419 research outputs found
A best choice among asset pricing models? The conditional CAPM in Australia.
We use Australian data to test the Conditional CAPM (Jagannathan and Wang, 1996). Our results are generally supportive: the model performs well compared with a number of competing asset pricing models. In contrast to Jagannathan and Wang’s study, however, we find that the inclusion of the market for human capital does not ‘save’ the concept of the time-independent market beta (it remains insignificant). We find support for the role of a “small-minus-big” factor (Fama and French, 1993) in pricing the cross-section of returns and find grounds to disagree with Jagannathan and Wang’s argument that this factor proxies for misspecified market risk
¿Influyen las mujeres directivas en el coste de la financiación bancaria? La experiencia de Australia
We investigate the effect of women directors on the cost of bank loans for a sample of Australian listed firms during the period 2002-2017. More women on both boards and committees are associated with lower loan spreads, reduced default risk, and improved financial reporting quality. The reduction in loan spread is seen from when the first female director joins the board, and the effect of that is stronger than the effects of additional (second and subsequent) women joining the board. Moreover, womens leadership status reinforces this effect. Our results are consistent with the idea that female directors exhibit greater risk aversion than male directors, that women are not treated as tokens and are influential even as a minority group on the board and that they enhance corporate governance and reporting quality.Investigamos el efecto de las mujeres consejeras en el coste de los préstamos bancarios para una muestra de empresas australianas que cotizan en bolsa durante el período 2002-2017. Un mayor número de mujeres tanto en los consejos de administración como en los comités se asocia con menores diferenciales de los préstamos, un menor riesgo de impago y una mejor calidad de los informes financieros. La reducción del diferencial de los préstamos se observa desde la primera mujer consejera, y resulta más intensa que los efectos asociados a las siguientes (segunda y siguientes) mujeres incorporadas al consejo. Además, el estatus de liderazgo de la mujer refuerza este efecto. Nuestros resultados son coherentes con las nociones de que las mujeres consejeras muestran una mayor aversión al riesgo que los hombres consejeros, que las mujeres no son tratadas como símbolo siendo influyentes incluso como grupo minoritario en el consejo y que mejoran el gobierno corporativo y la calidad de la información
Bias and consistency of the maximum Sharpe ratio
We show that the maximum Sharpe ratio obtained via the Markowitz optimization procedure from a sample of returns on a number of risky assets is, under commonly satisfied assumptions, biased upwards for the population value. Thus investment advice, decisions and assessments based on the estimated Sharpe ratio will be overly optimistic. The bias in the estimator is shown theoretically and illustrated using a data set of Spiders and iShares. We obtain bounds on the difference between the sample maximum Sharpe ratio and its population counterpart and show that the sample estimator is consistent for the population value; thus the bias disappears asymptotically, under some reasonable assumptions. However, the bias can be significant in finite samples and persist even in very large samples. We demonstrate this with simulations based on portfolios formed from normally and t–distributed returns. As expected, the over-optimistic risk-return tradeoff predicted by the procedure is not reflected in corresponding good out-of-sample portfolio performance of the Spiders and iShares
IVOA Recommendation: VOTable Format Definition Version 1.3
This document describes the structures making up the VOTable standard. The
main part of this document describes the adopted part of the VOTable standard;
it is followed by appendices presenting extensions which have been proposed
and/or discussed, but which are not part of the standard
Adaptation to multi-meter sea-level rise should start now
Sea-level rise will fundamentally change coastal zones worldwide (Cooley et al 2022). A global two meters rise of sea level will be exceeded sooner or later within a time window ranging from one century to as long as two millennia, depending on future greenhouse gas emissions and polar ice-sheet melting (Fox-Kemper et al 2021). Here, we show that in addition to climate mitigation to slow this rise, adaptation to two meters of sea-level rise should start now. This involves changing our mindset to define a strategic vision for these threatened coastal areas and identify realistic pathways to achieve this vision. This can reduce damages, losses, and lock-ins in the future, identify problems before they become critical and exploit opportunities if they emerge. To meet this challenge, it is essential that coastal adaptation becomes core to coastal development, especially for long-lived critical infrastructure. Coastal adaptation will be an ongoing process for many decades and centuries, requiring the support of climate services, which make the links between science, policy and adaptation practice
Isotopic control of the boron-vacancy spin defect in hexagonal boron nitride
We report on electron spin resonance (ESR) spectroscopy of boron-vacancy
(V) centers hosted in isotopically-engineered hexagonal boron
nitride (hBN) crystals. We first show that isotopic purification of hBN with
N yields a simplified and well-resolved hyperfine structure of
V centers, while purification with B leads to narrower ESR
linewidths. These results establish isotopically-purified hBN
crystals as the optimal host material for future use of V spin
defects in quantum technologies. Capitalizing on these findings, we then
demonstrate optically-induced polarization of N nuclei in
hBN, whose mechanism relies on electron-nuclear spin mixing in
the V ground state. This work opens up new prospects for future
developments of spin-based quantum sensors and simulators on a two-dimensional
material platform.Comment: 6 pages, 3 figur
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Drought and the Sacramento-San Joaquin Delta, 2012–2016: Environmental Review and Lessons
This paper reviews environmental management and the use of science in the Sacramento–San Joaquin Delta during California’s 2012–2016 drought. The review is based on available reports and data, and guided by discussions with 27 agency staff, stake-holders, and researchers. Key management actions for the drought are discussed relative to four major drought water management priorities stated by water managers: support public health and safety, control saltwater intrusion, preserve cold water in Shasta Reservoir, and maintain minimum protections for endangered species. Despite some success in streamlining communication through interagency task forces, conflicting management mandates sometimes led to confusion about priorities and actions during the drought (i.e., water delivery, the environment, etc.). This report highlights several lessons and offers suggestions to improve management for future droughts. Recommendations include use of pre-drought warnings, timely drought declarations, improved transparency and useful documentation, better scientific preparation, development of a Delta drought management plan (including preparing for salinity barriers), and improved water accounting. Finally, better environmental outcomes occur when resources are applied to improving habitat and bolstering populations of native species during inter-drought periods, well before stressful conditions occur.
Update on LIPID MAPS classification, nomenclature, and shorthand notation for MS-derived lipid structures
A comprehensive and standardized system to report lipid structures analyzed by mass spectrometry is essentialfor the communication and storage of lipidomics data. Herein, an update on both the LIPID MAPSclassification system and shorthand notation of lipid structures is presented for lipid categories Fatty Acyls(FA), Glycerolipids (GL), Glycerophospholipids (GP), Sphingolipids (SP), and Sterols (ST). With its majorchanges, i.e. annotation of ring double bond equivalents and number of oxygens, the updated shorthandnotation facilitates reporting of newly delineated oxygenated lipid species as well. For standardized reportingin lipidomics, the hierarchical architecture of shorthand notation reflects the diverse structural resolutionpowers provided by mass spectrometric assays. Moreover, shorthand notation is expanded beyond mammalianphyla to lipids from plant and yeast phyla. Finally, annotation of atoms is included for the use of stableisotope-labelled compounds in metabolic labelling experiments or as internal standards
3D color homography model for photo-realistic color transfer re-coding
Color transfer is an image editing process that naturally transfers the color theme of a source image to a target image. In this paper, we propose a 3D color homography model which approximates photo-realistic color transfer algorithm as a combination of a 3D perspective transform and a mean intensity mapping. A key advantage of our approach is that the re-coded color transfer algorithm is simple and accurate. Our evaluation demonstrates that our 3D color homography model delivers leading color transfer re-coding performance. In addition, we also show that our 3D color homography model can be applied to color transfer artifact fixing, complex color transfer acceleration, and color-robust image stitching
Sea-level rise: from global perspectives to local services
Coastal areas are highly diverse, ecologically rich, regions of key socio-economic activity, and are particularly sensitive to sea-level change. Over most of the 20th century, global mean sea level has risen mainly due to warming and subsequent expansion of the upper ocean layers as well as the melting of glaciers and ice caps. Over the last three decades, increased mass loss of the Greenland and Antarctic ice sheets has also started to contribute significantly to contemporary sea-level rise. The future mass loss of the two ice sheets, which combined represent a sea-level rise potential of ∼65 m, constitutes the main source of uncertainty in long-term (centennial to millennial) sea-level rise projections. Improved knowledge of the magnitude and rate of future sea-level change is therefore of utmost importance. Moreover, sea level does not change uniformly across the globe and can differ greatly at both regional and local scales. The most appropriate and feasible sea level mitigation and adaptation measures in coastal regions strongly depend on local land use and associated risk aversion. Here, we advocate that addressing the problem of future sea-level rise and its impacts requires (i) bringing together a transdisciplinary scientific community, from climate and cryospheric scientists to coastal impact specialists, and (ii) interacting closely and iteratively with users and local stakeholders to co-design and co-build coastal climate services, including addressing the high-end risks
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