Dirac fermion time-Floquet crystal: manipulating Dirac points

We demonstrate how to control the spectra and current flow of Dirac electrons in both a graphene sheet and a topological insulator by applying either two linearly polarized laser fields with frequencies $\omega$ and $2\omega$ or a monochromatic (one-frequency) laser field together with a spatially periodic static potential(graphene/TI superlattice). Using the Floquet theory and the resonance approximation, we show that a Dirac point in the electron spectrum can be split into several Dirac points whose relative location in momentum space can be efficiently manipulated by changing the characteristics of the laser fields. In addition, the laser-field controlled Dirac fermion band structure -- Dirac fermion time-Floquet crystal -- allows the manipulation of the electron currents in graphene and topological insulators. Furthermore, the generation of dc currents of desirable intensity in a chosen direction occurs when applying the bi-harmonic laser field which can provide a straightforward experimental test of the predicted phenomena.Comment: 9 pages, 7 figures, version that will appear in Phys. Rev.

Sustainability in the boardroom: An empirical examination of Dow Jones sustainability world index leaders

In recent years, there has been a virtual explosion of interest in corporate governance. Corporate scandals and the need to protect minority shareholders' interests, for example, are some of the reasons behind the development of corporate governance codes in numerous countries and corporations. At the same time, the concepts of "sustainable development", "corporate responsibility", and "corporate citizenship" have taken root in the business world. Although an extensive body of research treats the fields of corporate governance and sustainable development separately, less attention has been paid to the interaction between both fields. This paper attempts to bridge this gap by examining how corporate governance systems are evolving in order to integrate sustainable development thinking into them. We do so by analyzing the governance systems of the 18 corporations that are leading the market sectors considered by the Dow Jones Sustainability World Index (DJSWI). We present the results of our in depth analysis of the 18 cases and propose the Sustainable Corporate Governance Model that emerges from that analysis.Corporate governance; sustainable corporate governance; sustainable enterprise; sustainable development; business in society;

Description of the ICCAT length at age data base for bluefin tuna from the eastern Atlantic, including the Mediterranean Sea

This study aims to describe the current length at age database available for Eastern Atlantic bluefin tuna management area. A total of 8 500 spines and 5 000 otoliths were read from specimens caught from 1984 to 2017 in both the Atlantic Ocean and Mediterranean Sea. Obtaining ALKs for this species is difficult, as it has a wide length range and spatial distribution, and sampling is costly. Unfortunately, there are practically no contributions to this database from the East Atlantic and Mediterranean Sea countries, and only thanks to the initiative of the GBYP has it been possible to increase the number of samples in the ICCAT database in the last 10 years. As a result, the current ICCAT length at age database has incomplete spatial, temporal and size range coverage. However, it may be suitable as conditional age-at-length data for the Stock Synthesis model

Insulin and GLP-1 infusions demonstrate the onset of adipose-specific insulin resistance in a large fasting mammal: potential glucogenic role for GLP-1.

Prolonged food deprivation increases lipid oxidation and utilization, which may contribute to the onset of the insulin resistance associated with fasting. Because insulin resistance promotes the preservation of glucose and oxidation of fat, it has been suggested to be an adaptive response to food deprivation. However, fasting mammals exhibit hypoinsulinemia, suggesting that the insulin resistance-like conditions they experience may actually result from reduced pancreatic sensitivity to glucose/capacity to secrete insulin. To determine whether fasting results in insulin resistance or in pancreatic dysfunction, we infused early- and late-fasted seals (naturally adapted to prolonged fasting) with insulin (0.065 U/kg), and a separate group of late-fasted seals with low (10 pM/kg) or high (100 pM/kg) dosages of glucagon-like peptide-1 (GLP-1) immediately following a glucose bolus (0.5g/kg), and measured the systemic and cellular responses. Because GLP-1 facilitates glucose-stimulated insulin secretion, these infusions provide a method to assess pancreatic insulin-secreting capacity. Insulin infusions increased the phosphorylation of insulin receptor and Akt in adipose and muscle of early and late fasted seals; however the timing of the signaling response was blunted in adipose of late fasted seals. Despite the dose-dependent increases in insulin and increased glucose clearance (high dose), both GLP-1 dosages produced increases in plasma cortisol and glucagon, which may have contributed to the glucogenic role of GLP-1. Results suggest that fasting induces adipose-specific insulin resistance in elephant seal pups, while maintaining skeletal muscle insulin sensitivity, and therefore suggests that the onset of insulin resistance in fasting mammals is an evolved response to cope with prolonged food deprivation

Standardized age - Length key for east Atlantic and Mediterranean bluefin tuna based on otoliths readings.

This paper presents an age-length key (ALK) based on age estimates from otoliths following a recent standardized reading criterion. Sampling of Atlantic bluefin tuna (Thunnus thynnus) otoliths comes from the “Biological and genetic sampling and analysis" (GBYP) project and was complemented with some samples from the Spanish institute of Oceanography. Using 2010 to 2012 data improves length range and monthly sampling coverage. Variability in length at age from ALK seems acceptable and although it was developed from data pooled over three years, the bias is likely to be small. Final age was adjusted to account for the date of capture and the timing of bands formation throughout the year. Monthly formation of edge type, translucent or opaque, was inconclusive and did not allow establishing an annual formation pattern. The confidence interval of the von Bertalanffy growth model curve fitted to ALK data included currently adopted growth function for eastern bluefin stock and western stock function up to age 8. From age 9, this last western function predicts slightly older ages than the present ALK growth model.Postprint0,000

Age-length keys availability for Atlantic bluefin tuna captured in the eastern management area

This paper analyzes the available direct ageing information in the last decade from Atlantic bluefin tuna caught in the eastern management area. To investigate differences among ALKs, a standard Von Bertalanffy growth function (VB) was fit to length at age data for each stratum. A deficient convergence of VB fitting to the asymptotic length due to the scarcity of old specimens was found for all available ALKs. After these analyses some records were identified as outliers (reading methodological issues) and removed from the data base.En prensa0,000

Cysteine-proteases and cystatins from barley: molecular and functional characterization in housekeeping and defense processes

Plant cysteine-proteases (CysProt) represent a well-characterized type of proteolytic enzymes that fulfill tightly regulated physiological functions (senescence and seed germination among others) and defense roles. This article is focused on the group of papain-proteases C1A (family C1, clan CA) and their inhibitors, phytocystatins (PhyCys). In particular, the protease–inhibitor interaction and their mutual participation in specific pathways throughout the plant's life are reviewed. C1A CysProt and PhyCys have been molecularly characterized, and comparative sequence analyses have identified consensus functional motifs. A correlation can be established between the number of identified CysProt and PhyCys in angiosperms. Thus, evolutionary forces may have determined a control role of cystatins on both endogenous and pest-exogenous proteases in these species. Tagging the proteases and inhibitors with fluorescence proteins revealed common patterns of subcellular localization in the endoplasmic reticulum–Golgi network in transiently transformed onion epidermal cells. Further in vivo interactions were demonstrated by bimolecular fluorescent complementation, suggesting their participation in the same physiological processes

Current Status of the Insecticide Resistance in Aedes aegypti (Diptera: Culicidae) from Mexico

The mosquito Aedes aegypti (Diptera: Culicidae) is the primary vector of dengue in Mexico and lately virus Chikungunya, although Aedes albopictus is widely distributed; its role in both diseases’ transmission has not been confirmed. The control of mosquitoes in Mexico includes source reduction consisting in the elimination of containers that are favorable sites for oviposition and development of the aquatic stage. The use of insecticides is to control larvae and adulticides as outdoor ultra-low volume applications and indoor residual spray and more recently impregnated materials. The health department regulates the use of insecticides, and such regulations are revised and adapted over time. Since 1999, the vector control regulations gave preference to the use of pyrethroids, a permethrin-based formulation to control adult forms. This insecticide was used as the only adulticide in Mexico for more than 10 years. The consequences of this actions have evolved in a widespread and strong resistance to other insecticides, mainly pyrethroids. We include in this revision evidence of resistance reported in Ae. aegypti in Mexico