Strong Barriers Research Articles

Primary glia cells from bank vole propagate multiple rodent-adapted scrapie prions

Since the beginning prion research has been largely dependent on animal models for deciphering the disease, drug development or prion detection and quantification. Thereby, ethical as well as cost and labour-saving aspects call for alternatives in vitro. Cell models can replace or at least complement animal studies, but their number is still limited and the application usually restricted to certain strains and host species due to often strong transmission barriers. Bank voles promise to be an exception as they or materials prepared from them are uniquely susceptible to prions from various species in vivo, in vitro and in cell-free applications. Here we present a mainly astrocyte-based primary glia cell assay from bank vole, which is infectible with scrapie strains from bank vole, mouse and hamster. Stable propagation of bank vole-adapted RML, murine 22L and RML, and hamster 263K scrapie is detectable from 20 or 30 days post exposure onwards. Thereby, the infected bank vole glia cells show similar or even faster prion propagation than likewise infected glia cells of the corresponding murine or hamster hosts. We propose that our bank vole glia cell assay could be a versatile tool for studying and comparing multiple prion strains with different species backgrounds combined in one cell assay.

Digitization in the Design and Construction Industry—Remote Work in the Context of Sustainability: A Study from Poland

The article presents the results of research on the digitization of services provided by the design industry in the context of the implementation of sustainable development goals, especially environmental sustainability. First, a literature review has been done. These research goals were established in the publication: investigating the impact of remote work on the implementation of sustainable development goals (in particular, environmental), examining the essence of better perception of remote work and digitization of the design process by employees of the design and construction industry, and examining barriers and factors favoring the digitization of the design and construction industry in Poland. Both a survey and interviews were carried out. To analyze data obtained from the interviews, the Colaizzi’s methodology was performed. The data obtained as a result of the survey were subjected to a statistical analysis using a cluster analysis (Ward’s method). Groups (clusters) of strong and weak barriers, supporting factors, and sustainability factors were defined. The COVID-19 pandemic has perpetuated the digitization trend in this industry. Employees and owners of project offices prefer remote work due to the flexibility of working time, time savings, work comfort, safety, and savings. Industry employees recognize the advantages and benefits of remote work in terms of environmental sustainability. The environmental impact in the form in the reduction of electricity consumption by large office buildings and reduction of the emission of harmful substances contained in car exhaust fumes are the most frequently mentioned environmental advantages. The biggest barriers are legal aspects, and sometimes difficult cooperation with a client. The research results presented in this publication, as well as the methodology adopted, are a contribution to the literature on the perception and comfort of remote work, the social effects of the COVID-19 pandemic, and environmental sustainability.

To Prescribe or Not to Prescribe?: Barriers and Motivators for Progressing Along Each Stage of the Buprenorphine Training and Prescribing Path.

This study aimed to identify the strongest barriers and motivators associated with each step toward buprenorphine prescribing (1. obtaining a waiver, 2. beginning to prescribe, and 3. prescribing to more people) among a sample of Missouri-based medical professionals (N = 130). Item weights (number of endorsements times mean rank of the item's importance) were calculated based on their responses. Across groups, lack of access to psychosocial support services, need for higher levels of care, and clinical complexity were strong barriers. Among non-prescribers (n = 57, 46.3%), administrative burden, potential of becoming an addiction clinic, and concern about misuse and diversion were most heavily weighted. Among prescribers (n = 66, 53.7%), patients' inability to afford medications was a barrier across phases. Prominent motivators among all groups were the effectiveness of buprenorphine, improvement in other health outcomes, and a personal interest in treating addiction. Only prescribers reported the presence of institutional support and mentors as significant motivators.

MOUNTAIN LIONS (PUMA CONCOLOR) RESIST LONG-TERM DIETARY EXPOSURE TO CHRONIC WASTING DISEASE.

For nearly 18 yr, we evaluated susceptibility of captive mountain lions (Puma concolor) to chronic wasting disease (CWD) in the face of repeated exposure associated with consuming infected cervid carcasses. Three mountain lions with a monomorphic prion protein gene (PRNP) sequence identical to that described previously for the species had access to parts of ≥432 infected carcasses during ≥2,013 feeding occasions, conservatively representing >14,000 kg of infected feed material, during May 2002 to March 2020. The proportion of diet in infected carcass material averaged 43% overall but differed from year to year (minimally 11-74%). Most infected carcasses were mule deer (Odocoileus hemionus; ∼75%). We observed no clinical signs suggestive of progressive encephalopathy or other neurologic disease over the ∼14.5-17.9 yr between first known exposure and eventual death. Histopathology revealed no spongiform changes or immunostaining suggestive of prion infection in multiple sections of nervous and lymphoid tissue. Similarly, none of 133 free-ranging mountain lion carcasses sampled opportunistically during 2004-20 showed immunostaining consistent with prion infection in sections of brainstem or lymph node. These findings align with prior work suggesting that CWD-associated prions face strong barriers to natural transmission among species outside the family Cervidae.

A Planar Culture Model of Human Absorptive Enterocytes Reveals Metformin Increases Fatty Acid Oxidation and Export.

Background & AimsFatty acid oxidation by absorptive enterocytes has been linked to the pathophysiology of type 2 diabetes, obesity, and dyslipidemia. Caco-2 and organoids have been used to study dietary lipid-handling processes including fatty acid oxidation, but are limited in physiological relevance or preclude simultaneous apical and basal access. Here, we developed a high-throughput planar human absorptive enterocyte monolayer system for investigating lipid handling, and then evaluated the role of fatty acid oxidation in fatty acid export, using etomoxir, C75, and the antidiabetic drug metformin.MethodsSingle-cell RNA-sequencing, transcriptomics, and lineage trajectory was performed on primary human jejunum. In vivo absorptive enterocyte maturational states informed conditions used to differentiate human intestinal stem cells (ISCs) that mimic in vivo absorptive enterocyte maturation. The system was scaled for high-throughput drug screening. Fatty acid oxidation was modulated pharmacologically and BODIPY (Thermo Fisher Scientific, Waltham, MA) (B)–labeled fatty acids were used to evaluate fatty acid handling via fluorescence and thin-layer chromatography.ResultsSingle-cell RNA-sequencing shows increasing expression of lipid-handling genes as absorptive enterocytes mature. Culture conditions promote ISC differentiation into confluent absorptive enterocyte monolayers. Fatty acid-handling gene expression mimics in vivo maturational states. The fatty acid oxidation inhibitor etomoxir decreased apical-to-basolateral export of medium-chain B-C12 and long-chain B-C16 fatty acids, whereas the CPT1 agonist C75 and the antidiabetic drug metformin increased apical-to-basolateral export. Short-chain B-C5 was unaffected by fatty acid oxidation inhibition and diffused through absorptive enterocytes.ConclusionsPrimary human ISCs in culture undergo programmed maturation. Absorptive enterocyte monolayers show in vivo maturational states and lipid-handling gene expression profiles. Absorptive enterocytes create strong epithelial barriers in 96-Transwell format. Fatty acid export is proportional to fatty acid oxidation. Metformin enhances fatty acid oxidation and increases basolateral fatty acid export, supporting an intestine-specific role.

Re-Imagining the Data Collection and Analysis Research Process by Proposing a Rapid Qualitative Data Collection and Analytic Roadmap Applied to the Dynamic Context of Precision Medicine

Our implementation science study focuses on implementing a new way of practice and offers methodological specificity about how to rapidly investigate an individually tailored precision medicine intervention. A qualitative study advancing a new methodology for speedily identifying barriers and enablers to implementation in the context of childhood cancer. Data were collected through rapid ethnography, coded using the Consolidated Framework for Implementation Research, and analysed by Sentiment Analysis. Thirty-eight data collection events occurred during 14 multidisciplinary tumour board meetings, 14 curation meetings, and 10 informal conversations. Sentiment Analysis distilled Consolidated Framework for Implementation Research codes to reveal key barriers and enablers to implementation. A traffic light labelling system has been used to present levels of positivity and negativity (green for strong enablers and red for strong barriers), highlighting levels of concern regarding implementation. Within the intervention design characteristics, “Adaptability” was the strongest enabler and “Design quality and safety” the strongest barrier. Among the contextual factors: “Networks and communication” were the strongest enabler, and “Available resources” were the strongest barrier. Overall, there was a higher percentage of negative sentiment towards intervention design characteristics and contextual factors than positive sentiment, while more concerns were raised about intervention design factors than contextual factors. This study offers a rapid qualitative data collection and analytic methodological roadmap for establishing barriers and enablers to a paediatric precision medicine intervention.

Genetic diversity and population structure for ocelots (Leopardus pardalis) in Costa Rica

Abstract Ocelots (Leopardus pardalis) are a wide-ranging felid species, occurring from southern United States to northern Argentina. They occupy various habitats and are usually considered the most abundant wild cat species in the Neotropics. However, genetic studies that include free-ranging Mesoamerican ocelots are rare and generally based on small sample sizes. This is the first conservation genetics study on ocelots in Costa Rica and the second one in Mesoamerica that has conducted a genetic assessment of the species at a countrywide scale. We evaluated genetic diversity and population structure of ocelots using 15 microsatellite loci in 28 successfully genotyped individuals from throughout the country. We also compared genetic diversity of Costa Rican ocelots with that of jaguars (Panthera onca) and pumas (Puma concolor) in the country, and with ocelots in Belize. Genetic diversity of ocelots in Costa Rica was relatively high as measured by rarified allelic richness (AR = 5.50 ± 1.36) and expected heterozygosities (HE = 0.79 ± 0.08). We did not detect patterns of genetic substructure, suggesting high levels of gene flow throughout the country and no strong barriers to movement. As expected, genetic diversity of Costa Rican ocelots was higher than co-occurring jaguars and pumas. Additionally, levels of genetic diversity were slightly higher in Costa Rican ocelots when compared with their counterparts in Belize, confirming the south to north decrease in genetic diversity reported in other studies. Our study provides critical baseline information to understand the status of wild ocelot populations in Costa Rica. Future studies on ocelots and other threatened or keystone species should also integrate genetic monitoring and conservation genetics analysis to properly inform management decisions, guarantee their long-term survival, and improve the resilience of ecosystems.

Cognitive disabilities and web accessibility: a survey into the Brazilian web development community

Cognitive disabilities include a diversity of conditions related to cognitive functions, such as reading, understanding, learning, solving problems, memorization and speaking. They differ largely from each other, making them a heterogeneous complex set of disabilities. Although the awareness about cognitive disabilities has been increasing in the last few years, it is still less than necessary compared to other disabilities. The need for an investigation about this issue is part of the agenda of the Challenge 2 (Accessibility and Digital Inclusion) from GranDIHC-Br. This paper describes the results of an online exploratory survey conducted with 105 web development professionals from different sectors to understand their knowledge and barriers regarding accessibility for people with cognitive disabilities. The results evidenced three biases that potentially prevent those professionals from approaching cogni-tive disabilities: strong organizational barriers; difficulty to understand user needs related to cognitive disabilities; a knowledge gap about web accessibility principles and guidelines. Our results confirmed that web development professionals are unaware about cognitive disabilities mostly by a lack of knowledge about them, even if they understand web accessibility in a technical level. Therefore, we suggest that applied research studies focus on how to fill this knowledge gap before providing tools, artifacts or frameworks.

Transgender Kathoey and gay men using tourist-zone scenes as ‘social opportunities’ for nonheteronormative living in Thailand

This article studies life-trajectories of a specific generation of Kathoey and gay men, born into rural poverty in Northeastern Isaan 30–50 years ago, based on biographical accounts. Subjects are male-to-female transgender Kathoey and cisgendered (masculine-identified or gender-normative) gay men. A ‘sustainable nonheteronormative life’ is one providing sufficient resources of recognition for validating gender identity (Kathoey) or sexuality (gay men), and wealth to be economically viable. How did they strive to make spaces for nonheteronormative living when confronted by ‘blocked’ social opportunities of double discrimination based on transphobia (Kathoey) and homophobia (gay men), and class/status? The research unpacks which strong barriers of discrimination confronted them at distinct life-stages, and their agency and strategies to challenge these. Family, work and place are investigated as core social factors influentially defining a person’s positioning and life-chances, while shaping their pathway through social space over time. The empirical study reconstructs subjects’ lived experiences in distinct life-stages: village childhood; early postmigration city experiences; building lives in tourist-zone scenes; and reaching back ‘home’. The main finding is that tourist-zone scenes present new social opportunities that enable a few to transform their social and geographical displacement away from mainstream heteronormative society into an asset and achieve ‘success’. Tourist-zones transgress dominant (hetero)norms and values, but provide social infrastructures, communities and countercultural norms that support specific forms of nonheteronormative living, albeit dependent on foreign men. By migrating to tourist-zones, subjects stepped out of mainstream society, but over time drew on resources to build new social pathways towards living nonheteronormatively.

Dead-End Hybridization in Walnut Trees Revealed by Large-Scale Genomic Sequence Data.

Although hybridization plays a large role in speciation, some unknown fraction of hybrid individuals never reproduces, instead remaining as genetic dead-ends. We investigated a morphologically distinct and culturally important Chinese walnut, Juglans hopeiensis, suspected to have arisen from hybridization of Persian walnut (J. regia) with Asian butternuts (J. cathayensis, J. mandshurica, and hybrids between J. cathayensis and J. mandshurica). Based on 151 whole-genome sequences of the relevant taxa, we discovered that all J. hopeiensis individuals are first-generation hybrids, with the time for the onset of gene flow estimated as 370,000 years, implying both strong postzygotic barriers and the presence of J. regia in China by that time. Six inversion regions enriched for genes associated with pollen germination and pollen tube growth may be involved in the postzygotic barriers that prevent sexual reproduction in the hybrids. Despite its long-recurrent origination and distinct traits, J. hopeiensis does not appear on the way to speciation.

Barriers to getting into postgraduate specialty training for junior Australian doctors: An interview-based study.

Medical training is a long process that is not complete until doctors finish specialty training. Getting into specialty training is challenging because of strong competition for limited places, depending on doctors' chosen field. This may have a negative impact on doctor well-being and reduce the efficiency of the medical training system. This study explored the barriers of pre-registrar (junior) doctors getting into specialty training programs to inform tailored support and re-design of speciality entry systems. From March to October 2019, we conducted 32 semi-structured interviews with early-career doctors in Australia, who had chosen their specialty field, and were either seeking entry, currently undertaking or had recently completed various fields of specialty training. We sought reflections about barriers and major influences to getting into specialty training. In comparing and contrasting generated themes, different patterns emerged from doctors targeting traditionally non-competitive specialty fields like General Practice (GP) and other specialties (typically more competitive fields). As a result we explored the data in this dichotomy. Doctors targeting entry to GP specialties had relatively seamless training entry and few specific barriers. In contrast, those pursuing other specialties, regardless of which ones, relayed multiple barriers of: Navigating an unpredictable and complex system with informal support/guidance; Connecting to the right people/networks for relevant experience; Pro-actively planning and differentiating skills with recurrent failure of applications. Our exploratory study suggests that doctors wanting to get into non-GP specialty training may experience strong barriers, potentially over multiple years, with the capacity to threaten their morale and resilience. These could be addressed by a clearinghouse of information about different speciality programs, broader selection criteria, feedback on applications and more formal guidance and professional supports. The absence of challenges identified for doctors seeking entry to GP could be used to promote increased uptake of GP careers.

Natural interploidy hybridization among the key taxa involved in the origin of horticultural chrysanthemums

AbstractUnderstanding hybridization and introgression between natural plant populations can give important insights into the origins of cultivated species. Recent studies suggest differences in ploidy might not create such strong reproductive barriers as once thought, and thus studies into cultivated origins should examine all co‐occurring taxa, including those with contrasting ploidy levels. Here, we characterized hybridization between Chrysanthemum indicum L., Chrysanthemum vestitum (Hemsley) Ling and Chrysanthemum vestitum var. latifolium (Zhou & Chen), the most important wild species involved in the origins of cultivated chrysanthemums. We analyzed the population structure of 317 Chrysanthemum accessions based on 13 microsatellite markers and sequenced chloroplast trnL‐trnF for a subset of 103 Chrysanthemum accessions. We identified three distinct genetic clusters, corresponding to the three taxa. We detected 20 hybrids between species of different ploidy levels, of which 19 were between C. indicum (4x) and C. vestitum (6x) and one was between C. indicum and C. vestitum var. latifolium (6x). Fourteen hybrids between C. indicum and C. vestitum were from one of the five study sites. Chrysanthemum vestitum and C. vestitum var. latifolium share only one chloroplast haplotype. The substantially different number of hybrids between hybridizing species was likely due to different levels of reproductive isolation coupled with environmental selection against hybrids. In addition, human activities could play a role in the different patterns of hybridization among populations.

Training prevalence, knowledge and attitudes towards cardiopulmonary resuscitation: a survey amongst 5,921 preschool and school teachers

Abstract Purpose Preschool and school teachers could play an important role both in training children in cardiopulmonary resuscitation (CPR) and in providing necessary help in case of witnessing an emergency. This study aimed to investigate prevalence of CPR training, CPR knowledge, attitudes and willingness to perform CPR among preschool and school teachers in the territory of the Republic of Crimea, in the northern Black Sea region. Methods An anonymous online questionnaire survey was conducted in February–March 2021 utilizing Google Forms. In particular, the participants were asked to rate their knowledge of CPR and willingness to perform CPR (on a stranger, a pupil or a loved one) on a 5-point scale, and to indicate recommended chest compression rate and hand position for compressions. Results Out of 5,921 surveyed teachers, 3,765 (64%) reported previous CPR training. Among the trained, 55% attended training more than one year ago, 44% completed a CPR training course once. Reasons for not being trained were most commonly reported as “never thought about the need to go for training” (42%), “nobody demanded me to get trained” (38%) or “did not know where to attend the training” (21%). Self-perceived knowledge of CPR was rated as follows: very good – 0.4%, good – 7.8%, moderate – 37.8%, poor – 44.6%, absent – 9.4%. Hand position for giving chest compressions was indicated correctly by 66% participants, compression rate – by 16% respondents. Correct answering to the questions and higher self-perceived knowledge were associated with previous CPR training (p<0.001). 54% reported they wish to get trained in CPR. 28% confirmed readiness to teach CPR as part of their extracurricular work (provided that they will get preliminary training, and upon availability of proper training supplies and instructional program). Proportion of respondents who expressed high willingness to attempt CPR (4–5 points) on a stranger, a pupil or a loved one amounted to 35%, 41% and 64%, respectively, mean level or readiness to perform CPR – 3.0, 3.1 and 3.8 points, respectively. Willingness to perform CPR was positively associated with previous CPR training and level of CPR knowledge (p<0.001). Fear to cause harm to a victim and lack of CPR knowledge and skills were most commonly reported as the strongest barriers to attempt CPR (reported by 49–51% and 31–36% respondents, respectively, depending on the type of supposed victim). Conclusions Coverage of the preschool and school teachers with recent CPR training is limited, levels of knowledge and self-confidence in CPR are generally low. Lack of competence impede readiness of the teachers to attempt CPR. There is a demand in enhancing involvement of teachers in CPR training and retraining in the Republic of Crimea. Most teachers want to get trained in CPR, and almost one third agree to teach CPR themselves, suggesting a reasonable way to improve availability of CPR training for both teachers and pupils. Funding Acknowledgement Type of funding sources: None.

Older Adults’ Views and Attitudes on Physical Activity; Reasons to Participate and Abstain

ABSTRACT Purpose: Despite numerous established benefits of exercise, many older adults do not get enough. The purpose of this study was to identify facilitators and barriers to physical activity/exercise; gain greater understanding of older adults’physical activity self-efficacy; and increase understanding of how to reduce sedentary behavior.Design: Cross-sectional descriptiveMethods: Quantitative with convenience sample of 66 older adultsFindings: Nearly one third of participants reported engaging in regular physical activity. They tended to have rather strong physical activity self-efficacy and limited barriers to being active.Conclusions: The sample had limited involvement in physical activity or exercise, despite feeling confident in their ability to be active. There could be additional barriers or motivating factors that are preventing them from being more active.Clinical Evidence: Honest and directed conversation about older adults’ understanding and attitudes towards exercise, paired with an individualized plan tailored to their interests and lifestyle could help increase physical activity/exercise.

Perceived facilitators of and barriers to mental health treatment engagement among decision-making competent adolescents in Greece

BackgroundA subset of adolescents with mental disorders are likely to have decision-making capacity that facilitates their therapy engagement. However, there are high rates of drop-out in mental health settings.AimThis study aims to identify perceived barriers to or facilitators of mental health care engagement among adolescents with decision-making competence in Greece.MethodsA qualitative study was conducted using semi-structured interviews of adolescents with a wide range of mental health problems. In addition, two psychometric assessment measures were used to define who to include or exclude from the study sample.ResultsPositive attitudes and experiences with therapy were reported as strong (“major”) facilitators of therapy engagement for adolescents with mental disorders, whereas negative experiences with therapy were reported as strong barriers to it. Furthermore, and most importantly, a “good” adolescent-therapist relationship was reported as a strong facilitator, whereas negative experiences of participants with their therapist were reported as strong barriers. Moreover, goals such as getting rid of symptoms, improving personal well-being, and improving social skills and relationships (especially with peers) emerged as strong facilitators of therapy engagement. Importantly, the early remission of symptoms emerged from the study as a strong barrier to therapy engagement for participants. Among the weaker (“minor”) perceived facilitators were goals such as confessing to a trustworthy person, becoming able to achieve personal expectations and life goals, enhancing independence and self-esteem, and developing a positive self-image. The (active or supportive) role of family emerged as a facilitator. The stigma related to mental health emerged as both a (“minor”) facilitator of and barrier to therapy engagement for participants. Friends were reported as having a role ranging from neutral to mildly supportive.ConclusionA number of more or less strong barriers and facilitators were identified that, for the most part, were consistent with prior literature. However, the authors identified some nuances that are of clinical importance. For instance, adolescents are most likely to terminate the treatment prematurely if they experience early symptom remission. Highlighting the role of therapy in achieving their goals or improving their families’ well-being might be used by therapists to reduce the attrition rate.

Seismic and Aseismic Cycle of the Ecuador–Colombia Subduction Zone

The Colombia–Ecuador subduction zone is an exceptional natural laboratory to study the seismic cycle associated with large and great subduction earthquakes. Since the great 1906 Mw = 8.6 Colombia–Ecuador earthquake, four large Mw > 7.5 megathrust earthquakes occurred within the 1906 rupture area, releasing altogether a cumulative seismic moment of ∼35% of the 1906 seismic moment. We take advantage of newly released seismic catalogs and global positioning system (GPS) data at the scale of the Colombia–Ecuador subduction zone to balance the moment deficit that is building up on the megathrust interface during the interseismic period with the seismic and aseismic moments released by transient slip episodes. Assuming a steady-state interseismic loading, we found that the seismic moment released by the 2016 Mw = 7.8 Pedernales earthquake is about half of the moment deficit buildup since 1942, suggesting that the Pedernales segment was mature to host that seismic event and its postseismic afterslip. In the aftermath of the 2016 event, the asperities that broke in 1958 and 1979 both appears to be mature to host a large Mw > 7.5 earthquakes if they break in two individual seismic events, or an Mw∼7.8–8.0 earthquake if they break simultaneously. The analysis of our interseismic-coupling map suggests that the great 1906 Colombia–Ecuador earthquake could have ruptured a segment of 400 km-long bounded by two 80 km wide creeping segments that coincide with the entrance into the subduction of the Carnegie ridge in Ecuador and the Yaquina Graben in Colombia. These creeping segments share similar frictional properties and may both behave as strong seismic barriers able to stop ruptures associated with great events like in 1906. Smaller creeping segments are imaged within the 1906 rupture area and are located at the extremities of the large 1942, 1958, 1979, and 2016 seismic ruptures. Finally, assuming that the frequency–magnitude distribution of megathrust seismicity follows the Gutenberg–Richter law and considering that 50% of the transient slip on the megathrust is aseismic, we found that the maximum magnitude subduction earthquake that can affect this subduction zone has a moment magnitude equivalent to Mw ∼8.8 with a recurrence time of 1,400 years. No similar magnitude event has yet been observed in that region.

Recent results of fusion triple product on EAST tokamak

High fusion triple product has been obtained in the advanced scenarios with high normalized beta (β N) on the Experimental Advanced Superconducting Tokamak (EAST). A record value of n i0 T i0 τ E ∼ 1.0 × 1019 m−3 keV s for EAST deuterium plasma has been achieved, which is due to the formation of strong and broad internal transport barriers (ITBs) in n e, T e and T i profiles. Analysis shows that the strong ITB formation could be attributed to the reduction of transport from ITG modes. Based on the analysis, the physical mechanisms and methods to further improve the plasma performance are discussed.

Effect of grain refinement and twin structure on the strength and ductility of Inconel 625 alloy

The yield strength levels of solid-solution strengthened nickel-based superalloys are low compared to precipitation-strengthened counterparts. Here, Inconel 625 alloy was used as a model, thermo-mechanical treatments were employed to improve the yield strength of the alloys. Compared to the as-solution condition, the yield strength was increased from 291 to 676 MPa with the ductility reduced from 75 to 50% after cold rolling and annealing at 1073 K for 30 min. The strength-ductility synergy originates from (1) grain boundaries and pre-existing annealing twins act as strong barriers to hinder dislocations motion, and (2) the formation of deformation twins during plastic deformation provides an extra work-hardening region to maintain the excellent ductility. The strengthening effect of annealing twins is determined by the thickness rather than the length fraction. Deformation twins tend to form in the fine-grained Inconel 625 alloy (the grain size ranging from 3.1 to 4.7 μm) during plastic deformation. This is the reason for an extra work hardening region in the hardening curve. Our present work can provide a reference for realizing the strength-ductility synergy of solid-solution strengthened nickel-based superalloys.

Transcultural Impact of Learning to Teach Sport Education on Preservice Teachers’ Perceived Teaching Competence, Autonomy, and Academic Motivation

Purpose: To compare the impact of the experience of learning to teach sport education on preservice teachers’ (from Spain, Chile, and Mexico) perceived professional competence, autonomy, and academic motivation and to explore participants’ perceptions of their country’s sociocultural and curricular aspects that may influence sport education implementation. Method: Framed by the “pedagogy of dialogue” and a “living the curriculum” approach, three consecutive miniseasons on alternative invasion games were enacted (n = 30 lessons). A quasi-experimental pre- and posttest mixed-methods design was followed, with a total of 163 preservice teachers. The quantitative data on preservice teachers’ teaching competence, autonomy, and academic motivation were collected through three validated questionnaires. Focus group interviews and field notes were used to gather qualitative information. Results: The main quantitative analysis exposed no relevant differences among the transcultural sample of preservice teachers related to the analyzed variables. Qualitative analysis showed the power of contextual factors to filter preservice teachers’ understanding of the model. Conclusions: The dialogical nature of the approach and the miniseason structure allowed the preservice teachers to achieve a better understanding of the pedagogy of sport education and to optimize their motivation to use it in the future. The rigidity of the national curriculum and the custodial nature of school reality, however, present strong barriers to this end.

Allochrony of neighbour ecological species: Can isolation by time maintain divergence? The natural experiment of sympatric Nothofagus

Ecological mechanisms that maintain species identity between potentially interfertile sympatric populations are puzzling. Local adaptation to a particular environment by means of phenology may confine plants to very specific habitats that may result in assortative mating within an initially panmictic population. Nothofagus pumilio, N. antarctica and N. dombeyi are sister species. They can occur in sympatry and are known to interbreed but they are morphologically and ecologically different. We recorded leafing and flowering phenologies and their thermal requirements to reach each phenophase at distinct locations during three growing seasons (2016–2018). We compared data for sympatric and allopatric populations of different species, sites and elevations. Sympatric populations of different species have contrasting thermal requirements and thus uncoupled phenologies. Temperature, through differences in elevation, is the main driver of intraspecific phenological differences at the population level. Low elevation populations flower earlier than high elevation ones. Allopatric populations of each species are synchronic and reproductively linked to some degree. A combination of high ecological specialization and strong phenological pre-pollination barriers operate together to temporally isolate distinct species, against the homogenizing effect of the occasional or even persistent gene flow. The eventual hybrid formation could be negatively selected by strong local selection to contrasting environments.