bluuebunny/crossref_metadata_2025 huggingface dataset:
On a comparison principle and the uniqueness of spectral flow
Authors: Starostka Maciej , Waterstraat Nils
Published: March 2022

The spectral flow is a well‐known quantity in spectral theory that measures the variation of spectra about 0 along paths of selfadjoint Fredholm operators. The aim of this work is twofold. Firstly, we consider homotopy invariance properties of the spectral flow and establish a simple formula which comprises its classical homotopy invariance and yields a comparison theorem for the spectral flow under compact perturbations. We apply our result to the existence of non‐trivial solutions of boundary value problems of Hamiltonian systems. Secondly, the spectral flow was axiomatically characterised by Lesch, and by Ciriza, Fitzpatrick and Pejsachowicz under the assumption that the endpoints of the paths of selfadjoint Fredholm operators are invertible. We propose a different approach to the uniqueness of spectral flow which lifts this additional assumption. As application of the latter result, we discuss the relation between the spectral flow and the Maslov index in symplectic Hilbert spaces.
Status consumption and charitable donations: The power of empowerment
Authors: Klucarova Sona , He Xin
Published: March 2022

Status consumption, the act of consuming market offerings aimed at conferring status on the consumer, has often been portrayed as the opposite of charitable donation behavior. In a departure from prior works, this study examines the connection between these two seemingly contradictory behaviors. The results of seven studies (including one in the Supporting Information Appendix) demonstrate that status consumption, considered a self‐centered behavior, leads to increased charitable donations, a prosocial outcome. This effect is driven by a process of empowerment (i.e., increase in the sense of power that consumers derive from status consumption). The underlying mechanism of empowerment is examined using both mediation and moderation methods. Alternative explanations based on objective and perceived wealth, affect, guilt, static and objective power, and self‐presentation concerns are ruled out. Further investigation demonstrates that mere ownership of a status good is not sufficient; the consumption of the said product needs to take place for the effect to occur. Moreover, the predicted effect is attenuated for consumers who only desire but do not have status consumption and for those who believe in high power distance. Taken together, this study advances our understanding of status consumption by demonstrating how and when it empowers consumers to donate.
Understanding Consequences and Tradeoffs of Melt Processing as a Pretreatment for Enzymatic Depolymerization of Poly(ethylene terephthalate)
Authors: Chang Allen C. , Patel Akanksha , Perry Sarah , Soong Yahue V. , Ayafor Christian , Wong Hsi‐Wu , Xie Dongming , Sobkowicz Margaret J.
Published: March 2022

Melt extrusion pretreatment of poly(ethylene terephthalate) (PET) prior to enzymatic depolymerization with an unpurified leaf branch compost cutinase enzyme cocktail is explored to ascertain the efficiency gained by different processing methods on the enzymatic depolymerization of PET. Specific surface area (SSA) is investigated as a key factor in reducing depolymerization time. Higher SSA substrates (>5.6 mm2 mg−1) show higher depolymerization rates (≈0.88 g L−1 terephthalic acid [TPA] per day) and no induction phase, while lower SSA substrates (≈4.3, 4.4, and 5.6 mm2 mg−1) show, after an initial induction phase, similar depolymerization rates (≈0.46, 0.45, and 0.44 g L−1 TPA per day) despite increases in SSA of up to 30%. The mechanism of enzymatic depolymerization manifests in the appearance of anisotropic pitting. Longer incubation time used to overcome the induction phase in low SSA substrates allows for nearly full recovery of monomeric products, but manual pregrinding of extruded PET sharply increases SSA, depolymerization rate, and substrate crystallinity which may decrease the maximum recycled yield of the product materials. An estimate of the energy cost of increasing SSA is made and its effects on material properties are discussed. This work highlights key material structure and pretreatment aspects influencing the enzymatic recycling of PET.
A Facile Approach for Anisotropic Hydrogel with Light‐Regulated Stiffness and Its Application to Achieve Mechanical Toughening
Authors: Gao Yang , Wang Peiyao , Zhao Fei , Liu Xiao , Wu Jingping , Hu Jian
Published: March 2022

Many load‐bearing tissues in nature obtain high toughness by fabricating anisotropic structures with spatially regulated composition and modulus at the macroscale. This inspires a toughening strategy for hydrogels based on the controlling of modulus heterogeneity. Herein, a facile approach to realize light‐regulated spatial modulus heterogeneity with large contrast in hydrogels is proposed. Ferric citric acid complex (Fe3+/CA‐complex) is used as a light‐responsive ionic cross‐linker, which can first stiffen an alginate/polyacrylamide (Alg/PAAm) hydrogel by coordinating with the Alg to form another network, then realize light‐triggered softening through photoreduction of ferric ions (Fe3+). Based on this, a stripe‐patterned hydrogel with alternating stiff and soft segments can be fabricated through photopatterning. The modulus contrast between the stiff and soft phases can be adjusted by control of several influence factors and the maximum modulus contrast can reach up to 87 times. As a result, the toughness of the stripe‐patterned hydrogel is enhanced by 3.5 times comparing to that hydrogel without a pattern. This approach shows great potential in the synthesis of smart hydrogels with light‐programmable mechanical performances, and may be widely applicable for the hydrogels with functional groups that can coordinate with metal ions.
Isoliquiritigenin Attenuates Adipose Tissue Inflammation and Metabolic Syndrome by Modifying Gut Bacteria Composition in Mice
Authors: Ishibashi Riko , Furusawa Yukihiro , Honda Hiroe , Watanabe Yasuharu , Fujisaka Shiho , Nishikawa Miyu , Ikushiro Shinichi , Kurihara Shin , Tabuchi Yoshiaki , Tobe Kazuyuki , Takatsu Kiyoshi , Nagai Yoshinori
Published: March 2022

Scope

Isoliquiritigenin (ILG) has been reported to attenuate adipose tissue inflammation and metabolic disorder; however, the underlying mechanisms remain to be elucidated. The aim of this study is to elucidate whether ILG shows the anti‐inflammatory and antimetabolic syndrome effects through gut microbiota modification.

Methods and results

Mice are fed a high‐fat diet (HFD) with or without ILG for up to 12 weeks. The effect of ILG on body weight, blood glucose level, adipose tissue inflammation, gut barrier function, and gut microbiota composition are investigated. ILG supplementation alleviates HFD‐induced obesity, glucose tolerance, and insulin resistance and suppresses inflammatory gene expression in epididymal white adipose tissue (eWAT). Moreover, ILG supplementation modifies gut bacterial composition by increasing the abundance of antimetabolic disease‐associated species (e.g., Parabacteroides goldsteinii and Akkemansia muciniphila) and up‐regulated genes associated with gut barrier function. Fecal microbiome transplantation (FMT) from ILG‐fed donors counteract HFD‐induced body and eWAT weight changes, inflammation‐related gene expression, glucose tolerance, and insulin resistance, thereby suggesting that ILG‐responsive gut bacteria exerts anti‐inflammatory and antimetabolic syndrome effects.

Conclusion

Alterations in gut bacteria underly the beneficial effects of ILG against adipose tissue inflammation and metabolic disorders. ILG may be a promising prebiotic for the prevention and treatment of metabolic syndrome.
Applications of chemical exchange saturation transfer magnetic resonance imaging in identifying genetic markers in gliomas
Authors: Jiang Shanshan , Wen Zhibo , Ahn Sung Soo , Cai Kejia , Paech Daniel , Eberhart Charles G. , Zhou Jinyuan
Published: March 2022

Chemical exchange saturation transfer (CEST) imaging is an important molecular magnetic resonance imaging technique that can image numerous low‐concentration biomolecules with water‐exchangeable protons (such as cellular proteins) and tissue pH. CEST, or more specially amide proton transfer‐weighted imaging, has been widely used for the detection, diagnosis, and response assessment of brain tumors, and its feasibility in identifying molecular markers in gliomas has also been explored in recent years. In this paper, after briefing on the basic principles and quantification methods of CEST imaging, we review its early applications in identifying isocitrate dehydrogenase mutation status, MGMT methylation status, 1p/19q deletion status, and H3K27M mutation status in gliomas. Finally, we discuss the limitations or weaknesses in these studies.
On the metric determination of linear dependence graph
Authors: Salman Muhammad , Rasheed Nimra , Ur Rehman Masood , Cao Jinde
Published: March 2022

The metric on a connected graph G is a mapping which assigns to each pair of vertices in G the length of a shortest path between u and v. In this article, we consider the linear dependence graph associated with a finite dimensional vector space and determine its metric properties, namely, the center, the periphery, metric‐degree sequence, metric‐degree polynomial, metric dimension, connected metric dimension, local metric dimension, strong metric dimension, and the metric polynomial.
Bamboo natural fiber and PAN fiber used as a reinforced brake friction material: Developed asbestos‐free brake pads
Authors: Kumar Naresh , Mehta Vikas , Kumar Sushil , Grewal J. S. , Ali Sarafat
Published: March 2022

Recently, natural fibers have shown their importance in certain kinds of composites. The trending composites are mostly made using organic fiber due to their good eco‐friendly nature, their easy availability, and reasonable cost. Natural fibers are replacing synthetic fibers in every field. In this research article, natural fibers like bamboo fiber and PAN fiber have been utilized to develop a new kind of hybrid composite and compared to aramid fiber reinforcement. The brake pads were fabricated with the inclusion of various percentages of mass of bamboo fibers and PAN fiber (3%–12%) with an equal ratio of Aramid fiber (3%–6%) in the hydraulic hind brake molding device. The chemical, mechanical, physical, tribological, and thermal properties were evaluated.
Polybenzimidazole membrane for efficient copper removal from aqueous solutions
Authors: Coppola Roxana E. , Lozano Hernán E. , Contin Mario , Canneva Antonela , Molinari Fabricio N. , Abuin Graciela C. , D'Accorso Norma B.
Published: March 2022

Thin films of poly(2,5‐benzimidazole) (ABPBI) polymer were prepared by the casting method, and sorption studies with aqueous CuSO4 solutions were performed. Surface interaction between Cu(II) and the membrane was studied using spectroscopic analysis (Fourier transform infrared, Raman and X‐ray photoelectron), showing a strong interaction through nitrogen groups of ABPBI and Cu(II). The best conditions for Cu(II) uptake were at pH = 5 and a soaking time of 60 min. In these conditions, the sorption isotherm was best fitted by the Langmuir equation and the maximum sorption capacity was estimated to be 1.5 mmol g−1. Due to sorption pH dependency, elution studies using hydrochloric acid solution were carried out, showing an almost complete removal of bonded Cu(II) when immersing the ABPBI membrane in the acidic solution. Surface morphology of membranes was studied using scanning electron microscopy–energy‐dispersive X‐ray spectroscopy, showing no major changes with sorption and elution experiments. These results show that ABPBI can be considered as an alternative polymer for the development of new materials for the removal of heavy metals. © 2022 Society of Industrial Chemistry.
Tailoring 3D shapes of polyhedral milliparticles by adjusting orthogonal projection in a microfluidic channel
Authors: Zhou Chenchen , Jia He , Liang Shuaishuai , Li Yongjian , Li Jiang , Chen Haosheng
Published: March 2022

Polyhedral milliparticles (PMPs) have promising applications in self‐assembly, tissue engineering, mechanical engineering, and photonics. The shapes and sizes of the PMPs have great impact on their functions. To date, the reported methods for adjusting the shapes and sizes of PMPs are still limited. Especially, it remains a challenge to fabricate the PMPs with high asymmetry. Here, we present a facile and efficient approach that focuses on the alteration of the relative positions between the microchannel and the UV light to tailor the shaping process of the PMPs. By tuning the rotation angle and translation displacement, a variety of monodisperse PMPs with both centrosymmetric and noncentrosymmetrical structures are synthesized, including tetrahedra, pentahedra, hexahedra, and so forth. Moreover, the polymeric PMPs are loaded with silica nanoparticles and further sintered into silica. The obtained silica PMPs hold great potential for the applications such as machining tools, abrasives, and electronics.
Adsorbate‐Induced Modifications in the Optical Response of the Si(553)–Au Surface
Authors: Chandola Sandhya , Sanna Simone , Hogan Conor , Speiser Eugen , Plaickner Julian , Esser Norbert
Published: March 2022

The conductivity of substrate‐supported metallic nanowires can be adjusted, e.g., by strain or adsorbates. In this article, the effect of atomic hydrogen and toluene‐3,4‐dithiol (TDT) adsorption on the quasi‐1D structures of the Si(553)‐(5 × 2)–Au reconstruction is investigated. Reflectance anisotropy spectroscopy (RAS) and infrared ellipsometry reveal optical signatures of the surface. Spectral modifications related to the adsorbate exposure suggest the activation of adsorption‐induced interband transitions. Density functional theory (DFT) calculations reproduce the spectral modifications and explain their origin. Preferential adsorption on sites located at the step edges of the structure occurs independent of the type of adsorbate and induces a charge transfer between electronic states related to the step edges and the Au dimer rows. This charge redistribution modifies the electronic structure close to the Fermi level, enhances the dimerization of the Au chains, and strongly influences the low‐energy region of the RAS spectra. While previous studies employed atomic H as a chief adsorbate, it is shown here that even molecular H deeply modifies the Si(553)–Au optical response. Structural modification of Au–Si(553) by H and TDT adsorbates as suggested from recent ab initio calculations are verified.
An improved exponential EWMA chart for monitoring time between events
Authors: Zhang Yang , Shang Yanfen , Hu Xuelong , Li An‐Da
Published: March 2022

Many control charts have been developed for monitoring the time between adverse events (TBE) to improve the quality of processes. In practice, the decrease in the TBE mean usually implies a deterioration of the process, while the increase indicates an improvement of the process. In this paper, an improved lower‐sided EWMA control chart is developed based on the power of the TBE observations to detect the decreasing TBE mean. Furthermore, an optimization model is developed to design the proposed EWMA chart, including the determination of the power and smoothing parameters to ensure the best overall performance. Simulation studies show the proposed EWMA chart is best among several charts for monitoring small shifts, and performs better than most alternative methods in detecting moderate shifts. Moreover, the in‐control performance of the proposed method with parameter estimation is studied via many numerical simulations. Finally, a real data example is given to further illustrate the application and sensitiveness of the improved EWMA chart.
Quantum Verification and Estimation with Few Copies
Authors: Morris Joshua , Saggio Valeria , Gočanin Aleksandra , Dakić Borivoje
Published: March 2022

As quantum technologies advance, the ability to generate increasingly large quantum states has experienced rapid development. In this context, the verification and estimation of large entangled systems represent one of the main challenges in the employment of such systems for reliable quantum information processing. Though the most complete technique is undoubtedly full tomography, the inherent exponential increase of experimental and post‐processing resources with system size makes this approach infeasible even at moderate scales. For this reason, there is currently an urgent need to develop novel methods that surpass these limitations. This review article presents novel techniques focusing on a fixed number of resources (sampling complexity), and thus prove suitable for systems of arbitrary dimension. Specifically, a probabilistic framework requiring at best only a single copy for entanglement detection is reviewed, together with the concept of selective quantum state tomography, which enables the estimation of arbitrary elements of an unknown state with a number of copies that is low and independent of the system's size. These hyper‐efficient techniques define a dimensional demarcation for partial tomography and open a path for novel applications.
Photoelectric Detection of Nitrogen‐Vacancy Centers Magnetic Resonances in Diamond: Role of Charge Exchanges with Other Optoelectrically Active Defects
Authors: Bourgeois Emilie , Soucek Josef , Hruby Jaroslav , Gulka Michal , Nesladek Milos
Published: March 2022

The photoelectric detection of nitrogen‐vacancy (NV) magnetic resonance (PDMR) in diamond, used for spin state detection and based on reading the photocurrent resulting from NV ionization, offers physical and technical advantages for the development of miniaturized and scalable quantum sensors, as well as solid‐state quantum information devices integrated with electronics. Charge exchanges between NV centers and other optoelectrically active defects in diamond are an essential part of the PDMR scheme, impacting the spin‐state control and the performances of the photoelectric readout. Through experimental characterization and modeling, processes governing the spin‐state contrast, in particular the hole carrier contribution to the photocurrent and the role of acceptor‐type defects are discussed. Such acceptor defects can act as traps for free electrons resulting from NV photoionization. Consequently, the hole current can increase at resonance, ultimately leading to an inversion of the sign of PDMR resonances, i.e. to a positive spin contrast. Based on these findings, a method to improve PDMR performances in terms of spin contrast and photoelectric detection rate by selectively ionizing low‐energy acceptor defects using a bias red illumination is proposed. This method is shown to lead to a significant improvement of the photoelectric spin detection sensitivity, important for future practical devices.
Bayesian semi‐parametric modeling of covariance matrices for multivariate longitudinal data
Authors: Papageorgiou Georgios
Published: March 2022

The article develops marginal models for multivariate longitudinal responses. Overall, the model consists of five regression submodels, one for the mean and four for the covariance matrix, with the latter resulting by considering various matrix decompositions. The decompositions that we employ are intuitive, easy to understand, and they do not rely on any assumptions such as the presence of an ordering among the multivariate responses. The regression submodels are semi‐parametric, with unknown functions represented by basis function expansions. We use spike‐slap priors for the regression coefficients to achieve variable selection and function regularization, and to obtain parameter estimates that account for model uncertainty. An efficient Markov chain Monte Carlo algorithm for posterior sampling is developed. The simulation study presented investigates the gains that one may have when considering multivariate longitudinal analyses instead of univariate ones, and whether these gains can counteract the negative effects of missing data. We apply the methods on a highly unbalanced longitudinal dataset with four responses observed over a period of 20 years.
Revisiting the effect of supermajority requirements on fiscal outcomes
Authors: Hankins William B.
Published: March 2022

I use matching methods on a panel of U.S. states over the period 1960–2008 to test whether the adoption of a supermajority requirement impacts state‐level expenditures and tax revenue. While two‐way fixed effects (TWFE) models show that general expenditures, welfare expenditures, and total tax revenue per capita are lower following adoption of a supermajority requirement, I also find evidence of heterogeneous treatment effects, and worse, violation of the common trends assumption. Matching estimates fail to support the conclusions of the TWFE models, suggesting that supermajority requirements do not have a robust effect on government expenditures or tax revenue.
Endoplasmic reticulum stress regulates pyroptosis in BPDE‐induced BEAS‐2B cells
Authors: Zhang Qiao , He Xi , Yu Qi , Liu Yitong , Zhu Yonghang , Yang Liu , Shang Pingping , Zhang Jiatong , Liu Hong , Feng Feifei
Published: March 2022

Benzo(a)pyrene(B(a)P), as the main representative of polycyclic aromatic hydrocarbons, can promote inflammation and many chronic pulmonary diseases. However, the underlying mechanism of Benzo(a)pyrene‐7,8‐diol‐9,10‐epoxide (BPDE)‐induced human bronchial epithelial cell pyroptosis related to endoplasmic reticulum stress (ERS) has not been elucidated. This study focused on the effects of BPDE on ERS and pyroptosis in human bronchial epithelial cells (BEAS‐2B), and explored the relationship between ERS and pyroptosis. BEAS‐2B cells were stimulated with 0.50, 0.75, and 1.00 μmol/L BPDE for 24 h to detect ERS and pyroptosis. After inhibition of ERS with 4‐phenylbutyrate (4‐PBA), pyroptosis of BEAS‐2B cells was tested. The results showed that BPDE decreased the cell viability, changed the morphological structure of endoplasmic reticulum and increased the expression levels of GRP78 and p‐PERK. After BPDE treatment, the cell membrane was damaged and incomplete under transmission electron microscope; Hoechst 33342/PI fluorescence staining showed that the number of PI‐positive cells was enhanced. The expression levels of GSDMD‐N, cleaved‐caspase 1, and cleaved‐IL‐1β were elevated, and the expression levels of IL‐1β, IL‐18, and NLRP3 protein were improved. In BPDE combined with 4‐PBA intervention group, the rate of PI‐positive cells was reduced, the expression levels of GRP78, GSDMD‐N, and cleaved‐caspase 1 were decreased, and the expression levels of IL‐1β, IL‐18, and NLRP3 were decreased. In conclusion, BPDE could induce ERS and pyroptosis in BEAS‐2B cells, and ERS may promote the occurrence of BPDE‐induced pyroptosis.
Facial paralysis with ear droop in calves associated with exposure to steelworks slag, possibly due to vanadium toxicity
Authors: Jewell Natalie , Jones Jeff , Floyd Toby , Davies Gunhild , Payne Jo
Published: March 2022

A group of 5 to 7‐week‐old calves presented with unusual clinical signs that included facial paralysis and ear droop. Postmortem examination of a single calf ruled out infectious causes and confirmed that the calf had ingested a gritty slag, a by‐product from the steel industry. The slag was being used on a farm on grazing land but had been stored in such a way that the calves had been exposed. Analysis of the ingested material and tissue analysis confirmed the presence of vanadium at concentrations likely to be significant. A literature search confirmed two other similar cases in Sweden and New Zealand where steel slag exposure had been associated with similar clinical signs; in the former case, these had been attributed to acute vanadium toxicity.
Partitioning Sites for Invention in Serlio’s and Palladio’s Palazzi
Authors: Mols Nick M. L.
Published: March 2022

Throughout history, diagrammatic drawing formed a modus operandi for generating architectural typologies, creating spatial hierarchies, codifying ratio and proportion while defining the shape grammar of the edifice. Despite the prominence of the diagram in architectural design, no account of designing irregular sites during the Renaissance exists, nor how diagrams partition space. This paper’s computer-aided graphical analysis elucidates how to design irregular sites by reading principles of partitioning in the treatises of Serlio and Palladio. Through the numeric lexicons of Serlio, Palladio and Bertotti Scamozzi, this paper uncovers the ways the transformative power of the diagram codifies irregular typologies while ordering its spatial hierarchies. The cases of Serlio’s and Palladio’s geometrical reckoning illuminate a commonplace working method for partitioning Renaissance palazzi where the heuristic diagram visually uncovers the architect’s idea by combining context, site, and function that result in architectural inventions.
Langzeitüberleben bei Krebs: Definitionen, Konzepte und Gestaltungsprinzipien von Survivorship-Programmen
Authors: Bergelt Corinna , Bokemeyer Carsten , Hilgendorf Inken , Langer Thorsten , Rick Oliver , Seifart Ulf , Koch-Gromus Uwe
Published: March 2022

Aufgrund von diagnostischen und therapeutischen Fortschritten in der Hämatologie und Onkologie und entsprechend steigenden Überlebensaussichten ist ein stetiger Zuwachs der Gruppe von Langzeitüberlebenden mit und nach Krebs (Cancer Survivor) in Deutschland zu verzeichnen. Obwohl das bereits vorhandene deutsche Gesundheitswesen vielfältige Versorgungsangebote vorhält, die auch für Langzeitüberlebende verfügbar sind, ist die Versorgungssituation dieser Gruppe nicht zufriedenstellend. So bedarf es zum einen der Entwicklung von Orientierungshilfen für Langzeitüberlebende, zum anderen sollten neue und innovative Versorgungsprogramme für Überlebende (Survivorship-Programme) entwickelt werden. Der Beitrag gibt einen Überblick über die Problematik, definiert relevante Begrifflichkeiten und formuliert Kernaspekte für die Ausgestaltung von Survivorship-Programmen für Langzeitüberlebende nach Krebserkrankung.
A simple agent-based model to simulate 3D tumor-induced angiogenesis considering the evolution of the hypoxic conditions of the cells
Authors: Benítez José María , García-Mozos Luis , Santos Anastasio , Montáns Francisco Javier , Saucedo-Mora Luis
Published: March 2022

In tumors, angiogenesis (conformation of a new vasculature from another primal one) is produced with the releasing of tumor angiogenic factors from hypoxic cells. These angiogenic substances are distributed around the tumor micro-environment by diffusion. When they reach the primal blood vessel bed, the sprouting and branching of a new micro-vascular network is produced. These new capillaries will supply oxygen to cells so that their hypoxic state is overcome. In this work, a new and simple 3D agent-based model to simulate tumor-induced angiogenesis is presented. In this approach, the evolution of the hypoxic conditions in cells along the related conformation of the new micro-vessels is considered. The importance that the relative position of the primal vasculature and tumor structure takes in the final distribution of the new micro-vasculature has also been addressed. The diffusion of angiogenic factors and oxygen has been modelled at the targets by numerical convolution superposition of the analytical solution from the sources. Qualitative and quantitative results show the importance of tip endothelial cells in overcoming hypoxic conditions in cells at early stages of angiogenesis. At final stages, anastomosis plays an important role in the reduction of hypoxia in cells.
Importance of substrate quality and clay content on microbial extracellular polymeric substances production and aggregate stability in soils
Authors: Olagoke Folasade K. , Bettermann Antje , Nguyen Phuong Thi Bich , Redmile-Gordon Marc , Babin Doreen , Smalla Kornelia , Nesme Joseph , Sørensen Søren J. , Kalbitz Karsten , Vogel Cordula
Published: March 2022

We investigated the effects of substrate (cellulose or starch) and different clay contents on the production of microbial extracellular polymeric substances (EPS) and concomitant development of stable soil aggregates. Soils were incubated with different amounts of montmorillonite (+ 0.1%, + 1%, + 10%) both with and without two substrates of contrasting quality (starch and cellulose). Microbial respiration (CO2), biomass carbon (C), EPS-protein, and EPS-polysaccharide were determined over the experimental period. The diversity and compositional shifts of microbial communities (bacteria/archaea) were analysed by sequencing 16S rRNA gene fragments amplified from soil DNA. Soil aggregate size distribution was determined and geometric mean diameter calculated for aggregate formation. Aggregate stabilities were compared among 1–2-mm size fraction. Starch amendment supported a faster increase than cellulose in both respiration and microbial biomass. Microbial community structure and composition differed depending on the C substrate added. However, clay addition had a more pronounced effect on alpha diversity compared to the addition of starch or cellulose. Substrate addition resulted in an increased EPS concentration only if combined with clay addition. At high clay addition, starch resulted in higher EPS concentrations than cellulose. Where additional substrate was not provided, EPS-protein was only weakly correlated with aggregate formation and stability. The relationship became stronger with addition of substrate. Labile organic C thus clearly plays a role in aggregate formation, but increasing clay content was found to enhance aggregate stability and additionally resulted in the development of distinct microbial communities and increased EPS production.
Acupuncture and its effect on cytokine and chemokine profiles in seasonal allergic rhinitis: a preliminary three-armed, randomized, controlled trial
Authors: Gellrich Donata , Pfab Florian , Ortiz Miriam , Binting Sylvia , Brinkhaus Benno , Gröger Moritz
Published: March 2022

Purpose

Numerous studies have demonstrated effectiveness for acupuncture in the treatment of seasonal allergic rhinitis (SAR). However, the underlying mechanism remains still unclear.

Methods

29 SAR patients were recruited from a large randomized, controlled trial investigating the efficacy of acupuncture in SAR. 16 patients were treated by acupuncture plus rescue medication (RM, cetirizine), 6 patients received sham acupuncture plus RM and 8 patients RM alone over 8 weeks. Patients were blinded to the allocation to real or sham acupuncture. At baseline and different time-points during intervention, plasma and nasal concentration of mediators of various biological functions were determined in addition to validated disease-specific questionnaires.

Results

The concentration of biomarkers related to the Th1-, Th2-, and Treg-cluster was not changed in patients who received acupuncture, in neither plasma nor nasal fluid. However, with respect to eotaxin and some unspecific pro-inflammatory cytokines (IL-1b, IL-8, IP-10, MIP-1b, MCP-1), acupuncture led to a, partially significantly, lower nasal concentration than sham acupuncture or RM. Furthermore, the nasal symptom score was significantly reduced in patients only after real acupuncture.

Conclusion

In SAR, acupuncture reduces the intranasal unspecific inflammation, but does not seem to act immunologically on the Th1–Th2-imbalance.
Neurobiologische und neurochemische Mechanismen der Placeboanalgesie
Authors: Asan Livia , Bingel Ulrike , Kunkel Angelika
Published: March 2022

Hintergrund

Die Wirksamkeit von Schmerztherapien kann durch behandlungsbezogene Erwartungen wesentlich moduliert werden. Dies wird besonders unter Betrachtung des starken Placeboeffekts bei Schmerzen deutlich (die sog. Placeboanalgesie).

Fragestellung

Was ist bisher über die neurobiologischen Grundlagen der Placeboanalgesie und die beteiligten neurochemischen Transmittersysteme bekannt?

Material und Methoden

Fokussierte Auswahl wesentlicher Schlüsselpublikationen und strukturierte Darlegung mechanistischer Konzepte und aktueller Theorien basierend auf neuester Evidenz.

Ergebnisse

In experimentellen Studien konnte die Wirkung der Placeboanalgesie insbesondere durch bildgebende Verfahren über eine Aktivitätsänderung in Hirnarealen der Schmerzverarbeitung und der kognitiven Kontrolle beschrieben werden. Beteiligte Neurotransmitter sind körpereigene Opioide und das Dopaminsystem.

Schlussfolgerungen

Die Placeboanalgesie ist mit komplexen neurobiologischen und -physiologischen Mechanismen verbunden. Das Verständnis dieser Prozesse sollte gezielt genutzt werden, um therapeutische Ansätze in der Schmerzmedizin zu optimieren.
Internal igneous growth, doming and rapid erosion of a mature ocean island: the Miocene evolution of Maio (Cabo Verde)
Authors: Samrock Lisa K. , Hansteen Thor H. , Dullo Wolf-Christian , Wartho Jo-Anne
Published: March 2022

Maio Island (Cabo Verde Archipelago) is composed of uplifted Early Mesozoic MORB-type pillow lavas and deep-sea sediments, unconformably overlain and intruded by Miocene igneous rocks. Combined structural analyses and 40Ar–39Ar dating were used to constrain the Miocene evolution of Maio. Structures and ages of uplifted Mesozoic sequences and crosscutting Miocene dykes showed that numerous intrusive events were associated with the intense growth of an igneous core complex in the middle to upper crust, causing semi-circular doming and partial disruption of the Mesozoic strata. Two nosean nephelinite dykes cut the Valanginian Batalha Formation and yielded phlogopite 40Ar–39Ar ages of 10.405 ± 0.033 Ma and 10.570 ± 0.053 Ma (2σ errors). A nosean nephelinite dyke that cuts the overlying Valanginian to Early Aptian Morro Formation yielded an age of 9.273 ± 0.020 Ma. Combined with existing K–Ar and 40Ar–39Ar ages, this confirmed a main period of island growth between ~ 16 and 8.7 Ma. We re-interpreted extensive polymict conglomerates, which occur below the Late Miocene Monte Penoso Formation, as landslide deposits. A nephelinite lava clast yielded a phlogopite 40Ar–39Ar age of 8.666 ± 0.0274 Ma, which represents a maximum age for these landslides and thus confined a period of large-scale flank collapses and erosion to between 8.7 and 6.7 Ma. Flank collapses and further mass wasting during this period may have rejuvenated the igneous activity, i.e., resulting in the formation of the Tortonian/Messinian Monte Penoso and Malhada Pedra Formations, due to decompression-induced melting at upper mantle depths. Such interaction between flank collapses and rejuvenated volcanism may be a key to better understand ocean island evolution worldwide.
High-resolution downscaling of CMEMS oceanographic reanalysis in the area of the Tuscany Archipelago (Italy)
Authors: Bendoni Michele , Fattorini Maria , Taddei Stefano , Brandini Carlo
Published: March 2022

A native nested configuration of the ROMS model is implemented on the marine area between the Ligurian and Tyrrhenian basins, which includes the Tuscany Archipelago. Initial and boundary conditions are provided by the CMEMS Mediterranean Sea Physical Reanalysis product (1/16°), feeding the parent ROMS model (BLUE, 1/72°), in which a high-resolution grid is nested (PURPLE, 1/216°). Atmospheric forcing comes from a downscaled version of ERA5 reanalysis. Temperature and salinity profiles from gliders and floats, and HF-radar-derived surface currents, are compared to model outputs within the high-resolution area for the whole year 2017. Results show the downscaling procedure is able to reduce model errors for temperature profiles, whereas errors in salinity profiles remain comparable. However, the downscaled model cannot recover large errors inherited from the parent one. The mean bias largest values found in both temperature and salinity profiles may be explained by a model underestimation of the depth of stable stratification limit with respect to field data. Errors in surface currents are reduced for the downscaled dynamics and appear to be uncorrelated to the original CMEMS product, being surface dynamics less affected by initial condition than by atmospheric forcing. A simple scalar metric, to quantify the error in the surface current vector fields from observations and models, is proposed. The novel metric allows to better quantify the improvement gained by the downscaling procedure.
Revisiting the building of past snapshots — a replication and reproduction study
Authors: Maes-Bermejo Michel , Gallego Micael , Gortázar Francisco , Robles Gregorio , Gonzalez-Barahona Jesus M.
Published: March 2022

Context

Building past source code snapshots of a software product is necessary both for research (analyzing the past state of a program) and industry (increasing trustability by reproducibility of past versions, finding bugs by bisecting, backporting bug fixes, among others). A study by Tufano et al. showed in 2016 that many past snapshots cannot be built.

Objective

We replicate Tufano et al.’s study in 2020, to verify its results and to study what has changed during this time in terms of compilability of a project. Also, we extend it by studying a different set of projects, using additional techniques for building past snapshots, with the aim of extending the validity of its results.

Method

(i) Replication of the original study, obtaining past snapshots from 79 repositories (with a total of 139,389 commits); and (ii) Reproduction of the original study on a different set of 80 large Java projects, extending the heuristics for building snapshots (300,873 commits).

Results

We observed degradation of compilability over time, due to vanishing of dependencies and other external artifacts. We validated that the most influential error causing failures in builds are missing external artifacts, and the less influential is compiling errors. We observed some facts that could lead to the effect of the build tool on past compilability.

Conclusions

We provide details on what aspects have a strong and a shallow influence on past compilability, giving ideas of how to improve it. We could extend previous research on the matter, but could not validate some of the previous results. We offer recommendations on how to make this kind of studies more replicable.
Toward Passive Acoustic Monitoring of Lemurs: Using an Affordable Open-Source System to Monitor Phaner Vocal Activity and Density
Authors: Markolf Matthias , Zinowsky Max , Keller Judith Katharina , Borys Johannes , Cillov Ali , Schülke Oliver
Published: March 2022

Developing new cost-effective methods for monitoring the distribution and abundance of species is essential for conservation biology. Passive acoustic monitoring (PAM) has long been used in marine mammals and has recently been postulated to be a promising method to improve monitoring of terrestrial wildlife as well. Because Madagascar’s lemurs are among the globally most threatened taxa, this study was designed to assess the applicability of an affordable and open-source PAM device to estimate the density of pale fork-marked lemurs (Phaner pallescens). Using 12 playback experiments and one fixed transect of four automated acoustic recorders during one night of the dry season in Kirindy Forest, we experimentally estimated the detection space for Phaner and other lemur vocalizations. Furthermore, we manually annotated more than 10,000 vocalizations of Phaner from a single location and used bout rates from previous studies to estimate density within the detection space. To truncate detections beyond 150 m, we applied a sound pressure level (SPL) threshold filtering out vocalizations below SPL 50 (dB re 20 μPa). During the dry season, vocalizations of Phaner can be detected with confidence beyond 150 m by a human listener. Within our fixed truncated detection area corresponding to an area of 0.07 km2 (detection radius of 150 m), we estimated 10.5 bouts per hour corresponding to a density of Phaner of 38.6 individuals/km2. Our density estimates are in line with previous estimates based on individually marked animals conducted in the same area. Our findings suggest that PAM also could be combined with distance sampling methods to estimate densities. We conclude that PAM is a promising method to improve the monitoring and conservation of Phaner and many other vocally active primates.
Institutional change and entrepreneurship as occupational choice—The case of South Korea
Authors: Schüler Diana
Published: March 2022

Even though research on the influence of institutions on entrepreneurial activities has recently gained scholarly attention, most studies are quantitative cross-country analyses that assume response homogeneity. Qualitative single-country studies that provide deeper insights into institutional peculiarities are still rare, especially in the East Asian context. Based on qualitative data generated from semi-structured interviews, this study examines the institutional environment for entrepreneurship in South Korea and its latest changes to explain the recent wave of newly established corporations. Building on Scott’s distinction of institutional dimensions, this article demonstrates how significant changes in regulative institutions pushed forward by the Korean central government have decreased individual financial risks and have created a surge in business foundations. At the same time, normative institutions have remained almost unchanged, while changes of the cognitive institutional dimension in the form of entrepreneurship education are underway. The findings suggest that regulative institutions play a bigger role for entrepreneurial activities than cognitive or normative institutions, as people start a business despite unfavorable informal institutions. Theory should therefore reevaluate the importance and effective power of each institutional dimension on entrepreneurial activities. Policymakers who put high emphasis on regulative institutions should pay attention to potential moral hazards arising from generous support programs.
Metal Artifacts in Attenuation and Phase Contrast X-Ray Microcomputed Tomography: A Comparative Study
Authors: Glinz J. , Zabler S. , Kastner J. , Senck S.
Published: March 2022

Background

Metal artifacts arising around high-density components are a widely known problem in X-ray computed tomography (XCT) for both medical and industrial applications. Although phase contrast imaging XCT (PCI-XCT) is known to be less prone to metal artifacts caused by beam hardening, so far only little effort was made for its comparison to other, more established methods.

Objective

In the course of this work, this absence in literature is addressed by a quantitative comparison of PCI-XCT to attenuation contrast XCT (AC-XCT).

Methods

A polymer specimen including four Ti6Al4V inserts was investigated by PCI- and AC-XCT with different pre-filter settings and metal artifact reduction (MAR) algorithm. Artifacts and image quality were evaluated by a streak index which provides a quantitative metric for the assessment of streak artifacts and contrast-to-noise ratio (CNR).

Results

Results showed that streak artifacts are significantly reduced in PCI-XCT and only matched by AC-XCT in combination with hardware pre-filtering of the X-ray beam and post-processing by a MAR algorithm. However, hardware pre-filtering leads to worse CNR and artifacts close to the surface of metal inserts could not be removed sufficiently by the MAR algorithm.

Conclusions

This work demonstrates the potential of PCI-XCT for the reduction of metal artifacts and presents the first quantitative comparison to established AC-XCT methods.
Learning a Discriminative Feature Attention Network for pancreas CT segmentation
Authors: Huang Mei-xiang , Wang Yuan-jin , Huang Chong-fei , Yuan Jing , Kong De-xing
Published: March 2022

Accurate pancreas segmentation is critical for the diagnosis and management of diseases of the pancreas. It is challenging to precisely delineate pancreas due to the highly variations in volume, shape and location. In recent years, coarse-to-fine methods have been widely used to alleviate class imbalance issue and improve pancreas segmentation accuracy. However, cascaded methods could be computationally intensive and the refined results are significantly dependent on the performance of its coarse segmentation results. To balance the segmentation accuracy and computational efficiency, we propose a Discriminative Feature Attention Network for pancreas segmentation, to effectively highlight pancreas features and improve segmentation accuracy without explicit pancreas location. The final segmentation is obtained by applying a simple yet effective post-processing step. Two experiments on both public NIH pancreas CT dataset and abdominal BTCV multi-organ dataset are individually conducted to show the effectiveness of our method for 2D pancreas segmentation. We obtained average Dice Similarity Coefficient (DSC) of 82.82±6.09%, average Jaccard Index (JI) of 71.13± 8.30% and average Symmetric Average Surface Distance (ASD) of 1.69 ± 0.83 mm on the NIH dataset. Compared to the existing deep learning-based pancreas segmentation methods, our experimental results achieve the best average DSC and JI value.
The influence of CEO compensation on employee engagement
Authors: Hendriks Martijn , Burger Martijn , Commandeur Harry
Published: March 2022

The soaring compensation levels of chief executive officers (CEOs) have spurred an intense debate about its outcomes. This paper examines an understudied outcome in this regard: employee engagement. Using a dynamic panel model with data from 336 publicly listed firms across 26 countries, we find that employee engagement is generally unaffected by CEO (over)compensation. However, negative effects emerge under specific conditions. First, employee engagement declines with negative media coverage about CEO compensation. Second, employee engagement declines with greater CEO (over)compensation in the financial sector, which is a sector with extraordinary levels of CEO compensation and compensation controversies. The findings suggest that a ceiling effect exists, at which point negative effects emerge and employee engagement becomes relevant in determining CEO compensation policies, while the general insensitivity of employee engagement to CEO compensation can help explain the soaring CEO compensation levels.