bluuebunny/crossref_metadata_2025 huggingface dataset:
Competencies of dental public health for undergraduate students and their self‐perceived achievements: The case of Iran
Authors: Asgari Imaneh , Karimi Shirin , charmdooz Niloofar , Tahani Bahareh
Published: December 2021

Purpose

The aim of this study was to develop Dental Public Health (DPH) competencies and to assess the self‐perceived achievements of undergraduate students in regard to these competencies.

Materials and Methods

In the first phase, by using the mixed method of the RAND‐UCLA model, a list of the proposed competencies was developed and validated based on three‐round expert consensus using both rating and group discussing method. In the second phase, 120 senior (final‐year) dental students were asked to determine their achievements based on the finalised list of competency statements on a 0–10 numerical scale. Descriptive statistical analysis was then performed using SPSS (version 22) to determine the mean score of the items and domains. Some background factors were also tested for any relationship.

Result

After three rounds of implementing the RAND‐UCLA method, 31 statements in 10 domains were developed and validated. The mean total score of the self‐reported competency was 176.87 ± 52.4 amongst the recruited dental students with a range of 37 to 304. The highest mean ± sd score (7.7 ± 1.8) was found for the preventive oral health services field, whilst the lowest one (4.5 ± 2.3) was reported for understanding the components and functions of the health system. The average self‐reported scores of professional ethics and professionalism, evidence‐based practice and oral health determinants were also acceptable amongst them.

Conclusion

The finalised competencies gained the consensus level of agreement and appropriateness by representatives of all DPH experts in the country. However, according to the dental students’ self‐reports, they had moderate competencies in most cases. Therefore, content and applied methods of training and evaluation may need to be revised to support students’ development. Also, the complementary evaluation method at real work setting is highly suggested.
Impact of the COVID‐19 pandemic on Creutzfeldt–Jakob disease surveillance and patient care in the United Kingdom
Authors: Watson Neil , Kirby Jack , Kurudzhu Hatice , Leitch Margaret , MacKenzie Janet , Smith‐Bathgate Blaire , Smith Colin , Summers David , Green Alison J. E. , Pal Suvankar
Published: December 2021

Background and purpose

Creutzfeldt–Jakob disease (CJD) is lethal and transmissible. We assessed the impact of the COVID‐19 pandemic on UK CJD surveillance. We hypothesized that (i) disruptions prolonged diagnostic latency; (ii) autopsy rates declined; and (iii) COVID‐19 infection negatively affected diagnosis, care, and survival.

Methods

We retrospectively investigated the first year of the pandemic, using the preceding year as a comparator, quantifying numbers of individuals assessed by the UK National CJD Research & Surveillance Unit for suspected CJD, time to diagnosis, disease duration, and autopsy rates. We evaluated the impact of COVID‐19 status on diagnosis, care, and survival in CJD.

Results

A total of 148 individuals were diagnosed with CJD in the pandemic (from a total of 166 individuals assessed) compared to 141 in the comparator (from 145 assessed). No differences were identified in disease duration or time to diagnosis. Autopsy rates were unchanged. Twenty individuals had COVID‐19; 60% were symptomatic, and 10% had severe disease. Disruptions in diagnosis and care were frequently identified. Forty percent of COVID‐19‐positive individuals died; however, COVID‐19 status did not significantly alter survival duration in CJD.

Conclusions

The COVID‐19 pandemic has not impacted UK CJD case ascertainment or survival, but diagnostic evaluation and clinical care of individuals have been affected.
The longitudinal links between marital conflict and Chinese children’s internalizing problems in mainland China: Mediating role of maternal parenting styles
Authors: Xiao Bowen , Bullock Amanda , Liu Junsheng , Coplan Robert J.
Published: December 2021

The present study explored the role of parenting styles as mediating mechanisms in the link between marital conflict and Chinese children's internalizing problems. Participants were N = 1269 families (mothers, fathers, and children) from Shanghai, P. R. China. Multisource assessments were employed at three time points. Mothers and fathers reported their marital conflict and parenting styles (authoritative, authoritarian) and teachers and children reported on children's internalizing problems. Results from the Actor–Partner Interdependence Model (APIM) showed significant actor and partner effects for associations between marital conflict and parenting styles. After controlling for internalizing problems at Time 1, only maternal authoritarian parenting continued to mediate the relations between mothers’ reported marital conflict and change in children's internalizing problems over time. This research provides valuable information about how important aspects of parenting influence the relations between marital conflict and internalizing problems among Chinese children.
Identification of cohesive zone model parameters based on interface layer displacement field of bonded joints
Authors: Cricrì Gabriele , Perrella Michele , Berardi Valentino Paolo
Published: December 2021

Nowadays, adhesively bonded structures are widely used as structural elements in many engineering fields. The development of approaches for predicting joint reliability and interface layer behavior make adhesives suitable for new and more complex applications. In this paper, a novel identification methodology of cohesive zone model (CZM) parameters, based on the comparison of experimental and numerical relative adherends slip displacements, is proposed and compared with approaches by literature. All considered methods are based on an interface traction–separation law (TSL) whose shape is known a priori. For identification purposes, tests on adhesively bonded joints under Mode II fracture loading were performed using end notched flexure (ENF) specimen. Experimental results in terms of relative adherends tangential slips were obtained by means of digital image correlation (DIC) technique.
Willingness to pay taxes through mutual trust: The effect of fairness, governability,tax‐enforcementand outsourcing on local tax collection rates
Authors: Beeri Itai , Zaidan Akab , Zeedan Rami
Published: December 2021

This study extends our understanding about the interrelationship between taxation policy, democracy and financial performance in local governments. Every government, particularly local ones, would like to make their residents more willing to pay taxes. Based on the trend of making local authorities less reliant on national budgets and the ever‐increasing expectations that they provide high quality services, we investigated how public perceptions about the local government's fairness, tax enforcement, governability and the outsourcing of local tax collection affect the percentage of local property taxes collected. We used a survey of 607 Israeli residents randomly sampled from municipalities that do and do not outsource, and independent data about tax collection rates. The results indicate that perceptions about tax enforcement and governability mediate the relationship between perceptions about fairness and tax collection rates. However, only within local authorities that outsourced tax collection was there a positive relationship between perceptions about tax enforcement and tax collection rates and a positive relationship between perceptions about governability and tax collection rates. Implications of the findings are discussed in the era of local democracy and local governance.
Differential antigenic requirements by diverse MR1‐restricted T cells
Authors: Seneviratna Rebecca , Redmond Samuel J , McWilliam Hamish EG , Reantragoon Rangsima , Villadangos Jose A , McCluskey James , Godfrey Dale I , Gherardin Nicholas A
Published: December 2021

MHC‐related protein 1 (MR1) presents microbial riboflavin metabolites to mucosal‐associated invariant T (MAIT) cells for surveillance of microbial presence. MAIT cells express a semi‐invariant T‐cell receptor (TCR), which recognizes MR1–antigen complexes in a pattern‐recognition‐like manner. Recently, diverse populations of MR1‐restricted T cells have been described that exhibit broad recognition of tumor cells and appear to recognize MR1 in association with tumor‐derived self‐antigens, though the identity of these antigens remains unclear. Here, we have used TCR gene transfer and engineered MR1‐expressing antigen‐presenting cells to probe the MR1 restriction and antigen reactivity of a range of MR1‐restricted TCRs, including model tumor‐reactive TCRs. We confirm MR1 reactivity by these TCRs, show differential dependence on lysine at position 43 of MR1 (K43) and demonstrate competitive inhibition by the MR1 ligand 6‐formylpterin. TCR‐expressing reporter lines, however, failed to recapitulate the robust tumor specificity previously reported, suggesting an importance of accessory molecules for MR1‐dependent tumor reactivity. Finally, MR1‐mutant cell lines showed that distinct residues on the α1/α2 helices were required for TCR binding by different MR1‐restricted T cells and suggested central but distinct docking modes by the broad family of MR1‐restricted αβ TCRs. Collectively, these data are consistent with recognition of distinct antigens by diverse MR1‐restricted T cells.
No association of Gaucher disease with COVID‐19‐related outcomes: a nationwide cohort study
Authors: Demirci Ibrahim , Demir Tevfik , Dagdelen Selcuk , Haymana Cem , Tasci Ilker , Atmaca Aysegul , Ertugrul Derun , Ata Naim , Sahin Mustafa , Salman Serpil , Sahin Ibrahim , Emral Rifat , Unluturk Ugur , Cakal Erman , Celik Osman , Caglayan Murat , Satman Ilhan , Sonmez Alper
Published: December 2021

Background

It is well documented that patients with chronic metabolic diseases, such as diabetes and obesity, are adversely affected by the COVID‐19 pandemic. However, when the subject is rare metabolic diseases, there are not enough data in the literature.

Aim

To investigate the course of COVID‐19 among patients with Gaucher disease (GD), the most common lysosomal storage disease.

Methods

Based on the National Health System data, a retrospective cohort of patients with confirmed (polymerase chain reactionpositive) COVID‐19 infection (n = 149 618) was investigated. The adverse outcomes between patients with GD (n = 39) and those without GD (n = 149 579) were compared with crude and propensity score‐matched (PSM) groups. The outcomes were hospitalisation, the composite of intensive care unit (ICU) admission and/or mechanical ventilation and mortality.

Results

The patients with GD were significantly older and had a higher frequency of hypertension (HT), Type 2 diabetes mellitus (T2DM), dyslipidaemia, asthma or chronic obstructive pulmonary disease, chronic kidney disease, coronary artery disease, heart failure and cancer. Although hospitalisation rates in Gaucher patients were found to be higher in crude analyses, the PSM models (model 1, age and gender matched; model 2, matched for age, gender, HT, T2DM and cancer) revealed no difference for the outcomes between patients with GD and the general population. According to multivariate regression analyses, having a diagnosis of GD was not a significant predictor for hospitalisation (P = 0.241), ICU admission/mechanical ventilation (P = 0.403) or mortality (P = 0.231).

Conclusion

According to our national data, SARS‐CoV‐2 infection in patients with GD does not have a more severe course than the normal population.
Tag retention in and effects of passive integrated transponder tagging on survival and swimming performance of a small‐bodied darter
Authors: Swarr Tyler R. , Myrick Christopher A. , Fitzpatrick Ryan M.
Published: December 2021

Fisheries biologists have been hesitant to use passive integrated transponder (PIT) tags in small‐bodied fishes (40–200 mm TL) such as darters (Percidae: Etheostomatinae) because of the fishes' size and potential effect on swimming performance. The authors used constant acceleration trials to evaluate the swimming performance of Arkansas darters Etheostoma cragini in control (no incision or tag), sham (incision and suture) or PIT tagged (surgically implanted 8 × 1.4 mm intra‐peritoneal PIT tag) treatments. Tag retention and fish survival were monitored for up to 199 days post‐tagging. Maximum swimming velocity did not differ between control, sham and PIT tag treatments, nor was maximum swimming velocity affected by the tagging procedure. Tag retention was 100%, and the overall survival of tagged fish was 88% in the swimming study, and 100% in the long‐term study, suggesting that small PIT tags are suitable for use in darters. The authors include a brief meta‐analysis on the results reported by 20 studies that PIT tagged small‐bodied fishes, representing 38 species and nine families of freshwater fish.
A pilot‐scale rotary infrared dryer of shrimp (Metapenaeus affinis): Mathematical modeling and effect on physicochemical attributes
Authors: Al‐Hilphy Asaad R. , Al‐Mtury Atheer Abdul Amir , Al‐Iessa Sajedah A. , Gavahian Mohsen , Al‐Shatty Sabah Malik , Jassim Muhammad Ali , Mohusen Zainab Abdul Ameer , Mousavi Khaneghah Amin
Published: December 2021

A new rotary infrared dryer (R.I.D.) was manufactured to dry shrimp (Metapenaeus affinis) at 60, 70, and 80°C. Also, mathematical modeling along with artificial neural networks (ANNs) was used for data prediction. The results showed that the exponential proposed model and ANN could be applied to well‐predict the moisture ratio of shrimp. Besides, running R.I.D. at 80°C resulted in the highest reduction in moisture content and saved about 42% of drying time. The thermal efficiency of the R.I.D. at a temperature of 70°C ranged between 83 and 89%, which was about 15% higher than the conventional dryer. The drying rate by both R.I.D. and conventional methods consist of a falling rate period, ranging between 1.68 × 10−4 and 0.47 × 10−4 1/s. Furthermore, the mass transfer coefficient increased by about 104.6% when drying temperature increased from 60 to 80°C. The browning index increased with the increase of drying temperature. Specific energy consumption, browning index, and drying time of rotary infrared system were lower than those of conventional system by 46.9, 33.3, and 34.7%, respectively. R.I.D. reduced energy consumption, decreased the color changes, improved the rehydration ratio, and affected the chemical composition of dried shrimp as compared with the conventional process.

Practical Applications

A new rotary infrared dryer was designed and developed and its performance was evaluated with the assistance of artificial neural networks. This system was shown to be energy‐ and time‐saving and capable of producing high‐quality dry shrimp (Metapenaeus affinis). Also, the system is simple and affordable due to reducing energy consumption and relatively low cost of components. Therefore, it has the potential to be used in the industry after further economic and technical evaluation.
Microcephaly gene Cenpj regulates axonal growth in cortical neurons through microtubule destabilization
Authors: Meneses Iack Pamela , Rayêe Danielle , Lent Roberto , Ribeiro‐Resende Victor Túlio , Garcez Patrícia P.
Published: December 2021

Neocortex development comprises of a complex series of time‐ and space‐specific processes to generate the typical interconnected six‐layered architecture of adult mammals. Axon growth is required for the proper establishment of cortical circuits. Malformations in axonal growth and pathfinding might lead to severe neuropathologies, such as corpus callosum dysgenesis. Cenpj, a microcephaly gene, encodes a scaffold protein that regulates centrosome biogenesis and microtubule stabilization. During corticogenesis, Cenpj regulates progenitor division and neuronal migration. Since microtubule stabilization is crucial for axon extension, we investigated the role of Cenpj in axon growth during cortical development in a mouse model. Through loss‐ and gain‐of‐function assays ex vivo and in utero, we quantified callosal axonal length, branching, and growth cone size compared to controls. We observed that silencing Cenpj results in an increased axonal length. Ex vivo, we assessed the number of branches, the area of growth cones and the stability of microtubules. In silenced Cenpj axons, there were more branches, larger growth cone area, and more stable microtubules. Rescue experiments confirmed that neurons present axonal length comparable to controls. Here we propose that Cenpj regulates axon growth by destabilizing microtubules during cortical development. Finally, our findings suggest that Cenpj might be a novel target for axonal regeneration.

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Incomplete Institutional Change and the Persistence of Racial Inequality: The Contestation of Institutional Misalignment in South Africa*
Authors: Adams Ansellia , Luiz John M.
Published: December 2021

This study explores the role that organizations and institutions play in reproducing inequality even after significant political transitions intended to undermine the sources of such inequality. Our analysis reveals how incomplete institutional transitions may give rise to contradictory institutional logics and how this can contribute to high levels of contestation as actors and organizations vie to maintain, disrupt, and create new institutions. We analyse the dynamics of a conflict set within a broader institutional contestation in post‐apartheid South Africa by examining the farmworkers strike and unrest of 2012. We expose a complex interlocking system of exploitation and oppression at micro, meso, and macro institutional levels and highlight misalignments between de facto and de jure institutional environments. Our study shows how actors and organizations can exhibit and constrain agency legitimating the unequal access to resources and opportunities and why this can result in the persistence of inequality.
Are dental‐related psychological variables important for dental attendance in China? A cross‐sectional study
Authors: Wu Lei , Buchanan Heather , Topcu Gogem
Published: December 2021

Objective

Dental services are expanding in China, yet there is little evidence available on the dental‐related psychological factors contributing to the uptake of dental services. Our study explored whether beliefs, anxiety, and cognitions significantly differ across different levels of attendance, and whether dental‐related psychological variables can independently predict dental attendance in Chinese adults. We also explored the extent to which cognitions and beliefs relate to attendance as a function of dental anxiety.

Method

In our cross‐sectional study 480 adult participants in China completed a questionnaire including dental attendance and measures of dental‐related psychological variables (dental cognitions, beliefs, anxiety, and fear of dental pain).

Results

Only 25.8% of participants visited the dentist regularly. There was a significant difference for all dental‐related psychological variables (p < 0.001), across all three levels of dental attendance (never; irregularly or regularly attend). Thus, fear of dental pain and dental anxiety are higher, and cognitions and beliefs are more negative, for those who have less favorable dental service utilization. All these variables, except fear of dental pain, were also independent predictors of dental attendance (p < 0.05). Moreover, how individuals think, and what they believe, about the dentist (and the dental context) were only partially explained through dental anxiety. Thus, beliefs (β = 0.579, SE = 0.035, p < 0.001) and cognitions (β = 0.594, SE = 0.045, p < 0.001) are impacting on dental attendance, mostly independent of whether the individual is anxious.

Conclusion

Our preliminary findings show dental‐related psychological factors are related to dental attendance and these should be explored further in a larger sample.
Glycogen storage disease in a young cat with heart failure
Authors: Tanaka Shigeki , Suzuki Ryohei , Koyama Hidekazu , Machida Noboru , Yabuki Akira , Yamato Osamu
Published: December 2021

An 8‐month‐old domestic short‐haired female cat presented with acute tachypnea, poor growth, hypothermia, and lethargy. Thoracic radiography showed cardiomegaly with mild pleural effusion, and transthoracic echocardiography identified dilatation of both atria and left ventricular systolic dysfunction. Although clinical signs improved temporarily with treatment, the cat died of pulmonary edema 135 days after the first visit. At necropsy, the heart was grossly enlarged. Microscopic examination of the heart identified severe vacuolization of cardiac muscle cells in histologic sections stained with hematoxylin and eosin. Examination of periodic acid‐Schiff stained preparations of formalin‐fixed heart tissue disclosed coarse granules within vacuoles that disappeared on predigestion with diastase, indicating that they were glycogen. On the basis of these findings, a necropsy diagnosis of glycogen storage disease type II (Pompe disease) was made. This report is the first case of a young cat with clinical signs closely resembling infantile Pompe disease of humans.
Who's on your team? Specialty identity and inter‐physician conflict during admissions
Authors: Schrepel Caitlin , Amick Ashley E. , Bann Maralyssa , Watsjold Bjorn , Jauregui Joshua , Ilgen Jonathan S. , Sebok‐Syer Stefanie S.
Published: December 2021

Purpose

Despite the implementation of professionalism curricula and standardised communication tools, inter‐physician conflict persists. In particular, the interface between emergency medicine (EM) and internal medicine (IM) has long been recognised as a source of conflict. The social nuances of this conflict remain underexplored, limiting educators' ability to comprehensively address these issues in the clinical learning environment. Thus, the authors explored EM and IM physicians' experiences with negotiating hospital admissions to better understand the social dynamics that contribute to inter‐physician conflict and provide foundational guidance for communication best practices.

Methods

Using a constructivist grounded theory (CGT) approach, the authors conducted 18 semi‐structured interviews between June and October 2020 with EM and IM physicians involved in conversations regarding admissions (CRAs). They asked participants to describe the social exchanges that influenced these conversations and to reflect on their experiences with inter‐physician conflict. Data collection and analysis occurred iteratively. The relationships between the codes were discussed by the research team with the goal of developing conceptual connections between the emergent themes.

Results

Participants described how their approaches to CRAs were shaped by their specialty identity, and how allegiance to members of their group contributed to interpersonal conflict. This conflict was further promoted by a mutual sense of disempowerment within the organisation, misaligned expectations, and a desire to promote their group's prerogatives. Conflict was mitigated when patient care experiences fostered cross‐specialty team formation and collaboration that dissolved traditional group boundaries.

Conclusions

Conflict between EM and IM physicians during CRAs was primed by participants' specialty identities, their power struggles within the broader organisation, and their sense of duty to their own specialty. However, formation of collaborative inter‐specialty physician teams and expansion of identity to include colleagues from other specialties can mitigate inter‐physician conflict.
Direct relations between sense of coherence and oral health‐related quality of life in adolescents
Authors: Tondolo Junior Jocelito , Ortiz Fernanda Ruffo , Ramadan Yassmín Hêllwaht , Maroneze Marília Cunha , Agostini Bernardo Antonio , Ardenghi Thiago Machado
Published: December 2021

Objective

To verify the relations between sense of coherence (SOC) and dental caries on oral health‐related quality of life (OHRQoL) of adolescents.

Subject and Methods

A cross‐sectional sample of 768 adolescents nested in a cohort study was evaluated. SOC was measured using Antonovsky's scale. Dental caries was collected considering the decayed, missing, and filled teeth index (DMFT). OHRQoL was collected through the Child Perception Questionnaire. Demographic, socioeconomic, and use of service variables were also collected. The mediation effects between variables were tested by structural equation modeling.

Results

The average age of the individuals was 17.5 years. Individuals with high SOC scores had a positive impact on OHRQoL (β‐coefficient = −0.573, p < 0.00). Individuals with high DMFT (β‐coefficient = 0.080, p = 0.034) and dental pain (β‐coefficient = 0.079, p = 0.039) negatively impacted OHRQoL. Still, adolescents who had dental pain (β‐coefficient = 0.112, p = 0.005), mothers with lower education levels (β‐coefficient = −0.114, p = 0.004), lower household income (β‐coefficient = −0.131, p = 0.003), and those who visited the dentist (β‐coefficient = 0.109, p = 0.005) exhibited a higher DMFT index.

Conclusions

SOC and dental caries had a direct effect on OHRQoL, indicating that oral conditions and psychosocial characteristics are important contributors to OHRQoL.
Crude oil production and macroeconomic performance in Ghana
Authors: Tunyo Delali Aku , Armah Mark , Cantah William Godfred , Suleman Shafic
Published: December 2021

The objective of this study was to investigate the impact of crude oil production on macroeconomic performance in Ghana. The study employed monthly data from January 2011 to December 2018. The structural vector autoregressive model was employed to analyse the impact of crude oil production on macroeconomic performance. The findings of the structural impulse response function revealed that crude oil production had no impact on the agricultural sector, services sector, exchange rate and inflation. However, crude oil production had a negative and positive impact on the manufacturing sector and fiscal balance, respectively. The findings imply that the government through Ghana National Petroleum Corporation (GNPC) and other major oil stakeholders should establish oil refineries, petroleum industries and fertiliser plants domestically to provide a forward linkage for the non‐oil sectors. Also, the government through the Ministry of Trade and Industry should develop the services sectors to meet international standards to provide a backward linkage to the oil sector and ensure the integration of the sectors into the oil industry. The government needs to intensify measures to make the manufacturing sector recover from the adverse effect of the production of crude oil.
Conciliatory strategies in philosophy
Authors: Barceló Aspeitia Axel Arturo
Published: December 2021

In philosophy, as in any other theoretical endeavor, it is not rare to find conflicting but equally well grounded positions. Besides defending one of the positions and criticizing the other, philosophers can opt for pursuing other, more sophisticated, approaches aimed at incorporating the insights, intuitions, and arguments from both sides of the debate into a unified theory: Dialetheism, Analetheism, Gradualism, Pluralism and Relativism. The purpose of this article is to present each strategy's basic argumentative structure, relative strengths, and challenges, trying to determine in which situations one is more appropriate than the others. Despite substantial differences between them, all four options have deep structural similarities; and which option is better for which dilemma or paradox will depend ultimately on a combination of epistemological, linguistic, and metaphysical factors.
Clinical associations of serum Golgi apparatus antibodies in an immunology laboratory cohort
Authors: Lee Adrian Y. S. , Culican Suzanne , Campbell David , Lin Ming‐Wei
Published: December 2021

Introduction

Anti‐Golgi antibodies (AGAs) are rare antibodies that are found as distinct, polarised cytoplasmic staining on the HEp‐2 substrate.

Methods

We performed a review of patients that demonstrated this autoantibody in a large laboratory cohort in Australia. Over a 24‐month period, all patients that had a sample submitted for routine antinuclear antibodies (ANAs) that had AGA staining were retrospectively identified. Medical records were perused to identify clinical associations.

Results

There were 23 813 ANAs identified with 34 patients (0.14%) demonstrating AGA staining. AGAs were found in a variety of inflammatory disorders, malignancies and liver diseases. They did not associate with any other significant ANA, and in contrast with previous studies, we did not find any association with systemic autoimmune rheumatic diseases.

Conclusions

Anti‐Golgi antibodies are rare, non‐specific and possibly a bystander phenomenon. Future studies are required to study the origin and longitudinal clinical associations of these autoantibodies.
Assessment of the heterogeneous microstructure in the vicinity of a weld using thermographic measurements of the full‐field dissipative heat source
Authors: Jaya Seelan Palaniappan , Pierron Fabrice , Dulieu‐Barton Janice M.
Published: December 2021

During a material deformation process, part of the mechanical energy is dissipated as heat due to thermodynamically irreversible processes occurring at the microscale of the material. In particular, part of the plastic deformation energy is transformed into heat and is referred to as ‘intrinsic dissipation’ as it is intrinsic to the material behaviour. The intrinsic dissipation is a heat source that is sensitive to microstructural states which can be used to identify different microstructural regions resulting from material processing such as welding. To determine the heat source in a full‐field manner, it is necessary to use an infrared camera to measure any temperature rise in a specimen undergoing elastic cyclic loading. Unlike the intrinsic dissipative heat source, the temperature change is sensitive to thermal exchanges with the surroundings. Hence, the thermomechanical heat diffusion equation is used to determine the full‐field dissipative heat from the thermographic temperature measurement by implementing an image processing procedure based on least squares fitting enabled by specially devised experimental approach. The procedure is verified by deriving both the thermoelastic and dissipative heat sources from a ‘hole‐in‐plate’ specimen manufactured from 316L stainless steel, that is, a specimen with a known stress distribution. The approach is then applied to a 316L laser welded specimen, and it is demonstrated that the different microstructures resulting from the welding process can be identified with the procedure. The heterogeneous microstructure is confirmed using micrographs and further verified by the different stress–strain behaviour obtained for each microstructural region using digital image correlation (DIC).
Amphiphilic Zirconium Phosphate Nanoparticles as Tribo-Catalytic Additives of Multi-Performance Lubricants
Authors: Chen Yan , Wang Xuezhen , Han Zehua , Sinyukov Alexander , Clearfield Abraham , Liang Hong
Published: December 2021

The advancement of electric vehicles demands lubricants with multifunction and performance. In this research, we investigated amphiphilic ZrP nanoparticles as lubricant additives. Experiments showed that the nanolubricant produced a tribofilm reduced the friction for 40% and wear 90%, while the electrical conductivity remained to be stable during tribotesting. Surface characterization of the tribofilm showed that there was a layered pyrophosphate on the wear track. The in situ impedance study about tribochemical kinetics revealed that the process in formation of a tribofilm involved simultaneous growth and wear. During growth, the coefficient of friction increased with continued formation of such film. During wear, the material removal rate was a function of friction, i.e., the higher the wear-rate, the higher the friction coefficient. The competing mechanisms of film growth and wear resulted in an electrically uniformed surface.
A Fast Thermoelastic Model Based on the Half-Space Theory Applied to Elastohydrodynamic Lubrication of Line Contacts Involving Free Boundaries
Authors: Yalpanian Ali , Guilbault Raynald
Published: December 2021

This study allows contact models based on semi-analytical methods including the impacts of thermoelastic deformations in contacts of finite dimension bodies. The proposed method controls heat flows crossing free boundaries. A comparison with finite element analysis (FEA) reveals that the proposed method can reduce the calculation times by more than 98%. The paper introduces the thermoelasticity effects into thermal-elastohydrodynamic lubrication (TEHL) modeling of line contact problems. The analysis reveals that including thermoelastic deformations changes the pressure profile and tends to localize the pressure close to the distribution center. Compared to TEHL simulations, the examined configurations caused an overall increase in the maximum pressure by about 9%, an overall film thickness reduction of about 7%, and an overall temperature increase of about 2 K.
The Sinking of the R.M.S. Titanic: A Case Study in Thermal Inversion and Atmospheric Refraction Phenomena
Authors: DiLisi Gregory A.
Published: December 2021

On April 14, 1912, the British passenger liner R.M.S. Titanic struck an iceberg. The ship sank in a fraction of the time designers had estimated following a worst case scenario. The purpose of this article is to examine the atmospheric refractive phenomena that might have played a significant role in obscuring the iceberg from Titanic’s two lookouts. We describe a way in which these phenomena can easily and inexpensively be brought to students in our introductory physics classrooms.
Pictures of Signs in Sea Waves
Authors: Razpet Nada , Kranjc Tomaz
Published: December 2021

In nature, we often observe interesting phenomena for which we would like to find a physical explanation. One such phenomenon is presented in this paper.
Science Conferences: A Pathway for Enacting the NGSS
Authors: Wargo Brian M.
Published: December 2021

The Next Generation Science Standards (NGSS) is the latest initiative to promote authentic scientific work in the classroom. Previous reform efforts have not caused the change in teacher practice and student learning that was hoped for, despite their ubiquity and accessibility. The culprit may be the culture of school that is often recalcitrant to change. This article argues that the NGSS may be the most scientifically aligned reform but may be doomed to failure unless it can be connected with the culture of schooling. The central idea offered here is to incorporate the professional practice espoused in the NGSS by using a cultural emblem of school science—the science fair. The trick is to transform the science fair into a science conference.
The Sound of a Laser Blaster: Acoustic Dispersion in Metal Springs Analyzed with Mobile Devices and Open-Source PC Audio Software
Authors: Ludwig-Petsch Kim , Hirth Michael , Kuhn Jochen
Published: December 2021

The typical sound of George Lucas’ laser blaster in the “Star Wars” series is well known. What does a laser blaster in “Star Wars” sound like, and why? Here we show a simple way to produce this sound by using low-cost lab material, like a spring or a Slinky (Fig. 1). Building on the work of Crawford, who analyzed the sound of a Slinky using oscilloscopes, we present a technique for analyzing the sound using mobile devices. For a deeper quantitative analysis, a PC with open-source software is used.
Going “All Quantitative” While Teaching About Light and Stars in Introductory Astronomy
Authors: LoPresto Michael
Published: December 2021

When teaching a general education introductory astronomy course that includes a mathematics prerequisite, it is important to convey that formulas and equations physically represent properties of actual objects and processes that occur that can actually be observed. Students with varying comfort levels with mathematics often need to be convinced that problems involving formulas and equations are more than simply mathematical exercises, but are meant to enhance their understanding of the physical concepts. One way to attempt to do this is to introduce equations related to concepts that are being studied qualitatively, for instance, with lecture-tutorials. Here are several examples making use of lecture-tutorials on topics related to light and stars from the popular manual Lecture-Tutorials for Introductory Astronomy.
Sound Wave Propagation from Underdamped Free Oscillation of Metallic Cantilever Beams
Authors: Tarigan Hendra Jaya
Published: December 2021

We describe here a low-cost experiment for introductory physics students where they compare the physical properties of aluminum and steel by means of cantilever oscillations. This, in turn, allows the students to improve their physical intuition about these materials. Further, the students can apply their physics and mathematics knowledge and skills to create an experiment-based physical model.
Slamming a door
Authors: Greenslade Thomas B.
Published: December 2021

My father, an expert science teacher, was a firm believer in the Socratic method. Here the student is assumed to know the answers, and the task of the instructor is to bring forth this information and then help the student organize it.
Using Math in Physics: 5. Functional dependence
Authors: Redish Edward
Published: December 2021

When students are learning to use math in physics, one of the most important ideas they need to learn is that equations are not just calculational tools; they represent relationships between physical variables that change together (co-vary). How much a change in one variable or parameter is associated with a change in another depends on how they appear in the equation—their functional dependence. Understanding this sort of relationship is rarely emphasized in introductory mathematics classes, and students who have not yet learned to blend conceptual ideas with mathematical symbols may not see the relevance and power of this idea. We need to explicitly teach functional dependence as part of our effort to help students learn to use math productively in science.
Sequential Submaximal Training in Elite Male Rowers Does Not Result in Amplified Increases in Interleukin-6 or Hepcidin
Authors: Fensham Nikita C. , McKay Alannah K.A. , Tee Nicolin , Lundy Bronwen , Anderson Bryce , Morabito Aimee , Ross Megan L.R. , Burke Louise M.
Published: December 2021

Previous research investigating single bouts of exercise have identified baseline iron status and circulating concentrations of interleukin-6 (IL-6) as contributors to the magnitude of postexercise hepcidin increase. The current study examined the effects of repeated training bouts in close succession on IL-6 and hepcidin responses. In a randomized, crossover design, 16 elite male rowers completed two trials, a week apart, with either high (1,000 mg) or low (<50 mg) calcium pre-exercise meals. Each trial involved two, submaximal 90-min rowing ergometer sessions, 2.5 hr apart, with venous blood sampled at baseline; pre-exercise; and 0, 1, 2, and 3 hr after each session. Peak elevations in IL-6 (approximately 7.5-fold, p < .0001) and hepcidin (approximately threefold, p < .0001) concentrations relative to baseline were seen at 2 and 3 hr after the first session, respectively. Following the second session, concentrations of both IL-6 and hepcidin remained elevated above baseline, exhibiting a plateau rather than an additive increase (2 hr post first session vs. 2 hr post second session, p = 1.00). Pre-exercise calcium resulted in a slightly greater elevation in hepcidin across all time points compared with control (p = .0005); however, no effect on IL-6 was evident (p = .27). Performing multiple submaximal training sessions in close succession with adequate nutritional support does not result in an amplified increase in IL-6 or hepcidin concentrations following the second session in male elite rowers. Although effects of calcium intake require further investigation, athletes should continue to prioritize iron consumption around morning exercise prior to exercise-induced hepcidin elevations to maximize absorption.
Management of Patellar Tendinopathy Through Monitoring, Load Control, and Therapeutic Exercise: A Systematic Review
Authors: Núñez-Martínez Pablo , Hernández-Guillen David
Published: December 2021

Context: Patellar tendinopathy presents with persistent tendon pain located in the lower pole of the patella and loss of function related to mechanical load. Although its pathogenesis is not completely clear, conservative treatment including exercise is the main intervention of patellar tendinopathy treatment. Objective: To describe the efficacy of patellar tendinopathy management through therapeutic exercise, and control and monitoring of loads. Evidence Acquisition: MEDLINE, WoS, Cochrane Plus, PEDro, and the gray literature were searched from inception to July 2021. Based on the PICO strategy, the inclusion criteria were clinical trials published in English or Spanish; outcomes of function, pain, and strength; patients with patellar tendinopathy with no age or gender limitations; using an active intervention; and at least a methodological quality equal to or greater than 3 points on the Jadad scale. All data were analyzed by 2 independent reviewers (P.N.-M. and D.H.-G.). Studies were qualitatively synthesized using a descriptive synthesis. The methodological quality and risk of bias assessment were performed with the PEDro and Jadad scale, respectively. Evidence Synthesis: A total of 136 articles were identified, of which 12 met the eligibility criteria. All of them were regarded as presenting a moderate risk of bias and their methodological quality was considered acceptable to good. Recovering patellar tendinopathy with therapeutic exercise seems to significantly improve function, pain, and strength after intervention and even lasted over time. Conclusion: A treatment based on load monitoring and physical exercise has proven to be effective in rehabilitating patellar tendinopathy, with positive results in the short and medium term.
Female Testosterone: Contested Terrain
Authors: Krane Vikki , Calow Emma , Panunti Brandy
Published: December 2021

World Athletics policy narrowly defines female athletes, creating contested bodies in elite sport. Framed by feminist cultural studies and transfeminism, we discuss the eligibility rules and their real-life impact. Women with naturally elevated endogenous testosterone (hyperandrogenism) are being treated as if they are cheating. That high testosterone in female bodies has been deemed an unfair competitive advantage is consistent with dominant cultural narratives rather than the research about testosterone and sport performance. Applying an intersectional lens, it becomes clear that race, region, class, and nation intersect so that women athletes from the Global South are disproportionately affected by the eligibility regulations. This creation of contested bodies has led to critical mental and physical health outcomes. Cherry-picking one biological component of a body as the cause of exceptional performance in elite sport is irresponsible. Instead, we need education, compassion, and to follow sound science grounded in moral and ethical research.
Cell-by-cell dissection of phloem development links a maturation gradient to cell specialization
Authors: Roszak Pawel , Heo Jung-ok , Blob Bernhard , Toyokura Koichi , Sugiyama Yuki , de Luis Balaguer Maria Angels , Lau Winnie W. Y. , Hamey Fiona , Cirrone Jacopo , Madej Ewelina , Bouatta Alida M. , Wang Xin , Guichard Marjorie , Ursache Robertas , Tavares Hugo , Verstaen Kevin , Wendrich Jos , Melnyk Charles W. , Oda Yoshihisa , Shasha Dennis , Ahnert Sebastian E. , Saeys Yvan , De Rybel Bert , Heidstra Renze , Scheres Ben , Grossmann Guido , Mähönen Ari Pekka , Denninger Philipp , Göttgens Berthold , Sozzani Rosangela , Birnbaum Kenneth D. , Helariutta Yrjö
Published: December 2021

Root meristem controls

The plant meristem, a small cluster of stem cells generates all of the cell types necessary for the plant’s indeterminate growth pattern. Roszak
et al
. use single-cell analyses to follow development from the stem cell to the enucleated cell of the phloem vasculature. In the root of the small mustard plant
Arabidopsis
, this process takes just over 3 days, and the developmental trajectory spans more than a dozen different cell states. A transcriptional program initially held under repressive control is released as those initial repressors dissipate. Reciprocal repression by regulators early and late in the developmental trajectory control a rapid switch in the differentiation program. —PJH
Early giant reveals faster evolution of large body size in ichthyosaurs than in cetaceans
Authors: Sander P. Martin , Griebeler Eva Maria , Klein Nicole , Juarbe Jorge Velez , Wintrich Tanja , Revell Liam J. , Schmitz Lars
Published: December 2021

Early marine giant

The largest animals to have ever lived occupied the marine environment. Modern cetaceans evolved their large size over tens of millions of years in response to the increased productivity of cold marine waters. However, whales were not the first marine giants to evolve. Sanderet al. describe a 244-million-year-old fossil ichthyosaur that would have rivaled modern cetaceans in size (see the Perspective by Delsett and Pyenson). The animal existed at most 8 million years after the emergence of the first ichthyosaurs, suggesting a much more rapid size expansion that may have been fueled by processes after the Permian mass extinction. —SNV
Semiconductor nanochannels in metallic carbon nanotubes by thermomechanical chirality alteration
Authors: Tang Dai-Ming , Erohin Sergey V. , Kvashnin Dmitry G. , Demin Victor A. , Cretu Ovidiu , Jiang Song , Zhang Lili , Hou Peng-Xiang , Chen Guohai , Futaba Don N. , Zheng Yongjia , Xiang Rong , Zhou Xin , Hsia Feng-Chun , Kawamoto Naoyuki , Mitome Masanori , Nemoto Yoshihiro , Uesugi Fumihiko , Takeguchi Masaki , Maruyama Shigeo , Cheng Hui-Ming , Bando Yoshio , Liu Chang , Sorokin Pavel B. , Golberg Dmitri
Published: December 2021

Straining to make a transistor

The use of carbon nanotubes (CNTs) as short-channel-length transistors will require control of their chirality, which determines whether they are semiconducting or metallic and if they form strong, low-resistance contacts. Tang
et al
. fabricated CNT intramolecular transistors by progressive heating and straining of individual CNTs within a transmission electron microscope. Changes to chirality along sections of the nanotube created metallic-to-semiconducting transitions. A semiconducting nanotube channel was covalently bonded to the metallic nanotube source and drain regions. The resulting CNT intramolecular transistors had channel lengths as short as 2.8 nanometers. —PDS
Pol IV and RDR2: A two-RNA-polymerase machine that produces double-stranded RNA
Authors: Huang Kun , Wu Xiao-Xian , Fang Cheng-Li , Xu Zhou-Geng , Zhang Hong-Wei , Gao Jian , Zhou Chuan-Miao , You Lin-Lin , Gu Zhan-Xi , Mu Wen-Hui , Feng Yu , Wang Jia-Wei , Zhang Yu
Published: December 2021

A tunnel between RNA polymerases

Eukaryotes encode five multiple-subunit, DNA-dependent RNA polymerases, of which Pol I, Pol II, and Pol III function as single units to produce cellular single-stranded RNA. The plant-specific Pol IV forms a complex with RDR2 (an RNA-dependent RNA polymerase) to produce double-stranded precursors of small interfering RNA essential for genomic DNA methylation. Huang
et al
. determined the cryo–electron microscopy structures of the Pol IV-RDR2 complex. The structures show that Pol IV and RDR2 connect their active centers through an inner RNA transfer channel and that Pol IV reverses transcription direction and hands over its transcript directly through the channel to RDR2 for the production of the second strand of the double-stranded RNA. —DJ
Magnetic control in the terahertz
Authors: Juraschek Dominik M. , Narang Prineha
Published: December 2021

Strong magnon-phonon coupling may help develop superfast optical drives
Teaching natural enzymes new radical tricks
Authors: Zhang Yang , Dydio Paweł
Published: December 2021

Cytochromes P450 were engineered to conduct abiotic, stereoselective radical reactions