bluuebunny/crossref_metadata_2025 huggingface dataset:
Obesity and overweight are linked to increased sodium‐glucose cotransporter 1 and glucose transporter 5 levels in duodenum
Authors: Fiorentino Teresa Vanessa , De Vito Francesca , Suraci Evelina , Marasco Raffaella , Hribal Marta Letizia , Luzza Francesco , Sesti Giorgio
Published: February 2023

Objective

Prior evidence indicates that individuals with obesity have an accelerated intestinal glucose absorption. This cross‐sectional study evaluated whether those with overweight or obesity display higher duodenal protein levels of the glucose carriers sodium‐glucose cotransporter 1 (SGLT‐1), glucose transporter 2 (GLUT‐2), and glucose transporter 5 (GLUT‐5).

Methods

SGLT‐1, GLUT‐2, and GLUT‐5 protein levels were assessed on duodenal mucosa biopsies of 52 individuals without diabetes categorized on the basis of their BMI as lean, with overweight, or with obesity.

Results

Individuals with overweight and obesity exhibited progressively increased duodenal protein levels of SGLT‐1 and GLUT‐5 as compared with the lean group. Conversely, no differences in duodenal GLUT‐2 abundance were found among the three groups. Univariate analysis showed that SGLT‐1 and GLUT‐5 protein levels were positively correlated with BMI, waist circumference, 1‐hour post‐load glucose, fasting and post‐load insulin, and insulin secretion and resistance levels. Furthermore, a positive relationship was detected between intestinal GLUT‐5 levels and serum uric acid concentrations, a product of fructose metabolism known to be involved in the pathogenesis of obesity and its complications.

Conclusions

Individuals with overweight and obesity display enhanced duodenal SGLT‐1 and GLUT‐5 abundance, which correlates with increased postprandial glucose concentrations, insulin resistance, and hyperinsulinemia.
Investigating the use of natural hollow fibers from common milkweed to improve the mechanical and thermal properties of epoxy resin
Authors: Sanchez‐Diaz Simon , Ouellet Carl , Elkoun Saïd , Robert Mathieu
Published: February 2023

Milkweed floss was used as a reinforcement to develop lightweight epoxy composites with enhanced thermal insulating properties. Seed fibers fromAsclepias Syriacaharvested in Quebec were used for this study. Some fibers were treated with acetone to remove their protective hydrophobic coating. Epoxy resin was blended with 15% w/w of native or acetone‐treated milkweed floss to form prepregs. The prepregs were casted into molds, degassed, and compressed to produce the composites. The composites were passed through a post‐curing phase before characterization. The composites and the epoxy resin alone were characterized to determine their density, porosity, thermal conductivity, thermal degradation, mechanical resistance, and thermo‐mechanical behavior. The composites reinforced with native or acetone‐treated milkweed floss were 7.4% and 10.3% lighter than the epoxy resin, respectively. The specific elastic modulus of the resin increased by 9.6% and 20.1% with the addition of native or acetone‐treated fibers, respectively. The thermal conductivity of the epoxi decreased by 7.8% and 15.6% with the use of native or acetone‐treated milkweed floss, respectively. Due to their low weight and reduced thermal conductivity, the milkweed‐reinforced epoxy composites may find applications in the production of structural and insulating elements for vehicles and buildings.
Qualitative and quantitative contaminants assessment in recycled pellets from post‐consumer plastic waste by means of spectroscopic and thermal characterization
Authors: Cozzarini Luca , Marsich Lucia , Ferluga Alessio
Published: February 2023

The complexity of any plastic recycling initiative lies in the heterogeneous nature of the post‐consumer commingled plastic waste stream: recycling treatments are challenging without prior reliable sorting. A suitable identification system should be able to recognize different plastics and blends. Nowadays, the main technique used as quality control in plastic waste sorting centers is differential scanning calorimetry, whose result can be purely qualitative or semi‐quantitative, since only the crystalline fraction is evaluated. Moreover, the time required for data acquisition is relatively long. Infrared spectroscopy is an alternative, faster technique extensively used in applied research, but not widely utilized in industry. In this work, the cross‐use of infrared spectroscopy and calorimetry is tested in a real, practical case: the quality control of recycled pellets (namely composed of polyolefins only), which represent the output of a commingled plastic recycling plant and are used as secondary raw materials for different applications. Appropriate infrared spectroscopy calibration curves were built to allow the quantitative analysis with respect to the most common polymers found in the commingled plastic waste stream; the composition and contaminants in the recycled pellets were thereby determined and tracked through different production batches through the cross‐use of the two techniques outlined above.
Targeting lipid metabolism with natural products: A novel strategy for gastrointestinal cancer therapy
Authors: Guo Cui , Zhang Lanlan , Zhao Maoyuan , Ai Yanling , Liao Wenhao , Wan Lina , Liu Qingsong , Li Songtao , Zeng Jinhao , Ma Xiao , Tang Jianyuan
Published: February 2023

Gastrointestinal cancer (GIC), including gastric cancer and colorectal cancer, is a common malignant tumor originating from gastrointestinal epithelial cells. Although the pathogenesis of GIC remains unclear, aberrant lipid metabolism has emerged as a hallmark of cancer. Several enzymes, proteins, and transcription factors are involved in lipid metabolism reprogramming in GIC, and their abnormal expression can promote lipid synthesis and accumulation of lipid droplets through numerous mechanisms, thereby affecting the growth, proliferation, and metastasis of GIC cells. Studies show that some natural compounds, including flavonoids, alkaloids, and saponins, can inhibit the de novo synthesis of lipids in GIC, reduce the level of lipid accumulation, and subsequently, inhibit the occurrence and development of GIC by regulating Sterol regulatory element‐binding protein 1 (SREBP‐1), adenosine monophosphate‐activated protein kinase (AMPK), 3‐hydroxy‐3‐methylglutaryl‐coenzyme A reductase (HMGCR), phosphatidylinositol‐3‐kinase/Akt and the mammalian target of rapamycin PI3K/Akt/mTOR, amongst other targets and pathways. Therefore, targeting tumor lipid metabolism is the focus of anti‐gastrointestinal tumor therapy. Although most natural products require further high‐quality studies to firmly establish their clinical efficacy, we review the potential of natural products in the treatment of GIC and summarize the application prospect of lipid metabolism as a new target for the treatment of GIC, hoping to provide a reference for drug development for gastrointestinal tumors.
Two cases of large tracheobronchial schwannomas completely resected by rigid bronchoscopy with multiple instruments
Authors: Kim Changhwan , Nam Hae‐Seong , Ko Yousang
Published: February 2023

Primary tracheobronchial schwannomas are extremely rare. Surgical treatment has been the first choice for these benign tumours due to the substantial residual rates and recurrences after bronchoscopic resection. In addition, there has been limited information on bronchoscopic removal of endobronchial schwannomas. We describe two cases of large tracheal and bronchial schwannomas that were completely and successfully resected by snare electrocautery, insulation‐tipped knife, and argon plasma coagulation under rigid bronchoscopy. These cases highlight that rigid bronchoscopic treatment with these multiple instruments can be a good treatment option for endotracheal or endobronchial schwannomas.
Effect of annealing temperature on structural, optical, and photocatalytic properties of modified sol–gel‐driven ZnO nanoparticles
Authors: Ayon Sikder Ashikuzzaman , Billah Md Muktadir , Hossain Mohammad Nazmul
Published: February 2023

ZnO nanoparticles (NPs) were synthesized in this study using a modified sol–gel route. Synthesized NPs were annealed at various temperatures, namely, 400, 500, 600, and 700°C, to optimize annealing temperature to make the NPs suitable for photocatalytic application. The hexagonal wurtzite structure was revealed by XRD analysis for all NPs, and the crystallinity showed an increase when the annealing temperature was increased. Rietveld analysis was conducted to measure the lattice parameters, crystallite size, and microstrain of the NPs. Micro‐strain showed a decrease with increasing annealing temperature. The size of particles showed an increase with increasing annealing temperature, which was evident from the morphological analysis by SEM. Later, activation energy calculated from Scott's equation also revealed differential crystal growth rates with increasing annealing temperatures. Bandgap was found to decrease with increasing annealing temperature as well. XPS confirms the phase purity and the charge states of NPs. Rhodamine B (RhB) was used to measure photocatalytic degradation efficiency and superior photocatalytic degradation was found for 500°C.
Quantum mechanics and Alexander Bogdanov's worldview: A conversation
Authors: Rovelli Carlo , Jackson Michael C.
Published: February 2023

This paper is a transcript of the dialogue between Carlo Rovelli and Mike Jackson after Rovelli's delivery of the 2021 Annual Mike Jackson Lecture, hosted by the Centre for Systems Studies at the University of Hull. The dialogue covers a range of topics, including how Rovelli developed a sense of curiosity in his youth; the connection between his interests in science and politics; the pathology of disciplinary divisions in academia; the value of Bogdanov's transdisciplinarity; Rovelli's theory of quantum gravity; the notions of granularity, indeterminism and relationality underpinning quantum mechanics; the role of the observer; mistaken uses of quantum mechanics; relational and network views of the world; how the discipline of Physics is becoming more systemic; the concept of levels of analysis in relation to nature and human inquiry; and the future for humanity.
Context-Specific Issues and Challenges of Policing in the Pacific
Authors: Watson Danielle , Howes Loene , Dinnen Sinclair , Bull Melissa , Amin Sara N.
Published: February 2023

Issues and challenges are not uncommon to policing organisations across the globe. For those in Pacific Islands countries and territories (PICTs), common issues such as functioning in a limited or resource-constrained environment and adapting to continuously increasing stakeholder demands are further compounded by geographic context. The region presents unique policing spaces, which means that policing challenges characterised as normal or conventional must be dealt with alongside unconventional policing issues specific to PICTs with varied governance arrangements, strained resources, diverse cultures and traditions, reliance on external support, spaces that are policed by alternative means, and large and often fragmented jurisdictions. This chapter provides an overview of the challenges faced by police organisations in PICTs and shows that policing in these contexts is as much about improvisation as it is about discretion and professional practice. It establishes a context for later discussions about crime in PICTs; formal and informal policing roles across the region underscored by geography, tradition, culture, and religion; international policing agendas; and contemporary shifts in arguments about women in policing.
Conclusion
Authors: Watson Danielle , Howes Loene , Dinnen Sinclair , Bull Melissa , Amin Sara N.
Published: February 2023

Police organisations of the Pacific reflect the diversity and complexity of the countries and territories of the region, in terms of their size and the legitimacy and technical capabilities of these relatively young states. This short concluding chapter reflects upon the issues faced by Pacific Island policing organisations as discussed in previous chapters. It acknowledges the challenges police face in negotiating with diverse sources of authority and multiple actors in domestic settings and international settings, as well as the increasing vulnerability of Pacific Island countries and territories to transnational crime and insecurity produced through global mobility and communications technology, and the implications of changing gender dynamics on policing across the region. The chapter calls for further research on Pacific policing that adopts indigenous methodologies, community participation, and stakeholder partnerships to inform appropriately nuanced and contextualised policy and action on policing in the Pacific Islands.
Embedding of the Georgi-Glashow SU(5) model in the superconformal algebra
Authors: Alvarez P. D. , Chavez R. A. , Zanelli J.
Published: February 2023

Abstract

We present a scheme to construct grand unified models based on the superconformal algebra and the inclusion of matter fields in the adjoint representation of supersymmetry. As an illustration, we implemented the Georgi-Glashow SU(5) model. The model predicts the existence of a dark (1,24, 0) + (5,5*, −y′) + (5*,5, y′) sector and an anomalous U(1)Z.
On the rank of general linear series on stable curves
Authors: Christ Karl
Published: February 2023

We study the dimension of loci of special line bundles on stable curves and for a fixed semistable multidegree. In case of total degree $$d = g - 1$$

d
=
g
-
1

, we characterize when the effective locus gives a Theta divisor. In case of degree $$g - 2$$

g
-
2

and g, we show that the locus is either empty or has the expected dimension. This leads to a new characterization of semistability in these degrees. In the remaining cases, we show that the special locus has codimension at least 2. If the multidegree in addition is non-negative on each irreducible component of the curve, we show that the special locus contains an irrreducible component of expected dimension.
A catastrophe theory-based model for optimal control of chemical reactions by means of oriented electric fields
Authors: Bofill Josep Maria , Quapp Wolfgang , Albareda Guillem , Moreira Ibério de P. R. , Ribas-Ariño Jordi , Severi Marco
Published: February 2023

The effect of oriented external electric fields (OEEF) on chemical reactivity has been studied theoretically and computationally in the last decades. A central goal in this research area is to predict the orientation and the smallest amplitude electric field that renders a barrierless chemical process with the smallest possible strength. Recently, a model to find the optimal electric field has been proposed and described (Bofill JM et al., J. Chem. Theory Comput. 18:935, 2022). We here proof that this model is based on catastrophe and optimum control theories. Based on both theories a technical treatment of the model is given and applied to a two-dimensional generic example that provides insight into its nature and capability. Finally, the model is applied to determine the optimal OEEF for the trans-to-cis isomerization of a [3]cumulene derivative.
Flaxseed mucilage/calcium phosphate composites as bioactive material for bone tissue regeneration
Authors: Salama Ahmed , Saleh Safaa , Abou-Zeid Ragab E. , Akl Engy M. , Tolba Emad
Published: February 2023

Biocompatible polymers are attractive material for the manufacturing of surgical implants which break down in vivo without the necessity for a consequent operation for removal. Elaboration of composite biomaterials scaffolds as artificial bone graft materials remains a major task in bioengineering. Flaxseed mucilage was used as bioactive polysaccharide for preparing composite scaffolds made of calcium phosphate embedded in mucilage matrix. Calcium chloride was mixed with mucilage followed by the addition of phosphate precursor to stimulate the in situ formation of calcium phosphate. The obtained scaffolds mucilage/calcium phosphate at different pHs (5 and 8) were characterized using FTIR, XRD, TGA, SEM/EDX and TEM. The results showed the formation of two phases: mucilage/dicalcium phosphate dihydrate (MU/brushite) and mucilage/hydroxyapatite (MU/HA). MTT test was applied to evaluate viability of MC3T3-E1 osteoblasts cells, and the formed hybrids at various pH conditions were classified as non-cytotoxic. These findings establish the potential of developed composite to be used as bone graft substitute materials.
Time series radiomics for the prediction of prostate cancer progression in patients on active surveillance
Authors: Sushentsev Nikita , Rundo Leonardo , Abrego Luis , Li Zonglun , Nazarenko Tatiana , Warren Anne Y. , Gnanapragasam Vincent J. , Sala Evis , Zaikin Alexey , Barrett Tristan , Blyuss Oleg
Published: February 2023

Serial MRI is an essential assessment tool in prostate cancer (PCa) patients enrolled on active surveillance (AS). However, it has only moderate sensitivity for predicting histopathological tumour progression at follow-up, which is in part due to the subjective nature of its clinical reporting and variation among centres and readers. In this study, we used a long short-term memory (LSTM) recurrent neural network (RNN) to develop a time series radiomics (TSR) predictive model that analysed longitudinal changes in tumour-derived radiomic features across 297 scans from 76 AS patients, 28 with histopathological PCa progression and 48 with stable disease. Using leave-one-out cross-validation (LOOCV), we found that an LSTM-based model combining TSR and serial PSA density (AUC 0.86 [95% CI: 0.78–0.94]) significantly outperformed a model combining conventional delta-radiomics and delta-PSA density (0.75 [0.64–0.87]; p = 0.048) and achieved comparable performance to expert-performed serial MRI analysis using the Prostate Cancer Radiologic Estimation of Change in Sequential Evaluation (PRECISE) scoring system (0.84 [0.76–0.93]; p = 0.710). The proposed TSR framework, therefore, offers a feasible quantitative tool for standardising serial MRI assessment in PCa AS. It also presents a novel methodological approach to serial image analysis that can be used to support clinical decision-making in multiple scenarios, from continuous disease monitoring to treatment response evaluation.

Key Points

•LSTM RNN can be used to predict the outcome of PCa AS using time series changes in tumour-derived radiomic features and PSA density.

•Using all available TSR features and serial PSA density yields a significantly better predictive performance compared to using just two time points within the delta-radiomics framework.

•The concept of TSR can be applied to other clinical scenarios involving serial imaging, setting out a new field in AI-driven radiology research.
Association between periodontitis and breast cancer: two-sample Mendelian randomization study
Authors: Ding Ming , Zhang Zhonghua , Chen Zhu , Song Jukun , Wang Beichuan , Jin Fuqian
Published: February 2023

Objectives

The purpose of this study was to investigate whether there is a causal relationship between periodontitis and breast cancer by Mendelian randomization analysis.

Materials and methods

We performed a two-sample bidirectional Mendelian randomization (MR) analysis using publicly released genome-wide association studies (GWAS) statistics. The inverse-variance weighted (IVW) method was used as the primary analysis. We applied complementary methods, including weighted median, weighted mode, simple mode, MR-Egger regression, and MR-pleiotropy residual sum and outlier (MR-PRESSO) to detect and correct for the effect of horizontal pleiotropy.

Results

IVW MR analysis showed no effect of periodontitis on breast cancer (IVW OR=0.99, P =0.14). Similarly, no significant causal relationship between breast cancer and periodontitis was found in reverse MR analysis (IVW OR=0.95, P =0.83). The results of MR-Egger regression, weighted median, and weighted mode methods were consistent with those of the IVW method. Based on sensitivity analyses, horizontal pleiotropy is unlikely to distort causal estimates.

Conclusions

Although observational studies have reported an association between periodontitis and breast cancer, the results of our MR analysis do not support a causal relationship between periodontitis and breast cancer.

Clinical relevance

Mendelian randomization study can more clearly analyze the causal relationship between periodontitis and breast cancer, in order to provide a certain reference for clinicians and deepen the understanding of the relationship between periodontitis and breast cancer, to explore more possible associations between periodontitis and systemic diseases.
The Renaissance of Mixed Forests? New Insights Into Shifts in Tree Dominance and Composition Following Centuries of Human-induced Simplification of Iberian Forests
Authors: Sánchez de Dios Rut , DeSoto Lucía , Cortón Blanca , Hernández Laura
Published: February 2023

Anthropic activities have modelled and simplified southern European forest landscapes for centuries. Over recent decades, new drivers related to human-mediated global change have induced the redistribution of tree species and an increase in more complex forests. However, the current large-scale patterns and drivers of these changes are yet to be fully described for the Mediterranean Basin. In this frame, this work identifies and examines changes in dominance and composition from pure to mixed forests across bioclimatic gradients and forest types in Iberian forests over recent decades based on data from the Spanish National Forest Inventory from 1960 to 2020. Then, considering different environmental, anthropic, and disturbance variables we also identify some of the most important drivers associated with the shifts observed from 1986 to 2020. Our results confirm an ongoing increase in mixed forests involving the replacement of conifers by broadleaved species. These shifts are greater in the Atlantic biogeoregion and in pure broadleaved deciduous forests. Climate warming-associated disturbances such as drought severity together with land use legacies and forest types showed the strongest relationships with the observed changes in the studied forests. Our results support the premise put forward by palaeoecologists which states that the increase in tree mixtures is a natural process reversing the historical human-induced simplification of Iberian forests. The increasing importance of mixed forest in southern Europe makes decisive the revision of forest classifications as well as forest management and conservation plans in order to include these increasingly abundant novel stands in forest policies.
A dynamic causal modeling of the second outbreak of COVID-19 in Italy
Authors: Bilancia Massimo , Vitale Domenico , Manca Fabio , Perchinunno Paola , Santacroce Luigi
Published: February 2023

While the vaccination campaign against COVID-19 is having its positive impact, we retrospectively analyze the causal impact of some decisions made by the Italian government on the second outbreak of the SARS-CoV-2 pandemic in Italy, when no vaccine was available. First, we analyze the causal impact of reopenings after the first lockdown in 2020. In addition, we also analyze the impact of reopening schools in September 2020. Our results provide an unprecedented opportunity to evaluate the causal relationship between the relaxation of restrictions and the transmission in the community of a highly contagious respiratory virus that causes severe illness in the absence of prophylactic vaccination programs. We present a purely data-analytic approach based on a Bayesian methodology and discuss possible interpretations of the results obtained and implications for policy makers.
Sex Education in Italy: An Overview of 15 Years of Projects in Primary and Secondary Schools
Authors: Lo Moro Giuseppina , Bert Fabrizio , Cappelletti Toni , Elhadidy Heba Safwat Mhmoued Abdo , Scaioli Giacomo , Siliquini Roberta
Published: February 2023

School-based sex education is essential to improve the knowledge and behavior of young people. Unlike most European countries, sex education in Italy is not compulsory in the school curriculum. Therefore, to assess potential gaps, the main aim of this study was to explore Italian regional initiatives about sex education. A review of gray literature from 2006 to 2021 was conducted in December 2021 on national databases and institutional websites of each Italian region, during which official documents on regional sex education programs were selected. Moreover, a rapid systematic review was carried out in scientific databases to find more information. For both reviews, the sex education topics recommended by UNESCO were used for extracting and analyzing data. A total of 12 Italian regions out of 20 had at least one sex education program, for a total of 39 projects. Overall, all the topics identified by UNESCO have been covered, with considerable differences between northern, central, and southern Italy. Contraception, love, marriage, partnerships, and family were the main topics discussed (hosted in 92% of the regions). Only 25% of the regions discussed pregnancy and birth. Disability was the least debated topic (17%). The rapid systematic review showed that relevant improvements were achieved after sex education interventions. In conclusion, this study underlined important limitations to the implementation of school-based sex education in Italy. Hence, it is necessary to increase sex education interventions to reach adequate standards and flatten the differences not only between Italian regions but also between Italy and other European countries.
Optimal control problems with $$L^0(\Omega )$$ constraints: maximum principle and proximal gradient method
Authors: Wachsmuth Daniel
Published: February 2023

We investigate optimal control problems with $$L^0$$

L
0

constraints, which restrict the measure of the support of the controls. We prove necessary optimality conditions of Pontryagin maximum principle type. Here, a special control perturbation is used that respects the $$L^0$$

L
0

constraint. First, the maximum principle is obtained in integral form, which is then turned into a pointwise form. In addition, an optimization algorithm of proximal gradient type is analyzed. Under some assumptions, the sequence of iterates contains strongly converging subsequences, whose limits are feasible and satisfy a subset of the necessary optimality conditions.
We Are Displaced, But We Are More Than That: Using Anarchist Principles to Materialize Capitalism’s Cracks at Sites of Contemporary Forced Displacement in Europe
Authors: Kiddey Rachael
Published: February 2023

This article charts the development of The Made in Migration Collective, a coalition of displaced people, academics, and creative professionals that was developed during a recently completed British Academy postdoctoral fellowship. Following discussion of how archaeology and heritage are under attack globally from far-right nationalism and specifically within the UK, I provide examples of how community archaeology can highlight fissures in capitalism. I follow others in interpreting anarchism as a potential form of care. Two public heritage exhibitions – one digital, one “live”—which were collaboratively produced by The Made in Migration Collective are reflected upon.
Co-Developmental Trajectories of Parental Psychological Distress and Child Internalizing and Externalizing Problems in Childhood and Adolescence: Associations with Self-Harm and Suicide Attempts
Authors: Zhu Xinxin , Griffiths Helen , Murray Aja Louise
Published: February 2023

Growing evidence has suggested that parental mental illness and child internalizing and externalizing problems tend to co-occur and engender risk for adverse child outcomes; however, there is considerable heterogeneity in their joint developmental trajectories. This study aimed to evaluate the joint developmental trajectories of maternal and paternal psychological distress and child internalizing and externalizing problems from early childhood to middle adolescence. Given that suicide and self-harm are major public health issues in adolescence and often occur in the context of other mental health issues, we also examined the association between these joint trajectories and these outcomes in adolescence. Parallel-process latent class growth analysis was applied to 14 years of follow-up data from a large-scale, nationally representative sample of youths participating in the UK’s Millennium Cohort Study (MCS; n = 12,520, 50.9% male). Results showed the best-fitting solution had four trajectory classes: (1) low symptoms, 59.0%; (2) moderate symptoms in children, 22.5%; (3) notable symptoms in fathers, 10.7%; and (4) co-occurring maternal and child symptoms, 7.8%. The trajectory groups differed in their self-harm and suicide attempts in adolescence, underscoring the possible importance of the roles of both parental distress and child problem behaviors processes in these outcomes. Future studies will be valuable to rigorously test the directionality and the respective roles of parents and children in this association. Our findings suggest the need for two-generation mental health intervention programs that are tailored based on co-developmental trajectory group membership.
The profile of extreme tension wave front in aluminum
Authors: Lim Seokbin , Kennedy James , Chavira Angel , Hirsch Matthew , Wei Tie , Ryu Donghyeon
Published: February 2023

In this study, the extreme tension wave front profile (pull speed up to 1.6 km/s) in pure aluminum (density 2.7 $$\mathrm{g}/{\mathrm{cm}}^{3}$$

g
/

cm

3

) is analyzed using the LAMMPS molecular dynamics (MD) code and based on the tension conservation equations of mass, momentum, and energy. The simulation results agree favorably with the theoretical calculation. The profile of the extreme tension wave front is observed from the MD code simulation, and a typical shockless ramp wave front formation is identified during forced extreme tension loading. Further analysis was accomplished based on the formation of the ramp wave front, illustrating the behavior of the isentrope of aluminum under extreme tension loading.
Superfluid Drain Vortex
Authors: Ruffenach Wandrille , Galantucci Luca , Barenghi Carlo F.
Published: February 2023

Drain vortices are among the most common vortices observed in everyday life, yet their physics is complex due to the competition of vorticity’s transport and diffusion, and the presence of viscous layers and a free surface. Recently, it has become possible to study experimentally drain vortices in liquid helium II, a quantum fluid whose physics is characterised by the absence of viscosity and the quantisation of the circulation in the superfluid component. Using the Gross–Pitaevskii equation, we make a simple model of the problem which captures the essential physics ingredients, showing that the drain vortex of a pure superfluid consists of a bundle of vortex lines which, in the presence of a radial drain, twist, thus strengthening the axial flow into the drain.
Ultrasonic and Impact-Echo Testing for the Detection of Scaling in Geothermal Pipelines
Authors: Stüwe Isabelle , Zacherl Lilly , Grosse Christian U.
Published: February 2023

The efficiency and longevity of components in geothermal plants are significantly reduced by mineral deposition in pipes, also known as scaling [1]. A number of methods are used to monitor fouling (a broader term for all types of organic and inorganic deposition) in other industries, such as the oil, gas and food industries. These include direct and indirect, offline, in-situ and online, as well as inline methods, each of which have pros and cons [2, 3]. An effective monitoring solution specific to the high temperature conditions in geothermal plants, which optimises maintenance and cleaning measures in dependency of scaling, has yet to be developed. In this paper, two non-destructive testing techniques: contact ultrasonic testing (UT) and impact-echo (IE) testing are investigated in their viability as methods to detect scaling growth in geothermal plants. A descaling measurement was conducted on a heavily scaled segment of an obsolete pipeline from the production well of the geothermal power plant in Sauerlach, Germany. The pipeline segment was inserted in a test rig and the scaling was gradually etched away using an acidic solution. At regular time intervals, the scaling thickness was measured mechanically and contact UT as well as IE measurements were carried out. The testing apparatus was designed to withstand high temperatures ($${140}\,^{\circ }{\text {C}}$$140∘Cat the inlet pipe surface) and to be easy to install whilst being cost-efficient. Both techniques yielded usable results with submillimeter resolution. The advantages and limitations of the two methods are discussed. Impact-echo testing, in particular, can be automated and presents a simple and cost-efficient scaling monitoring option.
Addressing Ethnic Differences in the Validity of Self-reported Criminal Behaviour Through a Social Desirability Measure
Authors: Bezemer Willemijn E. , Born Marise Ph. , Leerkes Arjen S.
Published: February 2023

Objectives

Self-reported criminal behaviour has the potential to provide clearer insights into patterns of criminality compared to using police statistics. The risk of inaccurate responses however forms a major obstacle to its validity. This study therefore examines underreporting bias of self-reported criminal behaviour among five ethnic groups and compares different methods to facilitate the creation of valid intergroup comparisons.

Methods

This study includes data from the Monitor on Youthful Delinquency (N = 6,218) which was connected to police suspect registrations. To identify patterns of underreporting, we compared self-reported and police recorded crime with a social desirability measure, which was adjusted to be invariant across ethnic groups. Three different methods to correct for underreporting bias were subsequently compared; partialling out the effect of social desirability, listwise deletion, and a novel technique which we named Social Desirability based Score Replacement (SDSR).

Results

The study reveals that police suspects with a high social desirability score display a low likelihood to self-report crime when they have an ethnic minority background, but not when they have a native Dutch background or when they have a moderate to low social desirability score. This finding points towards systematic differences in underreporting bias. Model outcomes are shown to be significantly impacted depending on the method that is used to address this issue.

Conclusion

Neglecting to correct underreporting-bias hinders the validity of intergroup comparisons of self-reported criminal behaviour. The inclusion of a social desirability measure is therefore recommended to help identify and correct underreporting bias, particularly through the use of SDSR.
Consistent Theories in Inconsistent Logics
Authors: Mangraviti Franci , Tedder Andrew
Published: February 2023

The relationship between logics with sets of theorems including contradictions (“inconsistent logics”) and theories closed under such logics is investigated. It is noted that if we take “theories” to be defined in terms of deductive closure understood in a way somewhat different from the standard, Tarskian, one, inconsistent logics can have consistent theories. That is, we can find some sets of formulas the closure of which under some inconsistent logic need not contain any contradictions. We prove this in a general setting for a family of relevant connexive logics, extract the essential features of the proof in order to obtain a sufficient condition for the consistency of a theory in arbitrary logics, and finally consider some concrete examples of consistent mathematical theories in Abelian logic. The upshot is that on this way of understanding deductive closure, common to relevant logics, there is a rich and interesting kind of interaction between inconsistent logics and their theories. We argue that this suggests an important avenue for investigation of inconsistent logics, from both a technical and a philosophical perspective.
Seismic forward modeling of acoustic surface-related order-separated multiples
Authors: Wang Zhong-Sheng , Su Wu-Que , Li Yong-Xin , Li Zhong-Sheng , Hu Jing
Published: February 2023

Seismic surface-related multiples have become a hot topic of great significance due to the buried geological information provided by broader illumination areas than primaries. In recent years, researchers attempt to extract the hidden hint of multiples rather than treating them as noise and eliminating them directly. The elimination methods, e.g., the surface-related multiple elimination (SRME) and the inverse scattering series free-surface multiple elimination (ISS-FSME), may be affected by the overlapping or proximity of primaries and multiples. Typical imaging methods, e.g., the reverse time migration (RTM) and the least-square reverse time migration (LSRTM), suffer severe crosstalk artifacts from multiples of inappropriate order and smooth migration velocities. To study the characteristics of primaries and surface-related multiples, whether for elimination or imaging, we propose a forward modeling method of acoustic surface-related order-separated multiples established on the areal/virtual source assumption. The free surface is replaced with an absorbing surface under the dipole source approximation and the ghost creation approach. We present two reflection operators to approximate the reflection at the free surface and apply them to the areal source to obtain ideal results. Numerical experiments on three models prove the effectiveness of the proposed forward modeling method of acoustic surface-related order-separated multiples.
Multibody dynamics and optimal control for optimizing spinal exoskeleton design and support
Authors: Harant Monika , Näf Matthias B. , Mombaur Katja
Published: February 2023

In the industrial work environment, spinal exoskeletons can assist workers with heavy lifting tasks by reducing the needed muscle activity. However, the requirements for the design and control of such an exoskeleton to optimally support users with different body builds and movement styles are still open research questions. Thus, extensive testing on the human body is needed, requiring a lot of different sophisticated prototypes that subjects can wear for several hours. To facilitate this development process, we use multibody dynamics combined with optimal control to optimize the support profile of an existing prototype and evaluate a new design concept (DC) that includes motors at the hip joint. A dynamic model of the prototype was developed, including its passive elements with torque generation that accounts for potential misalignment. The human-robot interaction was simulated and optimized in an all-at-once approach. The parameters that describe the characteristics of the passive elements (including beam radius, spring pretension, length of the lever arm, radius of profile) and, in the case of DC, the torque profiles of the motors were optimized. Limits on interaction forces ensured that the exoskeleton remains comfortable to wear. Simulations without the exoskeleton allowed comparing the user’s actuation concerning joint moment and muscle activation. Our results agree well with experimental data using the prototype, making it a useful tool to optimize exoskeleton design and support and evaluate the effect of different actuation systems, mass distributions, and comfort requirements.
Efficient simulation strategy to design a safer motorcycle
Authors: Maier Steffen , Fehr Jörg
Published: February 2023

This work presents models and simulations of a numerical strategy for a time and cost-efficient virtual product development of a novel passive safety restraint concept for motorcycles. It combines multiple individual development tasks in an aggregated procedure. The strategy consists of three successive virtual development stages with a continuously increasing level of detail and expected fidelity in multibody and finite element simulation environments. The results show what is possible with an entirely virtual concept study—based on the clever combination of multibody dynamics and nonlinear finite elements—that investigates the structural behavior and impact dynamics of the powered two-wheeler with the safety systems and the rider’s response. The simulations show a guided and controlled trajectory and deceleration of the motorcycle rider, resulting in fewer critical biomechanical loads on the rider compared to an impact with a conventional motorcycle. The numerical research strategy outlines a novel procedure in virtual motorcycle accident research with different levels of computational effort and model complexity aimed at a step-by-step validation of individual components in the future.
Bioimpedance basics and phase angle fundamentals
Authors: Ward Leigh C. , Brantlov Steven
Published: February 2023

Measurement of phase angle using bioimpedance analysis (BIA) has become popular as an index of so-called “cellular health”. What precisely is meant by this term is not always clear but strong relationships have been found between cellular water status (the relative amounts of extra- and intracellular water), cell membrane integrity and cellular mass. Much of the current research is empirical observation and frequently pays little regard to the underlying biophysical models that underpin the BIA technique or attempts to provide mechanistic explanations for the observations. This brief review seeks to provide a basic understanding of the electrical models frequently used to describe the passive electrical properties of tissues with particular focus on phase angle. In addition, it draws attention to some practical concerns in the measurement of phase angle and notes the additional understanding that can be gained when phase angle are obtained with bioimpedance spectroscopy (BIS) rather than single frequency BIA (SFBIA) along with the potential for simulation modelling.
A New Global Nonlinear Force-Free Coronal Magnetic-Field Extrapolation Code Implemented on a Yin–Yang Grid
Authors: Koumtzis Argyrios , Wiegelmann Thomas
Published: February 2023

The solar magnetic field dominates and structures the solar coronal plasma. Detailed insights into the coronal magnetic field are important to understand most physical phenomena there. While direct, routine measurements of the coronal magnetic field are not available, field extrapolation of the photospheric vector-field measurements into the corona is the only way to study the structure and dynamics of the coronal field. Here we focus on global coronal structures traditionally modeled using spherical grids and synoptic vector magnetograms as boundary conditions. We developed a new code that performs nonlinear force-free magnetic-field extrapolations in spherical geometry. Our new implementation is based on a well-established optimization principle on a Cartesian grid and a single spherical finite-difference grid. In the present work, for the first time, the algorithm is able to reconstruct the magnetic field in the entire corona, including the polar regions. The finite-difference numerical scheme that was employed in previous spherical-code versions suffered from numerical inefficiencies because of the convergence of those grids on the poles. In our new code, we implement the so-called Yin–Yang overhead grid, the structure of which addresses this difficulty. Consequently, both the speed and accuracy of the optimization algorithm are improved compared to the previous implementations. We tested our new code using the well known semi-analytical model (Low and Lou solution). This is a commonly used benchmark for nonlinear force-free extrapolation codes.
Strategising PhD supervision in Ukrainian higher education
Authors: Hladchenko Myroslava
Published: February 2023

This article explores the implications of the national, organisational and individual cultural dimensions for the strategies of PhD supervisors. The intended outcome of PhD supervision is considered to be a doctoral graduate with advanced research skills as well as an original contribution to knowledge production. Data emanate from the interviews with 12 doctoral supervisors from several disciplines affiliated with one of the leading Ukrainian universities. The PhD supervisors were interviewed in April-June 2018. The study findings indicate that, firstly, institutional and cultural complexities which refer to the lack of favourable conditions for doctoral supervision hinder PhD supervisors from achieving the intended outcome. Secondly, the strategic goals and adopted courses of action of PhD supervisors also depend on their values, beliefs, knowledge and skills and if they are unrelated to the intented outcome of PhD supervision it hinders the PhD candidates from acquiring advanced research skills as well as making an original contribution to knowledge production.
Educating Engineering Students to Address Bias and Discrimination Within Their Project Teams
Authors: Isaac Siara , Kotluk Nihat , Tormey Roland
Published: February 2023

What training should engineering students receive to enable them to contribute to reducing bias, discrimination and the persistent lack of diversity in engineering? Collaboration is central to professional engineering work and, consequently, teamwork and group projects are increasingly present in engineering curricula. However, the influence of unconscious bias on interactions within teams can negatively affect women and underrepresented groups and is now recognised as an important engineering ethics issue. This paper describes a workshop designed to enable engineering students to work equitably in diverse teams. Key features of the workshop include (1) the emotionally safe, empowering and warm environment created, (2) the creation of opportunities for students to discuss and apply the issues raised to their own engineering projects, and (3) the opportunities to practice the use of both proactive and reactive strategies to address bias and discrimination in teams. The evaluation of the workshop suggests that engineering students regarded both onsite and online formats as providing useful skills that they intended to apply in practice. Follow-up evaluations suggest that the workshop leads to behavioural change, especially the use of proactive teamwork strategies intended to reduce the impact of unconscious bias.
Informal Care and Subjective Well-Being among Older Adults in Selected European Countries
Authors: Abramowska-Kmon Anita , Łątkowski Wojciech , Rynko Maja
Published: February 2023

A person’s health status is one of the strongest determinants of well-being. The negative impact of poor health on subjective well-being may be moderated by providing care to individuals in need. In this paper, we investigate the relationships between receiving informal care and the amount of care received and subjective well-being among people aged 65 or older in selected European countries. Our analysis of data from the 6th wave of the Survey of Health, Ageing and Retirement in Europe (SHARE) showed that receiving regular informal care was associated with higher subjective well-being among older people in Northern European countries, and with lower subjective well-being among older males in Southern European countries. Moreover, we found that the perception of the amount of help received affected the subjective well-being of older people, as those who reported that the support they received was either insufficient or met their needs had lower subjective well-being than those who were not in need of care. Our results also showed that receiving formal care was negatively related with subjective well-being among older adults in Northern Europe and Central and Eastern Europe. In the context of population ageing and the growing need for care, social policies that support both sides of the caregiving relationship could enhance subjective quality of life.