Optical properties of nanocrystal films: blue shifted transitions as signature of strong coupling

We present a theoretical study at the atomistic level of the optical properties of semiconductor nanocrystal films. We investigate the dependence of the absorption coefficient on size, inter-dot separation, surface stoichiometry and morphology, temperature, position of the Fermi level and light polarization. Our results show that, counter-intuitively, huge blue shifts are expected in some intra-band transitions for strongly coupled arrays, in contrast with the predicted and observed red shift of the band gap absorption in such systems. Furthermore, we find that the energies of such transitions can be tuned within a range of several hundreds of meV, just by engineering the inter-dot separation in the film through the choice of appropriately sized capping ligands. Finally we discuss the application of this effect to nanocrystal-based intermediate-band solar cells

Improving Latin American soil information database for digital soil mapping enhances its usability and scalability

Spatial soil databases can help model complex phenomena in which soils are decisive, for example, evaluating agricultural potential or estimating carbon storage capacity. The Soil Information System for Latin America and the Caribbean, SISLAC, is a regional initiative promoted by the FAO's South American Soil Partnership to contribute to the sustainable management of soil. SISLAC includes data coming from 49,084 soil profiles distributed unevenly across the continent, making it the region's largest soil database. However, some problems hinder its usages, such as the quality of the data and its high dimensionality. The objective of this research is twofold. First, to evaluate the quality of SISLAC and its data values and generate a new, improved version that meets the minimum quality requirements to be used by different interests or practical applications. Second, to demonstrate the potential of improved soil profile databases to generate more accurate information on soil properties, by conducting a case study to estimate the spatial variability of the percentage of soil organic carbon using 192 profiles in a 1473 km2 region located in the department of Valle del Cauca, Colombia. The findings show that 15 percent of the existing soil profiles had an inaccurate description of the diagnostic horizons. Further correction of an 4.5 additional percent of existing inconsistencies improved overall data quality. The improved database consists of 41,691 profiles and is available for public use at ttps://doi.org/10.5281/zenodo.6540710 (Díaz-Guadarrama, S. & Guevara, M., 2022). The updated profiles were segmented using algorithms for quantitative pedology to estimate the spatial variability. We generated segments one centimeter thick along with each soil profile data, then the values of these segments were adjusted using a spline-type function to enhance vertical continuity and reliability. Vertical variability was estimated up to 150 cm in-depth, while ordinary kriging predicts horizontal variability at three depth intervals, 0 to 5, 5 to 15, and 15 to 30 cm, at 250 m-spatial resolution, following the standards of the GlobalSoilMap project. Finally, the leave-one-out cross validation provides information for evaluating the kriging model performance, obtaining values for the RMSE index between 1.77% and 1.79% and the R2 index greater than 0.5. The results show the usability of SISLAC database to generate spatial information on soil properties and suggest further efforts to collect a more significant amount of data to guide sustainable soil management.Fil: Diaz Guadamarra, Sergio. Universidad Nacional de Colombia. Facultad de Ciencias Agrarias. Departamento de Agronomía; ColombiaFil: Lizarazo, Iván. Universidad Nacional de Colombia. Facultad de Ciencias Agrarias. Departamento de Agronomía; ColombiaFil: Guevara, Mario. Universidad Nacional Autónoma de México. Campus Juriquilla. Centro de Geociencias; MéxicoFil: Guevara, Mario. Universidad Nacional Autónoma de México.Campus Juriquilla. Centro de Geociencias; México. United States Department of Agriculture. Soil Salinity National Laboratory, Estados UnidosFil: Angelini, Marcos Esteban. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Suelos; Argentina. Wageningen University. Soil Geography and Landscape Group; Países Bajos. International Soil Reference and Information Centre. World Soil Information; Países BajosFil: Araujo Carrillo, Gustavo A. Corporación Colombiana de Investigación Agropecuaria AGROSAVIA; ColombiaFil: Argeñal, Jainer. Universidad Nacional Autónoma de Honduras. Facultad de Ciencias; Honduras.Fil: Armas, Daphne. Universidad de Almería. Departamento de Agronomía, Edif. CITEIIB, España.Fil: Balsa, Rafael A. Ministerio de Desarrollo Agrario y Riego. Dirección General de Asuntos Ambientales Agrarios, Perú.Fil: Bolivar, Adriana. Instituto Geográfico Agustín Codazzi. Subdirección Agrología; ColombiaFil: Bustamante, Nelson. Servicio Agrícola y Ganadero; Chile.Fil: Dart, Ricardo O. Embrapa Solos; BrasilFil: Dell Acqua, Martín. Ministerio de Ganadería, Agricultura y Pesca. Dirección General de Recursos Naturales; UruguayFil: Lencina, Arnulfo. Universidad Nacional de Asunción. Facultad de Ciencias Agrarias; ParaguayFil: Figueredo, Hernán. Sociedad Boliviana de la Ciencia del Suelo; Bolivia.Fil: Fontes, Fernando. Ministerio de Ganadería, Agricultura y Pesca. Dirección General de Recursos Naturales; UruguayFil: Gutierrez Diaz, Joan S. Aarhus University. Faculty of Science and Technology,.Department of Agroecology; DinamarcaFil: Jiménez, Wilmer. Ministerio de Agricultura y Ganadería; Ecuador.Fil: Rodriguez, Dario Martin. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Suelos; ArgentinaFil: Schulz, Guillermo. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Suelos; ArgentinaFil: Tenti Vuegen, Leonardo Mauricio. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Suelos; Argentin

Chloramphenicol Selection of IS10 Transposition in the cat Promoter Region of Widely Used Cloning Vectors

The widely used pSU8 family of cloning vectors is based on a p15A replicon and a chloramphenicol acetyltransferase (cat) gene conferring chloramphenicol resistance. We frequently observed an increase in the size of plasmids derived from these vectors. Analysis of the bigger molecular species shows that they have an IS10 copy inserted at a specific site between the promoter and the cat open reading frame. Promoter activity from both ends of IS10 has been reported, suggesting that the insertion events could lead to higher CAT production. Insertions were observed in certain constructions containing inserts that could lead to plasmid instability. To test the possibility that IS10 insertions were selected as a response to chloramphenicol selection, we have grown these constructs in the presence of different amounts of antibiotic and we observed that insertions arise promptly under higher chloramphenicol selective pressure. IS10 is present in many E. coli laboratory strains, so the possibility of insertion in constructions involving cat-containing vectors should be taken into account. Using lower chloramphenicol concentrations could solve this problem

Bacterial Diversity in Oral Samples of Children in Niger with Acute Noma, Acute Necrotizing Gingivitis, and Healthy Controls

Noma is a devastating gangrenous disease that leads to severe facial disfigurement, but its cause remains unknown. It is associated with high morbidity and mortality and affects almost exclusively young children living in remote areas of developing countries, particularly in Africa. Several factors have been linked to the disease, including malnutrition, immune dysfunction, lack of oral hygiene, and lesions of the mucosal gingival barrier, particularly the presence of acute necrotizing gingivitis, and a potentially non-identified bacterial factor acting as a trigger for the disease. This study assessed the total bacterial diversity present in 69 oral samples of 55 children in Niger with or without acute noma or acute necrotizing gingivitis using culture-independent molecular methods. Analysis of bacterial composition and frequency showed that diseased and healthy site bacterial communities are composed of similar bacteria, but differ in the prevalence of a limited group of phylotypes. We failed to identify a causative infectious agent for noma or acute necrotizing gingivitis as the most plausible pathogens for both conditions were present also in sizeable numbers in healthy subjects. Most likely, the disease is initiated by a synergistic combination of several bacterial species, and not a single agent

Neurobiology of rodent self-grooming and its value for translational neuroscience

Self-grooming is a complex innate behaviour with an evolutionarily conserved sequencing pattern and is one of the most frequently performed behavioural activities in rodents. In this Review, we discuss the neurobiology of rodent self-grooming, and we highlight studies of rodent models of neuropsychiatric disorders-including models of autism spectrum disorder and obsessive compulsive disorder-that have assessed self-grooming phenotypes. We suggest that rodent self-grooming may be a useful measure of repetitive behaviour in such models, and therefore of value to translational psychiatry. Assessment of rodent self-grooming may also be useful for understanding the neural circuits that are involved in complex sequential patterns of action.National Institutes of Health (U.S.) (Grant NS025529)National Institutes of Health (U.S.) (Grant HD028341)National Institutes of Health (U.S.) (Grant MH060379

Autoantibodies against type I IFNs in patients with life-threatening COVID-19

Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-w (IFN-w) (13 patients), against the 13 types of IFN-a (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men

CuInS2/ZnS-based QLED design and modelling for automotive lighting systems

This work reports the design, manufacturing and numerical simulation approach of a 6-pixel (4.5mm2/pixel) electroluminescent quantum dot light emitting device (QLED) based on CuInS2/ZnS quantum dots as an active layer. Following a conventional thin-film deposition multilayer approach, the QLED device was fabricated. In addition, the electrical I-V curve was measured for each pixel independently, observing how the fabrication process and layer thickness have an influence in the shape of the plot. This experimental device fabricated, enabled us to create a computational model for the QLED based on the Transfer Hamiltonian approach to calculate the current density J(mA/cm2), the band diagram of the system, and the accumulated charge distribution. Besides, it is worth highlighting that the simulator allows the possibility to study the influence of different parameters of the QLED structure like the junction capacitance between the distinct multilayer set. Specifically, we found that Anode-HIL interface capacitance has a greater influence in the I-V plot shape. That junction capacitance plays an important role in the current increase and the QLED turn-on value when a forward voltage is applied to the device. Thanks to the simulator, that influence could be put under control by the selection of the optimal thickness and transport layers during the experimental fabrication process. This work is remarkable since it achieves to fit simulation and experiment results in an accurate way for electroluminescent QLED devices; particularly the simulation of the device current, which is critical when designing the automotive electronics to control these new nanotechnology lighting devices in the future

Efficient Mobility Calculation for Quantum Dot Superlattices

The aim of this work is to calculate the electron mobility in a two dimensional periodic superlattice of quantum dots containing different-sized quantum dots. A simulation has been carried out using the tight binding method for calculating the energy levels and eigenstates of the periodic lattice. The different sized, non-periodic quantum dots are introduced as perturbed potential scattering centers and their effect has been included in the Fermi distribution to obtain a temperature dependent mobility tensor for easy comparison with experimental data

Identification of research priorities in infertility and assisted reproduction: an international, multicentre study

Research question: What are the main research interests among patients of assisted reproductive technologies (ART)? Design: Cross-sectional study consisting of an anonymous online survey sent to 2112 patients from eight centres in four countries in 2018. Patients were asked to identify research questions relevant to them in the field of infertility and ART. Answers were categorized into topics and ranked by frequency. A long list of the top 30 research topics was extracted from the aggregate results, from which a short list of the top 10 research topics was created. Ten research questions were finally formulated. Results: A total of 945 responses were analysed. Main interests were side-effects, success rates, infertility prevention and emotional support. The 10 research questions were: 1. What are the side-effects of drugs used in ART treatments? (51.6%). 2. What are the most effective methods to cope with infertility from the psychological point of view? (35.7%). 3. What effects could diet have on fertility? (25.9%). 4. What are ART success rates per clinical profile? (24.8%). 5. Are there some habits and lifestyle factors that could prevent infertility? (20.0%). 6. What are the long-term risks associated with ART in mother and child? (18.5%). 7. Are alternative therapies such as acupuncture, yoga and meditation effective to treat/prevent infertility? (18.5%). 8. What is the impact of exercise on fertility? (15.4%). 9. How does oocyte quantity and quality affect fertility? (9.5%). 10. What are the genetic patterns or hereditary conditions causing/related to infertility? (9.5%). Conclusions: Researchers and clinicians should keep in mind that, in addition to success rates and safety, patients greatly value research into causes, prevention and emotional aspects of infertility