Practical Path-based Bayesian Optimization

There has been a surge in interest in data-driven experimental design with applications to chemical engineering and drug manufacturing. Bayesian optimization (BO) has proven to be adaptable to such cases, since we can model the reactions of interest as expensive black-box functions. Sometimes, the cost of this black-box functions can be separated into two parts: (a) the cost of the experiment itself, and (b) the cost of changing the input parameters. In this short paper, we extend the SnAKe algorithm to deal with both types of costs simultaneously. We further propose extensions to the case of a maximum allowable input change, as well as to the multi-objective setting.Comment: 6 main pages, 12 with references and appendix. 4 figures, 2 tables. To appear in NeurIPS 2023 Workshop on Adaptive Experimental Design and Active Learning in the Real Worl

Open-orbit induced low field extremely large magnetoresistance in graphene/h-BN superlattices

We report intriguing and hitherto overlooked low-field room temperature extremely large magnetoresistance (XMR) patterns in graphene/hexagonal boron nitride (h-BN) superlattices that emerge due to the existence of open orbits within each miniband. This finding is set against the backdrop of the experimental discovery of the Hofstadter butterfly in moir superlattices, which has sparked considerable interest in the fractal quantum Hall regime. To cope with the challenge of deciphering the low magnetic field dynamics of moir minibands, we utilize a novel semi-classical calculation method, grounded in zero-field Fermi contours, to predict the nontrivial behavior of the Landau-level spectrum. This is compared with fully quantum simulations, enabling an in-depth and contrasted analysis of transport measurements in high-quality graphene-hBN superlattices. Our results not only highlight the primary observation of the open-orbit induced XMR in this system but also shed new light on other intricate phenomena. These include the nuances of single miniband dynamics, evident through Lifshitz transitions, and the complex interplay of semiclassical and quantum effects between these minibands. Specifically, we document transport anomalies linked to trigonal warping, a semiclassical deviation from the expected linear characteristics of Landau levels, and magnetic breakdown phenomena indicative of quantum tunneling, all effects jointly contributing to the intricacies of a rich electronic landscape uncovered at low magnetic fields.Comment: 5 figure

Cloud adjustments from large-scale smoke-circulation interactions strongly modulate the southeast Atlantic stratocumulus-to-cumulus transition

Smoke from southern Africa blankets the southeast Atlantic Ocean from June&ndash;October, producing strong and competing aerosol radiative effects. Smoke effects on the transition between overcast stratocumulus and scattered cumulus clouds are investigated along a Lagrangian (air-mass-following) trajectory in regional climate and large eddy simulation models. Results are compared with observations from three recent field campaigns that took place in August 2017: ORACLES, CLARIFY, and LASIC. The case study is set up around the joint ORACLES-CLARIFY flight that took place near Ascension Island on 18 August 2017. Smoke sampled upstream on an ORACLES flight on 15 August 2017 likely entrained into the marine boundary layer later sampled during the joint flight. The case is first simulated with the WRF-CAM5 regional climate model in three distinct setups: 1) FireOn, in which smoke emissions and any resulting smoke-cloud-radiation interactions are included; 2) FireOff, in which no smoke emissions are included; and 3) RadOff, in which smoke emissions and their microphysical effects are included but aerosol does not interact directly with radiation. Over the course of the Lagrangian trajectory, differences in free tropospheric thermodynamic properties between FireOn and FireOff are nearly identical to those between FireOn and RadOff, showing that aerosol-radiation interactions are primarily responsible for the free tropospheric effects. These effects are non-intuitive: in addition to the expected heating within the core of the smoke plume, there is also a "banding" effect of cooler temperature (~1&ndash;2 K) and greatly enhanced moisture (&gt;2 g/kg) at plume top. This banding effect is caused by a vertical displacement of the former continental boundary layer in the free troposphere in the FireOn simulation resulting from anomalous diabatic heating due to smoke absorption of sunlight that manifests primarily as a few hundred m per day reduction in large-scale subsidence over the ocean. A large eddy simulation (LES) is then forced with free tropospheric fields taken from the outputs for the WRF-CAM5 FireOn and FireOff runs. Cases are run by selectively perturbing one variable (e.g., aerosol number concentration, temperature, moisture, vertical velocity) at a time to better understand the contributions from different indirect (microphysical), "large-scale" semi-direct (above-cloud thermodynamic and subsidence changes), and "local" semi-direct (below-cloud smoke absorption) effects. Despite a more than five-fold increase in cloud droplet number concentration when including smoke aerosol concentrations, minimal differences in cloud fraction evolution are simulated by the LES when comparing the base case to a perturbed aerosol case with identical thermodynamic and dynamic forcings. A factor-of-two decrease in background free tropospheric aerosol concentrations from the FireOff simulation shifts the cloud evolution from a classical entrainment-driven "deepening-warming" transition to trade cumulus to a precipitation-driven "drizzle-depletion" transition to open cells, however. The thermodynamic and dynamic changes caused by the WRF-simulated large-scale adjustments to smoke diabatic heating strongly influence cloud evolution in terms of both the rate of deepening (especially for changes in the inversion temperature jump and in subsidence) and in cloud fraction on the final day of the simulation (especially for the moisture "banding" effect). Such large-scale semi-direct effects would not have been possible to simulate using a small domain LES model alone.</p

Dispersión de residuos industriales en el subsuelo del barrio de La Almozara. Contexto ambiental y geomorfológico de distribución

El barrio de La Almozara (Zaragoza) nació al amparo del desarrollo de la Industrial Química de Zaragoza. Una de las actividades de esta empresa era la tostación de piritas para la obtención de ácido sulfúrico. Durante casi un siglo de actividad, los residuos producidos fueron utilizados para recrecer motas y elevar topográficamente La Almozara que se encuentra en la llanura de inundación del río Ebro. El desmantelamiento de las plantas no vino acompañado de la retirada de los residuos, que siguen presentes bajo parte de las zonas urbanas y parques. La interacción de las aguas de infiltración y dichos residuos ha propiciado la existencia de una pluma de contaminación bajo el barrio con aguas de pH 3 en el subsuelo. La distribución de residuos respondía a la oportunidad sin existir registros de la distribución de su vertido. Sin embargo, a partir de información oral, visitas a obras y análisis geomorfológicos de la zona de estudio, se ha podido realizar un mapa de susceptibilidad a la presencia de dichos residuos incorporando las distintas fuentes de información como herramienta predictiva de la eventual presencia de dichos residuos en un entorno actual urbano y como orientación para actuaciones que puedan desarrollarse en el futuro y que impliquen remoción o movimientos de tierra en la zona de estudio

Cartografía indirecta de residuos industriales del barrio de La Almozara (Zaragoza) por medio de la susceptibilidad magnética

En el subsuelo del barrio de La Almozara (Zaragoza) persisten residuos de la tostación de sulfuros de una antigua planta industrial que finalizó su actividad en la década de 1970. Los residuos generados no fueron retirados y es habitual su aparición en obras y en zonas de parque del barrio. Su aparición en superficie produce la dispersión eólica y la exposición aérea a dichos residuos con altos contenidos en As, Sb, Be, Cd, Co, Cr. Mo, Ni, Ag, Pb, Se, Hg y Zn. La susceptibilidad magnética de estos residuos presenta valores entre los 5000 y 50000 x 10-6 (SI) que contrasta con los valores de fondo natural local que presenta valores entre 10 y 100 x 10-6. Los valores de susceptibilidad magnética exhiben una gradación prácticamente continua entre los suelos naturales tipo y los residuos que define la presencia de procesos de mezcla entre los materiales naturales, antrópicos y los residuos existentes de las zonas de parque del barrio. Se define así la cartografía de susceptibilidad magnética como herramienta para la cartografía de la distribución de los residuos y de los materiales de mezcla con los materiales naturales de la zona de estudio

On the differences in the vertical distribution of modeled aerosol optical depth over the southeastern Atlantic

The southeastern Atlantic is home to an expansive smoke aerosol plume overlying a large cloud deck for approximately a third of the year. The aerosol plume is mainly attributed to the extensive biomass burning activities that occur in southern Africa. Current Earth system models (ESMs) reveal significant differences in their estimates of regional aerosol radiative effects over this region. Such large differences partially stem from uncertainties in the vertical distribution of aerosols in the troposphere. These uncertainties translate into different aerosol optical depths (AODs) in the planetary boundary layer (PBL) and the free troposphere (FT). This study examines differences of AOD fraction in the FT and AOD differences among ESMs (WRF-CAM5, WRF-FINN, GEOS-Chem, EAM-E3SM, ALADIN, GEOS-FP, and MERRA-2) and aircraft-based measurements from the NASA ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) field campaign. Models frequently define the PBL as the well-mixed surface-based layer, but this definition misses the upper parts of decoupled PBLs, in which most low-level clouds occur. To account for the presence of decoupled boundary layers in the models, the height of maximum vertical gradient of specific humidity profiles from each model is used to define PBL heights. Results indicate that the monthly mean contribution of AOD in the FT to the total-column AOD ranges from 44 % to 74 % in September 2016 and from 54 % to 71 % in August 2017 within the region bounded by 25∘ S–0∘ N–S and 15∘ W–15∘ E (excluding land) among the ESMs. ALADIN and GEOS-Chem show similar aerosol plume patterns to a derived above-cloud aerosol product from the Moderate Resolution Imaging Spectroradiometer (MODIS) during September 2016, but none of the models show a similar above-cloud plume pattern to MODIS in August 2017. Using the second-generation High Spectral Resolution Lidar (HSRL-2) to derive an aircraft-based constraint on the AOD and the fractional AOD, we found that WRF-CAM5 produces 40 % less AOD than those from the HSRL-2 measurements, but it performs well at separating AOD fraction between the FT and the PBL. AOD fractions in the FT for GEOS-Chem and EAM-E3SM are, respectively, 10 % and 15 % lower than the AOD fractions from the HSRL-2. Their similar mean AODs reflect a cancellation of high and low AOD biases. Compared with aircraft-based observations, GEOS-FP, MERRA-2, and ALADIN produce 24 %–36 % less AOD and tend to misplace more aerosols in the PBL. The models generally underestimate AODs for measured AODs that are above 0.8, indicating their limitations at reproducing high AODs. The differences in the absolute AOD, FT AOD, and the vertical apportioning of AOD in different models highlight the need to continue improving the accuracy of modeled AOD distributions. These differences affect the sign and magnitude of the net aerosol radiative forcing, especially when aerosols are in contact with clouds.</p

Pregnancy as a risk factor for severe influenza infection: an individual participant data meta-analysis

Background: WHO identifies pregnant women to be at increased risk for severe outcomes from influenza virus infections and recommends that they be prioritized for influenza vaccination. The evidence supporting this, however, is inconsistent. Ecologic studies in particular suggest more severe outcomes from influenza infection during pregnancy than studies based on individual patient data. Individual studies however may be underpowered and, as reported in a previous systematic review, confounding factors could not be adjusted for. We therefore conducted an individual participant data meta-analysis to assess the risk for severe outcomes of influenza infection in pregnant women while adjusting for other prognostic factors. Methods: We contacted authors of studies included in a recently published systematic review. We pooled the individual participant data of women of reproductive age and laboratory confirmation of influenza virus infection. We used a generalized linear mixed model and reported odds ratios (OR) and 95% confidence intervals (CI). Results: A total of 33 datasets with data on 186,656 individuals were available, including 36,498 eligible women of reproductive age and known pregnancy status. In the multivariable model, pregnancy was associated with a 7 times higher risk of hospital admission (OR 6.80, 95%CI 6.02–7.68), among patients receiving medical care as in- or outpatients, pregnancy was associated with a lower risk of admission to intensive care units (ICU; OR 0.57, 95%CI 0.48–0.69), and was not significantly associated with death (OR 1.00, 95%CI 0.75–1.34). Conclusions: Our study found a higher risk of influenza associated hospitalization among pregnant women as compared to non-pregnant women. We did not find a higher mortality rate or higher likelihood of ICU admission among pregnant women who sought medical care. However, this study did not address whether a true community based cohort of pregnant women is at higher risk of influenza associated complications.Fil: Mertz, Dominik. Mc Master University; CanadáFil: Lo, Calvin Ka Fung. Mc Master University; CanadáFil: Lytvyn, Lyubov. Mc Master University; CanadáFil: Ortiz, Justin R.. Organizacion Mundial de la Salud; ArgentinaFil: Loeb, Mark. Mc Master University; CanadáFil: Ang, Li Wei. Ministry of Health; SingapurFil: Anlikumar, Mehta Asmita. Amrita Vishwa Vidyapeetham; IndiaFil: Bonmarin, Isabelle. Santé publique; FranciaFil: Borja Aburto, Victor Hugo. Instituto Mexicano del Seguro Social; MéxicoFil: Burgmann, Heinz. Medical University Vienna; AustriaFil: Carratalà, Jordi. Universidad de Barcelona; España. Instituto de Investigación Biomédica de Bellvitge; España. Spanish Network for Research in Infectious Diseases; EspañaFil: Chowell, Gerardo. Georgia State University; Estados Unidos. National Institutes of Health; Estados UnidosFil: Cilloniz, Catia. Universidad de Barcelona; España. Instituto de Investigaciones Biomédicas August Pi i Sunyer; EspañaFil: Cohen, Jessica. Centers for Disease Control and Prevention; Estados UnidosFil: Cutter, Jeffery. Ministry of Health; SingapurFil: Filleul, Laurent. Santé publique; Francia. French National Public Health Agency; FranciaFil: Garg, Shikha. Centers for Disease Control and Prevention; Estados UnidosFil: Geis, Steffen. London School of Hygiene and Tropical Medicine; Reino UnidoFil: Helferty, Melissa. Public Health Agency; CanadáFil: Huang, Wan Ting. Taiwan Centers for Disease Control; ChinaFil: Jain, Seema. Centers for Disease Control and Prevention; Estados UnidosFil: Sevic, Biljana Joves. Institute for Pulmonary Diseases of Vojvodina; SerbiaFil: Kelly, Paul. Australian Capital Territory Health Directorate; Australia. Australian National University Medical School; AustraliaFil: Kusznierz, Gabriela. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorios e Instituto de Salud "Dr. C. G. Malbran". Instituto Nacional de Enfermedades Respiratorias; ArgentinaFil: Lehners, Nicola. Ruprecht Karls Universitat Heidelberg; AlemaniaFil: Lenzi, Luana. Universidade Federal do Paraná; BrasilFil: Ling, Ivan T.. Sir Charles Gairdner Hospital; AustraliaFil: Mitchell, Robyn. Public Health Agency; CanadáFil: Mulrennan, Siobhain A.. Sir Charles Gairdner Hospital; Canadá. University of Western Australia; AustraliaFil: Nishioka, Sergio A.. Ministerio de Salud de Brasil; BrasilFil: Norton, Robert. Townsville Hospital; AustraliaFil: Oh, Won Sup. Kangwon National University School of Medicine; Corea del SurFil: Orellano, Pablo Wenceslao. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Science and technology requirements to explore caves in our Solar System

Research on planetary caves requires cross-planetary-body investigations spanning multiple disciplines, including geology, climatology, astrobiology, robotics, human exploration and operations. The community determined that a roadmap was needed to establish a common framework for planetary cave research. This white paper is our initial conception

A Vision for Talca's Future: Post-Earthquake Reconstruction Redevelopment Studio

In September 2012, SERVIU, the regional arm of the Chilean Ministry of Hotusing and Urban Development (MINVU), tasked our program with evaluating and reassessing housing reconstruction efforts in Talca, the capital city of the Maule region, in the wake of the 2010 earthquake that affected the region. To carry out this task, we focused on a case study neighborhood in Talca’s historic center, Barrio Las Heras. This document provides the synthesis of fourteen weeks working on the project, including a presentation of the context, our assessment of the strengths and weaknesses of the reconstruction efforts to date, and recommendations for Talca’s future development