Intrinsic Optical and Electronic Properties from Quantitative Analysis of Plasmonic Semiconductor Nanocrystal Ensemble Optical Extinction

The optical extinction spectra arising from localized surface plasmon resonance in doped semiconductor nanocrystals (NCs) have intensities and lineshapes determined by free charge carrier concentrations and the various mechanisms for damping the oscillation of those free carriers. However, these intrinsic properties are convoluted by heterogeneous broadening when measuring spectra of ensembles. We reveal that the traditional Drude approximation is not equipped to fit spectra from a heterogeneous ensemble of doped semiconductor NCs and produces fit results that violate Mie scattering theory. The heterogeneous ensemble Drude approximation (HEDA) model rectifies this issue by accounting for ensemble heterogeneity and near-surface depletion. The HEDA model is applied to tin-doped indium oxide NCs for a range of sizes and doping levels but we expect it can be employed for any isotropic plasmonic particles in the quasistatic regime. It captures individual NC optical properties and their contributions to the ensemble spectra thereby enabling the analysis of intrinsic NC properties from an ensemble measurement. Quality factors for the average NC in each ensemble are quantified and found to be notably higher than those of the ensemble. Carrier mobility and conductivity derived from HEDA fits matches that measured in the bulk thin film literature

Plantas de cobertura de solo para sistema plantio direto.

A camada de palha, sobre o solo, e essencial para o sucesso do Sistema Plantio Direto (SPD). Cria um ambiente extremamente favoravel as condicoes fisicas, quimicas e biologicas do solo contribuindo para o controle de plantas daninhas, estabilizacao da producao e recuperacao ou manutencao da qualidade do solo. O sistema de rotacao e sucessao de culturas deve ser adequado para permitir a manutencao de uma cobertura minima do solo com palha. Na escolha destas plantas, e fator decisivo conhecer a sua adaptacao a regiao e sua habilidade em crescer num ambiente menos favoravel, uma vez que as culturas comerciais sao estabelecidas nas epocas mais propicias. Isto e especialmente verdade nas condicoes de Brasil Central, onde o inverno e seco, ao passo que na regiao Sul, de inverno umido, nao existe essa limitacao e ha maior opcao de plantas adaptadas as condicoes do inverno. Existem muitas plantas de cobertura para as diferentes regioes edafoclimaticas do Brasil, e a experiencia local e decisiva nesta selecao. Em qualquer situacao, deve-se ter sempre em mente que nao existe uma planta milagrosa e que o ideal e ter mais de uma dessas especies no sistema de producao, onde busca-se aliar renda a preservacao ambiental

Tooth Discoloration in Patients With Neonatal Diabetes After Transfer Onto Glibenclamide: A previously unreported side effect

PublishedJournal ArticleMulticenter StudyResearch Support, N.I.H., ExtramuralResearch Support, Non-U.S. Gov'tOBJECTIVE To assess if tooth discoloration is a novel side effect of sulfonylurea therapy in patients with permanent neonatal diabetes due to mutations in KCNJ11. RESEARCH DESIGN AND METHODS A total of 67 patients with a known KCNJ11 mutation who had been successfully transferred from insulin injections onto oral sulfonylureas were contacted and asked about the development of tooth discoloration after transfer. RESULTS Altered tooth appearance was identified in 5 of the 67 patients. This was variable in severity, ranging from mild discoloration/staining (n = 4) to loss of enamel (n = 1) and was only seen in patients taking glibenclamide (glyburide). CONCLUSIONS These previously unreported side effects may relate to the developing tooth and/or to the high local concentrations in the children who frequently chewed glibenclamide tablets or took it as a concentrated solution. Given the multiple benefits of sulfonylurea treatment for patients with activating KCNJ11 mutations, this association warrants further investigation but should not preclude such treatment.This work was funded by the Welcome Trust (grant 067463/Z/2/Z), National Institutes of Health Grants DK-44752 and DK-20595, and a gift from the Kovler Family Foundation. S.E.F. is the Sir Graham Wilkins, Peninsula Medical School Research Fellow. A.T.H. is a Welcome Trust Research Leave Fellow. O.R.-C. was supported by an “Ayuda para contratos post-Formacio´n Sanitaria Especializada” from the “Instituto de Salud Carlos III” (FIS CM06/00013

Spatio-temporal variation of the urban heat island in Santiago, Chile during summers 2005–2017

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Urban heat islands (UHIs) can present significant risks to human health. Santiago, Chile has around 7 million residents, concentrated in an average density of 480 people/km2. During the last few summer seasons, the highest extreme maximum temperatures in over 100 years have been recorded. Given the projections in temperature increase for this metropolitan region over the next 50 years, the Santiago UHI could have an important impact on the health and stress of the general population. We studied the presence and spatial variability of UHIs in Santiago during the summer seasons from 2005 to 2017 using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery and data from nine meteorological stations. Simple regression models, geographic weighted regression (GWR) models and geostatistical interpolations were used to find nocturnal thermal differences in UHIs of up to 9◦ C, as well as increases in the magnitude and extension of the daytime heat island from summer 2014 to 2017. Understanding the behavior of the UHI of Santiago, Chile, is important for urban planners and local decision makers. Additionally, understanding the spatial pattern of the UHI could improve knowledge about how urban areas experience and could mitigate climate change

Myc depletion induces a pluripotent dormant state mimicking diapause

Mouse embryonic stem cells (ESCs) are maintained in a naive ground state of pluripotency in the presence of MEK and GSK3 inhibitors. Here, we show that ground-state ESCs express low Myc levels. Deletion of both c-myc and N-myc (dKO) or pharmacological inhibition of Myc activity strongly decreases transcription, splicing, and protein synthesis, leading to proliferation arrest. This process is reversible and occurs without affecting pluripotency, suggesting that Myc-depleted stem cells enter a state of dormancy similar to embryonic diapause. Indeed, c-Myc is depleted in diapaused blastocysts, and the differential expression signatures of dKO ESCs and diapaused epiblasts are remarkably similar. Following Myc inhibition, pre-implantation blastocysts enter biosynthetic dormancy but can progress through their normal developmental program after transfer into pseudo-pregnant recipients. Our study shows that Myc controls the biosynthetic machinery of stem cells without affecting their potency, thus regulating their entry and exit from the dormant state.This work was supported by the FOR2033 and SFB873 funded by the Deutsche Forschungsgemeinschaft (DFG), the Dietmar Hopp Foundation (all to A.T.), and the Wellcome Trust (to A.S.)

Permanent Neonatal Diabetes Caused by Creation of an Ectopic Splice Site within the INS Gene

PublishedCase ReportsJournal ArticleResearch Support, Non-U.S. Gov'tBACKGROUND: The aim of this study was to characterize the genetic etiology in a patient who presented with permanent neonatal diabetes at 2 months of age. METHODOLOGY/PRINCIPAL FINDINGS: Regulatory elements and coding exons 2 and 3 of the INS gene were amplified and sequenced from genomic and complementary DNA samples. A novel heterozygous INS mutation within the terminal intron of the gene was identified in the proband and her affected father. This mutation introduces an ectopic splice site leading to the insertion of 29 nucleotides from the intronic sequence into the mature mRNA, which results in a longer and abnormal transcript. CONCLUSIONS/SIGNIFICANCE: This study highlights the importance of routinely sequencing the exon-intron boundaries and the need to carry out additional studies to confirm the pathogenicity of any identified intronic genetic variants.Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM)Instituto de Salud Carlos III of the Spanish Ministry of HealthFIS-programsWellcome Trus

Escaping the climate policy uncertainty trap: options contracts for REDD+

Climate policy uncertainty significantly hinders investments in low-carbon technologies, and the global community is behind schedule to curb carbon emissions. Strong actions will be necessary to limit the increase in global temperatures, and continued delays create risks of escalating climate change damages and future policy costs. These risks are system-wide, long-term and large-scale and thus hard to diversify across firms. Because of its unique scale, cost structure and near-term availability, Reducing Emissions from Deforestation and forest Degradation in developing countries (REDD+) has significant potential to help manage climate policy risks and facilitate the transition to lower greenhouse gas emissions. ‘Call’ options contracts in the form of the right but not the obligation to buy high-quality emissions reduction credits from jurisdictional REDD+ programmes at a predetermined price per ton of CO2 could help unlock this potential despite the current lack of carbon markets that accept REDD+ for compliance. This approach could provide a globally important cost-containment mechanism and insurance for firms against higher future carbon prices, while channelling finance to avoid deforestation until policy uncertainties decline and carbon markets scale up

Atomic-resolution spectroscopic imaging of ensembles of nanocatalyst particles across the life of a fuel cell

The thousandfold increase in data-collection speed enabled by aberration-corrected optics allows us to overcome an electron microscopy paradox - how to obtain atomic-resolution chemical structure in individual nanoparticles, yet record a statistically significant sample from an inhomogeneous population. This allowed us to map hundreds of Pt-Co nanoparticles to show atomic-scale elemental distributions across different stages of the catalyst aging in a proton-exchange-membrane fuel cell, and relate Pt-shell thickness to treatment, particle size, surface orientation, and ordering.Comment: 28 pages, 5 figures, accepted, nano letter

Recessive mutations in the INS gene result in neonatal diabetes through reduced insulin biosynthesis

Heterozygous coding mutations in the INS gene that encodes preproinsulin were recently shown to be an important cause of permanent neonatal diabetes. These dominantly acting mutations prevent normal folding of proinsulin, which leads to beta-cell death through endoplasmic reticulum stress and apoptosis. We now report 10 different recessive INS mutations in 15 probands with neonatal diabetes. Functional studies showed that recessive mutations resulted in diabetes because of decreased insulin biosynthesis through distinct mechanisms, including gene deletion, lack of the translation initiation signal, and altered mRNA stability because of the disruption of a polyadenylation signal. A subset of recessive mutations caused abnormal INS transcription, including the deletion of the C1 and E1 cis regulatory elements, or three different single base-pair substitutions in a CC dinucleotide sequence located between E1 and A1 elements. In keeping with an earlier and more severe beta-cell defect, patients with recessive INS mutations had a lower birth weight (-3.2 SD score vs. -2.0 SD score) and were diagnosed earlier (median 1 week vs. 10 weeks) compared to those with dominant INS mutations. Mutations in the insulin gene can therefore result in neonatal diabetes as a result of two contrasting pathogenic mechanisms. Moreover, the recessively inherited mutations provide a genetic demonstration of the essential role of multiple sequence elements that regulate the biosynthesis of insulin in man