Higher-Order Risk Preferences, Constant Relative Risk Aversion and the Optimal Portfolio Allocation

We derive the conditions for optimal portfolio choice within an expected utility framework considering alternative probability distributions that are able to capture the stylized features of asset returns at different degrees of accuracy. We show the importance of higher-order moments in the optimal decision on liquidity and relate them with the risk preference properties of riskiness, prudence and temperance

Flexible distribution functions, higher-order preferences and optimal portfolio allocation

In this paper we show that flexible probability distribution functions, in addition to been able to capture stylized facts of financial returns, can be used to identify pure higher-order effects of investors' optimizing behavior. We employ the five-parameter weighted generalized beta of the second kind distribution and other density functions nested within it to determine the conditions under which risk averse, prudent and temperate agents are diversifiers in the standard portfolio choice theory. Within this framework, we illustrate through comparative statics the economic significance of higher-order moments in return's distributions

The race to securitize the Arctic in a post-Cold War scenario

The Arctic implies a planetary struggle to stop the rapid change of its ecosystem caused by global climate change, with the global impact it could generate in the future. as a consequence of this first ecological challenge, the Arctic scenario is becoming more interesting for key transnational actors to develop new business opportunities related to mining exploitation, energy reserves and logistics services, where the result will tend to prioritize business and safety on the ecology, reaffirming the meta-tragedy in the arctic region. Due to the complexity of the Arctic scenario, the preference for intergovernmental forums and the ambiguous interests and roles of its actors, the inadequate trinomial between a global ecological tragedy, an individual economic business and a collective security career will tend to subsist and increase its tragic effects about the environmentEl Ártico implica una lucha planetaria para detener el rápido cambio de su ecosistema causado por el cambio climático global, con el impacto global que podría generar en el futuro. Como consecuencia de este primer desafío ecológico, el escenario del Ártico se está volviendo más interesante para los actores transnacionales clave para desarrollar nuevas oportunidades de negocios relacionadas con la explotación minera, las reservas de energía y los servicios logísticos, donde el resultado tenderá a priorizar los negocios y la seguridad sobre la ecología, reafirmando la meta- tragedia en la región del Ártico. debido a la complejidad del escenario Ártico, la preferencia por foros intergubernamentales y los intereses y roles ambiguos de sus actores, el trinomio inadecuado entre una tragedia ecológica global, un negocio económico individual y una carrera de seguridad colectiva tenderán a subsistir e incrementar sus efectos trágicos sobre el medio ambient

2D chiral structures in quinoline mixed Langmuir monolayers.

Chirality at interfaces is a relevant topic in nanoscience, as well as a key point for prebiotic chemistry. Mixed Langmuir monolayers, composed of the anionic phospholipid dimyristoyl phosphatidic acid (DMPA) and the cationic amphiphilic quinoline derivative 2-methyl-1-octadecylquinoline (MQ) have been built at the air-water interface. Both DMPA and MQ molecules are miscible, thus the equimolar mixture yields homogeneous monolayers completely. Chiral domains have been formed by this monolayer and observed in situ by Brewster angle microscopy (BAM). These chiral domains display a large array of shapes and sizes. The chirality of the monolayers has been confirmed by circular dichroism spectroscopy. The ordered aggregation of the quinoline group into large chiral supramolecular structures is proposed as the molecular origin of the observed chirality. Theoretical simulations using molecular mechanics confirm the strong trend of the quinoline group to form chiral aggregates. The great diversity in the size and shape of the chiral domains has been found to be strongly influenced by the competition between two nuclei growth mechanisms. An experimental procedure allowing a minimized growth through one of these mechanism is proposed, achieving a homogeneous distribution of ring-shaped domains. An overshoot in the pi-A isotherms of this mixed monolayer appears at an intermediate surface pressure. This overshoot is interpreted as being due to the large difference between the surface pressure which starts the nuclei formation, pi(crit) and the superficial pressure in which the nuclei can grow, pi(e). The rather small pi(e) value compared to pi(crit) observed for this system must be attributed to the molecular interactions involved in the mixed monolayer, which facilitate the incorporation of molecules in preformed nuclei

DNA methylation at the Igf2/H19 imprinting control region is associated with cerebellum mass in outbred mice

Background: Insulin-like growth factor 2 (Igf2) is a paternally expressed imprinted gene regulating fetal growth, playing an integral role in the development of many tissues including the brain. The parent-of-origin specific expression of Igf2 is largely controlled by allele-specific DNA methylation at CTCF-binding sites in the imprinting control region (ICR), located immediately upstream of the neighboring H19 gene. Previously we reported evidence of a negative correlation between DNA methylation in this region and cerebellum weight in humans. Results: We quantified cerebellar DNA methylation across all four CTCF binding sites spanning the murine Igf2/H19 ICR in an outbred population of Heterogeneous Stock (HS) mice (n = 48). We observe that DNA methylation at the second and third CTCF binding sites in the Igf2/H19 ICR shows a negative relationship with cerebellar mass, reflecting the association observed in human post-mortem cerebellum tissue. Conclusions: Given the important role of the cerebellum in motor control and cognition, and the link between structural cerebellar abnormalities and neuropsychiatric phenotypes, the identification of epigenetic factors associated with cerebellum growth and development may provide important insights about the etiology of psychiatric disorders

Increased Comfort of Polyester Fabrics

[EN] The hydrophilicity of fibers is directly related to the comfort of a fabric and represents one of the most important aspects of a textile. Therefore, polyester (PES) modification has focused on an increase in moisture content and a subsequent improvement of the user's experience. Based on the glycerol hygroscopic properties, the main objective has been the enhancement of the hydrophilicity of polyester by glycerol treatments. Furthermore, microwave irradiation and alkaline treatment have been applied, in order to increase glycerol adhesion. Treated PES samples were characterized by performing moisture content, negative ion, water diffusion and water vapor resistance analyses. The effect of different treatment conditions such as bath ratio (1/10 or 1/15), temperature (40, 60 or 100 degrees C), time (2 or 5 min) and microwave radiation intensity (300 or 500 W) was evaluated. The moisture content of treated PES results indicated that by decreasing the bath ratio and increasing the time and temperature the moisture gain can reach almost 14%, which can be easily related to increases in the weight of the fiber. The treatment with alkali was done and led to the highest moisture increase. Treatment with 500 W microwave irradiation led to higher glycerol retention after rinsing. Different experimental conditions were applied to the glycerol-treated PES fabrics, and a clear improvement in moisture content was obtained increasing the comfort. The results were compared with the ones obtained for cotton and wool, where the moisture is higher than non treated PES.The authors wish to thank the Ministerio de Ciencia, Innovacion y Universidades (RTI2018-094014-B-100 Project), for financial support.Martí, M.; Gisbert Paya, J.; Bonet-Aracil, M.; Jovancic, P.; Lis, MJ.; Coderch, L. (2021). Increased Comfort of Polyester Fabrics. Polymers. 13(17):1-12. https://doi.org/10.3390/polym13173010S112131

Influence of glyoxal in the physical characterization of PVA nanofibres

[EN] The influence of solution composition is directly related to the properties of polyvinyl alcohol (PVA) nanofibers. Electrospinning is a viable technique to develop PVA nanofibers. The presence of a crosslinking agent such as glyoxal can produce variations not only in anti-water solubility effect, but also in the morphology of the electrodeposited fibers. The objective of this study was to characterize the influence of glyoxal on PVA nanofibers. Thus, we studied fiber dimensions, the weight of deposited fibers, and fiber crystallinity. The relation between those properties and the properties of the nanofiber web (color, opacity, and roughness) were studied. In this study we changed glyoxal concentration. Scanning electron microscopy, differential scanning calorimetry, and atomic force microscopy showed changes in the fiber properties. We could observe how the diameter fiber increased, the collector surface was widely covered, and the fiber crystallinity decreased. Regarding the properties of the web, the roughness decreased and the color turned whiter.The authors wish to acknowledge the financial support of the MINISTERIO DE CIENCIA E INNOVACION. Ref: CIT-020000-2008-016 for financial support. Also, the microscopy services at UPV are gratefully acknowledged for their assistance in using AFM techniques, and Octavio Fenollar at UPV is gratefully acknowledged for his assistance in using calorimetric techniques.Blanes, M.; Gisbert, MJ.; Marco, B.; Bonet Aracil, MA.; Gisbert Paya, J.; Balart Gimeno, RA. (2010). Influence of glyoxal in the physical characterization of PVA nanofibres. Textile Research Journal. 80(14):1465-1472. doi:10.1177/0040517509357654S14651472801

Evaluation of the long-term compressive strength development of the sewage sludge ash/metakaolin-based geopolymer

[EN] This paper aimed to evaluate the long-term compressive strength development of the sewage sludge ash/metakaolin (SSA/MK)¿based geopolymer. SSA/MK¿based geopolymeric mortars and pastes were produced at 25ºC with different SSA contents (0 - 30 wt.%). Compressive strength tests were run within the 3-720 curing days range. A physicochemical characterisation (X-ray diffraction and scanning electron microscopy) was performed in geopolymeric pastes. All the geopolymeric mortars presented a compressive strength gain with curing time. The mortars with all the SSA evaluated contents (10, 20, 30 wt.%) developed a compressive strength over 40 MPa after 720 curing days at 25ºC. The maximum compressive strength of the mortars with SSA was approximately 61 MPa (10 wt.% of SSA), similarly to the reference mortar (100% MK-based geopolymer). The microstructure analyses showed that the SSA/MK¿based geopolymer presented a dense microstructure with N-A-S-H gel formation.This study was financed partly by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Su-perior -Brasil (CAPES) -(Finance Code 001 and CAPES/DGU n. 266/12), and the National Council of Scientific and Technological Development -Bra-sil (CNPq) -(n. 14/2013, process 478057/2013-0 and 309015/2015-4). The authors would like to thank Programa Institucional de Internacionalizacao - CAPES -PrInt. The authors acknowledge the Scanning Electron Microscopy Service of FEIS/UN-ESP, Servico Municipal Autonomo de Agua e Es-goto (SEMAE) from the Sao Jose do Rio Preto city -SP, Brazil and Diatom Mineracao Ltda. The authors would like to thank Programa Institucional de Internacionalizacao CAPES -PrInt.Istuque, D.; Soriano Martinez, L.; Borrachero Rosado, MV.; Paya Bernabeu, JJ.; Akasaki, JL.; Melges, JLP.; Tashima, MM. (2021). Evaluation of the long-term compressive strength development of the sewage sludge ash/metakaolin-based geopolymer. Materiales de Construcción. 71(343):1-10. https://doi.org/10.3989/mc.2021.13220S1107134