Identification of Differential Agronomic Traits in Early Stage Teosinte, Flint, Dent, and Sugar (Sweet) Corn Varieties in Competition with Weeds

Weed competition reduces corn yield. Today’s corn monoculture relies heavily on herbicide inputs to maintain yield. However, teosinte, corn’s ancestor, was successfully grown in mixed production systems. Harnessing genes and traits that allow teosinte to be a better competitor but which may have been lost during corn domestication could help producers reduce herbicide inputs and maintain yield. The first step to finding those genes is to identify varieties of corn and lines of teosinte that have a higher tolerance of weeds or greater weed suppressive ability. Five introductions of teosinte and 14 varieties of corn (including dent, heritage, and sweet corn types) were cultivated with and without weed pressure. Early and end of season growth characteristics including leaf area, plant height, stem diameter, biomass, and yield, when possible, indicated a wide range of weed tolerance. Differences between weedy and weed-free treatments within a type ranged from 1-10% in corn height, 3-20% in leaf area, 1-27% in corn biomass (July), 0.4-28% in top collar height (September), and 2-17% in grain yield on a per cob basis at harvest (October). Varieties demonstrating the greatest and least deviations in these measurements between treatments have been selected for preliminary molecular analysis (data not available at this time). Identifying early season growth characteristics and gene expression associated with maintaining high yield under weed stress conditions can, in the long term, lead to better understanding the mechanisms of crop tolerance, its heritability, and reducing weed control inputs

An Elemental Assay of Very, Extremely, and Ultra Metal-Poor Stars

We present a high-resolution elemental-abundance analysis for a sample of 23 very metal-poor (VMP; [Fe/H] < -2.0) stars, 12 of which are extremely metal-poor (EMP; [Fe/H] < -3.0), and 4 of which are ultra metal-poor (UMP; [Fe/H] < -4.0). These stars were targeted to explore differences in the abundance ratios for elements that constrain the possible astrophysical sites of element production, including Li, C, N, O, the alpha-elements, the iron-peak elements, and a number of neutron-capture elements. This sample substantially increases the number of known carbon-enhanced metal-poor (CEMP) and nitrogen-enhanced metal-poor (NEMP) stars -- our program stars include eight that are considered "normal" metal-poor stars, six CEMP-no stars, five CEMP-s stars, two CEMP-r stars, and two CEMP-r/s stars. One of the CEMP-$r$ stars and one of the CEMP-r/s stars are possible NEMP stars. We detect lithium for three of the six CEMP-no stars, all of which are Li-depleted with respect to the Spite plateau. The majority of the CEMP stars have [C/N] > 0. The stars with [C/N] < 0 suggest a larger degree of mixing; the few CEMP-no stars that exhibit this signature are only found at [Fe/H] < -3.4, a metallicity below which we also find the CEMP-no stars with large enhancements in Na, Mg, and Al. We confirm the existence of two plateaus in the absolute carbon abundances of CEMP stars, as suggested by Spite et al. We also present evidence for a "floor" in the absolute Ba abundances of CEMP-no stars at A(Ba)~ -2.0.Comment: 20 pages, 16 figures, Accepted for publication in Ap

Cavity Quantum Electrodynamics with Anderson-localized Modes

A major challenge in quantum optics and quantum information technology is to enhance the interaction between single photons and single quantum emitters. Highly engineered optical cavities are generally implemented requiring nanoscale fabrication precision. We demonstrate a fundamentally different approach in which disorder is used as a resource rather than a nuisance. We generate strongly confined Anderson-localized cavity modes by deliberately adding disorder to photonic crystal waveguides. The emission rate of a semiconductor quantum dot embedded in the waveguide is enhanced by a factor of 15 on resonance with the Anderson-localized mode and 94 % of the emitted single-photons couple to the mode. Disordered photonic media thus provide an efficient platform for quantum electrodynamics offering an approach to inherently disorder-robust quantum information devices

A large stellar evolution database for population synthesis studies: VI. White dwarf cooling sequences

We present a new set of cooling models and isochrones for both H- and He-atmosphere white dwarfs, incorporating accurate boundary conditions from detailed model atmosphere calculations, and carbon-oxygen chemical abundance profiles based on updated stellar evolution calculations from the BaSTI stellar evolution archive - a theoretical data center for the Virtual Observatory. We discuss and quantify the uncertainties in the cooling times predicted by the models, arising from the treatment of mixing during the central H- and He-burning phases, number of thermal pulses experienced by the progenitors, progenitor metallicity and the $^{12}C(\alpha,\gamma)^{16}O$ reaction rate. The largest sources of uncertainty turn out to be related to the treatment of convection during the last stages of the progenitor central He-burning phase, and the $^{12}C(\alpha,\gamma)^{16}O$ reaction rate. We compare our new models to previous calculations performed with the same stellar evolution code, and discuss their application to the estimate of the age of the solar neighborhood, and the interpretation of the observed number ratios between H- and He-atmosphere white dwarfs. The new white dwarf sequences and an extensive set of white dwarf isochrones that cover a large range of ages and progenitor metallicities are made publicly available at the official BaSTI website.Comment: 34 pages, 13 figures, The Astrophysical Journal, in pres

Integral Field Spectroscopy of the Central Regions of 3C 120: Evidence of a Past Merging Event

IFS combined with HST WFPC imaging were used to characterize the central regions of the Seyfert 1 radio galaxy 3C 120. We carried out the analysis of the data, deriving intensity maps of different emission lines and the continua at different wavelengths from the observed spectra. Applying a 2D modeling to the HST images we decoupled the nucleus and the host galaxy, and analyzed the host morphology. The host is a highly distorted bulge dominated galaxy, rich in substructures. We developed a new technique to model the IFS data extending the 2D modeling. Using this technique we separated the Seyfert nucleus and the host galaxy spectra, and derived a residual data cube with spectral and spatial information of the different structures in 3C 120. Three continuum-dominated structures (named A, B, and C) and other three extended emission line regions (EELRs, named E1, E2 and E3) are found in 3C 120 which does not follow the general behavior of a bulge dominated galaxy. We also found shells in the central kpc that may be remnants of a past merging event in this galaxy. The origin of E1 is most probably due to the interaction of the radio-jet of 3C 120 with the intergalactic medium. Structures A, B, and the shell at the southeast of the nucleus seem to correspond to a larger morphological clumpy structure that may be a tidal tail, consequence of the past merging event. We found a bright EELR (E2) in the innermost part of this tidal tail, nearby the nucleus, which shows a high ionization level. The kinematics of the E2 region and its connection to the tidal tail suggest that the tail has channeled gas from the outer regions to the center.Comment: 55 pages, 18 figures and 5 tables Accepted by AP

Tracking the COVID-19 Crisis with High-Resolution Transaction Data

We exploit high-frequency/high-resolution transaction data from BBVA, the second-largest bank in Spain, to analyse the dynamics of expenditure in Spain during the ongoing COVID-19 pandemic. Our main dataset consists of the universe of BBVA-mediated sales transactions from both credit cards and point-of-sales terminals, and totals 1.4 billion individual transactions since 2019. This dataset provides a unique opportunity to study the impact of the ongoing crisis in Spain—and the policies put in place to control it—on a daily basis. We find little shift in expenditure prior to the national lockdown, but then immediate, very large, and sustained expenditure reductions thereafter. Transaction metadata also allows us to study variation in these reductions across geography, sectors, and mode of sale (e.g. online/offline). We conclude that transaction data captures many salient patterns in how an economy reacts to shocks in real time, which makes its potential value to policy makers and researchers high

Caracterização funcional do sistema reprodutivo de Phragmipedium sargentianum ROLFE (Orchidaceae) em Santa Terezinha- Ba.

O objetivo do trabalho foi verificar e confirmar experimentalmente o sistema reprodutivo de P. sargentianum por meio de tratamentos de polinização em remanescente de Mata Atlântica submetida à ação antrópica. O sistema reprodutivo foi verificado no campo por meio da polinização aberta, autopolinização espontânea, autopolinização manual, polinização cruzada manual e agamospermia. A frutificação para a polinização aberta foi de 70%, a polinização cruzada manual e a autopolinização manual foi de 100%, não havendo formação de frutos para os demais tratamentos. A formação de frutos é dependente de vetores de pólen e o P. sargentianum responde com alto sucesso reprodutivo aos tratamentos de polinização cruzada manual e autopolinização manual. A polinização aberta demonstra eficiência dos polinizadores na área de estudo

Visitantes florais de Phragmipedium sargentianum Rolfe (Orchidaceae) em remanescente de Mata atlântica, Bahia, Brasil.

O objetivo do trabalho foi conhecer a diversidade e comportamento dos insetos visitantes florais de Phragmipedium sargentianum Rolfe no Monte da Pioneira, município de Santa Terezinha-BA. O estudo foi realizado por meio de observações em campo, sendo anotadas informações referentes ao comportamento e horário de visita dos insetos. A captura foi realiza por meio de sacos plásticos e os insetos acondicionados em câmara mortífera contendo acetato de etíla. Para identificação pelos especialistas, o material coletado foi fotografado e montado por via seca. Os principais visitantes florais do P. sargentianum foram o curculionídeo Stethobaris sp. e a abelha Trigona fuscipennis Friese, sendo este último o provável polinizador no local de estudo. O resultado serve como base para futuros trabalhos envolvendo a variação da fauna dos visitantes florais do P. sargentianum em diferentes altitudes no Monte da Pioneira

Evaluation of integrated daylighting and electric lighting design projects: Lessons learned from international case studies

This article presents and discusses the lessons learned from the monitoring of 25 integrated daylighting and electric lighting international case study projects. The case studies consist of real occupied buildings that have been monitored as part of the International Energy Agency (IEA) SHC Task 61/EBC Annex 77 Programme. The general goal of the case studies was to balance lighting energy use with occupants’ visual and non-visual requirements. This was achieved using innovative solutions for daylighting and electric lighting with advanced controls, but also implementing simple and out-of-the-box strategies. The findings suggest that energy demands for lighting can significantly be reduced by combining sensible daylight provision, efficient lighting sources, and advances in controls. Yet, the effective achievement of project goals requires adequate monitoring, fine-tuning, and verification. The findings also suggest that the adoption of “integrative” lighting – that is, lighting systems that address both visual and non-visual responses – is getting increasingly popular. Catering to non-visual requirements will likely drive further innovation in lighting technology. Currently, there is limited investment available for developing daylighting systems for integrative lighting, and the current related electric strategies often come at the risk of energy rebound effects. Overall, providing daylighting and understanding user requirements are fundamental steps towards achieving quality projects, with potential benefits beyond saving energy

Scaling behavior of the dipole coupling energy in two-dimensional disordered magnetic nanostructures

Numerical calculations of the average dipole-coupling energy $\bar E_\mathrm{dip}$ in two-dimensional disordered magnetic nanostructures are performed as function of the particle coverage $C$. We observe that $\bar E_\mathrm{dip}$ scales as $\bar E_\mathrm{dip}\propto C^{\alpha^*}$ with an unusually small exponent $\alpha^*\simeq 0.8$--1.0 for coverages $C\lesssim20$. This behavior is shown to be primarly given by the contributions of particle pairs at short distances, which is intrinsically related to the presence of an appreciable degree of disorder. The value of $\alpha^*$ is found to be sensitive to the magnetic arrangement within the nanostructure and to the degree of disorder. For large coverages $C\gtrsim20$ we obtain $\bar E_\mathrm{dip}\propto C^\alpha$ with $\alpha=3/2$, in agreement with the straighforward scaling of the dipole coupling as in a periodic particle setup. Taking into account the effect of single-particle anisotropies, we show that the scaling exponent can be used as a criterion to distinguish between weakly interacting ($\alpha^* \simeq 1.0$) and strongly interacting ($\alpha^* \simeq 0.8$) particle ensembles as function of coverage.Comment: accepted for publication in Phys.Rev.