bluuebunny/crossref_metadata_2025_split huggingface dataset:
A generalised force equivalence-based modelling method for a dry wind-tunnel flutter test system
Authors: Zhang Z. , Gao B. , Wang J. , Xu D. , Chen G. , Yao W. 
Published: March 2021

ABSTRACTDry wind-tunnel (DWT) flutter test systems model the unsteady distributed aerodynamic force using various electromagnetic exciters. They can be used to test the aeroelastic and aeroservoelastic stability of smart aircraft or high-speed flight vehicles. A new parameterised modelling method at the full system level based on the generalised force equivalence for DWT flutter systems is proposed herein. The full system model includes the structural dynamic model, electromechanical coupling model and fast aerodynamic computation model. An optimisation search method is applied to determine the best locations for measurement and excitation by introducing Fisher’s information matrix. The feasibility and accuracy of the proposed system-level numerical DWT modelling method have been validated for a plate aeroelastic model with four exciters/transducers. The effects of key parameters including the number of exciters, the control time delay, the noise interference and the electrical parameters of the electromagnetic exciter model have also been investigated. The numerical and experimental results indicate that the proposed modelling method achieves good accuracy (with deviations of less than 1.5% from simulations and 4.5% from experimental test results for the flutter speed) and robust performance even in uncertain environments with a 10% noise level.
Extending tamely ramified strict 1-motives into két log 1-motives
Authors: Zhao Heer 
Published: March 2021

AbstractWe define két abelian schemes, két 1-motives and két log 1-motives and formulate duality theory for these objects. Then we show that tamely ramified strict 1-motives over a discrete valuation field can be extended uniquely to két log 1-motives over the corresponding discrete valuation ring. As an application, we present a proof to a result of Kato stated in [12, §4.3] without proof. To a tamely ramified strict 1-motive over a discrete valuation field, we associate a monodromy pairing and compare it with Raynaud’s geometric monodromy.
Feasibility of ultraviolet light-emitting diode irradiation robot for terminal decontamination of coronavirus disease 2019 (COVID-19) patient rooms
Authors: Choi Hee Kyoung , Cui Chunguang , Seok Hyeri , Bae Joon-Yong , Jeon Ji Hoon , Lee Gee Eun , Choi Won Suk , Park Man-Seong , Park Dae Won 
Published: March 2021

AbstractObjective:To investigate the feasibility of using an ultraviolet light-emitting diode (UV LED) robot for the terminal decontamination of coronavirus disease 2019 (COVID-19) patient rooms.Methods:We assessed the presence of viral RNA in samples from environmental surfaces before and after UV LED irradiation in COVID-19 patient rooms after patient discharge.Results:We analyzed 216 environmental samples from 17 rooms: 2 from airborne infection isolation rooms (AIIRs) in the intensive care unit (ICU) and 15 from isolation rooms in the community treatment center (CTC). Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA was detected in 40 (18.5%) of 216 samples after patient discharge: 12 (33.3%) of 36 samples from AIIRs in the ICU, and 28 (15.6%) of 180 samples from isolation rooms in the CTC. In 1 AIIR, all samples were PCR negative after UV LED irradiation. In the CTC rooms, 14 (8.6%) of the 163 samples were PCR positive after UV LED irradiation. However, viable virus was not recovered from the culture of any of the PCR-positive samples.Conclusions:Although no viable virus was recovered, SARS-CoV-2 RNA was detected on various environmental surfaces. The use of a UV LED disinfection robot was effective in spacious areas such as an ICU, but its effects varied in small spaces like CTC rooms. These findings suggest that the UV LED robot may need enough space to disinfect rooms without recontamination by machine wheels or insufficient disinfection by shadowing.
A theory of glacier dynamics and instabilities Part 1: Topographically confined glaciers
Authors: Ou Hsien-Wang 
Published: March 2021

AbstractWe present a theoretical framework that integrates the dynamics of glaciers with and without the topographic confinement. This Part 1 paper concerns the former, which may exhibit surge cycles when subjected to thermal switches associated with the bed condition. With the topographic trough setting the glacier width and curbing the lateral drainage of the meltwater, the problem falls under the purview of the undrained plastic bed (UPB) formalism. Employing the UPB, we shall examine the external controls of the glacial behavior and test them against observations. Through our non-dimensionalization scheme, we construct a 2-D regime diagram, which allows a ready prognosis of the glacial properties over the full range of the external conditions, both climate- and size-related. We first discern the boundaries separating the glacial regimes of steady-creep, cyclic-surging and steady-sliding. We then apply the regime diagram to observed glaciers for quantitative comparisons. These include the Svalbard glaciers of both normal and surge types, Northeast Greenland Ice Stream characterized by steady-sliding, and Hudson Strait Ice Stream exhibiting cyclic surges. The quantitative validation of our model containing no free parameters suggests that the thermal switch may unify the dynamics of these diverse glaciers.
Nonignorable Attrition in Pairwise Randomized Experiments
Authors: Fukumoto Kentaro 
Published: March 2021

AbstractIn pairwise randomized experiments, what if the outcomes of some units are missing? One solution is to delete missing units (the unitwise deletion estimator, UDE). If attrition is nonignorable, however, the UDE is biased. Instead, scholars might employ the pairwise deletion estimator (PDE), which deletes the pairmates of missing units as well. This study proves that the PDE can be biased but more efficient than the UDE and, surprisingly, the conventional variance estimator of the PDE is unbiased in a super-population. I also propose a new variance estimator for the UDE and argue that it is easier to interpret the PDE as a causal effect than the UDE. To conclude, I recommend the PDE rather than the UDE.
Lagged Outcomes, Lagged Predictors, and Lagged Errors: A Clarification on Common Factors
Authors: Cook Scott J. , Webb Clayton 
Published: March 2021

AbstractDebate on the use of lagged dependent variables has a long history in political science. The latest contribution to this discussion is Wilkins (2018, Political Science Research and Methods, 6, 393–411), which advocates the use of an ADL(2,1) model when there is serial dependence in the outcome and disturbance. While this specification does offer some insurance against serially correlated disturbances, this is never the best (linear unbiased estimator) approach and should not be pursued as a general strategy. First, this strategy is only appropriate when the data-generating process (DGP) actually implies a more parsimonious model. Second, when this is not the DGP—e.g., lags of the predictors have independent effects—this strategy mischaracterizes the dynamic process. We clarify this issue and detail a Wald test that can be used to evaluate the appropriateness of the Wilkins approach. In general, we argue that researchers need to always: (i) ensure models are dynamically complete and (ii) test whether more restrictive models are appropriate.
Strategic government communication about performance
Authors: de Benedictis-Kessner Justin 
Published: March 2021

AbstractA great deal of research presents the correspondence between economic conditions and incumbent electoral fortunes as evidence of democratic accountability. A central theoretical mechanism for this phenomenon is that voters have information about performance. Using communications data consisting of more than 110,000 government press releases from cities in the US combined with fine-grained economic and crime data, I leverage the breadth of local variation in conditions to assess the inputs to this mechanism behind accountability. I provide causal evidence that government communication changes as a result of performance in a strategic manner: local politicians are more likely to communicate about both economic conditions and crime when performance is improving—better wages and less crime—than when performance is worse. These findings add direct evidence from the underutilized area of local politics that politicians strategically communicate in a way that threatens accountability.
COMPARISON OF THERMAL DECOMPOSITION AND SEQUENTIAL DISSOLUTION—TWO SAMPLE PREPARATION METHODS FOR RADIOCARBON DATING OF LIME MORTARS
Authors: Daugbjerg Thomas Schrøder , Lindroos Alf , Hajdas Irka , Ringbom Åsa , Olsen Jesper 
Published: March 2021

ABSTRACTDating lime mortar samples using the radiocarbon (14C) method can be difficult. This is because the contamination is similar to the primary dating material (CaCO3) and consequently difficult to remove. Mortar can also have late-in-formation pyrogenic carbonate from interactions with the environment after the initial hardening phase, such as recrystallization, fire damage or delayed hardening. When 14C dating a system of primary dating material, contamination and late-in-formation pyrogenic carbonate, one approach is multi-fraction dating with conclusiveness criteria. If a sample has sufficient contamination or late-in-formation pyrogenic carbonate, the criteria evaluate the result inconclusive. To improve inconclusive results from such samples, this study investigates sample preparation by thermal decomposition. Here samples that were inconclusively dated by the authors’ traditional method, sequential dissolution with 85% phosphoric acid, are investigated further. This study finds that CO2 thermally decomposed at low temperatures contains some late-in-formation pyrogenic carbonate. By rejecting CO2 decomposed at low temperatures, Kastelholm castle and Kimito church in Finland are conclusively and accurately dated. Furthermore, a preheating method removes some late-in-formation carbonate, but not enough for a conclusive result. Finally, thermal decomposition finds difficulty in discerning binder carbonate from limestone and marble contamination.
“To Wage a War”: Crime, Race, and State Making in the Age of FDR
Authors: Denney Matthew G. T. 
Published: March 2021

AbstractThe FDR administration waged a war on crime starting in 1933. I argue that this war on crime had three primary effects. First, it created a ratchet effect whereby expanded institutions did not return to previous levels after the campaign ended. Second, it instilled enduring institutional and racial logics into law enforcement in America. By building a state through a war on crime, these leaders constructed a criminal justice system designed to make war. Moreover, they perpetuated the surveillance of Black leaders and eschewed calls from Black organizations demanding protection from widespread racial violence. Third, these political entrepreneurs induced an issue realignment that defined crime policy around a politics of consensus—a consensus that included every major political bloc but Black Americans, who unsuccesfully called on the federal government to hold local police accountable and address racial inequality. This coalition diffused their methods to states and deployed future wars on crime, and the racial logics cemented in the FDR era set the stage for these future wars to be deployed disproportionately against the Black community.
A proof of a conjecture of Gyárfás, Lehel, Sárközy and Schelp on Berge-cycles
Authors: Omidi G. R. 
Published: March 2021

AbstractIt has been conjectured that, for any fixed \[{\text{r}} \geqslant 2\] and sufficiently large n, there is a monochromatic Hamiltonian Berge-cycle in every \[({\text{r}} - 1)\]-colouring of the edges of \[{\text{K}}_{\text{n}}^{\text{r}}\], the complete r-uniform hypergraph on n vertices. In this paper we prove this conjecture.
Bronchogenic cyst presenting with respiratory distress in a neonate
Authors: Diraneyya Obayda M. , Al-Mutrafi Amna , Al Jadaan Saud , Eldadah Osama , Alghamdi Mohammed H. , Alghamdi Abdullah A. , Alhabshan Fahad 
Published: March 2021

AbstractBronchogenic cysts are considered rare airway anomalies that can have a significant impact on the well-being of infants. In this case report, we present a rare presentation of bronchogenic cyst presenting with early neonatal respiratory distress due to airway and vascular compression. Surgical excision was curative with an excellent prognosis.
Integrated PET-CT treatment planning of locally advanced head and neck cancer: a review of imaging features and the contribution to clinical outcomes
Authors: Ampil Federico , Norton Michelle 
Published: March 2021

AbstractAim:Little is known about how integrated positron emission tomography-computed tomography (IPET-CT), both imaging tools and not methods of treatment, contributes to head and neck cancer patients’ outcomes. We analysed the clinical PET-CT findings and their correlation to the effects of applied contemporary disease management.Methodology:A retrospective analysis of 29 individuals who underwent treatment planning fusion of PET-CT for radiochemotherapy of locally advanced head and neck cancer between 2010 and 2016 was undertaken. Gross tumour volumes were categorised as small (≤36 cm3) or large (>36 cm3), and tumour responses to therapy were classified as complete or incomplete.Results:The overall rates of complete tumour response (CTR), 3-year crude survival and failure (all types included) were 80%, 41% and 55%, respectively. Comparative analysis of tumour volume subsets revealed no significant differences in the rates of CTR (p > 0.80), 3-year survival (p > 0.30) and locoregional recurrence (p > 0.70). CTR was associated with improved prognosis (p > 0.05) and fewer tumour relapses (p < 0.02).Conclusion:Our findings, although not truly conclusive, appear in line with those in the literature. Smaller tumour volumes and CTRs shown on integrated PET-CT are likely to play important roles in the promotion of better prognosis, but further study with larger patient numbers and more data are needed.
To segment or not to segment the PTV in SIB-VMAT of head-and-neck cancer: a dosimetric comparison with relevance to clinical practice
Authors: Mathew Manu , Godson Henry F. , Thomas Abel J. , Balu Krishna Sasidharan , Kumar A Sathish , Isiah Rajesh , John Subhashini , Pavamani Simon P. 
Published: March 2021

AbstractAim:This study aimed to evaluate and compare simultaneous integrated boost-based volumetric modulated arc therapy (SIB-VMAT) of head-and-neck plans optimised using segmented and non-segmented intermediate-risk target volumes.Materials and methods:CT data of 20 patients with locally advanced laryngeal cancer treated with radical chemoradiation were included retrospectively. Both segmented [planning target volume (PTV) IR!] and non-segmented PTV (PTV IR) volumes were created for the intermediate-risk volume. Correspondingly, two VMAT plans were generated for every CT dataset. Dosimetry parameters obtained from cumulative dose volume histogram and the quality indices such as conformity and homogeneity indices were evaluated for both plans and were statistically analysed.Results:Maximum dose of PTV IR! was observed to be higher in the non-segmented plans (7281·45 versus 7075·75 cGy) and was statistically significant (p = 0·002). Homogeneity index (HI) of PTV IR! in segmented plans fared better compared to non-segmented plans (0·1 versus 0·12, p = 0·01). All other dosimetry parameters were found to be similar in both plans.Conclusion:This study shows that using segmented volumes for planning will lead to more homogenous plans with regard to intermediate- and low-risk volumes, especially under controlled settings.
Sustainable and equitable agricultural mechanization? A gendered perspective on maize shelling
Authors: Fischer Gundula , Kotu Bekele , Mutungi Christopher 
Published: March 2021

AbstractHow can agricultural mechanization be accomplished in a sustainable and equitable way? This question has gained increased prominence in mechanization research over the past few years. In this study, we apply the question to mechanized maize shelling in Tanzania as a case in point. Data from a survey with 400 farmers and from semi-structured interviews with 21 key informants are combined for a gender analysis that relies on Kabeer's concept of four institutional sites (household, community, market and government). The findings reveal that although mechanization reduces men's and women's perceived drudgery of shelling, relief depends on gendered patterns of labor allocation and decision-making at the household level. As a result, the transformation of inequitable norms emerges as paramount. Key informants identified additional aspects that would make mechanized shelling more equitable and sustainable, such as mainstreaming gender and mechanization in comprehensive agricultural training, or the sensitization of mechanized input suppliers and manufacturers to farmers' preferences (including gender-sensitive machine design). Concerted efforts in multiple institutional sites are needed to achieve lasting change in respect of equity in mechanization.
Constraining the Volume of Earth's Early Oceans With a Temperature‐Dependent Mantle Water Storage Capacity Model
Authors: Dong Junjie , Fischer Rebecca A. , Stixrude Lars P. , Lithgow‐Bertelloni Carolina R. 
Published: March 2021

AbstractThe water content in Earth's mantle today remains poorly constrained, but the bulk water storage capacity in the solid mantle can be quantified based on experimental data and may amount to a few times the modern surface ocean mass (OM). An appreciation of the mantle water storage capacity is indispensable to our understanding of how water may have cycled between the surface and mantle reservoirs and changed the volume of the oceans through time. In this study, we parameterized high pressure‐temperature experimental data on water storage capacities in major rock‐forming minerals to track the bulk water storage capacity in Earth's solid mantle as a function of temperature. We find that the mantle water storage capacity decreases as mantle potential temperature (Tp) increases, and its estimated value depends on the water storage capacity of bridgmanite in the lower mantle: 1.86–4.41 OM with a median of 2.29 OM for today (Tp = 1600 K), and 0.52–1.69 OM with a median of 0.72 OM for the early Earth's solid mantle (for a Tp that was 300 K higher). An increase in Tp by 200–300 K results in a decrease in the mantle water storage capacity by – OM. We explored how the volume of early oceans may have controlled sea level during the early Archean (4–3.2 Ga) with some additional assumptions about early continents. We found that more voluminous surface oceans might have existed if the actual mantle water content today is > 0.3–0.8 OM and the early Archean Tp was ≥1900 K.
The Growth of Europa's Icy Shell: Convection and Crystallization
Authors: Green A. P. , Montesi L. G. J. , Cooper C. M. 
Published: March 2021

AbstractThe thickness of Europa's icy shell, which controls its thermal and rheological structure, cannot currently be directly measured. However, it can be estimated through indirect methods, including geodynamic modeling. We simulate the crystallization of the ice shell from a liquid water ocean and its subsequent thermal equilibration in the presence of tidal heat. We evaluate the effects of solid‐state stagnant lid convection on the shell's thermal equilibrium thickness and shell formation timing. The thermal equilibrium thickness of the ice shell ranges from 5 to 30 km, depending on the imposed tidal flexure strain rate. The ice lithospheric thickness remains less than 8 km, independently of imposed tidal flexure strain rate, overall shell thickness, and surface temperature, suggesting the Europan ice lithospheric strength is globally uniform. Thermal convection significantly reduces the thermal equilibration time scale, with the Europan ice shell able to fully crystallize out from a liquid water ocean in less than 2 Myr. Heterogeneous thermal equilibrium thickness values across the satellite suggest that widespread crystallization and melting may occur at the base of the shell. Rapid melting and crystallization timing suggest that the young surface age of the Europan ice shell may be the result of rapid catastrophic whole‐shell melting and recrystallization entirely recycling the surface.
USP34 regulates tooth root morphogenesis by stabilizing NFIC
Authors: Jiang Shuang , Sheng Rui , Qi Xingying , Wang Jun , Guo Yuchen , Yuan Quan 
Published: March 2021

AbstractTooth root morphogenesis involves two biological processes, root elongation and dentinogenesis, which are guaranteed by downgrowth of Hertwig’s epithelial root sheath (HERS) and normal odontoblast differentiation. Ubiquitin-dependent protein degradation has been reported to precisely regulate various physiological processes, while its role in tooth development is still elusive. Here we show ubiquitin-specific protease 34 (USP34) plays a pivotal role in root formation. Deletion ofUsp34in dental mesenchymal cells leads to short root anomaly, characterized by truncated roots and thin root dentin. TheUSP34-deficient dental pulp cells (DPCs) exhibit decreased odontogenic differentiation with downregulation of nuclear factor I/C (NFIC). Overexpression of NFIC partially restores the impaired odontogenic potential of DPCs. These findings indicate that USP34-dependent deubiquitination is critical for root morphogenesis by stabilizing NFIC.
Identification of an intraocular microbiota
Authors: Deng Yuhua , Ge Xiaofei , Li Yan , Zou Bin , Wen Xiaofeng , Chen Weirong , Lu Lin , Zhang Meifen , Zhang Xiaomin , Li Chunmei , Zhao Chan , Lin Xiaofeng , Zhang Xiulan , Huang Xinhua , Li Xiaorong , Jin Ming , Peng Guang-Hua , Wang Dongni , Wang Xun , Lai Weiyi , Liang Juanran , Li Jing Jing , Liang Qiaoxing , Yang Liu , Zhang Qinfen , Li Yinyin , Lu Ping , Hu Xiao , Li Xifang , Deng Xiuli , Liu Yu , Zou Yanli , Guo Shixin , Chen Tingting , Qin Yali , Yang Fuhua , Miao Li , Chen Wei , Chan Chi-Chao , Lin Haotian , Liu Yizhi , Lee Richard W. J. , Wei Lai 
Published: March 2021

AbstractThe current dogma in ophthalmology and vision research presumes the intraocular environment to be sterile. However, recent evidence of intestinal bacterial translocation into the bloodstream and many other internal organs including the eyes, found in healthy and diseased animal models, suggests that the intraocular cavity may also be inhabited by a microbial community. Here, we tested intraocular samples from over 1000 human eyes. Using quantitative PCR, negative staining transmission electron microscopy, direct culture, and high-throughput sequencing technologies, we demonstrated the presence of intraocular bacteria. The possibility that the microbiome from these low-biomass communities could be a contamination from other tissues and reagents was carefully evaluated and excluded. We also provide preliminary evidence that a disease-specific microbial signature characterized the intraocular environment of patients with age-related macular degeneration and glaucoma, suggesting that either spontaneous or pathogenic bacterial translocation may be associated with these common sight-threatening conditions. Furthermore, we revealed the presence of an intraocular microbiome in normal eyes from non-human mammals and demonstrated that this varied across species (rat, rabbit, pig, and macaque) and was established after birth. These findings represent the first-ever evidence of intraocular microbiota in humans.