1,482 research outputs found
Assessing sentiment timing ability and mutual fund manager skill
We develop a method that can statistically identify fund managers that exhibit selectivity in their trades, and find that occurrences of good and bad selectivity exceed random expectation. Mutual funds exhibit selectivity by tilting their portfolios towards the better performing stocks when they buy (sell) stocks with high sentiment betas preceding an increase (decrease) in investor sentiment. Conversely, funds that incorrectly time investor sentiment exhibit bad stock selection, explaining the above random incidence of this behavior. Our method can distinguish skill from fortuitous stock selection, and provides a practical tool for evaluating the performance of fund managers
The relation between financial development, energy consumption and economic growth: empirical evidence for the United States
This paper examines the relation between financial development, energy consumption and economic growth in the United States (U.S) for the period 1966-2011. We use a vector error correction model (VECM) to investigate the effect of financial development and energy consumption on economic growth in the U.S. In addition to examining the relation in the long run of the aforementioned variables using Johansen co-integration analysis, we also examine the short-run and long-run causalities between them. In addition to economic growth, financial development and energy consumption variables, we also examine the impact of real interest rate, gross fixed capital formation and trade openness on economic growth. We find that there is at least one co-integrating relation among the variables. There is some evidence that in the long run financial development causes economic growth; however, there is no evidence that economic growth causes financial development. Neither do we find evidence that financial development positively affects energy consumption either in the short- or long-run. However, in the short run, we find some evidence of two-way causality between economic growth and financial development
Does selectivity in mutual fund trades exploit sentiment timing?
In this study, we develop a method that can statistically identify fund managers that exhibit selectivity in their trades and find that occurrences of good and bad selectivity exceed random expectation. Mutual fund managers exhibit selectivity by tilting their portfolios toward better performing stocks when they buy (sell) stocks with high sentiment betas preceding an increase (decrease) in investor sentiment. Conversely, funds that incorrectly time investor sentiment exhibit bad stock selection, explaining the above random incidence of this behavior. Our method distinguishes skill from fortuitous stock selection and provides a practical tool for evaluating the performance of fund managers
Innovation in smallholder farming in Africa: recent advances and recommendations: Proceedings of the International Workshop on Agricultural Innovation Systems in Africa (AISA)
In the wake of a series of recent international events and initiatives focusing on understanding and fostering innovation1, there is growing awareness and interest in applying and making sense of the Agricultural Innovation Systems (AIS) concepts and perspectives and what they offer for understanding and supporting innovation systems, processes and networks. This has particular relevance for African agriculture as it faces several challenges, such as increasing and intensifying food production in a sustainable way and nourishing its fast-growing population, adapting to the consequences of climate change, and finding its rightful place in an increasingly global and complex international scene. Several initiatives and programmes seeking answers to these questions jointly organised a series of events during a Week on Agricultural Innovation in Africa (WAIA) held in Nairobi, Kenya, on 25–31 May 2013, of which the international workshop on Agricultural Innovation Systems in Africa (AISA) on 29–31 May was a major part. Another key event during this week, was the Eastern African Farmer Innovation Fair (EAFIF) held on 28–29 May, which was linked to AISA
3D Bio-printed Scaffold-free Nerve Constructs with Human Gingiva-derived Mesenchymal Stem Cells Promote Rat Facial Nerve Regeneration
Despite the promising neuro-regenerative capacities of stem cells, there is currently no licensed stem cell-based product in the repair and regeneration of peripheral nerve injuries. Here, we explored the potential use of human gingiva-derived mesenchymal stem cells (GMSCs) as the only cellular component in 3D bio-printed scaffold-free neural constructs that were transplantable to bridge facial nerve defects in rats. We showed that GMSCs have the propensity to aggregate into compact 3D-spheroids that could produce their own matrix. When cultured under either 2D- or 3D-collagen scaffolds, GMSC spheroids were found to be more capable of differentiating into both neuronal and Schwann-like cells than their adherent counterparts. Using a scaffold-free 3D bio-printer system, nerve constructs were printed from GMSC spheroids in the absence of exogenous scaffolds and allowed to mature in a bioreactor. In vivo transplantation of the GMSC-laden nerve constructs promoted regeneration and functional recovery when used to bridge segmental defects in rat facial nerves. Our findings suggest that GMSCs represent an easily accessible source of MSCs for 3D bio-printing of scaffold-free nervous tissue constructs with promising potential application for repair and regeneration of peripheral nerve defects. © 2018 The Author(s)
Global estimates for solutions to the linearized Monge--Amp\`ere equations
In this paper, we establish global estimates for solutions to the
linearized Monge-Amp\`ere equations under natural assumptions on the domain,
Monge-Amp\`ere measures and boundary data. Our estimates are affine invariant
analogues of the global estimates of Winter for fully nonlinear,
uniformly elliptic equations, and also linearized counterparts of Savin's
global estimates for the Monge-Amp\`ere equations.Comment: v2: presentation improve
FCNC Processes from D-brane Instantons
Low string scale models might be tested at the LHC directly by their Regge
resonances. For such models it is important to investigate the constraints of
Standard Model precision measurements on the string scale. It is shown that
highly suppressed FCNC processes like K0- bar K^0 oscillations or leptonic
decays of the D0-meson provide non-negligible lower bounds on both the
perturbatively and surprisingly also non-perturbatively induced string theory
couplings. We present both the D-brane instanton formalism to compute such
amplitudes and discuss various possible scenarios and their constraints on the
string scale for (softly broken) supersymmetric intersecting D-brane models.Comment: 28 pages, 13 figures, reference added, 1 typo corrected, style file
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