Transport properties of 2D graphene containing structural defects

We propose an extensive report on the simulation of electronic transport in 2D graphene in presence of structural defects. Amongst the large variety of such defects in sp$^2$ carbon-based materials, we focus on the Stone-Wales defect and on two divacancy-type reconstructed defects. First, based on ab initio calculations, a tight-binding model is derived to describe the electronic structure of these defects. Then, semiclassical transport properties including the elastic mean free paths, mobilities and conductivities are computed using an order-N real-space Kubo-Greenwood method. A plateau of minimum conductivity ($\sigma^{min}_{sc}= 4e^2/\pi h$) is progressively observed as the density of defects increases. This saturation of the decay of conductivity to $\sigma^{min}_{sc}$ is associated with defect-dependent resonant energies. Finally, localization phenomena are captured beyond the semiclassical regime. An Anderson transition is predicted with localization lengths of the order of tens of nanometers for defect densities around 1%.Comment: 17 pages, 17 figures, submitted to Phys. Rev.

Determinants of grassland primary production in seasonally-dry silvopastoral systems in Central America

Grassland primary productivity is the function that underpins the majority of the fodder production in cattle-rearing silvopastoral farms. Hence, understanding the factors that determine grassland productivity is critical for the design and management of silvpastoral systems. We studied the effect of two factors with documented impact on grassland productivity in seasonally dry silvopastures of Nicaragua, rainfall and trees. We assessed the effects of three species that differed in crown size and phenology, one evergreen, Cassia grandis, and two deciduous species, Guazuma ulmifolia and Tabebuia rosea. Overall, grassland ANPP had a quadratic response to rainfall, with a decline at high rainfall that coincided with peak standing biomass and grassland cover. Trees had a predominately negative effect on grassland productivity, and the effect was concentrated in the rainy season at peak productivity. The effect of the trees corresponded with the tree crown area, but not with crown density. Trees reduced the standing biomass of graminoids and increased forb biomass; thus, the effect of trees on grassland ANPP appears in part to respond to changes in grassland composition. We also found higher levels of soil moisture content below the tree canopy, particularly at the peak of the rainy season when soils tend to become waterlogged. The evergreen species, C. grandis, affected grassland ANPP more strongly than the deciduous specie

La contribution de la "squadra belga" au Concile Vatican II

En este artículo, basado en una exhaustiva investigación archivística, queremos presentar el papel de la llamada «squadra belga» en el Concilio Vaticano ii. Nuestra contribución muestra, claramente, que la Squadra Belga consistía en un grupo bastante pequeño de obispos y teólogos que se conocían muy bien entre ellos ya que habían estudiado juntos en Roma y residían en el Colegio Belga. Además, los obispos belgas nombraban a los profesores de teología de la Universidad Católica de Lovaina e intercambiaban impresiones con los teólogos de manera regular. En definitiva, existía una confianza mutua. Varios de estos teólogos eran apreciados internacionalmente por sus investigaciones y su compromiso con el ecumenismo, las ciencias bíblicas, patrísticas y afines. A diferencia de algunos teólogos franceses y alemanes, los profesores de Lovaina nunca habían sido objeto de condenas. Los belgas participaron activamente y tuvieron un papel importante en la elaboración de lo que llegarían a ser varios documentos conciliares: Lumen Gentium, Dei Verbum, Unitatis Redintegratio, Dignitatis Humanae y Gaudium et Spes, por mencionar solo los documentos en que su contribución es más visible

Cumulative effects of offshore renewables : From pragmatic policies to holistic marine spatial planning tools

Acknowledgement This work was supported by Supergen Offshore Renewable Energy (ORE) Hub, funded by the Engineering and Physical Sciences Research Council (EPSRC EP/S000747/1), the UK Department for Business, Energy & Industrial Strategy's (BEIS) offshore energy Strategic Environmental Assessment Programme, PELAgIO https://ecowind.uk/projects/pelagio/ funded by NERC (NE/X008835/1) and EcoNex https://ukerc.ac.uk/project/the-marine-energy-biodiversity-and-food-nexus-econex/ funded by UKERC.Peer reviewedPublisher PD

Panati and Webpanati - information systems for SNPS.

This paper describes two softwares: Panati and webPanati

A Stimulatory Role for Cytokinin in the Arbuscular Mycorrhizal Symbiosis of Pea

The arbuscular mycorrhizal (AM) symbiosis between terrestrial plants and AM fungi is regulated by plant hormones. For most of these, a role has been clearly assigned in this mutualistic interaction; however, there are still contradictory reports for cytokinin (CK). Here, pea plants, the wild type (WT) cv. Sparkle and its mutant E151 (Pssym15), were inoculated with the AM fungus Rhizophagus irregularis. E151 has previously been characterized as possessing high CK levels in non-mycorrhizal (myc-) roots and exhibiting high number of fungal structures in mycorrhizal (myc+) roots. Myc- and myc+ plants were treated 7, 9, and 11 days after inoculation (DAI) with synthetic compounds known to alter CK status. WT plants were treated with a synthetic CK [6-benzylaminopurine (BAP)] or the CK degradation inhibitor INCYDE, whereas E151 plants were treated with the CK receptor antagonist PI-55. At 13 DAI, plant CK content was analyzed by mass spectrometry. The effects of the synthetic compounds on AM colonization were assessed at 28 (WT) or 35 (E151) DAI via a modified magnified intersections method. The only noticeable difference seen between myc- and myc+ plants in terms of CK content was in the levels of nucleotides (NTs). Whereas WT plants responded to fungi by lowering their NT levels, E151 plants did not. Since NTs are thought to be converted into active CK forms, this result suggests that active CKs were synthesized more effectively in WT than in E151. In general, myc+ and myc- WT plants responded similarly to INCYDE by lowering significantly their NT levels and increasing slightly their active CK levels; these responses were less obvious in BAP-treated WT plants. In contrast, the response of E151 plants to PI-55 depended on the plant mycorrhizal status. Whereas treated myc- plants exhibited high NT and low active CK levels, treated myc+ plants displayed low levels of both NTs and active CKs. Moreover, treated WT plants were more colonized than treated E151 plants. We concluded that CKs have a stimulatory role in AM colonization because increased active CK levels were paralleled with increased AM colonization while decreased CK levels corresponded to reduced AM colonization

A new strategic framework to structure cumulative impact assessment (CIA)

Funding Information: This work was supported by Supergen Offshore Renewable Energy (ORE) Hub, funded by the Engineering and Physical Sciences Research Council (EPSRC EP/S000747/1) and the UK Department for Business, Energy & Industrial Strategy (BEIS) offshore energy Strategic Environmental Assessment Programme.Peer reviewedPostprin

A new strategic framework to structure Cumulative Impact Assessment (CIA)

Funding Information: This work was supported by Supergen Offshore Renewable Energy (ORE) Hub, funded by the Engineering and Physical Sciences Research Council (EPSRC EP/S000747/1) and the UK Department for Business, Energy & Industrial Strategy's (BEIS) offshore energy Strategic Environmental Assessment Programme. Publisher Copyright: © 2022, European Wave and Tidal Energy Conference. All rights reserved.Peer reviewedPublisher PD

Determinants of grassland primary production in seasonally-dry silvopastoral systems in Central America

Grassland primary productivity is the function that underpins the majority of the fodder production in cattle-rearing silvopastoral farms. Hence, understanding the factors that determine grassland productivity is critical for the design and management of silvpastoral systems. We studied the effect of two factors with documented impact on grassland productivity in seasonally dry silvopastures of Nicaragua, rainfall and trees. We assessed the effects of three species that differed in crown size and phenology, one evergreen, Cassia grandis, and two deciduous species, Guazuma ulmifolia and Tabebuia rosea. Overall, grassland ANPP had a quadratic response to rainfall, with a decline at high rainfall that coincided with peak standing biomass and grassland cover. Trees had a predominately negative effect on grassland productivity, and the effect was concentrated in the rainy season at peak productivity. The effect of the trees corresponded with the tree crown area, but not with crown density. Trees reduced the standing biomass of graminoids and increased forb biomass; thus, the effect of trees on grassland ANPP appears in part to respond to changes in grassland composition. We also found higher levels of soil moisture content below the tree canopy, particularly at the peak of the rainy season when soils tend to become waterlogged. The evergreen species, C. grandis, affected grassland ANPP more strongly than the deciduous species.This research has been co-funded by the Research Council of Norway, Environment 2015 Program and FRIMUF (Grants 204413 – SILPAS and 190134 – Multi-functional Landscapes) and by the European Commission, Directorate General for Research, within the 7th Framework Programme of RTD, Theme 2 – Biotechnology, Agriculture & Food (Grant Agreement No. 227265 - FUNCiTREE). P. Casals is supported by a Ramón y Cajal Contract (Ministerio de Economía y Competitividad, Spain)