bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of land cover type on community structure and functional traits of alpine stream benthic macroinvertebrates
Authors: Scotti Alberto , Füreder Leopold , Marsoner Thomas , Tappeiner Ulrike , Stawinoga Agnieszka E. , Bottarin Roberta
Published: December 2019

In the European Alps, due to the current changes in land use driven by different social and economic factors, grasslands and pastures are being increasingly replaced by forests. Whereas many studies have focused on the impacts of urbanisation and intensive agricultural activities, no study has evaluated the effects of changes among types of natural to semi‐natural land cover in the Alps with a focus on lotic environments.

Here, combining taxonomic and functional approaches, we show the effects of four different alpine land cover types (rocks, grasslands, coniferous forests, valley bottom pastures) on stream benthic macroinvertebrate communities. Irrespective of elevation, grasslands and pastures exhibited unpredicted similarity in terms of the composition of the macroinvertebrate assemblages and hosted the highest diversity of benthic organisms, whereas in each of the other land cover types, the density and diversity of the faunal assemblages showed distinct and characteristic values.

When analysing the functional diversity decomposed to richness, evenness, and divergence components, grasslands and pastures again showed a similar trend, being characterised by high levels of resource exploitation and niche differentiation, with the potential to host additional organisms. However, as expected, differences driven by land cover type and elevation emerged when examining the single functional traits, since elevation played a major role in terms of the distribution of traits conferring resistance and resilience.

Our results demonstrate that land cover type is a prominent factor influencing the taxonomic and functional variety of stream benthic macroinvertebrate communities. Moreover, alpine grasslands contained an unexpected diversity of aquatic insects, as previously assessed for other organisms (e.g. plants and snails). Overall, our study highlights the importance of the preservation of the diversity of habitats in the alpine region, with a special focus needed for valuable semi‐natural landscapes, such as grasslands and pastures, particularly in a time of increasing intensification and abandonment of lands in the alpine context.
Sea ice loss increases genetic isolation in a high Arctic ungulate metapopulation
Authors: Peeters Bart , Le Moullec Mathilde , Raeymaekers Joost A. M. , Marquez Jonatan F. , Røed Knut H. , Pedersen Åshild Ø. , Veiberg Vebjørn , Loe Leif Egil , Hansen Brage B.
Published: December 2019

Sea ice loss may have dramatic consequences for population connectivity, extinction–colonization dynamics, and even the persistence of Arctic species subject to climate change. This is of particular concern in face of additional anthropogenic stressors, such as overexploitation. In this study, we assess the population‐genetic implications of diminishing sea ice cover in the endemic, high Arctic Svalbard reindeer (Rangifer tarandus platyrhynchus) by analyzing the interactive effects of landscape barriers and reintroductions (following harvest‐induced extirpations) on their metapopulation genetic structure. We genotyped 411 wild reindeer from 25 sampling sites throughout the entire subspecies' range at 19 microsatellite loci. Bayesian clustering analysis showed a genetic structure composed of eight populations, of which two were admixed. Overall population genetic differentiation was high (mean FST = 0.21). Genetic diversity was low (allelic richness [AR] = 2.07–2.58; observed heterozygosity = 0.23–0.43) and declined toward the outer distribution range, where populations showed significant levels of inbreeding. Coalescent estimates of effective population sizes and migration rates revealed strong evolutionary source–sink dynamics with the central population as the main source. The population genetic structure was best explained by a landscape genetics model combining strong isolation by glaciers and open water, and high connectivity by dispersal across winter sea ice. However, the observed patterns of natural isolation were strongly modified by the signature of past harvest‐induced extirpations, subsequent reintroductions, and recent lack of sea ice. These results suggest that past and current anthropogenic drivers of metapopulation dynamics may have interactive effects on large‐scale ecological and evolutionary processes. Continued loss of sea ice as a dispersal corridor within and between island systems is expected to increase the genetic isolation of populations, and thus threaten the evolutionary potential and persistence of Arctic wildlife.
Spatio‐temporal pattern evolution and spatial spillover effect of green development efficiency: Evidence from Shandong Province, China
Authors: Guo Fuyou , Tong LianJun , Xu Limeng , Lu Xiao , Sheng Yanwen
Published: December 2019

Improving green development efficiency is urgently required, yet challenging, since it comprehensively reflects the bidirectional evolutionary relationship between regional development and resource and environmental consumption. The issue of regional green development efficiency has become a key topic; however, where the increase in efficiency originates and its spatial spillover effect remains unclear to date. Therefore, the spatial spillover effect of the green development efficiency of Shandong Province was quantified through the slack variable (SBM)‐Undesirable and Spatial Durbin model. The green development efficiency showed clear spatial differentiation in Shandong Province. This was more obvious than the polarized development trend of the provincial capital circle that has Jinan at its core and the eastern coastal region with Qingdao at its core. Green development efficiency has a significant spatial spillover effect. The regression coefficient of the direct effect of the economic development level is positive. The regression coefficient of the indirect effect of the marketization level and government financial support level is negative. Science and technology played a positive role in the promotion of the green development efficiency of local and neighboring cities. This study contributes empirical evidence to the green development efficiency associated with regional development and resource and environment consumption of Shandong Province.
Migration: A theoretical comparison on countries’ welfare
Authors: Gabszewicz Jean , Zanaj Skerdilajda
Published: December 2019

We compare the effects of migration on the production of public goods, on income taxes, and on the welfare of residents in the sending and receiving countries. Migration is driven by income differences between countries. Alternative wage adjustment scenarios are considered: fully flexible wages, upward rigidity, and unemployment. We show that in all scenarios, emigration is detrimental to welfare for the origin country. Migration improves welfare for the destination country in the presence of flexible wages and upward rigidity, but it has detrimental effects in the presence of unemployment.
Auctions with endogenous opting‐out fees and recursive winning procedures from the Talmud
Authors: Schwarz Mordechai E.
Published: December 2019

This article analyzes open ascending and first‐price sealed‐bid auctions with uncertain value, recursive winning procedure, and cooling‐off right in return for an endogenous opting‐out fee. I show that although equilibrium bidding strategies in these auctions tend to be less aggressive than in auctions with costless withdrawals, expected revenues are usually higher. Both auctions are spurious‐bidding free and the sealed‐bid auction is almost shill‐bidding robust.
Sequential formation of alliances in survival contests
Authors: Konishi Hideo , Pan Chen‐Yu
Published: December 2019

We consider asequential formationof alliances à la Bloch (1996) and Okada (1996), followed by a two‐stage contest in which alliances first compete with each other, and then the members in the winning alliance compete again for an indivisible prize. In contrast to Konishi and Pan (2019a), which adopted anopen‐membershipgame as the alliance formation process, alliances are allowed to limit their memberships (excludable alliances). We show that if members’ efforts are strongly complementary to each other, there will be exactly two asymmetric alliances: the larger alliance is formed first and then the remaining players form the smaller one. This result contrasts with the one under open membership, where moderate complementarity is necessary to support a two‐alliance structure. It is also in stark contrast with Bloch, Sánchez‐Pagés, and Soubeyran (2006), which shows that a grand coalition is formed in the same game if the prize is divisible and a binding contract can be used to avoid further conflicts after an alliance wins the prize.
Emotions, engagement, and self‐perceived achievement in a small private online course
Authors: Ding Yan , Zhao Ting
Published: December 2019

Emotions are critical to learning. However, the function of emotions in the emerging context of massive open online courses (MOOCs) has been under‐researched. The present study complemented this line of research by modelling the relation between learner emotions, engagement with videos, engagement with assignments, and self‐perceived achievement in a small private online course—a localized instance of an extended MOOC. The results suggested that whereas enjoyment, excitement, boredom, and annoyance were all significant predictors of video engagement, only excitement and annoyance were significant predictors of assignment engagement. Excitement, in particular, was the strongest or stronger predictor of both types of engagement. In addition, both types of engagement predicted self‐perceived achievement, but video engagement predicted self‐perceived achievement via the mediation of assignment engagement. Implications for designing more effective MOOCs were proposed.
PRMT5 promotes epithelial‐mesenchymal transition via EGFR‐β‐catenin axis in pancreatic cancer cells
Authors: Ge Lu , Wang Huizhi , Xu Xiao , Zhou Zhengrong , He Junbo , Peng Wanxin , Du Fengyi , Zhang Youli , Gong Aihua , Xu Min
Published: December 2019

Protein arginine methyltransferase 5 (PRMT5) has been implicated in the development and progression of human cancers. However, few studies reveal its role in epithelial‐mesenchymal transition (EMT) of pancreatic cancer cells. In this study, we find that PRMT5 is up‐regulated in pancreatic cancer, and promotes proliferation, migration and invasion in pancreatic cancer cells, and promotes tumorigenesis. Silencing PRMT5 induces epithelial marker E‐cadherin expression and down‐regulates expression of mesenchymal markers including Vimentin, collagen I and β‐catenin in PaTu8988 and SW1990 cells, whereas ectopic PRMT5 re‐expression partially reverses these changes, indicating that PRMT5 promotes EMT in pancreatic cancer. More importantly, we find that PRMT5 knockdown decreases the phosphorylation level of EGFR at Y1068 and Y1172 and its downstream p‐AKT and p‐GSK3β, and then results in down‐regulation of β‐catenin. Expectedly, ectopic PRMT5 re‐expression also reverses the above changes. It is suggested that PRMT5 promotes EMT probably via EGFR/AKT/β‐catenin pathway. Taken together, our study demonstrates that PRMT5 plays oncogenic roles in the growth of pancreatic cancer cell and provides a potential candidate for pancreatic cancer treatment.
Associations between conduct problems in childhood and adverse outcomes in emerging adulthood: a longitudinal Swedish nationwide twin cohort
Authors: Lichtenstein Paul , Cederlöf Martin , Lundström Sebastian , D'Onofrio Brian M. , Anckarsäter Henrik , Larsson Henrik , Pettersson Erik
Published: December 2019

Background

We examined whether childhood conduct problems predicted a wide range of adverse outcomes in emerging adulthood and whether the association with internalizing problems remained after adjusting for general comorbidity and externalizing problems.

Methods

Participants were 18,649 twins from the Child and Adolescent Twin Study in Sweden. At age 9/12, parents rated their children on eight conduct problems. Adverse outcomes were retrieved from national registers in emerging adulthood (median follow‐up time = 9.2 years), including diagnoses of six psychiatric disorders, prescriptions of antidepressants, suicide attempts, criminality, high school ineligibility, and social welfare recipiency. We estimated risk for the separate outcomes and examined if conduct problems predicted an internalizing factor above and beyond a general comorbidity and an externalizing factor. We used twin analyses to estimate genetic and environmental contributions to these associations.

Results

On the average, each additional conduct symptom in childhood was associated with a 32% increased risk of the adverse outcomes in emerging adulthood (mean hazard ratio = 1.32; range = 1.16, 1.56). A latent childhood conduct problems factor predicted the internalizing factor in emerging adulthood (βboys = .24, standard error, SE = 0.03; βgirls = .17, SE = 0.03), above and beyond its association with the externalizing (βboys = 0.21, SE = 0.04; βgirls = 0.17, SE = 0.05) and general factors (βboys = 0.45, SE = 0.03; βgirls = 0.34, SE = 0.04). These associations were differentially influenced by genetic and environmental factors.

Conclusions

It is important to monitor boys and girls with conduct problems not only for future externalizing problems, but also for future internalizing problems. Prevention of specific outcomes, however, might require interventions at different levels.
Performance and Penalties in Year 1 of the Skilled Nursing Facility Value‐Based Purchasing Program
Authors: Qi Andrew C. , Luke Alina A. , Crecelius Charles , Joynt Maddox Karen E.
Published: December 2019

BACKGROUND/OBJECTIVES

Launched in October 2018, Medicareʼs Skilled Nursing Facility Value‐Based Purchasing (SNF VBP) program mandates financial penalties for SNFs with high 30‐day readmission rates. Our objective was to identify characteristics of SNFs associated with provider performance under the program.

DESIGN

Retrospective cross‐sectional analysis using Nursing Home Compare data for the 2019 SNF VBP. Facility‐level regressions examined the relationship between structural characteristics (nursing home size, rurality, profit status, hospital affiliation, region, and Star Ratings) and patient characteristics (neighborhood income, race/ethnicity, dual eligibility, disability, and frailty) and facility performance.

SETTING

US Medicare.

PARTICIPANTS

A total of 14 558 SNFs.

MEASUREMENTS

The 2019 SNF VBP performance scores and penalties.

RESULTS

Nationally, 72% (10 436) of SNFs were penalized; 21% (2996) received the maximum penalty of 1.98%. In multivariate analyses, rural SNFs were less likely to be penalized (odds ratio [OR] = 0.85; 95% confidence interval [CI] = 0.78‐0.92; P < .001; vs urban), while small SNFs were more likely to be penalized (≤70 beds: OR = 1.28; 95% CI = 1.15‐1.42; P < .001; 71‐120 beds: OR = 1.15; 95% CI = 1.05‐1.26; P = .003; vs >120 beds). SNFs with lower nurse staffing had higher odds of penalties (low: OR = 1.15; 95% CI = 1.03‐1.27; P = .010; vs high); nonprofit and government‐owned SNFs had lower odds of penalties (OR = 0.79; 95% CI = 0.72‐0.87; P < .001; government: OR = 0.72; 95% CI = 0.61‐0.84; P < .001; vs for profit); and SNFs with higher Star Ratings had lower odds of penalties (5 stars: OR = 0.47; 95% CI = 0.40‐0.54; P < .001; vs 1 star). In terms of patient population, SNFs located in low‐income ZIP codes (OR = 1.17; 95% CI = 1.03‐1.34; P = .019) or serving a high proportion of frail patients (OR = 1.39; 95% CI = 1.21‐1.60; P < .001) were more likely to be penalized than other SNFs. SNFs with high proportions of dual, black, Hispanic, or disabled patients did not have higher odds of penalization.

CONCLUSION

Structural and patient characteristics of SNFs may significantly impact provider performance under the SNF VBP. These findings have implications for policy makers and clinical leaders seeking to improve quality and avoid unintended consequences with VBP in SNFs. J Am Geriatr Soc 68:826–834, 2020
A profile of mental health and behaviour in Prader–Willi syndrome
Authors: Feighan S.‐M. , Hughes M. , Maunder K. , Roche E. , Gallagher L.
Published: December 2019

Background

Prader–Willi syndrome (PWS) is a neurogenetic syndrome with an associated behavioural phenotype and a high incidence of behaviours of concern and psychiatric co‐morbidity. These associated behaviours and co‐morbidities are not well addressed by existing interventions, and they impact significantly on affected individuals and their caregivers.

Methods

We undertook a national survey of the needs of individuals with PWS and their families in Ireland. In this paper, we report on the parent/caregiver‐reported mental health, behavioural and access to services.

Results

Over 50% of individuals with PWS in this survey had at least one reported psychiatric diagnosis, the most common diagnosis was anxiety. The most commonly reported behaviours in children were skin picking, repetitive questioning, difficulty transitioning and non‐compliance. The same four behaviours were reported by caregivers as being the most commonly occurring in adolescents and adults in addition to food‐seeking behaviours. Increased needs for mental health services were also reported by caregivers. Individuals with PWS had an average wait of 22 months for an appointment with a psychologist and 4 months for an appointment with a psychiatrist.

Conclusion

This study highlighted high levels of psychiatric co‐morbidities and behavioural concerns in individuals with PWS in Ireland. The findings of this study suggest that there is an urgent need to provide specialist psychiatric and behavioural interventions to manage complex mental health and behavioural needs to better support individuals with PWS and reduce caregiver burden.
Barriers and Facilitators to School‐Based Health Centers: pilot Data From 3 Sites in Georgia
Authors: Zarate Raul Perez , Johnson Leigh , Mogendi Simon , Hogue Carol , Johnson Veda , Gazmararian Julie
Published: December 2019

BACKGROUND

School‐based health centers (SBHCs) provide opportunities for offering quality service to underserved populations. The objectives of this study were to: (1) document the SBHC process at different locations and evaluate their similarities and differences; (2) explore SBHC clinic staff satisfaction; and (3) identify facilitators and barriers to utilizing SBHCs.

METHODS

Three Georgia SBHCs located in either predominantly Caucasian, African American, or Hispanic elementary schools were included in this study. Mixed methods data collection efforts included: (1) observational assessment of each SBHC; (2) interviews with 7 clinic administrators and staff; and (3) focus group discussions (N = 5) with parents of children that do and do not utilize SBHCs.

RESULTS

Observational assessments indicated some clinics have more resources available than others. In‐depth interviews found that centers are functioning at capacity, with potential for expansion and greater workload. Focus groups revealed that parents are satisfied with services provided, the price of the care, and the convenience of the centers. However, barriers have made utilization difficult for lower income families.

CONCLUSIONS

Although most SBHC goals are being met, staff realize that further development and funding must be obtained to meet the needs of their communities.
Slow zeaxanthin accumulation and the enhancement of CP26 collectively contribute to an atypical non‐photochemical quenching in macroalga Ulva prolifera under high light
Authors: Gao Shan , Zheng Zhenbing , Wang Jing , Wang Guangce
Published: December 2019

Non‐photochemical quenching (NPQ) is an important photoprotective mechanism in plants, which dissipates excess energy and further protects the photosynthetic apparatus under high light stress. NPQ can be dissected into a number of components: qE, qZ, and qI. In general, NPQ is catalyzed by two independent mechanisms, with the faster‐activated quenching catalyzed by the monomeric light‐harvesting complex (LHCII) proteins and the slowly activated quenching catalyzed by LHCII trimers, both processes depending on zeaxanthin but to different extent. Here, we studied the NPQ of the intertidal green macroalga, Ulva prolifera, and found that the NPQ of U. prolifera lack the faster‐activated quenching, and showed much greater sensitivity to dithiothreitol (DTT) than to dicyclohexylcarbodiimide (DCCD). Further results suggested that the monomeric LHC proteins in U. prolifera included only CP29 and CP26, but lacked CP24, unlike Arabidopsis thaliana and the moss Physcomitrella patens. Moreover, the expression levels of CP26 increased significantly following exposure to high light, but the concentrations of the two important photoprotective proteins (PsbS and light‐harvesting complex stress‐related [LhcSR]) did not change upon the same conditions. Analysis of the xanthophyll cycle pigments showed that, upon exposure to high light, zeaxanthin synthesis in U. prolifera was gradual and much slower than that in P. patens, and could effectively be inhibited by DTT. Based on these results, we speculate the enhancement of CP26 and slow zeaxanthin accumulation provide an atypical NPQ, making this green macroalga well adapted to the intertidal environments.
Stressor reactivity to insufficient sleep and its association with body mass index in middle‐aged workers
Authors: Vigoureux Taylor F. D. , Lee Soomi , Buxton Orfeu M. , Almeida David M.
Published: December 2019

There is evidence that insufficient sleep and more stressors are individually associated with poor metabolic health outcomes. Examining sleep and stressors jointly may account for greater variability in health outcomes; however, we know little about the combined effect of both insufficient sleep and more stressors on metabolic health. This study examined whether experiencing more stressors in response to insufficient sleep (“stressor reactivity to insufficient sleep”) was associated with body mass index in middle‐aged workers. One‐hundred and twenty‐seven participants (Mage = 45.24 ± 6.22 years) reported nightly sleep characteristics and daily stressors on 8 consecutive days. We collected height and weight measurements to calculate body mass index (kg m−2). On average, workers reported more stressors following nights with shorter‐than‐usual sleep duration or poorer‐than‐usual sleep quality (negative slope means higher stressor reactivity to insufficient sleep). When examining stressor reactivity to insufficient sleep with insufficient sleep represented by shorter‐than‐usual sleep duration, compared with those with average stressor reactivity to insufficient sleep (within ±½ SD; reference), workers with high stressor reactivity to insufficient sleep (≤−½ SD) had higher body mass index (B = 3.24, p < .05). The body mass index of these workers fell in the obese range. There was no difference in body mass index between workers with low stressor reactivity to insufficient sleep (≥+½ SD) and the reference group. When examining stressor reactivity to insufficient sleep with insufficient sleep represented by poorer‐than‐usual sleep quality, stressor reactivity to insufficient sleep was not significantly associated with body mass index. Results suggest that middle‐aged workers with higher stressor reactivity to insufficient sleep duration may be at greater risk for obesity. Results may inform future studies on interventions for improving sleep and reducing stress in middle‐aged workers.
The effect of anticipatory stress and openness and engagement on subsequently perceived sleep quality–An Experience Sampling Method study
Authors: Block Victoria J. , Meyer Andrea H. , Miché Marcel , Mikoteit Thorsten , Hoyer Jürgen , Imboden Christian , Bader Klaus , Hatzinger Martin , Lieb Roselind , Gloster Andrew T.
Published: December 2019

High stress levels can influence sleep quality negatively. If this also applies to anticipatory stress is poorly documented, however. Across insomnia severity levels, this study examined participants’ evening levels of (a) anticipatory stress and (b) their skills hypothesized to downregulate the impact of stress, namely openness to internal experiences and continuous engagement in meaningful activities (openness and engagement) and their association with the quality of the subsequent night's sleep. The moderating role of insomnia severity was also tested. We used a quasi‐experimental longitudinal design with Experience Sampling Method using smartphones over the course of 1 week (3,976 assessments; 93.2% of prompted queries). Participants recorded their sleep quality, anticipatory stress, and openness and engagement within their daily context. Participants included in the study were diagnosed with major depressive disorder (n = 118), social phobia (n = 47) or belonged to the control group (n = 119). Both anticipatory stress and openness and engagement predicted subsequent sleep quality. Diagnostic group was associated with overall sleep quality, but did not interact with the predictors. These findings were invariant across levels of self‐reported insomnia severity. Furthermore, openness and engagement and anticipatory stress did not interact in their effect on sleep quality. The results suggest that both stress reduction and increased openness and engagement are associated with improved subjective sleep quality on a day to day basis, regardless of insomnia severity. Targeting these variables may help improve sleep quality. Future research should disentangle the effects of openness and engagement on anticipatory stress.
A Flexible Univariate Autoregressive Time‐Series Model for Dispersed Count Data
Authors: Sellers Kimberly F. , Peng Stephen J. , Arab Ali
Published: December 2019

Integer‐valued time series data have an ever‐increasing presence in various applications (e.g., the number of purchases made in response to a marketing strategy, or the number of employees at a business) and need to be analyzed properly. While a Poisson autoregressive (PAR) model would seem like a natural choice to model such data, it is constrained by the equi‐dispersion assumption (i.e., that the variance and the mean equal). Hence, data that are over‐ or under‐dispersed (i.e., have the variance greater or less than the mean respectively) are improperly modeled, resulting in biased estimates and inaccurate forecasts. This work instead develops a flexible integer‐valued autoregressive model for count data that contain over‐ or under‐dispersion. Using the Conway–Maxwell–Poisson (CMP) distribution and related distributions as motivation, we develop a first‐order sum‐of‐CMP's autoregressive (SCMPAR(1)) model that will instead offer a generalizable construct that captures the PAR, and versions of what we refer to as a negative binomial AR model, and binomial AR model respectively as special cases, and serve as an overarching representation connecting these three special cases through the dispersion parameter. We illustrate the SCMPAR model's flexibility and ability to effectively model count time series data containing data dispersion through simulated and real data examples.
How Does Government Control Affect Firm Value? New Evidence for China
Authors: Abolhassani Marzieh , Wang Zhi , de Haan Jakob
Published: December 2019

The role of government involvement in firms has received a lot of attention in the last few decades. Government involvement could result in a ‘supporting hand’ and a ‘grabbing hand’. This paper investigates how government control influences the financial performance of Chinese listed firms. We use a panel data set of firms publicly traded on the stock exchanges of Shanghai and Shenzhen over the period 2009‐2013. Our dataset includes 5501 firm‐year observations. Our results suggest that government control of firms, measured by the shareholdings that are directly and indirectly controlled by the government, is negatively related with firms’ financial performance. More specifically, the return on assets, the return on equity and the market‐to‐book ratio are, on average, 1.3%, 2.0% and 8.2% lower for government‐controlled firms. Both central and local government control is undermining firm performance. These findings provide support for the ‘grabbing hand’ theory of the government. Our results also suggest that the negative effect of government control becomes stronger when firm profitability is higher. Firms with a poor financial performance benefit from government control, which supports the ‘supporting hand’ theory of the government.
You say it, we say it, but how do we use it? Communities of practice: A critical analysis
Authors: McGrath Cormac , Liljedahl Matilda , Palmgren Per J.
Published: December 2019

Objectives

As educational theories are increasingly used in medical education research there are concerns over how these theories are used, how well they are presented and what the authors intend. Communities of practice (CoP) is one example of an often‐used theory and conceptual framework. This paper presents a critical analysis of how CoP theory is used in medical education research.

Methods

A critical literature analysis was undertaken of articles published between 1998 and 2018 in eight internationally recognised medical education journals. From a total of 541 articles, 80 articles met the inclusion criteria and were analysed and mapped according to various patterns of use.

Results

We discerned five categories of use, two misleading and cosmetic, off target and cosmeticising, and three functional, framing, lensing and transferring. A considerable number of articles either misrepresented the point of communities of practice or used it in a cosmetic fashion. The remainder used the theory to frame an ongoing study in relation to other work, as a lens through which to design the study and collect or analyse data, or as a way of discussing or demonstrating the transferability of the findings.

Conclusions

We conclude that almost half of the reviewed articles did not offer a functional and rigorous definition of what is meant by CoP; instead, they used it in a potentially misleading or cosmetic manner. This study therefore calls on editors, reviewers and authors alike to increase clarity and quality in the application of CoP theory in medical education.
Focused ethnography as an approach in medical education research
Authors: Andreassen Pernille , Christensen Mette K. , Møller Jane E.
Published: December 2019

Context

Over recent decades, the use of qualitative methodologies has increased in medical education research. These include ethnographic approaches, which have been used to explore complex cultural norms and phenomena by way of long‐term engagement in the field of research. Often, however, medical education consists of short‐term episodes that are not bound to single sites, but take place in a myriad of locations and contexts such as classrooms, examination stations, clinical settings and online. This calls for methodologies that allow us to grasp what is at stake in an increasingly multifaceted and diverse field.

Methods

In this article, we direct attention to focused ethnography, which has emerged as a useful, suitable and feasible applied qualitative research approach, and which uses adapted classic ethnographic methods, such as direct observation, to gain new insights and nuanced understandings of distinct phenomena, themes and interactions in specific settings in medical education (eg the learning potential of ward rounds, or how hierarchical positions affect learning situations). We introduce methodological key features of focused ethnography to give insights into how the approach can be used, and we offer examples of how the method has been used in medical education research to show how it has contributed in different ways to the field of medical education research. Furthermore, we address and discuss some of the main challenges and limitations of the approach.

Conclusions

Focused ethnography offers a methodological approach that sheds light over limited and well‐defined social episodes and interactions. Precisely because the field of medical education consists to a large degree of such fragmented interactions, focused ethnography can be seen as a methodology tailored to these characteristics and should become an integrated part of the toolkit of medical education research.
MicroRNA6443‐mediated regulation of FERULATE 5‐HYDROXYLASE gene alters lignin composition and enhances saccharification in Populus tomentosa
Authors: Fan Di , Li Chaofeng , Fan Chunfen , Hu Jian , Li Jianqiu , Yao Shu , Lu Wanxiang , Yan Yangyang , Luo Keming
Published: December 2019

Ferulate 5‐hydroxylase (F5H) is a limiting enzyme involved in biosynthesizing sinapyl (S) monolignol in angiosperms. Genetic regulation of F5H can influence S monolignol synthesis and therefore improve saccharification efficiency and biofuel production. To date, little is known about whether F5H is post‐transcriptionally regulated by endogenous microRNAs (miRNAs) in woody plants.

Here, we report that a microRNA, miR6443, specifically regulates S lignin biosynthesis during stem development in Populus tomentosa.

In situ hybridization showed that miR6443 is preferentially expressed in vascular tissues. We further identified that F5H2 is the direct target of miR6443. Overexpression of miR6443 decreased the transcript level of F5H2 in transgenic plants, resulting in a significant reduction in S lignin content. Conversely, reduced miR6443 expression by short tandem target mimics (STTM) elevated F5H2 transcripts, therefore increasing S lignin composition. Introduction of a miR6443‐resistant form of F5H2 into miR6443‐overexpression plants restored lignin ectopic composition, supporting that miR6443 specifically regulated S lignin biosynthesis by repressing F5H2 in P. tomentosa. Furthermore, saccharification assays revealed decreased hexose yields by 7.5–24.5% in miR6443‐overexpression plants compared with the wild‐type control, and increased hexoses yields by 13.2–14.6% in STTM6443‐overexpression plants.

Collectively, we demonstrate that miR6443 modulates S lignin biosynthesis by specially regulating F5H2 in P. tomentosa.
Comparison between Percutaneous Screw Fixation and Plate Fixation via Sinus Tarsi Approach for Calcaneal Fractures: An 8–10‐Year Follow‐up Study
Authors: Weng Qi‐hao , Dai Gao‐le , Tu Qi‐ming , Liu Yang , Lutchooman Vinesh , Hong Jian‐jun , Yu Yang
Published: December 2019

Objective

To assess the long‐term outcomes after percutaneous reduction (PR) and screw fixation versus plate fixation via the sinus tarsi approach (STA) for displaced intra‐articular calcaneal fractures (DIACF).

Methods

This retrospective study included a total of 150 patients (June 2008–August 2011), comprising 85 men and 65 women (mean age, 38.4 years), who were assigned to the PR group or the STA group. The inclusion criteria were DIACF (>2 mm) including Sanders type II and III, closed fracture, unilateral fracture, no history of smoking or no smoking during hospitalization and 3 months after surgery, and follow‐up time not less than 8 years. The exclusion criteria were clear surgical contraindications (severe cardiovascular and cerebrovascular diseases), local or systemic infection symptoms, diagnosis with diabetes or lower extremity vascular disease, and Sanders type IV or open fractures. Outcomes were assessed by means of the American Orthopedic Foot and Ankle Society (AOFAS) hindfoot scores, radiographic images, and postoperative complications.

Results

The mean follow‐up period was 8.7 years (range, 8.0–10.0 years). The AOFAS scores in the PR group during the follow‐up period were 54.2 ± 5.1, 85.8 ± 4.0, 88.1 ± 3.8, 87.9 ± 3.6, 87.8 ± 3.9, 86.9 ± 3.9, respectively, and in the STA group were 55.0 ± 5.6, 84.5 ± 5.2, 87.1 ± 3.8, 86.9 ± 3.8, 87.7 ± 3.3, and 87.6 ± 2.8, respectively. There was no significant difference in AOFAS scores, Bohler's angle, Gissane's angle, calcaneal length, and height between the two groups (P > 0.05). The good to excellent rate of the PR group (80.8%) was less than that of the STA group (91.7%) (P = 0.055). For Sanders III fractures, the good to excellent rate of the PR group (33.3%) was less than that of the STA group (76.9%) (P = 0.029). For calcaneal width recovery, the STA group performed better than the PR group (P < 0.05). The incidence of postoperative complications in the PR group (12.8%) was lower than that in the STA group (27.8%) (P = 0.026), of which the incidence of wound complications was 3.8% in the PR group and 13.9% in the STA group (P = 0.041). In addition, there was no significant difference in other postoperative complications such as sural nerve injury, peroneus longus and brevis muscle injury, calcaneal valgus symptoms, lateral impingement symptoms, and subtalar arthritis (P > 0.05).

Conclusion

From the 8–10‐year follow‐up results of PR and STA as surgical procedures for the treatment of DIACF, it was found that there was no significant difference in the overall efficacy between them. STA was found to be superior to the PR in terms of the recovery of calcaneal width, providing more stable fixation for Sanders III fractures. PR was found to be more effective in reducing wound complications.
Genetic and signalling pathways of dry fruit size: targets for genome editing‐based crop improvement
Authors: Hussain Quaid , Shi Jiaqin , Scheben Armin , Zhan Jiepeng , Wang Xinfa , Liu Guihua , Yan Guijun , King Graham J. , Edwards David , Wang Hanzhong
Published: December 2019

Fruit is seed‐bearing structures specific to angiosperm that form from the gynoecium after flowering. Fruit size is an important fitness character for plant evolution and an agronomical trait for crop domestication/improvement. Despite the functional and economic importance of fruit size, the underlying genes and mechanisms are poorly understood, especially for dry fruit types. Improving our understanding of the genomic basis for fruit size opens the potential to apply gene‐editing technology such as CRISPR/Cas to modulate fruit size in a range of species. This review examines the genes involved in the regulation of fruit size and identifies their genetic/signalling pathways, including the phytohormones, transcription and elongation factors, ubiquitin‐proteasome and microRNA pathways, G‐protein and receptor kinases signalling, arabinogalactan and RNA‐binding proteins. Interestingly, different plant taxa have conserved functions for various fruit size regulators, suggesting that common genome edits across species may have similar outcomes. Many fruit size regulators identified to date are pleiotropic and affect other organs such as seeds, flowers and leaves, indicating a coordinated regulation. The relationships between fruit size and fruit number/seed number per fruit/seed size, as well as future research questions, are also discussed.
Intervening in sibling competition for assimilates by controlled pollination prevents seed abortion under postpollination drought in maize
Authors: Shen Si , Liang Xiao‐Gui , Zhang Li , Zhao Xue , Liu Yun‐Peng , Lin Shan , Gao Zhen , Wang Pu , Wang Zhi‐Min , Zhou Shun‐Li
Published: December 2019

During maize production, drought throughout the flowering stage usually induces seed abortion and yield losses. The influence of postpollination drought stress on seed abortion and its underlying mechanisms are not well characterized. By intervening in the competition for assimilates between kernel siblings under different degrees of postpollination drought stresses accompanied by synchronous pollination (SP) and incomplete pollination (ICP) approaches, the mechanisms of postpollination abortion were investigated at physiological and molecular levels. Upon SP treatment, up to 15% of the fertilized apical kernels were aborted in the drought‐exacerbated competition for assimilates. The aborted kernels exhibited weak sucrose hydrolysis and starch synthesis but promoted the synthesis of trehalose‐6‐phosphate and ethylene. In ICP where basal pollination was prevented, apical kernel growth was restored with reinstated sucrose metabolism and starch synthesis and promoted sucrose and hexose levels under drought stress. In addition, the equilibrium between ethylene and polyamine in response to the drought and pollination treatments was associated with the abortion process. We conclude that competition for assimilates drives postpollination kernel abortion, whereas differences in sugar metabolism and the equilibrium between ethylene and polyamines may be relevant to the “live or die” choice of kernel siblings during this competition.
Functional analysis of mTERF5 and mTERF9 contribution to salt tolerance, plastid gene expression and retrograde signalling in Arabidopsis thaliana
Authors: Núñez‐Delegido E. , Robles P. , Ferrández‐Ayela A. , Quesada V.
Published: December 2019

We previously showed that Arabidopsis mda1 and mterf9 mutants, defective in the chloroplast‐targeted mitochondrial transcription termination factors mTERF5 and mTERF9, respectively, display altered responses to abiotic stresses and abscisic acid (ABA), as well as perturbed development, likely through abnormal chloroplast biogenesis.

To advance the functional analysis of mTERF5 and mTERF9, we obtained and characterized overexpression (OE) lines. Additionally, we studied genetic interactions between sca3‐2, affected in the plastid‐RNA polymerase RpoTp, and the mda1‐1 and mterf9 mutations. We also investigated the role of mTERF5 and mTERF9 in plastid translation and plastid‐to‐nucleus signalling.

We found that mTERF9 OE reduces salt and ABA tolerance, while mTERF5 or mTERF9 OE alter expression of nuclear and plastid genes. We determined that mda1‐1 and mterf9 mutations genetically interact with sca3‐2. Further, plastid 16S rRNA levels were reduced in mda1‐1 and mterf9 mutants, and mterf9 was more sensitive to chemical inhibitors of chloroplast translation. Expression of the photosynthesis gene LHCB1, a retrograde signalling marker, was differentially affected in mda1‐1 and/or mterf9 compared to wild‐type Col‐0, after treatments with inhibitors of carotenoid biosynthesis (norflurazon) or chloroplast translation (lincomycin). Moreover, mterf9, but not mda1‐1, synergistically interacts with gun1‐1, defective in GUN1, a central integrator of plastid retrograde signals.

Our results show that mTERF9, and to a lesser extent mTERF5, are negative regulators of salt tolerance and that both genes are functionally related to RpoTp, and that mTERF9 is likely required for plastid ribosomal stability and/or assembly. Furthermore, our findings support a role for mTERF9 in retrograde signalling.
Periodontal therapeutics: Current host‐modulation agents and future directions
Authors: Golub Lorne M. , Lee Hsi‐Ming
Published: December 2019

With the recognition in the 1960s and 1970s of the periodontopathic importance of the microbial biofilm and its specific anaerobic microorganisms, periodontitis was treated as an infectious disease (more recently, as a dysbiosis). Subsequently, in the 1980s, host‐response mechanisms were identified as the mediators of the destruction of the collagen‐rich periodontal tissues (gingiva, periodontal ligament, alveolar bone), and the periodontopathogens were now regarded as the "trigger" of the inflammatory/collagenolytic response that characterizes actively destructive periodontitis. Also at this time a new pharmacologic strategy emerged, entitled "host‐modulation therapy", based on 2 major findings: (1) that the ability of tetracycline antibiotics to inhibit periodontal breakdown was due (in large part) to their previously unrecognized ability to inhibit the host‐derived matrix metalloproteinases (notably, the collagenases, gelatinases, macrophage metalloelastase), and by mechanisms unrelated to the antimicrobial properties of these medications; and (2) that nonsteroidal anti‐inflammatory drugs, such as flurbiprofen, again by nonantimicrobial mechanisms, could reduce the severity of periodontitis (however, the adverse effects of long‐term therapy precluded their development as safe and effective host‐modulatory agents). Additional mechanistic studies resulted in the development of novel nonantimicrobial formulations (Periostat® [now generic] and Oracea®) and compositions of tetracyclines (notably chemically modified tetracycline‐3) as host‐modulator drugs for periodontitis, arthritis, cardiovascular and pulmonary diseases, cancer, and, more recently, for local and systemic bone loss in postmenopausal women. Identification of the cation‐binding active site in the tetraphenolic chemically modified tetracycline molecules drove the development of a new category of matrix metalloproteinase‐inhibitor compounds, with a similar active site, the biphenolic chemically modified curcumins. A lead compound, chemically modified curcumin 2.24, has demonstrated safety and efficacy in vitro, in cell culture, and in vivo in mouse, rat, rabbit, and dog models of disease. In conclusion, novel host‐modulation compounds have shown significant promise as adjuncts to traditional local therapy in the clinical management of periodontal disease; appear to reduce systemic complications of this all‐too‐common "inflammatory/collagenolytic" disease; and Oracea® is now commonly prescribed for inflammatory dermatologic diseases.
Advances in implant therapy in North America: Improved outcomes and application in the compromised dentition
Authors: Saito Hanae , Aichelmann‐Reidy Mary Beth , Oates Thomas W.
Published: December 2019

Advances in dental implant therapy have strengthened our understanding of the management of the implant‐soft tissue interface, with site‐specific implications ranging from marginal tissue management and esthetics to immediate placement and restoration, and extend to patient‐level implications of systemic conditions. The advancements in implant therapy have placed an increased emphasis on patient‐centered outcomes. In this paper, the following conclusions can be drawn: improvements in both esthetics and long‐term maintenance have been guided by the study of the marginal peri‐implant tissues leading to innovations in implant design along the implant‐abutment interface. Patient expectations for simple and realistic time intervals for treatment have promoted the use of immediate implant placement and restoration. The expansion of implant therapy offers implant options for patients with medical conditions, with one in particular, diabetes mellitus a focus of this paper. Studies on patients with diabetes are supporting the development of evidence‐based treatment considerations with broader application and greater benefits for the use of implant therapy across a larger patient population. This paper is not intended to offer a comprehensive review, but offers a representative review of some of the many contributions of USA and North American clinicians to the global scientific dialogue that has guided the development of dental implant therapy.
Probiotics, including nisin‐based probiotics, improve clinical and microbial outcomes relevant to oral and systemic diseases
Authors: Nguyen Trang , Brody Hanna , Lin Guo‐Hao , Rangé Hélène , Kuraji Ryutaro , Ye Changchang , Kamarajan Pachiyappan , Radaic Allan , Gao Li , Kapila Yvonne
Published: December 2019

The effects of probiotic supplementation on systemic health and gastrointestinal diseases have been investigated in numerous studies. The aim of this review is to provide an overview of probiotics and their effects on periodontal health. Probiotics show beneficial effects as adjunctive therapeutics and as stand‐alone agents in the treatment and prevention of gingivitis as well as specific clinical parameters of periodontitis. This review focuses on the clinical and microbiological aspects of probiotics in the context of health, gingivitis, and periodontitis. In addition, a special focus on nisin‐producing probiotics and nisin itself showcase their significant potential for oral and systemic use.