Are high-throughput root phenotyping platforms suitable for informing root system architecture models with genotype-specific parameters? An evaluation based on the root model ArchiSimple and a small panel of wheat cultivars.

Given the difficulties in accessing plant roots in situ, high-throughput root phenotyping (HTRP) platforms under controlled conditions have been developed to meet the growing demand for characterizing root system architecture (RSA) for genetic analyses. However, a proper evaluation of their capacity to provide the same estimates for strictly identical root traits across platforms has never been achieved. In this study, we performed such an evaluation based on six major parameters of the RSA model ArchiSimple, using a diversity panel of 14 bread wheat cultivars in two HTRP platforms that had different growth media and non-destructive imaging systems together with a conventional set-up that had a solid growth medium and destructive sampling. Significant effects of the experimental set-up were found for all the parameters and no significant correlations across the diversity panel among the three set-ups could be detected. Differences in temperature, irradiance, and/or the medium in which the plants were growing might partly explain both the differences in the parameter values across the experiments as well as the genotype × set-up interactions. Furthermore, the values and the rankings across genotypes of only a subset of parameters were conserved between contrasting growth stages. As the parameters chosen for our analysis are root traits that have strong impacts on RSA and are close to parameters used in a majority of RSA models, our results highlight the need to carefully consider both developmental and environmental drivers in root phenomics studies.

Amplitude Modeling of Specular Multipath Components for Robust Indoor Localization.

Ultra-Wide Bandwidth (UWB) and mm-wave radio systems can resolve specular multipath components (SMCs) from estimated channel impulse response measurements. A geometric model can describe the delays, angles-of-arrival, and angles-of-departure of these SMCs, allowing for a prediction of these channel features. For the modeling of the amplitudes of the SMCs, a data-driven approach has been proposed recently, using Gaussian Process Regression (GPR) to map and predict the SMC amplitudes. In this paper, the applicability of the proposed multipath-resolved, GPR-based channel model is analyzed by studying features of the propagation channel from a set of channel measurements. The features analyzed include the energy capture of the modeled SMCs, the number of resolvable SMCs, and the ranging information that could be extracted from the SMCs. The second contribution of the paper concerns the potential applicability of the channel model for a multipath-resolved, single-anchor positioning system. The predicted channel knowledge is used to evaluate the measurement likelihood function at candidate positions throughout the environment. It is shown that the environmental awareness created by the multipath-resolved, GPR-based channel model yields higher robustness against position estimation outliers.

Graph analysis of proton conduction pathways in scandium-doped barium zirconate.

Understanding the relationship between the acceptor dopant size and proton conductivity in barium zirconate, BaZrO3, is important for maximizing efficiency in this promising fuel cell material. While proton conduction pathways with larger YZr ' and smaller AlZr ' defects have been explored, proton pathways with ScZr ', a defect of comparable size to the replaced ion, have not been investigated using centrality measures, periodic pathway searches, and kinetic Monte Carlo (KMC). Centrality measures in BaSc0.125Zr0.875O3 highlight a trapping region by ScZr ' and scattered high centrality regions on undoped planes. Connected long-range high centrality regions are found mainly in undoped planes for BaAl0.125Zr0.875O3 and in the dopant planes for BaY0.125Zr0.875O3. The best long-range proton conduction periodic pathways in AlZr ' and ScZr ' systems travel between dopant planes, while those for yttrium-doped BaZrO3 remained on dopant planes. KMC trajectories at 1000 K show long-range proton conduction barriers of 0.86 eV, 0.52 eV, and 0.25 eV for AlZr ', ScZr ', and YZr ' systems, respectively. Long-range periodic conduction highway limiting barrier averages correlate well with the connectivity of the most central regions in each system but ignore diffusion around the dopant and through other high centrality regions. BaSc0.125Zr0.875O3 shows an intermediate overall conduction barrier limited by trapping, which earlier experiments and simulations suggest that it can be mitigated with increased oxygen vacancy concentration.

A Novel Heme Transporter from the Energy Coupling Factor Family Is Vital for Group A Streptococcus Colonization and Infections.

Group A streptococcus (GAS) produces millions of infections worldwide, including mild mucosal infections, postinfection sequelae, and life-threatening invasive diseases. During infection, GAS readily acquires nutritional iron from host heme and hemoproteins. Here, we identified a new heme importer, named SiaFGH, and investigated its role in GAS pathophysiology. The SiaFGH proteins belong to a group of transporters with an unknown ligand from the recently described family of energy coupling factors (ECFs). A siaFGH deletion mutant exhibited high streptonigrin resistance compared to the parental strain, suggesting that iron ions or an iron complex is the likely ligand. Iron uptake and inductively coupled plasma mass spectrometry (ICP-MS) studies showed that the loss of siaFGH did not impact GAS import of ferric or ferrous iron, but the mutant was impaired in using hemoglobin iron for growth. Analysis of cells growing on hemoglobin iron revealed a substantial decrease in the cellular heme content in the mutant compared to the complemented strain. The induction of the siaFGH genes in trans resulted in the induction of heme uptake. The siaFGH mutant exhibited a significant impairment in murine models of mucosal colonization and systemic infection. Together, the data show that SiaFGH is a new type of heme importer that is key for GAS use of host hemoproteins and that this system is imperative for bacterial colonization and invasive infection.IMPORTANCE ECF systems are new transporters that take up various vitamins, cobalt, or nickel with a high affinity. Here, we establish the GAS SiaFGH proteins as a new ECF module that imports heme and demonstrate its importance in virulence. SiaFGH is the first heme ECF system described in bacteria. We identified homologous systems in the genomes of related pathogens from the Firmicutes phylum. Notably, GAS and other pathogens that use a SiaFGH-type importer rely on host hemoproteins for a source of iron during infection. Hence, recognizing the function of this noncanonical ABC transporter in heme acquisition and the critical role that it plays in disease has broad implications.

Consumption of antibiotics in a small Pacific island nation: Samoa

High levels of antibiotic use contribute to development of antibiotic resistance. There is little known about levels of antibiotic use in Samoa, although anecdotally, there are high levels of use, and a strain of methicillin-resistant Staphylococcus aureus may have developed there. The study aimed to gather basic data on levels of antibiotic use in Samoa. All those who import medicines into Samoa were interviewed; invoices, prescription records in hospitals, pharmacies and health centres were reviewed; and prospective observation was carried out in private pharmacies. Analysis of orders made in one year provided an estimate of overall antibiotic consumption of 37.3 Defined Daily Doses (DDDs) per 1000 inhabitant days. Penicillins comprised 63% of DDDs used. Antibiotics were around a third of all prescribed drugs in hospitals and pharmacies, and 44% of those dispensed in health centres. Approximately two-thirds of prescriptions dispensed included an antibiotic. A quarter of antibiotic sales in pharmacies were without a prescription. Samoa has high rates of use of antibiotics and very high reliance on penicillins, compared to other developing countries. Levels of prescribing are high compared with other developing nations. It is feasible to calculate total consumption of medicines in very small developing nations (AU)

El uso de altas cantidades de antibióticos contribuye al desarrollo de resistencias a antibióticos. Se sabe poco sobre el consumo de antibiótico en Samoa, aunque paradójicamente, hay elevados niveles de consumo y puede haberse instalado una cepa de Estafilococo aureus metilcilin-resistente. El estudio intentó reunir datos básicos sobre los niveles de consumo de antibióticos en Samoa. Se entrevistó a todos los que importan antibióticos en Samoa; se revisaron las facturas, los registros de prescripciones de hospitales, de farmacias y de centros de salud; y se realizó una observación prospectiva en las farmacias privadas. El análisis de las recetas de un año proporcionó una estimación de consumo total anual de 37,3 Dosis Diarias Definidas (DDD) por 1000 habitantes y día. Las penicilinas suponían el 63% de las DDD utilizadas. Los antibióticos suponían un tercio de todos los medicamentos prescritos en hospitales y farmacias, y el 44% de los dispensados en centros de salud. Aproximadamente dos tercios de las recetas dispensadas incluían un antibiótico. La cuarta parte de las dispensaciones de antibióticos eran sin receta. Samoa tiene una alta tasa de uso de antibióticos y mucha confianza en las penicilinas, comparada con otros países en vías de desarrollo. Los niveles de prescripción son altos comparados con otros países en desarrollo. Es factible calcular el consumo total de medicamento sen países muy pequeños en vías de desarrollo (AU)

Consumption of antibiotics in a small Pacific island nation: Samoa.

High levels of antibiotic use contribute to development of antibiotic resistance. There is little known about levels of antibiotic use in Samoa, although anecdotally, there are high levels of use, and a strain of methicillin-resistant Staphylococcus aureus may have developed there. The study aimed to gather basic data on levels of antibiotic use in Samoa. All those who import medicines into Samoa were interviewed; invoices, prescription records in hospitals, pharmacies and health centres were reviewed; and prospective observation was carried out in private pharmacies. Analysis of orders made in one year provided an estimate of overall antibiotic consumption of 37.3 Defined Daily Doses (DDDs) per 1000 inhabitant days. Penicillins comprised 63% of DDDs used. Antibiotics were around a third of all prescribed drugs in hospitals and pharmacies, and 44% of those dispensed in health centres. Approximately two-thirds of prescriptions dispensed included an antibiotic. A quarter of antibiotic sales in pharmacies were without a prescription. Samoa has high rates of use of antibiotics and very high reliance on penicillins, compared to other developing countries. Levels of prescribing are high compared with other developing nations. It is feasible to calculate total consumption of medicines in very small developing nations.