bluuebunny/crossref_metadata_2025_split huggingface dataset:
Celiac disease and risk of microscopic colitis: A nationwide population‐based matched cohort study
Authors: Bergman David , Khalili Hamed , Lebwohl Benjamin , Roelstraete Bjorn , Green Peter H. R. , Ludvigsson Jonas F. 
Published: March 2023

AbstractBackgroundAn association has been reported between celiac disease (CD) and microscopic colitis (MC). However, large, population‐based cohort studies are rare.ObjectiveTo systematically examine the association between CD and MC in a large, nationwide cohort.MethodsWe conducted a nationwide population‐based matched cohort study in Sweden of 45,138 patients with biopsy‐verified CD (diagnosed in 1990–2016), 223,149 reference individuals, and 51,449 siblings of CD patients. Data on CD and MC were obtained from all (n = 28) pathology departments in Sweden. Adjusted hazard ratios (aHRs) were calculated using Cox regression.ResultsDuring follow‐up, 452 CD patients and 197 reference individuals received an MC diagnosis (86.1 vs. 7.5 per 100,000 person‐years). This difference corresponded to an aHR of 11.6 (95% confidence interval [CI] = 9.8–13.8) or eight extra MC cases in 1000 CD patients followed up for 10 years. Although the risk of MC was highest during the first year of follow‐up (aHR 35.2; 95% CI = 20.1–61.6), it remained elevated even after 10 years (aHR 8.1; 95% CI = 6.0–10.9). Examining MC subtypes lymphocytic colitis (LC) and collagenous colitis (CC) separately, the aHR was 12.4 (95% CI = 10.0–15.3) for LC and 10.2 (95% CI = 7.7–13.6) for CC. MC was also more common before CD (adjusted odds ratio [aOR] = 52.7; 95% CI = 31.4–88.4). Compared to siblings, risk estimates decreased but remained elevated (CD and later MC: HR = 6.2; CD and earlier MC: aOR = 7.9).ConclusionOur study demonstrated a very strong association of MC with CD with an increased risk of future and previous MC in CD patients. The magnitude of the associations underscores the need to consider the concomitance of these diagnoses in cases in which gastrointestinal symptoms persist or recur despite a gluten‐free diet or conventional MC treatment. The comparatively lower risk estimates in sibling comparisons suggest that shared genetic and early environmental factors may contribute to the association between CD and MC.
Longitudinal study of antimicrobial use patterns, vaccination and disease prevalence in British sheep flocks
Authors: Davies Peers L. , Hyde Robert M. , Lovatt Fiona M. 
Published: March 2023

AbstractBackgroundThe aim of the study was to describe the longitudinal dynamics of antimicrobial use (AMU) on sheep farms and explore associations between AMU and management factors, vaccination strategies, reproductive performance and prevalence of lameness.MethodsAntimicrobial supply data were collected for 272 British sheep farms for 3–6 consecutive years between 2015 and 2021. These data were obtained from the farms' veterinary practices.ResultsAnnual median AMU ranged from 8.1 to 11.8 mg/kg population corrected unit. AMU was skewed in each year with a small proportion of very high users. AMU within farms varied substantially between years. High AMU farms in 1 year were not necessarily high in other years. No associations between AMU and either vaccine usage or lameness prevalence were found.LimitationsThe study design requires veterinarians and farmers to volunteer their data. This unavoidably introduces the potential for a participation bias.ConclusionsAMU on sheep farms is generally low, with a small number of farms being responsible for high usage. Targeting antimicrobial stewardship effort towards the small minority of persistently high users may be more appropriate than a focus on generic, industry‐wide attempts to reduce overall AMU.
On K3-fibred LARGE Volume Scenario with de Sitter vacua from anti-D3-branes
Authors: AbdusSalam Shehu , Crinò Chiara , Shukla Pramod 
Published: March 2023

Abstract
In the context of type IIB superstring compactifications on K3-fibred (weak) Swiss-cheese Calabi Yau (CY) orientifolds, we consider the realisation of de Sitter vacua obtained through the introduction of an $$ \overline{D3} $$

D
3

¯

-brane at the tip of a highly warped throat of Klebanov-Strassler type. Aiming to have a concrete global realisation, we perform a systematic search for the CY threefolds with 2 < h1,1< 5 arising from the Kreuzer-Skarke database, which satisfy the minimal requirements of being K3-fibred and suitable for moduli stabilisation within the LARGE Volume Scenario (LVS). In this context, after scanning the set of K3-fibred CY threefolds with a so-called diagonal del-Pezzo divisor needed for LVS, we realise that one of the main challenging requirements for having $$ \overline{D3} $$

D
3

¯

-brane uplifting is to find a suitable orientifold involution which can simultaneously result in a sufficient large D3 tadpole charge along with the presence of suitable O3-planes. In our detailed analysis (limited to) using the CY threefolds with small h1,1, we observe that these topological requirements rule out most of the CY geometries leading to only few possibly suitable candidates for the purpose of $$ \overline{D3} $$

D
3

¯

-brane uplifting. Subsequently, we present a global model using one such explicit K3-fibred CY threefold with h1,1 = 4 in which all the moduli can be consistently stabilised in a de Sitter minimum of the scalar potential.
Komplikationen und deren Behandlung nach PAO
Authors: Nonnenmacher Lars , Zimmerer Alexander , Hofer André , Bohorc Manuela , Matziolis Georg , Wassilew Georgi 
Published: March 2023

Zusammenfassung
Hintergrund
Die Hüftdysplasie stellt die häufigste Ursache der sekundären Koxarthrose dar. Die periazetabuläre Osteotomie (PAO) nach Ganz ist ein etabliertes Therapieverfahren, welches eine reproduzierbare Korrektur der dreidimensionalen Pathologie erlaubt. Den mittel- und langfristigen guten Behandlungsergebnissen stehen potenzielle Komplikationsrisiken eines invasiven Beckeneingriffes gegenüber. In Anbetracht des vornehmlich jungen Alters der Patient*innen ist eine Kenntnis der möglichen Komplikationen und der daraus resultierenden adäquaten Therapie wichtig.

Therapieentwicklung
Die kontinuierliche Weiterentwicklung der Operationstechnik und die zunehmende Erfahrung der Operateur*innen – mit dem sich hieraus ergebenden wachsenden Verständnis bezüglich kritischer Operationsschritte – haben zu einer wesentlichen Reduktion schwerwiegender Komplikationen geführt. Um darüber hinaus das Outcome für die Patient*innen zu verbessern, sind neben der Reduktion der Komplikationsrate auch ein besseres Verständnis bezüglich der hüftdysplasieassoziierten Begleitpathologien essenziell.
Latency mitigation using applied HMMs for mixed reality-enhanced intuitive teleoperation in intelligent robotic welding
Authors: Su Yunpeng , Lloyd Leo , Chen Xiaoqi , Chase J. Geoffrey 
Published: March 2023

AbstractLatency mitigation is crucial to increasing operational success, ease of use, and product quality in telemanipulation tasks when remotely guiding complex robotic systems. Hardware limitations have created a gap in performance optimization due to large teleoperation delays, which machine learning techniques could fill with lower time, improved performance, and reduced operating costs. Hidden Markov models (HMMs), in particular, have been explored to alleviate the issue due to their relative ease of use. A mixed reality-enhanced intuitive teleoperation framework for immersive and intuitive telerobotic welding is presented. The proposed system implements an HMM generative algorithm to learn and predict human-welder motion to enable a low-cost solution, combining smoothing and forecasting techniques to minimize robotic teleoperation time delay. The predicted welding motion system is simple to implement, can be used as a general solution to solve time delays, and is accurate. More specifically, it provides a 66% RMSE reduction compared to the application without HMM, which may be further optimized by up to 38%. Experiments show the HMM generative algorithm lets humans conduct tele-robot-assisted welding with better performance.
The Role of Multistakeholder Platforms in Environmental Governance: Analyzing Stakeholder Perceptions in Kalomo District, Zambia, Using Q-Method
Authors: Siangulube Freddie S. 
Published: March 2023

AbstractMultistakeholder platforms (MSPs) are increasingly applied in environmental governance as institutions to collectively negotiate challenges, opportunities, and policy options in contested landscapes. However, their contributions and effectiveness depend on how stakeholders perceive and frame the role of MSPs in addressing social and environmental challenges. Despite this dependence, stakeholder perceptions of MSPs are currently under-researched. Hence this empirical study carried out in Zambia’s Kalomo District asks: how do stakeholder groups perceive the role of MSPs in addressing landscape challenges, given the context of the dual land tenure system, and what does this imply for the implementation of integrated landscape approaches? This study uses Q-methodology to analyze the perceptions of purposefully selected stakeholders from state institutions, civil society organizations, land users, and others familiar with existing MSPs at the district and village levels. The findings reveal three narratives. The first one presents MSPs as institutions that foster dialogue. The second narrative foregrounds the role of the government and private sector, despite acknowledging the diversity of stakeholders in MSPs. In this narrative, MSPs should focus on supporting market-driven solutions to resolve landscape challenges. The third narrative recognizes power imbalances and considers MSPs as institutions to identify policy gaps and needs. The first two narratives are positioned in Dryzek’s discourse classification as environmental problem-solving, while the third inclines toward green radicalism. Despite this divergence, there was consensus that MSPs have the potential to harmonize policies in a dual governance system and encourage dialogue between stakeholders to reconcile landscape challenges.
Anatomical landmarks for localisation of the anterior ethmoidal artery: a combined radiological and cadaveric (endoscopic) study
Authors: Naidu Livashin , Sibiya Lindokuhle A. , Aladeyelu Okikioluwa S. , Rennie Carmen O. 
Published: March 2023

Abstract
Purpose
The anterior ethmoidal artery is a major surgical landmark that is susceptible to iatrogenic injury during surgery of the anterior ethmoidal sinus, frontal sinus, and skull base. The present study aimed to define the location of the anterior ethmoidal artery in relation to specific anatomical landmarks using radiological imaging and endoscopic dissection.

Methods
Eighty-six anterior ethmoidal arteries were assessed using computed tomography scans (bilateral analyses) and forty anterior ethmoidal arteries were assessed using cadaveric specimens (bilateral analyses). The skull base, anterior nasal spine, anterior axilla of the middle turbinate, and nasal axilla were morphometrically analysed to determine their reliability as anterior ethmoidal artery landmarks.

Results
Distances to the skull base, anterior nasal spine, and nasal axilla displayed statistically significant differences between sexes and sides (p < 0.05). All landmarks demonstrated excellent reliability as anatomical landmarks for the localisation of the anterior ethmoidal artery, radiologically and endoscopically (ICC values ranged from 0.94 to 0.99).

Conclusion
The middle turbinate axilla was the most reliable landmark, due to the lack of statistically significant differences according to sex and laterality, and the high inter-rater agreement between measurements. Anatomical knowledge of variations and relationships observed in the present study can be applied to surgeries of the anterior ethmoidal sinus, frontal sinus, and skull base to improve localisation of the anterior ethmoidal artery, preoperatively and intraoperatively, and avoid iatrogenic injury of the vessel.
Associations between endometriosis and adverse pregnancy and perinatal outcomes: a population-based cohort study
Authors: Gebremedhin Amanuel T. , Mitter Vera R. , Duko Bereket , Tessema Gizachew A. , Pereira Gavin F. 
Published: March 2023

Abstract
Purpose
To examine the association between endometriosis and adverse pregnancy and perinatal outcomes (preeclampsia, placenta previa, and preterm birth).

Methods
A population-based retrospective cohort study was conducted among 468,778 eligible women who contributed 912,747 singleton livebirths between 1980 and 2015 in Western Australia (WA). We used probabilistically linked perinatal and hospital separation data from the WA data linkage system’s Midwives Notification System and Hospital Morbidity Data Collection databases. We used a doubly robust estimator by combining the inverse probability weighting with the outcome regression model to estimate adjusted risk ratios (RR) and 95% confidence intervals (CIs).

Results
There were 19,476 singleton livebirths among 8874 women diagnosed with endometriosis. Using a doubly robust estimator, we found pregnancies in women with endometriosis to be associated with an increased risk of preeclampsia with RR of 1.18, 95% CI 1.11–1.26, placenta previa (RR 1.59, 95% CI 1.42–1.79) and preterm birth (RR 1.45, 95% CI 1.37–1.54). The observed association persisted after stratified by the use of Medically Assisted Reproduction, with a slightly elevated risk among pregnancies conceived spontaneously.

Conclusions
In this large population-based cohort, endometriosis is associated with an increased risk of preeclampsia, placenta previa, and preterm birth, independent of the use of Medically Assisted Reproduction. This may help to enhance future obstetric care among this population.
The flexibility of the T–X–T hinges between the coordination tetrahedra in various zeolitic frameworks: an empirical structural study
Authors: Baur Werner H. , Fischer Reinhard X. 
Published: March 2023

AbstractIn recent years, a large number of precisely determined crystal structure determinations of zeolites, that is compounds based on open frameworks of coordination tetrahedra, has accumulated. This gives us the opportunity to evaluate them in terms of the flexibility of their bond angles T–X–T which serve as hinges between the coordination tetrahedra in zeolites containing various SiO4, AlO4, PO4 and similarly sized ions. Out of about 7,000 known crystal structure descriptions of zeolites we have selected 1187 which are based on single crystal diffraction studies and have estimated standard deviations of their T–O bond length of 0.01 Å or less. The mean Si–O–Si angle in zeolitic frameworks with T-sites fully occupied by one type of T atoms is 152.9° and these angles range from 127.0° to 180°, the mean for Al–O–Si is 141.9°, ranging from 124.8° to 179.3°. Straight angles Si–O–Si do occur in some zeolites.
Data-driven virtual sensor for online loads estimation of drivetrain of wind turbines
Authors: Kamel Omar , Kretschmer Matthias , Pfeifer Stefan , Luhmann Birger , Hauptmann Stefan , Bottasso Carlo L. 
Published: March 2023

AbstractData-driven approaches have gained interest recently in the field of wind energy. Data-driven online estimators have been investigated and demonstrated in several applications such as online loads estimation, wake center position estimations, online damage estimation. The present work demonstrates the application of machine learning algorithms to formulate an estimator of the internal loads acting on the bearings of the drivetrain of onshore wind turbines. The loads estimator is implemented as a linear state-space model that is augmented with a non-linear feed-forward neural network. The estimator infers the loads time series as a function of the standard measurements from the SCADA and condition monitoring systems (CMS). A formal analysis of the available data is carried out to define the structure of the virtual sensor regarding the order of the models, number of states, architecture of neural networks. Correlation coefficient of 98% in the time domain and matching of the frequency signature are achieved. Several applications are mentioned and discussed in this work such as online estimation of the forces for monitoring and model predictive control applications.
Investigation on the impact of electrical faults on the loads and exposures of wind turbine gears
Authors: Roth Laurenz , Röder Julian , Brimmers Jens , Bosse Dennis , Brecher Christian , Jacobs Georg 
Published: March 2023

AbstractFor the design of a wind turbine, it is necessary that the design process takes into account the stresses of real operation to a high degree of detail so that targeted dimensioning can be carried out. Depending on its design, the drivetrain of a wind turbine includes a gearbox that connects the rotor to the generator. During operation of a wind turbine, transient load conditions can occur due to loopback from the power grid and faults in the frequency converter. The influence of the resulting stress and possible damage to the gears used in the gearbox is unclear in the design phase. While the stresses on the gears can often be simulated with a high degree of accuracy for constant operating conditions and can thus be integrated into the drivetrain design, this is not the state of the art for dynamic load conditions. The objective of this report is a method for considering dynamic loading events in the design of the cylindrical gear stage used in wind turbine gearboxes using a coupled multi-body simulation and a finite element based tooth contact analysis. Afterwards the method is used to quantify the stress on the tooth flank and tooth root due to special electrical events such as short circuits between the frequency converter and generator or power grid faults for various converter designs. The simulation analyses show that different converter concepts have different effects on the resulting gear load during electrical faults, but are not significantly decisive for the accumulated damage due to elastic material behavior between generator and gear.
Simulation methodology for the identification of critical operating conditions of planetary journal bearings in wind turbines
Authors: Lucassen Mattheüs , Decker Thomas , Guzmán Francisco Gutiérrez , Lehmann Benjamin , Bosse Dennis , Jacobs Georg 
Published: March 2023

AbstractThe usage of journal bearings as planetary bearings in wind turbines instead of roller bearings has become more common in recent years. Their usage is advantageous, due to smaller installation space needed compared to roller bearings allowing for higher power densities of wind turbine drive trains. However, this technology presents a challenge since there is currently no standardized approach for the design of planetary journal bearings regarding wear. Due to varying wind speeds and dynamic operating events a large variation of loads has to be considered in the design process of a planetary journal bearing for wind turbines. Some of these loads are considered potentially critical to the journal bearing in terms of wear. Identifying these critical load areas early in the design phase supports a reliable bearing design and wind turbine operation.This paper introduces a method to identify critical operating conditions for planetary journal bearings using a simulation tool chain, which couples a multi body simulation (MBS) model of a wind turbine with an elasto-hydrodynamic (EHD) model of the planetary journal bearing. Based on the EHD results critical operating conditions are determined for the planetary bearing. Furthermore, methods are implemented to reduce the number of required EHD simulations for analysing the bearing design. The combination of the identification of critical operating conditions, while reducing the computational effort leads to a simulation methodology, which enables a faster bearing design assessment considering the wide variation of wind turbine operating conditions. The applicability of this method is demonstrated by a simplified use case.Firstly, this paper introduces the MBS model and the parameter space that describes possible combinations of bearing loads such as forces, moments and rotational speed. Due to the number of combinations and the EHD computing effort, the identified parameter space is secondly sampled statistically to reduce the simulation effort. A risk map is derived from the EHD results, to easily indicate potentially critical operating conditions for the planetary journal bearing.
Model-based NVH optimization of a tractor drivetrain during different phases of a design adaption
Authors: Müller Julius , Jacobs Georg , Ramm Marco , Wischmann Stefan , Jagla Patrick , Berroth Joerg 
Published: March 2023

AbstractThe modern, ever shorter development process of powertrains incorporates many disciplines of mechanical engineering. Among these, the dynamic and acoustic behavior—which is often referred to as noise, vibration, harshness (NVH)—is becoming increasingly important for the consumer’s purchase decision. However, NVH is often only considered in the last steps of the product development as both experimental analysis methods and high-fidelity modeling approaches are time-consuming. In contrast, in early phases of the development process, fast iteration cycles are crucial. Thus, the engineer needs appropriate NVH models for each phase of the development process in order to evaluate design and concept decisions with respect to their NVH implications.This publication shows a methodological guide on how to apply suitable NVH models forward directed in different stages of the development process and thus efficiently implement optimizations. In the early, highly iterative phases of the development process, analytical determination of the excitation behavior as well as simplified finite element simulations are carried out in order to estimate the vibration behavior of the concept. For the first elaborated geometries, frequency response functions can then be determined and thus the influence of e.g. ribbings to NVH behavior can be evaluated. In the later phases, where advanced simulation models have to be set up, a fully parameterized eMBS model of the drivetrain enables an analysis of its operating behavior, from which further optimization potential of the system can be derived. The proposed method is demonstrated on the example of a tractor transaxle development process.
CFD investigation of starvation behaviors in a grease lubricated EHL rolling contact
Authors: Zhang Shuo , Jacobs Georg , Vafaei Seyedmohammad , von Goeldel Stephan , König Florian 
Published: March 2023

AbstractNowadays, more than 90% of all rolling element bearings are grease lubricated. Grease releases oil to separate the contacting surfaces by forming a stable oil film, thus resulting a long service life of a bearing. The film thickness is usually calculated by assuming fully flooded conditions. However, if the amount of released oil is insufficient, the film thickness will be reduced, which is termed as starvation. Grease lubricated rolling bearings have the risk of starvation even at fairly moderate speeds, which implies a high risk of wear and bearing failure. To reduce this risk, an accurate starvation model to predict film thickness under starvation is needed. In this contribution, a new starvation model based on the CFD method is used. The effects of starvation on film thickness and surface deformation are analyzed. For starved condition, film thickness at contact sides still remains fully flooded but decreases around contact center line because of the spring-back resilience of the material. Meanwhile, with increasing speed, the maximum deformation increases.