bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the orthogonality of generalized eigenspaces for the Ornstein–Uhlenbeck operator
Authors: Casarino Valentina , Ciatti Paolo , Sjögren Peter 
Published: August 2021

AbstractWe study the orthogonality of the generalized eigenspaces of an Ornstein–Uhlenbeck operator $${\mathscr {L}}$$
L
in $$\mathbb {R}^N$$

R

N

, with drift given by a real matrix B whose eigenvalues have negative real parts. If B has only one eigenvalue, we prove that any two distinct generalized eigenspaces of $${\mathscr {L}}$$
L
are orthogonal with respect to the invariant Gaussian measure. Then we show by means of two examples that if B admits distinct eigenvalues, the generalized eigenspaces of $${\mathscr {L}}$$
L
may or may not be orthogonal.
German forecasters’ narratives: How informative are German business cycle forecast reports?
Authors: Müller Karsten 
Published: July 2021

AbstractBased on German business cycle forecast reports covering 10 German institutions for the period 1993–2017, the paper analyses the information content of German forecasters’ narratives for German business cycle forecasts. The paper applies textual analysis to convert qualitative text data into quantitative sentiment indices. First, a sentiment analysis utilizes dictionary methods and text regression methods, using recursive estimation. Next, the paper analyses the different characteristics of sentiments. In a third step, sentiment indices are used to test the efficiency of numerical forecasts. Using 12-month-ahead fixed horizon forecasts, fixed-effects panel regression results suggest some informational content of sentiment indices for growth and inflation forecasts. Finally, a forecasting exercise analyses the predictive power of sentiment indices for GDP growth and inflation. The results suggest weak evidence, at best, for in-sample and out-of-sample predictive power of the sentiment indices.
A partition-enhanced least-squares collocation approach (PE-LSC)
Authors: Zingerle P. , Pail R. , Willberg M. , Scheinert M. 
Published: July 2021

AbstractWe present a partition-enhanced least-squares collocation (PE-LSC) which comprises several modifications to the classical LSC method. It is our goal to circumvent various problems of the practical application of LSC. While these investigations are focused on the modeling of the exterior gravity field the elaborated methods can also be used in other applications. One of the main drawbacks and current limitations of LSC is its high computational cost which grows cubically with the number of observation points. A common way to mitigate this problem is to tile the target area into sub-regions and solve each tile individually. This procedure assumes a certain locality of the LSC kernel functions which is generally not given and, therefore, results in fringe effects. To avoid this, it is proposed to localize the LSC kernels such that locality is preserved, and the estimated variances are not notably increased in comparison with the classical LSC method. Using global covariance models involves the calculation of a large number of Legendre polynomials which is usually a time-consuming task. Hence, to accelerate the creation of the covariance matrices, as an intermediate step we pre-calculate the covariance function on a two-dimensional grid of isotropic coordinates. Based on this grid, and under the assumption that the covariances are sufficiently smooth, the final covariance matrices are then obtained by a simple and fast interpolation algorithm. Applying the generalized multi-variate chain rule, also cross-covariance matrices among arbitrary linear spherical harmonic functionals can be obtained by this technique. Together with some further minor alterations these modifications are implemented in the PE-LSC method. The new PE-LSC is tested using selected data sets in Antarctica where altogether more than 800,000 observations are available for processing. In this case, PE-LSC yields a speed-up of computation time by a factor of about 55 (i.e., the computation needs only hours instead of weeks) in comparison with the classical unpartitioned LSC. Likewise, the memory requirement is reduced by a factor of about 360 (i.e., allocating memory in the order of GB instead of TB).
Bioactivites of Penicillium citrinum isolated from a medicinal plant Swertia chirayita
Authors: Sharma Hemant , Rai Arun Kumar , Chettri Rajen , Nigam Poonam Singh 
Published: August 2021

AbstractEndophytes associated with plants have the property to produce active biomolecules with their possible applications in agro-industrial sectors. This study provides a project work on analyzing various activities of fungal endophytes isolated from Swertia chirayita of Sikkim Himalayan region. Among several fungal endophytes screened, isolate UTCRF6 was found most active with the secretion of enzymes protease, cellulase, amylase and chitinase, as well as other metabolites Indoleacetic acid and siderophores. This endophyte was found active in restricting the growth of phyto-pathogens, including strains of Fusarium solani, Colletotrichum gloeosporioides, Alternaria alternata, Pestalotiopsis theae and Sclerotinia sclerotiorum. Morphological and molecular studies of this endophytic fungus showed similarity with Penicillium citrinum.
Graphic abstract
On the cohomology rings of real flag manifolds: Schubert cycles
Authors: Matszangosz Ákos K. 
Published: July 2021

AbstractWe give an algorithm to compute the integer cohomology groups of any real partial flag manifold, by computing the incidence coefficients of the Schubert cells. For even flag manifolds we determine the integer cohomology groups, by proving that any torsion class has order 2 (generalizing a result of Ehresmann). We conjecture that this holds for any real flag manifold. We obtain results concerning which Schubert varieties represent integer cohomology classes, their structure constants and how to express them in terms of characteristic classes. For even flag manifolds and Grassmannians we also describe Schubert calculus. The Schubert calculus can be used to obtain lower bounds for certain real enumerative geometry problems (Schubert problems).
Aperiodic order and spherical diffraction, II: translation bounded measures on homogeneous spaces
Authors: Björklund Michael , Hartnick Tobias , Pogorzelski Felix 
Published: July 2021

AbstractWe study the auto-correlation measures of invariant random point processes in the hyperbolic plane which arise from various classes of aperiodic Delone sets. More generally, we study auto-correlation measures for large classes of Delone sets in (and even translation bounded measures on) arbitrary locally compact homogeneous metric spaces. We then specialize to the case of weighted model sets, in which we are able to derive more concrete formulas for the auto-correlation. In the case of Riemannian symmetric spaces we also explain how the auto-correlation of a weighted model set in a Riemannian symmetric space can be identified with a (typically non-tempered) positive-definite distribution on $$\mathbb {R}^n$$

R

n

. This paves the way for a diffraction theory for such model sets, which will be discussed in the sequel to the present article.
Individual differences in social play behaviour predict alcohol intake and control over alcohol seeking in rats
Authors: Lesscher Heidi M. B. , Achterberg E. J. Marijke , Siviy Stephen M. , Vanderschuren Louk J. M. J. 
Published: August 2021

Abstract
Rationale
Social play behaviour is a rewarding social activity displayed by young mammals, thought to be important for the development of brain and behaviour. Indeed, disruptions of social play behaviour in rodents have been associated with cognitive deficits and augmented sensitivity to self-administration of substances of abuse, including alcohol, later in life. However, the relation between social development and loss of control over substance use, a key characteristic of substance use disorders including alcohol use disorder (AUD), has not been investigated. Moreover, it remains unknown how inherent differences in playfulness relate to differences in the sensitivity to substance use and AUD.

Objective
The objective of this study is to determine how individual differences in juvenile social play behaviour predict alcohol intake and loss of control over alcohol seeking.

Methods
Juvenile male Lister hooded rats were characterized for their tendency to engage in social play behaviour. Subsequently, alcohol consumption and conditioned suppression of alcohol seeking were assessed in the tertiles of rats that showed the most and least social play.

Results
The rats that engaged most in social play behaviour consumed more alcohol than their less playful counterparts. However, whereas the most playful rats showed intact conditioned suppression of alcohol seeking, the least playful rats showed no such suppression.

Conclusion
Individual levels of playfulness predict the sensitivity to alcohol-directed behaviour. Highly playful rats are more prone to alcohol intake, yet show greater control over alcohol seeking. These findings increase our understanding of the relationship between social development and vulnerability to AUD.
Capture of carbon dioxide and hydrogen by engineered Escherichia coli: hydrogen-dependent CO2 reduction to formate
Authors: Leo Felix , Schwarz Fabian M. , Schuchmann Kai , Müller Volker 
Published: July 2021

Abstract
In times of global climate change and the fear of dwindling resources, we are facing different considerable challenges such as the replacement of fossil fuel–based energy carriers with the coincident maintenance of the increasing energy supply of our growing world population. Therefore, CO2 capturing and H2 storing solutions are urgently needed. In this study, we demonstrate the production of a functional and biotechnological interesting enzyme complex from acetogenic bacteria, the hydrogen-dependent CO2 reductase (HDCR), in the well-known model organism Escherichia coli. We identified the metabolic bottlenecks of the host organisms for the production of the HDCR enzyme complex. Here we show that the recombinant expression of a heterologous enzyme complex transforms E. coli into a whole-cell biocatalyst for hydrogen-driven CO2 reduction to formate without the need of any external co-factors or endogenous enzymes in the reaction process. This shifts the industrial platform organism E. coli more and more into the focus as biocatalyst for CO2-capturing and H2-storage.

Key points
• A functional HDCR enzyme complex was heterologously produced in E. coli.
• The metabolic bottlenecks for HDCR production were identified.
• HDCR enabled E. coli cell to capture and store H2and CO2in the form of formate.
Modelling [18F]LW223 PET data using simplified imaging protocols for quantification of TSPO expression in the rat heart and brain
Authors: MacAskill Mark G. , Wimberley Catriona , Morgan Timaeus E. F. , Alcaide-Corral Carlos J. , Newby David E. , Lucatelli Christophe , Sutherland Andrew , Pimlott Sally L. , Tavares Adriana A. S. 
Published: August 2021

Abstract
Purpose
To provide a comprehensive assessment of the novel 18 kDa translocator protein (TSPO) radiotracer, [18F]LW223, kinetics in the heart and brain when using a simplified imaging approach.

Methods
Naive adult rats and rats with surgically induced permanent coronary artery ligation received a bolus intravenous injection of [18F]LW223 followed by 120 min PET scanning with arterial blood sampling throughout. Kinetic modelling of PET data was applied to estimated rate constants, total volume of distribution (VT) and binding potential transfer corrected (BPTC) using arterial or image-derived input function (IDIF). Quantitative bias of simplified protocols using IDIF versus arterial input function (AIF) and stability of kinetic parameters for PET imaging data of different length (40–120 min) were estimated.

Results
PET outcome measures estimated using IDIF significantly correlated with those derived with invasive AIF, albeit with an inherent systematic bias. Truncation of the dynamic PET scan duration to less than 100 min reduced the stability of the kinetic modelling outputs. Quantification of [18F]LW223 uptake kinetics in the brain and heart required the use of different outcome measures, with BPTC more stable in the heart and VT more stable in the brain.

Conclusion
Modelling of [18F]LW223 PET showed the use of simplified IDIF is acceptable in the rat and the minimum scan duration for quantification of TSPO expression in rats using kinetic modelling with this radiotracer is 100 min. Carefully assessing kinetic outcome measures when conducting a systems level as oppose to single-organ centric analyses is crucial. This should be taken into account when assessing the emerging role of the TSPO heart-brain axis in the field of PET imaging.
Egg covering in cavity nesting birds may prevent nest usurpation by other species
Authors: Slagsvold Tore , Wiebe Karen L. 
Published: July 2021

AbstractSome birds cover their eggs with nest material when they leave to forage. It has been suggested that such egg-covering aids thermoregulation or prevents predation but here we present a new hypothesis, that secondary cavity-nesting species cover their eggs to prevent nest usurpation by other birds. When the bottom of the cavity is dark, as when eggs are covered by nest material, it may be difficult for a prospecting competitor to see whether a defending nest owner or a predator is hiding inside the cavity. Competitors may therefore hesitate to enter dark cavities. We filmed 21 great tit (Parus major) nests during the egg-laying period and found that the female spent bouts of highly variable length outside the nest box (range 0.3–250 min,n = 51), so prospecting small passerines would have difficulty predicting whether an aggressive tit owner was in the box or would soon return. We presented prospecting male pied flycatchers (Ficedula hypoleuca) with a dyad of boxes (n = 93), each containing a great tit nest but only one with visible eggs. Flycatchers hesitated more to enter a nest box with no visible tit eggs than a box with exposed eggs. This was most evident for nest boxes with dark versus light interior paint, supporting the idea that better interior illumination makes prospecting birds more confident about entering an unfamiliar cavity. The usurpation and predation hypotheses are not mutually exclusive because both competitors and small predators may hesitate to enter dark, enclosed spaces if visibility is low.Significance statementSome birds deposit a layer of material on top of the eggs when they leave the nest. Several hypotheses have been proposed for such egg covering, for example that it may insulate the eggs and reduce the risk of nest predation. We propose a new hypothesis, namely that secondary hole-nesting birds cover their eggs when they leave the nest to prevent usurpation of the cavity by other birds. Great tits that we filmed at the nest during the egg-laying period could be absent for long periods. To test the hypothesis, we presented male pied flycatchers, potential nest competitors, with a dyad of nest boxes, each containing a great tit nest but only one with visible tit eggs. In support of the prediction, prospecting flycatchers hesitated to enter dark cavities with dark floors relative to boxes with exposed, reflective eggs.
Primary renal sarcomas: imaging features and discrimination from non-sarcoma renal tumors
Authors: Uhlig Johannes , Uhlig Annemarie , Bachanek Sophie , Onur Mehmet Ruhi , Kinner Sonja , Geisel Dominik , Köhler Michael , Preibsch Heike , Puesken Michael , Schramm Dominik , May Matthias , De Visschere Pieter , Weber Marc-André , Surov Alexey 
Published: July 2021

Abstract
Objectives
To assess imaging features of primary renal sarcomas in order to better discriminate them from non-sarcoma renal tumors.

Methods
Adult patients diagnosed with renal sarcomas from 1995 to 2018 were included from 11 European tertiary referral centers (Germany, Belgium, Turkey). Renal sarcomas were 1:4 compared to patients with non-sarcoma renal tumors. CT/MRI findings were assessed using 21 predefined imaging features. A random forest model was trained to predict “renal sarcoma vs. non-sarcoma renal tumors” based on demographics and imaging features.

Results
n = 34 renal sarcomas were included and compared to n = 136 non-sarcoma renal tumors. Renal sarcomas manifested in younger patients (median 55 vs. 67 years, p < 0.01) and were more complex (high RENAL score complexity 79.4% vs. 25.7%, p < 0.01). Renal sarcomas were larger (median diameter 108 vs. 43 mm, p < 0.01) with irregular shape and ill-defined margins, and more frequently demonstrated invasion of the renal vein or inferior vena cava, tumor necrosis, direct invasion of adjacent organs, and contact to renal artery or vein, compared to non-sarcoma renal tumors (p < 0.05, each). The random forest algorithm yielded a median AUC = 93.8% to predict renal sarcoma histology, with sensitivity, specificity, and positive predictive value of 90.4%, 76.5%, and 93.9%, respectively. Tumor diameter and RENAL score were the most relevant imaging features for renal sarcoma identification.

Conclusion
Renal sarcomas are rare tumors commonly manifesting as large masses in young patients. A random forest model using demographics and imaging features shows good diagnostic accuracy for discrimination of renal sarcomas from non-sarcoma renal tumors, which might aid in clinical decision-making.

Key Points
• Renal sarcomas commonly manifest in younger patients as large, complex renal masses.
• Compared to non-sarcoma renal tumors, renal sarcomas more frequently demonstrated invasion of the renal vein or inferior vena cava, tumor necrosis, direct invasion of adjacent organs, and contact to renal artery or vein.
• Using demographics and standardized imaging features, a random forest showed excellent diagnostic performance for discrimination of sarcoma vs. non-sarcoma renal tumors (AUC = 93.8%, sensitivity = 90.4%, specificity = 76.5%, and PPV = 93.9%).
Estimating the Covariance Matrix of the Maximum Likelihood Estimator Under Linear Cluster-Weighted Models
Authors: Soffritti Gabriele 
Published: July 2021

AbstractIn recent years, the research into cluster-weighted models has been intense. However, estimating the covariance matrix of the maximum likelihood estimator under a cluster-weighted model is still an open issue. Here, an approach is developed in which information-based estimators of such a covariance matrix are obtained from the incomplete data log-likelihood of the multivariate Gaussian linear cluster-weighted model. To this end, analytical expressions for the score vector and Hessian matrix are provided. Three estimators of the asymptotic covariance matrix of the maximum likelihood estimator, based on the score vector and Hessian matrix, are introduced. The performances of these estimators are numerically evaluated using simulated datasets in comparison with a bootstrap-based estimator; their usefulness is illustrated through a study aiming at evaluating the link between tourism flows and attendance at museums and monuments in two Italian regions.
Instability and results after non-operative treatment of large anterior glenoid rim fractures: is there a correlation between fragment size or displacement and recurrence?
Authors: Königshausen Matthias , Pätzholz Simon , Coulibaly Marlon , Nicolas Volkmar , Vandemeulebroecke Marc , Schildhauer Thomas Armin , Seybold Dominik 
Published: August 2021

Abstract
Introduction
There is little data available on non-operative treatment of anterior glenoid rim fractures (GRF). Nothing is known about fracture size and displacement in comparison to clinical outcomes and instability in a mainly middle-aged patient population. The aim of this study was to demonstrate the results of non-operative treatment in anterior glenoid rim fractures with the special focus on potential instability/recurrence.

Methods
The inclusion criteria were non-operatively treated anterior GRF of at least ≥ 5 mm width using the age- and gender-matched Constant/Murley score (a.-/g.-CMS) and the Western Ontario Instability Index (WOSI). Radiographic parameters (fracture morphology, displacement, major tuberosity fractures and Hill–Sachs lesion using initial CT and radiographs) and the proportion of the fractured glenoid were detected (2D-CT-circle-method) and osteoarthritis (A.P. and axial radiographs) was classified according to Samilson/Prieto. Proportion of fractured glenoid and medial displacement were correlated with the recurrence rate and the clinical scores.

Results
N = 36 patients could be followed-up after a mean of 4.4 years [12–140 month, average age: 58 (± 13, 33–86) years]. The a.-/g.-CMS was 93 (± 11, 61–100) points, and the WOSI was 81% (± 22%, 35–100%) on average. The mean intraarticular displacement was 4 mm (± 3 mm; 0–14 mm). The 2D-circle-method showed a mean glenoid fracture involvement of 21% (± 11, 10–52%). Two cases of frozen shoulders and one case with biceps pathology were associated with the trauma. Within the followed-up patient group re-instability has occurred in n = 2 patients (6%) within the first two weeks after trauma. Osteoarthritis was found in n = 11 cases. There was no correlation between the scores and the fracture size/displacement [(a.-/g.-CMS vs. displacement: r = − 0.08; p = 0.6; vs. size: r = − 0.29; p = 0.2); (WOSI vs. displacement: r = − 0.14; p = 0.4; vs. size: r = − 0.37; p = 0.06)], but very large (≥ 21%) fractures with displacement ≥ 4 mm showed slightly worse results without significant difference (a.-/g.-CMS p = 0.2; WOSI p = 0.2). The apprehension test was negative in all patients at final follow-up.

Conclusion
Non-operative treatment of anterior GRF was associated with overall good results within a mainly middle-aged larger patient group. Re-instability is rare and is not associated with fragment size but can occur in the first weeks after trauma. Size and dislocation of the fracture is not a criterion for the prognosis of potential instability.

Level of evidence
Level IV, retrospective case series.
A novel electrosurgical divider: performance in a self-controlled tonsillectomy study
Authors: Besser Gerold , Grasl Stefan , Meyer Elias L. , Schnoell Julia , Bartosik Tina J. , Brkic Faris F. , Heiduschka Gregor 
Published: August 2021

Abstract
Purpose
Tonsillectomies are among the most common surgeries in otorhinolaryngology. A novel electrosurgical temperature-controlled instrument (device) promises rapid tonsillectomies and might reduce postoperative pain, but comparative studies to assess performance are warranted.

Methods
This randomized self-controlled clinical trial was conducted from October 2019 to October 2020 at the Department of Otorhinolaryngology, Head and Neck Surgery of the Medical University of Vienna. Forty-eight patients underwent a tonsillectomy with the device on one side and using cold-steel with localized bipolar cauterization on the other side (control). Main outcomes were the time for tonsil removal (per side) and the time to stop bleeding (per side). Secondary measurements were postoperative pain, assessed once on day 0 and five times on days 1, 3, 5, 7, and 10. Postoperative bleeding episodes and consequences were recorded.

Results
Device tonsillectomies were performed significantly faster than controls; the mean surgical time difference was 209 s (p < 0.001, 95% CI 129; 288). Intraoperative blood loss was significantly lower on the device side (all p < 0.05). Postoperative measurements of pain and bleeding were similar for both sides. Two return-to-theatre secondary bleeding events were recorded for the control side.

Conclusion
The novel electrosurgical temperature-controlled divider reduced the tonsillectomy surgical time and intraoperative blood loss, with no apparent negative effects on postoperative pain or bleeding, compared to a cold-steel tonsillectomy with localized bipolar cauterization. In time-restricted settings, the device could be beneficial, particularly after familiarization with device handling.

Trial registration
ClinicalTrials.gov Identifier: NCT03793816.