bluuebunny/crossref_metadata_2025 huggingface dataset:
Visualizing stem cells in vivo using magnetic resonance imaging
Authors: Moonshi Shehzahdi Shebbrin , Wu Yuao , Ta Hang Thu
Published: October 2021

Stem cell (SC) therapies displayed encouraging efficacy and clinical outcome in various disorders. Despite this huge hype, clinical translation of SC therapy has been disheartening due to contradictory results from clinical trials. The ability to monitor migration and engraftment of cells in vivo represents an ideal strategy in cell therapy. Therefore, suitable imaging approach to track MSCs would allow understanding of migratory and homing efficiency, optimal route of delivery and engraftment of cells at targeted location. Hence, longitudinal tracking of SCs is crucial for the optimization of treatment parameters, leading to improved clinical outcome and translation. Magnetic resonance imaging (MRI) represents a suitable imaging modality to observe cells non‐invasively and repeatedly. Tracking is achieved when cells are incubated prior to implantation with appropriate contrast agents (CA) or tracers which can then be detected in an MRI scan. This review explores and emphasizes the importance of monitoring the distribution and fate of SCs post‐implantation using current contrast agents, such as positive CAs including paramagnetic metals (gadolinium), negative contrast agents such as superparamagnetic iron oxides and 19F containing tracers, specifically for the in vivo tracking of MSCs using MRI.

This article is categorized under:

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology

Therapeutic Approaches and Drug Discovery > Emerging Technologies
Radiative classical gravitational observables at $$ \mathcal{O} $$(G3) from scattering amplitudes
Authors: Herrmann Enrico , Parra-Martinez Julio , Ruf Michael S. , Zeng Mao
Published: October 2021

Abstract

We compute classical gravitational observables for the scattering of two spinless black holes in general relativity and $$ \mathcal{N} $$
N
=8 supergravity in the formalism of Kosower, Maybee, and O’Connell (KMOC). We focus on the gravitational impulse with radiation reaction and the radiated momentum in black hole scattering at $$ \mathcal{O} $$
O
(G3) to all orders in the velocity. These classical observables require the construction and evaluation of certain loop-level quantities which are greatly simplified by harnessing recent advances from scattering amplitudes and collider physics. In particular, we make use of generalized unitarity to construct the relevant loop integrands, employ reverse unitarity, the method of regions, integration-by-parts (IBP), and (canonical) differential equations to simplify and evaluate all loop and phase-space integrals to obtain the classical gravitational observables of interest to two-loop order. The KMOC formalism naturally incorporates radiation effects which enables us to explore these classical quantities beyond the conservative two-body dynamics. From the impulse and the radiated momentum, we extract the scattering angle and the radiated energy. Finally, we discuss universality of the impulse in the high-energy limit and the relation to the eikonal phase.
Uniform convergence of operator semigroups without time regularity
Authors: Dobrick Alexander , Glück Jochen
Published: October 2021

When we are interested in the long-term behaviour of solutions to linear evolution equations, a large variety of techniques from the theory of $$C_0$$

C
0

-semigroups is at our disposal. However, if we consider for instance parabolic equations with unbounded coefficients on $${\mathbb {R}}^d$$

R

d

, the solution semigroup will not be strongly continuous, in general. For such semigroups many tools that can be used to investigate the asymptotic behaviour of $$C_0$$

C
0

-semigroups are not available anymore and, hence, much less is known about their long-time behaviour. Motivated by this observation, we prove new characterisations of the operator norm convergence of general semigroup representations—without any time regularity assumptions—by adapting the concept of the “semigroup at infinity”, recently introduced by M. Haase and the second named author. Besides its independence of time regularity, our approach also allows us to treat the discrete-time case (i.e. powers of a single operator) and even more abstract semigroup representations within the same unified setting. As an application of our results, we prove a convergence theorem for solutions to systems of parabolic equations with the aforementioned properties.
High-resolution association mapping with libraries of immortalized lines from ancestral landraces
Authors: Würschum Tobias , Weiß Thea M. , Renner Juliane , Friedrich Utz H. , Gierl Alfons , Jonczyk Rafal , Römisch-Margl Lilla , Schipprack Wolfgang , Schön Chris-Carolin , Schrag Tobias A. , Leiser Willmar L. , Melchinger Albrecht E.
Published: October 2021

Key message

Association mapping with immortalized lines of landraces offers several advantages including a high mapping resolution, as demonstrated here in maize by identifying the causal variants underlying QTL for oil content and the metabolite allantoin.

Landraces are traditional varieties of crops that present a valuable yet largely untapped reservoir of genetic variation to meet future challenges of agriculture. Here, we performed association mapping in a panel comprising 358 immortalized maize lines from six European Flint landraces. Linkage disequilibrium decayed much faster in the landraces than in the elite lines included for comparison, permitting a high mapping resolution. We demonstrate this by fine-mapping a quantitative trait locus (QTL) for oil content down to the phenylalanine insertion F469 inDGAT1-2as the causal variant. For the metabolite allantoin, related to abiotic stress response, we identified promoter polymorphisms and differential expression of an allantoinase as putative cause of variation. Our results demonstrate the power of this approach to dissect QTL potentially down to the causal variants, toward the utilization of natural or engineered alleles in breeding. Moreover, we provide guidelines for studies using ancestral landraces for crop genetic research and breeding.
Physiologically based kinetic modelling predicts the in vivo relative potency of riddelliine N-oxide compared to riddelliine in rat to be dose dependent
Authors: Widjaja Frances , Wesseling Sebastiaan , Rietjens Ivonne M. C. M.
Published: October 2021

Pyrrolizidine alkaloids (PAs) are toxic plant constituents occurring often in their N-oxide form. This raises the question on the relative potency (REP) values of PA-N-oxides compared to the corresponding parent PAs. The present study aims to quantify the in vivo REP value of riddelliine N-oxide compared to riddelliine using physiologically based kinetic (PBK) modelling, taking into account that the toxicity of riddelliine N-oxide depends on its conversion to riddelliine by intestinal microbiota and in the liver. The models predicted a lower Cmax and higher Tmax for the blood concentration of riddelliine upon oral administration of riddelliine N-oxide compared to the Cmax and Tmax predicted for an equimolar oral dose of riddelliine. Comparison of the area under the riddelliine concentration–time curve (AUCRID) obtained upon dosing either the N-oxide or riddelliine itself revealed a ratio of 0.67, which reflects the in vivo REP for riddelliine N-oxide compared to riddelliine, and appeared to closely match the REP value derived from available in vivo data. The models also predicted that the REP value will decrease with increasing dose level, because of saturation of riddelliine N-oxide reduction by the intestinal microbiota and of riddelliine clearance by the liver. It is concluded that PBK modeling provides a way to define in vivo REP values of PA-N-oxides as compared to their parent PAs, without a need for animal experiments.
Psychocardiological assessment in the acute phase of the takotsubo syndrome
Authors: Weihs Valerie , Pogran Edita , Kunschitz Evelyn , Weihs Wolfgang , Prinz Erika , Eichenberg Christiane , Fiegl Jutta , Friedrich Oliver , Huber Kurt
Published: October 2021

Objective

To analyze the psychocardiological profile and the clinical characteristics in the acute phase of takotsubo syndrome (TTS).

Methods

Prospective multicenter cohort study of TTS patients evaluating the clinical characteristics as well as the prevalence of somatic, depressive, panic, stress and anxiety disorders. Assessment of illness perception and resilience in the acute phase of the syndrome.

Results

All 27 evaluated TTS patients were female with a mean age of 68 years (±11.4 years). The apical type of TTS was found in 60% of patients, followed by the combined type of TTS in 30% of patients. Main clinical symptom leading to hospital admission was chest pain in nearly 80% of patients. An ST-segment elevation mimicking acute myocardial infarction was found in 44% of patients and T wave inversion in 26% of patients. An endogenous (emotional) stress event was found in 17 patients (63.0%), an exogenous (physical) stress event in 5 patients (18.5%) and a combined stress event in 2 patients (7.4%). In 11.1% of patients (n = 3) no stress event could be found. Moderate to high levels of illness threatening were found in 48% of patients and low to moderate resilience scores were found in 40% of patients. Somatic disorders were found in half of the patients (56%) followed by depressive disorders in 26% of patients.

Conclusion

Moderate to low resilience scores and moderate to high levels of illness threatening can be seen in the acute phase of TTS, reflecting the severity of the experience as an adverse life event. Patients suffering from TTS present in the acute phase with a high prevalence of somatic disorders and relatively high prevalence of depressive disorders.
Verkürzte Lebensdauertests von Zahnradgetrieben unter Lastkollektivbeanspruchung
Authors: Hein Michael , Tobie Thomas , Stahl Karsten
Published: October 2021

Im Rahmen dieses Beitrags wird ein Vorgehensmodell zur Planung und Durchführung von verkürzten Lebensdauertests bei Zahnradgetrieben vorgestellt, um einen zuverlässigen Betrieb zu ermöglichen. Die Methodik wurde im Hinblick auf die üblicherweise auftretende Lastkollektivbelastung hergeleitet, ist aber ebenso auf Einstufenbelastungen, wie sie häufig in Prüfläufen verwendet werden, anwendbar.

Das allgemeine Vorgehen ist in zwei Schritte gegliedert. Zunächst erfolgt eine Raffung des zu Grunde liegenden Lastkollektiv unter Beibehaltung des maßgeblichen Schadensmechanismus. Anschließend werden die Versuche unter den Gesichtspunkten statistische Auswertung, detaillierte Lebensdauerberechnung und Werkstoffanalyse geplant und ausgewertet. Im Rahmen dieses Beitrags wird besonders die statistische Auswertung betrachtet, welche auch eine Abschätzung der Zuverlässigkeit von Zahnradgetrieben bei Lastkollektivbelastung ermöglicht.
Experimentelle Untersuchungen an feststoffgeschmierten Wälzlagern im Hochvakuum
Authors: Werner M. , Emrich S. , Sauer B. , Kopnarski M. , Thielen S.
Published: October 2021

Im Rahmen dieses Beitrags werden Ergebnisse einer Untersuchung an feststoffgeschmierten Wälzlagern vorgestellt. Betrachtet werden dabei Lager, welche einen speziellen, modifizierten Käfig verwenden. Die Käfigtaschen des Käfigs dienen dabei, zusätzlich zu ihrer ursprünglichen Funktion, der Führung der Wälzkörper, als Schmierstoffdepot. Es werden zunächst Prüfaufbau und die Versuchsbedingungen erläutert und in diesem Zusammenhang wird gezeigt, dass der in diesem Beitrag verwendete Aufbau, verglichen mit dem Aufbau vorangegangener Arbeiten, eine deutlich reduzierte Streuung aufweist. Als eine nicht zu vernachlässigende Fehlerquelle bei der gravimetrischen Bestimmung des Käfigtaschenverschleißes wurde das hygroskopische Verhalten des Polymercompounds identifiziert. Einer Verfälschung dieser Messergebnisse durch die unkontrollierte Feuchtigkeitsaufnahme aus der Umgebung, muss durch einen zeitlich vorgelagerten Trocknungsprozess unter definierten Bedingungen vorgebeugt werden. Zudem wird gezeigt, dass die Käfigtaschen sowohl durch den Innenring des Lagers, als auch durch die Wälzkörper verschlissen werden. Hierbei wird eine Messmethode zur Ermittlung der, durch den Innenring verschlissenen, Materialmenge vorgestellt. Durch Oberflächenanalysen der Messingstruktur des Käfigs wird eine Reduzierung des Zinks nachgewiesen, sowie eine Änderung der Oberflächenstruktur festgestellt. Als Ursache wird ein Sublimieren des Zinks aufgrund der Versuchsbedingungen vermutet. Weiterhin wird gezeigt, dass die Prüftemperatur von 300 °C zu einem Schrumpfen der Lagerringe führt. Eine Vorwegnahme dieser Maßverringerung ist durch Temperierung bei 300 °C für 48 h möglich.
Whole blood viscosity is associated with baseline cerebral perfusion in acute ischemic stroke
Authors: Gyawali Prajwal , Lillicrap Thomas Patrick , Tomari Shinya , Bivard Andrew , Holliday Elizabeth , Parsons Mark , Levi Christopher , Garcia-Esperon Carlos , Spratt Neil
Published: October 2021

Whole blood viscosity (WBV) is the intrinsic resistance to flow developed due to the frictional force between adjacent layers of flowing blood. Elevated WBV is an independent risk factor for stroke. Poor microcirculation due to elevated WBV can prevent adequate perfusion of the brain and might act as an important secondary factor for hypoperfusion in acute ischaemic stroke. In the present study, we examined the association of WBV with basal cerebral perfusion assessed by CT perfusion in acute ischaemic stroke. Confirmed acute ischemic stroke patients (n = 82) presenting in hours were recruited from the single centre. Patients underwent baseline multimodal CT (non-contrast CT, CT angiography and CT perfusion). Where clinically warranted, patients also underwent follow-up DWI. WBV was measured in duplicate within 2 h after sampling from 5-mL EDTA blood sample. WBV was significantly correlated with CT perfusion parameters such as perfusion lesion volume, ischemic core volume and mismatch ratio; DWI volume and baseline NIHSS. In a multivariate linear regression model, WBV significantly predicted acute perfusion lesion volume, core volume and mismatch ratio after adjusting for the effect of occlusion site and collateral status. Association of WBV with hypoperfusion (increased perfusion lesion volume, ischaemic core volume and mismatch ratio) suggest the role of erythrocyte rheology in cerebral haemodynamic of acute ischemic stroke. The present findings open new possibilities for therapeutic strategies targeting erythrocyte rheology to improve cerebral microcirculation in stroke.
The impact of intermediaries on a negotiation: an approach from game theory
Authors: López Susana , Owen Guillermo , Saboya Martha
Published: October 2021

Standard approaches to model interaction networks are limited in their capacity to describe the nuances of real communication. We present a game theoretical framework to quantify the effect of intermediaries on the interaction between agents. Inspired by the seminal work Myerson (1977). on cooperative structures in cooperative games, we set the basis for multidimensional network analysis within game theory. More specifically, an extension of the point-arc game Feltkamp and van den Nouwe51 land (1992). is introduced, generalizing the analysis of cooperative games to multigraphs. An efficient algorithm is proposed for the computation of Shapley value of this game. We prove the validity of our approach by applying it to a intermediaries network model. We are able to recover meaningful results on the dependence of the game outcome on the intermediaries network. This work contributes to the optimal design of networks in economic environments and allows the ranking of players in complex networks.
Advances in ultrasonography: image formation and quality assessment
Authors: Hasegawa Hideyuki
Published: October 2021

Delay-and-sum (DAS) beamforming is widely used for generation of B-mode images from echo signals obtained with an array probe composed of transducer elements. However, the resolution and contrast achieved with DAS beamforming are determined by the physical specifications of the array, e.g., size and pitch of elements. To overcome this limitation, adaptive imaging methods have recently been explored extensively thanks to the dissemination of digital and programmable ultrasound systems. On the other hand, it is also important to evaluate the performance of such adaptive imaging methods quantitatively to validate whether the modification of the image characteristics resulting from the developed method is appropriate. Since many adaptive imaging methods have been developed and they often alter image characteristics, attempts have also been made to update the methods for quantitative assessment of image quality. This article provides a review of recent developments in adaptive imaging and image quality assessment.
Short-Term Exposure to Nature and Benefits for Students’ Cognitive Performance: a Review
Authors: Mason Lucia , Ronconi Angelica , Scrimin Sara , Pazzaglia Francesca
Published: October 2021

There is growing interest recently in the outdoor environment surrounding schools where students spent time during breaks, in-school activities, and after-school programs. Several reviews have examined the impact of long-term exposures to nearby nature on students’ academic achievement, but none has focused on the effects of short-term contacts with nature on students’ cognitive performance. The aim of this review is to understand the context in which short-term passive exposures to greenness occur, how cognitive performance is measured, and the conditions under which cognitive benefits emerge at various educational levels. We reviewed 14 studies in the extant literature that report investigations involving students at different educational levels, from elementary school to university, in a short exposure to nature lasting from 10 to 90 min during a study day. The review shows that in 12 out of the 14 studies, across educational levels, cognitive benefits emerge in terms of directed attention restoration from mental fatigue due to contact with nature. A no-cost opportunity to sustain students’ cognition is a break in a green environment after mentally demanding activities.
Does Educational Mismatch Affect Emigration Behaviour?
Authors: Wanner Philippe , Pecoraro Marco , Tani Massimiliano
Published: October 2021

This paper uses linked Swiss administrative and survey data to examine the relationship between educational mismatch in the labour market and emigration decisions, carrying out the analysis for both Swiss native and previous immigrant workers. In turn, migrants’ decisions separate returning home from onward migration to a third country. We find that undereducation is positively associated with the probability of emigration and return to the country of origin. In contrast, the reverse relationship is found between overeducation and emigration, especially among non-European immigrant workers. According to the predictions of the traditional model of migration, based on self-selection, migrants returning home are positively selected relative to migrants emigrating to other countries. We also find that immigrants from a country outside the EU27/EFTA have little incentive to return home and generally accept jobs for which they are mismatched in Switzerland. These results highlight the relevance to understand emigration behaviours in relation to the type of migrant that is most integrated, and productive, in the Swiss market, hence enabling better migration and domestic labour market policy design.
Evolving continuous optimisers from scratch
Authors: Lones Michael A.
Published: October 2021

This work uses genetic programming to explore the space of continuous optimisers, with the goal of discovering novel ways of doing optimisation. In order to keep the search space broad, the optimisers are evolved from scratch using Push, a Turing-complete, general-purpose, language. The resulting optimisers are found to be diverse, and explore their optimisation landscapes using a variety of interesting, and sometimes unusual, strategies. Significantly, when applied to problems that were not seen during training, many of the evolved optimisers generalise well, and often outperform existing optimisers. This supports the idea that novel and effective forms of optimisation can be discovered in an automated manner. This paper also shows that pools of evolved optimisers can be hybridised to further increase their generality, leading to optimisers that perform robustly over a broad variety of problem types and sizes.
A deterministic Wigner approach for superposed states
Authors: Cervenka Johann , Kosik Robert , Nedjalkov Mihail
Published: October 2021

The Wigner formalism is a convenient way of describing quantum mechanical effects through a framework of distribution functions in phase space. Currently, there are stochastic and deterministic approaches in use. In our deterministic method, the critical discretization of the diffusion term is done through the utilization of an integral formulation of the Wigner equation. This deterministic method is studied in the context of superposed quantum states as a precursor to simulations of entangled states.
Adjustment of Electromagnetic Properties in SrRuO3 via Ru Content
Authors: Zhang Zhe , Yang Xingming , Wang Yan , Zhang Tiantian , Sun Yuan , Duan F. M. , Zhang A. M. , Wu Xiaoshan
Published: October 2021

Magnetism of materials may be adjusted by varying the adjacent magnetic ions in materials, such as Ru4+ in SrRuO3. We here report a study of the structure, electro-transport and magnetic properties of poly-crystallized SrRuxO3, which is synthesized by solid-state reaction. Results show that all the synthesized SrRuxO3 samples remain the single phase, and the grain size increases with increasing the Ru content. A semiconducting behavior with x ≤ 1 and a Fermi Liquid behavior with x > 1 are observed and determined. At 10 K, the saturated magnetic moment increases with x from 21.02 to 29.82 (emu/g), while the coercivity decreases from 5100 to 910 (Oe), which are also confirmed by the first principle calculations.
Nanopore Genome Sequencing and Variant Analysis of the Susceptible Candida auris Strain L1537/2020, Salvador, Brazil
Authors: de Jong Auke W. , Francisco Elaine C. , de Almeida João Nóbrega , Brandão Igor B. , Pereira Felicidade M. , Dias Pedro H. Presta , de Miranda Costa Magda M. , de Souza Jordão Regiane T. , Vu Duong , Colombo Arnaldo L. , Hagen Ferry
Published: October 2021

Candida auris has been reported worldwide, but only in December 2020, the first strain from a COVID-19 patient in Brazil was isolated. Here, we describe the genome sequence of this susceptible C. auris strain and performed variant analysis of the genetic relatedness with strains from other geographic localities.
‘Believe in me, and I will too’: a study of how teachers’ expectations instilled confidence in Grade 10 students
Authors: Johnston Olivia , Wildy Helen , Shand Jennifer
Published: October 2021

Teacher expectation research has continued to establish an association between what teachers expect of their students and what students accomplish academically. These expectations affect students when they are communicated by teachers through differential treatment in the class, but no qualitative research has sought adolescent students’ points of view about how they experience teacher expectation effects. This paper presents new research findings that explainhowGrade 10 students experienced their teachers’ expectations in ways that they reflected impacted their academic outcomes. Classic grounded theory methods were used to develop this new knowledge, which has implications for how teachers are educated for, and practice, interacting with secondary school students. The findings are grounded in data from more than 100 interviews with students and 175 classroom observations in three Western Australian metropolitan public secondary schools. Students’ voices are projected, explaining how their teachers convey high academic expectations through classroom interactions that instil confidence in students. The discussion invokes a connection to Bandura’s Social Cognitive Theory and its enduring tenants of self-efficacy beliefs and mastery learning experiences.
A rational route to transformative decisions
Authors: Villiger Daniel
Published: October 2021

According to Paul (Transformative experience, 1st edn, Oxford University Press, 2014), transformative experiences pose a challenge to decision theory since their value cannot be anticipated. Building on Pettigrew’s (in: Lambert, Schwenkler (eds) Becoming someone new: essays on transformative experience, choice, and change, Oxford University Press, pp 100–121, 2020) redescription, this paper presents a new approach to how and when transformative decisions can nevertheless be made rationally. Thanks to fundamental higher-order facts that apply to any kind of experience, an agent always at least knows the general shape of the utility space. This in combination with the knowledge about the non-transformative alternative in the choice set can enable rational decision-making despite the presence of a transformative experience. For example, this paper’s approach provides novel arguments for why gender transition (cf. McKinnon in Res Philosophica 92(2):419–440, 2015) or staying childfree (cf. Barnes in Philos Phenomenol Res 91(3):775–786, 2015) can be rational.
NFC: a deep and hybrid item-based model for item cold-start recommendation
Authors: Bernardis Cesare , Cremonesi Paolo
Published: October 2021

New items, also called cold-start items, are introduced every day in the catalogs of numerous online systems. Due to the absence of previous preferences, recommending these items is difficult but important task for a recommender system. For this reason, the item cold-start recommendation problem still represents an interesting research topic for the community. In this work, we propose Neural Feature Combiner (NFC), a novel deep learning, item-based approach for cold-start item recommendation. The model learns to map the content features of the items into a low-dimensional hybrid embedding space. The features that compose the embeddings are then combined in order to reproduce collaborative item similarity values. We compare NFC with three variants of the same model that learn from user feedback, showing the advantages of learning from similarities in terms of accuracy and convergence time. With an extensive set of experiments on four datasets, we show that NFC outperforms several cutting edge approaches in the top-n recommendation task of cold-start items. Results in extremely cold (i.e., with a very low amount of interactions for training) and cold-warm hybrid scenarios prove that NFC effectively exploits collaborative information, leading to state-of-the-art accuracy. We finally conduct a qualitative analysis of the embeddings generated by different models, and we provide an analysis of the importance that different models assign to the input features, empirically demonstrating the robustness of the hybrid representations produced by our new model.
19F MRI Imaging Strategies to Reduce Isoflurane Artifacts in In Vivo Images
Authors: Staal Alexander H. J. , Veltien Andor , Srinivas Mangala , Scheenen Tom W. J.
Published: October 2021

Purpose

Isoflurane (ISO) is the most commonly used preclinical inhalation anesthetic. This is a problem in 19F MRI of fluorine contrast agents, as ISO signals cause artifacts that interfere with unambiguous image interpretation and quantification; the two most attractive properties of heteronuclear MRI. We aimed to avoid these artifacts using MRI strategies that can be applied by any pre-clinical researcher.

Procedures

Three strategies to avoid ISO chemical shift displacement artifacts (CSDA) in 19F MRI are described and demonstrated with measurements of 19F-containing agents in phantoms and in vivo (n = 3 for all strategies). The success of these strategies is compared to a standard Rapid Acquisition with Relaxation Enhancement (RARE) sequence, with phantom and in vivo validation. ISO artifacts can successfully be avoided by (1) shifting them outside the region of interest using a narrow signal acquisition bandwidth, (2) suppression of ISO by planning a frequency-selective suppression pulse before signal acquisition or by (3) preventing ISO excitation with a 3D sequence with a narrow excitation bandwidth.

Results

All three strategies result in complete ISO signal avoidance (p < 0.0001 for all methods). Using a narrow acquisition bandwidth can result in loss of signal to noise ratio and distortion of the image, and a frequency-selective suppression pulse can be incomplete when B1-inhomogeneities are present. Preventing ISO excitation with a narrow excitation pulse in a 3D sequence yields the most robust results (relative SNR 151 ± 28% compared to 2D multislice methods, p = 0.006).

Conclusion

We optimized three easily implementable methods to avoid ISO signal artifacts and validated their performance in phantoms and in vivo. We make recommendation on the parameters that pre-clinical studies should report in their method section to make the used approach insightful.
Geochemical baseline establishment, contamination level and ecological risk assessment of metals and As in the Limoncocha lagoon sediments, Ecuadorian Amazon region
Authors: Carrillo Katty Coral , Rodríguez-Romero Araceli , Tovar-Sánchez Antonio , Ruiz-Gutiérrez Gema , Fuente Javier R. Viguri
Published: October 2021

Purpose

The Limoncocha lagoon, inside a Ramsar site in the Ecuadorian Amazon, increasingly hosts ecotourism and energy development activities. This work estimates the local sediments’ baseline of As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, V and Zn using four methods. This makes it possible to apply single and integrated pollution indices to estimate the contamination level and the ecological risk of the sediments.

Methods

Seven sites were analysed for metal(oid)s by ICP-MS. The local baseline was estimated using the relative cumulative frequency method, the iterative 2σ- and 4σ-outlier-techniques and the normalisation method to a “conservative” element. Combinations of single Cf and Ef and integrated indices (NPI, mNPI, mCd, MEQ, RI, mPELq, mERMq and TRI) were applied.

Results

The relative cumulative frequency method had the best performance for the geochemical baselines. Cf and Ef indices classify sediments from a “low contamination” remote site to the “moderate contamination” and “minor enrichment” of the remaining sites due to As, Cd and Zn concentrations. The overall analysis of the integrated indices results in Ni, Zn and Cu being identified as priority pollutants because they have occasionally been associated with adverse biological effects in the centre of the lagoon and in the most anthropised areas. These are classified as moderately polluted with a medium–low priority risk level.

Conclusions

This work provides sediment baseline and contamination indicators for pollutants, which could be incorporated into the sediment quality assessment and monitoring programme of the Limoncocha lagoon. Ni, Cd and Cr due to the high baseline values in comparison with SQGs, and Cu and Zn due to their potential risk, should be of special attention.

Graphical abstract
The Impact of Residents' Leisure Time Allocation Mode on Individual Subjective Well-being: The Case of China
Authors: Wang Pengfei , Wei Xiang , Yingwei Xu , Xiaodan Cao
Published: October 2021

As the main tension in Chinese society has become that between people's growing need for a better life and unbalanced and inadequate development, leisure activities have become a main factor affecting the subjective well-being of Chinese residents. This study uses micro data from the 2019–2020 Chinese Residents’ Economic Life Survey as the sample, applies the latent class analysis (LCA) method to conduct a joint analysis of all leisure activities of individuals, and then divides individual leisure time modes into four types: general leisure, stationary leisure, family-friendly leisure and sports/health care-related leisure. To overcome endogeneity problems from missing variables, sample selection bias, and two-way causality, this paper uses the Heckman two-step and propensity score matching methods to empirically analyse the impacts of residents' leisure time allocation patterns on individual subjective well-being. The study finds that sports/health care-type leisure is most helpful in improving individual subjective well-being, followed by general leisure, family-friendly leisure and stationary leisure, which have relatively weaker impacts on subjective well-being. The estimation results remain robust and reliable after we introduce the idea of ​​misclassification probability to test the robustness of the findings. On this basis, a group heterogeneity analysis by region, income level, education level, marital status and age is carried out. The research conclusions of this article can help guide residents in rationally allocating their leisure time and provide a policy reference for the construction of leisure facilities in China’s cities.
The influence of community structure on opinion expression: an agent-based model
Authors: Cabrera Benjamin , Ross Björn , Röchert Daniel , Brünker Felix , Stieglitz Stefan
Published: October 2021

Social media has become important in shaping the public discourse on controversial topics. Many businesses therefore monitor different social media channels and try to react adequately to a potentially harmful opinion climate. Still, little is known about how opinions form in an increasingly connected world. The spiral of silence theory provides a way of explaining deviations between the perceived opinion climate and true beliefs of the public. However, the emergence of a spiral of silence on social media is hard to observe because only the thoughts of those who express their opinions are evident there. Recent research has therefore focused on modelling the processes behind the spiral of silence. A particular characteristic of social media networks is the presence of communities. Members of a community tend to be connected more with other members of the same community than with outsiders. Naturally, this might affect the development of public opinion. In the present article we investigate how the number of communities in a network and connectivity between them affects the perceived opinion climate. We find that higher connectivity between communities makes it more likely for a global spiral of silence to appear. Moreover, a network fragmented into more, smaller communities seems to provide more “safe spaces” for a minority opinion to prevail.
Genistein-induced Anticancer Effects on Acute Leukemia Cells Involve the Regulation of Wnt Signaling Pathway Through H4K20me1 Rather Than DNA Demethylation
Authors: Zhou Hua-rong , Shen Jian-zhen , Fu Hai-ying , Zhang Feng
Published: October 2021

Objective

To investigate the effects and mechanisms of genistein on the gene expression in the Wnt pathway in acute leukemia (AL) cells.

Methods

The expression of Wnt pathway genes and cell cycle-related genes were analyzed in two AL cell lines. Pyrophosphate sequencing was performed to determine the methylation degree. Then, the enrichment of H4K20me1 and H3K9ac was determined using ChIP-qPCR. Flow cytometry was used to analyze the cell cycle.

Results

The IC50 of genistein in the two AL cell lines was lower than that for the bone marrow mesenchymal stem cell line. Genistein upregulated H4K20me1, KMT5A and Wnt suppressor genes, including Wnt5a, and downregulated the downstream target genes of Wnt, such as c-myc and β-catenin. The methylation degree and H3K9ac enrichment in the Wnt5a promoter region remained unchanged. However, the enrichment of H4K20me1 in the Wnt5a promoter and coding regions increased. In addition, genistein upregulated Phospho-cdc2, Myt1, Cyclin A, Cyclin E2, p21 and Phospho-histone H3, but downregulated Phospho-wee1. Cell cycle arrest was induced in the G2/M phase.

Conclusion

Genistein inhibits the activation of the Wnt pathway by promoting the expression of Wnt5a through the activation of KMT5A and enrichment of H4K20me1 in the Wnt5a gene promoter and coding regions, rather than demethylation. Genistein also blocks the cell cycle in the G2/M phase. Therefore, genistein is a potential anti-leukemia drug.
In Situ Bulk Observations and Ab Initio Calculations Revealing the Temperature Dependence of Stacking Fault Energy in Fe–Cr–Ni Alloys
Authors: Neding Benjamin , Gorbatov Oleg I. , Tseng Jo-Chi , Hedström Peter
Published: October 2021

The dependence of stacking fault energy (

$${\gamma }_{\text{SFE}}$$

γ
SFE

) on temperature in austenitic Fe–Cr–Ni alloy powders was investigated by in situ high energy synchrotron X-ray diffraction and ab initio calculations in the temperature range from − 45 °C to 450 °C. The X-ray diffraction peak positions were used to determine the stacking fault probability and subsequently the temperature dependence of γ
SFE. The effect of temperature on the diffraction peak positions was found to be mainly reversible; however, recovery of dislocations occurred above about 200 °C, which also gave an irreversible contribution. Two different ab initio-based models were evaluated with respect to the experimental data. The different predictions of the models can be explained by their respective treatment of the magnetic moments for Cr and Ni, which is critical for the alloy compositions investigated. Ab initio calculations, taking longitudinal spin fluctuations (LSF) into consideration within the quasi-classical phenomenological model, predict a temperature dependence of

$${\gamma }_{\rm SFE}$$

γ
SFE

in good agreement with the experimentally evaluated trend of increasing γ
SFE with increasing temperature:

$$\left|\Updelta {\gamma }_{\rm SFE}/\Updelta T\right|=0.05 {\text{mJ}} {\text{m}}^{-2}/{\text{K}}.$$

Δ

γ
SFE

/
Δ
T

=
0.05

mJm

-
2

/
K
.

The temperature effect on γ
SFE is similar for all three investigated alloys: Fe–18Cr–15Ni, Fe–18Cr–17Ni, Fe–21Cr–16Ni (wt pct), while their room temperature

$${\gamma }_{\rm SFE}$$

γ
SFE

are evaluated to be 22, 25, 20 mJ m−2, respectively.
Spatiality of Social Stress Experienced by Refugee Women in Initial Reception Centers
Authors: Nassim Mehran , Jinan Abi Jumaa , Felicia Lazaridou , Naika Foroutan , Andreas Heinz , Ulrike Kluge
Published: October 2021

This study takes an interdisciplinary approach to understanding the multi-dimensionality of social stress within the spatiality of initial refugee reception centers in Berlin. By focusing particularly on the experiences of women who fled from Syria and Afghanistan, it situates this humanitarian issue within an analytical framework of gender-sensitive and culturally sensitive research and policymaking. Through qualitative interviews with 11 refugee women, the connection between the spatiality of initial reception centers and social stress is explored. This is done by thematically coding the data collected in the context of nine different initial reception centers across various districts in the city of Berlin. The study shows that in terms of the intercultural needs and practices of these women, social stress is triggered by a lack of essential privacy within the spatiality of these structures. However, privacy is not limited to a physical enclosure—it is about having control/freedom over different aspects of everyday life. This article highlights intercultural gaps in gender-sensitive and protection considerations during humanitarian responses.
Dispositional and situational moral emotions, bullying and prosocial behavior in adolescence
Authors: Oriol Xavier , Miranda Rafael , Amutio Alberto
Published: October 2021

Studies that distinguish the role of dispositional and situational moral emotions in bullying situations remain limited in the international literature. This work, therefore, aims to analyze the role of dispositional and situational moral emotions in bullying and prosocial behavior in adolescents. Two studies were conducted: a cross-sectional study including 644 adolescents aged 14–18 years (M = 15.6, DT = 1.4) and a repeated measures design including 235 adolescents aged 10–15 years (M = 12.5, DT = 0.9). The objectives of Study 1 were 1) to validate two scales for the situational moral emotions elicited in bullying situations (elevation and moral disgust) and 2) to examine the relationships between dispositional and situational moral emotions and prosocial behavior toward victims and bullying behavior. The results show adequate psychometric properties for both elevation and moral disgust scales. Furthermore, both situational moral emotions are negatively related to bullying behavior, whereas dispositional emotions such as compassion and gratitude have a positive effect on prosocial behavior. Study 2 assessed the prospective relationship between dispositional gratitude and prosocial behavior toward victims and bullying behavior. The results of this study indicate that dispositional gratitude has a positive prospective effect on prosocial behavior towards victims and a negative effect on bullying behavior. In conclusion, the relevance of moral emotions for the prevention of bullying behavior is highlighted and the role that self-transcendent dispositional emotions have on prosocial behavior from the perspective of developmental psychology.
The Basque socioeconomic model (BSEM): a Lonergan perspective
Authors: Hoyt-O’Connor Paul , Cermelli Massimo , Calvo-Sotomayor Inigo
Published: October 2021

Bernard Lonergan maintained that economies are goods of order which, when properly disposed, make possible the regular provision of the material conditions for the fuller flourishing human. Lonergan’s economic thought tried to understand the economy related to a society’s civic institutions, political orders, and cultural traditions. In addition, he wished to explain the normative rhythms of economic development and the conditions of its dynamic equilibrium. In this sense, Lonergan’s analysis presents an alternative to conventional accounts of the kind of economic progress the Basque Country has enjoyed in recent decades, in ways that still resonate with the Basque Country’s emphasis on the centrality of the productive process and the values of its people.
Feature Engineering Techniques and Spatio-Temporal Data Processing
Authors: Forke Chris-Marian , Tropmann-Frick Marina
Published: October 2021

More and more applications nowadays use spatio-temporal data for different purposes. In order to be processed and used efficiently, this unique type of data requires special handling. This paper summarizes methods and approaches for feature selection of spatio-temporal data and machine learning algorithms for spatio-temporal data engineering. Furthermore, it highlights relevant work in specific domains. The range of possible approaches for data processing is quite wide. However, in order to use these approaches with the spatio-temporal data in a meaningful and practical way, individual data processing steps need to be adapted. One of the most important steps is feature engineering.
Knowledge distillation on neural networks for evolving graphs
Authors: Antaris Stefanos , Rafailidis Dimitrios , Girdzijauskas Sarunas
Published: October 2021

Graph representation learning on dynamic graphs has become an important task on several real-world applications, such as recommender systems, email spam detection, and so on. To efficiently capture the evolution of a graph, representation learning approaches employ deep neural networks, with large amount of parameters to train. Due to the large model size, such approaches have high online inference latency. As a consequence, such models are challenging to deploy to an industrial setting with vast number of users/nodes. In this study, we propose DynGKD, a distillation strategy to transfer the knowledge from a large teacher model to a small student model with low inference latency, while achieving high prediction accuracy. We first study different distillation loss functions to separately train the student model with various types of information from the teacher model. In addition, we propose a hybrid distillation strategy for evolving graph representation learning to combine the teacher’s different types of information. Our experiments with five publicly available datasets demonstrate the superiority of our proposed model against several baselines, with average relative drop$$40.60\%$$40.60%in terms of RMSE in the link prediction task. Moreover, our DynGKD model achieves a compression ratio of 21:100, accelerating the inference latency with a speed up factor$$\times 30$$×30, when compared with the teacher model. For reproduction purposes, we make our datasets and implementation publicly available athttps://github.com/stefanosantaris/DynGKD.
The socioeconomic determinants of sustainable residential water consumption in Athens: empirical results from a micro-econometric analysis
Authors: Kostakis Ioannis
Published: October 2021

This paper provides empirical evidence on the effects of socioeconomic characteristics on residential water consumption. The case of Athens is taken as an example for the empirical investigation, using data from the 2019 Household Budget Survey. Employing ordinary, two- and three-stage least squares, seemingly unrelated regression equations and simultaneous quantile specifications, we found that residential water demand is highly price inelastic. Furthermore, empirical results show that water consumption is positively related to household age while more educated households and unemployed persons seem to follow more environmentally friendly behaviour with respect to water demand. Income, gender, house ownership and population density seem to insignificantly affect residential water demand. Our empirical findings might have important national and regional policy implications in the design of sustainable water demand management.
The duty to cooperate in state interactions for the sustainable use of international watercourses
Authors: Oranye Nkechinyelu Patricia , Aremu Abimbola W.
Published: October 2021

The duty to cooperate is a universal principle engrained in International Law. A sequel to this principle is the concept of equitable participation and taking all appropriate measures not to cause significant harm. These principal norms in International Water Law can only function through the cooperation of states. Bilateral and multilateral treaties make this duty a mandatory obligation for contracting parties. Nevertheless, disputes still exist among riparian states over their use of international shared waters. This paper, therefore, seeks to determine how the application of the duty to cooperate in the development of transboundary water can be achieved through the procedural norm of equitable participation and the substantive norm of taking all appropriate measures not to cause significant harm. Through a doctrinal (analytical) approach, empirical studies, as well as the legal framework on international watercourses management will be examined to understand the various roles of states on a transboundary river. The duty to cooperate will also be appraised to ascertain the modalities for its application in International Water Law. This study aims to foster a sustainable pathway to ensuring cooperation in the use of international waters in state interactions. This is relevant for equitable utilization of the waters and their resources.