bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of the Electrodes’ Shape and Graphite Quality on the Arc Stability During Hydrogen Plasma Smelting Reduction of Iron Ores
Authors: Ernst Daniel , Zarl Michael Andreas , Farkas Manuel Andreas , Schenk Johannes
Published: February 2023

Reducing greenhouse gases (GHG), especially CO2, is necessary to counteract climate change. The European steel industry currently corresponds to 5.7% of the total EU emissions and must therefore minimize their GHG fractions in the future. One of the most promising technologies to eliminate CO2 emissions while directly reducing iron ore to steel in a single step is the hydrogen plasma smelting reduction. The stability of the plasma arc, which is determined by the properties and geometry of the graphite electrode, has a substantial impact on the process’ economic feasibility. To study the arc stability concerning the graphite quality, tip geometry, and electrode gap, a series of experiments is conducted. The results are evaluated to create stability maps and fields to identify stable process parameters. The geometry of the graphite cathode shows the primary influence on arc stability. Tips with a flat end (standard version) offering the most unstable and a machined step on the graphite cathode providing the most stable conditions. However, an additional coating to prevent side arcing leads to the deterioration of the arc. The two graphite grades tested, with different maximum grain sizes and price classes, show no great relevance to the stability of the arc.
Effects of Nb and Y on the Solidification Microstructure and Mechanical Properties of S321 Austenitic Stainless Steel
Authors: Cai Weihao , Wang Zhigang , Huang Chengcong , Qi Liang , Liu Xuwei , Hu Xiaoqiang
Published: February 2023

δ‐Ferrite plays a controversial role in austenitic stainless steel and controlling its morphology and distribution is essential for the optimization of the properties of stainless steel. Herein, the solidification microstructure of S321 stainless steel with the addition of Nb and Y is studied by electron probe microanalysis, nanoindentation, and transmission electron microscopy. The results show that the addition of Nb promotes the precipitation of (Nb, Ti)(C, N) and coarsens the grain boundary carbides in S321 stainless steel, resulting in a decrease in the solute carbon content near the grain boundaries and a delay in the δ → γ phase transformation. The addition of Y inhibits the segregation of Ni along the original austenite grain boundaries and promotes the δ → γ phase transformation. Furthermore, the morphology of δ‐ferrite changes from lathy δ to skeletal δ and the grain boundary carbide network is broken. The higher density dislocation due to the phase transformation leads to an increase in the hardness of S321 steel containing Y.
Kinetics and Microstructure Transformations of Oxide Scale on Hot Rolled Steel Strip for Hot‐Dip Galvanizing during Reduction Annealing in 30% H2–N2 Atmosphere
Authors: Sun Bin , Gao Sheng-Lun , Tang Dong-Shan , Qian Xing-Qiang , He Yong-Quan
Published: February 2023

The understanding of oxide scale reduction mechanisms after microstructure transformation under different preheating conditions is incomplete. Herein, the reduction kinetics and microstructure transformations of hot rolled steel strip oxide scale during reduction (30% H2–N2) annealing are studied in detail using thermogravimetric and microstructure analyses, and mathematical modeling based on the gas–solid reaction. The results show that the rate‐determining steps of the reduction reaction are nucleation and growth of new phase between 500 and 600 °C, and gas–solid interface reactions between 700 and 800 °C. Microstructure transformation of the oxide scale occurs during the preheating process: at 500 °C, the eutectoid iron preferentially dissolves, and short‐range diffusion of Fe ions into adjacent Fe3O4 increases their content in the metal oxide; at 600 °C, nucleation and growth of Fe1 − yO occur, and some Fe3O4 precipitates and white α‐Fe are found in the Fe1 − yO layer, whereas the majority of the Fe3O4/iron eutectoid structure is retained; between 700 and 800 °C, the oxide scale forms outer and inner layers of Fe3O4 and Fe1 − yO, respectively. After preheating and reduction, the reduced products are porous iron over 500–600 °C, while porous and dense iron occur at 700 °C; dense iron forms as whiskers or granules between 700 and 800 °C. The surface quality of hot rolled steel strip after reduction annealing is subsequently improved as surface cracks are infilled by the newly formed dense iron.
Nonparametric doubly robust estimation of causal effect on networks in observational studies
Authors: Liu Jie , Ye Fangjuan , Yang Yang
Published: February 2023

Interconnection of nodes takes great challenge to the estimation of causal effect in the network. In this study, we develop a nonparametric doubly robust (NDR) estimator to identify the causal effect in the presence of general interference on network observational data. The estimator combines the strengths of doubly robust mapping and nonparametric regression. Thus, it is consistent when either the treatment or the outcome model is properly specified and is free of parametric assumptions. The asymptotic properties of the proposed estimator are also proved. We demonstrate the robustness and effectiveness of NDR by simulation studies and apply this method to investigate the impact of installation of SnCR on ambient ozone concentration of 473 power plants in America.
Interaction of Pulsed Electric Modified Elephant Foot Yam (Amorphophallus paeoniifolius) Starch and Polyvinyl Alcohol to Enhance the Mechanical and Barrier Properties of Film
Authors: Singh Shubham , Sharanagat Vijay Singh , Desai Shivani , Kumar Kshitiz , Upadhyay Srishti , Chakraborty Gourav
Published: February 2023

Elephant foot yam starch (EFYS) is modified by the pulsed electric field (PEF, 4–16 kV cm−1) and used for the development of the biodegradable film. The increase in PEF intensity increases the oil (1.66–2.22 g g−1) and water absorption capacity (1.79–2.08 g g−1) and reduces the gelatinization temperature (Tg) and enthalpy (ΔΗ). Storage modulus (G') is found to be higher than loss modulus (G"), indicating strong gel characteristics of EFYS. Electrical intensity affects the degree of crystallinity and disrupts the granule's surface. Film prepared with PEF‐modified EFYS and different concentrations of polyvinyl alcohol (PVA, 25%, 50%, and 90%) shows that the increase in the concentration of PVA results in increased thickness, tensile strength, % elongation, water vapor permeability, water vapor transmission rate, seal strength, and solubility. PEF modification increases the film's mechanical and moisture barrier properties. The study proves that PEF changes the physico‐functional and structural characteristics of EFYS, making it suitable to be used in the biodegradable film.
New insight into the prediction of strength properties of cementitious mortar containing nano‐ and micro‐silica based on porosity using hybrid artificial intelligence techniques
Authors: Kazemi Ramin , Eskandari‐Naddaf Hamid , Korouzhdeh Tahereh
Published: February 2023

Nowadays, the accurate prediction of strength properties of cementitious materials containing nano‐ and micro‐silica (NS–MS) remains an open question because of the highly nonlinear function of its constituents on the porosity. In the present study, a combined framework is developed by integrating ant colony optimization (ACO), particle swarm optimization (PSO), and biogeography‐based optimization (BBO) with the artificial neural network (ANN) to predict compressive and flexural strengths of cement mortar in two different forms of ignoring (ANNII) and considering (ANNIII) the porosity as an input parameter. This procedure is accomplished considering the porosity effect on the strengths and implementing an experimental program containing 32 mixes (960 specimens) with different NS–MS contents at various ages. Macro‐ and micro‐structural analyses showed that NS–MS caused more decreased pore structure, and thus this situation increases strength properties compared to their separate use. Also, MBBO‐MOANNIII results indicated an improvement in convergence speed and model accuracy compared to other models. This improvement is because of considering the porosity.
Design‐oriented nonlinear‐elastic buckling analysis of reinforced concrete wall structures using convex optimization
Authors: Vestergaard Daniel , Poulsen Peter Noe , Hoang Linh Cao , Larsen Kasper Paaske , Feddersen Bent
Published: February 2023

The structural response of slender reinforced concrete (RC) structures may be highly nonlinear due to cracking, reinforcement yielding, and geometrically nonlinear effects. While advanced models can simulate the detailed response of such structures, they are generally ill‐suited for limit state verification in practical design scenarios due to a high computational and modeling effort. A design‐oriented method for evaluating the geometrically linear response of cracked RC wall structures was recently presented and demonstrated to allow the analysis of large‐scale models with more than 2400 finite shell elements within minutes on a standard personal computer. This paper proposes a design‐oriented numerical method for efficient instability analysis of slender RC wall structures, also enabling the inclusion of thermal effects. Based on a two‐step linearized buckling analysis, the method first determines the geometrically linear structural response by solving the complementary energy minimization problem, including, if relevant, thermal strains and reduced material stiffness. This solution is used to derive the sectional stiffness upon which a linearized buckling problem is formulated and subsequently solved as a linear eigenvalue problem. The model is validated using examples with exact solutions, and its applicability to large‐scale models is demonstrated through an example with a four‐story stairwell modeled using more than 3200 finite elements.
Comparative study of cigarette smoke, Klebsiella pneumoniae, and their combination on airway epithelial barrier function in mice
Authors: Li Kangchen , Mei Xiaofeng , Xu Kexin , Jia Lidan , Zhao Peng , Tian Yange , Li Jiansheng
Published: February 2023

Background

The airway epithelium acts as a physical barrier to protect pulmonary airways against pathogenic microorganisms and toxic substances, such as cigarette smoke (CS), bacteria, and viruses. The disruption of the structural integrity and dysfunction of the airway epithelium is related to the occurrence and progression of chronic obstructive pulmonary disease.

Purpose

The aim of this study is to compare the effects of CS, Klebsiella pneumoniae (KP), and their combination on airway epithelial barrier function.

Methods

The mice were exposed to CS, KP, and their combination from 1 to 8 weeks. After the cessation of CS and KP at Week 8, we observed the recovery of epithelial barrier function in mice for an additional 16 weeks. To compare the epithelial barrier function among different groups over time, the mice were sacrificed at Weeks 4, 8, 16, and 24 and then the lungs were harvested to detect the pulmonary pathology, inflammatory cytokines, and tight junction proteins. To determine the underlying mechanisms, the BEAS‐2B cells were treated with an epidermal growth factor receptor (EGFR) inhibitor (AG1478).

Results

The results of this study suggested that the decreased lung function, increased bronchial wall thickness (BWT), elevated inflammatory factors, and reduced tight junction protein levels were observed at Week 8 in CS‐induced mice and these changes persisted until Week 16. In the KP group, increased BWT and elevated inflammatory factors were observed only at Week 8, whereas in the CS + KP group, decreased lung function, lung tissue injury, inflammatory cell infiltration, and epithelial barrier impairment were observed at Week 4 and persisted until Week 24. To further determine the mechanisms of CS, bacteria, and their combination on epithelial barrier injury, we investigated the changes of EGFR and its downstream protein in the lung tissues of mice and BEAS‐2B cells. Our research indicated that CS, KP, or their combination could activate EGFR, which can phosphorylate and activate ERK1/2, and this effect was more pronounced in the CS + KP group. Furthermore, the EGFR inhibitor AG1478 suppressed the phosphorylation of ERK1/2 and subsequently upregulated the expression of ZO‐1 and occludin. In general, these results indicated that the combination of CS and KP caused more severe and enduring damage to epithelial barrier function than CS or KP alone, which might be associated with EGFR/ERK1/2 signaling.

Conclusion

Epithelial barrier injury occurred earlier, was more severe, and had a longer duration when induced by the combination of CS and KP compared with the exposure to CS or KP alone, which might be associated with EGFR/ERK signaling.
Altered gene expression in excitatory neurons is associated with Alzheimer's disease and its higher incidence in women
Authors: Garcia A. Xavier , Xu Jielin , Cheng Feixiong , Ruppin Eytan , Schäffer Alejandro A.
Published: February 2023

Introduction

Alzheimer's disease (AD) is a neurodegenerative disorder involving interactions between different cell types in the brain. Previous single‐cell and bulk expression Alzheimer's studies have reported conflicting findings about the key cell types and cellular pathways whose expression is primarily altered in this disease. We re‐analyzed these data in a uniform, coherent manner aiming to resolve and extend past findings. Our analysis sheds light on the observation that females have higher AD incidence than males.

Methods

We re‐analyzed three single‐cell transcriptomics datasets. We used the software Model‐based Analysis of Single‐cell Transcriptomics (MAST) to seek differentially expressed genes comparing AD cases to matched controls for both sexes together and each sex separately. We used the GOrilla software to search for enriched pathways among the differentially expressed genes. Motivated by the male/female difference in incidence, we studied genes on the X‐chromosome, focusing on genes in the pseudoautosomal region (PAR) and on genes that are heterogeneous across individuals or tissues for X‐inactivation. We validated findings by analyzing bulk AD datasets from the cortex in the Gene Expression Omnibus.

Results

Our results resolve a contradiction in the literature, showing that by comparing AD patients to unaffected controls, excitatory neurons have more differentially expressed genes than do other cell types. Synaptic transmission and related pathways are altered in a sex‐specific analysis of excitatory neurons. PAR genes and X‐chromosome heterogeneous genes, including, for example, BEX1 and ELK1, may contribute to the difference in sex incidence of Alzheimer's disease. GRIN1, stood out as an overexpressed autosomal gene in cases versus controls in all three single‐cell datasets and as a functional candidate gene contributing to pathways upregulated in cases.

Discussion

Taken together, these results point to a potential linkage between two longstanding questions concerning AD pathogenesis, involving which cell type is the most important and why females have a higher incidence than males.

Highlights

By reanalyzing three, published, single‐cell RNAseq datasets, we resolved a contradiction in the literature and showed that when comparing AD patients to unaffected controls, excitatory neurons have more differentially expressed genes than do other cell types.

Further analysis of the published single‐cell datasets showed that synaptic transmission and related pathways are altered in a sex‐specific analysis of excitatory neurons.

Combining analysis of single‐cell datasets and publicly available bulk transcriptomics datasets revealed that X‐chromosome genes, such as BEX1, ELK1, and USP11, whose X‐inactivation status is heterogeneous may contribute to the higher incidence in females of Alzheimer's disease.
Knowledge to Support Early Educators and Elementary School Teachers' Engagement in Family Literacy and Family Literacy Programs
Authors: Lynch Jacqueline , Prins Esther
Published: February 2023

Family literacy programs can be effective for supporting the literacy learning of both parents and children. Educators and community members can be constructive in establishing family literacy programs in their school and in the community. Having knowledge of successful family literacy programs is important for both initiating and continuing with family literacy engagement. In this article, we describe aspects of successful family literacy programs, including attention to the diversity of families. We begin with an overview of the changing definitions of literacy and common structures of family literacy programs and complete this review with areas for further research in family literacy.
Rock fragments influence the water retention and hydraulic conductivity of soils
Authors: Naseri Mahyar , Joshi Deep C. , Iden Sascha C. , Durner Wolfgang
Published: February 2023

Rock fragments (RFs) influence soil hydraulic properties (SHPs), and knowledge about the SHPs of stony soils is important in vadose zone hydrology. However, experimental evidence on effective SHPs of stony soils is still scarce and mostly restricted to water‐saturated conditions and low volumetric contents of RFs. We examined the influence of RFs on SHPs through a series of measurements. Stony soils were prepared by packing 250‐cm3 cylinders with soils of two textures (sandy loam and silt loam) and with different volumes of RFs (up to 50% v/v) with a diameter of 8–16 mm. Samples were prepared in a way that the background soils (diameter smaller than 2 mm) had identical bulk density. The simplified evaporation method was used to determine the effective SHPs of stony soils. We used the obtained SHP data to evaluate the performance of models, which predict the effective SHPs of stony soils from SHPs of the background soil. The results highlight the systematic dependency of SHPs on volumetric content of RFs. The difference between modeled and measured SHPs was substantial for cases in which the soil contained a high amount of RFs. Accounting for the moisture content of RFs improved the prediction of the effective water retention curve of stony soils compared with a simple scaling that used only the content of RFs. Among the evaluated models for the effective hydraulic conductivity, the model based on the general effective medium theory showed the best performance, particularly for low RF contents.
Upscaling soil moisture from point scale to field scale: Toward a general model
Authors: Brown William G. , Cosh Michael H. , Dong Jingnuo , Ochsner Tyson E.
Published: February 2023

Field‐scale soil moisture measurements are valuable but rarely available because the resolution of most satellite soil moisture products is too coarse, while most in situ sensors provide only point‐scale data. Previous upscaling approaches for such data are mostly site‐specific, and none are suitable to upscale data from the thousands of stations in existing monitoring networks. To help fill this gap, this research aims to develop a more broadly applicable upscaling approach using data from the Marena, Oklahoma, In Situ Sensor Testbed and a cosmic‐ray neutron rover. Rover survey data were used to measure average soil moisture for the ∼64‐ha field on 12 dates in 2019–2020. Statistical modeling was used to identify the soil, terrain, and vegetation properties influencing the relationships between the field‐scale rover data and point‐scale in situ data from six monitoring sites. Site‐specific linear upscaling models estimated the field average soil moisture with root mean squared error (RMSE) values ranging from 0.007 to 0.017 cm3 cm−3, but such models are not transferrable between sites. To create a more general model, Least Absolute Shrinkage and Selection Operator regression was used with a leave‐one‐out cross‐validation approach to identify the key predictors for upscaling. The resulting parsimonious model required only the point‐scale observations and sand content data and achieved RMSE values ranging from 0.006 to 0.031 cm3 cm−3 for the six monitoring sites. The texture‐based model demonstrated reasonable accuracy and is a promising step toward a general model that could be broadly applied for upscaling point‐scale in situ monitoring stations.
In vivo models to study neurogenesis and associated neurodevelopmental disorders—Microcephaly and autism spectrum disorder
Authors: Prasad Tuhina , Iyer Sharada , Chatterjee Sayoni , Kumar Megha
Published: February 2023

The genesis and functioning of the central nervous system are one of the most intricate and intriguing aspects of embryogenesis. The big lacuna in the field of human CNS development is the lack of accessibility of the human brain for direct observation during embryonic and fetal development. Thus, it is imperative to establish alternative animal models to gain deep mechanistic insights into neurodevelopment, establishment of neural circuitry, and its function. Neurodevelopmental events such as neural specification, differentiation, and generation of neuronal and non‐neuronal cell types have been comprehensively studied using a variety of animal models and in vitro model systems derived from human cells. The experimentations on animal models have revealed novel, mechanistic insights into neurogenesis, formation of neural networks, and function. The models, thus serve as indispensable tools to understand the molecular basis of neurodevelopmental disorders (NDDs) arising from aberrations during embryonic development. Here, we review the spectrum of in vivo models such as fruitfly, zebrafish, frog, mice, and nonhuman primates to study neurogenesis and NDDs like microcephaly and Autism Spectrum Disorder. We also discuss nonconventional models such as ascidians and the recent technological advances in the field to study neurogenesis, disease mechanisms, and pathophysiology of human NDDs.

This article is categorized under:

Cancer > Stem Cells and Development

Congenital Diseases > Stem Cells and Development

Neurological Diseases > Stem Cells and Development

Congenital Diseases > Genetics/Genomics/Epigenetics
Insights from yeast: Transcriptional reprogramming following metformin treatment is similar to that of deferiprone in a yeast Friedreich's ataxia model
Authors: Börklü Esra
Published: February 2023

In the absence of YFH1, the yeast ortholog of the human FXN gene, budding yeast Saccharomyces cerevisiae experience similar problems to those of cells with Friedreich's ataxia (FRDA). The comparable phenotypic traits consist of impaired respiration, problems in iron homeostasis, decreased oxidative stress tolerance, and diminished iron–sulfur cluster synthesis, rendering yeast of potential use in FRDA modeling and drug trials. Deferiprone, an iron chelator, is one of the long‐term studied potential drugs for FRDA, whereas metformin is a biguanide prescribed to treat type 2 diabetes. In the present study, the effects of deferiprone and metformin treatment on the yeast FRDA model are explored via RNA‐sequencing analyses. The comparative inquiry of transcriptome data reveals new promising roles for metformin in FRDA treatment since deferiprone and metformin treatments produce overlapping transcriptional and phenotypic responses in YFH1Δ cells. The results revealed that both deferiprone and metformin treatment does not rescue aerobic respiration in YFH1Δ cells, but they alleviate the FRDA phenotype probably by triggering the retrograde mitochondria‐to‐nucleus signaling.
Teaching Tragedy: Toward a Pedagogy of Accountability—The Every Campus A Refuge Model
Authors: Abdo Diya
Published: February 2023

In 2015—at the height of the Syrian refugee crisis—I was struggling with how to leverage my position as a tenured professor of English at Guilford College to respond in any meaningful, material way to this global calamity. A small Quaker liberal arts four-year institution in Greensboro, North Carolina, Guilford was the perfect place—in its ethos and history—to found an initiative like Every Campus A Refuge (ECAR), which advocates for housing refugees on campus grounds and supporting them in their resettlement.
The Power of Participatory and Immersive Filmmaking
Authors: Decherney Peter
Published: February 2023

FilmAid Kenya (FAK) runs film schools in refugee camps, and each year FAK trains dozens of young filmmakers in the Kakuma and Dadaab camps. Some FAK graduates go on to work as wedding photographers and freelance video journalists—jobs that have surprising demand in the camps. FAK’s most lasting contribution, however, is empowering young people to tell their personal stories. Many of the beautiful, often surprising, films made by FAK students have gone on to win film festival awards and contribute to the global conversation about refugees. When the films do not find audiences outside the camps, there is a cathartic power in the act of communicating. FAK has also built a creative community within the refugee camps. Students and graduates spend time at the FAK compound on their days off, even when the power supply is routinely suspended, disabling the cameras and editing stations.
Finding Place: Strengthening Pedagogical Practices on Forced Migration Through Interpersonal Understanding in Higher Education
Authors: Khan Aena , Northern Faith , Rao Sofia , Weil Adam , Hantzopoulos Maria
Published: February 2023

As conversations about forced migration shape curriculum, new literature details the problems faced by forcibly displaced refugees. There are fewer resources, however, about how to engage with and highlight migrant voices in our actual classrooms. This paper offers a breakdown of a course offered at Vassar College that sought to devise a novel, grassroots approach to studies of forced migration and education. Titled “Finding Place: Refugee Youth Schooling Experiences in Athens, Greece,” the goals of the course included understanding the socio-economic conditions leading to refugee displacement to Greece, partnering with a refugee-led community organization in Athens for educational programming, and assisting with fieldwork research on refugee education. This chapter discusses how the course integrated restorative justice pedagogy, using one workshop as an example. The chapter also details the course’s pivots and pitfalls, particularly as a result of pandemic-related restrictions upon travel. The authors conclude with recommendations for future initiatives based on experiences with developing instructional material.
Climate Change, Human Displacement, and STEM Education: Toward a More Transdisciplinary and Inclusive Culture of Science
Authors: Schwarz Jodi
Published: February 2023

In this chapter I discuss opportunities for undergraduate education to support STEM scholars and students in centering social justice so that science can more meaningfully address global challenges such as the forced migration of people living in regions on the front lines of climate change. Traditional academic training structures in the STEM fields pose challenges for broadening STEM, so I suggest ideas for academic experiences that incorporate human dimensions into science education. As an example, the Grand Challenges program at Vassar College is an initiative that supports students and faculty in developing perspectives and skills that transcend traditional disciplines and in building community to meet global grand challenges, such as climate change. By creating pathways for students, faculty, and staff to form communities of practice, the Grand Challenges program examines the culture and practice of STEM fields and seeks to cultivate an Inclusive Excellence framework in which science can excel only when its practitioners bring diverse perspectives, lived experiences, knowledges, and skills to solving global challenges.
Learning at the Borders: How an Experiential Learning Course in Bern, Switzerland, Transformed Undergraduate Learning About Memory, Mental Health, and Displacement
Authors: Brown Adam D. , Elias Alexa L.
Published: February 2023

Migration journeys, especially in the context of forced migration, are often associated with exposure to high levels of stress, adversity, and unstable conditions. Displacement from one’s home often significantly affects one’s sense of self-identity and life story, and is accompanied by a rupture from many of those things—materials, spaces, relationships—that provide perspective, insights, and a sense of self-continuity. In addition to objects and spaces, self-identities are also constructed from cognitive processes, which give rise to internal representations and beliefs of where we come from, who we are today, and where we might be going in the future. These representations emerge in part from memories accumulated throughout one’s life.
Refugees and Forced Migration: An Engaged Humanities Course in French and Francophone Studies
Authors: Krause Virginia
Published: February 2023

This chapter recounts the development of a community-engaged course on refugees and displacement with a broad Humanities orientation offered in the Department of French and Francophone Studies at Brown University. It relates the overall structure of the course as well as the forging of a partnership with Women’s Refugee Care, an NGO supporting refugees from Central Africa living in Providence. Finally, the chapter explores the connections between the literary and theoretical texts on the course syllabus and the projects that students undertook in collaboration with the Women’s Refugee Care community.
Sensitivity of the FACET experiment to Heavy Neutral Leptons and Dark Scalars
Authors: Ovchynnikov Maksym , Kryshtal Viktor , Bondarenko Kyrylo
Published: February 2023

Abstract

We analyze the potential of the recently proposed experiment FACET (Forward-Aperture CMS ExTension) to search for new physics. As an example, we consider the models of Higgs-like scalars with cubic and quartic interactions and Heavy Neutral Leptons. We compare the sensitivity of FACET with that of other proposed “intensity frontier” experiments, including FASER2, SHiP, etc. and demonstrate that FACET could probe an interesting parameter space between the current constraints and the potential reach of the above mentioned proposals.
Activation of aryl hydrocarbon receptor (AhR) in Alzheimer’s disease: role of tryptophan metabolites generated by gut host-microbiota
Authors: Salminen Antero
Published: February 2023

Gut microbiota in interaction with intestinal host tissues influences many brain functions and microbial dysbiosis has been linked with brain disorders, such as neuropsychiatric conditions and Alzheimer’s disease (AD). l-tryptophan metabolites and short-chained fatty acids (SCFA) are major messengers in the microbiota-brain axis. Aryl hydrocarbon receptors (AhR) are main targets of tryptophan metabolites in brain microvessels which possess an enriched expression of AhR protein. The Ah receptor is an evolutionarily conserved, ligand-activated transcription factor which is not only a sensor of xenobiotic toxins but also a pleiotropic regulator of both developmental processes and age-related tissue degeneration. Major microbiota-produced tryptophan metabolites involve indole derivatives, e.g., indole 3-pyruvic acid, indole 3-acetaldehyde, and indoxyl sulfate, whereas indoleamine and tryptophan 2,3-dioxygenases (IDO/TDO) of intestine host cells activate the kynurenine (KYN) pathway generating KYN metabolites, many of which are activators of AhR signaling. Chronic kidney disease (CKD) increases the serum level of indoxyl sulfate which promotes AD pathogenesis, e.g., it disrupts integrity of blood–brain barrier (BBB) and impairs cognitive functions. Activation of AhR signaling disturbs vascular homeostasis in brain; (i) it controls blood flow via the renin-angiotensin system, (ii) it inactivates endothelial nitric oxide synthase (eNOS), thus impairing NO production and vasodilatation, and (iii) it induces oxidative stress, stimulates inflammation, promotes cellular senescence, and enhances calcification of vascular walls. All these alterations are evident in cerebral amyloid angiopathy (CAA) in AD pathology. Moreover, AhR signaling can disturb circadian regulation and probably affect glymphatic flow. It seems plausible that dysbiosis of gut microbiota impairs the integrity of BBB via the activation of AhR signaling and thus aggravates AD pathology.

Key messages

Dysbiosis of gut microbiota is associated with dementia and Alzheimer’s disease.

Tryptophan metabolites are major messengers from the gut host-microbiota to brain.

Tryptophan metabolites activate aryl hydrocarbon receptor (AhR) signaling in brain.

The expression of AhR protein is enriched in brain microvessels and blood-brain barrier.

Tryptophan metabolites disturb brain vascular integrity via AhR signaling.

Dysbiosis of gut microbiota promotes inflammation and AD pathology via AhR signaling.
Area disadvantage and mental health over the life course: a 69-year prospective birth cohort study
Authors: Bakolis Ioannis , Murray Emily T. , Hardy Rebecca , Hatch Stephani L. , Richards Marcus
Published: February 2023

Purpose

Existing evidence on the mental health consequences of disadvantaged areas uses cross-sectional or longitudinal studies with short observation periods. The objective of this research was to investigate this association over a 69-year period.

Methods

Data were obtained from the MRC National Survey of Health and Development (NSHD; the British 1946 birth cohort), which consisted of 2125 participants at 69 years. We assessed longitudinal associations between area disadvantage and mental health symptoms at adolescence and adulthood with use of multilevel modelling framework.

Results

After adjustment for father’s social class, for each one percentage increase in area disadvantage at age 4, there was a 0.02 (95% CI 0.001, 0.04) mean increase in the total score of the neuroticism scale at age 13–15. After adjustment for father’s social class, adult socio-economic position, cognitive ability and educational attainment, a one percentage increase in change score of area disadvantage between age 4 and 26 was associated with a mean increase in the total Psychiatric Symptom Frequency score (MD 0.06; 95% CI 0.007, 0.11). Similar associations were observed with change scores between ages 4, 53, 60 and total General Health Questionnaire-28 score at age 53 (MD 0.05; 95% CI 0.01, 0.11) and 60–64 (MD 0.06; 95% CI 0.009, 0.11).

Conclusions

Cohort members who experienced increasing area disadvantage from childhood were at increased risk of poor mental health over the life course. Population-wide interventions aiming at improving social and physical aspects of the early neighbourhood environment could reduce the socio-economic burden of poor mental health.
A blended face-to-face and smartphone intervention to improve suicide prevention literacy and help-seeking intentions among construction workers: a randomised controlled trial
Authors: King Tania L. , Fleitas Alfonzo Ludmila , Batterham Philip , Mackinnon Andrew , Lockwood Chris , Harvey Samuel , Kelly Brian , Lingard Helen , Cox Laura , LaMontagne Tony D.
Published: February 2023

Purpose

In Australia and elsewhere, suicide rates among construction workers remain high. Construction workplaces are thus an important setting for targeted suicide prevention programs. This study aimed to compare suicide prevention literacy and help-seeking intentions among participants receiving face-to-face suicide prevention training, with those receiving face-to-face training augmented by a smartphone application.

Methods

A two-arm randomised controlled trial of a smartphone suicide prevention intervention was conducted among construction workers in four Australian states (trial registration number: ACTRN12619000625178). All participants received face-to-face training and were randomised to the control condition (face-to-face only, n = 575), or MATESmobile condition (face-to-face + smartphone application,n = 509). Surveys administered at baseline and 3-month follow-up measured suicide prevention literacy and help-seeking intentions for personal/emotional problems and suicidal thoughts. A mixed-model repeated measures (MMRM) analysis included all 1084 randomised participants.

Results

Outcomes did not differ significantly for suicide prevention literacy, nor help-seeking intentions from formal sources, informal sources outside the workplace, or no one (did not intend to seek help from anyone). However, relative to those in the control condition, those in the MATESmobile group showed greater increase in help-seeking intentions for emotional problems from a MATES worker/Connector (mean difference 0.54, 95% CI 0.22–0.87) and help-seeking intentions for suicidal thoughts from a workmate (mean difference 0.47, 95% CI 0.10–0.83) or MATES worker/Connector (mean difference 0.47, 95% CI 0.09–0.85).

Conclusion

Results indicate that the MATESmobile application, together with face-to-face training, is beneficial in enhancing help-seeking intentions from MATES workers/Connectors and workmates to a greater extent than face-to-face training only. While this research provides some evidence that smartphone applications may support suicide prevention training, further research is needed.
Lights and GDP relationship: What does the computer tell us?
Authors: Phan Diep Hoang
Published: February 2023

The relationship between nighttime lights and GDP varies from country to country. However, which factors drive variations in the lights–GDP relationship across countries remains unclear. This paper examines the significance of approximately 600 potential drivers of uncertainty in the relationship between night lights and GDP worldwide. I employ three novel modern statistical techniques to select variables within a high-dimensional context: LASSO, minimax concave penalty, and spike-and-slab regression. Institutional quality emerges as the most important factor in explaining the difference between luminosity data and GDP across countries.
Metastability of the Potts Ferromagnet on Random Regular Graphs
Authors: Coja-Oghlan Amin , Galanis Andreas , Goldberg Leslie Ann , Ravelomanana Jean Bernoulli , Štefankovič Daniel , Vigoda Eric
Published: February 2023

We study the performance of Markov chains for theq-state ferromagnetic Potts model on random regular graphs. While the cases of the grid and the complete graph are by now well-understood, the case of random regular graphs has resisted a detailed analysis and, in fact, even analysing the properties of the Potts distribution has remained elusive. It is conjectured that the performance of Markov chains is dictated by metastability phenomena, i.e., the presence of “phases” (clusters) in the sample space where Markov chains with local update rules, such as the Glauber dynamics, are bound to take exponential time to escape, and therefore cause slow mixing. The phases that are believed to drive these metastability phenomena in the case of the Potts model emerge as local, rather than global, maxima of the so-called Bethe functional, and previous approaches of analysing these phases based on optimisation arguments fall short of the task. Our first contribution is to detail the emergence of the two relevant phases for theq-state Potts model on thed-regular random graph for all integers$$q,d\ge 3$$q,d≥3, and establish that for an interval of temperatures, delineated by the uniqueness and a broadcasting threshold on thed-regular tree, the two phases coexist (as possible metastable states). The proofs are based on a conceptual connection between spatial properties and the structure of the Potts distribution on the random regular graph, rather than complicated moment calculations. This significantly refines earlier results by Helmuth, Jenssen, and Perkins who had established phase coexistence for a small interval around the so-called ordered-disordered threshold (via different arguments) that applied for largeqand$$d\ge 5$$d≥5. Based on our new structural understanding of the model, our second contribution is to obtain metastability results for two classical Markov chains for the Potts model. We first complement recent fast mixing results for Glauber dynamics by Blanca and Gheissari below the uniqueness threshold, by showing an exponential lower bound on the mixing time above the uniqueness threshold. Then, we obtain tight results even for the non-local and more elaborate Swendsen–Wang chain, where we establish slow mixing/metastability for the whole interval of temperatures where the chain is conjectured to mix slowly on the random regular graph. The key is to bound the conductance of the chains using a random graph “planting” argument combined with delicate bounds on random-graph percolation.
Lacertus syndrome: a ten year analysis of two hundred and seventy five minimally invasive surgical decompressions of median nerve entrapment at the elbow
Authors: Hagert Elisabet , Jedeskog Ulrika , Hagert Carl-Göran , Marín Fermín Theodorakys
Published: February 2023

Purpose

This study aims to assess the clinical presentation and surgical outcomes of lacertus syndrome (LS) and concomitant median nerve entrapments.

Methods

A retrospective study of prospectively collected data was conducted on patients undergoing lacertus release (LR) from June 2012 to June 2021. Available DASH (Disability of the Arm Shoulder Hand questionnaire) scores and post-operative Visual Analogue Scale (VAS) of pain, numbness, subjective satisfaction with surgical outcome, and intra-operative return of strength were analyzed.

Results

Two-hundred-seventy-five surgical cases were identified of which 205 cases (74.5%) underwent isolated LR, and 69 cases (25.1%) concomitant lacertus and carpal tunnel release. The three most common presenting symptoms in LS patients were loss of hand strength (95.6%), loss of hand endurance/fatigue (73.3%), and forearm pain (35.4%). Numbness in the median nerve territory of the hand was found in all patients with combined LS and carpal tunnel syndrome. Quick-DASH significantly improved (pre-operative 34.4 (range 2.3–84.1) to post-operative 12.4 (range 0–62.5), p < 0.0001) as did work and activity DASH (p < 0.0001). The postoperative VAS scores were pain VAS 1.9 and numbness VAS 1.8. Eighty-eight percent of patients reported good/excellent satisfaction with the surgical outcome. Intra-operative return of strength was verified in 99.2% of cases.

Conclusion

LS is a common median nerve compression syndrome typically presenting with loss of hand strength and hand endurance/fatigue. Minimally invasive LR immediately restores hand strength, significantly improves DASH scores, and yields positive outcomes regarding VAS pain, numbness, and subjective satisfaction with surgery in patients with proximal median nerve entrapment at a minimum six month follow-up.
Parsimony and the rank of a flattening matrix
Authors: Snyman Jandre , Fox Colin , Bryant David
Published: February 2023

The standard models of sequence evolution on a tree determine probabilities for every character or site pattern. A flattening is an arrangement of these probabilities into a matrix, with rows corresponding to all possible site patterns for one setAof taxa and columns corresponding to all site patterns for another setBof taxa. Flattenings have been used to prove difficult results relating to phylogenetic invariants and consistency and also form the basis of several methods of phylogenetic inference. We prove that the rank of the flattening equals$$r^{\nu _T(A|B)}$$rνT(A|B), whereris the number of states and$$\nu _T(A|B)$$νT(A|B)is the minimum size of a vertex cut separatingAfromB. WhenTis binary the rank of the flattening equals$$r^{\ell _T(A|B)}$$rℓT(A|B)where$$\ell _T(A|B)$$ℓT(A|B)equals the parsimony length of the binary character separatingAandB. We provide a direct proof that requires little more than undergraduate algebra, but note that the formula could also be derived from work by Casanellas and Fernández-Sánchez (2011) on phylogenetic invariants.
Centre-free kurtosis orderings for asymmetric distributions
Authors: Eberl Andreas , Klar Bernhard
Published: February 2023

The concept of kurtosis is used to describe and compare theoretical and empirical distributions in a multitude of applications. In this connection, it is commonly applied to asymmetric distributions. However, there is no rigorous mathematical foundation establishing what is meant by kurtosis of an asymmetric distribution and what is required to measure it properly. All corresponding proposals in the literature centre the comparison with respect to kurtosis around some measure of central location. Since this either disregards critical amounts of information or is too restrictive, we instead revisit a canonical approach that has barely received any attention in the literature. It reveals the non-transitivity of kurtosis orderings due to an intrinsic entanglement of kurtosis and skewness as the underlying problem. This is circumvented by restricting attention to sets of distributions with equal skewness, on which the proposed kurtosis ordering is shown to be transitive. Moreover, we introduce a functional that preserves this order for arbitrary asymmetric distributions. As application, we examine the families of Weibull and sinh-arcsinh distributions and show that the latter family exhibits a skewness-invariant kurtosis behaviour.
A systematic review of the association between parastomal hernia and sarcopenia
Authors: Schutte Grant , Patton Declan , Moore Zena , McNamara Deborah , O’Connor Tom , Nugent Linda , Avsar Pinar
Published: February 2023

Background

Sarcopenia is a multifactorial loss of muscle mass that can complicate surgical outcomes and increase morbidity and mortality. Parastomal hernias can occur after any surgery requiring stoma formation and is an area of concern as a complication as it can require a second surgery or emergency surgical intervention.

Aim

To assess the impact of sarcopenia on parastomal hernia formation in the postoperative period.

Method

A systematic search of publications using MEDLINE, CINAHL, and Cochrane databases was conducted in June 2022. Data were extracted, and a narrative synthesis was undertaken. The Crowe Critical Appraisal Tool (CCAT) assessed the quality of the included studies. The systematic review included original research studies, prospective and retrospective designs, and human studies written in English. Reviews, conference papers, opinion papers, and those including participants < 18 years old were excluded. No restrictions on the date of publication and study setting were applied.

Results

Nine studies met the inclusion criteria, and these were conducted between 2016 and 2021; 56% (n = 5) used a retrospective study design. The mean sample size was 242.5 participants (SD = ±358.6). No consistent or standardized way of defining sarcopenia or measuring muscle mass was seen between the studies reviewed. However, 45% (n = 4) of the studies reported a significant relationship between sarcopenia and wound healing complications, including an increased incidence of parastomal and incisional hernias. The average CCAT score was 27.56 (SD = ±4.39).

Conclusion

There is no definitive relationship between sarcopenia and hernia development; however, four studies found a significant relationship between sarcopenia and hernia formation. It must also be considered that different disease processes can cause sarcopenia either through the disease process itself, or the treatment and management. More research and consistent measurements are needed before comparable and consistent outcomes can be compiled.