bluuebunny/crossref_metadata_2025 huggingface dataset:
In vitro evaluation of the impact of intraoral scanner, scanning aids, and the scanned arch on the scan accuracy of edentulous arches
Authors: Jamjoom Faris Z. , Aldghim Adhwaa , Aldibasi Omar , Yilmaz Burak
Published: July 2024

Purpose

To assess the accuracy of complete maxillary and mandibular edentulous arch scans obtained using two different intraoral scanners (IOSs), with and without scanning aids, and to compare these results to those obtained using conventional impression methods.

Materials and Methods

Two IOSs were used (TRIOS 4 [TRI] and Emerald S [EMR]) to scan maxillary and mandibular typodonts. The typodonts were scanned without scanning aids [TRI_WSA and EMR_WSA groups] (n = 10). The typodonts were then scanned under four scanning aid conditions (n = 10): composite markers [TRI_MRK and EMR_MRK groups], scanning spray [TRI_SPR and EMR_SPR groups], pressure indicating paste [TRI_PIP and EMR_PIP groups], and liquid‐type scanning aid [TRI_LQD and EMR_LQD groups]. Conventional impressions of both arches were also made using irreversible hydrocolloids in stock trays [IHC] and using polyvinyl siloxane (PVS) impression material in custom trays (n = 10) which were digitized using a laboratory scanner. Using a metrology software program, all scans were compared to a reference scan in order to assess trueness and to each other to assess precision. Trueness and precision were expressed as the root mean square (RMS) of the absolute deviation values and the statistical analysis was modeled on a logarithmic scale using fixed‐effects models to meet model assumptions (α = 0.05).

Results

The main effect of arch (p = 0.004), scanner (p < 0.001), scanning aid (p = 0.041), and the interaction between scanner and scanning aid (p = 0.027) had a significant effect on mean RMS values of trueness. The arch (p = 0.015) and scanner (p < 0.001) had a significant effect on the mean RMS values of precision. The maxillary arch had better accuracy compared to the mandible. The TRIOS 4 scanner had better accuracy than both the Emerald S scanner and conventional impressions. The Emerald S had better precision than conventional impressions. The scanning spray and liquid‐type scanning aids produced the best trueness with the TRIOS 4 scanner, while the liquid‐type scanning aid and composite markers produced the best trueness for the Emerald S scanner.

Conclusion

The scanned arch and the type of scanner had a significant effect on the accuracy of digital scans of completely edentulous arches. The scanning aid had a significant effect on the trueness of digital scans of completely edentulous arches which varied depending on the scanner used.
Dental anxiety and oral health in American Indian and Alaska natives
Authors: Tiwari Tamanna , Wright Casey D. , Heaton Lisa J. , Santoro Morgan , Tranby Eric P.
Published: July 2024

Objective

American Indian and Alaska native (AI/AN) individuals report distrust of the healthcare system. This study explored associations between having either high levels of dental distrust or high levels of dental care‐related fear and anxiety (“dental anxiety”) and oral health outcomes in AI/AN adults.

Methods

The 2022 State of Oral Health Equity in America survey included the Modified Dental Anxiety Scale and asked to what extent respondents agreed with the statement, “At my last oral health visit, I trusted the oral health provider I saw”, and asked about self‐rated oral health and presence of a dental home.

Results

AI/AN individuals (N = 564) who reported low dental trust (n = 110) or with high dental anxiety (MDAS≥19; n = 113) reported significantly worse overall and oral health and were significantly less likely to have a dental home (p < 0.05 used for each analysis).

Conclusion

Dental distrust and dental anxiety can significantly impact oral health and dental utilization in AI/AN communities and are important intervention targets to improve AI/AN oral health.
Effects of oxidized LDL versus IL‐1ß/TNF‐ɑ/INFɣ on human gingival mesenchymal stem cells properties
Authors: Fawzy El‐Sayed Karim , Mahlandt Elena , Schlicht Kristina , Enthammer Kim , Tölle Johannes , Wagner Juliane , Hartmann Katharina , Ebeling Peter R. , Graetz Christian , Laudes Mathias , Dörfer Christof E. , Schulte Dominik M.
Published: July 2024

Aims

Oxidized low‐density lipoprotein (oxLDL) is an important player in the course of metabolic inflammatory diseases. oxLDL was identified in the gingival crevicular fluid, denoting possible associations between oxLDL‐induced inflammation and periodontal disease. The current investigation compared for the first‐time direct effects of oxLDL to a cytokine cocktail of IL‐1ß/TNF‐ɑ/INF‐γ on gingival mesenchymal stem cells' (G‐MSCs) attributes.

Methods

Human third passage G‐MSCs, isolated from connective tissue biopsies (n = 5) and characterized, were stimulated in three groups over 7 days: control group, cytokine group (IL‐1β[1 ng/mL], TNF‐α[10 ng/mL], IFN‐γ[100 ng/mL]), or oxLDL group (oxLDL [50 μg/mL]). Next Generation Sequencing and KEGG pathway enrichment analysis, stemness gene expression (NANOG/SOX2/OCT4A), cellular proliferation, colony‐formation, multilinear potential, and altered intracellular pathways were investigated via histochemistry, next‐generation sequencing, and RT‐qPCR.

Results

G‐MSCs exhibited all mesenchymal stem cells' characteristics. oxLDL group and cytokine group displayed no disparities in their stemness markers (p > .05). Next‐generation‐sequencing revealed altered expression of the TXNIP gene in response to oxLDL treatment compared with controls (p = .04). Following an initial boosting for up to 5 days by inflammatory stimuli, over 14 day, cellular counts [median count ×10−5 (Q25/Q75)] were utmost in control – [2.6607 (2.0804/4.5357)], followed by cytokine – [0.0433 (0.0026/1.4215)] and significantly lowered in the oxLDL group [0.0274 (0.0023/0.7290); p = .0047]. Osteogenic differentiation [median relative Ca2+ content(Q25/Q75)] was significantly lower in cytokine – [0.0066 (0.0052/0.0105)] compared to oxLDL – [0.0144 (0.0108/0.0216)] (p = .0133), with no differences notable for chondrogenic and adipogenic differentiation (p > .05).

Conclusions

Within the current investigation's limitations, in contrast to cytokine‐mediated inflammation, G‐MSCs appear to be minimally responsive to oxLDL‐mediated metabolic inflammation, with little negative effect on their differentiation attributes and significantly reduced cellular proliferation.
Nightmares in Swiss elite athletes: Associated factors
Authors: Schredl Michael , Vorster Albrecht , Schmid Michael J. , Erlacher Daniel
Published: July 2024

Nightmares, defined as extremely dysphoric dreams, can cause significant distress in everyday life if they occur frequently. Their aetiology is based on a disposition‐stress model. As elite athletes often experience high stress levels, the present study investigated factors that might be associated with nightmare frequency in a large cohort of 2297 Swiss elite athletes (1066 women, 1231 men) with a mean age of 22.05 ± 7.53 years. In total, about 6% of the athletes reported frequent nightmares (once a week or more often). We found that well‐established factors like female gender and general stress levels were related to nightmare frequency. To a smaller extent, the number of training hours, lost training days due to illness, and having early training sessions were also associated with nightmare frequency. Sport discipline was not related to nightmare frequency. An unexpected finding was the association between late alcohol intake 4 hr prior to bedtime and nightmare frequency. Our findings support the idea that stress related to practicing sports might affect nightmare frequency. Future research should study whether inventions designed for athletes suffering from frequent nightmares are beneficial for them and might even improve their athletic performance.
Correlation of rheology and oral tribology with sensory perception of commercial hazelnut and cocoa‐based spreads
Authors: Principato Laura , Carullo Daniele , Gruppi Alice , Lambri Milena , Bassani Andrea , Spigno Giorgia
Published: July 2024

This study examined the effects of spread formulation and the structural/lubricant properties of six different commercial hazelnut and cocoa spreads on sensory perception. Rheology, tribology, and quantitative descriptive analysis (QDA) was assessed by also evaluating the correlation coefficients between the quality descriptor and the rheological and textural parameters. The viscosity was evaluated at different temperatures to better simulate conditions before and after ingestion. Tribological analysis was executed at 37°C to mimic the human oral cavity. The effect of saliva presence and the number of runs on tribological behaviors was investigated. Moreover, textural, calorimetric, and particle size distribution measurements were performed to reinforce the correlation between structural/thermal parameters (e.g., firmness, stickiness, sugar melting point) and sensory aspects. “Visual viscosity,” defined as a sensory attribute evaluated prior to consumption, negatively correlated with apparent viscosity measured at 20°C and 10 s−1, whereas “body,” defined during oral processing and related to creaminess, positively correlated with apparent viscosity measured at 37°C and 50 s−1. These attributes were mainly influenced by particulate microstructure and solid volume fraction within the formulation. Textural stickiness positively correlated with sensory “adhesiveness” and was related to fat composition and milk powder addition, while “sweetness” was related to sucrose content and sugar melting enthalpy. Tribological data provided meaningful information related to particle‐derived attributes, as well as after‐coating perception (fattiness/oiliness), thus better predicting food evolution during oral consumption.
Incidence of myopia in Swedish schoolchildren: A longitudinal study
Authors: Demir Pelsin , Baskaran Karthikeyan , Ramos Pedro Lima , Naduvilath Thomas , Sankaridurg Padmaja , Macedo Antonio Filipe
Published: July 2024

Purpose

The prevalence of myopia in Scandinavia tends to be lower than in other parts of the world. This study aimed to investigate the incidence of myopia and its predictors in Swedish children to characterise this trend.

Methods

A 2‐year longitudinal study was conducted following a cohort of schoolchildren aged 8–16 years. Myopia was defined as a spherical equivalent refraction (SER) ≤ −0.50 D. The study enrolled 128 participants, 70 (55%) females with a mean age of 12.0 years (SD = 2.4).

Results

The cumulative incidence of myopia during the follow‐up period was 5.5%, and the incidence rate of myopia was 3.2 cases per 100 person‐years. Participants with myopia at baseline exhibited a faster increase in refractive error during the follow‐up period. Likewise, participants with two myopic parents exhibited a more marked change towards myopia, regardless of their initial refractive error.

Conclusion

In the current study, similar to prevalence, the incidence of myopia was low when compared with other parts of the world. These results lead us to formulate a new hypothesis that the normal emmetropisation process may be protected by low educational pressure practised in Sweden during early childhood. Further research is necessary to test this new hypothesis.
Cortical and subcortical brain networks predict prevailing heart rate
Authors: Sentis Amy Isabella , Rasero Javier , Gianaros Peter J. , Verstynen Timothy D.
Published: July 2024

Resting heart rate may confer risk for cardiovascular disease (CVD) and other adverse cardiovascular events. While the brainstem's autonomic control over heart rate is well established, less is known about the regulatory role of higher level cortical and subcortical brain regions, especially in humans. This study sought to characterize the brain networks that predict variation in prevailing heart rate in otherwise healthy adults. We used machine learning approaches designed for complex, high‐dimensional data sets, to predict variation in instantaneous heart period (the inter‐heartbeat‐interval) from whole‐brain hemodynamic signals measured by fMRI. Task‐based and resting‐state fMRI, as well as peripheral physiological recordings, were taken from two data sets that included extensive repeated measurements within individuals. Our models reliably predicted instantaneous heart period from whole‐brain fMRI data both within and across individuals, with prediction accuracies being highest when measured within‐participants. We found that a network of cortical and subcortical brain regions, many linked to visceral motor and visceral sensory processes, were reliable predictors of variation in heart period. This adds to evidence on brain–heart interactions and constitutes an incremental step toward developing clinically applicable biomarkers of brain contributions to CVD risk.
A quasi‐normative conflict: Resolving the tension between investment treaties and climate action
Authors: Zhu Ying
Published: July 2024

The conflict between investment treaties and climate action is escalating due to recent investment arbitration cases challenging States' fossil fuel phase‐out measures as violations of investment treaty obligations. As countries continue to implement climate mitigation and adaptation measures across various industries, this tension is expected to result in a rise in climate‐related investment arbitration claims. The current literature has primarily presented the tension between investment and climate treaties as a vertical conflict, with investment treaties having a chilling effect on States' climate regulation. The common defence for States' regulation has been based on their ‘right to regulate’. It remains unclear whether there exists a horizontal conflict between investment and climate treaties, primarily due to the flexible nature of climate treaty obligations. However, a sovereignty‐based justification fails to recognise the international obligation of climate action and is insufficient for reconciling the conflict. This article delves into the intricate nature of the conflict between States' climate measures and their investment treaty obligations and argues that the conflict exhibits a ‘quasi‐normative’ nature, given the combination of binding climate obligations, permissive implementation methods and normative expectations of ambition. The article suggests that investment treaties should include clearly defined conflict clauses that outline the scope of the conflict between investment and climate treaties and establish specific mechanisms for resolving such conflicts.
Up you get: Norwegian parents' reactions to children's negative emotions
Authors: Bjørk Rune F. , Havighurst Sophie S. , Fredriksen Eivor , Bølstad Evalill
Published: July 2024

Introduction

Developmental research suggests that children learn to regulate their emotions and behavior through a process of emotion socialization. The main body of literature is based on samples from the United States, and very little is known about the socialization of emotions in Nordic settings.

Objectives

The current study aimed to explore associations between mothers' and fathers' reactions to children's negative emotions and externalizing behavior problems in a Nordic cultural context, and to explore gender differences in these associations.

Methods

Parent‐report data on the Coping with Children's Negative Emotions Scale (CCNES) and the Eyberg Child Behavior Inventory 6 (ECBI) was collected in a large sample of Norwegian preschool‐aged children (mothers, n = 242; fathers, n = 183; N = 257; M = 54 months, SD = 4.54; 49% boys). Teacher‐report data was collected using the Strengths and Difficulties Questionnaire (SDQ) conduct scale (n = 117).

Results

Both parents' supportive and non‐supportive reactions were associated with child externalizing difficulties in expected directions as evidenced by path models, controlling for socioeconomic status and age. A pattern emerged in which non‐supportive reactions to a greater extent predicted an increase in externalizing problems in girls, and supportive reactions predicted lower levels of externalizing problems in boys.

Conclusion

Our findings supported the basic assumptions of emotion socialization theory in a Nordic cultural context in which parental supportive and non‐supportive responses are related to child externalizing difficulties. Nordic parents are important socialization agents for their children, but their behaviors had a differential effect on boys' and girls' externalizing behavior problems.
Validation of point process predictions with proper scoring rules
Authors: Heinrich‐Mertsching Claudio , Thorarinsdottir Thordis L. , Guttorp Peter , Schneider Max
Published: July 2024

We introduce a class of proper scoring rules for evaluating spatial point process forecasts based on summary statistics. These scoring rules rely on Monte Carlo approximations of expectations and can therefore easily be evaluated for any point process model that can be simulated. In this regard, they are more flexible than the commonly used logarithmic score and other existing proper scores for point process predictions. The scoring rules allow for evaluating the calibration of a model to specific aspects of a point process, such as its spatial distribution or tendency toward clustering. Using simulations, we analyze the sensitivity of our scoring rules to different aspects of the forecasts and compare it to the logarithmic score. Applications to earthquake occurrences in northern California, United States and the spatial distribution of Pacific silver firs in Findley Lake Reserve in Washington highlight the usefulness of our scores for scientific model selection.
Exploring the utility of the Enhanced Vegetation Index as rainfall and agricultural proxy in a Caribbean case study event
Authors: Buckland Sarah F.
Published: July 2024

Highly fragile small island states experience disproportionate climate impacts given their limited capacity to implement cost‐effective tools for detecting emerging signals of drying conditions and monitoring systems for sensitive sectors such as agriculture, especially for uncertain, ‘creeping’ events such as droughts. Despite the existence of open‐source Google Earth Engine datasets, untapped potential remains for their full deployment in disaster management infrastructure. Given this gap, this paper explores the utility of the Enhanced Vegetation Index (EVI) for detecting spatio‐temporal variations of Mid‐Summer Drought (MSD) impacts on vegetation in the small island of Jamaica, with emphasis on major historical drought events. Geospatial analyses of EVI datasets from the Terra Moderate‐Resolution Imaging Spectroradiometer (MODIS) between 2000−2015 archived by the United States Geological Survey (USGS), were computed, and validated by station‐based precipitation and production data for selected parishes for historical case study MSD events. Results revealed highly asymmetrical drought impacts, with Jamaica's agriculturally intense Southern coastline displaying the most stressed vegetation (EVI < 0.5). North‐Western and North‐Eastern regions had the healthiest vegetation during the MSD (EVI > 0.6). A ‘fair’ to ‘moderate’ concurrent correlation was found between EVI and precipitation (R > 0.6), with lower correlations vis‐a‐vis agricultural production (R = 0.2–0.4). The results provide evidence of EVI's utility as a drought monitoring tool in a small island context.
Syllabus as argument in an era of politicized pedagogy
Authors: Dougherty Michael L.
Published: July 2024

The traditional character of higher education in the US is under assault. The broad, intellectual focus on the liberal arts and its concomitant values of academic freedom and academic governance are giving way to an over‐managed vocational institution that prioritizes ambience over integrity and credentialism over citizenship. In this milieu, sociologists should use the classroom as an opportunity to model the explanatory power of the discipline by structuring our syllabi to make a point. I refer to this approach as syllabus‐as‐argument, which I contrast with the traditional organizational logic of syllabus‐as‐survey—configuring a syllabus to provide an overview of a given topic, theme or field. Where the chief criterion of success for the syllabus as survey is comprehensiveness, the syllabus as argument strives for convincingness. I draw from two courses to exemplify this approach. The first is a senior seminar in environmental sociology, which I have reworked into a course explaining the intractability of the climate crisis. The second is a general education course in community sociology that I remade to explain the links between growing inequality and deteriorating democracy in the US.
An exploratory study of structural and microvascular changes in the skin following electrical shaving using optical coherence topography
Authors: Chaturvedi Pakhi , Kroon Wilco , Zanelli Giulia , Worsley Peter R.
Published: July 2024

Background

Consumer products such as electrical shavers exert a combination of dynamic loading in the form of pressure and shear on the skin. This mechanical stimulus can lead to discomfort and skin tissue responses characterised as “Skin Sensitivity”. To minimise discomfort following shaving, there is a need to establish specific stimulus‐response relationships using advanced tools such as optical coherence tomography (OCT).

Objective

To explore the spatial and temporal changes in skin morphology and microvascular function following an electrical shaving stimulus.

Methods

Ten healthy male volunteers were recruited. The study included a 60‐s electrical shaving stimulus on the forearm, cheek and neck. Skin parameters were recorded at baseline, 20 min post stimulus and 24 h post stimulus. Structural and dynamic skin parameters were estimated using OCT, while transepidermal water loss (TEWL) was recorded to provide reference values for skin barrier function.

Results

At baseline, six of the eight parameters revealed statistically significant differences between the forearm and the facial sites, while only surface roughness (Rq) and reflectivity were statistically different (p < 0.05) between the cheek and neck. At 20 min post shaving, there was a significant increase in the TEWL values accompanied by increased blood perfusion, with varying magnitude of change dependent on the anatomical site. Recovery characteristics were observed 24 h post stimulus with most parameters returning to basal values, highlighting the transient influence of the stimulus.

Conclusions

OCT parameters revealed spatial and temporal differences in the skin tissue response to electrical shaving. This approach could inform shaver design and prevent skin sensitivity.
Exploring the influence of wealth on judicial decision making
Authors: Miller Banks , Curry Brett
Published: July 2024

Objective

Attention to levels of socioeconomic inequality has given rise to work investigating its potential to influence political actors and, thus, policy outcomes. These studies have focused on elected actors in legislative contexts. Ours fills this gap by assessing the consequences of a judge's wealth on decision making.

Methods

We obtain data on federal appellate judges’ wealth and explore its influence in cases involving economic issues. We estimate logit models controlling for other factors and include fixed effects for circuit, specific issue area, and year of the decision. The models consider both the main effects of wealth and its potential interaction with judicial ideology to influence decision making.

Results

We find no direct relationship between a judge's wealth and her decision making in economic cases. However, wealth interacts with ideology to exert a significant influence on decision making; here, greater wealth amplifies the ideological predilections of more conservative judges.

Conclusions

This is the first study to document a link between wealth and the choices judges make on the bench. It adds a new dimension to the ways economic inequality can influence political actors and raises new questions about the mechanisms by which such inequality is consequential for elite political behavior.
A case of cryptic diversity in the bat Hsunycteris thomasi (Lonchophyllinae, Chiroptera): New insights into unrecognized species
Authors: Benathar Thayse Cristine Melo , Trevelin Leonardo Carreira , Carneiro Jeferson Costa , Rodrigues Luis Reginaldo Ribeiro , Sampaio Iracilda , O'Brien Patricia Caroline , Ferguson‐Smith Malcolm Andrew , Yangg Fengtang , Nagamachi Cleusa Yoshiko , Pieczarka Julio César
Published: July 2024

Integrating different lines of evidence is currently recognized as the most robust approach to investigating taxonomic questions, particularly those concerning cryptic diversity. In recent years, different sources of evidence have pointed to new cryptic taxa for bats, with the genus Hsunycteris being an excellent study group because of its large karyotypic variability and high genetic divergence revealed by the latest taxonomic and systematic reviews. This study tests the cryptic diversity hypothesis for the Hsunycteris thomasi complex through an integrative approach using species delimitation, phylogenetic analysis, chromosome painting, and linear morphometry. Our results suggest the existence of three lineages for H. thomasi that are morphologically indistinguishable, confirming the two previously described lineages in the literature and adding a third. We argue that the paraphyly in H. thomasi, as reported by previous studies, should be treated as independent species since they have unique evolutionary histories. Finally, we demonstrate that chromosomal and molecular methods are indispensable for recognizing and confirming groups that include cryptic species or species with confusing and controversial taxonomy.
Feeling the Distance: Exploring Novice Student Designers' Perceptions of the Psychological Distance and Empathic Response Toward Variations of a Sustainable Design Problem
Authors: Prabhu Rohan , Herzog Jenna , Fodale Rebekah , Alsager Alzayed Mohammad , Starkey Elizabeth M.
Published: July 2024

Prior research suggests novice designers find it challenging to integrate social context into the engineering design process. This challenge could be particularly pronounced in sustainable design tasks because the effects of climate change are perceived to be psychologically distant, and this distance inhibits active engagement in sustainable behavior. However, most of this work assesses psychological distance as an aggregate of its various subcomponents (e.g., temporal, social, spatial, and hypothetical). Limited research has explored how these individual components vary based on the socio-spatial context of the design problem. Additionally, empathy development could be an effective mechanism to bridge psychological distance. However, little is known about the impact of empathy-focused problem formulation on students' perceptions of these problems. To explore these gaps, we studied students' perceptions of problem formulations in a 2 × 2 factorial between-subjects experiment. The problem formulations varied in (1) their socio-spatial context (i.e., positioned in the United States versus India) and (2) their empathy focus (i.e., with and without a persona). We measured the students' perceptions of the problem formulations using two metrics: (1) perceived psychological distance (i.e., socio-spatial, temporal, and hypothetical) and (2) perceived empathic response. We find that participants reported the problem contextualized in India to be a more immediate threat compared to the same problem set in the United States. Moreover, we find no significant differences in the other components of psychological distance or empathic response between the problem variants. This novel finding suggests that the studied sample perceives certain environmental issues as currently affecting people in other parts of the world, and not themselves, but only from a temporal lens. These findings call for educators to carefully consider temporal framing when using socio-spatially far sustainable design problems as a lack of consideration could create faulty perceptions of environmental issues.
Investigation of Three-Dimensional Wake Width for Offshore Wind Turbines Under Complex Environmental Conditions by Large Eddy Simulation
Authors: Liu Haixiao , Liu Mingqiu , Liang Zhichang
Published: July 2024

The wake of wind turbines is a main concern for offshore wind farms, in which the wake width is a key index and needs to be accurately predicted. However, the existing wake width models have shortcomings in predicting the wake of wind turbines in different offshore environments. In view of this, large eddy simulation (LES) is adopted to simulate offshore wind turbines under various environmental conditions. The analyses show that there are evident differences in wake widths between horizontal and vertical directions. The variations in turbulence intensity and wind speed in the environment have significant effects on the wake width. By fitting the simulation results, a three-dimensional (3D) wake width model is proposed to predict the wake widths in horizontal and vertical directions, which considers the effects of lateral and vertical turbulence intensities on the wake width in different directions, and uses the thrust coefficient to reflect the effect of wind speed. The proposed 3D model is then compared with existing models through test cases, indicating that it is more accurate in predicting wake widths in horizontal and vertical directions under different environmental conditions, meanwhile showing good applicability in complex offshore environments.
Effect of Variable Load on Centralized Dimple in an Opposite Sliding Condition
Authors: Du Hengrui , Wang Jing , Wang Xinqing
Published: July 2024

In ball bearings without a cage, adjacent balls exhibit a zero-entrainment velocity (ZEV) contact condition, which is worse than typical pure rolling or rolling–sliding contact, and the contact between adjacent balls under periodic loading is notably more complicated. In this work, thermal elastohydrodynamic lubrication (EHL) numerical calculation is carried out under the condition of periodic impact and opposite sliding line contact over a wide range of surface speeds. The pressure is solved by a multigrid method, the elastic deformation is evaluated using a multigrid integration method, and the temperature field is calculated by a column-by-column scanning technique. The results show that the loading–unloading process exerts significant influence on the variation of the centralized dimple, pressure, and temperature rises as well as the oil characteristics. With the increase of surface speed, the effect of load fluctuations diminishes, and the central dimple exhibits the following evolutionary trend under ZEV conditions: no dimple at very low velocity—small central dimple—large typical dimple—no dimple at high velocity. The result indicates that under the ZEV condition of EHL stage, elevated velocities decrease the coefficient of friction and augment the film thickness.
Effect of Thermal Conductivity on Maximum Film Pressure in Point Elastohydrodynamic Lubrication Contact of Ceramics With Transverse Surface Roughness
Authors: Kaneta Motohiro
Published: July 2024

Based on a fully flooded transient non-Newtonian thermoelastic fluid lubrication analysis of representative engineering ceramics and steels with different thermal conductivities and surface roughness, it is found that the material combination that causes the reduction of the maximum film pressure is closely related to the thermal conductivity of the contact materials and the surface temperature of the smooth-surfaced materials, and the maximum pressure reduction method is proposed. The results make a significant contribution to the design of mechanical elements involving contact between materials with different thermal conductivities and surface roughness.
Self-assembled oligomeric structures of an asymmetric molecular linker; 4-isocyanophenyl disulfide on Au(111)
Authors: Bavisotto Robert , Olson Dustin , Tysoe Wilfred T.
Published: July 2024

Para-substituted benzenes, such as 1,4-benzene dithiol and 1,4-phenyl diisocyanide, have been observed to oligomerize on the Au(111) surface by incorporating gold adatoms extracted from the substrate. This work investigates if oligomerization occurs for an analogous but asymmetric linker, 4-isocyanophenyl disulfide (ICPD) on Au(111). This molecule is comprised of both disulfide and isocyanide terminal groups attached to the phenyl ring. The resulting surface structures formed on Au(111) following exposure to ICPD are studied using scanning tunneling microscopy (STM). 1,4-isocyanophenyl thiolate (ICPT), formed through scission of ICPD’s disulfide bond, was also found to oligomerize on the surface, and potential oligomer structures and binding geometries are proposed with the aid of density functional theory (DFT) calculations, along with simulated STM images of the resulting structures. It is observed in this work that ICPT forms oligomeric structures that cover large sections of the substrate and appear to create etch pits resulting from gold atom extraction. Numerous potential binding geometries are investigated based on the distances between substrate gold atom adsorption sites compared to the monomer length. Selected structural candidates were optimized using DFT and were used to generate simulated STM images using the Tersoff–Hamann method to compare with experiment. It has been shown previously that the isocyanide- and thiol-connected oligomers conduct electrons, suggesting the possibility that the asymmetric oligomers found here might form the basis for fabricating molecular diodes.
Do Motor–Cognitive and Motor–Motor Dual-Task Training Differently Affect Dual-Task Interference in Individuals With Intellectual Disability?
Authors: Borji Rihab , Baccouch Rym , Laatar Rabeb , Falhi Sirine , Sahli Sonia , Rebai Haithem
Published: July 2024

This study explored the effect of different dual-task (DT) training programs on DT interference in adults with intellectual disability. Center-of-pressure (CoP) mean velocity in single-task (ST) and cognitive-DT conditions and the Timed Up-and-Go Test (TUGT) during ST, cognitive-DT, and motor-DT conditions were assessed before and after intervention in a cognitive–motor training group, a motor–motor training group, and a control group. Before training, CoP mean velocity and TUGT time increased (p < .001) in DT compared with the ST condition. After training, the CoP mean velocity values remained unchanged (p = .07) in DT compared with the ST condition among the cognitive–motor training group. Furthermore, compared with the ST condition, no increase (p = 1) was reported in the TUGT time during the cognitive-DT condition for the cognitive–motor training group and during the motor-DT for the motor–motor training group (p = .12). The effect of DT training on DT interference depends on the training modality.
Self-Reported Performance and Hormonal-Cycle-Related Symptoms in Competitive Female Athletes
Authors: Ihalainen Johanna K. , Takalo Sinikka , Mjøsund Katja , Solli Guro Strøm , Valtonen Maarit , Kokkonen Marja , Hackney Anthony C. , Mikkonen Ritva S.
Published: July 2024

Introduction: The present scientific consensus is that the menstrual cycle (MC) and hormonal contraceptive (HC) cycle only influence performance trivially. Nevertheless, athletes perceive changes in performance that they associate with different phases of their hormonal cycle. Methods: A total of 959 female athletes completed a questionnaire, of which 750 were included in the present analysis. The questionnaire included questions about demographics and experiences of the MC and HC (symptoms, perceived impact on performance characteristics). Results: In total, 55% of athletes reported a natural MC while 45% reported HC use. Meanwhile, 56% of all athletes reported a decline in perceived performance during the bleeding or inactive phase, whereas 26% of all athletes reported no changes in performance over their hormonal cycle. All athletes reported an average of 10 ± 7 symptoms during hormonal cycles. The naturally menstruating (NM) group reported more symptoms than the HC group (p < .05). The most frequent symptoms reported were abdominal pain, bloating, and mood swings. Only 7% of all athletes (4.1% in NM and 11.3% in HC) reported an absence of any symptoms. Quantity of total symptoms was associated with a perceived decrease in performance (R2 = .138, p < .05). Hormonal cycles had the greatest negative effect on mental performance with 37% reporting a large to very large effect. Conclusions: Perceived negative effects on performance were similar in both NM and HC groups while perceived mental performance (e.g., mood and attention) appeared to be most affected by both MC and HC.
A TrmBL2-like transcription factor mediates the growth phase-dependent expression of halolysin SptA in a concentration-dependent manner in
Natrinema gari
J7-2
Authors: Yin Jing , Liu Yang , He Dan , Li Ping , Qiao Mengting , Luo Hongyi , Qu Xiaoyi , Mei Sha , Wu Yi , Sun Yiqi , Gan Fei , Tang Bing , Tang Xiao-Feng
Published: July 2024

To cope with a high-salinity environment, haloarchaea generally employ the twin-arginine translocation (Tat) pathway to transport secretory proteins across the cytoplasm membrane in a folded state, including Tat-dependent extracellular subtilases (halolysins) capable of autocatalytic activation. Some halolysins, such as SptA of
Natrinema gari
J7-2, are produced at late-log phase to prevent premature enzyme activation and proteolytic damage of cellular proteins in haloarchaea; however, the regulation mechanism for growth phase-dependent expression of halolysins remains largely unknown. In this study, a DNA-protein pull-down assay was performed to identify the proteins binding to the 5′-flanking sequence of
sptA
encoding halolysin SptA in strain J7-2, revealing a TrmBL2-like transcription factor (NgTrmBL2). The Δ
trmBL2
mutant of strain J7-2 showed a sharp decrease in the production of SptA, suggesting that NgTrmBL2 positively regulates
sptA
expression. The purified recombinant NgTrmBL2 mainly existed as a dimer although monomeric and higher-order oligomeric forms were detected by native-PAGE analysis. The results of electrophoretic mobility shift assays (EMSAs) showed that NgTrmBL2 binds to the 5′-flanking sequence of
sptA
in a non-specific and concentration-dependent manner and exhibits an increased DNA-binding affinity with the increase in KCl concentration. Moreover, we found that a distal
cis
-regulatory element embedded in the neighboring upstream gene negatively regulates
trmBL2
expression and thus participates in the growth phase-dependent biosynthesis of halolysin SptA.

IMPORTANCE

Extracellular proteases play important roles in nutrient metabolism, processing of functional proteins, and antagonism of haloarchaea, but no transcription factor involved in regulating the expression of haloaechaeal extracellular protease has been reported yet. Here we report that a TrmBL2-like transcription factor (NgTrmBL2) mediates the growth phase-dependent expression of an extracellular protease, halolysin SptA, of haloarchaeon
Natrinema gari
J7-2. In contrast to its hyperthermophilic archaeal homologs, which are generally considered to be global transcription repressors, NgTrmBL2 functions as a positive regulator for sptA expression. This study provides new clues about the transcriptional regulation mechanism of extracellular protease in haloarchaea and the functional diversity of archaeal TrmBL2.
ROK family regulator NagC promotes prodigiosin biosynthesis independent of
N
-acetylglucosamine in
Serratia
sp. ATCC 39006
Authors: Liu Weijie , Shi Rui , Zhang Ying , Li Chenchen , Zhou Xuge , Jensen Marcus Sepo , Yang Jing , Zhao Siyi , Liu Jiawen , Zhu Jingrong , Liu Cong , Sun Di
Published: July 2024

Serratia
sp. ATCC 39006 is an important model strain for the study of prodigiosin production, whose prodigiosin biosynthesis genes (
pigA-O
) are arranged in an operon. Several transcription factors have been shown to control the transcription of the
pig
operon. However, since the regulation of prodigiosin biosynthesis is complex, the regulatory mechanism for this process has not been well established. In most γ-proteobacteria, the ROK family regulator NagC acts as a global transcription factor in response to
N
-acetylglucosamine (GlcNAc). In
Serratia
sp. ATCC 39006, NagC represses the transcription of two divergent operons,
nagE
and
nagBAC
, which encode proteins involved in the transport and metabolism of GlcNAc. Moreover, NagC directly binds to a 21-nt region that partially overlaps the −10 and −35 regions of the
pig
promoter and promotes the transcription of prodigiosin biosynthesis genes, thereby increasing prodigiosin production. Although NagC still acts as both repressor and activator in
Serratia
sp. ATCC 39006, its transcriptional regulatory activity is independent of GlcNAc. NagC was first found to regulate antibiotic biosynthesis in Gram-negative bacteria, and NagC-mediated regulation is not responsive to GlcNAc, which contributes to future studies on the regulation of secondary metabolism by NagC in other bacteria.

IMPORTANCE

The ROK family transcription factor NagC is an important global regulator in the γ-proteobacteria. A large number of genes involved in the transport and metabolism of sugars, as well as those associated with biofilm formation and pathogenicity, are regulated by NagC. In all of these regulations, the transcriptional regulatory activity of NagC responds to the supply of GlcNAc in the environment. Here, we found for the first time that NagC can regulate antibiotic biosynthesis, whose transcriptional regulatory activity is independent of GlcNAc. This suggests that NagC may respond to more signals and regulate more physiological processes in Gram-negative bacteria.
Expansion of Auxiliary Activity Family 5 sequence space via biochemical characterization of six new copper radical oxidases
Authors: Fong Jessica K. , Mathieu Yann , Vo Minh Tri , Bellemare Annie , Tsang Adrian , Brumer Harry
Published: July 2024

Bacterial and fungal copper radical oxidases (CROs) from Auxiliary Activity Family 5 (AA5) are implicated in morphogenesis and pathogenesis. The unique catalytic properties of CROs also make these enzymes attractive biocatalysts for the transformation of small molecules and biopolymers. Despite a recent increase in the number of characterized AA5 members, especially from subfamily 2 (AA5_2), the catalytic diversity of the family as a whole remains underexplored. In the present study, phylogenetic analysis guided the selection of six AA5_2 members from diverse fungi for recombinant expression in
Komagataella pfaffii
(syn.
Pichia pastoris
) and biochemical characterization
in vitro
. Five of the targets displayed predominant galactose 6-oxidase activity (EC 1.1.3.9), and one was a broad-specificity aryl alcohol oxidase (EC 1.1.3.7) with maximum activity on the platform chemical 5-hydroxymethyl furfural (EC 1.1.3.47). Sequence alignment comparing previously characterized AA5_2 members to those from this study indicated various amino acid substitutions at active site positions implicated in the modulation of specificity.

IMPORTANCE

Enzyme discovery and characterization underpin advances in microbial biology and the application of biocatalysts in industrial processes. On one hand, oxidative processes are central to fungal saprotrophy and pathogenesis. On the other hand, controlled oxidation of small molecules and (bio)polymers valorizes these compounds and introduces versatile functional groups for further modification. The biochemical characterization of six new copper radical oxidases further illuminates the catalytic diversity of these enzymes, which will inform future biological studies and biotechnological applications.
Clostridioides difficile
superoxide reductase mitigates oxygen sensitivity
Authors: Kochanowsky Rebecca , Carothers Katelyn , Roxas Bryan Angelo P. , Anwar Farhan , Viswanathan V. K. , Vedantam Gayatri
Published: July 2024

Clostridioides difficile
causes a serious diarrheal disease and is a common healthcare-associated bacterial pathogen. Although it has a major impact on human health, the mechanistic details of
C. difficile
intestinal colonization remain undefined.
C. difficile
is highly sensitive to oxygen and requires anaerobic conditions for
in vitro
growth. However, the mammalian gut is not devoid of oxygen, and
C. difficile
tolerates moderate oxidative stress
in vivo
. The
C. difficile
genome encodes several antioxidant proteins, including a predicted superoxide reductase (SOR) that is upregulated upon exposure to antimicrobial peptides. The goal of this study was to establish SOR enzymatic activity and assess its role in protecting
C. difficile
against oxygen exposure. Insertional inactivation of
sor
rendered
C. difficile
more sensitive to superoxide, indicating that SOR contributes to antioxidant defense. Heterologous
C. difficile sor
expression in
Escherichia coli
conferred protection against superoxide-dependent growth inhibition, and the corresponding cell lysates showed superoxide scavenging activity. Finally, a
C. difficile
SOR mutant exhibited global proteome changes under oxygen stress when compared to the parent strain. Collectively, our data establish the enzymatic activity of
C. difficile
SOR, confirm its role in protection against oxidative stress, and demonstrate SOR’s broader impacts on the
C. difficile
vegetative cell proteome.

IMPORTANCE

Clostridioides difficile
is an important pathogen strongly associated with healthcare settings and capable of causing severe diarrheal disease. While considered a strict anaerobe
in vitro
,
C. difficile
has been shown to tolerate low levels of oxygen in the mammalian host. Among other well-characterized antioxidant proteins, the
C. difficile
genome encodes a predicted superoxide reductase (SOR), an understudied component of antioxidant defense in pathogens. The significance of the research reported herein is the characterization of SOR’s enzymatic activity, including confirmation of its role in protecting
C. difficile
against oxidative stress. This furthers our understanding of
C. difficile
pathogenesis and presents a potential new avenue for targeted therapies.