3,928 research outputs found
The performance of socially responsible mutual funds: the role of fees and management companies
In this paper, we shed light on the debate about the financial performance of socially responsible
investment (SRI) mutual funds by separately analyzing the contributions of before-fee performance and
fees to SRI funds' performance and by investigating the role played by fund management companies in
the determination of those variables. We apply the matching estimator methodology to obtain our results
and find that in the period 1997-2005, US SRI funds had significantly higher fees and better before- and
after-fee performance than conventional funds with similar characteristics. Differences, however, were
driven exclusively by SRI funds run by management companies specialized in socially responsible
investment
Dynamical magnetic anisotropy and quantum phase transitions in a vibrating spin-1 molecular junction
We study the electronic transport through a spin-1 molecule in which
mechanical stretching produces a magnetic anisotropy. In this type of device, a
vibron mode along the stretching axis will couple naturally to the molecular
spin. We consider a single molecular vibrational mode and find that the
electron-vibron interaction induces an effective correction to the magnetic
anisotropy that shifts the ground state of the device toward a non-Fermi liquid
phase. A transition into a Fermi liquid phase could then be achieved, by means
of mechanical stretching, passing through an underscreened spin-1 Kondo regime.
We present numerical renormalization group results for the differential
conductance, the spectral density, and the magnetic susceptibility across the
transition.Comment: 7 pages, 7 figure
War and Economics: Spanish Civil War Finances Revisited
This paper reviews how the Spanish civil war was financed. We present new evidence to show that the two combatant parties, the Republican government and the Franco administration followed similar financial strategies. In both cases money creation, rather than new taxes or the issue of debt, was the main mechanism used to cover the expenses of the war. We argue, contrary to the established knowledge, that both sides consumed a similar amount of domestic and foreign resources. We also argue that the Spanish Republic did not lose the war because of a lack of means. International factors, such as the Non-Intervention agreement promoted by France and Great Britain, and the military setbacks of the Republican army during the first year of the war, were decisive for Franco’s victory in 1939.Spain, civil war, financial resources
The performance of socially responsible mutual funds: the role of fees and management companies
In this paper, we shed light on the debate about the financial performance of socially responsible investment (SRI) mutual funds by separately analyzing the contributions of before-fee performance and fees to SRI funds' performance and by investigating the role played by fund management companies in the determination of those variables. We apply the matching estimator methodology to obtain our results and find that in the period 1997-2005, US SRI funds had significantly higher fees and better before- and after-fee performance than conventional funds with similar characteristics. Differences, however, were driven exclusively by SRI funds run by management companies specialized in socially responsible investment.Socially responsible investment, Mutual fund fees, Mutual fund performance, Matching estimators
Shift factor-based SCOPF topology control MIP formulations with substation configurations
Topology control (TC) is an effective tool for managing congestion, contingency events, and overload control. The majority of TC research has focused on line and transformer switching. Substation reconfiguration is an additional TC action, which consists of opening or closing breakers not in series with lines or transformers. Some reconfiguration actions can be simpler to implement than branch opening, seen as a less invasive action. This paper introduces two formulations that incorporate substation reconfiguration with branch opening in a unified TC framework. The first method starts from a topology with all candidate breakers open, and breaker closing is emulated and optimized using virtual transactions. The second method takes the opposite approach, starting from a fully closed topology and optimizing breaker openings. We provide a theoretical framework for both methods and formulate security-constrained shift factor MIP TC formulations that incorporate both breaker and branch switching. By maintaining the shift factor formulation, we take advantage of its compactness, especially in the context of contingency constraints, and by focusing on reconfiguring substations, we hope to provide system operators additional flexibility in their TC decision processes. Simulation results on a subarea of PJM illustrate the application of the two formulations to realistic systems.The work was supported in part by the Advanced Research Projects Agency-Energy, U.S. Department of Energy, under Grant DE-AR0000223 and in part by the U.S. National Science Foundation Emerging Frontiers in Research and Innovation under Grant 1038230. Paper no. TPWRS-01497-2015. (DE-AR0000223 - Advanced Research Projects Agency-Energy, U.S. Department of Energy; 1038230 - U.S. National Science Foundation Emerging Frontiers in Research and Innovation)http://buprimo.hosted.exlibrisgroup.com/primo_library/libweb/action/openurl?date=2017&issue=2&isSerivcesPage=true&spage=1179&dscnt=2&url_ctx_fmt=null&vid=BU&volume=32&institution=bosu&issn=0885-8950&id=doi:10.1109/TPWRS.2016.2574324&dstmp=1522778516872&fromLogin=truePublished versio
Influence of stretching on warm up in jump and speed
El objetivo del estudio es determinar si la realización de estiramientos pasivos, incluidos como parte del calentamiento, influyen en el rendimiento de la fuerza explosiva, en este caso en varios tests de salto vertical: Squat Jump (SJ), Countermouvement Jump (CMJ) y Reactive Jump (RJ); y también en un test de velocidad de 30 metros (mts.) con salida lanzada de 5 mts.
Para ello, 9 jugadores del Málaga Club de Fútbol de categoría juvenil (18,22 ± 0,441 años) realizaron 2 protocolos de calentamiento en dos semanas consecutivas en su día de recuperación. Los jugadores de fútbol utilizan los estiramientos pasivos en su calentamiento y el tipo de esfuerzo al que se someten durante su actividad tiene un alto componente de fuerza explosiva de tipo balístico, movimientos que se ejecutan con gran intensidad y corta duración, tales como golpear el balón, sprints, cambios de dirección, saltos, etc.
Se han encontrado disminuciones en el rendimiento de los test de SJ y RJ, así como también en el test de velocidad, obteniéndose valores significativos (p<0,05) tanto para la potencia y el tiempo de vuelo del test RJ, como también para el test de velocidad. En cuanto al test CMJ, se han obtenido beneficios aunque las diferencias no han sido significativas. Por tanto, la realización de estiramientos pasivos influye de forma negativa en el rendimiento de la fuerza explosiva y la velocidad en una muestra de futbolistas entrenados
The 2008 Terrestrial Vegetation of Biscayne National Park FL, USA Derived From Aerial Photography, NDVI, and LiDAR
Established as a National Park in 1980, Biscayne National Park (BISC) comprises an area of nearly 700 km2 , of which most is under water. The terrestrial portions of BISC include a coastal strip on the south Florida mainland and a set of Key Largo limestone barrier islands which parallel the mainland several kilometers offshore and define the eastern rim of Biscayne Bay. The upland vegetation component of BISC is embedded within an extensive coastal wetland network, including an archipelago of 42 mangrove-dominated islands with extensive areas of tropical hardwood forests or hammocks. Several databases and vegetation maps describe these terrestrial communities. However, these sources are, for the most part, outdated, incomplete, incompatible, or/and inaccurate. For example, the current, Welch et al. (1999), vegetation map of BISC is nearly 10 years old and represents the conditions of Biscayne National Park shortly after Hurricane Andrew (August 24, 1992). As a result, a new terrestrial vegetation map was commissioned by The National Park Service Inventory and Monitoring Program South Florida / Caribbean Network
Noise in Grover's Quantum Search Algorithm
Grover's quantum algorithm improves any classical search algorithm. We show
how random Gaussian noise at each step of the algorithm can be modelled easily
because of the exact recursion formulas available for computing the quantum
amplitude in Grover's algorithm. We study the algorithm's intrinsic robustness
when no quantum correction codes are used, and evaluate how much noise the
algorithm can bear with, in terms of the size of the phone book and a desired
probability of finding the correct result. The algorithm loses efficiency when
noise is added, but does not slow down. We also study the maximal noise under
which the iterated quantum algorithm is just as slow as the classical
algorithm. In all cases, the width of the allowed noise scales with the size of
the phone book as N^-2/3.Comment: 17 pages, 2 eps figures. Revised version. To be published in PRA,
December 199
Anatomical Retinal Changes after Photodynamic Therapy in Chronic Central Serous Chorioretinopathy
Purpose. To evaluate anatomical retinal changes measured by spectral-domain optical coherence tomography (SD-OCT), after applying photodynamic therapy (PDT) for treatment of chronic central serous chorioretinopathy (CSC).
Methods. A retrospective analysis was conducted on 43 patients (48 eyes) with chronic CSC treated with PDT. Visual acuity (VA), central retinal thickness (CRT), outer nuclear layer (ONL) thickness, subretinal fluid (SRF), and photoreceptor ellipsoid zone (EZ) measured by SD-OCT were collected at baseline and at 3, 6, and 12 months after PDT. Differences between normally distributed variables were calculated by a paired-sample t-test; p < 0 05 was considered statistically significant.
Results. Mean age was 50 +/- 9.8 years. Mean time from diagnosis to PDT was 12.5 months. Baseline VA was 0.51 +/- 0.24 and significantly improved (p < 0 001) to 0.74 +/- 0.26 one year after PDT. CRT and SRF significantly decreased (p < 0 001) at 3, 6, and 12 months after treatment. ONL thickness and EZ did not significantly change at any point during follow-up.
Conclusions. Not significant changes were found in the ONL or EZ 12 months after PDT
An experimental analysis od the stability and the dynamics of asixymmetric liquid bridges between unequal disks
In this paper experimental results related to both stability
an the dynamic of a asiximmetric liquid bridge between unequal disk are presented. Experiments have been performed by using a drop tower facility and the response of the liquid bridge to a sudden change of the acceleration level acting on it has bee obtained
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