatly acknowledged.info:eu-repo/semantics/publishedVersio

    2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.

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    Quality-of-life indicators and falls due to vitamin D deficiency

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    Muhammad Raza Cheema, Ahmad Yar Chaudhry Department of Geriatrics, University Hospitals Coventry and Warwickshire, NHS Hospitals, Coventry, UK Objective: To determine whether the number of falls and quality-of-life indicators relate to serum levels of vitamin D, parathyroid hormone (PTH), and calcium levels.Design: A prospective study.Participants: Patients being admitted with a fall with or without sustaining a fragility fracture post fall.Measurements: Measured frequency of falling, SF-12 questionnaire, serum concentrations of 25-hydroxyvitamin D, calcium, and PTH levels before and after treatment with vitamin D supplementation.Results: The mean age (N=38) of the cohort was 80.2±12. In all, 76.3% of the cohort had sustained a fragility fracture after the fall. The cohort was vitamin D deficient with the pretreatment mean value of 24.2±17 nmol/L and posttreatment mean value of 99±40 nmol/L with a statistically significant mean difference of 74.7 nmol/L (confidence interval [CI] 61.27–88.3), P=0.001. The levels of calcium and PTH were statistically significant after treatment with a mean difference of 0.16 (CI 0.1–0.2), P=0.001, and 3.7 (CI –4.8 to –2.5), P=0.001, respectively. After treatment, the mean difference of physical component score (PCS) and mental component score for the whole cohort was 2.9 (CI –0.69 to 6.6), P=0.10, and 1.05 (CI –2.6 to 4.7), P=0.56, respectively. However, a subgroup analysis for cohort aged ≤70 years provided a statistically significant effect on PCS with a mean difference of 8.9 (CI 1.3–16.4), P=0.03, but a statistically insignificant improvement in mental component score with a mean difference of 6.0 (CI –17 to –5.0), P=0.20. However, a statistically significant improvement in PCS SF-12 was observed in patients ≤70 years of age 2.9 (1.3–16.4), P=0.03. The mean number of falls for the whole cohort pre- and posttreatment was 1.11±0.92 vs 0.97±0.99 (P=0.68), respectively.Conclusion: Patients who had fallen and sustained fragility fracture had lower serum 25-dihydroxyvitamin D and higher serum PTH levels. Our study demonstrates that there is no statistically significant improvement in the number of falls after treatment with vitamin D. Overall, vitamin D levels improved significantly, this is despite quality-of-life indicators showing a mean increase in PCS but not a statistically significant improvement. However, statistically significant improvement in PCS was observed in group aged ≤70 years after vitamin D supplementation. Keywords: vitamin D, calcium, SF-12 questionnaire, parathyroid hormon
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