bluuebunny/crossref_metadata_2025_split huggingface dataset:
A brief survey of observers for disturbance estimation and compensation
Authors: Li Teng , Xing Hongjun , Hashemi Ehsan , Taghirad Hamid D. , Tavakoli Mahdi 
Published: September 2023

AbstractAn accurate dynamic model of a robot is fundamentally important for a control system, while uncertainties residing in the model are inevitable in a physical robot system. The uncertainties can be categorized as internal disturbances and external disturbances in general. The former may include dynamic model errors and joint frictions, while the latter may include external payloads or human-exerted force to the robot. Disturbance observer is an important technique to estimate and compensate for the uncertainties of the dynamic model. Different types of disturbance observers have been developed to estimate the lumped uncertainties so far. In this paper, we conducted a brief survey on five typical types of observers from a perspective of practical implementation in a robot control system, including generalized momentum observer (GMO), joint velocity observer (JVOB), nonlinear disturbance observer (NDOB), disturbance Kalman filter (DKF), and extended state observer (ESO). First, we introduced the basics of each observer including equations and derivations. Two common types of disturbances are considered as two scenarios,that is, constant external disturbance and time-varying external disturbance. Then, the observers are separately implemented in each of the two simulated scenarios, and the disturbance tracking performance of each observer is presented while their performance in the same scenario has also been compared in the same figure. Finally, the main features and possible behaviors of each type of observer are summarized and discussed. This survey is devoted to helping readers learn the basic expressions of five typical observers and implement them in a robot control system.
Health System Response to the 2023 Floods in Emilia-Romagna, Italy: A Field Report
Authors: Valente Martina , Zanellati Maicol , Facci Giulia , Zanna Nicola , Petrone Emilio , Moretti Erika , Barone-Adesi Francesco , Ragazzoni Luca 
Published: September 2023

AbstractIn May 2023, the Italian region Emilia-Romagna was hit by intense rainfall, which caused extensive floods in densely populated areas. On May 4, 2023, a 12-month state of emergency was declared in the region with the activation of response and recovery plans. This field report provides an overview of the health response to the floods, paying particular attention to the measures put in place to ensure care for displaced populations and raising interesting points of discussion regarding the role of the health system during extreme weather events (EWEs). The considerations that emerge from this report underline the need for a primary care approach to disasters, especially when these occur in areas with a high prevalence of elderly resident population, and underscore the importance of integration of different levels of care.
We need to talk about values: a proposed framework for the articulation of normative reasoning in health technology assessment
Authors: Charlton Victoria , DiStefano Michael , Mitchell Polly , Morrell Liz , Rand Leah , Badano Gabriele , Baker Rachel , Calnan Michael , Chalkidou Kalipso , Culyer Anthony , Howdon Daniel , Hughes Dyfrig , Lomas James , Max Catherine , McCabe Christopher , O'Mahony James F. , Paulden Mike , Pemberton-Whiteley Zack , Rid Annette , Scuffham Paul , Sculpher Mark , Shah Koonal , Weale Albert , Wester Gry 
Published: September 2023

AbstractIt is acknowledged that health technology assessment (HTA) is an inherently value-based activity that makes use of normative reasoning alongside empirical evidence. But the language used to conceptualise and articulate HTA's normative aspects is demonstrably unnuanced, imprecise, and inconsistently employed, undermining transparency and preventing proper scrutiny of the rationales on which decisions are based. This paper – developed through a cross-disciplinary collaboration of 24 researchers with expertise in healthcare priority-setting – seeks to address this problem by offering a clear definition of key terms and distinguishing between the types of normative commitment invoked during HTA, thus providing a novel conceptual framework for the articulation of reasoning. Through application to a hypothetical case, it is illustrated how this framework can operate as a practical tool through which HTA practitioners and policymakers can enhance the transparency and coherence of their decision-making, while enabling others to hold them more easily to account. The framework is offered as a starting point for further discussion amongst those with a desire to enhance the legitimacy and fairness of HTA by facilitating practical public reasoning, in which decisions are made on behalf of the public, in public view, through a chain of reasoning that withstands ethical scrutiny.
Mineral Prospectivity Mapping of Tungsten Polymetallic Deposits Using Machine Learning Algorithms and Comparison of Their Performance in the Gannan Region, China
Authors: Lou Yonghang , Liu Yue 
Published: September 2023

AbstractThe current study aims at assessing the capabilities of five machine learning models in terms of mapping tungsten polymetallic prospectivity in the Gannan region, China. The five models include logistic regression (LR), support vector machine (SVM), random forest, convolutional neural network (CNN), and light gradient boosting machine (LGBM) models. Three types of data sets including geochemical data, lithostratigraphic contacts, and faults were employed to generate 16 evidential maps that were used to build the machine learning models. Tungsten polymetallic deposits were randomly separated into two parts: 80% for training and 20% for validating. Performance of the models was evaluated through receiver operating characteristic and K‐fold cross validation, with an emphasis on the variable influence within different machine learning methods. The results show that the models are especially sensitive to the chemical elements: Be, Bi, Pb, and Cd, implying that they are closely related to tungsten polymetallic mineralization. Compared to other models, the LGBM and CNN models performed best, while the LR model was the most stable. The results also indicated that the CNN model can predict the maximum number of tungsten polymetallic deposits within the minimum area based on the prediction‐area plot analysis, while the SVM model can capture the least amount of tungsten polymetallic deposits within the largest area. Finally, 18 prospective areas were delineated according to the prediction results of the machine learning models, which provided important guidance for tungsten polymetallic exploration in the study area.
Chemical Oxygen Demand as a Measure of Fluvial Organic Matter Oxidation State
Authors: Worrall Fred , Clay Gareth D. , Howden Nicholas J. K. , Burt Tim P. 
Published: September 2023

AbstractThe oxidative ratio (OR) of the terrestrial biosphere is directly related to the size of the terrestrial biosphere carbon sink. In turn, OR of naturally occurring organic matter can be directly related to the oxidation state of the carbon in naturally occurring organic matter (Cox). Chemical oxygen demand (COD) is a widely measured water quality parameter that has been used as a short‐term substitute for the biochemical oxygen demand (BOD). Here, we propose that if the concentration of reduced species is known, then COD measurement can be used to assess the oxidation state (Cox) of fluvial organic C. Using a Bayesian hierarchical modeling approach, this study analyzed 21 years of water quality monitoring across England to calculate Cox of fluvial organic matter. The study showed that (a) COD could not be considered separately from the reduced species (e.g., NH4) commonly occurring in freshwater water samples, but it was still possible to calculate the Cox of dissolved organic carbon (DOC) and particulate organic carbon (POC). (b) The median Cox of DOC was 0.23 with a 95th percentile range of −0.1 to 0.4. (c) The median Cox of POC was 0.20 with a 95th percentile range of 0.03–0.37. (d) The estimated Cox in fluvial systems confirms that BOD is decoupled from the production of CO2. Including new Cox estimates in the global estimate of OR gives a new median value of 1.059 with a 95th percentile range of 1.047–1.071, giving the annual flux of CO2 to land (fland) of 1.45 ± 0.1 Gt C/year.
Seasonal Tropospheric Distribution and Air‐Sea Fluxes of Atmospheric Potential Oxygen From Global Airborne Observations
Authors: Jin Yuming , Stephens Britton B. , Keeling Ralph F. , Morgan Eric J. , Rödenbeck Christian , Patra Prabir K. , Long Matthew C. 
Published: September 2023

AbstractSeasonal change of atmospheric potential oxygen (APO ∼ O2 + CO2) is a tracer for air‐sea O2 flux with little sensitivity to the terrestrial exchange of O2 and CO2. In this study, we present the tropospheric distribution and inventory of APO in each hemisphere with seasonal resolution, using O2 and CO2 measurements from discrete airborne campaigns between 2009 and 2018. The airborne data are represented on a mass‐weighted isentropic coordinate (Mθe) as an alternative to latitude, which reduces the noise from synoptic variability in the APO cycles. We find a larger seasonal amplitude of APO inventory in the Southern Hemisphere relative to the Northern Hemisphere, and a larger amplitude in high latitudes (low Mθe) relative to low latitudes (high Mθe) within each hemisphere. With a box model, we invert the seasonal changes in APO inventory to yield estimates of air‐sea flux cycles at the hemispheric scale. We found a larger seasonal net outgassing of APO in the Southern Hemisphere (518 ± 52.6 Tmol) than in the Northern Hemisphere (342 ± 52.1 Tmol). Differences in APO phasing and amplitude between the hemispheres suggest distinct physical and biogeochemical mechanisms driving the air‐sea O2 fluxes, such as fall outgassing of photosynthetic O2 in the Northern Hemisphere, possibly associated with the formation of the seasonal subsurface shallow oxygen maximum. We compare our estimates with four model‐ and observation‐based products, identifying key limitations in these products or in the tools used to create them.
Dawn‐Dusk Asymmetry of Energetic Electron at LEO During a Storm: Observation by FY3E
Authors: Sun Yi‐Xin , Zong Qiu‐Gang , Liu Ying , Ye Yu‐Guang , Zou Hong , Yue Chao , Zhou Xu‐Zhi , Hao Yi‐Xin 
Published: September 2023

AbstractElectrons in Low Earth Orbit (LEO) have been a popular research topic since the early days of space exploration. However, due to the limited pitch angle coverage and energy resolution of past in‐situ measurements, there is still much to uncover about the radiation environment. Fortunately, the recently launched satellite FY3E, which is equipped with the Medium‐Energy Electron Detector, is changing this. FY3E is the world's first early‐morning‐orbit meteorological satellite for civil use. With the ability to provide full pitch angle coverage and discrete energy measurements of 30–600 keV electrons, we now have an unprecedented opportunity to investigate the dynamics of space radiation at LEO and Magnetosphere‐Ionosphere coupling. Using the newly available measurements, we have discovered that during storms, electron precipitation exhibits dawn‐dusk asymmetry up to 100 keV. At dawn sector downward electrons can be similar to trapped electrons, and the loss cone ratio (precipitating flux over trapped flux) can be as high as unity at L‐shell greater than 6. While at dusk barely precipitation can be seen. The flux of trapped, upward, downward and net precipitation are calculated, and separate energy flux spectra of downward, upward, and trapped electrons are presented for the first time. With significant upward electrons up to 200 keV, asymmetric local pitch angle is observed at dawn within intense precipitation. In light of these findings, FY3E reveals critical information for understanding the Magnetosphere‐Ionosphere Coupling process.
Garnet microstructures suggest ultra-fast decompression of ultrahigh-pressure rocks
Authors: Luisier Cindy , Tajčmanová Lucie , Yamato Philippe , Duretz Thibault 
Published: September 2023

AbstractPlate tectonics is a key driver of many natural phenomena occurring on Earth, such as mountain building, climate evolution and natural disasters. How plate tectonics has evolved through time is still one of the fundamental questions in Earth sciences. Natural microstructures observed in exhumed ultrahigh-pressure rocks formed during continental collision provide crucial insights into tectonic processes in the Earth’s interior. Here, we show that radial cracks around SiO2 inclusions in ultrahigh-pressure garnets are caused by ultrafast decompression. Decompression rates of at least 8 GPa/Myr are inferred independently of current petrochronological estimates by using thermo-mechanical numerical modeling. Our results question the traditional interpretation of fast and significant vertical displacement of ultrahigh-pressure tectonic units during exhumation. Instead, we propose that such substantial decompression rates are related to abrupt changes in the stress state of the lithosphere independently of the spatial displacement.
Drainage explains soil liquefaction beyond the earthquake near-field
Authors: Ben-Zeev Shahar , Goren Liran , Toussaint Renaud , Aharonov Einat 
Published: September 2023

AbstractEarthquake-induced soil-liquefaction is a devastating phenomenon associated with loss of soil rigidity due to seismic shaking, resulting in catastrophic liquid-like soil deformation. Traditionally, liquefaction is viewed as an effectively undrained process. However, since undrained liquefaction only initiates under high energy density, most earthquake liquefaction events remain unexplained, since they initiate far from the earthquake epicenter, under low energy density. Here we show that liquefaction can occur under drained conditions at remarkably low seismic-energy density, offering a general explanation for earthquake far-field liquefaction. Drained conditions promote interstitial fluid flow across the soil during earthquakes, leading to excess pore pressure gradients and loss of soil strength. Drained liquefaction is triggered rapidly and controlled by a propagating compaction front, whose velocity depends on the seismic-energy injection rate. Our findings highlight the importance of considering soil liquefaction under a spectrum of drainage conditions, with critical implications for liquefaction potential assessments and hazards.
FEAST: A flow cytometry-based toolkit for interrogating microglial engulfment of synaptic and myelin proteins
Authors: Dissing-Olesen Lasse , Walker Alec J. , Feng Qian , Barr Helena J. , Walker Alicia C. , Xie Lili , Wilton Daniel K. , Das Indrani , Benowitz Larry I. , Stevens Beth 
Published: September 2023

AbstractAlthough engulfment is a hallmark of microglia function, fully validated platforms that facilitate high-throughput quantification of this process are lacking. Here, we present FEAST (Flow cytometric Engulfment Assay for Specific Target proteins), which enables interrogation of in vivo engulfment of synaptic material by brain resident macrophages at single-cell resolution. We optimize FEAST for two different analyses: quantification of fluorescent material inside live cells and of engulfed endogenous proteins within fixed cells. To overcome false-positive engulfment signals, we introduce an approach suitable for interrogating engulfment in microglia from perfusion-fixed tissue. As a proof-of-concept for the specificity and versatility of FEAST, we examine the engulfment of synaptic proteins after optic nerve crush and of myelin in two mouse models of demyelination (treatment with cuprizone and injections of lysolecithin). We find that microglia, but not brain-border associated macrophages, engulf in these contexts. Our work underscores how FEAST can be utilized to gain critical insight into functional neuro-immune interactions that shape development, homeostasis, and disease.
Lung extracellular matrix modulates KRT5+ basal cell activity in pulmonary fibrosis
Authors: Hewitt Richard J. , Puttur Franz , Gaboriau David C. A. , Fercoq Frédéric , Fresquet Maryline , Traves William J. , Yates Laura L. , Walker Simone A. , Molyneaux Philip L. , Kemp Samuel V. , Nicholson Andrew G. , Rice Alexandra , Roberts Edward , Lennon Rachel , Carlin Leo M. , Byrne Adam J. , Maher Toby M. , Lloyd Clare M. 
Published: September 2023

AbstractAberrant expansion of KRT5+ basal cells in the distal lung accompanies progressive alveolar epithelial cell loss and tissue remodelling during fibrogenesis in idiopathic pulmonary fibrosis (IPF). The mechanisms determining activity of KRT5+ cells in IPF have not been delineated. Here, we reveal a potential mechanism by which KRT5+ cells migrate within the fibrotic lung, navigating regional differences in collagen topography. In vitro, KRT5+ cell migratory characteristics and expression of remodelling genes are modulated by extracellular matrix (ECM) composition and organisation. Mass spectrometry- based proteomics revealed compositional differences in ECM components secreted by primary human lung fibroblasts (HLF) from IPF patients compared to controls. Over-expression of ECM glycoprotein, Secreted Protein Acidic and Cysteine Rich (SPARC) in the IPF HLF matrix restricts KRT5+ cell migration in vitro. Together, our findings demonstrate how changes to the ECM in IPF directly influence KRT5+ cell behaviour and function contributing to remodelling events in the fibrotic niche.
Embedded shape morphing for morphologically adaptive robots
Authors: Sun Jiefeng , Lerner Elisha , Tighe Brandon , Middlemist Clint , Zhao Jianguo 
Published: September 2023

AbstractShape-morphing robots can change their morphology to fulfill different tasks in varying environments, but existing shape-morphing capability is not embedded in a robot’s body, requiring bulky supporting equipment. Here, we report an embedded shape-morphing scheme with the shape actuation, sensing, and locking, all embedded in a robot’s body. We showcase this embedded scheme using three morphing robotic systems: 1) self-sensing shape-morphing grippers that can adapt to objects for adaptive grasping; 2) a quadrupedal robot that can morph its body shape for different terrestrial locomotion modes (walk, crawl, or horizontal climb); 3) an untethered robot that can morph its limbs’ shape for amphibious locomotion. We also create a library of embedded morphing modules to demonstrate the versatile programmable shapes (e.g., torsion, 3D bending, surface morphing, etc.). Our embedded morphing scheme offers a promising avenue for robots to reconfigure their morphology in an embedded manner that can adapt to different environments on demand.
Solar-driven upgrading of biomass by coupled hydrogenation using in situ (photo)electrochemically generated H2
Authors: Obata Keisuke , Schwarze Michael , Thiel Tabea A. , Zhang Xinyi , Radhakrishnan Babu , Ahmet Ibbi Y. , van de Krol Roel , Schomäcker Reinhard , Abdi Fatwa F. 
Published: September 2023

AbstractWith the increasing pressure to decarbonize our society, green hydrogen has been identified as a key element in a future fossil fuel-free energy infrastructure. Solar water splitting through photoelectrochemical approaches is an elegant way to produce green hydrogen, but for low-value products like hydrogen, photoelectrochemical production pathways are difficult to be made economically competitive. A possible solution is to co-produce value-added chemicals. Here, we propose and demonstrate the in situ use of (photo)electrochemically generated H2 for the homogeneous hydrogenation of itaconic acid—a biomass-derived feedstock—to methyl succinic acid. Coupling these two processes offers major advantages in terms of stability and reaction flexibility compared to direct electrochemical hydrogenation, while minimizing the overpotential. An overall conversion of up to ~60% of the produced hydrogen is demonstrated for our coupled process, and a techno-economic assessment of our proposed device further reveals the benefit of coupling solar hydrogen production to a chemical transformation.
Encoding multistate charge order and chirality in endotaxial heterostructures
Authors: Husremović Samra , Goodge Berit H. , Erodici Matthew P. , Inzani Katherine , Mier Alberto , Ribet Stephanie M. , Bustillo Karen C. , Taniguchi Takashi , Watanabe Kenji , Ophus Colin , Griffin Sinéad M. , Bediako D. Kwabena 
Published: September 2023

AbstractHigh-density phase change memory (PCM) storage is proposed for materials with multiple intermediate resistance states, which have been observed in 1T-TaS2 due to charge density wave (CDW) phase transitions. However, the metastability responsible for this behavior makes the presence of multistate switching unpredictable in TaS2 devices. Here, we demonstrate the fabrication of nanothick verti-lateral H-TaS2/1T-TaS2 heterostructures in which the number of endotaxial metallic H-TaS2 monolayers dictates the number of resistance transitions in 1T-TaS2 lamellae near room temperature. Further, we also observe optically active heterochirality in the CDW superlattice structure, which is modulated in concert with the resistivity steps, and we show how strain engineering can be used to nucleate these polytype conversions. This work positions the principle of endotaxial heterostructures as a promising conceptual framework for reliable, non-volatile, and multi-level switching of structure, chirality, and resistance.
Seasonal advance of intense tropical cyclones in a warming climate
Authors: Shan Kaiyue , Lin Yanluan , Chu Pao-Shin , Yu Xiping , Song Fengfei 
Published: September 2023

Abstract
Intense tropical cyclones (TCs), which often peak in autumn1,2, have destructive impacts on life and property3–5, making it crucial to determine whether any changes in intense TCs are likely to occur. Here, we identify a significant seasonal advance of intense TCs since the 1980s in most tropical oceans, with earlier-shifting rates of 3.7 and 3.2 days per decade for the Northern and Southern Hemispheres, respectively. This seasonal advance of intense TCs is closely related to the seasonal advance of rapid intensification events, favoured by the observed earlier onset of favourable oceanic conditions. Using simulations from multiple global climate models, large ensembles and individual forcing experiments, the earlier onset of favourable oceanic conditions is detectable and primarily driven by greenhouse gas forcing. The seasonal advance of intense TCs will increase the likelihood of intersecting with other extreme rainfall events, which usually peak in summer6,7, thereby leading to disproportionate impacts.